The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 7610001, Israel (L.S.-M., Z.P.); and.
Department of Plant Sciences, University of California, Davis, Davis, CA 95616 (E.B.).
Plant Physiol. 2017 May;174(1):421-434. doi: 10.1104/pp.17.00030. Epub 2017 Mar 17.
Climate-change-driven stresses such as extreme temperatures, water deficit, and ion imbalance are projected to exacerbate and jeopardize global food security. Under field conditions, these stresses usually occur simultaneously and cause damages that exceed single stresses. Here, we investigated the transcriptional patterns and morpho-physiological acclimations of to single salinity, drought, and heat stresses, as well as their double and triple stress combinations. Hierarchical clustering analysis of morpho-physiological acclimations showed that several traits exhibited a gradually aggravating effect as plants were exposed to combined stresses. On the other hand, other morphological traits were dominated by salinity, while some physiological traits were shaped by heat stress. Response patterns of differentially expressed genes, under single and combined stresses (i.e. common stress genes), were maintained only among 37% of the genes, indicating a limited expression consistency among partially overlapping stresses. A comparison between common stress genes and genes that were uniquely expressed only under combined stresses (i.e. combination unique genes) revealed a significant shift from increased intensity to antagonistic responses, respectively. The different transcriptional signatures imply an alteration in the mode of action under combined stresses and limited ability to predict plant responses as different stresses are combined. Coexpression analysis coupled with enrichment analysis revealed that each gene subset was enriched with different biological processes. Common stress genes were enriched with known stress response pathways, while combination unique-genes were enriched with unique processes and genes with unknown functions that hold the potential to improve stress tolerance and enhance cereal productivity under suboptimal field conditions.
气候变化引起的压力，如极端温度、水分亏缺和离子失衡，预计将加剧并危及全球粮食安全。在田间条件下，这些压力通常同时发生，并造成超过单一压力的损害。在这里，我们研究了在单一盐度、干旱和热胁迫以及它们的双重和三重胁迫组合下的转录模式和形态生理适应。形态生理适应的层次聚类分析表明，随着植物暴露于复合胁迫下，几种特性表现出逐渐加重的效应。另一方面，其他形态特征由盐度主导，而一些生理特征则由热胁迫形成。在单一和复合胁迫（即共同胁迫基因）下差异表达基因的响应模式仅在 37%的基因中保持一致，这表明部分重叠胁迫之间的表达一致性有限。共同胁迫基因与仅在复合胁迫下特异表达的基因（即组合特异基因）之间的比较表明，分别从增强的强度到拮抗反应的显著转变。不同的转录特征意味着在复合胁迫下作用模式的改变，以及在不同胁迫组合时预测植物响应的能力有限。共表达分析结合富集分析表明，每个基因子集都富集了不同的生物学过程。共同胁迫基因富集了已知的应激反应途径，而组合特异基因富集了独特的过程和具有未知功能的基因，这些基因有可能在田间条件下提高耐胁迫性和提高谷物产量。
