{"paper_id":"277819c6-1c85-4ff2-abe0-e608341e4202","body_text":"Transcriptome profiling comparison between the salt sensitive and tolerant cultivars of sweet potato reveals the key regulatory pathways in response to high salt stress | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Transcriptome profiling comparison between the salt sensitive and tolerant cultivars of sweet potato reveals the key regulatory pathways in response to high salt stress Haiyang Zhang, Meng Li, Junlin Li, Dongyang Li, Chuanjie Chen, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8517679/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 14 You are reading this latest preprint version Abstract Sweet potato ( Ipomoea batatas (L.) Lam.) is an important food crop with high nutritional and economic value. However, the mechanism regulating the resistance of different sweet potato varieties to salt stress is unclear. Here, a systematic was conducted with the salt sensitive variety YS25 and salt tolerant variety FMG in response to salt stress. Phenotypic and physiochemical analyses demonstrated that under salt stress condition, the growth of FMG was less affected. It showed more vigorous growth, accompanied with less chlorophyll loss and sodium, malondialdehyde (MDA) and H 2 O 2 accumulation, than did YS25. It also showed higher soluble sugar content and superoxide dismutase (SOD), guaiacol peroxidase (POD) and catalase (CAT) enzymatic activity. Further transcriptomic analyses respectively identified 7370 and 7068 differential expression genes (DEGs) in YS25 and FMG. Gene ontology (GO) term analyses revealed that they were significantly rich in the terms of \"biological processes\" and \"molecular functions\". Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses showed that DEGs in the salt tolerant variety FMG were significantly enriched in the zeatin biosynthesis pathway, the starch and sucrose metabolis pathway, the galactose metabolis pathway, the nitrogen metabolis pathway and the flavonoid biosynthesis pathway. Expressions of the key genes in these regulatory pathways were further confirmed with quantitative real-time polymerase chain reaction (qRT-PCR) assays in the salt sensitive sweet potato cultivar XGH and the salt tolerant cultivar QT. Our studies provide a novel approach to the mining of new gene targets usable for breeding of salt tolerant sweet potato. Sweet potato Transcriptome Salt resistance Regulatory pathways Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Key message Key pathways in different sweet potato varieties in response to salt stress identified through transcriptomic profiling. Introduction Soil salinization is one of the common abiotic stresses seriously affecting agricultural productivity in the world (Li et al., 2025; Lin et al., 2025). Upon salt stress, the ability of plant roots to absorb nutrients and water decreased, leading to limited plant growth (Cui et al., 2025; Munns and Tester, 2008; Zhao et al., 2021). At the same time, the accumulation of sodium ions in plants changed the transcription levels of many genes involved in photosynthesis, ion balance, metabolism and synthesis (Mansour et al., 2021; Muchate et al., 2016; Singh et al., 2021; Zhang et al., 2016). The response of plants to salt stress is a complex and diverse tolerance mechanism formed by the activation of thousands of genes (Zelm et al., 2020; Zhu, 2006). Under salt stress condition, Na + was excreted and separated by plant ion transporters to maintain intracellular ion balance (Flowers and Colmer, 2008; Wang et al., 2018). The expression of a large number of peroxidase genes in the peroxidase pathway alleviated the damage of high levels of reactive oxygen species (ROS) induced by salt stress on plant DNAs, proteins and lipids (Li et al., 2023). Many Transcription factors (TFs), such as bZIP, MYB, WRKY and AP2/ERF, played an important role in regulating signal transduction and transcription of genes related to salt stress response (Meng et al., 2020). Sweet potato ( Ipomoea batatas (L.) Lam.) is an important food crop (Adu et al., 2025; Rickman et al., 2025). Over the past 20 years, the production of sweet potato have increased significantly, and sweet potato have become the fifth most important crop, right after rice, wheat, maize and sorghum (Rickman et al., 2025). Sweet potato is a salt sensitive plant (Luo et al., 2017). The growth and yield of it were often affected under saline soil condition (Zhang et al., 2017). Therefore, it is of great significance to explore salt tolerant genes and understand their physiological and molecular mechanisms for the breeding of salt tolerant sweet potato varieties. To date, a great number of abiotic stress associated genes have been identified in sweet potato, and their functions in plants were studied (Hu et al., 2024; Liu et al., 2023; Meng et al., 2023; Wang et al., 2024; Wang et al., 2025; Wu et al., 2024; Yang et al., 2024). For example, sweet potato IbGCS , IbMYB48 , IbbZIP1 improved the drought and salt stress resistance of transgenic plants (Kang et al., 2019; Yang et al., 2024; Zhao et al., 2022). IbMYB330 , a sweet potato MYB transcription factor, enhanced the tolerance of transgenic tobacco to drought and salt stress (Wang et al., 2024). Overexpression of IbCBF3 increased the tolerance of transgenic sweet potato to low temperature and drought stress (Rong et al., 2017). Transcriptome sequencing technology has become one of the common techniques used to study how plants respond to abiotic stress (Ouertani et al., 2021). In Taxus chinensis , transcriptome analysis showed that transcription factors, along with genes associated with oxidative stress, starch and sucrose metabolism, and ion homeostasis, played crucial roles in the response to salt stress (Li et al., 2023). The ability of plants to resist salinity stress differed both among different species and within the same species (Munns et al., 2008). A great significance of ion homeostasis in the rapid adaptive response to salt stress in two different varieties of Chinese cabbage was discovered through transcriptome comparison analyses (Li et al., 2021). In sweet potato, transcriptomic assays in the roots of the salt sensitive variety Lizixiang and the salt tolerant line ND98 indicated that the JA signalling was the important pathway in response to salt stress (Zhang et al., 2017). However, in two other sweet potato varieties, the salt tolerant cultivar Xushu 22 and the salt sensitive cultivar Xushu 32, genes related to ion accumulation, stress signalling, transcriptional regulation, plant hormone signalling and secondary metabolite accumulation played an important role in salt stress response (Meng et al., 2020). In this study, two salt sensitive cultivars, YS25 and XGH, and two salt tolerant cultivars, FMG and QT, were used to dissect the mechanism of how they respond differently to high salt stress. RNA-seq analysis identified the candidate genes and pathways involved in salt stress response, which laid a solid foundation for the future study on salt tolerance response in sweet potato. Materials and Methods Plant materials and salt treatments The root tubes and shoot branches of \"Yan Shu 25\" (designated as YS25), \"Feng Mi Guan\" (designated as FMG), \"Xi Gua Hong\" (designated as XGH) and \"Qing Tian\" (designated as QT) were taken from Gaoling Town, Muping District, Yantai City, Shandong Province, China. The branches of YS25, FMG, XGH and QT were planted in triangle flasks containing H 2 O, and cultured in plant growth chamber under a 14/10 h light/dark period with a 70–75% relative humidity at 24°C. The culture solution was changed every 2 days. For salt resistance assays, two-week-old plantlets at the same size and growth status were treated with 0 mM, 100 mM, 200 mM, 300 mM and 400 mM NaCl. The critical concentration for 2-week-old sweet potato seedlings was 300 mM NaCl. The treatment culture solution was changed every 2 days. For RNA-seq, leaves from at least 9 plants of each group after 2 days treatment were harvested and stored at -80°C. Three biological replicates were performed. Determination of physiological indexes For the determination of ion content and peroxidase related content, leaves from at least 10 plants of each group after 4 days treatment were harvested. Each treatment included 3 biological replicates. Leaves were collected to determine the SOD, POD, and CAT activities, and the content of chlorophyll, H 2 O 2 , MDA, soluble sugar, Na + and K + under both normal and salt stress conditons. Transcriptome sequencing, differentially expressed gene screening and functional enrichment analysis Total RNA was extracted using TRIzol® reagents according to the manufacturer's instructions. RNA quality was determined and quantified with 5300 Bioanalyzer (Agilent) and ND-2000 (NanoDrop Technologies). High quality RNA samples were used to construct sequencing libraries. The sweet potato RNA-SEQ transcriptome libraries were obtained from Illumina® single-stranded mRNA Prep, Ligation (San Diego, CA), with a total RNA concentration of 1µg. The sequencing libraries were performed on the DNBSEQ-T7 platform (PE150) using the DNBSEQ-T7RS Reagent Kit (FCL PE150) version 3.0. The original paired end reads are trimmed and quality controlled by fastp with default parameters. Then HISAT2 software was used to compare the mapping patterns of clean reads with reference genomes. The mapped readings for each sample are assembled with StringTie in a reference-based method. To identify differentially expressed genes (DEGs), the expression level of each transcript was calculated according to the TPM (the transcripts per million reads) method. RSEM is used to quantify gene abundance. The screening criteria for differentially expressed genes were |log2FC| >=1 and padjust < 0.05. GO functional enrichment and KEGG pathway analysis were performed wiht Goatools and Python scipy software, respectively. Quantitative real-time PCR assays Eight randomly selected genes from the DEGs in the transcriptome were subjected to quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Detailed information regarding the gene-specific primers utilized in this research was shown in Supplementary Table S1 . RNA samples were collected from various sweet potato varieties under normal and salt stress conditions at two time points (0 and 2 days). Complementary DNA (cDNA) was synthesized from the extracted RNA using the HiScript II 1st Strand cDNA Synthesis Kit (Vazyme Biotech, Nanjing, China). Quantitative real-time PCR (qRT-PCR) was carried out using the LightCycler480 Real-Time PCR System along with ChamQTMSYBR® qPCR Master Mix (Vazyme Biotech, Nanjing, China), following the protocol provided by the manufacturer. The relative expression levels of the selected genes were calculated using the 2 −ΔΔCt method, with three independent biological replicates included for each measurement. Statistical analysis The Student’s t-test implemented in the Rbase package was used to assess statistical significance. Three biological replicates and three technical replicates were conducted to generate the mean values and standard deviations (SDs). Significant differences between different samples were determined using the multiple range test at P < 0.05. Results FMG showed more resistant to salt stress than did YS25 Our previous salt tolerance experiments showed that YS25 was a salt sensitive sweet potato variety with yellow flesh, while FMG was a salt tolerant sweet potato variety with white flesh (Fig S1 ). To determine the difference in the resistance response to salt stress between the two types of sweet potato varieties, the 2-week-old YS25 and FMG plants were treated with 0 or 300 mM NaCl for 6 days, respectively (Fig. 1 ). After 2 days of salt treatment, YS25 plants showed a leaf dechlorosis phenotype, while FMG plants grew with green leaves until the 4th day. After 6 days, YS25 plants died, while FMG plants remained alive (Fig. 1 ). Under salt stress conditions, the chlorophyll content in YS25 and FMG plants was severely affected (Fig. 2 A, B). After four days treatment, the chlorophyll content in both YS25 and FMG decreased significantly (Fig. 2 A, B). However, compared to YS25, the chlorophyll content in FMG was less affected by salt stress (Fig. 2 A, B). To explore the impacts of salt stress on ion accumulation in two sweet potato varieties, we examined the content of K + , Na + and the K + / Na + ratio in the leaves of 2-week-old plants. These plants were treated with 0 and 300 mM NaCl for 4 days (Fig. 2 C, D, E). Under normal conditions, there was no difference in K + content in leaves of YS25 and FMG plants. Nevertheless, the Na + content in YS25 leaves was lower than that in FMG leaves (Fig. 2 C, D). Under normal conditions, the content of K + in YS25 and FMG leaves was considerably higher than that of Na + (Fig. 2 C, D). Also, the K + / Na + ratio in YS25 leaves was higher than that in FMG under normal conditions (Fig. 2 E). After salt treatment, salt stress induced the accumulation of Na + in the leaves of both YS25 and FMG (Fig. 2 D). Under salt stress treatment, there was no difference in the K + content between YS25 and FMG leaves (Fig. 2 C). However, more Na + was accumulated in YS25 leaves than in FMG leaves (Fig. 2 D). After salt stress treatment, there was no significant difference in the K + / Na + ratio between YS25 and FMG (Fig. 2 E). Antioxidant defense systems were involved in the salt stress response of sweet potatos To further analyze the different responses of two sweet potato varieties to salt stress, we examined the antioxidant defense system between YS25 and FMG. When NaCl treatment was compared with CK treatment, the contents of MDA, H 2 O 2 and soluble sugar were increased in YS25 and FMG leaves (Fig. 3 A, B, C). The increased MDA and H 2 O 2 level in YS25 were significantly higher than that in FMG (Fig. 3 A, B). On the contrary, the content of soluble sugar in FMG leaves was higher than YS25 under salt stress. (Fig. 3 C). Compared to CK treatment, NaCl treatment significantly increased antioxidant enzyme activity in YS25 and FMG leaves, respectively (Fig. 3 E). Under salt stress treatment, the change trend of antioxidant enzyme activity was the same in the two sweet potato varieties, and the antioxidant enzyme activities of SOD, CAT and POD were increased to different degrees (Fig. 3 D, E, F). However, the SOD, CAT and POD activities were increased significantly in FMG leaves under salt stress compared with YS25 (Fig. 3 D, E, F ). A great number of differentially expressed genes were identified via transcriptome sequencing In order to understand the difference of gene expression response between two sweet potato varieties under salt stress, we performed RNA-seq analysis. The differentially expressed genes (DEGs) in leaves of YS25 and FMG plants after 2 days of 0 mM and 300 mM NaCl treatment were analyzed (Fig. 4 A, B). A high quality transcriptome sequencing, with a multiple bases of Q20 score > 97%, Q30 > 92% and GC percentage > 46%, were generated with IlluminaHiSeq™4000 (Table S2). In our experiment, we obtained 565.6 million original readings from 12 samples (Table S2). After filtering the adapter sequence and low-quality reads, 547.5 million clean reads were obtained (Table S2). To compare the expression of different genes in the transcriptome of two sweet potato varieties under different conditions (control and salt stress) (Fig. 4 A, B). Upon the salt treatment, 7370 and 7068 DEGs, with 3351 and 2725 up-regulated, and 4019 and 4343 down-regulated, were respectively identified in YS25 and FMG (Fig. 4 A, B; Table S3). The quality of RNA-Seq results was successfully validated with qRT-PCR To check the reliability of the RNA-seq data, eight differentially expressed genes (DEGs) were chosen randomly for validation by qRT-PCR. The relative expression levels (Fpkm) of these eight genes in the RNA-seq were verified through qRT-PCR (using the 2 −ΔΔCT method). The results showed consistency in the alterations of gene expression levels between the qRT-PCR and RNA-seq analyses carried out in YS25 and FMG. This suggests that the quality of the RNA-seq data is reliable (Fig S2). The GO enrichment terms of DEGs were different between YS25 and FMG under salt stress condition To investigate the