Plants adopt optimal tolerance strategies depending on the intensity and duration of stress. Retaining water is a priority under short-term drought conditions, whereas maintaining growth and reproduction processes takes precedence over survival under conditions of prolonged drought. However, the mechanism underlying changes in the stress response depending on the degree of drought is unclear. Here we report that SnRK2-substrate 1 (SNS1) is involved in this growth regulation under conditions of drought stress. SNS1 is phosphorylated and stabilized by SnRK2 protein kinases reflecting drought conditions. It contributes to the maintenance of growth and promotion of flowering as drought escape by repressing stress-responsive genes and inducing FLOWERING LOCUS T (FT) expression, respectively. SNS1 interacts with the histone methylation reader proteins MORF Related Gene 1 (MRG1) and MRG2, and the SNS1-MRG1/2 module cooperatively regulates ABA response. Taken together, these observations suggest that the phosphorylation and accumulation of SNS1 in plants reflect the intensity and duration of stress and can serve as a molecular scale for maintaining growth and adopting optimal drought tolerance strategies under stress conditions.

中文翻译：

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磷酸化 SnRK2-底物 1 的积累促进拟南芥逃避干旱

植物根据胁迫的强度和持续时间采取最佳的耐受策略。在短期干旱条件下，保持水分是首要任务，而在长期干旱条件下，维持生长和繁殖过程则优先于生存。然而，干旱程度引起的应激反应变化的机制尚不清楚。在这里，我们报道了 SnRK2-substrate 1 (SNS1) 在干旱胁迫条件下参与这种生长调节。SNS1 被 SnRK2 蛋白激酶磷酸化并稳定，反映了干旱条件。它分别通过抑制应激反应基因和诱导 FLOWERING LOCUS T (FT) 表达，有助于在干旱逃避时维持生长和促进开花。SNS1 与组蛋白甲基化读取蛋白 MORF 相关基因 1 (MRG1) 和 MRG2 相互作用，并且 SNS1-MRG1/2 模块协同调节 ABA 反应。综上所述，这些观察结果表明，植物中 SNS1 的磷酸化和积累反映了胁迫的强度和持续时间，并且可以作为在胁迫条件下维持生长和采取最佳耐旱策略的分子尺度。