植物衰老是一受到复杂而精细调控的正常发育过程，对生命的延续和进化都具有积极意义。然而，早衰会导致植物叶片过早丧失光合同化功能，减少籽粒干物质的积累，严重影响作物的产量和品质。因此，揭示作物衰老的分子调控机制具有重要的理论和实践意义。在过去几年中，我们通过对水稻激活标签突变体库的高通量筛选，获得273份早衰突变体，其中ps1-D是最具代表性的显性激活突变体。研究发现，PS1不仅在年龄介导的衰老中发挥关键调控作用，在ABA介导的衰老中也发挥重要作用，因此，PS1可能是衰老信号通路中非常重要的节点基因。本项目拟以PS1为核心，通过酵母双杂、转录组和ChIP等手段寻找PS1下游靶基因，同时利用筛选获得的其它突变体，结合水稻核心种质重测序与衰老性状的关联分析，克隆鉴定新的衰老调控关键位点，利用遗传学、分子生物学、基因组学及生物信息学等手段，研究水稻衰老调控的分子机制，进而构建水稻衰老的分子调控网络。

Leaf senescence is an integral part of the final stages of plant development that is controlled by a fine-tuned, complex regulatory network. Leaf senescence facilitates both hydrolysis and the recycling of nutrients from source to sink tissues in order to increase reproductive success. Thus, plant senescence is not a passive process, rather a developmentally programmed procedure that has a strong adaptive advantage. However, premature leaf senescence is one of the primary factors that influence the yield stability of rice, particularly in hybrid rice production. Compared to the model plant Arabidopsis, the identification of key senescence associated genes (SAGs) in rice and their cognate molecular regulatory mechanisms has only just begun. Similarly, the majority of the SAGs identified to date have only been shown to be involved in chlorophyll breakdown and degradation. Given that there is likely to be a significant level of gene redundancy in the complex pathways integral to the senescence process, it is difficult to identify the key regulators of leaf senescence using loss-of-function mutants. In order to uncover key genes controlling leaf senescence in rice, we have made a large-scale screening of our gain-of-function mutant population, and more than 273 independent lines with altered senescence phenotypes were identified. ps1-D is one of the gain-of-function mutants, which demonstrated obvious premature leaf senescence phenotype. PS1 was tightly linked with the onset of leaf senescence in an age-dependent manner, and functions as an important linker between ABA and leaf senescence in rice. Therefore, we postulated that PS1 plays a key role in initiation of leaf senescence. This project will give further detailed analysis of senescence process be based on the previous studies by Y2H, microarray analysis and ChIP-seq to determine the position of PS1 in the network of rice senescence control. In addition, genome-wide association studies (GWAS) will be carried out for senescence agronomic trait with rice minicore collection. The results obtained will help us to get further understanding on the complex network of senescence regulation in rice.