GSE61109
Transcriptomics and physiological analyses reveal coordinated alteration of metabolic pathways in Jatropha curcas drought tolerance
Jatropha curcas, a multipurpose plant attracting much attention due to its high oil content and quality for biofuel, is recognized as a drought tolerant species. However, this drought tolerance is still poorly characterized. This study aims to contribute to uncover the molecular background of this tolerance, with the use of a combined approach of transcriptional profiling and morphophysiological characterization along a period of water withholding (49 days) followed by rewatering (7 days). Morphophysiological measurements evidenced that J. curcas plants presented different adaptations to withstand moderate and severe drought. Thus, RNA-Seq was performed for samples collected at moderate and severe stress followed by rewatering, for both roots and leaves. Transcriptomic analysis revealed organ-specific adaptations across all investigated conditions, except under severe stress, in which the drought response of J. curcas surpassed organ-specificity by dramatic transcriptomic reorganization. These changes in gene expression were clearly evidenced by the down-regulation of genes involved in growth and water uptake, and up-regulation of osmotic adjustments and cellular homeostasis related genes. However, organ-specific variations were also detected, such as strong up-regulation of chlorophyll and trehalose metabolism in leaves. Functional validation further corroborated the differentially expression of genes coding for enzymes involved in chlorophyll metabolism, which correlates with the metabolite content of this pathway. Overall design: Two Jatropha curcas accessions were submitted to moderate and severe drought stress (water withholding) followed by recovery (3d re-watering), transcriptomic profiles were assessed by RNA-Seq.