In order to clarify the transcriptional regulatory network and physiological mechanisms governing leaf senescence response to drought stress in wheat, experiments were performed using two wheat varieties with contrasting drought tolerance: Fu287 (F287, a drought‐sensitive genotype) and Shannong20 (SN20, a drought‐resistant genotype). The latter has higher SPAD values, salicylic acid (SA), jasmonic acid (JA), zeatin (Z), zeatin riboside (ZR), and gibberellin (GA₃) content as well as higher expression levels of Cu/Zn‐SOD, Mn‐SOD, Fe‐SOD, POD, CAT, and APX under various water deficit conditions. Conjoint analysis of physiological and biochemical indicators and transcriptome data by weighted gene co‐expression network analysis (WGCNA) in the present study provides a useful genomic and molecular resource for studying drought adaptation in wheat. The flag leaf senescence process was changed by altering the concentration of phytohormones. SA, JA, abscisic acid (ABA), Z, ZR, and GA₃ coordinate with each other to control leaf senescence and plant adaptation under drought stress. Further, the leaf senescence process was divided into two phases: the persistence phase and the rapid loss phase. Shorter Chl_total (duration of the flag leaf being photosynthetically active), shorter Chl_per (persistence phase), reduced M (inflection point cumulative temperature when senescence rate is the maximum), decreased r_max (the maximum senescence rate), larger r₀ (the initial senescence rate), and increased r_aver (the average senescence rate) were slightly associated with low grain mass. We speculated that extending the period of the persistence phase by cultivation or chemical control measures could further increase the drought survivability and productivity of wheat.

中文翻译：

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鉴定调节小麦旗叶衰老的植物激素和候选枢纽基因对灌浆期水分亏缺胁迫的响应。

为了阐明小麦叶片衰老响应干旱胁迫的转录调控网络和生理机制，利用两个具有对比耐旱性的小麦品种：Fu287（F287，干旱敏感基因型）和山农20（SN20，干旱敏感基因型）进行了实验。耐药基因型）。后者具有较高的SPAD值、水杨酸(SA)、茉莉酸(JA)、玉米素(Z)、玉米素核苷(ZR)和赤霉素(GA 3 )含量以及较高的Cu/Zn- _SOD表达水平，不同水分亏缺条件下的Mn-SOD、Fe-SOD、POD、CAT和APX 。本研究通过加权基因共表达网络分析（WGCNA）对生理生化指标和转录组数据进行联合分析，为研究小麦的干旱适应提供了有用的基因组和分子资源。通过改变植物激素的浓度来改变旗叶衰老过程。SA、JA、脱落酸(ABA)、Z、ZR和GA ₃相互协调控制叶片衰老和植物在干旱胁迫下的适应。此外，叶片衰老过程分为两个阶段：持续阶段和快速损失阶段。_总叶绿素（旗叶光合活跃持续时间）较短，_每叶叶绿素（持续期）较短，M（衰老率最大时的拐点累积温度）降低，r _max（衰老率最大）降低，r ₀增大（初始衰老率）和增加的_raver （平均衰老率）与低谷粒质量略有相关。我们推测，通过耕作或化学防治措施延长持续期的时间可以进一步提高小麦的干旱生存能力和生产力。