Paraglomus and Glomus Arbuscular Mycorrhizal Fungi induce the Green Tea Catechin Quality Index and Phosphorus bioavailability in Tropical soils

Paraglomus and Glomus Arbuscular Mycorrhizal Fungi induce the Green Tea Catechin Quality Index and Phosphorus bioavailability in Tropical soils | 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 Paraglomus and Glomus Arbuscular Mycorrhizal Fungi induce the Green Tea Catechin Quality Index and Phosphorus bioavailability in Tropical soils Pei Yuan, Yingzi Wang, Jianwei Peng, Ya Chen, Jinjing Li, Mamdouh A. Eissa, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5424269/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 20 Feb, 2025 Read the published version in Mycorrhiza → Version 1 posted 8 You are reading this latest preprint version Abstract Soil microbes have an impact on the quality of green tea leaves in addition to soil conditions and Camellia sinensis cultivar. Arbuscular mycorrhizal (AM) fungi can significantly improve soil quality and crop productivity, however, the specific AM fungal groups that affect the catechin quality index (CQI) of green tea are not yet clear. In the present study, rhizosphere soil samples, root samples, and fresh tea leaves from six different Camellia sinensis cultivars in Hunan Province, China were collected. Utilizing high-throughput Illumina amplicon sequencing technology, the taxonomic diversity and community composition of AM fungi in the rhizosphere soil and roots were investigated, as well as the mycorrhizal colonization rate. It was discovered that the two main AM fungal genera in the Camellia sinensis roots and rhizosphere were Paraglomus and Glomus. A higher catechin quality index (HCQI) correlates with greater accumulation of Paraglomus in the roots of Camellia sinensis. Tea cultivar and rhizosphere soil’s available phosphorus content significantly affected the mycorrhizal colonization rate and the composition of the AM fungal community within the roots. The mycorrhizal colonization rate impacted the catechin composition, consequently influencing the catechin quality index of green tea. Furthermore, fluctuations in the proportional presence of Paraglomus and Glomus within the roots of Camellia sinensis notably affected the CQI. In summary, heightened mycorrhizal colonization and enhanced Paraglomus prevalence substantially elevate the CQI of green tea. This finding was of considerable importance for the application of AM fungi in the production of high-quality green tea. Tea cultivar Rhizosphere Mycorrhizal colonization Diversity Catechin quality index Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Highlights Arbuscular mycorrhizal (AM) influenced the catechin quality index (CQI) of green tea. Paraglomus and Glomus were the dominant AM fungal genera. Paraglomus contributed positively to the enhancement of CQI in green tea. Rhizospheric phosphorus levels markedly affected tea plant mycorrhizal colonization. Introduction Camellia sinensis , a crop of significant economic importance originating from China, has now been widely cultivated in over 60 countries worldwide (Drew, 2019 ). The Camellia sinensis shoots and leaves, when processed into tea, contain a variety of secondary metabolites beneficial to human health, including catechins and amino acids (Ahammed et al., 2022). These secondary metabolites are crucial in determining the quality of the tea. Predominant among the polyphenols in green tea, catechins exhibit distinctive astringent qualities, encompassing bitterness and astringency, appealing to a diverse consumer palate (Hung et al., 2010 ). In comparison with other categories of tea, green tea is particularly abundant in natural catechins, which include epicatechin (EC), catechin (DL-C), epicatechin (ECG), epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG) (Kilel et al., 2013 ). Epigallocatechin gallate (EGCG), a major and beneficial bioactive compound in green tea, exhibits a multitude of effects, including antimicrobial, antiviral, cardiovascular protection, and antitumor activities (Wan et al., 2022; Yang et al., 2024 ). Catechin Quality Index is a widely recognized metric for assessing green tea quality, directly associated with its delicacy and superior attributes. Its calculation method is the sum of the contents of EGCG and ECG divided by the content of EGC, multiplied by 100 (Kilel et al., 2013 ; Wang et al., 2024 ). The excellence of fresh tea leaves stems not only from the tea varieties but also from the interplay of soil characteristics and the soil's microbial community (Xin et al., 2024 ). Soil phosphorus is crucial for the growth of Camellia sinensis, influencing the biosynthesis of catechins and consequently affecting the quality of green tea. Phosphorus deficiency is associated with decreased levels of total phenolics and amino acids in tea leaves, consequently impairing the taste characteristics of tea infusions (Lin et al., 2012 ). Additionally, the reciprocal influences of phosphorus and photosynthetic photon flux density on catechins are intricate, with phosphorus status playing a crucial part in modulating the impact of light exposure on tea quality (Kc et al., 2022 ). AM fungi are beneficial soil microbes that establish symbiotic associations with plants, aiding the assimilation of critical nutrients like nitrogen and phosphorus from the soil in return for carbon sourced from photosynthesis (Gao et al., 2023 ; Neuenkamp et al., 2018 ). Tea production is predominantly concentrated in China and India, and a variety of AM fungi species have been discovered in tea plantations across these nations (Liu et al., 2021a ). AM fungi, by establishing a mutually beneficial association with the root systems of Camellia sinensis , enhance the absorption of water and nutrients, strengthen the plants' tolerance to stress, and may positively influence the quality of the tea leaves (Chen et al., 2021 ). Inoculation with AM fungi significantly enhanced the levels of catechins, a group of phenolic compounds, with both the aerial and root tissues of Valeriana jatamansi (Jugran et al., 2015 ). The identity of the plant host serves as a primary driver in shaping the composition of mycorrhizal fungal communities during the development of ecosystems (Martínez-García et al., 2015 ). Fluctuations in soil phosphorus concentrations also impact the composition and richness of AM fungi. Under conditions of low soil phosphorus, plants may be more inclined to establish symbiotic relationships with AM fungi to enhance phosphorus acquisition efficiency (Neuenkamp et al., 2018 ). There are notable disparities in the diversity of AM fungi among the rhizosphere soil and the interior of the roots of Camellia oleifera, with the diversity within the roots being higher than that in the rhizosphere soil (Liu et al., 2021a ; Liu et al., 2021b ). Plant host preference and soil phosphorus content can lead to the formation of distinct AM fungi communities in both soil and within plant roots, with the interactive effects of these factors potentially influencing the growth characteristics of the plant host to a certain extent. Although there are many studies that confirm the productivity response of different crops to mycorrhizal inoculation, studies on the quality response of green tea Camellia sinensis are rare. The previous studies did not provide an analysis of the relationship of mycorrhizal species in the soil to phosphorus or to the quality characteristics of green tea in tropical and subtropical soils. This study aims to identify AM fungal genera that significantly impact the CQI of green tea by integrating the analysis of tea cultivars, available phosphorus content in soil, mycorrhizal colonization rates, and the characteristics of AM fungal communities in both rhizosphere soil and root systems, along with the catechin composition in fresh tea leaves. Materials and methods Plant material and growth conditions Camellia sinensis samples used in this study were obtained from the Chang'an Teaching and Research Base of Hunan Agricultural University (28° 09′ 13.07″N, 113°14′3.58″E), located in Huangxing Town, Changsha County, Hunan Province, China. The area was characterized by a subtropical monsoon climate with a brief cold season, an extended warm period, plentiful heat, and sufficient sunlight. The annual effective accumulated temperature is 5186.7°C, the mean annual temperature is 17.6°C, the frost-free period continues for 260 days, and the mean annual sunshine duration is 1510.9 hours. The studied tea cultivars included: Mingfeng (MF), Zhuye Qi (ZYQ), Taoyuan Daye (TYDY), Xiangfei Cui (XFC), Jianbo Huang (JBH), and Huangjin Tea No. 1 (HJC). The tested Camellia sinensis cultivars were uniform cultivation age (15 years) and had been cultivated under consistent agronomic practices. All of the evaluated Camellia sinensis have been growing properly and at a sufficient nutritional level under standardized cultivation conditions. Collection of tea root, rhizosphere soil, and leaf samples Three samples of each Camellia sinensis cultivar were selected in April 2023, and their foliage, roots, and rhizosphere soil were gathered during the springtime. Tea roots were extracted from the 0 and 30 cm soil layer using a shovel, and the soil on the root surface was gently removed with a brush, collected as rhizosphere soil. A portion of the tea root samples was stored in 60% ethanol for the determination of AM fungi colonization rates, while another portion was temporarily stored in liquid nitrogen for subsequent AM fungi sequencing. The rhizosphere soil that was collected was separated into two portions. The first portion was kept in liquid nitrogen in order to sequence AM fungi. The other portion was kept at indoor temperature, permitted to desiccate naturally, and then had its available phosphorus content examined. Fresh tea samples, including the terminal bud and the two leaves immediately below it, were collected from Camellia sinensis cultivars and promptly cryopreserved in liquid nitrogen before being shipped to the laboratory. The fresh tea leaves were freeze-dried for 48 hours and pulverized into fine powder for the determination of catechins and their components. Laboratory analyses The collected rhizosphere soil was air-dried and sifted, followed by the quantification of the available phosphorus content. The hydrochloric acid-ammonium fluoride (HCl-NH 4 F) method was utilized to quantify the available phosphorus content in the rhizosphere soil (Nawara et al., 2017 ). The content of catechins and their components (epicatechin, epicatechin gallate, epigallocatechin, gallocatechin gallate, and epigallocatechin gallate) in tea leaves was quantified using high-performance liquid chromatography (HPLC). The tea leaf powder, after freeze-drying, was extracted with a 70% methanol aqueous solution at 70°C in an aqueous bath. For the determination of catechin compounds, a C18 column was used, with the detection wavelength adjusted to 278 nm. Camellia sinensis roots preserved in ethanol were rinsed extensively with distilled water, and then transferred to a 10% KOH solution for decolorization in an aqueous bath.. Following this, the roots were immersed in a 0.05% Trypan Blue lactoglycerol solution for staining; subsequently, they were sectioned into approximately 1 cm lengths for microscopic evaluation of mycorrhizal colonization. (Koske and Gemma, 1989 ). For the determination of colonization rate, a cross-section method was employed under a microscope at 200× magnification (Wang et al., 2022). One axis of the microscope's crosshair was aligned parallel to the root, and the other axis was used to observe intersections with hyphae, arbuscules, and vesicles. Ten root segments were selected for each cultivar, and ten fields of view were observed for each root segment, resulting in a total of 100 fields of view (Mcgonigle et al., 1990 ). Prior to DNA extraction, the surfaces of tea root samples were sterilized using sodium hypochlorite and ethanol. The total DNA of AMF from the rhizosphere soil and root interior of Camellia sinensis was extracted using the hexadecyltrimethylammonium bromide (CTAB) method. The DNA of AMF was subjected to two rounds of specific PCR amplification. The first round utilized primers of AMV4.5NF and AMDGR, while the second round employed a customized primer set (forward primer: 5'-GTGARTCATCGAATCTTTG-3' and reverse primer: 5'-TCCTCCGCTTATTGATATGC-3'). Each PCR reaction, with a total volume of 25 µL, contained 50 µg of template DNA, 2.5 µL of 1 µM each of forward and reverse primers, and 12.5 µL of Phusion Hot Start Flex 2X Master Mix. Cycling parameters were optimized for each round of PCR. The PCR products were purified, quantified, and then assessed using an Agilent 2100 Bioanalyzer. Subsequently, sequencing was performed on a NovaSeq PE250 platform with the NovaSeq 6000 SP Reagent Kit. The resulting sequences were taxonomically annotated by alignment with the AMF database from the National Center for Biotechnology Information (NCBI). Bioinformatical analysis Upon completion of the sequencing run, the raw output data (RawData) was obtained. Utilizing overlap, the paired-end reads were assembled, followed by quality control and chimera filtering to yield high-quality cleaned data (CleanData). Subsequently, the Divisive Amplicon Denoising Algorithm (DADA2) was employed, which, instead of clustering based on sequence similarity, involved steps such as dereplication (equivalent to clustering at 100% identity) to derive representative sequences with single-nucleotide accuracy. This approach facilitated the construction of an OTU-like table using the concept of amplicon sequence variables (ASVs), culminating in the final ASV feature table and characteristic sequences. These data were then subjected to further analyses, including diversity analysis, taxonomic annotation, and differential analysis (Bolyen et al., 2019 ). Catechin quality index (CQI) and statistical analyses R version 4.3.3 was used to perform statistical analysis and visualizations. The averages and standard deviations from three biological replicates are used to show the experimental results. Using IBM SPSS Statistics 27, the Tukey's Honest Significant Difference test was employed to assess the statistical significance of the observed differences. Based on the catechin quality index (CQI), hierarchical clustering methods were applied to categorize the six tea cultivars into two levels: high catechin quality index (HCQI) with CQI > 484.26 and low catechin quality index (LCQI) with CQI < 484.26 (Kilel et al., 2013 ). CQI = (EGCG + ECG) / EGC*100), where EGCG, ECG, and EGC represent epigallocatechin gallate, epicatechin gallate, and epigallocatechin, respectively. Initially, variance analysis was employed