RXLR effector reservoir in two Phytophthora species is dominated by a single rapidly evolving superfamily with more than 700 members
RXLR effector reservoir in two Phytophthora species is dominated by a single rapidly evolving superfamily with more than 700 members
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DOI：
10.1073/pnas.0709303105
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发表时间：
2008-03-25
影响因子：
11.1
通讯作者：
Tyler, Brett M.
中科院分区：
文献类型：
--
作者：
Jiang, Rays H. Y.;Tripathy, Sucheta;Tyler, Brett M.
病原体分泌促进其宿主感染的效应分子。在植物病原性疫霉属物种中鉴定的许多效应子具有将这些效应子靶向到宿主细胞中所需的N-末端基序（RXLR-dEER）。在这里，我们在大豆疫霉和分枝曲霉的每个基因组中生物信息学地鉴定了>370个候选效应基因。一个单一的超家族，称为无毒同源基因（Avh），占大多数的效应。Avh蛋白显示出广泛的序列差异，但都是相关的，并且可能通过快速复制和差异从共同的祖先进化而来。超过一半的Avh蛋白含有保守的C-末端基序（称为W，Y和L），这些基序通常排列为可以重复多达8次的模块。Avh基因属于基因组中进化最快的部分，并且它们几乎总是位于同线性断点。该超家族包括所有实验鉴定的卵菌效应基因和无毒基因，其快速进化的步伐与Avh蛋白在与植物宿主相互作用中的作用是一致的。
Pathogens secrete effector molecules that facilitate the infection of their hosts. A number of effectors identified in plant pathogenic Phytophthora species possess N-terminal motifs (RXLR-dEER) required for targeting these effectors into host cells. Here, we bioinformatically identify >370 candidate effector genes in each of the genomes of P. sojae and A ramorum. A single superfamily, termed avirulence homolog (Avh) genes, accounts for most of the effectors. The Avh proteins show extensive sequence divergence but are all related and likely evolved from a common ancestor by rapid duplication and divergence. More than half of the Avh proteins contain conserved C-terminal motifs (termed W, Y, and L) that are usually arranged as a module that can be repeated up to eight times. The Avh genes belong to the most rapidly evolving part of the genome, and they are nearly always located at synteny breakpoints. The superfamily includes all experimentally identified oomycete effector and avirulence genes, and its rapid pace of evolution is consistent with a role for Avh proteins in interaction with plant hosts.