植物生长和免疫抗病的平衡是作物增产抗病的关键，解析其分子调控机理对培育高产抗病的作物品种具有巨大的指导意义。申请人前期的研究工作显示bHLH转录因子HBI1在调控植物生长和免疫抗病的平衡中起着关键的调控作用。植物生长信号包括生长素，赤霉素和油菜素内酯在蛋白水平上通过一个HLH/bHLH的拮抗传递链来激活HBI1，而病原菌可以在转录水平上抑制HBI1的活性。通过调控HBI1的活性，植物十分精确的整合了内外源信号，实现了植物生长和免疫的动态平衡。但HBI1如何动态调节植物生长和免疫平衡的分子机制并不是很清楚。在本项目中申请人围绕“植物生长和免疫平衡调控的分子机理”这一关键科学问题，以HBI1的功能研究为切入口，通过系统研究HBI1的互作蛋白和HBI1下游靶基因的功能研究，来逐步阐明HBI1整合内外源信号调控植物生长和免疫抗病动态平衡，进而为我们下一步高产抗病育种提供扎实的理论基础和技术保障。

Plants need to finely balance resources allocated to growth and immunity to achieve optimal fitness. The trade-off between growth and immunity are crucial for high yield and disease resistance of crops. Recently our research results showed that bHLH transcription factor HBI1 antagonistically regulate the growth and immunity. Plant growth-promoting hormones Auxin, GA and BR enhanced the HBI1 activity through the PRE-IBH1-HBI1 tripartite HLH/bHLH cascade, whereas PAMPs repressed HBI1 transcription with unknown mechanisms. HBI1 integrates the hormonal and environmental signals to regulate the tradeoff between growth and immunity. In order to systemically investigate the functions of HBI1, we will screen and functional study of HBI1-interacting proteins, and the downstream of HBI1-binding and -regulating target genes. Our long-time goal is to define the molecular mechanisms by which HBI1-regulating network integrates multiple signals to regulate the trade-off between plant growth and immunity, and provides some new tools for breeding high-yield and disease resistance crops.