中文摘要：

为了解叶锈菌侵染小麦后小G蛋白Rab2基因的表达情况,明确其与抗病性的关系,从分子水平上探讨小麦的抗叶锈病机制。以普通六倍体小麦近等基因系TcLr1和叶锈菌小种05-22-64①和05-8-63①为试验材料,构建小麦亲和与非亲和组合,利用实时定量PCR技术对小麦小G蛋白Rab2基因的表达情况进行检测。结果表明：在小麦叶锈菌侵染过程中,Rab2基因主要在侵染的前期表达迅速,随着时间的推移表达量有所下降。非亲和叶锈菌菌株可以诱导小G蛋白Rab2基因表达量的升高,而亲和叶锈菌菌株抑制小G蛋白Rab2基因的表达。由此表明,小G蛋白可能与寄主和病原物的亲和程度有着直接的关系。

英文摘要：

Wheat leaf rust disease caused by wheat leaf rust （Puccinia triticina） is one of the most important diseases which have led to heavy losses to the wheat production in the world,and it also is a main factor influencing the wheat production in our country. The application of the disease resistant varieties and increasing host plant resistance are the most promising ways to control this disease,which based on the fully understanding of the resistant mechanisms. In recent years,the regulation channel of small G protein has become a hot issue of research of plant resistant mechanism. The small GTP-binding protein Rab,which consists of about two hundred amino acids,is the largest one of small GTP-binding proteins sub-families and plays an very important role in vesicular transport in eukaryotic cells. The purpose of this study is to understand the expression of the small G protein Rab2 gene in the wheat infected with wheat leaf rust （ Puccinia triticina） ,and definite the relationship between the Rab2 and the disease resistance,to investigate the resistance mechanism of wheat leaf rust in the molecular level. In this study,the near-isogenic lines of the common hexaploid wheat TcLr1 and leaf rust Race 05-22-64 ①and 05-8-63① are used to build the compatible combi- nations and the incompatible combinations,then RNA were extracted at different time points and the first strand of cD- NA were synthesized by reverse transcription in vitro. Rab2 gene expression were analyzed by real-time fluorescence quantitative PCR. As results,in the process of infection by wheat leaf rust （puccinia triticina） ,Rab2 gene significantly expressed only in six hours after inoculation and reached the highest expression point at twelve hours after inoculation,and in the following hours Rab2 gene expression decreased. It means Rab2 gene is mainly expressed in the early stage of infection,while declines with time prolonged. The incompatible combinations can upregulate the expression of the small GTP-binding protein Rab2 gene,while th