光敏色素PhyB基因调控表皮毛发生的分子机理

Plant trichomes are highly specialized epidermal cells implicated in several important functions,including transpiration control, freezing tolerance, protection against insects, diseases, and UV light. Trichomes are also of special commercial interest because they have a unique secondary metabolism, allowing the production and secretion of various useful natural compounds. Phytochrome is a pigment-protein which regulates the growth and development of plant, and plays an important role for the photomorphogenesis, however, the mechanism of PhyB on the regulation of trichome formation remains uncovered. Our previous date showed that the mutation of PhyB resulted in reduction of the number of trichomes, while overexpression of PhyB increased the number of trichomes. And this phenotype is also denpendent on red light, and PhyBs from soybean and Arabidopsis had the similar function. The results indicated that PhyB was involved in trichome initiation and development and this function is conserved in plants. This project is focusing on the mechanism of PhyB on trichome formation in soybean and Arabidopsis by studying during the formation of trichomes the relationship between PhyB and phytohormones and the control mechanism of PhyB downstream genes on the key genes related to trichome morphogenesis. The results of this project hopefully provide a new line of evidence to elucidate the mechanism of trichome formation, elucidate novel function for PhyB, and explore its application on crop production.

植物的表皮毛是高度特化的表皮细胞，与呼吸调控、抗逆（冻害、病虫害以及紫外线辐射）密切相关，同时表皮毛具有特殊的次生代谢途径，往往会产生具有重要价值的天然化合物，因而表皮毛发生的机理研究具有重要的理论和应用价值。光敏色素是植物自身合成的调节生长发育的色素蛋白，在光形态建成中承担重要的角色，但光敏色素调控植物表皮毛发生的分子机制尚不清楚。 在本研究中我们发现光敏色素基因突变导致表皮毛数量下降，过表达导致表皮毛数量的增多，这种现象是红光特异且在大豆和拟南芥中的PhyB具有类似的功能，说明光敏色素参与表皮毛发生的调节，并且在不同植物中功能保守。本课题拟在此基础上，通过分析在表皮毛发生过程中光敏色素与植物激素的关系以及光敏色素下游靶基因对表皮毛发生关键基因的调控作用，深入研究PhyB对大豆和拟南芥表皮毛发生的调节机制，为表皮毛发生机理的研究和在作物上的应用提供理论基础。