potential role of differentially expressed genes in response to salt stress in different salt-resistant sweet potato varieties, we conducted a comprehensive annotation and genetic ontology terminology analysis. A total number of 821 and 740 GO terms in YS25 and FMG were respectively identified, including 447 BP-related, 91 CC-related and 283 MF-related GO terms in YS25, 390 BP-related, 74 CC-related and 276 MF-related GO terms in FMG (Table S3). Interestingly, we found that the identified DEGs in two sweet potato varieties under salt stress were mainly distributed in \"biological processes (BP)\" and \"cell components (CC)\" among the top 50 most enriched GO terms (Fig S3). We also found that the DEGs in two sweet potato varieties under salt stress were mainly distributed in \"biological processes (BP)\" among the top 20 most enriched GO terms (Fig. 5 ). The top 20 GO terms of DEGs of two sweet potato varieties were compared. Only four GO terms were overlap (Fig. 5 ). The GO terms enrichment of DEGs from different sweet potato varieties were significantly different. DEGs were enriched in different pathways between YS25 and FMG In order to further understand the biological function of the identified DEGs in response to salt stress, we conducted a KEGG pathway enrichment analysis of DEGs. A total number of 126 pathways were identified in YS25 leaves after the salt treatment (Table S4). A total number of 130 pathways were identified in FMG leaves after the salt treatment (Table S4). Ten pathways in top 20 KEGG pathways, including “Zeatin biosynthesis”, “Starch and sucrose metabolism”, “Galactose metabolism”, “Nitrogen metabolism”, “Flavonoid biosynthesis”, “Carotenoid biosynthesis”, “Folate biosynthesis”, “ABC transporters”, “Phenylpropanoid biosynthesis” and “Glycosphingolipid biosynthesis - globo and isoglobo series” were identified in FMG leaves after the salt treatment (Fig. 6 ). Ten pathways in top 20 KEGG pathways, including “Ribosome”, “Glycolysis / Gluconeogenesis”, “Glycine, serine and threonine metabolism”, “Monoterpenoid biosynthesis”, “Citrate cycle (TCA cycle)”, “Sesquiterpenoid and triterpenoid biosynthesis”, “Glucosinolate biosynthesis”, “Alanine, aspartate and glutamate metabolism”, “Porphyrin and chlorophyll metabolism” and “Steroid biosynthesis” were identified in YS25 leaves after the salt treatment (Fig. 6 ). Ten pathways in top 20 KEGG pathways, including “Photosynthesis”, “Photosynthesis - antenna proteins”, “Glyoxylate and dicarboxylate metabolism”, “Carbon fixation in photosynthetic organisms”, “Pentose phosphate pathway”, “Vitamin B6 metabolism”, “Anthocyanin biosynthesis”, “Fructose and mannose metabolism”, “Peroxisome” and “Plant hormone signal transduction”, were both identified in YS25 and FMG leaves after the salt treatment (Fig. 6 ). Genes in the peroxisome pathway were differentially expressed in YS25 and FMG Our previous experimental results showed that the activity of peroxidase in FMG was higher than YS25 (Fig. 3 D, E, F). The peroxisome pathway was one of the common pathways for the enrichment of DEGs in FMG and YS25 after salt stress (Fig. 6 ). We also compared the expression of DEGs involved in the peroxisome pathway. A distinct intervarietal specific expression pattern was observed (Fig. 7 A, B, C, D). In YS25, 2 SOD genes, 46 POD genes, 21 GST genes and 13 GPX genes were up-regulated by salt stress (Fig. 7 A, B, C, D). However, in FMG, three SOD genes, 60 POD genes, 37 GST genes and 16 GPX genes were up-regulated (Fig. 7 A, B, C, D). In the peroxisome pathway, the number of up-regulated DEGs in FMG were higher than YS25, and the up-regulated multiple of DEGs were also higher than YS25 (Fig. 7 A, B, C, D). Genes in the key salt response pathways were differentially expressed in YS25 and FMG We also screened several critical pathways in FMG, including “Zeatin biosynthesis”, “Starch and sucrose metabolism”, “Galactose metabolism”, “Nitrogen metabolism”, “Flavonoid biosynthesis” (Fig. 6 ). In Zeatin biosynthesis pathway, there are 10 up-regulated DEGs in YS25 and 9 up-regulated DEGs in FMG, respectively (Fig. 8 A). In Starch and sucrose metabolism pathway, there are 27 up-regulated DEGs in YS25 and 26 up-regulated DEGs in FMG, respectively (Fig. 8 B). In Galactose metabolism pathway, there are up-regulated 26 DEGs in YS25 and 30 up-regulated DEGs in FMG, respectively (Fig. 8 C). In Nitrogen metabolism pathway, there are 9 up-regulated DEGs in YS25 and 9 up-regulated DEGs in FMG, respectively (Fig. 8 D). In Flavonoid biosynthesis pathway, there are 27 up-regulated DEGs in YS25 and 26 up-regulated DEGs in FMG, respectively (Fig. 8 E). Comparing the DEGs heatmaps of these five pathways in YS25 and FMG revealed that the gene expression levels were much higher in FMG than YS25 without treatment (Fig. 8 A, B, C, D, E). After salt stress treatment, there were no significant difference in the number of up-regulated ddegs between the two varieties, but the change ratio of up-regulated DEGs in FMG was higher than YS25 (Fig. 8 A, B, C, D, E). Physiological changes and key salt related gene expression were further verified in the sweet potato varieties of XGH and QT To verify the physiological responses in other sweet potato varieties to salt stress, We selected XGH and QT sweet potato varieties similar to YS25 and FMG (Fig S4), respectively. 2-week-old XGH and QT plants were treated with 0 or 300 mM NaCl for 6 days, respectively (Fig S5). After 4 days of salt treatment, XGH plants showed a leaf dechlorosis phenotype, while QT plants grew with green leaves. After 6 days, YS25 plants died, while FMG plants remained alive (Fig S5). After 4 days of salt treatment, the chlorophyll content in XGH and QT were decreased significantly, but the chlorophyll content in QT was less affected by salt stress than XGH (Fig S6A, B). To understand the effects of salt stress on ion accumulation in different sweet potato varieties, we investigated the content of K + , Na + and the K + / Na + ratio in the leaves of 2-week-old XGH and QT plants treated with 0 and 300 mM NaCl for 4 days (Fig S6C, D, E). Under normal conditions, the K + and Na + contents in XGH leaves was lower than that of QT leaves (Fig S6C, D). The K + / Na + ratio in QT leaves was higher than that of XGH in normal conditions (Fig S6E). After salt treatment, salt stress induced K + and Na + accumulation in XGH and QT leaves (Fig S6C, D). Under salt stress treatment, more K + and Na + contents were accumulated in XGH leaves than QT (Fig S6C, D). There was no difference in the K + / Na + ratio between XGH and QT after salt stress treatment (Fig S6E). To confirm that the antioxidant defense systems in other sweet potato varieties were also play an important role, we examined the antioxidant defense system between the two other varieties. When NaCl treatment was compared with CK treatment, the MDA content was increased in YS25 and FMG leaves (Fig S7). The increased MDA level in YS25 was significantly higher than that in FMG (Fig S7A). NaCl treatment significantly increased the H 2 O 2 contents in YS25 and FMG leaves, respectively, compared to CK treatment (Fig S7B). Under salt stress, the variation trend of soluble sugar was the same as that of malondialdehyde (Fig S7C). Under salt stress treatment, the change trend of antioxidant enzyme activity was the same in the two sweet potato varieties, and the antioxidant enzyme activities of SOD, CAT and POD were increased to different degrees (Fig S7D, E, F). SOD, CAT and POD activities increased significantly in FMG leaves under salt stress compared with YS25 (Fig S7D, E, F). To verify the candidate genes involved in the regulation of salt stress response, 24 up-regulated genes were selected for qRT-PCR analysis in different sweet potato cultivars (Fig. 9 A, B, C, D, E, F, G). Most of the selected DEGs were expressed higher in QT than in XHG (Fig. 9 A, B, C, D, E, F, G). Discussion Sweet potato is a food crop with high economic value in China (Zhang et al., 2017; Yu et al., 2015; Meng et al., 2020). Sweet potato is a salt sensitive plant (Yu et al., 2015). Mining and identifying salt tolerant genes of sweet potato is beneficial to improve salt tolerance of sweet potato through biotechnology breeding. the tolerance of different varieties to salt stress is significantly different. Previous transcriptome studies related to salt stress in sweet potato were few, and the results were inconsistent (Zhang et al., 2017; Meng et al., 2020). This indicated that there were differences in salt stress response between different types and different sources of sweet potato varieties. In this study, two sweet potato varieties, YS25 and FMG, were selected in the identification of salt tolerance of various sweet potato varieties. YS25 and FMG were two important sweet potato varieties in China because of their excellent taste. This study first assessed the resistance of two sweet potato varieties to salt stress. According to the analysis of leaf phenotype and physiological indexes under salt treatment, FMG was identified as a salt tolerant variety and YS25 as a salt sensitive variety (Fig. 1 , Fig. 2 , Fig. 3 ). Similar to previous studies, compared with salt sensitive varieties, salt tolerant varieties have higher antioxidant enzyme activity under salt stress, which makes the leaves of salt tolerant varieties less damaged by salt stress (Song et al., 2023; Shi and Gu, 2020; Farooq et al., 2024). In order to further understand the salt tolerance mechanisms of different sweet potato varieties, high-throughput transcriptome sequencing was performed on two salt stressed varieties (Fig. 4 ). Under salt stress, we identified 7370 differentially expressed genes in salt sensitive variety YS25 and 7068 differentially expressed genes in salt tolerant variety FMG (Fig. 4 ). In both salt tolerant and salt sensitive varieties, the number of downregulated genes exceeded the number of upregulated genes, which was consistent with previous studies (Zhang et al., 2017). We also compared the GO and KEGG enrichments of DEGs after salt treatment between YS25 and FMG (Fig. 5 ; Fig. 6 ; Table S4; Table S5). Interestingly, We found that DEGs of YS25 and FMG were more enriched in “biological processes (BP)” and “Molecular function (MF)” (Fig. 5 ; Table S4). We compared the GO terms of the top 50 most enriched DEGs in the two varieties under salt stress. The results showed that DEGs were mainly enriched in the GO terms belonging to BP and CC (Fig S3). The top 20 GO enrichment terms of DEGs from different sweet potato varieties were significantly different (Fig. 5 ). Previous studies on the transcriptome of salt stress had shown that the pathways involved in plant salt stress response are complex and diverse. The Nitrogen metabolism pathway, the plant hormone signal transduction pathway, the plant-pathogen interactions pathway, the starch and sucrose metabolism pathway, the biosynthesis of amino acids pathway, the flavonoid biosynthesis pathway and many other pathways played an important role in plant salt tolerance (Chen et ql., 2022; Gao et al., 2024; Shabala, 2013; Shi and Gu, 2020; Zhang et al., 2023). In our study, the results of KEGG pathways enrichment of DEGs in YS25 and FMG under salt stress were similar to previous studies (Fig. 6 ; Table S5). The top 20 KEGG pathways of DEGs in the two varieties were compared. Some important salt-stress-related KEGG pathways, including: the Pentose phosphate pathway pathway, the Anthocyanin biosynthesis pathway, the Fructose and mannose metabolis pathway, the Peroxisom pathway and the Plant hormone signal transduction pathway, were both in YS25 and FMG. In addition to the common salt-stress-related pathways in the top 20 KEGG pathways, salt sensitive varieties YS25 and salt tolerant varieties FMG had different KEGG pathways to cope with salt stress (Fig. 6 ; Table S5). The KEGG pathways identified in FMG, including: the Zeatin biosynthesis pathway, the Starch and sucrose metabolis pathway, the Galactose metabolis pathway, the Nitrogen metabolis pathway, the Flavonoid biosynthesis pathway, the Carotenoid biosynthesis pathway, the Folate biosynthesis pathway, the ABC transporters pathway, the Phenylpropanoid biosynthesi pathway and the Glycosphingolipid biosynthesis-globo and isoglobo series pathway were likely to play an important role in salt stress response (Fig. 6 ; Table S5). We compared the expression of DEGs in the important pathways of salt stress response by heatmap (Fig. 7 A, B, C, D; Fig. 8 A, B, C, D, E). We found that the expression of some key genes in these important salt stress response pathways was significantly up-regulated in the salt tolerant variety FMG (Fig. 7 A, B, C, D; Fig. 8 A, B, C, D, E). We identified another two varieties in the salt tolerance screening of different sweet potato varieties, salt sensitive variety XGH and salt tolerant variety QT. These two varieties are similar to YS25 and FMG not only in plant phenotype, but also in salt stress response (Fig S4; Fig S5). Comparative transcriptomic analysis revealed candidate genes related to anthocyanin biosynthesis in \"red Bartlett\" pear ( Pyrus communis L.) and validated these candidate genes in another variety (Dai et al., 2022). In our study, we also validated these candidate genes associated with salt stress response in other sweet potato varieties. Similar to previous studies, candidate genes were also involved in the salt stress response of salt tolerant sweet potato varieties with similar phenotypes (Fig. 9 ). The possible functions of these salt response-related genes need to be evaluated in detail in future. Conclusions The response of different sweet potato varieties to salt stress was analyzed. DEGs induced by salt stress in salt sensitive variety YS25 and salt tolerant variety FMG were identified. Significant differences were observed in GO and KEGG enrichment pathways of DEGs in between YS25 and FMG under salt stress condition. DEGs in the salt tolerant variety FMG were enriched in salt stress response pathways, such as the zeatin biosynthesis pathway, the starch and sucrose metabolis pathway, the galactose metabolis pathway, the nitrogen metabolis pathway and the flavonoid biosynthesis pathway. Salt tolerant candidate genes also showed the same response to salt stress in XGH and QT. Our results will help to deepen the understanding of the mechanism of salt tolerance in sweet potato and provide potential genetic resources for the genetic selection and breeding of new sweet potato varieties. Declarations Funding This work has been jointly supported by the following grants: the Natural Science Foundation of Shandong Province, China (ZR2024QC076, ZR2025QC352); the Innovation Project of Shandong Academy of Agricultural Sciences, China (CXGC2025B05); the Taishan Scholars Program (tsqn202312290); the National Natural Science Foundation of China (32071733, 32371915); the Sericultural Industry Technical System of Shandong Province (grant no. SDAIT-18-09). Conflict of Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Data availability All raw reads were deposited in the Sequence Read Archive (SRA) database in NCBI with accession number PRJNA1242390. Author contributions Rao Fu, Ruxia Li and Hongxia Zhang conceived and designed the experiments; Haiyang Zhang, Meng Li, Junlin Li, Dongyang Li, Chuanjie Chen, Yingyu Gu, Chi Zhang and Xiaoyan Liang performed the experiments and data analysis. Haiyang Zhang, Rao Fu, Ruxia Li and Hongxia Zhang wrote and revised the manuscript. All authors have read and approved the paper. References Adu Donyina G, Szarvas A, Opoku VA, Miko E, Tar M, Czóbel S, Monostori T (2025) Enhancing sweet potato production: a comprehensive analysis of the role of auxins and cytokinins in micropropagation. Planta, 261(4), 74. doi: 10.1007/s00425-025-04650-z Chen CX, Shang XL, Sun MY, Tang SY, Khan A, Zhang D, Yan HD, Jiang YX, Yu FF, Wu YR, Xie Q (2022) Comparative Transcriptome Analysis of Two Sweet Sorghum Genotypes with Different Salt Tolerance Abilities to Reveal the Mechanism of Salt Tolerance. Int J Mol Sci, 23, 2272. https://doi.org/10.3390/ijms23042272 Cui XY, Chen JM, Li S, Shao A, Fu JM (2025). Growth and physiological characteristics of forage bermudagrass in response to salt stress. BMC plant biology, 25(1), 269. https://doi.org/10.1186/s12870-025-06281-8 