The ascomycete fungus Magnaporthe oryzae is a hemibiotrophic pathogen that causes rice blast disease. Magnaporthe oryzae infects rice leaves, stems and panicles, and induces severe reductions in yield. Effector proteins secreted by M. oryzae in planta are thought to be involved its virulence activity. Here, using RNA‐sequencing (RNA‐Seq), we generated transcriptome data for M. oryzae isolate Ina168 during the initial stages of infection. We prepared samples from conidia (the inoculum) and from peeled epidermal cotyledon tissue of susceptible barley Hordeum vulgare ‘Nigrate’ at 12, 24, 36 and 48 hours post‐inoculation (hpi). We also generated a draft genome sequence of M. oryzae isolate Ina168 and used it as a reference for mapping the RNA‐Seq reads. Gene expression profiling across all stages of M. oryzae infection revealed 1728 putative secreted effector protein genes. We selected seven such genes that were strongly up‐regulated at 12 hpi and down‐regulated at 24 or 36 hpi and performed gene knockout analysis to determine their roles in pathogenicity. Knockout of MoSVP, encoding a small putative secreted protein with a hydrophobic surface binding protein A domain, resulted in a reduction in pathogenicity, suggesting that MoSVP is a novel virulence effector of M. oryzae.

中文翻译：

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在植物表达的稻瘟病菌基因中，RNA-Seq鉴定MoSVP为感染初期致病性所需的高表达基因。

子囊真菌稻瘟病菌是引起稻瘟病的半生营养病原体。稻瘟病菌感染稻叶，茎和穗，并导致产量严重下降。人们认为米曲霉在植物中分泌的效应蛋白与其毒力有关。在这里，我们使用RNA测序（RNA-Seq），在感染初期就产生了米曲霉分离株Ina168的转录组数据。我们在接种后第12、24、36和48小时从易感大麦大麦'Nigrate'的分生孢子（接种物）和去皮的表皮子叶组织中制备了样品。我们还产生了米曲霉的基因组序列草案分离Ina168，并用作绘制RNA‐Seq读数的参考。在米曲霉感染的所有阶段的基因表达谱分析揭示了1728个假定的分泌效应蛋白基因。我们选择了7个在12 hpi时上调而在24或36 hpi时下调的基因，并进行基因敲除分析以确定它们在致病性中的作用。MoSVP的敲除，编码带有疏水表面结合蛋白A结构域的假定的小分泌蛋白，导致致病性降低，这表明MoSVP是米曲霉的一种新型毒力效应因子。