Drought stress selectively increases the expression levels of scent-related genes and the emission rates of scent compounds in flowers of Styrian oil pumpkin

Drought stress selectively increases the expression levels of scent-related genes and the emission rates of scent compounds in flowers of Styrian oil pumpkin | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 15 July 2025 V1 Latest version Share on Drought stress selectively increases the expression levels of scent-related genes and the emission rates of scent compounds in flowers of Styrian oil pumpkin Authors : Monica Barman 0000-0003-1406-4809 [email protected] , Marion Christine Hoepflinger , Raimund Tenhaken , and Stefan Dötterl Authors Info & Affiliations https://doi.org/10.22541/au.175255568.86700619/v1 231 views 232 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Due to shifting climatic conditions, the occurrence of drought is rising worldwide. Yet, how this environmental stressor affects the expression levels of genes involved in the biosynthesis of floral scent compounds, that act as a major cue for attracting pollinators, remains unexplored. In this study, we investigated how drought stress impacts the emission rates of floral scent compounds in Styrian oil pumpkin ( Cucurbita pepo subsp. pepo var. styriaca Greb.), that relies on pollinators for setting fruit. Also, we evaluated the expression level of genes potentially involved in floral scent biosynthesis. We found that drought stress increased the amounts (per flower fresh weight) of seven floral volatiles, while the other twenty-five compounds had similar emission rates as the controls. By performing de novo transcriptome analyses, we were able to identify several candidate genes for compounds that were emitted in higher rates in flowers of drought-stressed plant, and qPCR analyses revealed that drought upregulated the expression of some of these genes. This is the first analysis showing that drought influences the expression of flower scent-related genes, and points at future studies to explore functional links between the increased expression rate of these genes and the emission rate of the related volatiles. Introduction: Due to changing climatic conditions, the intensities of droughts are increasing globally and more of such events are forecasted to occur in the future (IPCC 2024). Drought has a number of serious consequences for terrestrial ecosystems, and the processes affected include plant reproduction and pollination (Brown et al., 2016; Höfer et al., 2021). One reason these processes are affected is that drought affects several reproductive/flower traits that play an important role in attracting pollinators (Burkle and Runyon, 2016; Waser and price, 2016; Glenny et al., 2018; Barman et al., 2024; Brunet et al., 2025). Changes in such floral cues and signals, including the number of flowers, visual and olfactory cues of flowers, as well as nectar rewards, have the potential to influence the attractiveness of plants/flowers to insect pollinators, the flower visitation rates, and/or the duration of flower visits by pollinators (Burkle and Runyon, 2016, Glenny et al., 2018; Campbell et al., 2019; Descamps et al., 2021; Rering et al., 2020; Höfer et al., 2021; Dötterl and Gershenzon, 2023; Barman et al., 2024). Important visual cues of flowers are their colors, and floral scents are the olfactory cues of flowers (Kunze and Gumbert, 2001; Dötterl et al. 2014; Borghi et al., 2017). In contrary to floral colors that attract insect pollinators usually from smaller distances (Chittka and Raine, 2006), floral scents have a crucial role in both short-distance (Haverkamp et al. 2016, Heuel et al., 2025) and long-distance (Raguso et al., 2003; El-Sayed et al., 2018) signaling. Floral scents are lipophilic volatile molecules that are used by pollinators to discriminate amongst flowers of different species, or even amongst flowers with different rewards within a plant individual (Raguso, 2008; Dudareva et al., 2013; Jürgens et al., 2014). Based on their biosynthetic origin, floral scent compounds are categorized into different chemical classes, such as benzenoids and phenylpropanoids, terpenoids, and fatty acid derivatives (Pichersky and Gershenzon, 2002; Knudsen et al., 2006; Dötterl and Gershenzon, 2023). The biosynthesis and the emission of floral scent compounds is controlled by gene expression and enzyme activity (Dudareva et al., 2013), the transport of volatiles to outside the cells by transporters (Abebesin et al., 2017; Bergman et al., 2025), and the vaporization of the compounds into the surrounding air of flowers (Sagae et al., 2008). In the last decades, it has been shown that there are several biotic and abiotic factors such as pollution, herbivory, nutrient availability, and climate