衰老是叶片发育的最后阶段，其启动及进程调控受诸多内外因素影响。小麦生长后期叶片衰老与籽粒形成和灌浆成熟同步进行，叶片早衰严重影响产量和品质，而延长叶片功能期、延缓早衰则显著改善主要产量品质性状。本课题组鉴定出的两个衰老相关转录因子TaWRKYA和TaWRKYB定位于细胞核中，具有转录激活活性。在叶片自然衰老和黑暗诱导的衰老过程中上调表达，它们过表达导致拟南芥叶片提前衰老。本项目拟通过衰老信号诱导下的基因表达水平分析、靶基因及调控网络分析、过表达和CRISPR/Cas9转基因材料表型分析，揭示WRKY介导的衰老信号途径、靶基因作用位点，探讨其调控叶片衰老的分子机理。本项目预期研究结果将揭示WRKY参与小麦叶片衰老调控的分子机理，为小麦育种和遗传改良提供重要的理论依据。

Senescence, the last stage of leaf development, is a complex process regulated by multiple genetical and biochemical pathways. The initiation and process of senescence are controlled by an array of external and internal factors. Leaf senescence is happening with wheat grain filling simultaneously at late development stage. Precocious leaf senescence seriously affects wheat yield and grain quality, while extended leaf functional period and delayed leaf senescence can significantly improve yield and quality traits. Two senescence-associated WRKY transcription factors, TaWRKYA and TaWRKYB were identified in our previous study. They are localized in nucleus, and showed transcription activation activity in yeast cells. TaWRKYA and TaWRKYB were up-regulated during natural- and dark induced- leaf senescence process. Over-expression of these two genes caused precocious leaf senescence in Arabidopsis. In this study, their transcriptome changes under various senescence signal induction will be detected. DNA binding sites and their interaction proteins will be analyzed. We will use over-expression transgenic plants, CRISPR/Cas9 transgenic plants, and wild-type plants to analyze the phenotypes. The senescence-associated signal transduction and regulation pathways will be illustrated. The results of this project will help us to understand function of these transcription factors on regulation of wheat leaf senescence, to elucidate the molecular mechanisms of leaf senescence. This study may also contribute to efficient manipulation in wheat breeding and genetic improvement.