Dai XN, Li QY, Jiang FD, Song ZZ, Tang XL, Su SQ, Yao RT, Yang HY, Yang YQ, Zhang HX, Li JZ (2022) Transcriptome analysis of branches reveals candidate genes involved in anthocyanin biosynthesis of ‘Red Bartlett’ pear ( Pyrus communis L.). Scientia Horticulturae, 305. https://doi.org/10.1016/j.scienta.2022.111392. Farooq MA, Zeeshan Ul Haq M, Zhang L,Wu S, Mushtaq N, Tahir H, Wang Z (2024) Transcriptomic Insights into Salt Stress Response in Two Pepper Species: The Role of MAPK and Plant Hormone Signaling Pathways. Int J Mol Sci, 25, 9355. https://doi.org/10.3390/ ijms25179355 Flowers TJ, Colmer TD (2008) Salinity tolerance in halophytes. New Phytol 179, 945–963. https://doi.org/10.1111/j.1469-8137.2008.02531.x Gao QC, Yu RN, Ma XS, Wuriyanghan H, Yan F (2024) Transcriptome Analysis for Salt-Responsive Genes in Two Different Alfalfa ( Medicago sativa L.) Cultivars and Functional Analysis of MsHPCA1 . Plants, 13, 1073. https://doi.org/10.3390/ plants1308107C Hu YF, ZhaoHY, Xue LY, Nie N, Zhang H, Zhao N, He SZ, Liu QC, Gao SP, Zhai H (2024) IbMYC2 Contributes to Salt and Drought Stress Tolerance via Modulating Anthocyanin Accumulation and ROS-Scavenging System in Sweet Potato. Int J Mol Sci, 25, 2096. https://doi.org/10.3390/ijms25042096 Jin R, Kim BH, Ji CY, Kim HS, Li HM, Ma DF, Kwak SS (2017) Overexpressing IbCBF3 increases low temperature and drought stress tolerance in transgenic sweet potato. Plant Physiol Biochem, 118:45-54. https://doi.org/10.1016/j.plaphy.2017.06.002 Kang C, Zhai H, He SZ, Zhao N, Liu QC (2019) A novel sweet potato bZIP transcription factor gene, IbbZIP1 , is involved in salt and drought tolerance in transgenic Arabidopsis. Plant Cell Rep, 38, 1373–1382. https://doi.org/10.1007/s00299-019-02441-x Li H, Liu L, Kong XH, Wang XW, Si AJ, Zhao FX, Huang Q, Yu Y, Chen ZW (2025) Time-Course Transcriptomics Analysis Reveals Molecular Mechanisms of Salt-Tolerant and Salt-Sensitive Cotton Cultivars in Response to Salt Stress. Int J Mol Sci, 26, 329. https://doi.org/ 10.3390/ijms26010329 Li N, Zhang ZH, Chen ZJ, Cao BL, Xu K (2021) Comparative Transcriptome Analysis of Two Contrasting Chinese Cabbage ( Brassica rapa L.) Genotypes Reveals That Ion Homeostasis Is a Crucial Biological Pathway Involved in the Rapid Adaptive Response to Salt Stress. Front Plant Sci, 12:683891. https://doi.org/10.3389/fpls.2021.683891 Li RX, Fu R, Li M, Song YJ, Li JL, Chen CJ, Gu YY, Liang XY, Nie WJ, Ma L, Wang XY, Zhang HY, Zhang HX (2023) Transcriptome profiling reveals multiple regulatory pathways of Tamarix chinensis in response to salt stress. Plant Cell Rep 42, 1809–1824. https://doi.org/10.1007/s00299-023-03067-w Lin CC, Zheng SS, Liu K, Yu R, Guan PY, Hu BG, Jiang LL, Su MY, Hu GD, Chen QS, Zhang X (2025) Elucidating the molecular basis of salt tolerance in potatoes through miRNA expression and phenotypic analysis. Sci Rep 15, 2635. https://doi.org/10.1038/s41598-025-86276-5 Liu EL, Li ZQ, Luo ZQ, XuLL, Jin P, Ji S, Zhou GH,Wang ZY, Zhou ZL, Zhang H (2023) Genome-Wide Identification of DUF668 Gene Family and Expression Analysis under Drought and Salt Stresses in Sweet Potato [ Ipomoea batatas (L.) Lam]. Genes, 14, 217. https:// doi.org/10.3390/genes14010217 Luo Y, Reid R, Freese D, Li CB, Watkins J, Shi HZ, Zhang HY, Loraine A, Song BH (2017) Salt tolerance response revealed by RNA-Seq in a diploid halophytic wild relative of sweet potato. Sci Rep, 7, 9624. https://doi.org/10.1038/s41598-017-09241-x Mansour MMF, Emam MM, Salama KHA, Morsy AA (2021) Sorghum under saline conditions: Responses, tolerance mechanisms, and management strategies. Planta, 254, 24. https://doi.org/10.1007/s00425-021-03671-8 Meng XQ, Liu SY, Zhang CB, He JN, Ma DF, Wang X, Dong TT, Guo F, Cai J, Long TD, Li ZY, Zhu MK (2023) The unique sweet potato NAC transcription factor IbNAC3 modulates combined salt and drought stresses. Plant Physiol, 2;191(1):747-771. https://doi.org/10.1093/plphys/kiac508 Muchate NS, Nikalje GC, Rajurkar NS, Suprasanna P, Nikam TD (2016) Plant Salt Stress: Adaptive Responses, Tolerance Mechanism and Bioengineering for Salt Tolerance. Bot Rev, 82, 371–406. https://doi.org/10.1007/s12229-016-9173-y Munns R, Tester M (2008) Mechanisms of salinity tolerance. Annu Rev Plant Biol, 59 (1): 651-681. https://doi.org/10.1146/annurev.arplant.59.032607.092911 Ouertani RN, Arasappan D, Abid G, Ben Chikha M, Jardak R, Mahmoudi H, Mejri S, Ghorbel A, Ruhlman TA, Jansen RK (2021) Transcriptomic analysis of salt-stress-responsive genes in barley roots and leaves. Int J Mol Sci, 22, 8155. https://doi.org/10.3390/IJMS22158155 Rickman TE, Adams AK, Wadl PA, Yencho GC, Olukolu BA (2025). Genome-wide associations of sweet potato metabolites enhance genomic prediction and identify genes in metabolic and regulatory pathways. Scientific reports, 15(1), 9657. https://doi.org/10.1038/s41598-025-93415-5 Shabala S 2013 Learning from halophytes: physiological basis and strategies to improve abiotic stress tolerance in crops. Ann Bot, 112, 1209–1221. Shi PB, Gu MF (2020) Transcriptome analysis and differential gene expression profiling of two contrasting quinoa genotypes in response to salt stress. BMC Plant Biol, 20, 568. https://doi.org/10.1186/s12870-020-02753-1 Singh A, Roychoudhury A (2021) Gene regulation at transcriptional and post-transcriptional levels to combat salt stress in plants. Physiol Plant, 173, 1556–1572. https://doi.org/10.1111/ppl.13502 Song WX, Gao XQ, Li HP, Li SX, Wang J, Wang X, Wang TR, Ye YN, Hu PF, Li XH, Fu BZ (2023) Transcriptome analysis and physiological changes in the leaves of two Bromus inermis L. genotypes in response to salt stress. Front Plant Sci, 14:1313113. https://doi.org/10.3389/fpls.2023.1313113 Wang C, Lei J, Jin XJ, Chai SS, Jiao CH, Yang XS, Wang LJ (2024) A Sweet Potato MYB Transcription Factor IbMYB330 Enhances Tolerance to Drought and Salt Stress in Transgenic Tobacco. Genes, 2024, 15, 693. https://doi.org/10.3390/ genes15060693 Wang HY, Liu MY, Yang ST, Qiao S, Song W, Tan WF, Wang F (2025) Genome-wide analysis of PHT gene family and their role in LP and salt stress in sweet potato, Plant Physiol Biochem, 109642. https://doi.org/10.1016/j.plaphy.2025.109642 Wang M, Xia G (2018) The landscape of molecular mechanisms for salt tolerance in wheat. Crop J, 6, 42–47. https://doi.org/10.1016/j.cj.2017.09.002 Wu JY, Su YR, Pan ZY, Wang YM, Zhang YJ, Li LD, Jiang JH, Cao XY (2024) Identification of WRKY transcription factors in Ipomoea pes-caprae and functional role of IpWRKY16 in sweet potato salt stress response. BMC Plant Biol, 24, 1190. https://doi.org/10.1186/s12870-024-05928-2 Yang Z, Wang Y, Cheng QR, Zou X, Yang YX, Li P, Wang SJ, Su Y, Yang DJ, Kim HS, Jia XY, Li LZ, Kwak SS, Wang WB (2024) Overexpression of sweet potato glutamylcysteine synthetase (IbGCS) in Arabidopsis confers tolerance to drought and salt stresses. J Plant Res, 137, 669–683. https://doi.org/10.1007/s10265-024-01548-x Yu YC, Xu T, Li X, Tang J, Ma DF, Li ZY, Sun J (2015) NaCl-induced changes of ion homeostasis and nitrogen metabolism in two sweet potato ( Ipomoea batatas L.). nvironmental and Experimental Botany, 23-36, 0098-8472, https://doi.org/10.1016/j.envexpbot.2015.12.006. Zelm van E, Zhang Y, Testerink C (2020) Salt tolerance mechanisms of plants. Annu Rev Plant Biol 29, 71:403-433. https://doi.org/10.1146/annurev-arplant-050718-100005 Zhang C, Chen B, Zhang P, Han Q, Zhao G, Zhao F (2023) Comparative Transcriptome Analysis Reveals the Underlying Response Mechanism to Salt Stress in Maize Seedling Roots. Metabolites, 13, 1155. https://doi.org/10.3390/metabo13111155 Zhang F, Zhu GZ, Du L, Shang XG, Cheng CZ, Yang B, Hu Y, Cai CP, Guo WZ (2016) Genetic regulation of salt stress tolerance revealed by RNA-Seq in cotton diploid wild species, Gossypium davidsonii. Sci Rep, 6, 20582. https://doi.org/10.1038/s41598-019-45848-y Zhang H, Zhang Q, Zhai H, Li Y, Wang XF, Liu QC, He SZ (2017) Transcript profile analysis reveals important roles of jasmonic acid signalling pathway in the response of sweet potato to salt stress. Sci Rep, 7, 40819. https://doi.org/10.1038/srep40819. Zhao HY, Zhao HQ, Hu YF, Zhang SS, He SZ, Zhang H, Zhao N, Liu QC, Gao SP, Zhai H (2022) Expression of the Sweet Potato MYB Transcription Factor IbMYB48 Confers Salt and Drought Tolerance in Arabidopsis. Genes, 13, 1883. https://doi.org/10.3390/genes13101883 Zhao SS, Zhang QK, Liu MY, Zhou HP, Ma CL, Wang PP (2021) Regulation of Plant Responses to Salt Stress. Int J Mol Sci, 22, 4609. https://doi.org/10.3390/ijms22094609 Zhu JK (2016) Abiotic stress signaling and responses in plants. Cell, 167, 313–324. doi: 10.1016/j.cell.2016.08.029 Additional Declarations No competing interests reported. Supplementary Files Supplementarydata.rar Supplementary materials Table S1. Primer sequences used in this study. Table S2. Summary of the data quality of RNA-seq. Table S3. Information of the DEGs identified in YS25 and FMG after the salt stress treatment. Table S4. GO enrichment analysis of the DEGs. Table S5. KEGG pathway enrichment analysis of the DEGs. Fig. S1. The fruit phenotypes of YS25 and FMG. Fig. S2. qRT-PCR validation of RNA-seq data. Eight DEGs in YS25 and FMG were randomly selected and their expressions were confirmed with qRT-PCR. White columns stand for the changes of transcript abundance of the selected DEGs obtained from RNA-seq data. Gray bars stand for the relative expression levels of these DEGs determined by qRT-PCR. Error bars indicate the standard deviation with three biological replicates. Fig. S3. Histograms showing the top 50 GO terms of the DEGs in YS25 and FMG plants treated with 0 and 300 mM NaCl for 2 days . Fig. S4. The fruit phenotypes of XGH and QT. Fig. S5. The phenotype of XGH and QT plants after salt stress. Two-weeks-old sweet potato seedlings at the same size and growth status were treated with 0 mM and 300 mM NaCl for 6 days. Scale bar = 10 cm. Fig. S6. Determination of chlorophyll content, Na + content and K + content in the leaves of XGH and QT plants. The contents of chlorophyll content, Na + and K + in the leaves of sweet potato plants treated with 0 and 300 mM NaCl for 4 days were assessed. (A) The contents of chlorophyll content. (B) The reduction of rate in chlorophyll content. (C) K + contents. (D) Na + contents. (E) K + / Na + ratios. Values are the mean ± SD from three independent experiments. Values are the mean ± SD from three independent experiments. Values significantly different analyzed with Duncan’s multiple comparison tests are labeled with different letters ( P < 0.05; n = 3). Fig. S7. Determination of malondialdehyde, hydrogen peroxide, soluble sugar and peroxidase activity in XGH and QT leaves. The contents of MDA, H 2 O 2 , soluble sugar and peroxidase activity in sweet potato leaves treated with 0 and 300 mM NaCl for 4 days were determined. (A) The content of MDA. (B) The content of H 2 O 2 . (C) The content of Soluble sugar. (D) SOD activity. (E) POD activity. (F) CAT activity. Values are the mean ± SD from three independent experiments. Values are the mean of three independent experiments ±SD. Duncan multiple comparison test was used to analyze the values with significant differences and marked with different letters (P < 0.05; N = 3). Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 28 Jan, 2026 Reviews received at journal 28 Jan, 2026 Reviews received at journal 28 Jan, 2026 Reviews received at journal 20 Jan, 2026 Reviews received at journal 20 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers agreed at journal 14 Jan, 2026 Reviewers invited by journal 14 Jan, 2026 Editor assigned by journal 09 Jan, 2026 Submission checks completed at journal 09 Jan, 2026 First submitted to journal 05 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-8517679\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":574601440,\"identity\":\"365b2842-c85a-42b5-bd96-9ecd8d6ba7fd\",\"order_by\":0,\"name\":\"Haiyang Zhang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Haiyang\",\"middleName\":\"\",\"lastName\":\"Zhang\",\"suffix\":\"\"},{\"id\":574601441,\"identity\":\"741ae12a-9089-48f7-b8e3-9f1d49dc8537\",\"order_by\":1,\"name\":\"Meng Li\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Meng\",\"middleName\":\"\",\"lastName\":\"Li\",\"suffix\":\"\"},{\"id\":574601443,\"identity\":\"13044253-646d-4fa8-a0e5-c2811e147cb3\",\"order_by\":2,\"name\":\"Junlin Li\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Junlin\",\"middleName\":\"\",\"lastName\":\"Li\",\"suffix\":\"\"},{\"id\":574601446,\"identity\":\"1747c994-3417-4147-8ef8-22f874521f59\",\"order_by\":3,\"name\":\"Dongyang Li\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Dongyang\",\"middleName\":\"\",\"lastName\":\"Li\",\"suffix\":\"\"},{\"id\":574601449,\"identity\":\"0bf75247-a765-482f-aa91-7c81fb9190b0\",\"order_by\":4,\"name\":\"Chuanjie Chen\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Chuanjie\",\"middleName\":\"\",\"lastName\":\"Chen\",\"suffix\":\"\"},{\"id\":574601455,\"identity\":\"883d8f42-98b6-462d-b5bf-09b1f4e6e563\",\"order_by\":5,\"name\":\"Yinyu Gu\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Yinyu\",\"middleName\":\"\",\"lastName\":\"Gu\",\"suffix\":\"\"},{\"id\":574601458,\"identity\":\"489ff315-d125-4b70-a390-640439532238\",\"order_by\":6,\"name\":\"Chi Zhang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Chi\",\"middleName\":\"\",\"lastName\":\"Zhang\",\"suffix\":\"\"},{\"id\":574601460,\"identity\":\"9a33b406-db8a-4e59-9c58-f1ab81b3a887\",\"order_by\":7,\"name\":\"Xiaoyan Liang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Xiaoyan\",\"middleName\":\"\",\"lastName\":\"Liang\",\"suffix\":\"\"},{\"id\":574601461,\"identity\":\"9f03b1ea-4f22-4f2b-9797-10a7ab459668\",\"order_by\":8,\"name\":\"Rao Fu\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Rao\",\"middleName\":\"\",\"lastName\":\"Fu\",\"suffix\":\"\"},{\"id\":574601471,\"identity\":\"50bd54cc-16fb-46c7-a254-d2cd4e6716d7\",\"order_by\":9,\"name\":\"Ruxia Li\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Ruxia\",\"middleName\":\"\",\"lastName\":\"Li\",\"suffix\":\"\"},{\"id\":574601476,\"identity\":\"d615b0be-6491-4bf6-9064-58d52ab4d67a\",\"order_by\":10,\"name\":\"Hongxia Zhang\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzklEQVRIiWNgGAWjYBACAwYGNhAtx8DMQ6IWY9K1JDYwEKvFXCL92YOfO2rT57fzHv7AUGPHwD+7Ab8Wy54D6Ya9Z47nbjjMlybBcCyZQeLOAQIOO95wTIK37VjuBmYeM6AjDzAYSCQQ0HKYsU3yb9uxdPlmHuMPDP+I0XK8mU2at60mgeEwj4EEYxsxWs4cY5OWbTtgCPZLYl8yj8QNQlpupD+TfNtWJy/ff/bwhw/f7OT4ZxDQAgWHIRRQMbGxw1BHrMJRMApGwSgYiQAA5nY/Ls1ng2oAAAAASUVORK5CYII=\",\"orcid\":\"\",\"institution\":\"Shandong Institute of Sericulture\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Hongxia\",\"middleName\":\"\",\"lastName\":\"Zhang\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2026-01-05 06:38:50\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-8517679/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-8517679/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":100576943,\"identity\":\"511d862c-9e06-44ce-8061-40e563916da1\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:36\",\"extension\":\"doc\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":47348736,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"ManuscriptJan52026.doc\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/dfdef55b41a96e2df81ec039.doc\"},{\"id\":100576895,\"identity\":\"b360e4e4-47fe-4729-b390-5a023b48ce0a\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"json\",\"order_by\":10,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":11267,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"a2a0e529f6434c61a67ba67dd26de799.json\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/bc1164fdb2644a1f85ea74df.json\"},{\"id\":100576907,\"identity\":\"c684e67c-2380-4eea-803b-0f4a19a4d215\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"rar\",\"order_by\":11,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":11049290,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Supplementarydata.rar\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/fe4873baf3a93b0a86cd7484.rar\"},{\"id\":100576897,\"identity\":\"ca6671c4-3cf3-4377-ac02-9123e977d6d3\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"xml\",\"order_by\":12,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":95527,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"a2a0e529f6434c61a67ba67dd26de7991enriched.xml\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/286d9b1e06f373ca74d9b4d9.xml\"},{\"id\":100595994,\"identity\":\"067dc692-243d-4676-bd02-7ea8c263a49c\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:06\",\"extension\":\"jpg\",\"order_by\":13,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":1160053,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig1.