中文摘要：

钙离子是非常重要的第二信使，钙离子信号途径几乎参与到细胞生长发育过程中的各个过程。本研究中主要通过同源置换的基因敲除方法对稻瘟病菌中依赖钙离子／钙调蛋白的蛋白激酶激酶2（MoCMKK2）基因的功能进行了分析。结果发现，MoCMKK2基因缺失突变体的产孢量显著上升；而在致病性、菌丝生长速率、饥饿条件下的生长、分生孢子萌发率和附着孢形成率等方面跟野生型没有差别。上述结果显示，该基因是一个影响产孢量的负调控基因。这一发现为后续稻瘟菌钙离子信号途径相关基因的研究打下了基础。

英文摘要：

Calicium is an important intracellular second messenger and the Ca^2＋-signal transduction pathway is involved nearly every aspects of the cellular signal transduction network. In this study, the function of a ca/cium/calmodulin-dependent protein kinase kinase 2 （MoCMKK2） gene in the development of the rice blast fungus Magnaporthe oryzae was studied with a targeted gene disruption method. The sporulation of the null mutant was dramatically increased; however, the pathogenicity, mycelial growth rates, mycelial growth under starvation, conidial germination, appressorium formation and mating test of the MoCMKK2 null mutant were comparable with those of the wild-type strain. These data suggest that the MoCMKK2 gene is a negative factor to regulate sporulation. These findings will further our understanding of the disease infection cycle of Magnaporthe oryzae.