本项目以前期发现的与白菜花粉发育密切相关，分别属于内切、外切和鼠李糖PG的3个基因（Bra013442、Bra000332、Bra037005）及其2个重复基因（Bra037678、Bra011440）为基础，针对PG基因家族成员众多、结构变异、功能分化、基因重复与冗余等问题，首先利用生物信息学数据库，对不同组织器官特别是花粉发育相关PG基因家族成员进化模式进行分析，然后采用amiRNA技术和转基因技术等，重点对3个PG基因及其2个重复基因进行生物学功能鉴定与生化特性分析，比较它们在花粉发育过程中作用模式的异同，继而对目的PG基因受抑制的转基因植株和相应拟南芥突变体进行相关基因表达分析比较，探讨相关成员间的功能冗余关系和相互协调关系。这些研究将为从整体上认识白菜等十字花科植物的PG基因家族成员在不同组织器官特别是花粉发育过程中的作用提供可供支撑的理论，为有效控制蔬菜等农作物育性提供依据。

The present project is based on our previous study on three polygalacturonase (PG) genes (Bra013442, Bra000332, Bra037005) which belong to endo-, exo- and rhamno-PGs respectively and their two duplicated genes (Bra037678, Bra011440), aiming at understanding how so many PG genes emerged during pollen development and questions about their structural variation, functional differentiation, duplication and redundancy etc. First, we will analyze the evolutionary modes of PG gene family members, and focus on those involved in pollen development using bioinformatic databases. Then, amiRNA and transgenetic technologies will be carried out to characterize the biological and biochemical functional differences of the three PG genes as well as their two duplicated ones. Other PGs related to pollen development will be analyzed in the transgenic plants and Arabidopsis mutants with expression suppressed of the target PGs in order to explore their functional redundancy and coordination. These studies will present a theory for understanding the functions of PG genes during the development of different tissues and organs, particularly during pollen development, and provide essential information for controlling fertility of Cruciferous vegetables and other crops.