to assess the disparities in mycorrhizal colonization rates of Camellia sinensis between the two CQI levels. A similarity analysis using the Adonis test from the "vegan" package was conducted to determine if there were significant differences in the AM fungi community structure between LCQI and HCQI. Principal coordinate analysis (PCoA) of the two AM fungi communities was visualized using the "PCoA" function from the "ggplot2" package in R. In the STAMP software, the raw sequencing ASV data from all cultivars was compared between the HCQI and LCQI groups to identify AM fungal genera that showed significant differences at the genus level. The "betapart" package was utilized to analyze sequencing data, investigating the causes of differences in the community structure of AM fungi in the rhizosphere soil and within the roots. The filtered ASVs from the AM fungi sequencing data encompassed both the rhizosphere soil and root samples of Camellia sinensis , excluding any with average relative abundances under 0.01% or those detected in less than 20% of the samples from the analysis. Using 'Gephi (v 0.10)', co-occurrence networks at the genus level of different CQI levels of Camellia sinensis rhizosphere soil and root-associated AM fungi were depicted. In microbial networks, positive cohesion refers to the mutually enhancing relationships between microbes, which may manifest as resource sharing, exchange of metabolic byproducts, or enhanced environmental adaptability. Negative cohesion reflects competitive or inhibitory relationships among microbial populations (Herren and McMahon, 2017 ). The stability of the rhizosphere soil and root-associated AM fungi networks was calculated by the ratio of the absolute values of positive to negative cohesion. In the R software suite, the "edgeR" package was utilized to filter specific ASVs. Subsequently, employing the LCQI as the control cohort, the selected ASVs were graphically represented on a volcano plot. This analytical approach was conducted to identify the significantly differential ASVs between the two CQI levels within the rhizosphere soil and root tissues of Camellia sinensis. A random forest analysis incorporating Amplicon Sequence Variants (ASVs) from AM fungi sequencing with the CQI was conducted to identify ASVs significantly associated with CQI. The Spearman correlation coefficient was used to conduct a correlation study assessing the associations among catechin quality, mycorrhizal colonization rates, the top four genera from AM fungal sequencing, and network stability, thereby pinpointing the key AM fungal characteristics significantly correlated with CQI. In R software, the "piecewise SEM" package was applied for visualizing and analyzing the structural equation model of composite variables, examining the intricate relationships among tea cultivars, available phosphorus in rhizosphere soil, mycorrhizal colonization rates, and the community characteristics of AM fungi in both rhizosphere soil and root tissues with catechin composition and the CQI. The optimal SEM model was determined using Fisher's C test, p-values, degrees of freedom (df), and Akaike Information Criteria (AIC). Results Catechin composition variability and hierarchical clustering results Significant variations in catechin composition were observed among different tea cultivars (Figs. 1 A to H). Specifically, the content of epicatechin gallate (ECG) in the TYDY was markedly higher than in the other cultivars, while the MF exhibited the lowest ECG content, with no significant differences in ECG content observed among the remaining cultivars (Fig. 1 C). The ZYQ exhibited a markedly higher level of epigallocatechin (EGC) relative to the other cultivars, with no significant differences in EGC content among the other cultivars (Fig. 1 D). The TYDY also had a significantly higher content of epigallocatechin gallate (EGCG) than the other cultivars (Fig. 1 E). The catechin quality index (CQI) is a crucial indicator for evaluating tea quality. Utilizing the results from the hierarchical clustering analysis, the six tested tea cultivars could be categorized into two groups: one group with a high catechin quality index (HCQI) above 484.26, which included MF, ZYQ, and TYDY, and another group with a low catechin quality index (LCQI) below 484.26, which included XFC, JBH, and HJC (Fig. 1 H). Available phosphorus content in rhizosphere soil and AM fungal colonization rate The present study indicates that there were substantial variations in the total colonization rate of AM fungi and the phosphorus availability within the rhizosphere soil among Camellia sinensis cultivars with different CQI levels. Specifically, the phosphorus availability within the rhizosphere soil of Camellia sinensis in the LCQI group markedly exceeded that of the HCQI group (Fig. 2 A), while the total colonization rate in the HCQI group was considerably more pronounced compared to the LCQI group (Fig. 2 B). Concurrently, the rates of both arbuscular and hyphal colonization were significantly higher in the HCQI group compared to those in the LCQI group (Fig. 2 C, 2 D). AM Fungal alpha diversity, community composition, and beta diversity The Shannon diversity index did not exhibit significant variations between the HCQI group and the LCQI group for both rhizosphere soil and the root samples (Fig. 3 A, B). However, the composition of AM fungal communities in the rhizosphere soil of HCQI and LCQI showed significant differences (Adonis: R 2 = 0.089, Pr = 0.030, Fig. 3 C). Similarly, the composition of AM fungal communities within the roots of HCQI and LCQI also exhibited significant differences (Adonis: R 2 = 0.112, Pr = 0.045, Fig. 3 D). The sequencing data obtained from the rhizosphere soil and roots of Camellia sinensis yielded ASVs belonging to nine distinct genera, with Paraglomus and Glomus being the predominant genera (Fig. 3 E). The relative abundance of Paraglomus notably rose in HCQI relative to LCQI (p = 0.037), while Glomus was significantly decreased (p = 0.013, Fig. 3 G, H). Characteristics of the AM fungi co-occurrence network Microbial co-occurrence networks are instrumental in elucidating interspecies relationships and the mechanisms of coexistence and interaction among different microbes within an ecosystem. Within the rhizosphere soil of Camellia sinensis , the co-occurrence network constructed from AM fungi exhibited a higher number of nodes for HCQI compared to LCQI, although the number of edges was less (Fig. 4 A, B). Within the roots of Camellia sinensis , the AM fungal co-occurrence network revealed a predominance of the Paraglomus genus in modules associated with HCQI, whereas the Glomus genus was more prevalent in those associated with LCQI (Fig. 4 C, D). The co-occurrence network’s stability, as inferred from the positive and negative cohesion within the microbial network, indicated that the network constructed by AM fungi in the rhizosphere soil for HCQI was significantly more stable than that for LCQI (Fig. 4 E). Screening for ASVs with significant impact on CQI Based on the edgeR differential analysis, ASVs were selected for volcano plot visualization in both the rhizosphere soil and within the rhiza of Camellia sinensis . The ASVs with significantly upregulated and downregulated expression in HCQI compared to LCQI were predominantly from the genera Paraglomus and Glomus (Fig. 5 A, B). In the Camellia sinensis’ rhizosphere soil, there was a higher number of significantly upregulated ASVs of Paraglomus in HCQI compared to Glomus , while the number of significantly downregulated ASVs of Glomus exceeded that of Paraglomus when compared to LCQI (Fig. 5 C). Consistent results were observed within the rhiza of Camellia sinensis (Fig. 5 D). Random forest analysis conducted with ASV data from both rhizosphere soil and rhiza against CQI indicated that these differentially expressed ASVs were still predominantly from the genera Paraglomus and Glomus (Fig. 5 E, F). Spearman correlation and piecewise structural equation model analysis To more effectively reveal the relationship between the green tea CQI and AM fungal colonization rate as well as community structure, we performed a correlation analysis of catechin components, CQI, available phosphorus content, and mycorrhizal colonization rate with the characteristics of AM fungal communities in rhizosphere soil and rhiza of Camellia sinensis . Additionally, a piecewise structural equation model (piecewise SEM) was utilized to elucidate the pathways by which AM fungi influence the CQI of green tea. Spearman's correlation analysis revealed that the content of EGCG and EGC, as well as the green tea CQI, were strongly positively correlated with total AMF colonization and arbuscular colonization (Fig. 6 A, B). The content of EGCG and the green tea CQI were both significantly negatively correlated with the rhizosphere soil’s available phosphorus content (Fig. 6 A, B). The correlation results with the AM fungal community traits within the rhizosphere soil indicated that the EGCG content was notably positively correlated with the diversity and network stability of the AM fungi in the rhizosphere soil; the EGC content was markedly positively correlated with network stability; and the CQI was notably negatively correlated only with the relative abundance of Glomus (Fig. 6 A). The Camellia sinensis’ rhiza correlation results showed that both the EGCG content and the CQI were significantly positively correlated with the Paraglomus and notably oppositely correlated with the relative abundance of Glomus , and the ECG content was positively correlated with network stability (Fig. 6 B). By constructing a piecewise SEM, we discovered that the influence of tea cultivar and rhizosphere soil available phosphorus on green tea CQI is primarily mediated through two distinct pathways (Fig. 6 C, D). One pathway is that the tea cultivars and the available phosphorus content in rhizosphere soil noticeably affect the colonization rate, which in turn influences the content of the EGCG, ECG, and EGC and subsequently significantly impacts the CQI (Fig. 6 C, D). The second pathway is that the tea cultivar and the rhizosphere soil available phosphorus significantly influence Rhiza AM fungal community characteristics, which then affect the CQI (Fig. 6 D). Discussion In the current study, nine AM fungal genera were identified within the rhizosphere soil and roots of six distinct tea cultivars. Paraglomus and Glomus were found to have the highest relative abundance across all cultivars, underscoring their prevalent role in tea gardens. It is noteworthy that the combined relative abundance of Paraglomus and Glomus within the roots of Camellia sinensis was further elevated compared to that in the rhizosphere soil. The previous study found that, under various agricultural management systems, tillage practices significantly impact the AM fungal populations under investigation (Douds Jr et al., 1995 ). The tea gardens in the present study are characteristic of organic management practices, with substantial organic fertilizers applied annually at year-end, which likely contributes to the abundance of Paraglomerales . Paraglomerales are more commonly found in organically managed soils, contrasting with conventional methods (Gosling et al., 2014 ). The tea cultivar and the rhizosphere soil’s available phosphorus content notably affect the mycorrhizal colonization rate and community structure of AM fungi in the roots of Camellia sinensis . The phenomenon that the soil phosphorus content is negatively correlated with the density of AM fungal spores is commonly observed (Carrenho, 1998 ; Santos and Carrenho, 2011 ). The lowest available soil phosphorus content (12.60 mg kg − 1 ) had the highest mycorrhizal colonization rate of 100%, while the tea garden with the highest available soil phosphorus content (28.17 mg kg − 1 ) had the lowest rate of mycorrhizal colonization (Sharma et al., 2013 ). This implies that in the phosphorus-rich soils, plants may reduce their dependence on mycorrhizal associations. In this study, the HCQI group’s mycorrhizal colonization rate was significantly higher than the LCQI. The available phosphorus content in the HCQI group ranged from 5.23 to 14.14 mg kg − 1 ; while for those with LCQI, it varied between 18.64 and 68.89 mg kg − 1 , showing a significant difference. These results are supportive of previous research. e.g., Santos and Carrenho ( 2011 ) and Qin et al. ( 2020 ). In the present study, the relative abundance of Glomus in the rhizosphere soil of Camellia sinensis at the HCQI group was not significantly different from that at the LCQI group. However, within the roots of Camellia sinensis at the LCQI group, which had a higher available phosphorus level, the relative abundance of Glomus was significantly higher than at the HCQI group (Fig. 3 E). Additionally, the relative abundance of Glomus within the roots showed a significantly positive correlation with the available phosphorus (AP) content, further indicating the competitive strength of Glomus under conditions of high soil AP. Camellia sinensis with a high CQI level, which corresponded to lower available phosphorus levels in the rhizosphere, showed a higher relative abundance of Paraglomus within the roots than in those with a low CQI. Furthermore, the CQI showed a markedly negative correlation with the AP content (Fig. 6 A, B). This also indicated that the significant differences in soil-available phosphorus (AP) content led to differences in the AM fungal community structure within the root of Camellia sinensis among varying CQI levels. Feng et al. sequenced AM fungi in subtropical citrus orchards in southern China and found a significant positive correlation between the relative abundance of Glomus and the available phosphorus (AP) and the ratio of AP to total phosphorus (TP), indicating its strong tolerance and competitiveness in agricultural soils with higher AP content (Feng et al., 2024 ). In savanna ecosystems, the rhizosphere soil’s relative abundance of Paraglomus was markedly negatively correlated with the content of available soil phosphorus (Touré et al., 2023 ). Although much research has linked the occurrence of Paraglomus to soil conditions, particularly soil phosphorus, their results are contradictory (Gosling et al., 2014 ). In the present study, Camellia sinensis with a higher level of CQI recruited more Paraglomus within their roots, while the lower level of CQI enriched more Glomus (Fig. 3 E). Crop type and soil physicochemical properties exert significant influence on mycorrhizal colonization rates and the dominant AM fungal genus, which may account for the diversity observed in AM fungal communities (Koskey et al., 2023 ; Zhang et al., 2024 ). The mycorrhizal