Monocarpic senescence, characterized by whole-plant senescence following a single flowering phase, is widespread in seed plants, particularly in crops, determining seed harvest time and quality. However, how external and internal signals are systemically integrated into monocarpic senescence remains largely unknown. Here, we report that the transcription factor WRKY1 plays essential roles in multiple key steps of monocarpic senescence. expression is induced by age, salicylic acid (SA), and nitrogen (N) deficiency. Flowering and leaf senescence are accelerated in the overexpression lines but are delayed in the mutants. The combined DNA affinity purification sequencing and RNA sequencing analyses uncover the direct target genes of WRKY1. Further studies show that WRKY1 coordinately regulates three processes in monocarpic senescence: (1) suppressing gene expression to initiate flowering, (2) inducing SA biosynthesis genes to promote leaf senescence, and (3) activating the N assimilation and transport genes to trigger N remobilization. In summary, our study reveals how one stress-responsive transcription factor, WRKY1, integrates flowering, leaf senescence, and N remobilization processes into monocarpic senescence, providing important insights into plant lifetime regulation.

中文翻译：

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拟南芥WRKY1通过开花、叶片衰老和氮再利用的综合调控促进单果衰老


单果衰老以单一花期后全株衰老为特征，在种子植物中广泛存在，特别是在农作物中，决定种子收获时间和质量。然而，外部和内部信号如何系统地整合到单果衰老中仍然很大程度上未知。在这里，我们报道转录因子 WRKY1 在单果衰老的多个关键步骤中发挥重要作用。表达是由年龄、水杨酸 (SA) 和氮 (N) 缺乏诱导的。过表达品系中开花和叶子衰老加速，但突变体中开花和叶子衰老延迟。结合 DNA 亲和纯化测序和 RNA 测序分析揭示了 WRKY1 的直接靶基因。进一步的研究表明，WRKY1协调调节单果衰老的三个过程：（1）抑制基因表达以启动开花，（2）诱导SA生物合成基因以促进叶片衰老，（3）激活氮同化和转运基因以触发氮再动员。总之，我们的研究揭示了一种胁迫响应转录因子 WRKY1 如何将开花、叶片衰老和氮再动员过程整合到单果衰老中，为植物寿命调控提供了重要见解。