SpoMBF1蛋白磷酸化介导的菠菜高温胁迫应答分子途径解析

Spinach (Spinacia oleracea L.) is one of the main green leaves vegetables cultivated in China. High temperature stress seriously affects the growth and development of spinach, resulting in a significant decline in yield and quality. It is important to study the molecular mechanism of high temperature response in spinach for finding molecular markers of high temperature response and applying them to spinach breeding and production. Transcription activation cofactor multiprotein bridging factor 1 (MBF1) is a key factor in response to heat stress. It activates downstream gene transcription by bridging DNA binding transcription factor and TATA-box binding protein. In this project, SpoMBF1 was identified to be phosphorylates under the induction of high temperature. On the one hand, interaction factors in upstream regulation of MBF1 were explored through yeast cDNA library screening, IP-LC/MS and co-expression analysis. On the other hand, heat-resistant target genes in downstream of MBF1 was searched through Chip-seq analysis. In the end, a molecular pathway for MBF1 to participate in regulation of spinach Heat-tolerance was identified, which provided a basis for breeding new heat-resistant varieties.

菠菜(Spinacia oleracea L.)是我国重要的绿叶蔬菜之一。高温胁迫严重影响菠菜生长发育。开展菠菜高温应答分子机理研究，对于发现高温应答分子标记，并将其应用于菠菜育种与生产实践具有重要意义。转录激活辅因子Multiprotein bridging factor 1 (MBF1)是高温胁迫应答关键核心因子，通过桥接DNA结合转录因子和TATA-box结合蛋白激活下游基因的转录。本项目利用“靶向定量磷酸化蛋白质组学”，鉴定到菠菜SpoMBF1在高温诱导下受到磷酸化调控。并以此为切入点，一方面通过结合酵母cDNA文库筛选、IP-LC/MS和共表达分析探索SpoMBF1上游的互作蛋白激酶，另一方面通过Chip-seq分析搜索SpoMBF1下游调控的耐热靶点基因，解析出一条SpoMBF1参与调控菠菜耐热性的分子途径，对于植物高温应答机理的研究和优质耐热菠菜品种的培育都有重要指导意义。

全球气温逐年升高成为农业发展的巨大威胁。菠菜（Spinacia oleracea L.）是一种耐寒不耐热的绿叶蔬菜，热胁迫严重影响菠菜生长、产量和品质。然而，菠菜响应热胁迫的分子机制鲜有报道。MBF1是一类进化高度保守的转录共激活因子，可将通用转录因子TBP与多种转录因子桥接，从而激活基因转录。MBF1可以提高植物对多种非生物胁迫的耐受性。其中，MBF1c是植物耐热性的关键调节因子，但SoMBF1是否参与菠菜耐热调控未见报道。探究菠菜不同耐热材料SoMBF1的高温应答功能，对揭示菠菜热胁迫响应的分子机制十分重要。本研究通过生物信息学、分子遗传学技术初步分析了SoMBF1s对热胁迫的响应。利用SoMBF1s转基因材料的筛选及表型分析，探究了SoMBF1s对拟南芥耐热性的影响；通过酵母单杂交及cDNA文库筛选等技术初步确定了SoMBF1c的转录调控方式及互作蛋白，初步解析了SoMBF1s基因参与菠菜高温胁迫调控的分子机制。上述研究结果为深入认识菠菜SoMBF1c的热应答功能、开展分子设计育种提供了重要信息。