Integration of lipidomics and transcriptomics provides new insights into lipid metabolism in response to water deficit in Prunus spp. rootstock leaves

The mechanisms underlying the role of lipids in the response to water deficit in Prunusspecies have not yet been elucidated. To investigate these, a drought-tolerant rootstock(R40) and a drought-sensitive rootstock (R20) were exposed to well-watered (WW) andwater deficit (WD) conditions. We combined physiological, lipidomics, andtranscriptomics to elucidate lipid dynamics in rootstock leaves and roots when copingdrought. Data showed that R40 genotype possessed a higher stomatal conductanceand photosynthetic rate under WD conditions. Lipidomic profiling indicated that most ofdifferences were found in leaves between both genotypes. Under WD conditions, R40genotype showed a higher number of lipids accumulated, such as ceramides,unsaturated fatty acids, and triacylglycerols. Also, when comparing WW and WDconditions, we observed that drought induced major changes in the R20 genotype.Interestingly, WD reduced the number of accumulated compounds, suggesting a lipid remodeling associated with degradation. Transcriptomic analysis of lipid-related genesshowed that the R20 genotype were more responsive to WD, decreasing the expressionof these transcripts. A decrease in fatty acid biosynthesis and desaturation was inducedin the R20 genotype under WD, while the R40 genotype showed an increasedexpression of genes associated mainly with biosynthesis of fatty acids andtriacylglycerol.