Plants are frequently exposed to environmental challenges. Responses to sub-lethal abiotic stress combinations are complex and often distinct from responses to individual stresses and remain poorly understood. Investigating traits and molecular factors mediating acclimation to stress combinations is essential for the development of climate change-resilient field crops. Here, we studied the morphological, physiological, and molecular responses of Arabidopsis thaliana to i) co-occurring high temperature and drought and ii) flooding followed by drought, both of which have increased in frequency due to climate change, and the individual component stresses: high temperature, drought and flooding. A set of 15 physiological and morphological traits were assessed during single and combined stresses. By combining these comprehensive trait analyses with transcriptome characterization, we established the generally additive negative effects of simultaneous or sequential stresses on plant morphology and physiology compared to the corresponding individual stresses. Although drought had a mild effect on various growth, morphological and physiological traits in both stress combinations, a unique transcriptome signature emerged upon combination with high temperature simultaneously or flooding sequentially. Molecular processes identified as important for multi-stress resilience included plastid-nucleus communication, ABA signaling and photo-acclimation. Based on the RNA-seq data, a set of 39 genes was identified as potential multi-stress response regulators. Mutants were tested to validate the contribution of these genes to plant survival and phenotypic acclimation under combined stress. We confirmed the involvement of several genes in regulating phenotypic acclimation traits. Among the identified factors were EARLY FLOWERING 6 (ELF6) and ARABIDOPSIS TÓXICOS EN LEVADURA 80 (ATL80), with substantial effects on plant growth, leaf development and plant survival (wilting) during high-temperature drought and post-submergence drought, respectively.

中文翻译：

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破译拟南芥对亚致死联合和连续非生物胁迫的适应


植物经常面临环境挑战。对亚致死性非生物胁迫组合的反应很复杂，通常与对个体胁迫的反应不同，并且仍然知之甚少。研究介导适应胁迫组合的性状和分子因素对于开发适应气候变化的大田作物至关重要。在这里，我们研究了拟南芥对 i） 高温和干旱同时发生的 ii） 洪水后干旱的形态、生理和分子响应，这两者都因气候变化而增加频率，以及各个组成部分的胁迫：高温、干旱和洪水。在单一和联合应力下评估了一组 15 种生理和形态特征。通过将这些全面的性状分析与转录组表征相结合，我们确定了与相应的单个胁迫相比，同时或连续胁迫对植物形态和生理学的通常附加负面影响。尽管干旱对两种胁迫组合中的各种生长、形态和生理性状影响较小，但在与高温同时或相继泛滥结合时，出现了独特的转录组特征。被确定为对多应激恢复力很重要的分子过程包括质体-核通讯、ABA 信号传导和光驯化。根据 RNA-seq 数据，一组 39 个基因被确定为潜在的多应激反应调节因子。对突变体进行测试，以验证这些基因在联合胁迫下对植物生存和表型驯化的贡献。我们证实了几个基因参与调节表型驯化性状。 已确定的因素包括早花 6 （ELF6） 和拟南芥 EN LEVADURA 80 （ATL80），分别在高温干旱和淹没后干旱期间对植物生长、叶片发育和植物存活（枯萎）产生重大影响。