中文摘要：

[目的]已有研究表明稻瘟菌Cdc42（MgCdc42）与酵母Cdc42（ScCdc42）高度同源,参与调控其形态分化和侵染过程,通过分析可能的MgCdc42互作蛋白,以明确这些蛋白结构和功能.[方法]用ScCdc42互作蛋白经BLAST搜索获得了稻瘟菌基因组中的相应同源物,分析了这些同源物的结构,并通过半定量RT-PCR分析MgCdc42不同突变情况下这些可能的调控蛋白及效应蛋白的表达情况.[结果]MgCdc42正显性突变后,导致所有推测互作蛋白表达量均有所提高;MgCdc42负显性突变,除MgBem1、Chm1、MgGic1表达量未见明显变化外,其余表达量均有所降低;当MgCdc42失活后,所有可能的MgCdc42调控蛋白及效应蛋白之表达量均有所降低.[结论]稻瘟菌可能存在酵母Cdc42相似的信号途径,MgCdc42在其中起着重要的调控作用.

英文摘要：

[Objective] MgCdc42 （Cdc42 in Magnaporthe grisea）, with high homology to ScCdc42 （Cdc42 in Saccharomyces cerevisiae）, has been demonstrated to involve in its morphogenesis and infection process. To further dissect the signaling network, the putative MgCdc42-interacting proteins were analyzed. [Method] ScCdc42-interacting protein sequences were first used to BLAST against the M. grisea genome database to retrieve their corresponding analogs. Subsequently, conserved domains of these proteins were compared and expression patterns of their encoding genes in different MgCdc42 mutation states were analyzed by semi-quantitative RT-PCR. [Result] All retrieved analogs of ScCdc42-interacting proteins from the M. grisea database have conserved domains as those in S. cerevisiae. Expression of their encoding genes increased in MgCdc42CA mutant, and decreased in MgCdc42KO mutant. However, MgBeml, Chml and MgGicl in MgCdc42DN mutant remained the same expression level as that in the wild type although MgBem4, MgBoi2, MgCdc24, MgGic2, MgRgal and Mst20 decreased as expected. [ Conclusion] Taking together, we conclude that there may exist a similar Cdc42 signal pathway in M.grisea as in S. cerevisiae and MgCdc42 plays a key role in the pathway.