微管结合蛋白的泛素化降解在乙烯诱导番茄果实发育成熟过程中的作用机制

Senescence hormone ethylene is extensively involved in various processes of plant growth and development. One of its most important roles is to promote the ripening of tomato fruits which were investigated by abundant studies. Our primary research indicated that ethylene could induce proteasome-mediated degradation of the microtubule end-binding protein EB1, which is responsible for microtubule dynamics and might be a key protein to crosslink the microtubule with ethylene response pathway. The altered microtubule dynamics resulting from EB1 degradation might affect the biosynthesis of cell wall, the regulation of calcium concentration, the organization and trafficking of endomembrane system, which are all possibly involved in ethylene signal transduction. To date, little is known about the influence of microtubule dynamics on development and ripening of tomato fruits. In this propose, we combine the usage of exogenous microtubule-disrupting drugs and the method of genetic modification to figure out the biological role that ethylene-induced degradation of EB1 plays in the development and ripening of tomato fruits and possibly, in the biosynthesis of cell wall. Eventually, we aim to develop a novel method to prolong shelf life of tomato fruits.

衰老激素乙烯广泛参与植物生长发育过程，其中乙烯诱导番茄果实成熟的作用机制一直是国内外研究的热点之一。本项目前期研究结果表明乙烯可以诱导微管正末端结合蛋白EB1的泛素化降解，该结果揭示了乙烯信号作用于微管细胞骨架的第一个靶蛋白。微管的动态性主要由微管结合蛋白调控，EB1的降解可能是乙烯调控微管动态性的关键步骤。微管的动态性改变可能会干扰细胞壁的合成、胞内钙离子浓度的调控以及内膜系统的组织和运输，从而影响乙烯下游的信号转导。目前，国际上对于微管如何调控番茄果实发育成熟的研究还是空白。本项目用外源微管干扰药物处理结合分子生物学和基因工程的方法，研究EB1的降解在乙烯诱导番茄果实发育和成熟过程中的作用机制，以及微管动态性改变对番茄果实细胞壁合成的潜在影响，为提高番茄果实采后贮藏时间提供新的思路和方法。