changes that can alter the floral scent emission, and thus, the communication with pollinators (Blande et al., 2014; Glenny et al., 2018; Ryalls et al., 2022; Cordeiro and Dötterl, 2023; Dötterl and Gershenzon, 2023). Indeed, several researchers have elucidated the impacts of climate change, specifically high temperature and drought, on the floral scent emission (Glenny et al., 2018; Campbell et al., 2019; Cordeiro and Dötterl, 2023). In the context of heat stress, it has mostly been found that the activity of enzymes and the accumulation of transcripts of certain upstream and downstream structural genes involved in the scent production in flowers are adversely affected, leading to a reduction in scent production and a smaller amount of scent released (Cna’ani et al., 2015; Barman and Mitra, 2021). Similarly, several recent investigations have shown that drought stress alters floral scent emission, both in terms of quantity and composition (Rering et al., 2020; Burkle and Runyon, 2016; Glenny et al., 2018, Campbell et al., 2019; Brunet et al., 2025). However, the effects of drought on the production of individual floral scent compounds and on the transcription levels of genes involved in their biosynthesis have never been explored together. Thus, there is a huge gap in understanding the molecular changes in floral scent biosynthesis caused by drought. In our previous study on the Styrian oil pumpkin (Barman et al., 2024), we observed that drought did not significantly affect the amount and overall composition of floral scent emitted by both male and female flowers, although drought stress did halve flower size and weight. This suggested that the production of scent per unit flower weight is increased during drought stress in this plant species. To test this hypothesis, here we investigated how drought affects the biosynthesis and production of flower scent compounds relative to flower weight. Specifically, we used previously collected flower scent data (Barman et al., 2024) and analysed the emission of specific volatile compounds per unit flower weight from both control and drought-stressed flowers. Furthermore, to better understand the underlying molecular processes of scent production, we assessed and compared the expression patterns of floral scent related genes in control and drought-stressed plants using real-time quantitative PCR (qPCR) guided by transcriptomic data. Materials and Methods 2.1 Plant material, growth conditions, sampling and analysis of floral scent This study uses floral scent data collected previously (Barman et al., 2024) by dynamic headspace from male flowers of Styrian oil pumpkin plants ( Cucurbita pepo subsp. pepo var. styriaca Greb.) grown under control (n = 9) and drought stress (n = 10) conditions, and analysed previously (Barman et al., 2024) by gas chromatography coupled to mass spectrometry (GC/MS). Female flowers have not been considered due to their very limited availability under drought stress (see Barman et al., 2024). Control plants were watered daily and drought plants every third day; in both conditions watering was done until water drained out of the bottom holes of each pot (for more details on growth conditions see Barman et al., 2024). In our previous analysis (Barman et al., 2024), floral scent amounts were analysed per flower, whereas in this study, we analysed the volatile amounts emitted per gram fresh weight of a flower. The weight of the flowers has been determined immediately after scent collections. 2.2 Identification of gene sequences To identify genes potentially involved in the biosynthesis of floral volatiles in pumpkin, we assembled de novo transcriptomic datasets of flowers ( n = 5, from five different plant individuals) and young leaves ( n = 3, from three of the five plant individuals used for flower samples) from control plants. Total RNA was isolated from petals and leaves using the method described in section 2.3. The samples were sent to Novogene (Cambridge, UK) for sequencing. De novo transcriptome assembly was performed using datasets from 30 million paired-end reads (2 × 150 bp) with Trinity (GitHub version 2.11.0) under default settings. The assembled transcripts were annotated using Diamond (GitHub version 2.11.0). Genes putatively involved in the biosynthesis of floral volatiles in pumpkin (e.g., linalool, phenylacetonitrile, 2-phenylethanol; Fig. 2B) were those that were up-regulated in flowers compared to leaves (as observed from the fragments per kilobase of transcript per million reads (FPKM); Table S2) and were known to be involved in the biosynthesis of such compounds in other plant species. 