拟南芥JMJ24和JMJ28在ABA调节的幼苗早期发育中的作用机理研究

种子萌发和后续幼苗发育是植物生长发育过程中的重要环节。受到ABA调节的子叶变绿的过程标志着植物由异养到自养的转变， 是幼苗发育开始的重要指标。 虽然ABI5是这一过程中的重要调节因子，但是其具体的作用机制以及其是否是唯一的调节因子目前并不十分清楚。申请人拟通过对JUMONJI家族成员 JMJ24和JMJ28的T-DNA插入突变体及高表达植物的生理表型及分子表型的分析，确认其在ABA调节的子叶变绿过程中的作用以及其是否通过ABI5不依赖的途径起作用，进而通过高通量测序的方法在基因组水平找到受到JMJ24和JMJ28直接调节的基因，解释其可能的作用方式；并利用筛选结合蛋白的方法以及筛选双突变体抑制子的方法对JMJ24和JMJ28的作用机理进行研究，为进一步阐明ABA参与的植物由异养向自养的转变过程的调节机制提供更多证据。

Seed germination and post-germinative growth are key developmental events in higher plant life cycle. One of the landmarks for post-germinative growth is cotyledon greening, which marks the switch of the new life from the heterotrophic stage to autotrophic organism. Cotyledon greening is primarily regulated by ABA signaling pathway through transcription factor ABI5. But how ABI5 regulates this phase transition and if there is ABI5 independent pathway is largely unclear. JMJ24 and JMJ28 are members of plant JUMONJI histone demethylase family with unknown function. By analyzing the physiological and molecular phenotypes of the T-DNA knockout mutants and overexpression plants, we will be able to clarify if JMJ24 and JMJ28 function in ABA regulated cotyledon greening as well as if their function is ABI5 dependent. Furthermore, we will use next-generation sequencing techniques to analyze JMJ24 and JMJ28 directly regulated genes in genome level. We will use yeast-two-hybrid screening and coimmunoprecipitaion methods to identify JMJ24 interacting protein; we will also use genetic screening method to look for supressors of jmj24;jmj28 double mutants. By analyzing the functions of JMJ24 interacting proteins and double mutant supressors, we will be able to understand the mechanism of JMJ24 and JMJ28 in ABA regulated cotyledon greening process and provide more evidences to clarify how is the heterotrophic to autotrophic checkpoint regulated in higher plants.