Water deficit (WD) leads to significant phenotypic changes in crops resulting from complex stress regulation mechanisms involving responses at the physiological, biochemical and molecular levels. Tomato growth and fruit quality have been shown to be significantly affected by WD stress. Understanding the molecular mechanism underlying response to WD is crucial to develop tomato cultivars with relatively high performance under low watering conditions. Transcriptome response to WD was investigated through the RNA sequencing of fruit and leaves in eight accessions grown under two irrigation conditions, in order to get insight into the complex genetic regulation of WD response in tomato. Significant differences in genotype WD response were first observed at the phenotypic level for fruit composition and plant development traits. At the transcriptome level, a total of 14,065 differentially expressed genes (DEGs) in response to WD were detected, among which 7393 (53%) and 11,059 (79%) were genotype- and organ-specific, respectively. Water deficit induced transcriptome variations much stronger in leaves than in fruit. A significant effect of the genetic background on expression variation was observed compared to the WD effect, along with the presence of a set of genes showing a significant genotype × watering regime interaction. Integrating the DEGs with previously identified WD response quantitative trait loci (QTLs) mapped in a multi-parental population derived from the crossing of the eight genotypes narrowed the candidate gene lists to within the confidence intervals surrounding the QTLs. The results present valuable resources for further study to decipher the genetic determinants of tomato response to WD.

中文翻译：

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QTL、转录​​组和多态性研究的整合揭示了番茄水分胁迫反应的候选基因

水分亏缺 (WD) 导致作物显着的表型变化，这是由于复杂的应激调节机制涉及生理、生化和分子水平的反应。番茄生长和果实质量已被证明受到 WD 胁迫的显着影响。了解对 WD 响应的分子机制对于在低浇水条件下开发具有相对较高性能的番茄品种至关重要。通过对在两种灌溉条件下生长的 8 个种质中的果实和叶子进行 RNA 测序，研究了对 WD 的转录组响应，以深入了解番茄 WD 响应的复杂遗传调控。首先在果实组成和植物发育性状的表型水平上观察到基因型 WD 反应的显着差异。在转录组水平上，共检测到 14,065 个响应 WD 的差异表达基因 (DEG)，其中分别有 7393 (53%) 和 11,059 (79%) 个基因型和器官特异性。水分亏缺引起的转录组变异在叶子中比在果实中强得多。与 WD 效应相比，观察到遗传背景对表达变异的显着影响，以及一组基因的存在，这些基因显示出显着的基因型 × 浇水制度相互作用。将 DEG 与先前确定的 WD 响应数量性状基因座 (QTL) 整合到一个多亲本群体中，这些基因座是从八种基因型的杂交中获得的，从而将候选基因列表缩小到围绕 QTL 的置信区间内。