colonization rate influenced the catechin composition, thereby affecting the CQI. The mycorrhizal colonization rate itself did not directly influence the CQI of green tea, but it may alter the quality of the tea through a series of indirect effects. The mutualistic association established between AM fungi and vegetation bestows multiple benefits upon the host plant, including the enhancement of photosynthesis, which can improve photosynthetic efficiency, increase biomass, and increase productivity (Baas and Kuiper, 1989 ; Black et al., 2000 ). Furthermore, the synthesis of catechins is to some extent reliant on the carbon source provided by Camellia sinensis through the photosynthetic fixation of atmospheric carbon dioxide (Xiang et al., 2021 ). The catechin compounds in green tea primarily consist of eight monomers: catechin (DL-C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (CG), epicatechin gallate (ECG), gallocatechin gallate (GCG), and epigallocatechin gallate (EGCG). Among these, EGCG ranges as the predominant, accounting for approximately 50–60% of the total catechin content. The CQI is determined from the content of EGCG, ECG, and EGC (Kilel et al., 2013 ). The present study showed that the cultivar of Camellia sinensis and the rhizosphere soil’s available phosphorus content have a big impact on the mycorrhizal colonization rate of Camellia sinensis (Fig. 6 C, D). There is also a strong positive relationship between the CQI and the total colonization rate (Fig. 6 A). This discovery suggested that the differences in Camellia sinensis cultivars and the rhizosphere soil’s available phosphorus content led to variations in mycorrhizal colonization rates, which may further influence the photosynthesis of Camellia sinensis . The changes in photosynthesis may, in turn, affect the composition of catechin compounds, ultimately impacting the CQI of green tea. Therefore, although the mycorrhizal colonization rate itself does not directly determine the CQI, it indirectly affects the quality of green tea by modulating photosynthesis and catechin synthesis. Mycorrhizal colonization can also modulate the concentrations of indigenous plant hormones, such as abscisic acid and jasmonic acid, which are integral to secondary plant metabolism (Adolfsson et al., 2017 ; Mandal et al., 2015 ). In addition to nutritional effects, mycorrhizal systems can also shape plant secondary metabolism through mechanisms unrelated to nutrient exchange, including modulating the plant's responsiveness to environmental challenges (Schweiger et al., 2014 ; Schweiger and Müller, 2015 ). In our study, the variations in the relative abundance of Paraglomus and Glomus contributing to the variation in green tea CQI may be attributed to their distinct carbon (C) requirements. Paraglomus typically forms smaller spores and has a lower carbon demand compared to Glomus species (Morton and Redecker, 2001 ; Qiu et al., 2021 ). This may imply that Paraglomus has a lower carbon demand from the plant or that it can more efficiently utilize the carbon resources provided by the host plant, whereas Glomus may be less efficient in utilizing the carbon allocated to it by the host plant's photosynthesis. The biosynthesis of catechins, which is contingent upon the carbon derived from the photosynthetic activity of Camellia sinensis , may be adversely affected if the plant cannot efficiently modulate its carbon distribution to satisfy the metabolic requirements of its associated Glomus . This could result in a scarcity of carbon resources, thereby impacting the production and accumulation of catechins. The spore morphology of Paraglomus is difficult to distinguish from that of Glomus ; however, there are significant differences in their phylogenetic positions at the molecular level and in their fatty acid compositions. This also suggests that they may have unique ecological adaptations and evolutionary histories (Morton and Redecker, 2001 ). Paraglomus typically possesses a more widespread extraradical mycelial system compared to Glomus (Treseder et al., 2018 ; Qiu et al., 2021 ). The increase of certain species of Paralomus within the plant may facilitate the acquisition of nutrients with poor mobility, such as phosphorus (P), by the plant (Dai et al., 2014 ; Gosling et al., 2014 ). Under conventional agricultural management systems, a high abundance of Paraglomus may have a positive impact on wheat production, whereas some species of the Glomus genus may have an adverse effect on wheat growth in organic agricultural frameworks (Dai et al., 2014 ). Paraglomerales , as AM fungi, serve as a principal mediator in the carbon cycle, transferring plant photosynthetic products to the soil microbial network, thereby promoting the distribution and cycling of carbon within the rhizosphere ecosystem (Hünninghaus et al., 2019 ). The growth suppression in plants by AM fungi could result from the host plant's inability to adjust its rate of carbon assimilation to compensate for the increased cost related to the carbon demands of the AM fungi (Koide and Elliott, 1989 ). Conclusion Although numerous studies have reported the benefits of AM fungi within agroecosystems, our understanding remains limited regarding the impact of AM fungi on CQI of the Camellia sinensis , particularly in green tea. In our study, Paraglomu s and Glomus were identified as the dominant AM fungal genera in the rhizosphere soil and the roots of Camellia sinensis in a red soil tea garden experimental site. The cultivar of Camellia sinensis and the rhizosphere soil’s available phosphorus level noticeably affected both the mycorrhizal colonization rate within the tea roots and the AM fungal community composition. The mycorrhizal colonization rate, in turn, influences the catechin composition in tea leaves, thereby affecting the green tea catechin quality index. Additionally, the differences in the AM fungal community composition significantly impacted the green tea catechin quality index. The concentration of available phosphorus in the rhizosphere soil is a primary influence in altering the mycorrhizal colonization rate within tea roots. Paraglomus may exhibit lower carbon requirements or more efficient utilization of the host Camellia sinensis ' s carbon resources compared to Glomus , further influencing the catechin quality index of the tea leaves. These results enhance our comprehension of the potential of Paraglomus in enhancing the catechin quality index of green tea. Future research could focus on inoculating Camellia sinensis with Paraglomus species of AM fungi to modulate the catechin composition in green tea, thereby improving its quality and offering a novel approach for cultivating premium green tea. Declarations Funding The authors thank supports by the Joint Fund for Regional (2024JJ7230), and the Hunan Provincial Science and Technology Innovation Major Program (2021NK1020). Author Contributions All authors contributed to the study conception and design. Pei Yuan: Writing - original draft, Data curation. YingZi Wang: Funding acquisition, Project administration. JianWei Peng: Methodology, Resources. Ya Chen: Investigation. JingJin Li: Investigation. Mamdouh A. Eissa: Writing – review and editing. GongWen Luo: Methodology, Software and Visualization. Chang Tian: Conceptualization, Methodology, Resources and Supervision. Declaration of Competing 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 Data will be made available on request. References Adolfsson, L., Nziengui, H., Abreu, I. N., Šimura, J., Beebo, A., Herdean, A., Moritz, T., Novák, O., Ljung, K., Schoefs, B., Spetea, C (2017) Enhanced secondary-and hormone metabolism in leaves of arbuscular mycorrhizal Medicago truncatula. Plant Physiology, 175(1), 392-411. Ahammed, G. J., Li, X (2022) Hormonal regulation of health-promoting compounds in tea (Camellia sinensis L.). Plant Physiology and Biochemistry, 185, 390-400. Baas, R., Kuiper, D (1989) Effects of vesicular‐arbuscular mycorrhizal colonization and phosphate on Plantago major ssp. pleiosperma in relation to internal cytokinin concentrations. Physiologia plantarum, 76(2), 211-215. Black, K. G., Mitchell, D. T., Osborne, B. A (2000) Effect of mycorrhizal‐enhanced leaf phosphate status on carbon partitioning, translocation and photosynthesis in cucumber. Plant, Cell & Environment, 23(8), 797-809. Bolyen, E., Rideout, J. R., Dillon, M. R., et al., (2019) Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nature biotechnology, 37(8), 852-857. Carrenho, R (1998) Influência de diferentes espécies de plantas hospedeiras e fatores edáficos no desenvolvimento de fungos micorrízicos arbusculares (FMA). Rio Claro, Tese de Doutorado. Universidade Estadual Paulista. Chen, W., Ye, T., Sun, Q., Niu, T., Zhang, J (2021) Arbuscular mycorrhizal fungus alters root system architecture in Camellia sinensis L. as revealed by RNA-Seq analysis. Frontiers in Plant Science, 12, 777357. Dai, M., Hamel, C., Bainard, L. D., Arnaud, M. S., Grant, C. A., Lupwayi, N. Z., Malhi, S. S., Lemke, R (2014) Negative and positive contributions of arbuscular mycorrhizal fungal taxa to wheat production and nutrient uptake efficiency in organic and conventional systems in the Canadian prairie. Soil Biology and Biochemistry, 74, 156-166. Douds Jr, D. D., Galvez, L., Janke, R. R., Wagoner, P (1995) Effect of tillage and farming system upon populations and distribution of vesicular-arbuscular mycorrhizal fungi. Agriculture, ecosystems & environment, 52(2-3), 111-118. Drew, L (2019) The growth of tea. Nature, 566(7742), S2-S2. Feng, Z., Pan, C., Qin, Y., Xie, X., Liu, X., Chen, M., Zhang, W., Zhu, H., Yao, Q (2024) Natural grass coverage enriches arbuscular mycorrhizal fungal communities in subtropical citrus orchards through the regulation of Glomus on a regional scale. Applied Soil Ecology, 195, 105211. Gao, X., Liu, Y., Liu, C., Guo, C., Zhang, Y., Ma, C., Duan, X (2023). Individual and combined effects of arbuscular mycorrhizal fungi and phytohormones on the growth and physiobiochemical characteristics of tea cutting seedlings. Frontiers in Plant Science, 14, 1140267. Gosling, P., Proctor, M., Jones, J., Bending, G. D (2014) Distribution and diversity of Paraglomus spp. in tilled agricultural soils. Mycorrhiza, 24, 1-11. Herren, C. M., McMahon, K. D (2017) Cohesion: a method for quantifying the connectivity of microbial communities. The ISME Journal, 11(11), 2426-2438. Hung, Y. T., Chen, P. C., Chen, R. L., Cheng, T. J (2010) Sequential determination of tannin and total amino acid contents in tea for taste assessment by a fluorescent flow-injection analytical system. Food Chemistry, 118(3), 876-881. Hünninghaus, M., Dibbern, D., Kramer, S., Koller, R., Pausch, J., Schloter-Hai, B., Urich, T., Kandeler, E., Bonkowski, M., Lueders, T (2019) Disentangling carbon flow across microbial kingdoms in the rhizosphere of maize. Soil Biology and Biochemistry, 134, 122-130. Jugran, A. K., Bahukhandi, A., Dhyani, P., Bhatt, I. D., Rawal, R. S., Nandi, S. K., Palni, L. M. S(2015) The effect of inoculation with mycorrhiza: AM on growth, phenolics, tannins, phenolic composition and antioxidant activity in Valeriana jatamansi Jones. Journal of soil science and plant nutrition, 15(4), 1036-1049. Kc, S., Long, L., Zhang, Q., Ni, K., Ma, L., Ruan, J (2022) Effect of interactions between phosphorus and light intensity on metabolite compositions in tea cultivar Longjing43. International Journal of Molecular Sciences, 23(23), 15194. Kilel, E. C., Faraj, A. K., Wanyoko, J. K., Wachira, F. N., Mwingirwa, V (2013) Green tea from purple leaf coloured tea clones in Kenya-their quality characteristics. Food Chemistry, 141(2), 769-775. Koide, R., Elliott, G (1989) Cost, benefit and efficiency of the vesicular-arbuscular mycorrhizal symbiosis. Functional Ecology, 252-255. Koske, R. E., Gemma, J. N (1989) A modified procedure for staining roots to detect VA mycorrhizas. Mycological Research, 92(4), 486-488. Koskey, G., Avio, L., Turrini, A., Sbrana, C., Bàrberi, P (2023) Durum wheat-lentil relay intercropping enhances soil mycorrhizal activity but does not alter structure of arbuscular mycorrhizal fungal community within roots. Agriculture, Ecosystems & Environment, 357, 108696. Lin, Z. H., Qi, Y. P., Chen, R. B., Zhang, F. Z., Chen, L. S (2012) Effects of phosphorus supply on the quality of green tea. Food Chemistry, 130(4), 908-914. Liu, R. C., Xiao, Z. Y., Hashem, A., Abd_Allah, E. F., Xu, Y. J., Wu, Q. S (2021a) Unraveling the interaction between arbuscular mycorrhizal fungi and Camellia plants. Horticulturae, 7(9), 322. Liu, R. C., Xiao, Z. Y., Hashem, A., Abd_Allah, E. F., Wu, Q. S (2021b) Mycorrhizal fungal diversity and its relationship with soil properties in Camellia oleifera. Agriculture, 11(6), 470. Mandal, S., Upadhyay, S., Wajid, S., Ram, M., Jain, D. C., Singh, V. P., Abdin, M. Z., Kapoor, R (2015) Arbuscular mycorrhiza increase artemisinin accumulation in Artemisia annua by higher expression of key biosynthesis genes via enhanced jasmonic acid levels. Mycorrhiza, 25, 345-357. Martínez‐García, L. B., Richardson, S. J., Tylianakis, J. M., Peltzer, D. A., Dickie, I. A (2015) Host identity is a dominant driver of mycorrhizal fungal community composition during ecosystem development. New Phytologist, 205(4), 1565-1576. McGonigle, T. P., Miller, M. H., Evans, D. G., Fairchild, G. L., Swan, J. A (1990) A new method which gives an objective measure of colonization of roots by vesicular—arbuscular mycorrhizal fungi. New phytologist, 115(3), 495-501. Morton, J. B., Redecker, D (2001) Two new families of Glomales, Archaeosporaceae and Paraglomaceae, with two new genera Archaeospora and Paraglomus, based on concordant molecular and morphological characters. Mycologia, 93(1), 181-195. Nawara, S., Van Dael, T., Merckx, R., Amery, F., Elsen, A., Odeurs, W., Vandendriessche, H., Mcgrath, S.,Roisin, C., Jouany, Pellerin, S., Denoroy, P., Eichler-Löbermann, B., Börjesson, G., Goos, P., Akkermans, W., Smolders, E (2017) A comparison of soil tests for available phosphorus in long‐term field experiments in Europe. European Journal of Soil Science, 68(6), 873-885. Neuenkamp, L., Moora, M., Öpik, M., Davison, J., Gerz, M., Männistö, M., Jairus, T., Vasar, M., Zobel, M (2018) The role of plant mycorrhizal type and status in modulating the relationship between plant and arbuscular mycorrhizal fungal communities. New Phytologist, 220(4), 1236-1247. Qin, Z., Zhang, H., Feng, G., Christie, P., Zhang, J., Li, X., Gai, J (2020) Soil phosphorus availability modifies the relationship between AM fungal diversity and mycorrhizal benefits to maize in an agricultural soil. Soil Biology and Biochemistry, 144, 107790. Qiu, Y., Guo, L., Xu, X., Zhang, L., Zhang, K., Chen, M., Zhao, Y., Burkey, K. O., Shew, H. D., Zobel, R. W., Zhang, Y., Hu, S (2021) Warming and elevated ozone induce tradeoffs between fine roots and mycorrhizal fungi and stimulate organic carbon decomposition. Science advances, 7(28), eabe9256. Santos, F. E. F. D., Carrenho, R (2011) Diversidade de fungos micorrízicos arbusculares em remanescente florestal impactado (Parque Cinqüentenário-Maringá, Paraná, Brasil). Acta Botanica Brasilica, 25, 508-516. Schweiger, R., Müller, C (2015) Leaf metabolome in arbuscular mycorrhizal symbiosis. Current opinion in plant biology, 26, 120-126. Schweiger, R., Baier, M. C., Müller, C (2014) Arbuscular mycorrhiza-induced shifts in foliar metabolism and photosynthesis mirror the developmental stage of the symbiosis and are only partly driven by improved phosphate uptake. Molecular Plant-Microbe Interactions, 27(12), 1403-1412. Sharma, C., Gupta, R. K., Pathak, R. K., Choudhary, K. K (2013) Seasonal colonization of arbuscular mycorrhiza fungi in the roots of Camellia sinensis (tea) in different tea gardens of India. International Scholarly Research Notices, 2013(1), 593087. Touré, G. P. T., Koné, A. W., Nandjui, J., Ebou, A. E., Otinga, A. N., Maïga, A. A., Kouadjo, C. G. Z., Thio, S., Zézé, A (2023) Changes in arbuscular mycorrhizal fungal communities, mycorrhizal soil infectivity, and phosphorus availability under Chromolaena odorata (Asteraceae) invasions in a West-African forest-savanna ecotone. Mycorrhiza, 33(4), 257-275. Treseder, K. K., Allen, E. B., Egerton‐Warburton, L. M., Hart, M. M., Klironomos, J. N., Maherali, H., Tedersoo, L (2018) Arbuscular mycorrhizal fungi as mediators of ecosystem responses to nitrogen deposition: A trait‐based predictive framework. Journal of Ecology, 106(2), 480-489. Wan, C., Ouyang, J., Li, M., Rengasamy, K. R., Liu, Z (2024) Effects of green tea polyphenol extract and epigallocatechin-3-O-gallate on diabetes mellitus and diabetic complications: Recent advances. Critical reviews in food science and nutrition, 64(17), 5719-5747. Wang, N., Wang, Y., Zhang, X., Wu, Y., Zhang, L., Liu, G., Fu, J., Li, X., Mu, D., Li, Z (2024) Elevated Ozone Reduces the Quality of Tea Leaves but May Improve the Resistance of Tea Plants. Plants, 13(8), 1108. Wang, S. Y., Wei, H., Chen, K. Y., Dong, Q., Ji, B. M., Zhang, J (2021) Practical methods for arbuscular mycorhizal fungal spore densty, hyphal density and colonization rate of AMF. Bio-Protoc. J, 101, e2104253. Xiang, P., Zhu, Q., Tukhvatshin, M., Cheng, B., Tan, M., Liu, J., Wang, X., Huang, J., Gao, S., Lin, D., Zhang, Y., Wu, L., Lin, J., 2021. Light control of catechin accumulation is mediated by photosynthetic capacity in tea plant (Camellia sinensis). BMC Plant Biology, 21, 1-13. Xin, W., Zhang, J., Yu, Y., Tian, Y., Li, H., Chen, X., Li, W., Liu, Y., Lu, T., He, B., Xiong, Y., Yang, Z., Xu, T., Tang, W (2024) Root microbiota of tea plants regulate nitrogen homeostasis and theanine synthesis to influence tea quality. Current Biology, 34(4), 868-880. Yang, Y., Ke, J. P., Yang, Z., Chen, C. H., Li, J. Y., Yu, J. Y., Zhang, Y. X., Bao, G. H (2024) Green tea hydroxycinnamoylated catechins extend lifespan and attenuate Aβ-induced paralysis of Caenorhabditis elegans via anti-oxidation and peptides dis-aggregation. Industrial Crops and Products, 212, 118390. Zhang, J. L., Song, J., Kang, Y. H., Wen, Y. Y., Nong, Y. J., Wang, Q., Qin, X. J., Chen,T. S., Li, Y. R (2024) The Community of Arbuscular Mycorrhizal Fungi in Sugarcane Rhizosphere Soils in Guangxi, China. Sugar Tech, 26(1), 131-142. Additional Declarations No competing interests reported. Supplementary Files floatimage1.png Graphical abstract Cite Share Download PDF Status: Published Journal Publication published 20 Feb, 2025 Read the published version in Mycorrhiza → Version 1 posted Editorial decision: Revision requested 12 Jan, 2025 Reviews received at journal 19 Dec, 2024 Reviewers agreed at journal 21 Nov, 2024 Reviewers agreed at journal 18 Nov, 2024 Reviewers invited by journal 11 Nov, 2024 Editor assigned by journal 11 Nov, 2024 Submission checks completed at journal 11 Nov, 2024 First submitted to journal 09 Nov, 2024 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. 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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-5424269","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":381102153,"identity":"372f191a-66a8-4f0e-b203-72a7ad0b6c26","order_by":0,"name":"Pei Yuan","email":"","orcid":"","institution":"Hunan Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Pei","middleName":"","lastName":"Yuan","suffix":""},{"id":381102155,"identity":"2b05f9b3-1642-415a-9669-b8f490176024","order_by":1,"name":"Yingzi Wang","email":"","orcid":"","institution":"Hunan Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Yingzi","middleName":"","lastName":"Wang","suffix":""},{"id":381102156,"identity":"9d1196b9-ff4b-4ef9-b026-b021563eed76","order_by":2,"name":"Jianwei Peng","email":"","orcid":"","institution":"Hunan Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Jianwei","middleName":"","lastName":"Peng","suffix":""},{"id":381102159,"identity":"9f3473d0-1172-48a9-a751-0e23b6205864","order_by":3,"name":"Ya Chen","email":"","orcid":"","institution":"Hunan Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Ya","middleName":"","lastName":"Chen","suffix":""},{"id":381102160,"identity":"abb867ba-8f3d-4064-afce-14ffb3693b9e","order_by":4,"name":"Jinjing Li","email":"","orcid":"","institution":"Hunan Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Jinjing","middleName":"","lastName":"Li","suffix":""},{"id":381102161,"identity":"12a317da-bb4e-48fe-849d-fd72af5e00aa","order_by":5,"name":"Mamdouh A. Eissa","email":"","orcid":"","institution":"Assiut University","correspondingAuthor":false,"prefix":"","firstName":"Mamdouh","middleName":"A.","lastName":"Eissa","suffix":""},{"id":381102162,"identity":"eee90585-5ae6-4e43-a6d1-3c75c3a5dba7","order_by":6,"name":"Gongwen Luo","email":"","orcid":"","institution":"Hunan Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Gongwen","middleName":"","lastName":"Luo","suffix":""},{"id":381102163,"identity":"a64bcd2b-be90-4279-acf1-78267b618015","order_by":7,"name":"Chang Tian","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAv0lEQVRIiWNgGAWjYDACCQaGA0BSjp+Z+eADIrUwg7RYGEu2syUbEK0FCCoSN5znMRMgSgf/7P6DB37ukGDcfJjBjIGhxiaasCV3DjMc7D0jwWx2mCHtAcOxtNwGQloMJJIZDvC2SbABtRw3YGw4TJyWg3/bJHiMmxnbJIjWchhoi4QBMzMbcVokbiQbHJZtkzCQOMzGbJBAjF/4ZyQ+/vi2ra6+v//8xwcfamwIa0EFCaQpHwWjYBSMglGACwAAHwc72actesAAAAAASUVORK5CYII=","orcid":"","institution":"Hunan Agricultural University","correspondingAuthor":true,"prefix":"","firstName":"Chang","middleName":"","lastName":"Tian","suffix":""}],"badges":[],"createdAt":"2024-11-10 04:53:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5424269/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5424269/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00572-025-01185-9","type":"published","date":"2025-02-20T15:57:05+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":70129536,"identity":"b9f5a306-044b-4dc0-80f8-429e281cddbb","added_by":"auto","created_at":"2024-11-28 15:48:38","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":448969,"visible":true,"origin":"","legend":"\u003cp\u003eDifferential catechin composition among various tea cultivars and the hierarchical clustering results based on CQI. All results are means±standard error (\u003cem\u003en = 3\u003c/em\u003e). Different letters on the bar chart indicate statistically significant differences at the\u003cem\u003e p \u0026lt; 0.05 \u003c/em\u003elevel.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/23d5bdc971acf671020688f4.png"},{"id":70129543,"identity":"4399e9aa-846c-4178-8bd0-aacd6cf0df8d","added_by":"auto","created_at":"2024-11-28 15:48:38","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":130763,"visible":true,"origin":"","legend":"\u003cp\u003eDifferential available phosphorus content in rhizosphere soil and AM fungal colonization rates in \u003cem\u003eCamellia sinensis\u003c/em\u003e across varying CQI levels. All results are means ± standard error. Independent sample t-test was performed to evaluate the significant difference between HCQI and LCQI (\u003cem\u003en = 9\u003c/em\u003e). Different letters on the bar chart indicate statistically significant differences at the \u003cem\u003ep \u0026lt; 0.05\u003c/em\u003e level.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/199df1deabd6ba095361794d.png"},{"id":70130632,"identity":"763afd8a-9bf5-4fc5-baf7-7feeb5eac2c9","added_by":"auto","created_at":"2024-11-28 15:56:38","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":353079,"visible":true,"origin":"","legend":"\u003cp\u003eVariations in AM fungal diversity within rhizosphere soil and rhiza of \u003cem\u003eCamellia sinensis\u003c/em\u003e across different CQI levels. (A, B) AM fungal alpha diversity. (C, D) AM fungal beta diversity. (E, F) AM fungal community composition at the genus level. (G, H) AM fungal beta diversity decomposition. Independent sample t-test was performed to evaluate the significant difference between HCQI and LCQI (\u003cem\u003en\u003c/em\u003e = 9).\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/ffc2514d602f76d65091a423.png"},{"id":70129539,"identity":"6cecb1e9-3019-43d1-aba2-f39f9333b4bf","added_by":"auto","created_at":"2024-11-28 15:48:38","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":493574,"visible":true,"origin":"","legend":"\u003cp\u003eAt the genus level, the structure and characteristics of AM fungal co-occurrence networks in the rhizosphere soil and rhiza of \u003cem\u003eCamellia sinensis\u003c/em\u003e across different CQI levels. (A-E) AM fungal co-occurrence networks. (E, F) Network stability of AM fungal co-occurrence networks in the rhizosphere soil and rhiza. (G) AM Co-occurrence Network Metrics. Independent sample t-test was performed to evaluate the significant difference between HCQI and LCQI (\u003cem\u003en\u003c/em\u003e = 9).\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/5ac167f35bd61ba9bcce5774.png"},{"id":70129538,"identity":"9296d10e-f73f-41df-ab2d-41bcc6161f20","added_by":"auto","created_at":"2024-11-28 15:48:38","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":374741,"visible":true,"origin":"","legend":"\u003cp\u003eASVs in rhizosphere soil and rhiza significantly impacting the CQI of \u003cem\u003eCamellia sinensis\u003c/em\u003e. (A, B) Volcano plots constructed from ASVs identified through differential analysis using the edgeR package. (C, D) Statistical analysis of the number of ASVs at the genus level of arbuscular mycorrhizal fungi, categorized as significantly upregulated and downregulated, based on the volcano plot. （E, F）Random forest results for ASVs significantly affecting the CQI. In the legend, different colors represent various AM fungal genera.\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/2383dd4467bcfdaf4ea02a40.png"},{"id":70129542,"identity":"8c6a9198-f4ee-458b-a576-658bd2be70a8","added_by":"auto","created_at":"2024-11-28 15:48:38","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":389420,"visible":true,"origin":"","legend":"\u003cp\u003eSpearman’s correlation analysis among catechin composition, CQI, rhizosphere soil available phosphorus, mycorrhizal colonization rate, and arbuscular mycorrhizal fungal community characteristics and an associated piecewise structural equation model approach. (A, B) Spearman correlation analysis. (C, D) Piecewise structural equation model analysis. In the piecewise SEM, solid lines represent significant paths, while dashed lines indicate non-significant paths; the numbers on the lines represent the path coefficients; the R-squared (\u003cem\u003eR\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e) on the box signifies the goodness-of-fit of the model for that particular data segment; the numbers following the indicators within the box denote the regression coefficients of the indicators with CQI. The numbers in the grid represent the correlation coefficients. *, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05, **, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.01, and ***, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001.\u003c/p\u003e","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/4ce6d7d74a839680d09a5fb1.png"},{"id":77052498,"identity":"38f45011-30f7-46f3-bea0-fadb45ad85d8","added_by":"auto","created_at":"2025-02-24 16:11:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2734185,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/1c87a46f-323b-4d66-bae2-1142f551e386.pdf"},{"id":70129537,"identity":"389dff9a-0870-42d8-b7c1-7fb5fde7c48b","added_by":"auto","created_at":"2024-11-28 15:48:38","extension":"png","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":332359,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGraphical abstract\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-5424269/v1/6d10f63034a726d6cb816926.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Paraglomus and Glomus Arbuscular Mycorrhizal Fungi induce the Green Tea Catechin Quality Index and Phosphorus bioavailability in Tropical soils","fulltext":[{"header":"Highlights","content":"\u003cul\u003e\n \u003cli\u003eArbuscular mycorrhizal (AM) influenced the catechin quality index (CQI) of green tea.\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eParaglomus\u003c/em\u003e and \u003cem\u003eGlomus\u003c/em\u003e were the dominant AM fungal genera.\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eParaglomus\u003c/em\u003e contributed positively to the enhancement of CQI in green tea.\u003c/li\u003e\n \u003cli\u003eRhizospheric phosphorus levels markedly affected tea plant mycorrhizal colonization.