拟南芥类受体激酶HSL1调控种子寿命的功能与作用机制研究

Seed longevity is an important trait from both ecological and agricultural perspectives. Mining and clarifying key genes in regulating the seed longevity and elucidating the molecular mechanism is of great significance to both plant germplasm conservation and high yield, high quality and efficient production in agriculture. Our previous work showed that disruption of Arabidopsis receptor-like kinase HAESA like 1 (HSL1) showed seed ageing phenotype. At present there is not any report about the function of HSL1. However, the homologous genes HAESA and HSL2 participate in the process of flower abscission by affecting the synthesis and modification of the cell wall. On the other hand, plant cell wall participates in the response to the biotic and abiotic stresses. Therefore, the synthesis and modification of the seed cell wall is possibly an important mechanism affecting the seed longevity. The current project will combine multidisciplinary means, to study the function of HSL1 in seed longevity, and the relationship of changes in seed longevity and the cell wall synthesis and modification of the seed; to identify the interaction protein(s) of HSL1, and to elucidate the signal pathways that HSL1 involved in affecting the seed longevity. As far as I know, this project is the first to study the function of a key regulatory factor and its molecular mechanism in seed longevity. The study will theoretically elucidate the new mechanism in regulating seed longevity, and practically provide new gene resources to improve the seed longevity in plant.

种子寿命是生态学上与农业上具有双重意义的重要性状。寻找并明确调控种子寿命的关键基因的功能与作用机制，对于植物种质资源的保存和高产优质高效农业生产具有重要的意义。我们前期发现，拟南芥类受体激酶HAESA like 1 (HSL1)基因的失活种子寿命显著下降。目前尚无HSL1功能的任何报道，但其同源基因HAESA和HSL2参与器官脱落过程中细胞壁的合成与修饰。由于细胞壁参与植物体对各种生物和非生物逆境的响应，因此，种子细胞壁的合成与修饰可能是影响种子寿命的一个很重要的机制。本项目拟采用多学科的手段，研究HSL1在调控种子寿命中的作用；以及这种作用与种子内细胞壁合成与修饰的关系；筛选出HSL1的互作蛋白、解析HSL1影响种子寿命可能涉及到的信号通路。本项目从蛋白激酶的角度研究调控类因子在种子寿命中的功能与作用机制，理论上将阐明种子寿命调控的新机制，实践上为调控种子寿命提供新的关键基因资源。

种子寿命是生态学上和农业上具有双重意义的重要性状。寻找并明确调控种子寿命关键基因，特别是调控基因的作用与机制具有重要的意义。前期我们研究发现，拟南芥编码类受体激酶 HAESA like 1 (HSL1)基因的T-DNA 插入突变体hsl1 种子寿命显著下降。本项目将在此基础上，构建了拟南芥hsl1的回复突变和过表达株系，进一步证实HSL1正调控种子寿命。种子钌红染色及细胞壁成分分析显示，HSL1调控种子寿命与种皮分泌果胶含量相关，但与分泌果胶粘液的面积、种皮其他细胞壁成分没有关系。构建拟南芥pHSL1：GUS株系，GUS染色显示，HSL1主要在花萼、花梗及发育各阶段的种子中表达，在成熟种子及萌发的各阶段种子的胚中高表达。利用酵母双杂的方法筛选到推定的互作蛋白20余个。根据互作蛋白基因的组织表达特异性构建其中10个互作蛋白的质粒一对一验证，最终获得核心互作蛋白3个。项目执行期间（两年），课题组成员积极参加学术交流3人次（不包括疫情期间的网络会议），培养硕士生4名、博士生2名。已发表论文2篇，其中SCI期刊1篇，已投稿SCI期刊论文1篇。