2.3 Preparation of RNA, cDNA and gene expression analyses of candidate genes Petals of fully bloomed flower ( n = 3-5, from different individuals each) from both control and drought-stressed plants were collected at 7:00 a.m., immediately snap-frozen in liquid nitrogen, and stored at -80 °C until further analysis. Total RNA was extracted from 100 mg of a sample using TRI-Reagent following the supplier’s protocol (Sigma Aldrich; see also Hoepflinger et al. 2024). Remaining genomic DNA was eliminated by RNase-free DNase treatment (EN0521, Thermo Fischer Scientific, Waltham, MA, USA). First-strand cDNA was synthesized from 2 μg total RNA using M-MuLV Reverse Transcriptase (RevertAid EP0441, Thermo Fischer Scientific) with an anchored oligo(d)T primer-mix, as per the manufacturer’s instructions. The resulting cDNA was utilized for expression analysis of the candidate genes (see below) through real-time quantitative PCR (qPCR) from our designed primer sets (Table S4) on an AriaMx cycler (Agilent Technologies, California, US) using 2x qPCRBIO SyGreen Mix Lo-ROX (PCRBIOSYSTEMS, London, UK) according to manufacturer’s instructions. Gene expression levels were determined by calculating ΔCt values relative to C. pepo Actin (housekeeping gene) according to Pfaffl et al. (2002). We found that the emission rate of some flower scent compounds per gram fresh weight is higher in drought compared to control flowers (see Results). To test if the increase in the emission of these compounds is controlled at the biosynthetic level, we evaluated the expression levels of genes potentially involved in their formation. Based on known biosynthetic pathways and scent genes (Dhandapani et al., 2019; Barman et al., 2023; Dötterl & Gershenzon, 2023), and comparisons of our flower and leaf transcriptomes (see 2.3), we were able to identify several genes potentially involved in the formation of floral volatiles in pumpkin. Genes potentially involved in the biosynthesis of the benzenoid/phenylpropanoid volatiles that had a higher emission rate in drought flowers (Fig. 2B) and studied here were: the transcription factor CpMYB , phenylalanine ammonia-lyase ( CpPAL ), phenylacetaldehyde reductase ( CpPAR ), cinnamoyl-CoA reductase ( CpCCR ), cinnamyl alcohol dehydrogenase ( CpCAD ), cinnamic acid 4-hydoxylase ( CpC4H ), aromatic amino acid decarboxylase ( CpAADC ), aromatic amino acid aminotransferase ( CpAAAT ). Genes potentially responsible for higher emission rates of phenylacetonitrile were the cytochrome P450 enzymes CpCYP79, CpCYP71 , and CpCYP77 . CpTPS was studied as candidate terpene synthase gene forming linalool, which was also increased under drought stress, in pumpkin flowers. As a negative control, we monitored the expression levels of benzoyl-coenzyme A (CoA): benzyl alcohol benzoyl transferase ( CpBEBT ), that is responsible for the production of benzyl benzoate, a volatile found to be equally emitted from both control and drought-stressed pumpkin flowers (Table S1). 2.4 Statistical analysis All statistical tests were performed using R programming language (v.4.2.2; R Core Team, 2021) in the RSTUDIO platform (RSTUDIO 2021.09.2 + 382 ‘Ghost Orchid’ Release). The variations in the floral volatile and gene expression patterns in control and drought plants were represented via boxplots using ‘GGPLOT2’ package (v.3.4.0). In these graphs, the thick black horizontal lines show the median, the boxes represent the interquartile range, the whiskers display the range from the minimum to the maximum excluding outliers, and black dots highlight the outliers. To assess the influence of drought stress on floral volatiles (absolute amounts of single compounds per flower fresh weight) and gene expression patterns, the non-parametric Wilcoxon rank-sum test was applied. Significance levels are presented as: p > 0.05 is nonsignificant (ns); *, p < 0.05; **, p < 0.01. Results: 3.1 Effects of drought on individual volatile compounds in pumpkin flowers From the 32 scent compounds overall detected from male flowers, not a single compound was negatively affected by drought. The amounts (per flower fresh weight) of seven compounds, however, were 3 to 9-times higher under drought stress: the phenylpropanoids/benzenoids: benzyl alcohol, ( E )-cinnamyl alcohol, 2-phenylethanol, p -vinylanisole and benzenepropanol, the nitrogen-bearing compound phenylacetonitrile, and the monoterpene linalool (Table S1; Fig. 1A-G). Fig. 1 Amounts per gram flower fresh weight of those volatile compounds (A-G) that were emitted in higher amounts from drought-stressed plants (n = 10) than from control plants (n = 9). Data were analyzed using non-parametric Wilcoxon rank-sum tests and the levels of significance are indicated as * for p < 0.05 and ** for p < 0.01. See also Table S1. 