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/6fbf019ecc41977682894699.jpg\"},{\"id\":100594991,\"identity\":\"5ab3c556-b47c-4be9-80f0-d47e418f1ff3\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:46:54\",\"extension\":\"jpg\",\"order_by\":14,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":4143732,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig2.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/31de258a2f3b9a48d8396223.jpg\"},{\"id\":100576904,\"identity\":\"19f5262d-bec9-44fd-8166-a93fe8bc10c2\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpg\",\"order_by\":15,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":3637229,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig3.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/93d9748273d9c2d8b4251748.jpg\"},{\"id\":100576896,\"identity\":\"f4c3cf37-461c-4c45-98ff-4dcafc17d68c\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpg\",\"order_by\":16,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":691050,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig4.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/96165f4a04b14c27e4465fef.jpg\"},{\"id\":100595585,\"identity\":\"d14ed047-a80c-41e7-a2b8-792e66774762\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:51\",\"extension\":\"jpg\",\"order_by\":17,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":2757914,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig5.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/5d5b1e1cb9ea8f06e494dd5d.jpg\"},{\"id\":100596098,\"identity\":\"061bd759-ecfb-412d-bfdc-f9a59c8b168d\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:51:23\",\"extension\":\"jpg\",\"order_by\":18,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":508964,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig6.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/3137047ff8df2f72318605d1.jpg\"},{\"id\":100595567,\"identity\":\"8d39a96f-310f-4199-993f-f951dc7c6aee\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:48\",\"extension\":\"jpg\",\"order_by\":19,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":13591205,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig7.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/f48d55a97651e48cfa034588.jpg\"},{\"id\":100576926,\"identity\":\"3e581e9a-6be9-4cf4-bd12-117585edc2ff\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpg\",\"order_by\":20,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":17242987,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig8.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/a1aeec704ad45f5302f9ae5f.jpg\"},{\"id\":100595632,\"identity\":\"67ffa343-f83e-4d93-b954-7b3aa358fc7e\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:58\",\"extension\":\"jpg\",\"order_by\":21,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":3017507,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig9.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/45e4ef89ce42a5d253f4949c.jpg\"},{\"id\":100576902,\"identity\":\"c8b49fb9-c5c7-4831-a39d-caca9b471a80\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpeg\",\"order_by\":22,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":1160053,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig1.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/6eec49085a9cefb41bef411e.jpeg\"},{\"id\":100576900,\"identity\":\"5a85cad3-6741-4c40-a4b2-81eb4a6000a3\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpeg\",\"order_by\":23,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":4143732,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig2.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/d8a399141053dec141b4141f.jpeg\"},{\"id\":100576918,\"identity\":\"20a23561-4762-4ca1-829d-e0538ecff83e\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpeg\",\"order_by\":24,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":3637229,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig3.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/335af5a133e2c965e28f08e3.jpeg\"},{\"id\":100595732,\"identity\":\"aec31287-8cb7-4b0c-8e1e-b53300d58956\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:49:17\",\"extension\":\"jpeg\",\"order_by\":25,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":529869,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"floatimage4.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/709cd6b5a2ee9557776089db.jpeg\"},{\"id\":100576915,\"identity\":\"f2c80ba9-af30-43fc-80f4-db1fff283403\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpeg\",\"order_by\":26,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":2757914,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig5.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/0c980d06624235e7930624f7.jpeg\"},{\"id\":100576911,\"identity\":\"52c5aad0-d463-448e-bcc0-3563d467632f\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpeg\",\"order_by\":27,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":509118,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"floatimage6.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/7f3405fdbfa26a1df77bba92.jpeg\"},{\"id\":100595841,\"identity\":\"310d26bb-a052-4aa0-9b3e-d58953c50557\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:49:31\",\"extension\":\"jpeg\",\"order_by\":28,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":13735233,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"floatimage7.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/31a5ad3b857868c19630a8a0.jpeg\"},{\"id\":100595152,\"identity\":\"e9246c7c-a547-40df-aecc-7f5d8be8a1db\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:47:42\",\"extension\":\"jpeg\",\"order_by\":29,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":17242987,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig8.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/5cbad256e85cdf6069aa89c8.jpeg\"},{\"id\":100596066,\"identity\":\"8b16ca80-171c-4e76-b518-a9be4395878b\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:37\",\"extension\":\"jpeg\",\"order_by\":30,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":3017507,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Fig9.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/f01b3deb1b028fb3e0088272.jpeg\"},{\"id\":100596007,\"identity\":\"dd501f3b-9955-44e9-ab1d-a1a76a7f6819\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:13\",\"extension\":\"png\",\"order_by\":31,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":439799,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/d714c1fba2ef174a0b34204d.png\"},{\"id\":100596063,\"identity\":\"713bc969-08e9-4971-a829-6d00fe552a15\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:34\",\"extension\":\"png\",\"order_by\":32,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":1267276,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/753ffc8174acd290918fce94.png\"},{\"id\":100576921,\"identity\":\"e2fafc06-c303-4ce5-bda5-690bf8e1af7e\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"png\",\"order_by\":33,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":916770,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/86b688805158018007a71146.png\"},{\"id\":100595587,\"identity\":\"31d0488e-ee49-4487-aa23-530f23a34d83\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:51\",\"extension\":\"png\",\"order_by\":34,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":89923,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig4.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/64d6a36c3e78be9e08567b1c.png\"},{\"id\":100595534,\"identity\":\"e65e9b95-7ee3-472b-8bad-67fbdb905d14\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:42\",\"extension\":\"png\",\"order_by\":35,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":365227,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig5.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/b98d3704581a71d048ed991e.png\"},{\"id\":100595566,\"identity\":\"703171ec-b7bf-4ac1-88aa-f1992cebfcb3\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:48\",\"extension\":\"png\",\"order_by\":36,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":76522,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig6.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/95cfa89214a3e68cc9745476.png\"},{\"id\":100595611,\"identity\":\"5c34510c-5d72-4edc-b9f5-20f9ec3b0410\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:55\",\"extension\":\"png\",\"order_by\":37,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":1592248,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig7.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/9ca74ca16b3439abd98266e5.png\"},{\"id\":100596065,\"identity\":\"539a9e11-9d72-4f61-9dfb-e1f20ebbb5b6\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:36\",\"extension\":\"png\",\"order_by\":38,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":2752203,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig8.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/83a1208c24b3f79eab73eb15.png\"},{\"id\":100595744,\"identity\":\"55207218-4a52-4a44-b14f-094a45fc1263\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:49:20\",\"extension\":\"png\",\"order_by\":39,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":868694,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"OnlineFig9.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/ebe84b6b6c4b81f1d4638b20.png\"},{\"id\":100576934,\"identity\":\"100fc61f-97f9-4cc5-8e8c-253c0bb66d7c\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"png\",\"order_by\":40,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":439799,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/71196ee2a2a72bd9806f3d43.png\"},{\"id\":100576931,\"identity\":\"f44749a5-675d-446d-9119-4997c7f39e35\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"png\",\"order_by\":41,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":1267276,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/e8953ee6253c75c0c63dc806.png\"},{\"id\":100595651,\"identity\":\"2ceaa42c-ea33-4048-9656-0f9f519af879\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:49:01\",\"extension\":\"png\",\"order_by\":42,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":916770,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/f6d61b0f66e1b9ea8f2bf24b.png\"},{\"id\":100576919,\"identity\":\"e338428e-2b53-4bdd-bf5c-d8d174b45fc1\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"png\",\"order_by\":43,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":111392,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage4.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/7609c2a5eaeeb4087afd2d7b.png\"},{\"id\":100576936,\"identity\":\"ece2800d-3957-4783-bef9-255e23779065\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"png\",\"order_by\":44,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":365227,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage5.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/4acfb80a3f57be1469fb190f.png\"},{\"id\":100596099,\"identity\":\"e4107610-e5ad-4afc-9b37-c84fcf94f074\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:51:25\",\"extension\":\"png\",\"order_by\":45,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":76304,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage6.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/783de104b9ba21c2405ce3c0.png\"},{\"id\":100596004,\"identity\":\"55c0739a-bd37-4490-b39e-869286e28073\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:12\",\"extension\":\"png\",\"order_by\":46,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":1582407,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage7.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/872602d652dbab570c419c83.png\"},{\"id\":100595954,\"identity\":\"eba28194-b5b3-4d3a-8215-014a5929de52\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:49:52\",\"extension\":\"png\",\"order_by\":47,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":2752203,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage8.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/2546afe70444a3e6d62b707c.png\"},{\"id\":100576938,\"identity\":\"5c3cff74-5ca7-4ebf-9ab5-4f87a5d5bb3b\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"png\",\"order_by\":48,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":868694,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Onlinefloatimage9.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/974977689b798513d8b491ce.png\"},{\"id\":100576928,\"identity\":\"18a70bec-5f70-4508-a22c-fc93c05b6b41\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"xml\",\"order_by\":49,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":92000,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"a2a0e529f6434c61a67ba67dd26de7991structuring.xml\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/a6069a0277dd86aacdefd19a.xml\"},{\"id\":100576932,\"identity\":\"289cd340-94bd-465e-a8ba-2f61c97907fd\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"html\",\"order_by\":50,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"acdc-reference\",\"size\":103203,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"earlyproof.html\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/7b27d715624d5abf1f030537.html\"},{\"id\":100576891,\"identity\":\"2bfee125-30c3-486f-9ce7-e72afa701551\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpg\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1160053,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eThe phenotype of YS25 and FMG plants after salt stress. Two-week-old sweet potato seedlings at the same size and growth status were treated with 0 mM and 300 mM NaCl for 6 days. Scale bar = 10 cm.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig1.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/acf3836b5f6c5f4e5dc33849.jpg\"},{\"id\":100576890,\"identity\":\"09c58611-7eba-434b-89a1-2c42d869d687\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpg\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":4143732,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eDetermination of chlorophyll content, Na\\u003csup\\u003e+\\u003c/sup\\u003e content and K\\u003csup\\u003e+\\u003c/sup\\u003e content in the leaves of YS25 and FMG plants. The contents of chlorophyll content, Na\\u003csup\\u003e+\\u003c/sup\\u003e and K\\u003csup\\u003e+\\u003c/sup\\u003e in the leaves of sweet potato plants treated with 0 and 300 mM NaCl for 4 days were assessed. (A) The contents of chlorophyll content. (B) The reduction of rate in chlorophyll content. (C) K\\u003csup\\u003e+\\u003c/sup\\u003e contents. (D) Na\\u003csup\\u003e+\\u003c/sup\\u003e contents. (E) K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratios. Values are the mean ± SD from three independent experiments. Values significantly different analyzed with Duncan’s multiple comparison tests are labeled with different letters (P \\u0026lt; 0.05; n = 3).\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig2.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/48af851ee7f0976e7f99ed77.jpg\"},{\"id\":100595392,\"identity\":\"e6864ad0-709f-4da7-817c-0015fd2f43e9\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:22\",\"extension\":\"jpg\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":3637229,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eDetermination of malondialdehyde, hydrogen peroxide, soluble sugar and peroxidase activity in YS25 and FMG leaves. The contents of MDA, H2O2, soluble sugar and peroxidase activity in sweet potato leaves treated with 0 and 300 mM NaCl for 4 days were determined. (A) The content of MDA. (B) The content of H2O2. (C) The content of Soluble sugar. (D) SOD activity. (E) POD activity. (F) CAT activity. Values are the mean of three independent experiments ±SD. Duncan multiple comparison test was used to analyze the values with significant differences and marked with different letters (P \\u0026lt; 0.05; N = 3).