稻瘟病菌MoRho2基因功能初步分析

Functional Analysis of MoRho2 in Magnaporthe oryzae

稻瘟病菌(Magnaporthe oryzae)是研究病原真菌生长发育及致病机理的重要模式生物。Rho家族蛋白是一类具有GTP酶活性的GTP结合蛋白,在多种细胞信号转导通路中起着分子开关的作用。通过生物信息学方法分析Mo Rho2的理化性质、蛋白结构域等信息,并推测其潜在功能。为进一步明确Mo Rho2蛋白的功能,利用基因敲除技术获得Mo Rho2基因的敲除突变体。表型分析结果表明,与野生型菌株相比,Mo Rho2敲除突变体的菌丝生长速度、分生孢子形态、附着胞形态、产孢量、对植物的毒力等方面均无明显的差异,但分生孢子萌发和附着胞形成略滞后于野生型菌株。突变体能够产生正常的侵入栓并侵入洋葱表皮。综上所述,Mo Rho2基因可能参与稻瘟病菌分生孢子的萌发和附着胞的形成,结果为进一步揭示基因Mo Rho2的生物学功能奠定基础。

Rice blast fungus, Magnaporthe oryzae, is an important model for the study of the interaction between host plant and pathogenic fungus. Rho-family proteins act as molecular switches in signal transduction. In this study, we applied bioinformatics and gene knock-out techniques to study the function of MoRho2 in the fungus.Bioinformatics analysis showed that the gene had no signal peptide and transmembrane. A slight delay of conidium germination and appressorium development and a slight decrease of penetration pegs were observed in MoRho2knock-out mutant, when compared to wild-type strain.However, the mutant was not affected in growth rate,conidiation and pathogenicity, probably on account of the gene redundancy of MoRho2 in the fungal genome.Taken together, it appeared more likely that MoRho2 regulated conidium germination and appressorium development of rice blast fungus. These results would help to well understand the biological function and the molecular regulation mechanism of MoRho2.