3.2 Candidate genes identified from transcriptome data From the assembled transcriptomics dataset (submitted to the NCBI Sequence Read Archive database under accession number PRJNA1285333) a total of 106,917 transcripts were identified. Thereof, we were able to screen between 7 and 537 transcripts that coded for genes potentially involved in the biosynthesis of floral scents in Styrian oil pumpkin (Table 1; Supplementary file S1). Out of all these transcripts, we considered those 1-2 transcripts that were most strongly upregulated in flowers as compared to leaves (Table S2; Table S3) for our qPCR studies. Table 1 Candidate scent-related genes screened from the Styrian oil pumpkin transcriptome dataset CpPAL Phenylalanine ammonia-lyase 57 CpCCR Cinnamoyl-CoA reductase 39 CpCAD Cinnamyl alcohol dehydrogenase 31 CpC4H Cinnamic acid 4-hydoxylase 10 CpMYB MYB transcription factor 537 CpCYP71 Cytochrome P450-71 protein 57 CpCYP77 Cytochrome P450-77 protein 7 CpCYP79 Cytochrome P450-79 protein 14 CpPAR Phenylacetaldehyde reductase 7 CpC4H Cinnamic acid 4-hydoxylase 10 CpAADC Aromatic amino acid decarboxylase 7 CpAAAT Aromatic amino acid aminotransferase 16 CpTPS Terpene synthase 22 CpBEBT Benzoyl-coenzyme A (CoA): benzyl alcohol benzoyl transferase 24 3.3 Impact of drought stress on the expression levels of scent-related genes Among the candidate genes (Table 1) that were potentially involved in the biosynthesis of those floral scents that were released in higher amounts per flower weight in drought stressed than control plants, the transcript levels of three compounds were increased, whereas the levels of the remaining compounds were unaffected by drought (Fig. 2A). Based on qPCR, the transcription level has been increased for CpPAL , the first key enzyme, that directs the carbon flow towards the phenylpropanoid/benzenoid pathway (Fig 2A(i), 2B). Similarly, drought stress resulted in increased expression levels of the cytochrome genes potentially involved in the biosynthesis of phenylacetonitrile, i.e., CpCYP79 and CpCYP71 (Fig. 2A (x, xi)). Fig. 2 (A) Expression levels of the candidate genes CpPAL (i), CpC4H (ii), CpCCR (iii), CpCAD (iv), CpMYB (v), CpBEBT (vi), CpPAR (vii), CpAADC (viii), CpAAAT (ix), CpCYP79 (x), CpCYP71 (xi), CpCYP77 (xii), CpTPS (xiii) involved in the biosynthesis of those floral volatiles in pumpkin that have higher emission rates per gram flower weight. Gene expression levels were calculated relative to CpActin (housekeeping gene), which was set to 1. (B) An overview of the biosynthesis of floral volatiles released from oil pumpkin and the genes potentially involved in their biosynthesis, according to transcriptomic data. Volatiles printed in blue are those that have higher emission rates per gram flower weight in drought stressed plants as compared to controls. Phenylpropanoids/ benzenoids given inside the grey dashed box are biosynthesized via the shikimate pathway. The given monoterpenes are biosynthesized via the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway inside the plastids (green box). Discussion: Our results show that drought stress increases the emission of seven scent compounds on a per flower weight basis in Styrian oil pumpkin, while other floral volatiles remain unaffected (Table S1). The emission rate of not a single compound was negatively affected, which is in agreement with our earlier finding that drought does not negatively impact the biosynthesis of volatile compounds (Barman et al., 2024). The expression levels of scent-related genes were either similar to those of control flowers or significantly elevated under drought stress. Overall, the observed higher emission rate of floral scent compounds due to drought stress can in some, but not all cases, be explained by higher expression levels of genes potentially involved in their biosynthesis. 4.1 Impacts of drought on pumpkin floral individual volatile compounds Although no difference was observed in the total amounts and overall composition of floral volatiles of Styrian oil pumpkin from drought-stressed and control plants on a flower basis in our previous study (Barman et al., 2024), our current investigation on individual compounds and a per flower weight basis revealed that the emission rate of the five phenylpropanoids/benzenoids (e.g. benzyl alcohol, ( E )-cinnamyl alcohol, 2-phenylethanol), the nitrogen-bearing compound phenylacetonitrile, and the monoterpene linalool were significantly higher (Table S1; Fig. 1). Several previous studies have shown that water-stressed plants emit a comparable amount of volatiles as compared to well-watered plants (Glenny et al., 2018), while other studies indicated an increase in the emission of total volatiles or specific compounds under the influence of drought stress, showing overall that effects of drought stress on floral scent are species-specific (Burkle and Runyon, 2016; Campbell et al., 2019; Rering et al., 2020; Höfer et al., 2022). These previous