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Introduction","content":"\u003cp\u003e \u003cem\u003eCamellia sinensis\u003c/em\u003e, a crop of significant economic importance originating from China, has now been widely cultivated in over 60 countries worldwide (Drew, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The \u003cem\u003eCamellia sinensis\u003c/em\u003e shoots and leaves, when processed into tea, contain a variety of secondary metabolites beneficial to human health, including catechins and amino acids (Ahammed et al., 2022). These secondary metabolites are crucial in determining the quality of the tea. Predominant among the polyphenols in green tea, catechins exhibit distinctive astringent qualities, encompassing bitterness and astringency, appealing to a diverse consumer palate (Hung et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). In comparison with other categories of tea, green tea is particularly abundant in natural catechins, which include epicatechin (EC), catechin (DL-C), epicatechin (ECG), epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG) (Kilel et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Epigallocatechin gallate (EGCG), a major and beneficial bioactive compound in green tea, exhibits a multitude of effects, including antimicrobial, antiviral, cardiovascular protection, and antitumor activities (Wan et al., 2022; Yang et al., \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Catechin Quality Index is a widely recognized metric for assessing green tea quality, directly associated with its delicacy and superior attributes. Its calculation method is the sum of the contents of EGCG and ECG divided by the content of EGC, multiplied by 100 (Kilel et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Wang et al., \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). The excellence of fresh tea leaves stems not only from the tea varieties but also from the interplay of soil characteristics and the soil's microbial community (Xin et al., \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSoil phosphorus is crucial for the growth of Camellia sinensis, influencing the biosynthesis of catechins and consequently affecting the quality of green tea. Phosphorus deficiency is associated with decreased levels of total phenolics and amino acids in tea leaves, consequently impairing the taste characteristics of tea infusions (Lin et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Additionally, the reciprocal influences of phosphorus and photosynthetic photon flux density on catechins are intricate, with phosphorus status playing a crucial part in modulating the impact of light exposure on tea quality (Kc et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). AM fungi are beneficial soil microbes that establish symbiotic associations with plants, aiding the assimilation of critical nutrients like nitrogen and phosphorus from the soil in return for carbon sourced from photosynthesis (Gao et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Neuenkamp et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Tea production is predominantly concentrated in China and India, and a variety of AM fungi species have been discovered in tea plantations across these nations (Liu et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2021a\u003c/span\u003e). AM fungi, by establishing a mutually beneficial association with the root systems of \u003cem\u003eCamellia sinensis\u003c/em\u003e, enhance the absorption of water and nutrients, strengthen the plants' tolerance to stress, and may positively influence the quality of the tea leaves (Chen et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Inoculation with AM fungi significantly enhanced the levels of catechins, a group of phenolic compounds, with both the aerial and root tissues of \u003cem\u003eValeriana jatamansi\u003c/em\u003e (Jugran et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2015\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe identity of the plant host serves as a primary driver in shaping the composition of mycorrhizal fungal communities during the development of ecosystems (Mart\u0026iacute;nez-Garc\u0026iacute;a et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Fluctuations in soil phosphorus concentrations also impact the composition and richness of AM fungi. Under conditions of low soil phosphorus, plants may be more inclined to establish symbiotic relationships with AM fungi to enhance phosphorus acquisition efficiency (Neuenkamp et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). There are notable disparities in the diversity of AM fungi among the rhizosphere soil and the interior of the roots of Camellia oleifera, with the diversity within the roots being higher than that in the rhizosphere soil (Liu et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2021a\u003c/span\u003e; Liu et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2021b\u003c/span\u003e). Plant host preference and soil phosphorus content can lead to the formation of distinct AM fungi communities in both soil and within plant roots, with the interactive effects of these factors potentially influencing the growth characteristics of the plant host to a certain extent.\u003c/p\u003e \u003cp\u003eAlthough there are many studies that confirm the productivity response of different crops to mycorrhizal inoculation, studies on the quality response of green tea \u003cem\u003eCamellia sinensis\u003c/em\u003e are rare. The previous studies did not provide an analysis of the relationship of mycorrhizal species in the soil to phosphorus or to the quality characteristics of green tea in tropical and subtropical soils. This study aims to identify AM fungal genera that significantly impact the CQI of green tea by integrating the analysis of tea cultivars, available phosphorus content in soil, mycorrhizal colonization rates, and the characteristics of AM fungal communities in both rhizosphere soil and root systems, along with the catechin composition in fresh tea leaves.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003ePlant material and growth conditions\u003c/p\u003e \u003cp\u003e \u003cem\u003eCamellia sinensis\u003c/em\u003e samples used in this study were obtained from the Chang'an Teaching and Research Base of Hunan Agricultural University (28\u0026deg; 09\u0026prime; 13.07\u0026Prime;N, 113\u0026deg;14\u0026prime;3.58\u0026Prime;E), located in Huangxing Town, Changsha County, Hunan Province, China. The area was characterized by a subtropical monsoon climate with a brief cold season, an extended warm period, plentiful heat, and sufficient sunlight. The annual effective accumulated temperature is 5186.7\u0026deg;C, the mean annual temperature is 17.6\u0026deg;C, the frost-free period continues for 260 days, and the mean annual sunshine duration is 1510.9 hours. The studied tea cultivars included: Mingfeng (MF), Zhuye Qi (ZYQ), Taoyuan Daye (TYDY), Xiangfei Cui (XFC), Jianbo Huang (JBH), and Huangjin Tea No. 1 (HJC). The tested \u003cem\u003eCamellia sinensis\u003c/em\u003e cultivars were uniform cultivation age (15 years) and had been cultivated under consistent agronomic practices. All of the evaluated \u003cem\u003eCamellia sinensis\u003c/em\u003e have been growing properly and at a sufficient nutritional level under standardized cultivation conditions.\u003c/p\u003e \u003cp\u003eCollection of tea root, rhizosphere soil, and leaf samples\u003c/p\u003e \u003cp\u003eThree samples of each \u003cem\u003eCamellia sinensis\u003c/em\u003e cultivar were selected in April 2023, and their foliage, roots, and rhizosphere soil were gathered during the springtime. Tea roots were extracted from the 0 and 30 cm soil layer using a shovel, and the soil on the root surface was gently removed with a brush, collected as rhizosphere soil. A portion of the tea root samples was stored in 60% ethanol for the determination of AM fungi colonization rates, while another portion was temporarily stored in liquid nitrogen for subsequent AM fungi sequencing. The rhizosphere soil that was collected was separated into two portions. The first portion was kept in liquid nitrogen in order to sequence AM fungi. The other portion was kept at indoor temperature, permitted to desiccate naturally, and then had its available phosphorus content examined. Fresh tea samples, including the terminal bud and the two leaves immediately below it, were collected from \u003cem\u003eCamellia sinensis\u003c/em\u003e cultivars and promptly cryopreserved in liquid nitrogen before being shipped to the laboratory. The fresh tea leaves were freeze-dried for 48 hours and pulverized into fine powder for the determination of catechins and their components.\u003c/p\u003e \u003cp\u003eLaboratory analyses\u003c/p\u003e \u003cp\u003eThe collected rhizosphere soil was air-dried and sifted, followed by the quantification of the available phosphorus content. The hydrochloric acid-ammonium fluoride (HCl-NH\u003csub\u003e4\u003c/sub\u003eF) method was utilized to quantify the available phosphorus content in the rhizosphere soil (Nawara et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). The content of catechins and their components (epicatechin, epicatechin gallate, epigallocatechin, gallocatechin gallate, and epigallocatechin gallate) in tea leaves was quantified using high-performance liquid chromatography (HPLC). The tea leaf powder, after freeze-drying, was extracted with a 70% methanol aqueous solution at 70\u0026deg;C in an aqueous bath. For the determination of catechin compounds, a C18 column was used, with the detection wavelength adjusted to 278 nm. \u003cem\u003eCamellia sinensis\u003c/em\u003e roots preserved in ethanol were rinsed extensively with distilled water, and then transferred to a 10% KOH solution for decolorization in an aqueous bath.. Following this, the roots were immersed in a 0.05% Trypan Blue lactoglycerol solution for staining; subsequently, they were sectioned into approximately 1 cm lengths for microscopic evaluation of mycorrhizal colonization. (Koske and Gemma, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e1989\u003c/span\u003e). For the determination of colonization rate, a cross-section method was employed under a microscope at 200\u0026times; magnification (Wang et al., 2022). One axis of the microscope's crosshair was aligned parallel to the root, and the other axis was used to observe intersections with hyphae, arbuscules, and vesicles. Ten root segments were selected for each cultivar, and ten fields of view were observed for each root segment, resulting in a total of 100 fields of view (Mcgonigle et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e1990\u003c/span\u003e).\u003c/p\u003e \u003cp\u003ePrior to DNA extraction, the surfaces of tea root samples were sterilized using sodium hypochlorite and ethanol. The total DNA of AMF from the rhizosphere soil and root interior of \u003cem\u003eCamellia sinensis\u003c/em\u003e was extracted using the hexadecyltrimethylammonium bromide (CTAB) method. The DNA of AMF was subjected to two rounds of specific PCR amplification. The first round utilized primers of AMV4.5NF and AMDGR, while the second round employed a customized primer set (forward primer: 5'-GTGARTCATCGAATCTTTG-3' and reverse primer: 5'-TCCTCCGCTTATTGATATGC-3'). Each PCR reaction, with a total volume of 25 \u0026micro;L, contained 50 \u0026micro;g of template DNA, 2.5 \u0026micro;L of 1 \u0026micro;M each of forward and reverse primers, and 12.5 \u0026micro;L of Phusion Hot Start Flex 2X Master Mix. Cycling parameters were optimized for each round of PCR. The PCR products were purified, quantified, and then assessed using an Agilent 2100 Bioanalyzer. Subsequently, sequencing was performed on a NovaSeq PE250 platform with the NovaSeq 6000 SP Reagent Kit. The resulting sequences were taxonomically annotated by alignment with the AMF database from the National Center for Biotechnology Information (NCBI).\u003c/p\u003e \u003cp\u003eBioinformatical analysis\u003c/p\u003e \u003cp\u003eUpon completion of the sequencing run, the raw output data (RawData) was obtained. Utilizing overlap, the paired-end reads were assembled, followed by quality control and chimera filtering to yield high-quality cleaned data (CleanData). Subsequently, the Divisive Amplicon Denoising Algorithm (DADA2) was employed, which, instead of clustering based on sequence similarity, involved steps such as dereplication (equivalent to clustering at 100% identity) to derive representative sequences with single-nucleotide accuracy. This approach facilitated the construction of an OTU-like table using the concept of amplicon sequence variables (ASVs), culminating in the final ASV feature table and characteristic sequences. These data were then subjected to further analyses, including diversity analysis, taxonomic annotation, and differential analysis (Bolyen et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2019\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCatechin quality index (CQI) and statistical analyses\u003c/p\u003e \u003cp\u003eR version 4.3.3 was used to perform statistical analysis and visualizations. The averages and standard deviations from three biological replicates are used to show the experimental results. Using IBM SPSS Statistics 27, the Tukey's Honest Significant Difference test was employed to assess the statistical significance of the observed differences. Based on the catechin quality index (CQI), hierarchical clustering methods were applied to categorize the six tea cultivars into two levels: high catechin quality index (HCQI) with CQI\u0026thinsp;\u0026gt;\u0026thinsp;484.26 and low catechin quality index (LCQI) with CQI\u0026thinsp;\u0026lt;\u0026thinsp;484.26 (Kilel et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2013\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCQI = (EGCG\u0026thinsp;+\u0026thinsp;ECG) / EGC*100), where EGCG, ECG, and EGC represent epigallocatechin gallate, epicatechin gallate, and epigallocatechin, respectively.\u003c/p\u003e \u003cp\u003eInitially, variance analysis was employed to assess the disparities in mycorrhizal colonization rates of \u003cem\u003eCamellia sinensis\u003c/em\u003e between the two CQI levels. A similarity analysis using the Adonis test from the \"vegan\" package was conducted to determine if there were significant differences in the AM fungi community structure between LCQI and HCQI. Principal coordinate analysis (PCoA) of the two AM fungi communities was visualized using the \"PCoA\" function from the \"ggplot2\" package in R.\u003c/p\u003e \u003cp\u003eIn the STAMP software, the raw sequencing ASV data from all cultivars was compared between the HCQI and LCQI groups to identify AM fungal genera that showed significant differences at the genus level. The \"betapart\" package was utilized to analyze sequencing data, investigating the causes of differences in the community structure of AM fungi in the rhizosphere soil and within the roots. The filtered ASVs from the AM fungi sequencing data encompassed both the rhizosphere soil and root samples of \u003cem\u003eCamellia sinensis\u003c/em\u003e, excluding any with average relative abundances under 0.01% or those detected in less than 20% of the samples from the analysis. Using 'Gephi (v 0.10)', co-occurrence networks at the genus level of different CQI levels of \u003cem\u003eCamellia sinensis\u003c/em\u003e rhizosphere soil and root-associated AM fungi were depicted. In microbial networks, positive cohesion refers to the mutually enhancing relationships between microbes, which may manifest as resource sharing, exchange of metabolic byproducts, or enhanced environmental adaptability. Negative cohesion reflects competitive or inhibitory relationships among microbial populations (Herren and McMahon, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). The stability of the rhizosphere soil and root-associated AM fungi networks was calculated by the ratio of the absolute values of positive to negative cohesion. In the R software suite, the \"edgeR\" package was utilized to filter specific ASVs. Subsequently, employing the LCQI as the control cohort, the selected ASVs were graphically represented on a volcano plot. This analytical approach was conducted to identify the significantly differential ASVs between the two CQI levels within the rhizosphere soil and root tissues of Camellia sinensis. A random forest analysis incorporating Amplicon Sequence Variants (ASVs) from AM fungi sequencing with the CQI was conducted to identify ASVs significantly associated with CQI.