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 Prunus species 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) and water deficit (WD) conditions. We combined physiological, lipidomics, and transcriptomics analyses to elucidate lipid dynamics in rootstock leaves and roots when coping drought. Data showed that R40 genotype possessed a higher stomatal conductance and photosynthetic rate under WD conditions. Lipidomic profiling indicated that most of differences were found in leaves between both genotypes. Under WD conditions, R40 genotype showed a higher number of lipids accumulated, such as ceramides, unsaturated fatty acids, and triacylglycerols. Also, when comparing WW and WD conditions, 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 genes showed that the R20 genotype were more responsive to WD, decreasing the expression of these transcripts. A decrease in fatty acid biosynthesis and desaturation was induced in the R20 genotype under WD, while the R40 genotype showed an increased expression of genes associated mainly with biosynthesis of fatty acids and triacylglycerol.