大豆GmMYB1应答植物盐胁迫的表观遗传调控及其作用机制研究

The mechanism of epigenetic modification in response to environment stress becoming a research focus, while it’s rarely reported in soybean. In previous study, we identified a transcription factor GmMYB1, which was induced by both salinity stress and DNA methylation inhibitor. Under salt stress, the DNA methylation level within its promoter was significantly lower than the control, the over expression transgenic line exhibits a high salt tolerant ability. So we speculate, the expression of GmMYB1 may be regulated by epigenetic modification under salinity stress. Based on these study, we will further analyze the relation between GmMYB1’s dynamic epigenetic modification and expression under salt stress; confirm GmMYB1’s function; identify GmMYB1’s target genes then investigate its position in the stress regulatory network; define how GmMYB1 was regulated by epigenetic modification in the salt stress signal pathway. This study will contribute to understanding the relationship between epigenetic modification and salt stress response, extending the theory of salt tolerance in plants, providing a new theory and gene resource for investigating the mechanism of salinity response in plant.

表观遗传修饰在植物逆境胁迫应答中的作用机制已成为当前的研究热点，但其在大豆盐胁迫响应中的调控机制还鲜有报道。前期研究中，我们从大豆基因组中分离到了GmMYB1基因，发现它既受盐又受DNA甲基化抑制剂诱导。盐胁迫下其启动子区DNA甲基化水平明显低于对照，过表达拟南芥株系的耐盐性明显提高，初步判断，GmMYB1通过表观遗传修饰调控参与了植物盐胁迫应答过程。本项目拟在已有研究基础上，进一步分析盐胁迫下GmMYB1的表观遗传修饰与其表达的动态调控关系；确定GmMYB1在盐胁迫响应中的功能；鉴定GmMYB1作用的下游基因，并确定其在盐胁迫应答信号通路中的作用节点；明晰大豆如何通过表观遗传修饰调节GmMYB1的表达实现对盐胁迫应答信号通路的调控。本研究有助于深入认识表观遗传调控与植物盐胁迫应答的关系，进一步拓展植物耐盐的调控理论，并为抗盐作物品种的培育提供新的思路和基因资源。

表观遗传修饰在植物逆境胁迫应答中起着重要的调控作用。本研究确定了GmMYB1在盐胁迫响应中的功能，发现GmMYB1过表达后显著增加转基因拟南芥的耐盐能力；分析了表观遗传修饰对GmMYB1应答盐胁迫过程中表达的动态调控关系；利用生化分析鉴定了GmMYB1作用的下游关键基因，发现GmMYB1可通过影响ROS清除及盐胁迫关键转录因子基因RD22、RD29A等基因的表达来调控转基因拟南芥的耐盐能力；明晰了大豆如何通过表观遗传修饰调节GmMYB1的表达实现对盐胁迫应答信号通路的调控。本研究有助于深入认识表观遗传调控与植物盐胁迫应答的关系，进一步拓展植物耐盐的调控理论，并为抗盐作物品种的培育提供新的思路和基因资源。