\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig3.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/304079ab4c40c9d2fefaa222.jpg\"},{\"id\":100596067,\"identity\":\"f88b4353-0247-4b96-83fe-5edf4859e8b0\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:38\",\"extension\":\"jpg\",\"order_by\":4,\"title\":\"Figure 4\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":691050,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eDifferentially expressed genes (DEGs) in YS25 and FMG plants treated with 0 and 300 mM NaCl for 2 days. (A) Venn diagrams showing the numbers of DEGs in YS25 and FMG plants. (B) Up-regulated and down-regulated DEGs in YS25 and FMG plants.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig4.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/1aa489a833707d99c9bc1da4.jpg\"},{\"id\":100576894,\"identity\":\"89cc316b-551a-4b2c-a969-c61cb477ca88\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpg\",\"order_by\":5,\"title\":\"Figure 5\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":2757914,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eHistograms showing the top 20 GO terms of the DEGs in YS25 and FMG plants treated with 0 and 300 mM NaCl for 2 days.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig5.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/44db463c825925889c318d95.jpg\"},{\"id\":100595339,\"identity\":\"03bbfdfd-43a1-4a48-8339-2223c9708775\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:15\",\"extension\":\"jpg\",\"order_by\":6,\"title\":\"Figure 6\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":508964,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eThe scatter plots of Top 20 KEGG pathway analysis in YS25 and FMG plants treated with 0 and 300 mM NaCl for 2 days. The circle size represents gene number in the pathways, and the circle color reflects the q-value. The colors from red to blue represent the significance of enrichment levels.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig6.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/0409cdf26d8e0b6f128fe8d9.jpg\"},{\"id\":100595843,\"identity\":\"e3cba8a8-a144-4f9b-b5b5-2c72b65c68c0\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:49:32\",\"extension\":\"jpg\",\"order_by\":7,\"title\":\"Figure 7\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":13591205,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eHeatmaps showing the DEGs in peroxisome pathway. (a) SOD releated DEGs. (b) POD releated DEGs.. (c) GST releated DEGs.. (d) GPX releated DEGs.. The color bar indicates the expression values calculated as RPKM (reads per kilobase per million mapped reads) using the TMM algorithm in EdgeR software.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig7.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/d8a68bad37ec19ddf3c51ad3.jpg\"},{\"id\":100576910,\"identity\":\"bd08a947-8ee3-4209-bbe6-6f798e553677\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 10:33:35\",\"extension\":\"jpg\",\"order_by\":8,\"title\":\"Figure 8\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":17242987,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eHeatmaps showing the DEGs in the Zeatin biosynthesis pathway, the Starch and sucrose metabolis pathway, the Galactose metabolis pathway, the Nitrogen metabolis pathway and the Flavonoid biosynthesis pathway.. (A) Zeatin biosynthesis pathway. (B) Starch and sucrose metabolis pathway. (C) Galactose metabolis pathway. (D) Nitrogen metabolis pathway. (E) Flavonoid biosynthesis pathway.. The color bar indicates the expression values calculated as RPKM (reads per kilobase per million mapped reads) using the TMM algorithm in EdgeR software.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig8.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/f08f1e966e325b3169ecaf4e.jpg\"},{\"id\":100595990,\"identity\":\"fe35cafd-7034-498f-a53b-db3d4b0562d7\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:50:05\",\"extension\":\"jpg\",\"order_by\":9,\"title\":\"Figure 9\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":3017507,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eqRT-PCR validation of candidate genes in other sweet potato varieties. 24 DEGs in d ifferent pathways were selected and their expressions were confirmed with qRT-PCR. (A) Candidate genes in CAT pathway. (B) Candidate genes in SOD pathway. (C) Candidate genes in POD pathway. (D) Candidate genes in the Zeatin biosynthesis pathway. (E) Candidate genes in the Starch and sucrose metabolis pathway. (E) Candidate genes in the Galactose metabolis pathway. (F) Candidate genes in the Nitrogen metabolis pathway. (G) Candidate genes in the Flavonoid biosynthesis pathway. White columns stand for the changes of transcript abundance of the selected DEGs in XGH leaves after salt treatment. Gray bars stand for the relative expression levels of these DEGs in QT leaves after salt treatment. Error bars indicate the standard deviation with three biological replicates.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Fig9.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/6a3b44bbd11fa1bd6d1bc2a4.jpg\"},{\"id\":100803980,\"identity\":\"3face654-2953-4e6a-9397-b22955adbdc3\",\"added_by\":\"auto\",\"created_at\":\"2026-01-21 14:33:27\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":47685205,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/26038a84-eb60-4daf-a6be-c3be64d88edb.pdf\"},{\"id\":100595391,\"identity\":\"2c400469-6577-4c7d-ba5a-4f65a87ffedd\",\"added_by\":\"auto\",\"created_at\":\"2026-01-19 13:48:22\",\"extension\":\"rar\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":11049290,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003e\\u003cstrong\\u003eSupplementary materials\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable S1.\\u003c/strong\\u003e Primer sequences used in this study.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable S2.\\u003c/strong\\u003e Summary of the data quality of RNA-seq.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable S3.\\u003c/strong\\u003e Information of the DEGs identified in YS25 and FMG after the salt stress treatment.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable S4.\\u003c/strong\\u003e GO enrichment analysis of the DEGs.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable S5.\\u003c/strong\\u003e KEGG pathway enrichment analysis of the DEGs.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. S1. \\u003c/strong\\u003eThe fruit phenotypes of YS25 and FMG.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. S2.\\u003c/strong\\u003e \\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003eqRT-PCR validation of RNA-seq data. Eight DEGs in YS25 and FMG were randomly selected and their expressions were confirmed with qRT-PCR. White columns stand for the changes of transcript abundance of the selected DEGs obtained from RNA-seq data. Gray bars stand for the relative expression levels of these DEGs determined by qRT-PCR. Error bars indicate the standard deviation with three biological replicates.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. S3. \\u003c/strong\\u003eHistograms showing the top 50 GO terms of the DEGs in YS25 and FMG plants treated with 0 and 300 mM NaCl for 2 days\\u003cem\\u003e.\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. S4. \\u003c/strong\\u003eThe fruit phenotypes of XGH and QT.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. S5.\\u003c/strong\\u003e The phenotype of XGH and QT plants after salt stress. Two-weeks-old sweet potato seedlings at the same size and growth status were treated with 0 mM and 300 mM NaCl for 6 days. Scale bar = 10 cm.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. S6.\\u003c/strong\\u003e Determination of chlorophyll content, Na\\u003csup\\u003e+\\u003c/sup\\u003e content and K\\u003csup\\u003e+\\u003c/sup\\u003e content in the leaves of XGH and QT plants. The contents of chlorophyll content, Na\\u003csup\\u003e+\\u003c/sup\\u003e and K\\u003csup\\u003e+\\u003c/sup\\u003e in the leaves of sweet potato plants treated with 0 and 300 mM NaCl for 4 days were assessed. (A) The contents of chlorophyll content. (B) The reduction of rate in chlorophyll content. (C) K\\u003csup\\u003e+\\u003c/sup\\u003e contents. (D) Na\\u003csup\\u003e+\\u003c/sup\\u003e contents. (E) K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratios. Values are the mean ± SD from three independent experiments. Values are the mean ± SD from three independent experiments. Values significantly different analyzed with Duncan’s multiple comparison tests are labeled with different letters (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026lt; 0.05; n = 3).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. S7.\\u003c/strong\\u003e Determination of malondialdehyde, hydrogen peroxide, soluble sugar and peroxidase activity in XGH and QT leaves. The contents of MDA, H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e, soluble sugar and peroxidase activity in sweet potato leaves treated with 0 and 300 mM NaCl for 4 days were determined. (A) The content of MDA. (B) The content of H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e. (C) The content of Soluble sugar. (D) SOD activity. (E) POD activity. (F) CAT activity. Values are the mean ± SD from three independent experiments. Values are the mean of three independent experiments ±SD. Duncan multiple comparison test was used to analyze the values with significant differences and marked with different letters (P \\u0026lt; 0.05; N = 3).\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Supplementarydata.rar\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8517679/v1/3b3efd5291d2afb1a4534cc3.rar\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Transcriptome profiling comparison between the salt sensitive and tolerant cultivars of sweet potato reveals the key regulatory pathways in response to high salt stress\",\"fulltext\":[{\"header\":\"Key message\",\"content\":\"\\u003cp\\u003eKey pathways in different sweet potato varieties in response to salt stress identified through transcriptomic profiling.\\u003c/p\\u003e\"},{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003eSoil salinization is one of the common abiotic stresses seriously affecting agricultural productivity in the world (Li et al., 2025; Lin et al., 2025). Upon salt stress, the ability of plant roots to absorb nutrients and water decreased, leading to limited plant growth (Cui et al., 2025; Munns and Tester, 2008; Zhao et al., 2021). At the same time, the accumulation of sodium ions in plants changed the transcription levels of many genes involved in photosynthesis, ion balance, metabolism and synthesis (Mansour et al., 2021; Muchate et al., 2016; Singh et al., 2021; Zhang et al., 2016). The response of plants to salt stress is a complex and diverse tolerance mechanism formed by the activation of thousands of genes (Zelm et al., 2020; Zhu, 2006). Under salt stress condition, Na\\u003csup\\u003e+\\u003c/sup\\u003e was excreted and separated by plant ion transporters to maintain intracellular ion balance (Flowers and Colmer, 2008; Wang et al., 2018). The expression of a large number of peroxidase genes in the peroxidase pathway alleviated the damage of high levels of reactive oxygen species (ROS) induced by salt stress on plant DNAs, proteins and lipids (Li et al., 2023). Many Transcription factors (TFs), such as bZIP, MYB, WRKY and AP2/ERF, played an important role in regulating signal transduction and transcription of genes related to salt stress response (Meng et al., 2020).\\u003c/p\\u003e \\u003cp\\u003eSweet potato (\\u003cem\\u003eIpomoea batatas\\u003c/em\\u003e (L.) Lam.) is an important food crop (Adu et al., 2025; Rickman et al., 2025). Over the past 20 years, the production of sweet potato have increased significantly, and sweet potato have become the fifth most important crop, right after rice, wheat, maize and sorghum (Rickman et al., 2025). Sweet potato is a salt sensitive plant (Luo et al., 2017). The growth and yield of it were often affected under saline soil condition (Zhang et al., 2017). Therefore, it is of great significance to explore salt tolerant genes and understand their physiological and molecular mechanisms for the breeding of salt tolerant sweet potato varieties. To date, a great number of abiotic stress associated genes have been identified in sweet potato, and their functions in plants were studied (Hu et al., 2024; Liu et al., 2023; Meng et al., 2023; Wang et al., 2024; Wang et al., 2025; Wu et al., 2024; Yang et al., 2024). For example, sweet potato \\u003cem\\u003eIbGCS\\u003c/em\\u003e, \\u003cem\\u003eIbMYB48\\u003c/em\\u003e, \\u003cem\\u003eIbbZIP1\\u003c/em\\u003e improved the drought and salt stress resistance of transgenic plants (Kang et al., 2019; Yang et al., 2024; Zhao et al., 2022). \\u003cem\\u003eIbMYB330\\u003c/em\\u003e, a sweet potato MYB transcription factor, enhanced the tolerance of transgenic tobacco to drought and salt stress (Wang et al., 2024). Overexpression of \\u003cem\\u003eIbCBF3\\u003c/em\\u003e increased the tolerance of transgenic sweet potato to low temperature and drought stress (Rong et al., 2017).\\u003c/p\\u003e \\u003cp\\u003eTranscriptome sequencing technology has become one of the common techniques used to study how plants respond to abiotic stress (Ouertani et al., 2021). In \\u003cem\\u003eTaxus chinensis\\u003c/em\\u003e, transcriptome analysis showed that transcription factors, along with genes associated with oxidative stress, starch and sucrose metabolism, and ion homeostasis, played crucial roles in the response to salt stress (Li et al., 2023). The ability of plants to resist salinity stress differed both among different species and within the same species (Munns et al., 2008). A great significance of ion homeostasis in the rapid adaptive response to salt stress in two different varieties of Chinese cabbage was discovered through transcriptome comparison analyses (Li et al., 2021). In sweet potato, transcriptomic assays in the roots of the salt sensitive variety Lizixiang and the salt tolerant line ND98 indicated that the JA signalling was the important pathway in response to salt stress (Zhang et al., 2017). However, in two other sweet potato varieties, the salt tolerant cultivar Xushu 22 and the salt sensitive cultivar Xushu 32, genes related to ion accumulation, stress signalling, transcriptional regulation, plant hormone signalling and secondary metabolite accumulation played an important role in salt stress response (Meng et al., 2020).\\u003c/p\\u003e \\u003cp\\u003eIn this study, two salt sensitive cultivars, YS25 and XGH, and two salt tolerant cultivars, FMG and QT, were used to dissect the mechanism of how they respond differently to high salt stress. RNA-seq analysis identified the candidate genes and pathways involved in salt stress response, which laid a solid foundation for the future study on salt tolerance response in sweet potato.\\u003c/p\\u003e\"},{\"header\":\"Materials and Methods\",\"content\":\"\\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003ePlant materials and salt treatments\\u003c/h2\\u003e \\u003cp\\u003eThe root tubes and shoot branches of \\\"Yan Shu 25\\\" (designated as YS25), \\\"Feng Mi Guan\\\" (designated as FMG), \\\"Xi Gua Hong\\\" (designated as XGH) and \\\"Qing Tian\\\" (designated as QT) were taken from Gaoling Town, Muping District, Yantai City, Shandong Province, China. The branches of YS25, FMG, XGH and QT were planted in triangle flasks containing H\\u003csub\\u003e2\\u003c/sub\\u003eO, and cultured in plant growth chamber under a 14/10 h light/dark period with a 70\\u0026ndash;75% relative humidity at 24\\u0026deg;C. The culture solution was changed every 2 days. For salt resistance assays, two-week-old plantlets at the same size and growth status were treated with 0 mM, 100 mM, 200 mM, 300 mM and 400 mM NaCl. The critical concentration for 2-week-old sweet potato seedlings was 300 mM NaCl. The treatment culture solution was changed every 2 days. For RNA-seq, leaves from at least 9 plants of each group after 2 days treatment were harvested and stored at -80\\u0026deg;C. Three biological replicates were performed.