PDF(Pubmed)
Abstract：
Small RNAs act as fungal pathogen effectors that silence host target genes to promote infection, a virulence mechanism termed cross-kingdom RNA interference (RNAi). The essential pathogen factors of cross-kingdom small RNA production are largely unknown. We here characterized the RNA-dependent RNA polymerase (RDR)1 in the fungal plant pathogen Botrytis cinerea that is required for pathogenicity and cross-kingdom RNAi. B. cinerea bcrdr1 knockout (ko) mutants exhibited reduced pathogenicity and loss of cross-kingdom small RNAs. We developed a \"switch-on\" GFP reporter to study cross-kingdom RNAi in real-time within the living plant tissue which highlighted that bcrdr1 ko mutants were compromised in cross-kingdom RNAi. Moreover, blocking seven pathogen cross-kingdom small RNAs by expressing a short-tandem target mimic RNA in transgenic Arabidopsis thaliana led to reduced infection levels of the fungal pathogen B. cinerea and the oomycete pathogen Hyaloperonospora arabidopsidis. These results demonstrate that cross-kingdom RNAi is significant to promote host infection and making pathogen small RNAs an effective target for crop protection.
摘要：
小RNA充当真菌病原体效应子，沉默宿主靶基因以促进感染，一种称为交叉王国RNA干扰(RNAi)的毒力机制。跨王国小RNA产生的基本病原体因子在很大程度上是未知的。我们在此对真菌植物病原体灰葡萄孢中的RNA依赖性RNA聚合酶（RDR）1进行了表征，这是致病性和跨界RNAi所必需的。灰霉病菌bcrdr1敲除（ko）突变体表现出降低的致病性和跨王国小RNA的损失。我们开发了一个“打开”GFP报告子，以在活体植物组织中实时研究跨王国RNAi，这突显了bcrdr1ko突变体在跨王国RNAi中受到损害。此外，通过在转基因拟南芥中表达短串联靶模拟RNA来阻断7种病原体跨王国小RNA，从而降低了真菌病原体B.cinerea和卵菌病原体Hyaloperonosporaarabidopsidis的感染水平。这些结果表明,交叉王国RNAi对于促进宿主感染和使病原体小RNA成为作物保护的有效靶标是重要的。
