Fabre Francis, Bormann Joerg, Urbach Serge, Roche Sylvie, Langin Thierry, Bonhomme Ludovic
Université Clermont Auvergne, INRAE, UMR 1095 Genetics, Diversity and Ecophysiology of Cereals, Clermont-Ferrand, France.
Department of Molecular Phytopathology, Institute of Plant Science and Microbiology, University of Hamburg, Hamburg, Germany.
Front Microbiol. 2019 Dec 11;10:2857. doi: 10.3389/fmicb.2019.02857. eCollection 2019.
Fusarium head blight (FHB), caused mainly by , is the foremost destructive disease of cereals worldwide. Effector-like molecules produced by play key roles in the infection process and are assumed to be one of the essential components of the pathogen's aggressiveness. However, their nature and role in the disease are still largely misunderstood. As a mean to provide relevant information about the molecular determinism of aggressiveness, we surveyed three strains on three wheat cultivars contrasted by their susceptibility to FHB. strains revealed large differences in aggressiveness which were mostly unchanged when facing hosts of contrasted susceptibility, suggesting that their behavior rely on intrinsic determinants. Surveying the fungal mass progress and the mycotoxin production rate in the spikes did not evidence any simple relationship with aggressiveness differences, while clues were found through a qualitative and quantitative characterization of the three strain proteomes established especially with regards to early synthesized putative effectors. Independently of the wheat cultivar, the three strains produced systematically the same protein set during the infection but substantial differences in their abundance enabled the categorization of fungal aggressiveness. Overall, our findings show that the contrasts in aggressiveness were not based on the existence of strain-specific molecules but rather on the ability of the strain to ensure their sufficient accumulation. Protein abundance variance was mostly driven by the strain genetics and part was also influenced by the host cultivar but strain by cultivar interactions were marginally detected, depicting that strain-specific protein accumulations did not depend on the host cultivar. All these data provide new knowledge on fungal aggressiveness determinants and provide a resourceful repertoire of candidate effector proteins to guide further research.
小麦赤霉病（FHB）主要由[病原菌名称未给出]引起，是全球范围内对谷物最具破坏性的病害。[病原菌名称未给出]产生的类效应分子在感染过程中起关键作用，被认为是病原菌致病性的重要组成部分之一。然而，它们的性质和在病害中的作用仍大多未被理解。为了提供有关[病原菌名称未给出]致病性分子决定因素的相关信息，我们在三个对FHB敏感性不同的小麦品种上研究了三种[病原菌名称未给出]菌株。这些菌株在致病性上表现出很大差异，面对敏感性不同的宿主时大多保持不变，这表明它们的行为依赖于内在决定因素。对穗部真菌量的进展和霉菌毒素产生率的研究没有发现与致病性差异有任何简单的关系，而通过对三种菌株蛋白质组的定性和定量表征，特别是关于早期合成的假定效应子，发现了一些线索。与小麦品种无关，这三种[病原菌名称未给出]菌株在感染过程中系统地产生相同的蛋白质组，但它们的丰度存在显著差异，这使得能够对真菌的致病性进行分类。总体而言，我们的研究结果表明，[病原菌名称未给出]致病性的差异不是基于菌株特异性分子的存在，而是基于菌株确保其充分积累的能力。蛋白质丰度的差异主要由菌株遗传学驱动，部分也受宿主品种影响，但菌株与品种的相互作用很少被检测到，这表明菌株特异性蛋白质的积累不依赖于宿主品种。所有这些数据为真菌致病性决定因素提供了新知识，并为指导进一步研究提供了丰富的候选效应蛋白库。
