Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
Environ Microbiol. 2014 Mar;16(3):788-801. doi: 10.1111/1462-2920.12204. Epub 2013 Jul 30.
Gti1/Pac2 are conserved family proteins that regulate morphogenic transition in yeasts such as Schizosaccharomyces pombe and Candida albicans, and they also control toxin production and pathogenicity in filamentous fungus Fusarium graminearum. To test the functions of Gti1/Pac2 paralogues MoGti1 and MoPac2 in the rice blast fungus Magnaporthe oryzae, we generated respective ΔMogti1 and ΔMopac2 mutant strains. We found that MoGti1 and MoPac2 exhibit shared and distinct roles in hyphal growth, conidiation, sexual reproduction, stress responses, surface hydrophobility, invasive hyphal growth and pathogenicity. Consistent with the putative conserved function of MoGti1, we showed that MoGti1-GFP is localized to the nucleus, whereas MoPac2-GFP is mainly found in the cytoplasm. In addition, we provided evidence that the nuclear localization of MoGti1 could be subject to regulation by MoPmk1 mitogen-activated protein kinase. Moreover, we found that the reduced pathogenicity in the ΔMopac2 mutant corresponds with an increased expression of plant defence genes, including PR1a, AOS2, LOX1, PAD4, and CHT1. Taken together, our studies provide a comprehensive analysis of two similar but distinct Gti1/Pac2 family proteins in M. oryzae, which underlines the important yet conserved functions of these family proteins in plant pathogenic fungi.
Gti1/Pac2 是保守的家族蛋白，它们在酿酒酵母（如 Schizosaccharomyces pombe 和 Candida albicans）中调节形态发生转变，还控制丝状真菌禾谷镰刀菌（Fusarium graminearum）中的毒素产生和致病性。为了测试 Gti1/Pac2 同源物 MoGti1 和 MoPac2 在稻瘟病菌（Magnaporthe oryzae）中的功能，我们生成了相应的ΔMogti1 和ΔMopac2 突变菌株。我们发现 MoGti1 和 MoPac2 在菌丝生长、分生孢子形成、有性生殖、应激反应、表面疏水性、侵袭性菌丝生长和致病性方面表现出共同和独特的作用。与 MoGti1 的假定保守功能一致，我们表明 MoGti1-GFP 定位于细胞核，而 MoPac2-GFP 主要存在于细胞质中。此外，我们提供的证据表明，MoGti1 的核定位可能受到 MoPmk1 丝裂原活化蛋白激酶的调节。此外，我们发现 ΔMopac2 突变体的致病性降低与植物防御基因（包括 PR1a、AOS2、LOX1、PAD4 和 CHT1）的表达增加相对应。总之，我们的研究提供了对 M. oryzae 中两种相似但不同的 Gti1/Pac2 家族蛋白的全面分析，强调了这些家族蛋白在植物病原真菌中的重要但保守的功能。