\u003c/p\u003e \u003cp\u003eThe Spearman correlation coefficient was used to conduct a correlation study assessing the associations among catechin quality, mycorrhizal colonization rates, the top four genera from AM fungal sequencing, and network stability, thereby pinpointing the key AM fungal characteristics significantly correlated with CQI. In R software, the \"piecewise SEM\" package was applied for visualizing and analyzing the structural equation model of composite variables, examining the intricate relationships among tea cultivars, available phosphorus in rhizosphere soil, mycorrhizal colonization rates, and the community characteristics of AM fungi in both rhizosphere soil and root tissues with catechin composition and the CQI. The optimal SEM model was determined using Fisher's C test, p-values, degrees of freedom (df), and Akaike Information Criteria (AIC).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eCatechin composition variability and hierarchical clustering results\u003c/p\u003e \u003cp\u003eSignificant variations in catechin composition were observed among different tea cultivars (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA to H). Specifically, the content of epicatechin gallate (ECG) in the TYDY was markedly higher than in the other cultivars, while the MF exhibited the lowest ECG content, with no significant differences in ECG content observed among the remaining cultivars (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). The ZYQ exhibited a markedly higher level of epigallocatechin (EGC) relative to the other cultivars, with no significant differences in EGC content among the other cultivars (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eD). The TYDY also had a significantly higher content of epigallocatechin gallate (EGCG) than the other cultivars (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eE). The catechin quality index (CQI) is a crucial indicator for evaluating tea quality. Utilizing the results from the hierarchical clustering analysis, the six tested tea cultivars could be categorized into two groups: one group with a high catechin quality index (HCQI) above 484.26, which included MF, ZYQ, and TYDY, and another group with a low catechin quality index (LCQI) below 484.26, which included XFC, JBH, and HJC (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eH).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAvailable phosphorus content in rhizosphere soil and AM fungal colonization rate\u003c/p\u003e \u003cp\u003eThe present study indicates that there were substantial variations in the total colonization rate of AM fungi and the phosphorus availability within the rhizosphere soil among \u003cem\u003eCamellia sinensis\u003c/em\u003e cultivars with different CQI levels. Specifically, the phosphorus availability within the rhizosphere soil of \u003cem\u003eCamellia sinensis\u003c/em\u003e in the LCQI group markedly exceeded that of the HCQI group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA), while the total colonization rate in the HCQI group was considerably more pronounced compared to the LCQI group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB). Concurrently, the rates of both arbuscular and hyphal colonization were significantly higher in the HCQI group compared to those in the LCQI group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC, \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eD).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAM Fungal alpha diversity, community composition, and beta diversity\u003c/p\u003e \u003cp\u003eThe Shannon diversity index did not exhibit significant variations between the HCQI group and the LCQI group for both rhizosphere soil and the root samples (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA, B). However, the composition of AM fungal communities in the rhizosphere soil of HCQI and LCQI showed significant differences (Adonis: R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.089, Pr\u0026thinsp;=\u0026thinsp;0.030, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eC). Similarly, the composition of AM fungal communities within the roots of HCQI and LCQI also exhibited significant differences (Adonis: R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.112, Pr\u0026thinsp;=\u0026thinsp;0.045, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eD). The sequencing data obtained from the rhizosphere soil and roots of \u003cem\u003eCamellia sinensis\u003c/em\u003e yielded ASVs belonging to nine distinct genera, with \u003cem\u003eParaglomus\u003c/em\u003e and \u003cem\u003eGlomus\u003c/em\u003e being the predominant genera (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eE). The relative abundance of \u003cem\u003eParaglomus\u003c/em\u003e notably rose in HCQI relative to LCQI (p\u0026thinsp;=\u0026thinsp;0.037), while \u003cem\u003eGlomus\u003c/em\u003e was significantly decreased (p\u0026thinsp;=\u0026thinsp;0.013, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eG, H).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eCharacteristics of the AM fungi co-occurrence network\u003c/p\u003e \u003cp\u003eMicrobial co-occurrence networks are instrumental in elucidating interspecies relationships and the mechanisms of coexistence and interaction among different microbes within an ecosystem. Within the rhizosphere soil of \u003cem\u003eCamellia sinensis\u003c/em\u003e, the co-occurrence network constructed from AM fungi exhibited a higher number of nodes for HCQI compared to LCQI, although the number of edges was less (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA, B). Within the roots of \u003cem\u003eCamellia sinensis\u003c/em\u003e, the AM fungal co-occurrence network revealed a predominance of the \u003cem\u003eParaglomus\u003c/em\u003e genus in modules associated with HCQI, whereas the \u003cem\u003eGlomus\u003c/em\u003e genus was more prevalent in those associated with LCQI (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eC, D). The co-occurrence network\u0026rsquo;s stability, as inferred from the positive and negative cohesion within the microbial network, indicated that the network constructed by AM fungi in the rhizosphere soil for HCQI was significantly more stable than that for LCQI (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eE).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eScreening for ASVs with significant impact on CQI\u003c/p\u003e \u003cp\u003eBased on the edgeR differential analysis, ASVs were selected for volcano plot visualization in both the rhizosphere soil and within the rhiza of \u003cem\u003eCamellia sinensis\u003c/em\u003e. The ASVs with significantly upregulated and downregulated expression in HCQI compared to LCQI were predominantly from the genera \u003cem\u003eParaglomus\u003c/em\u003e and \u003cem\u003eGlomus\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eA, B). In the \u003cem\u003eCamellia sinensis\u0026rsquo;\u003c/em\u003e rhizosphere soil, there was a higher number of significantly upregulated ASVs of \u003cem\u003eParaglomus\u003c/em\u003e in HCQI compared to \u003cem\u003eGlomus\u003c/em\u003e, while the number of significantly downregulated ASVs of \u003cem\u003eGlomus\u003c/em\u003e exceeded that of \u003cem\u003eParaglomus\u003c/em\u003e when compared to LCQI (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eC). Consistent results were observed within the rhiza of \u003cem\u003eCamellia sinensis\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eD). Random forest analysis conducted with ASV data from both rhizosphere soil and rhiza against CQI indicated that these differentially expressed ASVs were still predominantly from the genera \u003cem\u003eParaglomus\u003c/em\u003e and \u003cem\u003eGlomus\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eE, F).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eSpearman correlation and piecewise structural equation model analysis\u003c/p\u003e \u003cp\u003eTo more effectively reveal the relationship between the green tea CQI and AM fungal colonization rate as well as community structure, we performed a correlation analysis of catechin components, CQI, available phosphorus content, and mycorrhizal colonization rate with the characteristics of AM fungal communities in rhizosphere soil and rhiza of \u003cem\u003eCamellia sinensis\u003c/em\u003e. Additionally, a piecewise structural equation model (piecewise SEM) was utilized to elucidate the pathways by which AM fungi influence the CQI of green tea. Spearman's correlation analysis revealed that the content of EGCG and EGC, as well as the green tea CQI, were strongly positively correlated with total AMF colonization and arbuscular colonization (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA, B). The content of EGCG and the green tea CQI were both significantly negatively correlated with the rhizosphere soil\u0026rsquo;s available phosphorus content (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA, B). The correlation results with the AM fungal community traits within the rhizosphere soil indicated that the EGCG content was notably positively correlated with the diversity and network stability of the AM fungi in the rhizosphere soil; the EGC content was markedly positively correlated with network stability; and the CQI was notably negatively correlated only with the relative abundance of \u003cem\u003eGlomus\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA). The \u003cem\u003eCamellia sinensis\u0026rsquo;\u003c/em\u003e rhiza correlation results showed that both the EGCG content and the CQI were significantly positively correlated with the \u003cem\u003eParaglomus\u003c/em\u003e and notably oppositely correlated with the relative abundance of \u003cem\u003eGlomus\u003c/em\u003e, and the ECG content was positively correlated with network stability (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eB). By constructing a piecewise SEM, we discovered that the influence of tea cultivar and rhizosphere soil available phosphorus on green tea CQI is primarily mediated through two distinct pathways (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eC, D). One pathway is that the tea cultivars and the available phosphorus content in rhizosphere soil noticeably affect the colonization rate, which in turn influences the content of the EGCG, ECG, and EGC and subsequently significantly impacts the CQI (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eC, D). The second pathway is that the tea cultivar and the rhizosphere soil available phosphorus significantly influence Rhiza AM fungal community characteristics, which then affect the CQI (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eD).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn the current study, nine AM fungal genera were identified within the rhizosphere soil and roots of six distinct tea cultivars. \u003cem\u003eParaglomus\u003c/em\u003e and \u003cem\u003eGlomus\u003c/em\u003e were found to have the highest relative abundance across all cultivars, underscoring their prevalent role in tea gardens. It is noteworthy that the combined relative abundance of \u003cem\u003eParaglomus\u003c/em\u003e and \u003cem\u003eGlomus\u003c/em\u003e within the roots of \u003cem\u003eCamellia sinensis\u003c/em\u003e was further elevated compared to that in the rhizosphere soil. The previous study found that, under various agricultural management systems, tillage practices significantly impact the AM fungal populations under investigation (Douds Jr et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1995\u003c/span\u003e). The tea gardens in the present study are characteristic of organic management practices, with substantial organic fertilizers applied annually at year-end, which likely contributes to the abundance of \u003cem\u003eParaglomerales\u003c/em\u003e. \u003cem\u003eParaglomerales\u003c/em\u003e are more commonly found in organically managed soils, contrasting with conventional methods (Gosling et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe tea cultivar and the rhizosphere soil\u0026rsquo;s available phosphorus content notably affect the mycorrhizal colonization rate and community structure of AM fungi in the roots of \u003cem\u003eCamellia sinensis\u003c/em\u003e. The phenomenon that the soil phosphorus content is negatively correlated with the density of AM fungal spores is commonly observed (Carrenho, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1998\u003c/span\u003e; Santos and Carrenho, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). The lowest available soil phosphorus content (12.60 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) had the highest mycorrhizal colonization rate of 100%, while the tea garden with the highest available soil phosphorus content (28.17 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) had the lowest rate of mycorrhizal colonization (Sharma et al., \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). This implies that in the phosphorus-rich soils, plants may reduce their dependence on mycorrhizal associations. In this study, the HCQI group\u0026rsquo;s mycorrhizal colonization rate was significantly higher than the LCQI. The available phosphorus content in the HCQI group ranged from 5.23 to 14.14 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e; while for those with LCQI, it varied between 18.64 and 68.89 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, showing a significant difference. These results are supportive of previous research. e.g., Santos and Carrenho (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2011\u003c/span\u003e) and Qin et al. (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the present study, the relative abundance of \u003cem\u003eGlomus\u003c/em\u003e in the rhizosphere soil of \u003cem\u003eCamellia sinensis\u003c/em\u003e at the HCQI group was not significantly different from that at the LCQI group. However, within the roots of \u003cem\u003eCamellia sinensis\u003c/em\u003e at the