植物受体蛋白激酶EMS1和BRI1功能分化机制的研究

类受体蛋白激酶（RLK）爆发性扩增伴随着陆生植物进化，也伴随着其雌雄配子体发育的特化进程。花药作为高等植物雄配子体的产生场所，其正常发育对植物的世代交替具有重要意义。而花药的正常发育依赖于绒毡层。我们的研究表明EMS1与BRI1（RLKs）以相同的下游信号调控不同的生物学功能。EMS1作为TPD1的受体调控绒毡层的发育而BRI1作为油菜素内酯的受体几乎控制植物生长发育的各个过程。ems1和bri1突变体都不可育，但前者没有花粉、植株正常而后者有花粉、植株矮小。我们发现EMS1启动子驱动BRI1表达可以恢复bri1突变体表型但BRI1启动子驱动EMS1表达不可以恢复ems1突变体表型。因此，BRI1/EMS1的功能分化可能是BRI1表达特异（不在绒毡层）但激酶活力强而EMS1表达广泛但激酶活力弱小所致。佐证这一假说不但阐明EMS1/BRI1功能分化机理而且奠定研究RLK爆发性扩增的基础。

The explosive expansion of receptor-like protein kinases (RLKs) accompanies the evolution of land plants, as well as the specialization of the development of its male and female gametophytes. Anthers, as the place of generation of male gametophytes in higher plants, its normal development is of great significance for plant life cycles. The anther normal development depends on the tapetum. Our previous study indicates that EMS1 and BRI1 (RLKs) perform different biological functions with the same downstream signaling. EMS1, as a receptor for TPD1, regulates the development of the tapetum and BRI1 as a receptor for brassinolide, controls almost every process of plant growth and development. Neither ems1 nor bri1 mutants are fertile, but the former has no pollen, yet the plants are normal; while the latter has pollen, yet the plants are dwarf. We found that the expression of BRI1 by driven by the EMS1 promoter can rescue the phenotypes of the bri1 mutants, but the expression of EMS1 by driven by the BRI1 promoter cannot rescue the phenotypes of the ems1 mutants. Therefore, the functional differentiation of BRI1 / EMS1 may be due to the specific expression of BRI1 (not in the tapetum) with a strong kinase activity and the ubiquitous expression of EMS1 with a weak kinase activity. Ratifying this hypothesis not only clarifies the mechanism of the functional differentiation of EMS1 / BRI1 but also lays the foundation for studying the explosive expansion of other RLKs.