\\u003c/p\\u003e \\u003c/div\\u003e\\n\\u003ch3\\u003eDetermination of physiological indexes\\u003c/h3\\u003e\\n\\u003cp\\u003eFor the determination of ion content and peroxidase related content, leaves from at least 10 plants of each group after 4 days treatment were harvested. Each treatment included 3 biological replicates. Leaves were collected to determine the SOD, POD, and CAT activities, and the content of chlorophyll, H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e, MDA, soluble sugar, Na\\u003csup\\u003e+\\u003c/sup\\u003e and K\\u003csup\\u003e+\\u003c/sup\\u003e under both normal and salt stress conditons.\\u003c/p\\u003e\\n\\u003ch3\\u003eTranscriptome sequencing, differentially expressed gene screening and functional enrichment analysis\\u003c/h3\\u003e\\n\\u003cp\\u003eTotal RNA was extracted using TRIzol\\u0026reg; reagents according to the manufacturer's instructions. RNA quality was determined and quantified with 5300 Bioanalyzer (Agilent) and ND-2000 (NanoDrop Technologies). High quality RNA samples were used to construct sequencing libraries. The sweet potato RNA-SEQ transcriptome libraries were obtained from Illumina\\u0026reg; single-stranded mRNA Prep, Ligation (San Diego, CA), with a total RNA concentration of 1\\u0026micro;g. The sequencing libraries were performed on the DNBSEQ-T7 platform (PE150) using the DNBSEQ-T7RS Reagent Kit (FCL PE150) version 3.0. The original paired end reads are trimmed and quality controlled by fastp with default parameters. Then HISAT2 software was used to compare the mapping patterns of clean reads with reference genomes. The mapped readings for each sample are assembled with StringTie in a reference-based method. To identify differentially expressed genes (DEGs), the expression level of each transcript was calculated according to the TPM (the transcripts per million reads) method. RSEM is used to quantify gene abundance. The screening criteria for differentially expressed genes were |log2FC| \\u0026gt;=1 and padjust\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.05. GO functional enrichment and KEGG pathway analysis were performed wiht Goatools and Python scipy software, respectively.\\u003c/p\\u003e\\n\\u003ch3\\u003eQuantitative real-time PCR assays\\u003c/h3\\u003e\\n\\u003cp\\u003eEight randomly selected genes from the DEGs in the transcriptome were subjected to quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Detailed information regarding the gene-specific primers utilized in this research was shown in Supplementary Table \\u003cspan refid=\\\"MOESM1\\\" class=\\\"InternalRef\\\"\\u003eS1\\u003c/span\\u003e. RNA samples were collected from various sweet potato varieties under normal and salt stress conditions at two time points (0 and 2 days). Complementary DNA (cDNA) was synthesized from the extracted RNA using the HiScript II 1st Strand cDNA Synthesis Kit (Vazyme Biotech, Nanjing, China). Quantitative real-time PCR (qRT-PCR) was carried out using the LightCycler480 Real-Time PCR System along with ChamQTMSYBR\\u0026reg; qPCR Master Mix (Vazyme Biotech, Nanjing, China), following the protocol provided by the manufacturer. The relative expression levels of the selected genes were calculated using the 2\\u003csup\\u003e\\u0026minus;ΔΔCt\\u003c/sup\\u003e method, with three independent biological replicates included for each measurement.\\u003c/p\\u003e \\u003cdiv id=\\\"Sec7\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eStatistical analysis\\u003c/h2\\u003e \\u003cp\\u003eThe Student\\u0026rsquo;s t-test implemented in the Rbase package was used to assess statistical significance. Three biological replicates and three technical replicates were conducted to generate the mean values and standard deviations (SDs). Significant differences between different samples were determined using the multiple range test at P\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.05.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"Results\",\"content\":\"\\u003cdiv id=\\\"Sec9\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eFMG showed more resistant to salt stress than did YS25\\u003c/h2\\u003e \\u003cp\\u003eOur previous salt tolerance experiments showed that YS25 was a salt sensitive sweet potato variety with yellow flesh, while FMG was a salt tolerant sweet potato variety with white flesh (Fig \\u003cspan refid=\\\"MOESM1\\\" class=\\\"InternalRef\\\"\\u003eS1\\u003c/span\\u003e). To determine the difference in the resistance response to salt stress between the two types of sweet potato varieties, the 2-week-old YS25 and FMG plants were treated with 0 or 300 mM NaCl for 6 days, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e). After 2 days of salt treatment, YS25 plants showed a leaf dechlorosis phenotype, while FMG plants grew with green leaves until the 4th day. After 6 days, YS25 plants died, while FMG plants remained alive (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003eUnder salt stress conditions, the chlorophyll content in YS25 and FMG plants was severely affected (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eA, B). After four days treatment, the chlorophyll content in both YS25 and FMG decreased significantly (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eA, B). However, compared to YS25, the chlorophyll content in FMG was less affected by salt stress (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eA, B). To explore the impacts of salt stress on ion accumulation in two sweet potato varieties, we examined the content of K\\u003csup\\u003e+\\u003c/sup\\u003e, Na\\u003csup\\u003e+\\u003c/sup\\u003e and the K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratio in the leaves of 2-week-old plants. These plants were treated with 0 and 300 mM NaCl for 4 days (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eC, D, E). Under normal conditions, there was no difference in K\\u0026thinsp;+\\u0026thinsp;content in leaves of YS25 and FMG plants. Nevertheless, the Na\\u003csup\\u003e+\\u003c/sup\\u003e content in YS25 leaves was lower than that in FMG leaves (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eC, D). Under normal conditions, the content of K\\u003csup\\u003e+\\u003c/sup\\u003e in YS25 and FMG leaves was considerably higher than that of Na\\u003csup\\u003e+\\u003c/sup\\u003e (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eC, D). Also, the K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratio in YS25 leaves was higher than that in FMG under normal conditions (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eE). After salt treatment, salt stress induced the accumulation of Na\\u003csup\\u003e+\\u003c/sup\\u003e in the leaves of both YS25 and FMG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eD). Under salt stress treatment, there was no difference in the K\\u003csup\\u003e+\\u003c/sup\\u003e content between YS25 and FMG leaves (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eC). However, more Na\\u003csup\\u003e+\\u003c/sup\\u003e was accumulated in YS25 leaves than in FMG leaves (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eD). After salt stress treatment, there was no significant difference in the K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratio between YS25 and FMG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003eE).\\u003c/p\\u003e \\u003c/div\\u003e\\n\\u003ch3\\u003eAntioxidant defense systems were involved in the salt stress response of sweet potatos\\u003c/h3\\u003e\\n\\u003cp\\u003eTo further analyze the different responses of two sweet potato varieties to salt stress, we examined the antioxidant defense system between YS25 and FMG. When NaCl treatment was compared with CK treatment, the contents of MDA, H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e and soluble sugar were increased in YS25 and FMG leaves (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003eA, B, C). The increased MDA and H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e level in YS25 were significantly higher than that in FMG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003eA, B). On the contrary, the content of soluble sugar in FMG leaves was higher than YS25 under salt stress. (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003eC). Compared to CK treatment, NaCl treatment significantly increased antioxidant enzyme activity in YS25 and FMG leaves, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003eE). Under salt stress treatment, the change trend of antioxidant enzyme activity was the same in the two sweet potato varieties, and the antioxidant enzyme activities of SOD, CAT and POD were increased to different degrees (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003eD, E, F). However, the SOD, CAT and POD activities were increased significantly in FMG leaves under salt stress compared with YS25 (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003eD, E, F ).\\u003c/p\\u003e \\u003cdiv id=\\\"Sec11\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eA great number of differentially expressed genes were identified via transcriptome sequencing\\u003c/h2\\u003e \\u003cp\\u003eIn order to understand the difference of gene expression response between two sweet potato varieties under salt stress, we performed RNA-seq analysis. The differentially expressed genes (DEGs) in leaves of YS25 and FMG plants after 2 days of 0 mM and 300 mM NaCl treatment were analyzed (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig14\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eA, B). A high quality transcriptome sequencing, with a multiple bases of Q20 score\\u0026thinsp;\\u0026gt;\\u0026thinsp;97%, Q30\\u0026thinsp;\\u0026gt;\\u0026thinsp;92% and GC percentage\\u0026thinsp;\\u0026gt;\\u0026thinsp;46%, were generated with IlluminaHiSeq\\u0026trade;4000 (Table S2). In our experiment, we obtained 565.6\\u0026nbsp;million original readings from 12 samples (Table S2). After filtering the adapter sequence and low-quality reads, 547.5\\u0026nbsp;million clean reads were obtained (Table S2). To compare the expression of different genes in the transcriptome of two sweet potato varieties under different conditions (control and salt stress) (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig14\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eA, B). Upon the salt treatment, 7370 and 7068 DEGs, with 3351 and 2725 up-regulated, and 4019 and 4343 down-regulated, were respectively identified in YS25 and FMG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig14\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003eA, B; Table S3).\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec12\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eThe quality of RNA-Seq results was successfully validated with qRT-PCR\\u003c/h2\\u003e \\u003cp\\u003eTo check the reliability of the RNA-seq data, eight differentially expressed genes (DEGs) were chosen randomly for validation by qRT-PCR. The relative expression levels (Fpkm) of these eight genes in the RNA-seq were verified through qRT-PCR (using the 2\\u003csup\\u003e\\u0026minus;ΔΔCT\\u003c/sup\\u003e method). The results showed consistency in the alterations of gene expression levels between the qRT-PCR and RNA-seq analyses carried out in YS25 and FMG. This suggests that the quality of the RNA-seq data is reliable (Fig S2).\\u003c/p\\u003e \\u003cp\\u003e \\u003cb\\u003eThe GO enrichment terms of DEGs were different between YS25 and FMG under salt stress condition\\u003c/b\\u003e \\u003c/p\\u003e \\u003cp\\u003eTo investigate the potential role of differentially expressed genes in response to salt stress in different salt-resistant sweet potato varieties, we conducted a comprehensive annotation and genetic ontology terminology analysis. A total number of 821 and 740 GO terms in YS25 and FMG were respectively identified, including 447 BP-related, 91 CC-related and 283 MF-related GO terms in YS25, 390 BP-related, 74 CC-related and 276 MF-related GO terms in FMG (Table S3). Interestingly, we found that the identified DEGs in two sweet potato varieties under salt stress were mainly distributed in \\\"biological processes (BP)\\\" and \\\"cell components (CC)\\\" among the top 50 most enriched GO terms (Fig S3). We also found that the DEGs in two sweet potato varieties under salt stress were mainly distributed in \\\"biological processes (BP)\\\" among the top 20 most enriched GO terms (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig15\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). The top 20 GO terms of DEGs of two sweet potato varieties were compared. Only four GO terms were overlap (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig15\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). The GO terms enrichment of DEGs from different sweet potato varieties were significantly different.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec13\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eDEGs were enriched in different pathways between YS25 and FMG\\u003c/h2\\u003e \\u003cp\\u003eIn order to further understand the biological function of the identified DEGs in response to salt stress, we conducted a KEGG pathway enrichment analysis of DEGs. A total number of 126 pathways were identified in YS25 leaves after the salt treatment (Table S4). A total number of 130 pathways were identified in FMG leaves after the salt treatment (Table S4). Ten pathways in top 20 KEGG pathways, including \\u0026ldquo;Zeatin biosynthesis\\u0026rdquo;, \\u0026ldquo;Starch and sucrose metabolism\\u0026rdquo;, \\u0026ldquo;Galactose metabolism\\u0026rdquo;, \\u0026ldquo;Nitrogen metabolism\\u0026rdquo;, \\u0026ldquo;Flavonoid biosynthesis\\u0026rdquo;, \\u0026ldquo;Carotenoid biosynthesis\\u0026rdquo;, \\u0026ldquo;Folate biosynthesis\\u0026rdquo;, \\u0026ldquo;ABC transporters\\u0026rdquo;, \\u0026ldquo;Phenylpropanoid biosynthesis\\u0026rdquo; and \\u0026ldquo;Glycosphingolipid biosynthesis - globo and isoglobo series\\u0026rdquo; were identified in FMG leaves after the salt treatment (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e). Ten pathways in top 20 KEGG pathways, including \\u0026ldquo;Ribosome\\u0026rdquo;, \\u0026ldquo;Glycolysis / Gluconeogenesis\\u0026rdquo;, \\u0026ldquo;Glycine, serine and threonine metabolism\\u0026rdquo;, \\u0026ldquo;Monoterpenoid biosynthesis\\u0026rdquo;, \\u0026ldquo;Citrate cycle (TCA cycle)\\u0026rdquo;, \\u0026ldquo;Sesquiterpenoid and triterpenoid biosynthesis\\u0026rdquo;, \\u0026ldquo;Glucosinolate biosynthesis\\u0026rdquo;, \\u0026ldquo;Alanine, aspartate and glutamate metabolism\\u0026rdquo;, \\u0026ldquo;Porphyrin and chlorophyll metabolism\\u0026rdquo; and \\u0026ldquo;Steroid biosynthesis\\u0026rdquo; were identified in YS25 leaves after the salt treatment (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e). Ten pathways in top 20 KEGG pathways, including \\u0026ldquo;Photosynthesis\\u0026rdquo;, \\u0026ldquo;Photosynthesis - antenna proteins\\u0026rdquo;, \\u0026ldquo;Glyoxylate and dicarboxylate metabolism\\u0026rdquo;, \\u0026ldquo;Carbon fixation in photosynthetic organisms\\u0026rdquo;, \\u0026ldquo;Pentose phosphate pathway\\u0026rdquo;, \\u0026ldquo;Vitamin B6 metabolism\\u0026rdquo;, \\u0026ldquo;Anthocyanin biosynthesis\\u0026rdquo;, \\u0026ldquo;Fructose and mannose metabolism\\u0026rdquo;, \\u0026ldquo;Peroxisome\\u0026rdquo; and \\u0026ldquo;Plant hormone signal transduction\\u0026rdquo;, were both identified in YS25 and FMG leaves after the salt treatment (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e).