Table_1_A Similar Secretome Disturbance as a Hallmark of Non-pathogenic Botrytis cinerea ATMT-Mutants?.XLSX

The gray mold fungus Botrytis cinerea is a necrotrophic pathogen able to infect hundreds of host plants, including high-value crops such as grapevine, strawberry and tomato. In order to decipher its infectious strategy, a library of 2,144 mutants was generated by random insertional mutagenesis using Agrobacterium tumefaciens-mediated transformation (ATMT). Twelve mutants exhibiting total loss of virulence toward different host plants were chosen for detailed analyses. Their molecular characterization revealed a single T-DNA insertion in different loci. Using a proteomics approach, the secretome of four of these strains was compared to that of the parental strain and a common profile of reduced lytic enzymes was recorded. Significant variations in this profile, notably deficiencies in the secretion of proteases and hemicellulases, were observed and validated by biochemical tests. They were also a hallmark of the remaining eight non-pathogenic strains, suggesting the importance of these secreted proteins in the infection process. In the twelve non-pathogenic mutants, the differentiation of infection cushions was also impaired, suggesting a link between the penetration structures and the secretion of proteins involved in the virulence of the pathogen.

灰霉菌（Botrytis cinerea）是一类死体营养型病原物，可侵染数百种寄主植物，涵盖葡萄、草莓、番茄等高价值经济作物。为解析其侵染策略，研究团队通过根癌农杆菌介导转化（Agrobacterium tumefaciens-mediated transformation, ATMT）技术开展随机插入诱变，构建了包含2144个突变体的突变体文库。研究人员筛选出12株对不同寄主植物完全丧失致病力的突变体进行深入分析，分子特征鉴定结果显示，这些突变体的基因组中均仅存在一处T-DNA插入位点，且插入位置各不相同。随后采用蛋白质组学方法，将其中4株突变体的分泌组（secretome）与亲本菌株的分泌组进行对比，发现二者的裂解酶分泌谱普遍呈现下调趋势。经生化实验验证，该分泌谱存在显著差异，具体表现为蛋白酶与半纤维素酶的分泌缺陷。这一分泌特征同样存在于其余8株非致病突变体中，提示此类分泌蛋白在病原菌侵染过程中发挥关键作用。对12株非致病突变体的进一步分析表明，其侵染垫（infection cushions）的分化过程受到阻滞，这表明病原菌的侵染结构与致病相关蛋白的分泌之间存在内在关联。