LCQI group, which had a higher available phosphorus level, the relative abundance of \u003cem\u003eGlomus\u003c/em\u003e was significantly higher than at the HCQI group (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eE). Additionally, the relative abundance of \u003cem\u003eGlomus\u003c/em\u003e within the roots showed a significantly positive correlation with the available phosphorus (AP) content, further indicating the competitive strength of \u003cem\u003eGlomus\u003c/em\u003e under conditions of high soil AP. \u003cem\u003eCamellia sinensis\u003c/em\u003e with a high CQI level, which corresponded to lower available phosphorus levels in the rhizosphere, showed a higher relative abundance of \u003cem\u003eParaglomus\u003c/em\u003e within the roots than in those with a low CQI. Furthermore, the CQI showed a markedly negative correlation with the AP content (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA, B). This also indicated that the significant differences in soil-available phosphorus (AP) content led to differences in the AM fungal community structure within the root of \u003cem\u003eCamellia sinensis\u003c/em\u003e among varying CQI levels. Feng et al. sequenced AM fungi in subtropical citrus orchards in southern China and found a significant positive correlation between the relative abundance of \u003cem\u003eGlomus\u003c/em\u003e and the available phosphorus (AP) and the ratio of AP to total phosphorus (TP), indicating its strong tolerance and competitiveness in agricultural soils with higher AP content (Feng et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). In savanna ecosystems, the rhizosphere soil\u0026rsquo;s relative abundance of \u003cem\u003eParaglomus\u003c/em\u003e was markedly negatively correlated with the content of available soil phosphorus (Tour\u0026eacute; et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Although much research has linked the occurrence of \u003cem\u003eParaglomus\u003c/em\u003e to soil conditions, particularly soil phosphorus, their results are contradictory (Gosling et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the present study, \u003cem\u003eCamellia sinensis\u003c/em\u003e with a higher level of CQI recruited more \u003cem\u003eParaglomus\u003c/em\u003e within their roots, while the lower level of CQI enriched more \u003cem\u003eGlomus\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eE). Crop type and soil physicochemical properties exert significant influence on mycorrhizal colonization rates and the dominant AM fungal genus, which may account for the diversity observed in AM fungal communities (Koskey et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Zhang et al., \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). The mycorrhizal colonization rate influenced the catechin composition, thereby affecting the CQI. The mycorrhizal colonization rate itself did not directly influence the CQI of green tea, but it may alter the quality of the tea through a series of indirect effects. The mutualistic association established between AM fungi and vegetation bestows multiple benefits upon the host plant, including the enhancement of photosynthesis, which can improve photosynthetic efficiency, increase biomass, and increase productivity (Baas and Kuiper, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1989\u003c/span\u003e; Black et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). Furthermore, the synthesis of catechins is to some extent reliant on the carbon source provided by \u003cem\u003eCamellia sinensis\u003c/em\u003e through the photosynthetic fixation of atmospheric carbon dioxide (Xiang et al., \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). The catechin compounds in green tea primarily consist of eight monomers: catechin (DL-C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (CG), epicatechin gallate (ECG), gallocatechin gallate (GCG), and epigallocatechin gallate (EGCG). Among these, EGCG ranges as the predominant, accounting for approximately 50\u0026ndash;60% of the total catechin content. The CQI is determined from the content of EGCG, ECG, and EGC (Kilel et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2013\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe present study showed that the cultivar of \u003cem\u003eCamellia sinensis\u003c/em\u003e and the rhizosphere soil\u0026rsquo;s available phosphorus content have a big impact on the mycorrhizal colonization rate of \u003cem\u003eCamellia sinensis\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eC, D). There is also a strong positive relationship between the CQI and the total colonization rate (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA). This discovery suggested that the differences in \u003cem\u003eCamellia sinensis\u003c/em\u003e cultivars and the rhizosphere soil\u0026rsquo;s available phosphorus content led to variations in mycorrhizal colonization rates, which may further influence the photosynthesis of \u003cem\u003eCamellia sinensis\u003c/em\u003e. The changes in photosynthesis may, in turn, affect the composition of catechin compounds, ultimately impacting the CQI of green tea. Therefore, although the mycorrhizal colonization rate itself does not directly determine the CQI, it indirectly affects the quality of green tea by modulating photosynthesis and catechin synthesis. Mycorrhizal colonization can also modulate the concentrations of indigenous plant hormones, such as abscisic acid and jasmonic acid, which are integral to secondary plant metabolism (Adolfsson et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Mandal et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). In addition to nutritional effects, mycorrhizal systems can also shape plant secondary metabolism through mechanisms unrelated to nutrient exchange, including modulating the plant's responsiveness to environmental challenges (Schweiger et al., \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Schweiger and M\u0026uuml;ller, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2015\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn our study, the variations in the relative abundance of \u003cem\u003eParaglomus\u003c/em\u003e and \u003cem\u003eGlomus\u003c/em\u003e contributing to the variation in green tea CQI may be attributed to their distinct carbon (C) requirements. \u003cem\u003eParaglomus\u003c/em\u003e typically forms smaller spores and has a lower carbon demand compared to \u003cem\u003eGlomus\u003c/em\u003e species (Morton and Redecker, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Qiu et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). This may imply that \u003cem\u003eParaglomus\u003c/em\u003e has a lower carbon demand from the plant or that it can more efficiently utilize the carbon resources provided by the host plant, whereas \u003cem\u003eGlomus\u003c/em\u003e may be less efficient in utilizing the carbon allocated to it by the host plant's photosynthesis. The biosynthesis of catechins, which is contingent upon the carbon derived from the photosynthetic activity of \u003cem\u003eCamellia sinensis\u003c/em\u003e, may be adversely affected if the plant cannot efficiently modulate its carbon distribution to satisfy the metabolic requirements of its associated \u003cem\u003eGlomus\u003c/em\u003e. This could result in a scarcity of carbon resources, thereby impacting the production and accumulation of catechins. The spore morphology of \u003cem\u003eParaglomus\u003c/em\u003e is difficult to distinguish from that of \u003cem\u003eGlomus\u003c/em\u003e; however, there are significant differences in their phylogenetic positions at the molecular level and in their fatty acid compositions. This also suggests that they may have unique ecological adaptations and evolutionary histories (Morton and Redecker, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). \u003cem\u003eParaglomus\u003c/em\u003e typically possesses a more widespread extraradical mycelial system compared to \u003cem\u003eGlomus\u003c/em\u003e (Treseder et al., \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Qiu et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). The increase of certain species of \u003cem\u003eParalomus\u003c/em\u003e within the plant may facilitate the acquisition of nutrients with poor mobility, such as phosphorus (P), by the plant (Dai et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Gosling et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Under conventional agricultural management systems, a high abundance of \u003cem\u003eParaglomus\u003c/em\u003e may have a positive impact on wheat production, whereas some species of the \u003cem\u003eGlomus\u003c/em\u003e genus may have an adverse effect on wheat growth in organic agricultural frameworks (Dai et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). \u003cem\u003eParaglomerales\u003c/em\u003e, as AM fungi, serve as a principal mediator in the carbon cycle, transferring plant photosynthetic products to the soil microbial network, thereby promoting the distribution and cycling of carbon within the rhizosphere ecosystem (H\u0026uuml;nninghaus et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The growth suppression in plants by AM fungi could result from the host plant's inability to adjust its rate of carbon assimilation to compensate for the increased cost related to the carbon demands of the AM fungi (Koide and Elliott, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e1989\u003c/span\u003e).\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eAlthough numerous studies have reported the benefits of AM fungi within agroecosystems, our understanding remains limited regarding the impact of AM fungi on CQI of the \u003cem\u003eCamellia sinensis\u003c/em\u003e, particularly in green tea. In our study, \u003cem\u003eParaglomu\u003c/em\u003es and \u003cem\u003eGlomus\u003c/em\u003e were identified as the dominant AM fungal genera in the rhizosphere soil and the roots of \u003cem\u003eCamellia sinensis\u003c/em\u003e in a red soil tea garden experimental site. The cultivar of \u003cem\u003eCamellia sinensis\u003c/em\u003e and the rhizosphere soil\u0026rsquo;s available phosphorus level noticeably affected both the mycorrhizal colonization rate within the tea roots and the AM fungal community composition. The mycorrhizal colonization rate, in turn, influences the catechin composition in tea leaves, thereby affecting the green tea catechin quality index. Additionally, the differences in the AM fungal community composition significantly impacted the green tea catechin quality index. The concentration of available phosphorus in the rhizosphere soil is a primary influence in altering the mycorrhizal colonization rate within tea roots. \u003cem\u003eParaglomus\u003c/em\u003e may exhibit lower carbon requirements or more efficient utilization of the host \u003cem\u003eCamellia sinensis\u003c/em\u003e' s carbon resources compared to \u003cem\u003eGlomus\u003c/em\u003e, further influencing the catechin quality index of the tea leaves. These results enhance our comprehension of the potential of \u003cem\u003eParaglomus\u003c/em\u003e in enhancing the catechin quality index of green tea. Future research could focus on inoculating \u003cem\u003eCamellia sinensis\u003c/em\u003e with \u003cem\u003eParaglomus\u003c/em\u003e species of AM fungi to modulate the catechin composition in green tea, thereby improving its quality and offering a novel approach for cultivating premium green tea.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eThe authors thank supports by the Joint Fund for Regional (2024JJ7230), and the Hunan Provincial Science and Technology Innovation Major Program (2021NK1020).\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u0026nbsp;\u003c/strong\u003eAll authors contributed to the study conception and design. Pei Yuan: \u0026nbsp;Writing - original draft, Data curation. YingZi Wang: Funding acquisition, Project administration. JianWei Peng: Methodology, Resources. Ya Chen: Investigation. JingJin Li: Investigation. Mamdouh A. Eissa: Writing \u0026ndash; review and editing. GongWen Luo: Methodology, Software and Visualization. Chang Tian: Conceptualization, Methodology, Resources and Supervision.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of Competing Interest\u0026nbsp;\u003c/strong\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.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u0026nbsp;\u003c/strong\u003eData will be made available on request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAdolfsson, L., Nziengui, H., Abreu, I. N., \u0026Scaron;imura, J., Beebo, A., Herdean, A., Moritz, T., Nov\u0026aacute;k, O., Ljung, K., Schoefs, B., Spetea, C (2017) Enhanced secondary-and hormone metabolism in leaves of arbuscular mycorrhizal Medicago truncatula. Plant Physiology, 175(1), 392-411.\u003c/li\u003e\n \u003cli\u003eAhammed, G. J., Li, X (2022) Hormonal regulation of health-promoting compounds in tea (Camellia sinensis L.). Plant Physiology and Biochemistry, 185, 390-400.\u003c/li\u003e\n \u003cli\u003eBaas, R., Kuiper, D (1989) Effects of vesicular‐arbuscular mycorrhizal colonization and phosphate on Plantago major ssp. pleiosperma in relation to internal cytokinin concentrations. Physiologia plantarum, 76(2), 211-215.\u003c/li\u003e\n \u003cli\u003eBlack, K. G., Mitchell, D. T., Osborne, B. A (2000) Effect of mycorrhizal‐enhanced leaf phosphate status on carbon partitioning, translocation and photosynthesis in cucumber. Plant, Cell \u0026amp; Environment, 23(8), 797-809.\u003c/li\u003e\n \u003cli\u003eBolyen, E., Rideout, J. R., Dillon, M. R., et al., (2019) Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nature biotechnology, 37(8), 852-857.\u003c/li\u003e\n \u003cli\u003eCarrenho, R (1998) Influ\u0026ecirc;ncia de diferentes esp\u0026eacute;cies de plantas hospedeiras e fatores ed\u0026aacute;ficos no desenvolvimento de fungos micorr\u0026iacute;zicos arbusculares (FMA). Rio Claro, Tese de Doutorado. Universidade Estadual Paulista.\u003c/li\u003e\n \u003cli\u003eChen, W., Ye, T., Sun, Q., Niu, T., Zhang, J (2021) Arbuscular mycorrhizal fungus alters root system architecture in Camellia sinensis L. as revealed by RNA-Seq analysis. Frontiers in Plant Science, 12, 777357.\u003c/li\u003e\n \u003cli\u003eDai, M., Hamel, C., Bainard, L. D., Arnaud, M. S., Grant, C. A., Lupwayi, N. Z., Malhi, S. S., Lemke, R (2014) Negative and positive contributions of arbuscular mycorrhizal fungal taxa to wheat production and nutrient uptake efficiency in organic and conventional systems in the Canadian prairie. Soil Biology and Biochemistry, 74, 156-166.