\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec14\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eGenes in the peroxisome pathway were differentially expressed in YS25 and FMG\\u003c/h2\\u003e \\u003cp\\u003eOur previous experimental results showed that the activity of peroxidase in FMG was higher than YS25 (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003eD, E, F). The peroxisome pathway was one of the common pathways for the enrichment of DEGs in FMG and YS25 after salt stress (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e). We also compared the expression of DEGs involved in the peroxisome pathway. A distinct intervarietal specific expression pattern was observed (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig17\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003eA, B, C, D). In YS25, 2 SOD genes, 46 POD genes, 21 GST genes and 13 GPX genes were up-regulated by salt stress (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig17\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003eA, B, C, D). However, in FMG, three SOD genes, 60 POD genes, 37 GST genes and 16 GPX genes were up-regulated (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig17\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003eA, B, C, D). In the peroxisome pathway, the number of up-regulated DEGs in FMG were higher than YS25, and the up-regulated multiple of DEGs were also higher than YS25 (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig17\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003eA, B, C, D).\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec15\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eGenes in the key salt response pathways were differentially expressed in YS25 and FMG\\u003c/h2\\u003e \\u003cp\\u003eWe also screened several critical pathways in FMG, including \\u0026ldquo;Zeatin biosynthesis\\u0026rdquo;, \\u0026ldquo;Starch and sucrose metabolism\\u0026rdquo;, \\u0026ldquo;Galactose metabolism\\u0026rdquo;, \\u0026ldquo;Nitrogen metabolism\\u0026rdquo;, \\u0026ldquo;Flavonoid biosynthesis\\u0026rdquo; (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e). In Zeatin biosynthesis pathway, there are 10 up-regulated DEGs in YS25 and 9 up-regulated DEGs in FMG, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eA). In Starch and sucrose metabolism pathway, there are 27 up-regulated DEGs in YS25 and 26 up-regulated DEGs in FMG, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eB). In Galactose metabolism pathway, there are up-regulated 26 DEGs in YS25 and 30 up-regulated DEGs in FMG, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eC). In Nitrogen metabolism pathway, there are 9 up-regulated DEGs in YS25 and 9 up-regulated DEGs in FMG, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eD). In Flavonoid biosynthesis pathway, there are 27 up-regulated DEGs in YS25 and 26 up-regulated DEGs in FMG, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eE). Comparing the DEGs heatmaps of these five pathways in YS25 and FMG revealed that the gene expression levels were much higher in FMG than YS25 without treatment (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eA, B, C, D, E). After salt stress treatment, there were no significant difference in the number of up-regulated ddegs between the two varieties, but the change ratio of up-regulated DEGs in FMG was higher than YS25 (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eA, B, C, D, E).\\u003c/p\\u003e \\u003cp\\u003e \\u003cb\\u003ePhysiological changes and key salt related gene expression were further verified in the sweet potato varieties of XGH and QT\\u003c/b\\u003e \\u003c/p\\u003e \\u003cp\\u003eTo verify the physiological responses in other sweet potato varieties to salt stress, We selected XGH and QT sweet potato varieties similar to YS25 and FMG (Fig S4), respectively. 2-week-old XGH and QT plants were treated with 0 or 300 mM NaCl for 6 days, respectively (Fig S5). After 4 days of salt treatment, XGH plants showed a leaf dechlorosis phenotype, while QT plants grew with green leaves. After 6 days, YS25 plants died, while FMG plants remained alive (Fig S5). After 4 days of salt treatment, the chlorophyll content in XGH and QT were decreased significantly, but the chlorophyll content in QT was less affected by salt stress than XGH (Fig S6A, B). To understand the effects of salt stress on ion accumulation in different sweet potato varieties, we investigated the content of K\\u003csup\\u003e+\\u003c/sup\\u003e, Na\\u003csup\\u003e+\\u003c/sup\\u003e and the K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratio in the leaves of 2-week-old XGH and QT plants treated with 0 and 300 mM NaCl for 4 days (Fig S6C, D, E). Under normal conditions, the K\\u003csup\\u003e+\\u003c/sup\\u003e and Na\\u003csup\\u003e+\\u003c/sup\\u003e contents in XGH leaves was lower than that of QT leaves (Fig S6C, D). The K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratio in QT leaves was higher than that of XGH in normal conditions (Fig S6E). After salt treatment, salt stress induced K\\u003csup\\u003e+\\u003c/sup\\u003e and Na\\u003csup\\u003e+\\u003c/sup\\u003e accumulation in XGH and QT leaves (Fig S6C, D). Under salt stress treatment, more K\\u003csup\\u003e+\\u003c/sup\\u003e and Na\\u003csup\\u003e+\\u003c/sup\\u003e contents were accumulated in XGH leaves than QT (Fig S6C, D). There was no difference in the K\\u003csup\\u003e+\\u003c/sup\\u003e/ Na\\u003csup\\u003e+\\u003c/sup\\u003e ratio between XGH and QT after salt stress treatment (Fig S6E).\\u003c/p\\u003e \\u003cp\\u003eTo confirm that the antioxidant defense systems in other sweet potato varieties were also play an important role, we examined the antioxidant defense system between the two other varieties. When NaCl treatment was compared with CK treatment, the MDA content was increased in YS25 and FMG leaves (Fig S7). The increased MDA level in YS25 was significantly higher than that in FMG (Fig S7A). NaCl treatment significantly increased the H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e contents in YS25 and FMG leaves, respectively, compared to CK treatment (Fig S7B). Under salt stress, the variation trend of soluble sugar was the same as that of malondialdehyde (Fig S7C). Under salt stress treatment, the change trend of antioxidant enzyme activity was the same in the two sweet potato varieties, and the antioxidant enzyme activities of SOD, CAT and POD were increased to different degrees (Fig S7D, E, F). SOD, CAT and POD activities increased significantly in FMG leaves under salt stress compared with YS25 (Fig S7D, E, F). To verify the candidate genes involved in the regulation of salt stress response, 24 up-regulated genes were selected for qRT-PCR analysis in different sweet potato cultivars (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e9\\u003c/span\\u003eA, B, C, D, E, F, G). Most of the selected DEGs were expressed higher in QT than in XHG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e9\\u003c/span\\u003eA, B, C, D, E, F, G).\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eSweet potato is a food crop with high economic value in China (Zhang et al., 2017; Yu et al., 2015; Meng et al., 2020). Sweet potato is a salt sensitive plant (Yu et al., 2015). Mining and identifying salt tolerant genes of sweet potato is beneficial to improve salt tolerance of sweet potato through biotechnology breeding. the tolerance of different varieties to salt stress is significantly different. Previous transcriptome studies related to salt stress in sweet potato were few, and the results were inconsistent (Zhang et al., 2017; Meng et al., 2020). This indicated that there were differences in salt stress response between different types and different sources of sweet potato varieties.\\u003c/p\\u003e \\u003cp\\u003eIn this study, two sweet potato varieties, YS25 and FMG, were selected in the identification of salt tolerance of various sweet potato varieties. YS25 and FMG were two important sweet potato varieties in China because of their excellent taste. This study first assessed the resistance of two sweet potato varieties to salt stress. According to the analysis of leaf phenotype and physiological indexes under salt treatment, FMG was identified as a salt tolerant variety and YS25 as a salt sensitive variety (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e, Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e, Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e). Similar to previous studies, compared with salt sensitive varieties, salt tolerant varieties have higher antioxidant enzyme activity under salt stress, which makes the leaves of salt tolerant varieties less damaged by salt stress (Song et al., 2023; Shi and Gu, 2020; Farooq et al., 2024). In order to further understand the salt tolerance mechanisms of different sweet potato varieties, high-throughput transcriptome sequencing was performed on two salt stressed varieties (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig14\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e). Under salt stress, we identified 7370 differentially expressed genes in salt sensitive variety YS25 and 7068 differentially expressed genes in salt tolerant variety FMG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig14\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e). In both salt tolerant and salt sensitive varieties, the number of downregulated genes exceeded the number of upregulated genes, which was consistent with previous studies (Zhang et al., 2017).\\u003c/p\\u003e \\u003cp\\u003eWe also compared the GO and KEGG enrichments of DEGs after salt treatment between YS25 and FMG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig15\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e; Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e; Table S4; Table S5). Interestingly, We found that DEGs of YS25 and FMG were more enriched in \\u0026ldquo;biological processes (BP)\\u0026rdquo; and \\u0026ldquo;Molecular function (MF)\\u0026rdquo; (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig15\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e; Table S4). We compared the GO terms of the top 50 most enriched DEGs in the two varieties under salt stress. The results showed that DEGs were mainly enriched in the GO terms belonging to BP and CC (Fig S3). The top 20 GO enrichment terms of DEGs from different sweet potato varieties were significantly different (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig15\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). Previous studies on the transcriptome of salt stress had shown that the pathways involved in plant salt stress response are complex and diverse. The Nitrogen metabolism pathway, the plant hormone signal transduction pathway, the plant-pathogen interactions pathway, the starch and sucrose metabolism pathway, the biosynthesis of amino acids pathway, the flavonoid biosynthesis pathway and many other pathways played an important role in plant salt tolerance (Chen et ql., 2022; Gao et al., 2024; Shabala, 2013; Shi and Gu, 2020; Zhang et al., 2023). In our study, the results of KEGG pathways enrichment of DEGs in YS25 and FMG under salt stress were similar to previous studies (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e; Table S5). The top 20 KEGG pathways of DEGs in the two varieties were compared. Some important salt-stress-related KEGG pathways, including: the Pentose phosphate pathway pathway, the Anthocyanin biosynthesis pathway, the Fructose and mannose metabolis pathway, the Peroxisom pathway and the Plant hormone signal transduction pathway, were both in YS25 and FMG. In addition to the common salt-stress-related pathways in the top 20 KEGG pathways, salt sensitive varieties YS25 and salt tolerant varieties FMG had different KEGG pathways to cope with salt stress (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e; Table S5). The KEGG pathways identified in FMG, including: the Zeatin biosynthesis pathway, the Starch and sucrose metabolis pathway, the Galactose metabolis pathway, the Nitrogen metabolis pathway, the Flavonoid biosynthesis pathway, the Carotenoid biosynthesis pathway, the Folate biosynthesis pathway, the ABC transporters pathway, the Phenylpropanoid biosynthesi pathway and the Glycosphingolipid biosynthesis-globo and isoglobo series pathway were likely to play an important role in salt stress response (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig16\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e; Table S5). We compared the expression of DEGs in the important pathways of salt stress response by heatmap (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig17\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003eA, B, C, D; Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eA, B, C, D, E). We found that the expression of some key genes in these important salt stress response pathways was significantly up-regulated in the salt tolerant variety FMG (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig17\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003eA, B, C, D; Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig18\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003eA, B, C, D, E).\\u003c/p\\u003e \\u003cp\\u003eWe identified another two varieties in the salt tolerance screening of different sweet potato varieties, salt sensitive variety XGH and salt tolerant variety QT. These two varieties are similar to YS25 and FMG not only in plant phenotype, but also in salt stress response (Fig S4; Fig S5). Comparative transcriptomic analysis revealed candidate genes related to anthocyanin biosynthesis in \\\"red Bartlett\\\" pear (\\u003cem\\u003ePyrus communis\\u003c/em\\u003e L.) and validated these candidate genes in another variety (Dai et al., 2022). In our study, we also validated these candidate genes associated with salt stress response in other sweet potato varieties. Similar to previous studies, candidate genes were also involved in the salt stress response of salt tolerant sweet potato varieties with similar phenotypes (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e9\\u003c/span\\u003e). The possible functions of these salt response-related genes need to be evaluated in detail in future.\\u003c/p\\u003e\"},{\"header\":\"Conclusions\",\"content\":\"\\u003cp\\u003eThe response of different sweet potato varieties to salt stress was analyzed. DEGs induced by salt stress in salt sensitive variety YS25 and salt tolerant variety FMG were identified. Significant differences were observed in GO and KEGG enrichment pathways of DEGs in between YS25 and FMG under salt stress condition. DEGs in the salt tolerant variety FMG were enriched in salt stress response pathways, such as the zeatin biosynthesis pathway, the starch and sucrose metabolis pathway, the galactose metabolis pathway, the nitrogen metabolis pathway and the flavonoid biosynthesis pathway. Salt tolerant candidate genes also showed the same response to salt stress in XGH and QT. Our results will help to deepen the understanding of the mechanism of salt tolerance in sweet potato and provide potential genetic resources for the genetic selection and breeding of new sweet potato varieties.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eFunding\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThis work has been jointly supported by the following grants: the Natural Science Foundation of Shandong Province, China (ZR2024QC076, ZR2025QC352); the Innovation Project of Shandong Academy of Agricultural Sciences, China (CXGC2025B05); the Taishan Scholars Program (tsqn202312290); the National Natural Science Foundation of China (32071733, 32371915); the Sericultural Industry Technical System of Shandong Province (grant no. SDAIT-18-09).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eConflict of Interest\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eData availability\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAll raw reads were deposited in the Sequence Read Archive (SRA) database in NCBI with accession number PRJNA1242390.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAuthor contributions\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eRao Fu, Ruxia Li and Hongxia Zhang conceived and designed the experiments; Haiyang Zhang, Meng Li, Junlin Li, Dongyang Li, Chuanjie Chen, Yingyu Gu, Chi Zhang and Xiaoyan Liang performed the experiments and data analysis. Haiyang Zhang, Rao Fu, Ruxia Li and Hongxia Zhang wrote and revised the manuscript. All authors have read and approved the paper.