Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043, Marburg, Germany.
Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Str. 2, D-85350, Freising-Weihenstephan, Germany.
New Phytol. 2015 May;206(3):1116-1126. doi: 10.1111/nph.13304. Epub 2015 Jan 27.
The secreted fungal effector Pep1 is essential for penetration of the host epidermis and establishment of biotrophy in the Ustilago maydis-maize pathosystem. Previously, Pep1 was found to be an inhibitor of apoplastic plant peroxidases, which suppresses the oxidative burst, a primary immune response of the host plant and enables fungal colonization. To investigate the conservation of Pep1 in other pathogens, genomes of related smut species were screened for pep1 orthologues. Pep1 proteins were produced in Escherichia coli for functional assays. The biological function of Pep1 was tested by heterologous expression in U. maydis and Hordeum vulgare. Pep1 orthologues revealed a remarkable degree of sequence conservation, indicating that this effector might play a fundamental role in virulence of biotrophic smut fungi. Pep1 function and its role in virulence are conserved in different pathogenic fungi, even across the monocot-dicot border of host plants. The findings described in this study classify Pep1 as a phylogenetically conserved fungal core effector. Furthermore, we documented the influence of Pep1 on the disease caused by Blumeria graminis f. sp. hordei which is a non-smut-related pathosystem.
分泌的真菌效应物 Pep1 对于玉米黑粉菌-玉米病理系统中穿透宿主表皮和建立生物营养的过程是必不可少的。先前发现 Pep1 是质外体植物过氧化物酶的抑制剂，它抑制了宿主植物的氧化爆发，这是宿主植物的主要免疫反应，并使真菌能够定殖。为了研究 Pep1 在其他病原体中的保守性，筛选了相关黑粉菌物种的基因组以寻找 pep1 直系同源物。Pep1 蛋白在大肠杆菌中产生，用于功能测定。通过在玉米黑粉菌和大麦中异源表达来测试 Pep1 的生物学功能。Pep1 同源物显示出显著的序列保守性，表明该效应物可能在生物营养性黑粉菌的毒力中发挥着基本作用。Pep1 的功能及其在毒力中的作用在不同的致病真菌中是保守的，即使跨越了宿主植物的单子叶植物-双子叶植物边界。本研究中描述的发现将 Pep1 归类为系统发育保守的真菌核心效应物。此外，我们记录了 Pep1 对禾柄锈菌引起的疾病的影响，禾柄锈菌是一个与黑粉菌无关的病理系统。
