Caseys Céline, Kliebenstein Daniel J
Department of Plant Sciences, University of California, Davis, CA 95616, USA.
Genetics. 2025 Jul 9;230(3). doi: 10.1093/genetics/iyaf079.
Diverse qualitative and quantitative genetic architectures can successfully enable fungal virulence and host range. To model the quantitative genetic architecture of a generalist pathogen with an extensive host range, we conducted a genome-wide association study (GWAS) of the lesion area of Botrytis cinerea across 8 hosts. This revealed that it was possible to partition the virulence, as defined by the lesion area, common across all hosts from host-specific virulence. All traits showed that a large proportion of the Botrytis genome likely contributes to fungal lesion development on leaves with small effect sizes. The candidate genes are evenly spread across the core chromosomes with no indication of bipartite genomic architecture. The GWAS-identified polymorphisms and genes show that B. cinerea relies on genetic variants across hundreds of genes for growing on diverse hosts, with most genes influencing relatively few hosts. When pathogen genes were associated with multiple hosts, they were associated with unrelated rather than related host species. Comparative genomics further suggested that the GWAS-identified genes are largely syntenic with other specialist Botrytis species and not unique to B. cinerea. Overall, as shown in Arabidopsis thaliana, B. cinerea's generalist behavior is derived from the sum of the genome-wide genetic variation acting within gene networks that differentially coordinate the interaction with diverse hosts.
多种定性和定量的遗传结构能够成功地促成真菌的毒力和宿主范围。为了模拟具有广泛宿主范围的泛化病原体的定量遗传结构，我们对灰葡萄孢菌在8种宿主上的病斑面积进行了全基因组关联研究（GWAS）。这表明，有可能将所有宿主共有的、由病斑面积定义的毒力与宿主特异性毒力区分开来。所有性状均表明，灰葡萄孢菌基因组的很大一部分可能对叶片上真菌病斑的发展有贡献，但其效应大小较小。候选基因均匀分布在核心染色体上，没有二分基因组结构的迹象。GWAS鉴定出的多态性和基因表明，灰葡萄孢菌在不同宿主上生长依赖于数百个基因的遗传变异，大多数基因影响的宿主相对较少。当病原体基因与多个宿主相关联时，它们与不相关而非相关的宿主物种相关联。比较基因组学进一步表明，GWAS鉴定出的基因在很大程度上与其他专化型葡萄孢菌物种是共线的，并非灰葡萄孢菌所特有。总体而言，如拟南芥所示，灰葡萄孢菌的泛化行为源自基因网络内全基因组遗传变异的总和，这些基因网络以不同方式协调与不同宿主的相互作用。
