Gan Pamela, Hiroyama Ryoko, Tsushima Ayako, Masuda Sachiko, Shibata Arisa, Ueno Akiko, Kumakura Naoyoshi, Narusaka Mari, Hoat Trinh Xuan, Narusaka Yoshihiro, Takano Yoshitaka, Shirasu Ken
RIKEN Center for Sustainable Resource Sciences, Yokohama, Kanagawa, Japan.
Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, Japan.
Environ Microbiol. 2021 Oct;23(10):6004-6018. doi: 10.1111/1462-2920.15490. Epub 2021 Apr 12.
Members of the Colletotrichum gloeosporioides species complex are causal agents of anthracnose in many commercially important plants. Closely related strains have different levels of pathogenicity on hosts despite their close phylogenetic relationship. To gain insight into the genetics underlying these differences, we generated and annotated whole-genome assemblies of multiple isolates of C. fructicola (Cf) and C. siamense (Cs), as well as three previously unsequenced species, C. aenigma (Ca), C. tropicale and C. viniferum with different pathogenicity on strawberry. Based on comparative genomics, we identified accessory regions with a high degree of conservation in strawberry-pathogenic Cf, Cs and Ca strains. These regions encode homologs of pathogenicity-related genes known as effectors, organized in syntenic gene clusters, with copy number variations in different strains of Cf, Cs and Ca. Analysis of highly contiguous assemblies of Cf, Cs and Ca revealed the association of related accessory effector gene clusters with telomeres and repeat-rich chromosomes and provided evidence of exchange between these two genomic compartments. In addition, expression analysis indicated that orthologues in syntenic gene clusters showed a tendency for correlated gene expression during infection. These data provide insight into mechanisms by which Colletotrichum genomes evolve, acquire and organize effectors.
胶孢炭疽菌复合体的成员是许多重要商业植物炭疽病的病原体。尽管亲缘关系密切，但相关菌株对宿主的致病性水平却有所不同。为深入了解这些差异背后的遗传学机制，我们生成并注释了多种果生炭疽菌（Cf）、暹罗炭疽菌（Cs）分离株以及另外三个之前未测序的物种——对草莓具有不同致病性的神秘炭疽菌（Ca）、热带炭疽菌和葡萄炭疽菌的全基因组组装序列。基于比较基因组学，我们在对草莓致病的Cf、Cs和Ca菌株中鉴定出了具有高度保守性的辅助区域。这些区域编码被称为效应子的致病性相关基因的同源物，它们以共线性基因簇的形式组织在一起，在Cf、Cs和Ca的不同菌株中存在拷贝数变异。对Cf、Cs和Ca高度连续的组装序列分析揭示了相关辅助效应子基因簇与端粒和富含重复序列的染色体之间的关联，并提供了这两个基因组区域之间发生交换的证据。此外，表达分析表明，共线性基因簇中的直系同源基因在感染过程中呈现出相关基因表达的趋势。这些数据为炭疽菌基因组进化、获取和组织效应子的机制提供了深入见解。