\u003c/li\u003e\n \u003cli\u003eDouds Jr, D. D., Galvez, L., Janke, R. R., Wagoner, P (1995) Effect of tillage and farming system upon populations and distribution of vesicular-arbuscular mycorrhizal fungi. Agriculture, ecosystems \u0026amp; environment, 52(2-3), 111-118.\u003c/li\u003e\n \u003cli\u003eDrew, L (2019) The growth of tea. Nature, 566(7742), S2-S2.\u003c/li\u003e\n \u003cli\u003eFeng, Z., Pan, C., Qin, Y., Xie, X., Liu, X., Chen, M., Zhang, W., Zhu, H., Yao, Q (2024) Natural grass coverage enriches arbuscular mycorrhizal fungal communities in subtropical citrus orchards through the regulation of Glomus on a regional scale. Applied Soil Ecology, 195, 105211.\u003c/li\u003e\n \u003cli\u003eGao, X., Liu, Y., Liu, C., Guo, C., Zhang, Y., Ma, C., Duan, X (2023). Individual and combined effects of arbuscular mycorrhizal fungi and phytohormones on the growth and physiobiochemical characteristics of tea cutting seedlings. Frontiers in Plant Science, 14, 1140267.\u003c/li\u003e\n \u003cli\u003eGosling, P., Proctor, M., Jones, J., Bending, G. D (2014) Distribution and diversity of Paraglomus spp. in tilled agricultural soils. Mycorrhiza, 24, 1-11.\u003c/li\u003e\n \u003cli\u003eHerren, C. M., McMahon, K. D (2017) Cohesion: a method for quantifying the connectivity of microbial communities. The ISME Journal, 11(11), 2426-2438.\u003c/li\u003e\n \u003cli\u003eHung, Y. T., Chen, P. C., Chen, R. L., Cheng, T. J (2010) Sequential determination of tannin and total amino acid contents in tea for taste assessment by a fluorescent flow-injection analytical system. Food Chemistry, 118(3), 876-881.\u003c/li\u003e\n \u003cli\u003eH\u0026uuml;nninghaus, M., Dibbern, D., Kramer, S., Koller, R., Pausch, J., Schloter-Hai, B., Urich, T., Kandeler, E., Bonkowski, M., Lueders, T (2019) Disentangling carbon flow across microbial kingdoms in the rhizosphere of maize. Soil Biology and Biochemistry, 134, 122-130.\u003c/li\u003e\n \u003cli\u003eJugran, A. K., Bahukhandi, A., Dhyani, P., Bhatt, I. D., Rawal, R. S., Nandi, S. K., Palni, L. M. S(2015) The effect of inoculation with mycorrhiza: AM on growth, phenolics, tannins, phenolic composition and antioxidant activity in Valeriana jatamansi Jones. Journal of soil science and plant nutrition, 15(4), 1036-1049.\u003c/li\u003e\n \u003cli\u003eKc, S., Long, L., Zhang, Q., Ni, K., Ma, L., Ruan, J (2022) Effect of interactions between phosphorus and light intensity on metabolite compositions in tea cultivar Longjing43. International Journal of Molecular Sciences, 23(23), 15194.\u003c/li\u003e\n \u003cli\u003eKilel, E. C., Faraj, A. K., Wanyoko, J. K., Wachira, F. N., Mwingirwa, V (2013) Green tea from purple leaf coloured tea clones in Kenya-their quality characteristics. Food Chemistry, 141(2), 769-775.\u003c/li\u003e\n \u003cli\u003eKoide, R., Elliott, G (1989) Cost, benefit and efficiency of the vesicular-arbuscular mycorrhizal symbiosis. Functional Ecology, 252-255.\u003c/li\u003e\n \u003cli\u003eKoske, R. E., Gemma, J. N (1989) A modified procedure for staining roots to detect VA mycorrhizas. Mycological Research, 92(4), 486-488.\u003c/li\u003e\n \u003cli\u003eKoskey, G., Avio, L., Turrini, A., Sbrana, C., B\u0026agrave;rberi, P (2023) Durum wheat-lentil relay intercropping enhances soil mycorrhizal activity but does not alter structure of arbuscular mycorrhizal fungal community within roots.\u0026nbsp;Agriculture, Ecosystems \u0026amp; Environment,\u0026nbsp;357, 108696.\u003c/li\u003e\n \u003cli\u003eLin, Z. H., Qi, Y. P., Chen, R. B., Zhang, F. Z., Chen, L. S (2012) Effects of phosphorus supply on the quality of green tea. Food Chemistry, 130(4), 908-914.\u003c/li\u003e\n \u003cli\u003eLiu, R. C., Xiao, Z. Y., Hashem, A., Abd_Allah, E. F., Xu, Y. J., Wu, Q. S (2021a) Unraveling the interaction between arbuscular mycorrhizal fungi and Camellia plants. Horticulturae, 7(9), 322.\u003c/li\u003e\n \u003cli\u003eLiu, R. C., Xiao, Z. Y., Hashem, A., Abd_Allah, E. F., Wu, Q. S (2021b) Mycorrhizal fungal diversity and its relationship with soil properties in Camellia oleifera. Agriculture, 11(6), 470.\u003c/li\u003e\n \u003cli\u003eMandal, S., Upadhyay, S., Wajid, S., Ram, M., Jain, D. C., Singh, V. P., Abdin, M. Z., Kapoor, R (2015) \u0026nbsp;Arbuscular mycorrhiza increase artemisinin accumulation in Artemisia annua by higher expression of key biosynthesis genes via enhanced jasmonic acid levels. Mycorrhiza, 25, 345-357.\u003c/li\u003e\n \u003cli\u003eMart\u0026iacute;nez‐Garc\u0026iacute;a, L. B., Richardson, S. J., Tylianakis, J. M., Peltzer, D. A., Dickie, I. A (2015) Host identity is a dominant driver of mycorrhizal fungal community composition during ecosystem development. New Phytologist, 205(4), 1565-1576.\u003c/li\u003e\n \u003cli\u003eMcGonigle, T. P., Miller, M. H., Evans, D. G., Fairchild, G. L., Swan, J. A (1990) A new method which gives an objective measure of colonization of roots by vesicular\u0026mdash;arbuscular mycorrhizal fungi. New phytologist, 115(3), 495-501.\u003c/li\u003e\n \u003cli\u003eMorton, J. B., Redecker, D (2001) Two new families of Glomales, Archaeosporaceae and Paraglomaceae, with two new genera Archaeospora and Paraglomus, based on concordant molecular and morphological characters. Mycologia, 93(1), 181-195.\u003c/li\u003e\n \u003cli\u003eNawara, S., Van Dael, T., Merckx, R., Amery, F., Elsen, A., Odeurs, W., Vandendriessche, H., Mcgrath, S.,Roisin, C., Jouany, Pellerin, S., Denoroy, P., Eichler-L\u0026ouml;bermann, B., B\u0026ouml;rjesson, G., Goos, P., Akkermans, W., Smolders, E (2017) A comparison of soil tests for available phosphorus in long‐term field experiments in Europe. European Journal of Soil Science, 68(6), 873-885.\u003c/li\u003e\n \u003cli\u003eNeuenkamp, L., Moora, M., \u0026Ouml;pik, M., Davison, J., Gerz, M., M\u0026auml;nnist\u0026ouml;, M., Jairus, T., Vasar, M., Zobel, M (2018) The role of plant mycorrhizal type and status in modulating the relationship between plant and arbuscular mycorrhizal fungal communities. New Phytologist, 220(4), 1236-1247.\u003c/li\u003e\n \u003cli\u003eQin, Z., Zhang, H., Feng, G., Christie, P., Zhang, J., Li, X., Gai, J (2020) Soil phosphorus availability modifies the relationship between AM fungal diversity and mycorrhizal benefits to maize in an agricultural soil. Soil Biology and Biochemistry, 144, 107790.\u003c/li\u003e\n \u003cli\u003eQiu, Y., Guo, L., Xu, X., Zhang, L., Zhang, K., Chen, M., Zhao, Y., Burkey, K. O., Shew, H. D., Zobel, R. W., Zhang, Y., Hu, S (2021) Warming and elevated ozone induce tradeoffs between fine roots and mycorrhizal fungi and stimulate organic carbon decomposition. Science advances, 7(28), eabe9256.\u003c/li\u003e\n \u003cli\u003eSantos, F. E. F. D., Carrenho, R (2011) Diversidade de fungos micorr\u0026iacute;zicos arbusculares em remanescente florestal impactado (Parque Cinq\u0026uuml;enten\u0026aacute;rio-Maring\u0026aacute;, Paran\u0026aacute;, Brasil). Acta Botanica Brasilica, 25, 508-516.\u003c/li\u003e\n \u003cli\u003eSchweiger, R., M\u0026uuml;ller, C (2015) Leaf metabolome in arbuscular mycorrhizal symbiosis. Current opinion in plant biology, 26, 120-126.\u003c/li\u003e\n \u003cli\u003eSchweiger, R., Baier, M. C., M\u0026uuml;ller, C (2014) Arbuscular mycorrhiza-induced shifts in foliar metabolism and photosynthesis mirror the developmental stage of the symbiosis and are only partly driven by improved phosphate uptake. Molecular Plant-Microbe Interactions, 27(12), 1403-1412.\u003c/li\u003e\n \u003cli\u003eSharma, C., Gupta, R. K., Pathak, R. K., Choudhary, K. K (2013) Seasonal colonization of arbuscular mycorrhiza fungi in the roots of Camellia sinensis (tea) in different tea gardens of India. International Scholarly Research Notices, 2013(1), 593087.\u003c/li\u003e\n \u003cli\u003eTour\u0026eacute;, G. P. T., Kon\u0026eacute;, A. W., Nandjui, J., Ebou, A. E., Otinga, A. N., Ma\u0026iuml;ga, A. A., Kouadjo, C. G. Z., Thio, S., Z\u0026eacute;z\u0026eacute;, A (2023) Changes in arbuscular mycorrhizal fungal communities, mycorrhizal soil infectivity, and phosphorus availability under Chromolaena odorata (Asteraceae) invasions in a West-African forest-savanna ecotone. Mycorrhiza, 33(4), 257-275.\u003c/li\u003e\n \u003cli\u003eTreseder, K. K., Allen, E. B., Egerton‐Warburton, L. M., Hart, M. M., Klironomos, J. N., Maherali, H., Tedersoo, L (2018) Arbuscular mycorrhizal fungi as mediators of ecosystem responses to nitrogen deposition: A trait‐based predictive framework. Journal of Ecology, 106(2), 480-489.\u003c/li\u003e\n \u003cli\u003eWan, C., Ouyang, J., Li, M., Rengasamy, K. R., Liu, Z (2024) Effects of green tea polyphenol extract and epigallocatechin-3-O-gallate on diabetes mellitus and diabetic complications: Recent advances. Critical reviews in food science and nutrition, 64(17), 5719-5747.\u003c/li\u003e\n \u003cli\u003eWang, N., Wang, Y., Zhang, X., Wu, Y., Zhang, L., Liu, G., Fu, J., Li, X., Mu, D., Li, Z (2024) Elevated Ozone Reduces the Quality of Tea Leaves but May Improve the Resistance of Tea Plants. Plants, 13(8), 1108.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eWang, S. Y., Wei, H., Chen, K. Y., Dong, Q., Ji, B. M., Zhang, J (2021) \u0026nbsp;Practical methods for arbuscular mycorhizal fungal spore densty, hyphal density and colonization rate of AMF. Bio-Protoc. J, 101, e2104253.\u003c/li\u003e\n \u003cli\u003eXiang, P., Zhu, Q., Tukhvatshin, M., Cheng, B., Tan, M., Liu, J., Wang, X., Huang, J., Gao, S., Lin, D., Zhang, Y., Wu, L., Lin, J., 2021. Light control of catechin accumulation is mediated by photosynthetic capacity in tea plant (Camellia sinensis). BMC Plant Biology, 21, 1-13.\u003c/li\u003e\n \u003cli\u003eXin, W., Zhang, J., Yu, Y., Tian, Y., Li, H., Chen, X., Li, W., Liu, Y., Lu, T., He, B., Xiong, Y., Yang, Z., Xu, T., Tang, W (2024) Root microbiota of tea plants regulate nitrogen homeostasis and theanine synthesis to influence tea quality. Current Biology, 34(4), 868-880.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eYang, Y., Ke, J. P., Yang, Z., Chen, C. H., Li, J. Y., Yu, J. Y., Zhang, Y. X., Bao, G. H (2024) Green tea hydroxycinnamoylated catechins extend lifespan and attenuate A\u0026beta;-induced paralysis of Caenorhabditis elegans via anti-oxidation and peptides dis-aggregation. Industrial Crops and Products, 212, 118390.\u003c/li\u003e\n \u003cli\u003eZhang, J. L., Song, J., Kang, Y. H., Wen, Y. Y., Nong, Y. J., Wang, Q., Qin, X. J., Chen,T. S., Li, Y. R (2024) The Community of Arbuscular Mycorrhizal Fungi in Sugarcane Rhizosphere Soils in Guangxi, China. Sugar Tech, 26(1), 131-142.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"mycorrhiza","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"mcor","sideBox":"Learn more about [Mycorrhiza](http://link.springer.com/journal/572)","snPcode":"572","submissionUrl":"https://submission.nature.com/new-submission/572/3","title":"Mycorrhiza","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Tea cultivar, Rhizosphere, Mycorrhizal colonization, Diversity, Catechin quality index","lastPublishedDoi":"10.21203/rs.3.rs-5424269/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5424269/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Soil microbes have an impact on the quality of green tea leaves in addition to soil conditions and Camellia sinensis cultivar. Arbuscular mycorrhizal (AM) fungi can significantly improve soil quality and crop productivity, however, the specific AM fungal groups that affect the catechin quality index (CQI) of green tea are not yet clear. In the present study, rhizosphere soil samples, root samples, and fresh tea leaves from six different Camellia sinensis cultivars in Hunan Province, China were collected. Utilizing high-throughput Illumina amplicon sequencing technology, the taxonomic diversity and community composition of AM fungi in the rhizosphere soil and roots were investigated, as well as the mycorrhizal colonization rate. It was discovered that the two main AM fungal genera in the Camellia sinensis roots and rhizosphere were Paraglomus and Glomus. A higher catechin quality index (HCQI) correlates with greater accumulation of Paraglomus in the roots of Camellia sinensis. Tea cultivar and rhizosphere soil’s available phosphorus content significantly affected the mycorrhizal colonization rate and the composition of the AM fungal community within the roots. The mycorrhizal colonization rate impacted the catechin composition, consequently influencing the catechin quality index of green tea. Furthermore, fluctuations in the proportional presence of Paraglomus and Glomus within the roots of Camellia sinensis notably affected the CQI. In summary, heightened mycorrhizal colonization and enhanced Paraglomus prevalence substantially elevate the CQI of green tea. This finding was of considerable importance for the application of AM fungi in the production of high-quality green tea.","manuscriptTitle":"Paraglomus and Glomus Arbuscular Mycorrhizal Fungi induce the Green Tea Catechin Quality Index and Phosphorus bioavailability in Tropical soils","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-11-28 15:48:33","doi":"10.21203/rs.3.rs-5424269/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-01-12T23:29:18+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-12-19T19:59:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"69161081214847295628560396467167599110","date":"2024-11-21T20:14:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"121949784636092800667782909528606333767","date":"2024-11-18T17:01:30+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-11-12T01:21:17+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-12T00:40:08+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-11-11T14:03:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"Mycorrhiza","date":"2024-11-10T04:39:46+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"mycorrhiza","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"mcor","sideBox":"Learn more about [Mycorrhiza](http://link.springer.com/journal/572)","snPcode":"572","submissionUrl":"https://submission.nature.com/new-submission/572/3","title":"Mycorrhiza","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"d1b1d196-a4af-45d7-8011-cfbb90b4546f","owner":[],"postedDate":"November 28th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-02-24T15:59:43+00:00","versionOfRecord":{"articleIdentity":"rs-5424269","link":"https://doi.org/10.1007/s00572-025-01185-9","journal":{"identity":"mycorrhiza","isVorOnly":false,"title":"Mycorrhiza"},"publishedOn":"2025-02-20 15:57:05","publishedOnDateReadable":"February 20th, 2025"},"versionCreatedAt":"2024-11-28 15:48:33","video":"","vorDoi":"10.1007/s00572-025-01185-9","vorDoiUrl":"https://doi.org/10.1007/s00572-025-01185-9","workflowStages":[]},"version":"v1","identity":"rs-5424269","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5424269","identity":"rs-5424269","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}