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n \\u003cli\\u003eAdu Donyina G, Szarvas A, Opoku VA, Miko E, Tar M, Cz\\u0026oacute;bel S, Monostori T (2025) Enhancing sweet potato production: a comprehensive analysis of the role of auxins and cytokinins in micropropagation. Planta, 261(4), 74. doi: 10.1007/s00425-025-04650-z\\u003c/li\\u003e\\n \\u003cli\\u003eChen CX, Shang XL, Sun MY, Tang SY, Khan A, Zhang D, Yan HD, Jiang YX, Yu FF, Wu YR, Xie Q (2022) Comparative Transcriptome Analysis of Two Sweet Sorghum Genotypes with Different Salt Tolerance Abilities to Reveal the Mechanism of Salt Tolerance. Int J Mol Sci, 23, 2272. https://doi.org/10.3390/ijms23042272\\u003c/li\\u003e\\n \\u003cli\\u003eCui XY, Chen JM, Li S, Shao A, \\u0026nbsp;Fu JM (2025). Growth and physiological characteristics of forage bermudagrass in response to salt stress. BMC plant biology, 25(1), 269. https://doi.org/10.1186/s12870-025-06281-8\\u003c/li\\u003e\\n \\u003cli\\u003eDai XN, Li QY, Jiang FD, Song ZZ, Tang XL, Su SQ, Yao RT, Yang HY, Yang YQ, Zhang HX, Li JZ (2022) Transcriptome analysis of branches reveals candidate genes involved in anthocyanin biosynthesis of \\u0026lsquo;Red Bartlett\\u0026rsquo; pear (\\u003cem\\u003ePyrus\\u003c/em\\u003e \\u003cem\\u003ecommunis\\u003c/em\\u003e L.). Scientia Horticulturae, 305. https://doi.org/10.1016/j.scienta.2022.111392.\\u003c/li\\u003e\\n \\u003cli\\u003eFarooq MA, Zeeshan Ul Haq M, Zhang L,Wu S, Mushtaq N, Tahir H, Wang Z (2024) Transcriptomic Insights into Salt Stress Response in Two Pepper Species: The Role of MAPK and Plant Hormone Signaling Pathways. Int J Mol Sci, 25, 9355. https://doi.org/10.3390/ ijms25179355\\u003c/li\\u003e\\n \\u003cli\\u003eFlowers TJ, Colmer TD (2008) Salinity tolerance in halophytes. New Phytol 179, 945\\u0026ndash;963. https://doi.org/10.1111/j.1469-8137.2008.02531.x\\u003c/li\\u003e\\n \\u003cli\\u003eGao QC, Yu RN, Ma XS, Wuriyanghan H, Yan F (2024) Transcriptome Analysis for Salt-Responsive Genes in Two Different Alfalfa (\\u003cem\\u003eMedicago\\u003c/em\\u003e \\u003cem\\u003esativa\\u003c/em\\u003e L.) Cultivars and Functional Analysis of \\u003cem\\u003eMsHPCA1\\u003c/em\\u003e. Plants, 13, 1073. https://doi.org/10.3390/ plants1308107C\\u003c/li\\u003e\\n \\u003cli\\u003eHu YF, ZhaoHY, Xue LY, Nie N, Zhang H, Zhao N, He SZ, Liu QC, Gao SP, Zhai H (2024) IbMYC2 Contributes to Salt and Drought Stress Tolerance via Modulating Anthocyanin Accumulation and ROS-Scavenging System in Sweet Potato. Int J Mol Sci, 25, 2096. https://doi.org/10.3390/ijms25042096\\u003c/li\\u003e\\n \\u003cli\\u003eJin R, Kim BH, Ji CY, Kim HS, Li HM, Ma DF, Kwak SS (2017) Overexpressing \\u003cem\\u003eIbCBF3\\u0026nbsp;\\u003c/em\\u003eincreases low temperature and drought stress tolerance in transgenic sweet potato. Plant Physiol Biochem, 118:45-54. https://doi.org/10.1016/j.plaphy.2017.06.002\\u003c/li\\u003e\\n \\u003cli\\u003eKang C, Zhai H, He SZ, Zhao N, Liu QC (2019) \\u0026nbsp;A novel sweet potato bZIP transcription factor gene, \\u003cem\\u003eIbbZIP1\\u003c/em\\u003e, is involved in salt and drought tolerance in transgenic\\u0026nbsp;Arabidopsis.\\u0026nbsp;Plant Cell Rep, 38, 1373\\u0026ndash;1382. https://doi.org/10.1007/s00299-019-02441-x\\u003c/li\\u003e\\n \\u003cli\\u003eLi H, Liu L, Kong XH, Wang XW, Si AJ, Zhao FX, Huang Q, Yu Y, Chen ZW (2025) Time-Course Transcriptomics Analysis Reveals Molecular Mechanisms of Salt-Tolerant and Salt-Sensitive Cotton Cultivars in Response to Salt Stress. Int J Mol Sci, 26, 329. https://doi.org/ 10.3390/ijms26010329\\u003c/li\\u003e\\n \\u003cli\\u003eLi N, Zhang ZH, Chen ZJ, Cao BL, Xu K (2021) Comparative Transcriptome Analysis of Two Contrasting Chinese Cabbage (\\u003cem\\u003eBrassica\\u003c/em\\u003e \\u003cem\\u003erapa\\u003c/em\\u003e L.) Genotypes Reveals That Ion Homeostasis Is a Crucial Biological Pathway Involved in the Rapid Adaptive Response to Salt Stress. Front Plant Sci, 12:683891. https://doi.org/10.3389/fpls.2021.683891\\u003c/li\\u003e\\n \\u003cli\\u003eLi RX, Fu R, Li M, Song YJ, Li JL, Chen CJ, Gu YY, Liang XY, Nie WJ, Ma L, Wang XY, Zhang HY, Zhang HX (2023) Transcriptome profiling reveals multiple regulatory pathways of Tamarix chinensis in response to salt stress. Plant Cell Rep 42, 1809\\u0026ndash;1824. https://doi.org/10.1007/s00299-023-03067-w\\u003c/li\\u003e\\n \\u003cli\\u003eLin CC, Zheng SS, Liu K, Yu R, Guan PY, Hu BG, Jiang LL, Su MY, Hu GD, Chen QS, Zhang X (2025) Elucidating the molecular basis of salt tolerance in potatoes through miRNA expression and phenotypic analysis. Sci Rep 15, 2635. https://doi.org/10.1038/s41598-025-86276-5\\u003c/li\\u003e\\n \\u003cli\\u003eLiu EL, Li ZQ, Luo ZQ, XuLL, Jin P, Ji S, Zhou GH,Wang ZY, Zhou ZL, Zhang H (2023) Genome-Wide Identification of DUF668 Gene Family and Expression Analysis under Drought and Salt Stresses in Sweet Potato [\\u003cem\\u003eIpomoea batatas\\u003c/em\\u003e (L.) Lam]. Genes, 14, 217. https:// doi.org/10.3390/genes14010217\\u003c/li\\u003e\\n \\u003cli\\u003eLuo Y, Reid R, Freese D, \\u0026nbsp;Li CB, Watkins J, Shi HZ, Zhang HY, Loraine A, Song BH (2017) Salt tolerance response revealed by RNA-Seq in a diploid halophytic wild relative of sweet potato. Sci Rep, 7, 9624. https://doi.org/10.1038/s41598-017-09241-x\\u003c/li\\u003e\\n \\u003cli\\u003eMansour MMF, Emam MM, Salama KHA, Morsy AA (2021) Sorghum under saline conditions: Responses, tolerance mechanisms, and management strategies. Planta, 254, 24. https://doi.org/10.1007/s00425-021-03671-8\\u003c/li\\u003e\\n \\u003cli\\u003eMeng XQ, Liu SY, Zhang CB, He JN, Ma DF, Wang X, Dong TT, Guo F, Cai J, Long TD, Li ZY, Zhu MK (2023) The unique sweet potato NAC transcription factor IbNAC3 modulates combined salt and drought stresses. Plant Physiol, 2;191(1):747-771. https://doi.org/10.1093/plphys/kiac508\\u003c/li\\u003e\\n \\u003cli\\u003eMuchate NS, Nikalje GC, Rajurkar NS, Suprasanna P, Nikam TD (2016) Plant Salt Stress: Adaptive Responses, Tolerance Mechanism and Bioengineering for Salt Tolerance. Bot Rev, 82, 371\\u0026ndash;406. https://doi.org/10.1007/s12229-016-9173-y\\u003c/li\\u003e\\n \\u003cli\\u003eMunns R, Tester M (2008) Mechanisms of salinity tolerance. Annu Rev Plant Biol, 59 (1): 651-681. https://doi.org/10.1146/annurev.arplant.59.032607.092911\\u003c/li\\u003e\\n \\u003cli\\u003eOuertani RN, Arasappan D, Abid G, Ben Chikha M, Jardak R, Mahmoudi H, Mejri S, Ghorbel A, Ruhlman TA, Jansen RK (2021) Transcriptomic analysis of salt-stress-responsive genes in barley roots and leaves. Int J Mol Sci, 22, 8155. https://doi.org/10.3390/IJMS22158155\\u003c/li\\u003e\\n \\u003cli\\u003eRickman TE, Adams AK, Wadl PA, Yencho GC, Olukolu BA (2025). Genome-wide associations of sweet potato metabolites enhance genomic prediction and identify genes in metabolic and regulatory pathways.\\u0026nbsp;Scientific reports,\\u0026nbsp;15(1), 9657. https://doi.org/10.1038/s41598-025-93415-5\\u003c/li\\u003e\\n \\u003cli\\u003eShabala S 2013 Learning from halophytes: physiological basis and strategies to improve abiotic stress tolerance in crops. Ann Bot, 112, 1209\\u0026ndash;1221.\\u003c/li\\u003e\\n \\u003cli\\u003eShi PB, Gu MF (2020) Transcriptome analysis and differential gene expression profiling of two contrasting quinoa genotypes in response to salt stress. BMC Plant Biol, 20, 568. https://doi.org/10.1186/s12870-020-02753-1\\u003c/li\\u003e\\n \\u003cli\\u003eSingh A, Roychoudhury A (2021) Gene regulation at transcriptional and post-transcriptional levels to combat salt stress in plants. Physiol Plant, 173, 1556\\u0026ndash;1572. https://doi.org/10.1111/ppl.13502\\u003c/li\\u003e\\n \\u003cli\\u003eSong WX, Gao XQ, Li HP, Li SX, Wang J, Wang X, Wang TR, Ye YN, Hu PF, Li XH, Fu BZ (2023) Transcriptome analysis and physiological changes in the leaves of two \\u003cem\\u003eBromus\\u003c/em\\u003e \\u003cem\\u003einermis\\u003c/em\\u003e L. genotypes in response to salt stress. Front Plant Sci, 14:1313113. https://doi.org/10.3389/fpls.2023.1313113\\u003c/li\\u003e\\n \\u003cli\\u003eWang C, Lei J, Jin XJ, Chai SS, Jiao CH, Yang XS, Wang LJ (2024) A Sweet Potato MYB Transcription Factor IbMYB330 Enhances Tolerance to Drought and Salt Stress in Transgenic Tobacco. Genes, 2024, 15, 693. https://doi.org/10.3390/ genes15060693\\u003c/li\\u003e\\n \\u003cli\\u003eWang HY, Liu MY, Yang ST, Qiao S, Song W, Tan WF, Wang F (2025) Genome-wide analysis of PHT gene family and their role in LP and salt stress in sweet potato, Plant Physiol Biochem, \\u0026nbsp;109642. https://doi.org/10.1016/j.plaphy.2025.109642\\u003c/li\\u003e\\n \\u003cli\\u003eWang M, Xia G (2018) The landscape of molecular mechanisms for salt tolerance in wheat. Crop J, 6, 42\\u0026ndash;47. https://doi.org/10.1016/j.cj.2017.09.002\\u003c/li\\u003e\\n \\u003cli\\u003eWu JY, Su YR, Pan ZY, Wang YM, Zhang YJ, Li LD, Jiang JH, Cao XY (2024) Identification of WRKY transcription factors in Ipomoea pes-caprae and functional role of IpWRKY16 in sweet potato salt stress response. BMC Plant Biol, 24, 1190. https://doi.org/10.1186/s12870-024-05928-2\\u003c/li\\u003e\\n \\u003cli\\u003eYang Z, Wang Y, Cheng QR, Zou X, Yang YX, Li P, Wang SJ, Su Y, Yang DJ, Kim HS, Jia XY, Li LZ, Kwak SS, Wang WB (2024) Overexpression of sweet potato glutamylcysteine synthetase (IbGCS) in Arabidopsis confers tolerance to drought and salt stresses. J Plant Res, 137, 669\\u0026ndash;683. https://doi.org/10.1007/s10265-024-01548-x\\u003c/li\\u003e\\n \\u003cli\\u003eYu YC, Xu T, Li X, Tang J, Ma DF, Li ZY, Sun J (2015) NaCl-induced changes of ion homeostasis and nitrogen metabolism in two sweet potato (\\u003cem\\u003eIpomoea\\u003c/em\\u003e \\u003cem\\u003ebatatas\\u003c/em\\u003e L.). nvironmental and Experimental Botany, 23-36, 0098-8472, https://doi.org/10.1016/j.envexpbot.2015.12.006.\\u003c/li\\u003e\\n \\u003cli\\u003eZelm van E, Zhang Y, Testerink C (2020) Salt tolerance mechanisms of plants. Annu Rev Plant Biol 29, 71:403-433. https://doi.org/10.1146/annurev-arplant-050718-100005\\u003c/li\\u003e\\n \\u003cli\\u003eZhang C, Chen B, Zhang P, Han Q, Zhao G, \\u0026nbsp;Zhao F (2023) Comparative Transcriptome Analysis Reveals the Underlying Response Mechanism to Salt Stress in Maize Seedling Roots. Metabolites, 13, 1155. https://doi.org/10.3390/metabo13111155\\u003c/li\\u003e\\n \\u003cli\\u003eZhang F, Zhu GZ, Du L, Shang XG, Cheng CZ, Yang B, Hu Y, Cai CP, Guo WZ (2016) Genetic regulation of salt stress tolerance revealed by RNA-Seq in cotton diploid wild species, Gossypium davidsonii. Sci Rep, 6, 20582. https://doi.org/10.1038/s41598-019-45848-y\\u003c/li\\u003e\\n \\u003cli\\u003eZhang H, Zhang Q, Zhai H, Li Y, Wang XF, Liu QC, He SZ (2017) Transcript profile analysis reveals important roles of jasmonic acid signalling pathway in the response of sweet potato to salt stress. Sci Rep, 7, 40819. https://doi.org/10.1038/srep40819.\\u003c/li\\u003e\\n \\u003cli\\u003eZhao HY, Zhao HQ, Hu YF, Zhang SS, He SZ, Zhang H, Zhao N, Liu QC, Gao SP, Zhai H (2022) Expression of the Sweet Potato MYB Transcription Factor \\u003cem\\u003eIbMYB48\\u003c/em\\u003e Confers Salt and Drought Tolerance in Arabidopsis. Genes, 13, 1883. https://doi.org/10.3390/genes13101883\\u003c/li\\u003e\\n \\u003cli\\u003eZhao SS, Zhang QK, Liu MY, Zhou HP, Ma CL, Wang PP (2021) Regulation of Plant Responses to Salt Stress. Int J Mol Sci, 22, 4609. https://doi.org/10.3390/ijms22094609\\u003c/li\\u003e\\n \\u003cli\\u003eZhu JK (2016) Abiotic stress signaling and responses in plants. Cell, 167, 313\\u0026ndash;324. doi: 10.1016/j.cell.2016.08.029\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"plant-cell-reports\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"pcre\",\"sideBox\":\"Learn more about [Plant Cell Reports](https://www.springer.com/journal/299)\",\"snPcode\":\"299\",\"submissionUrl\":\"https://submission.nature.com/new-submission/299/3\",\"title\":\"Plant Cell Reports\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false},\"keywords\":\"Sweet potato, Transcriptome, Salt resistance, Regulatory pathways\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-8517679/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-8517679/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eSweet potato (\\u003cem\\u003eIpomoea batatas\\u003c/em\\u003e (L.) Lam.) is an important food crop with high nutritional and economic value. However, the mechanism regulating the resistance of different sweet potato varieties to salt stress is unclear. Here, a systematic was conducted with the salt sensitive variety YS25 and salt tolerant variety FMG in response to salt stress. Phenotypic and physiochemical analyses demonstrated that under salt stress condition, the growth of FMG was less affected. It showed more vigorous growth, accompanied with less chlorophyll loss and sodium, malondialdehyde (MDA) and H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e accumulation, than did YS25. It also showed higher soluble sugar content and superoxide dismutase (SOD), guaiacol peroxidase (POD) and catalase (CAT) enzymatic activity. Further transcriptomic analyses respectively identified 7370 and 7068 differential expression genes (DEGs) in YS25 and FMG. Gene ontology (GO) term analyses revealed that they were significantly rich in the terms of \\\"biological processes\\\" and \\\"molecular functions\\\". Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses showed that DEGs in the salt tolerant variety FMG were significantly enriched in the zeatin biosynthesis pathway, the starch and sucrose metabolis pathway, the galactose metabolis pathway, the nitrogen metabolis pathway and the flavonoid biosynthesis pathway. Expressions of the key genes in these regulatory pathways were further confirmed with quantitative real-time polymerase chain reaction (qRT-PCR) assays in the salt sensitive sweet potato cultivar XGH and the salt tolerant cultivar QT. Our studies provide a novel approach to the mining of new gene targets usable for breeding of salt tolerant sweet potato.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Transcriptome profiling comparison between the salt sensitive and tolerant cultivars of sweet potato reveals the key regulatory pathways in response to high salt stress\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2026-01-19 10:33:28\",\"doi\":\"10.21203/rs.3.rs-8517679/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Revision requested\",\"date\":\"2026-01-28T10:53:33+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-01-28T09:23:07+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-01-28T05:44:56+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-01-20T06:33:17+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2026-01-20T05:37:15+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"256759399185616438224905695205721843534\",\"date\":\"2026-01-14T13:49:17+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"163500740023650985584218206546906975604\",\"date\":\"2026-01-14T13:27:54+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"28876717852449772058536624756466225079\",\"date\":\"2026-01-14T13:14:04+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"320582767544569920875395179391039503216\",\"date\":\"2026-01-14T13:06:24+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"23701301246217824941162182853769363772\",\"date\":\"2026-01-14T13:00:25+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2026-01-14T12:33:58+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2026-01-09T07:24:26+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2026-01-09T07:24:12+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Plant Cell Reports\",\"date\":\"2026-01-05T06:21:50+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"plant-cell-reports\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"pcre\",\"sideBox\":\"Learn more about [Plant Cell Reports](https://www.springer.com/journal/299)\",\"snPcode\":\"299\",\"submissionUrl\":\"https://submission.nature.com/new-submission/299/3\",\"title\":\"Plant Cell Reports\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false}}],\"origin\":\"\",\"ownerIdentity\":\"873e134a-52e6-42c4-8091-716e165266c5\",\"owner\":[],\"postedDate\":\"January 19th, 2026\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"in-revision\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2026-01-28T11:08:24+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2026-01-19 10:33:28\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-8517679\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-8517679\",\"identity\":\"rs-8517679\",\"version\":[\"v1\"]},\"buildId\":\"XKTyCvWXoU3ODBz1xrDgd\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}