State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310029, China.
Microbiol Res. 2010 Jul 20;165(5):402-10. doi: 10.1016/j.micres.2009.08.007. Epub 2009 Oct 17.
Ca(2+) is a second messenger in pathways that transduce external signals and activate cellular processes in plants and animals. Ca(2+)-mediated signal transduction is involved in key pathways that contribute to a variety of fundamental physiological processes in eukaryotic cells. However, little is known about the molecular mechanisms of Ca(2+)-mediated signal transduction in filamentous fungi. In this study, the MoCMK1 gene, encoding a putative Ca(2+)/calmodulin-dependent kinase, was identified in the rice blast fungus Magnaporthe oryzae. Three MoCMK1 deletion mutants were obtained by a targeted gene replacement. Colonies of the MoCMK1 mutants had sparse aerial hyphae and fewer conidia than the wild-type strain on complete medium. Conidial germination and appressorial formation were delayed in the DeltaMocmk1 mutants. In spray inoculation tests, DeltaMocmk1 mutants exhibited a weakened ability to infect the susceptible rice cultivar CO-39, compared to the wild-type strain Guy11. These results showed that MoCMK1 plays key roles in the pathogenicity of the rice blast fungus.
钙离子（Ca(2+)）是一种第二信使，可在动植物中将外部信号转导并激活细胞过程的途径中发挥作用。Ca(2+)-介导的信号转导参与了有助于真核细胞中各种基本生理过程的关键途径。然而，关于丝状真菌中 Ca(2+)-介导的信号转导的分子机制知之甚少。在这项研究中，从稻瘟病菌 Magnaporthe oryzae 中鉴定出编码一个假定的 Ca(2+)/钙调蛋白依赖性激酶的 MoCMK1 基因。通过靶向基因替换获得了三个 MoCMK1 缺失突变体。与野生型菌株相比，MoCMK1 突变体在完全培养基上的气生菌丝稀疏，分生孢子较少。DeltaMocmk1 突变体中的分生孢子萌发和附着胞形成延迟。在喷雾接种试验中，与野生型菌株 Guy11 相比，DeltaMocmk1 突变体感染易感水稻品种 CO-39 的能力减弱。这些结果表明 MoCMK1 在稻瘟病菌的致病性中发挥关键作用。