studies on drought stress have primarily examined volatile emissions on a per-flower basis, with no data available regarding emissions relative to flower weight. Such data, however, are available on vegetative tissues, with some previous studies having demonstrated that leaves respond to drought stress with increased secondary metabolite production, which is attributed to enhanced biosynthetic gene and enzyme activities (Rezayian et al., 2018; Yadav et al., 2021). Our findings on increased emissions of some of the floral scent compounds and no effect on others suggest that, despite reduced flower size under drought conditions, plants increase resource allocation or continue to allocate resources towards floral volatile production, likely to preserve pollinator interactions. Indeed, several of the compounds released by the oil pumpkin were previously shown to be perceived by or attract bee pollinators, among them generalist honey and bumblebees that also pollinate Styrian oil pumpkin flowers and specialist cucurbit pollinators (Salzmann et al., 2007; Zhang et al., 2022, Barman et al. 2023; Barman et al. unpublished), including volatiles (e.g., linalool) that were emitted in higher amounts per flower weight from drought-stressed flowers (Fig. 2). In addition to floral scents, we cannot dismiss the possibility that other cues, such as visual cues (floral color) or floral humidity (von Arx, 2013; Dotterl & Gershenzon, 2023) might be affected by drought stress and this could potentially affect the insect’s attraction as well. 4.2 Impacts of drought on the expression of scent-related genes Based on known scent biosynthetic pathways in cucurbits and other flowering species (Barman et al., 2023; Dötterl & Gershenzon, 2023), and on comparisons of our flower and leaf transcriptomes, we identified candidate genes (given in red in Fig. 2B) that are potentially involved in the formation of the volatile compounds emitted in higher amounts (per flower weight) from drought-stressed than control flowers (given in blue in Fig. 2B). Our observations of higher emissions of several phenylpropanoid/benzenoid compounds from flowers of drought-stressed plants is in agreement with the upregulation of the expression of genes involved in the shikimate biosynthetic pathway (Barman et al., 2023, Dötterl & Gershenzon, 2023), such as CpPAL (Fig. 2A(i)). PAL (Phenylalanine ammonia lyase) is known as the rate-limiting enzyme in the phenylpropanoid/benzenoid biosynthesis pathway and is the first key enzyme, that directs the carbon flow towards the formation of aromatic volatiles (Verdonk et al., 2003; Dudareva et al., 2004; Tohge et al., 2013). Further, plants that possess a floral scent profile rich in aromatic compounds have an increased expression of the PAL gene when compared to plants that mainly release scents of other biosynthetic routes (Cna’ani et al., 2015; Cheng et al., 2016; Barman and Mitra, 2021). In pumpkin, the higher expression of this gene in drought-stressed flowers likely helped to increase the channelization of substrates required for the biosynthesis of phenylpropanoids/benzenoids flower volatiles. This hypothesis partially explains the increased emissions of several benzenoid/phenylpropanoid volatiles in the flowers of drought-stressed plants (Fig. 2B); however, it does not explain why other benzenoids/phenylpropanpoids, such as benzyl benzoate and 1,4-dimethoxybenzene, remained unchanged compared to control flowers (Table. S1). Our finding of increased expression levels of CpCYP79 and CpCYP71 under drought stress conditions , (end product) genes (Fig. 2A (x, xi)) that are involved in forming phenylacetonitrile (PAN) (Dhandapani et al., 2019; Miki and Asano, 2014; Yamaguchi et al., 2016) helps to explain why the emission of this compound per flower weight was higher in drought-stressed than control plants. It has previously been demonstrated that PAN is possibly biosynthesized in two steps from phenylalanine, where this amino acid is first converted to ( E , Z) -phenylacetaldoxime (PAOx) by the cytochrome P450 (CYP) family 79 subfamily A protein, which is finally converted to PAN via the CYP family 71 protein in some plants (Miki and Asano, 2014; Dhandapani et al., 2019) and likely via CYP77As in other plants (Yamaguchi et al. 2023). Although we have identified, by our transcriptomics approach, potential genes from CYP family 71 ( CpCyp71 ), CYP family 79 subfamily A ( CpCyp79 ) as well as CYP family 77 subfamily A ( CpCyp77 ) (Table S1; Fig 2B), we only observed higher FPKM values in flowers as compared to leaves for CpCyp71 and CpCyp79 (Table S2) , suggesting that in Styrian oil pumpkin flowers CYP 71 and CYP 79 are involved in the biosynthesis of PAN. However, further detailed functional characterization of all these three genes is needed to determine their precise roles in the biosynthesis of PAN in pumpkin. Equal expression levels in flowers of both drought and control Styrian oil pumpkin plants were observed for the other studied genes viz. CpAADC, CpAAAT and CpPAR that are potentially involved in the biosynthesis of 2-phenylethanol, CpCCR and CpCAD potentially involved in ( E )-cinnamyl alcohol synthesis, CpC4H potentially involved in precursor formation of p -vinylanisole, CpTPS potentially involved in linalool biosynthesis and CpBEBT potentially involved in the formation of benzyl benzoate (Fig. 2A). All these pathway genes are characterized well in other flowering species such as petunia and rose (Dudareva et al., 2013; Tohge et al., 2013; Widhalm and Dudareva, 2015; Hirata et al., 2016; Raguso and Pichersky, 1999; Tholl, 2006; D’Auria, 2002). Although the expression of genes coding the end-product enzymes like CAD and CCR remained constant, the elevated CpPAL expression may enhance substate availability through increased activity of PAL enzyme. This likely supports the higher formation rates of certain benzenoids/phenylpropanoids in flowers of drought-stressed plants by supplying these enzymes with more substrate to act upon. In case of the monoterpene compound linalool, we found a tentative increase in the expression level of CpTPS, which may partially explain the observed higher emission rate in drought than control flowers. However, it is also possible that other upstream genes involved in the biosynthesis of linalool (such as 1-deoxy-D-xylulose 5-phosphate synthase or geranyl diphosphate synthase; Dudareva et al., 2013), which were not included in our analysis, may account for this observation. Our finding of the consistent expression levels of the negative control gene CpBEBT across control and drought-stressed flower samples, explains the similar emission rates of benzyl benzoate under both conditions. Conclusion: This study for the first time reports the impacts of drought stress on both the biosynthesis and emission rates of flower scent compounds. The observed increase in the emissions of several volatile compounds on a per flower weight basis under drought stress in Styrian oil pumpkin plants can, in part, be explained by higher expression levels of several genes (obtained from de novo transcriptomics data) potentially involved in their biosynthesis. These data pave ways for exploring functional links between the increased expression rate of these genes and the emission rate of the related volatiles, and for exploring to what extents volatile emission rates are determined by expression rates of involved pathway genes. Author contributions MB: Conceptualization; Funding acquisition; Methodology; Data curation; Formal analysis; Investigation; Project administration; Visualization; Writing-original draft; Writing-review & editing. MCH: Methodology; Formal analysis; Writing-original draft (parts of Method section); Writing-review & editing. RT: Conceptualization, Methodology; Funding acquisition; Data curation; Writing-review & editing. SD: Conceptualization; Funding acquisition; Project administration; Validation; Writing-review & editing. Acknowledgement This research work was funded in whole or in part by the Austrian Science Fund (FWF) (doi: 10.55776/M3233). We thank the gardeners at the Botanical Garden (Salzburg University) for their help in maintaining the experimental plants in the greenhouse. Roman Fuchs (Salzburg University) for his technical assistance in scent analysis. 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Insects , 13 (11). https://doi.org/10.3390/insects13110973 Information & Authors Information Version history V1 Version 1 15 July 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Keywords biosynthetic pathway genes drought stress pumpkins scent volatiles secondary metabolism volatile emissions Authors Affiliations Monica Barman 0000-0003-1406-4809 [email protected] Paris Lodron Universitat Salzburg View all articles by this author Marion Christine Hoepflinger Paris Lodron Universitat Salzburg View all articles by this author Raimund Tenhaken Paris Lodron Universitat Salzburg View all articles by this author Stefan Dötterl Paris Lodron Universitat Salzburg View all articles by this author Metrics & Citations Metrics Article Usage 231 views 232 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Monica Barman, Marion Christine Hoepflinger, Raimund Tenhaken, et al. Drought stress selectively increases the expression levels of scent-related genes and the emission rates of scent compounds in flowers of Styrian oil pumpkin. Authorea . 15 July 2025. DOI: https://doi.org/10.22541/au.175255568.86700619/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu . 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