Biotrophic basidiomycete plant pathogens cause billions of dollars in losses to cereal crops annually. The model for this group of fungi is the corn smut pathogen Ustilago maydis. Annotation of its genome identified antisense RNAs (asRNAs) complementary to over half of the coded mRNAs, some of which are present at high levels in teliospores but detected at very low levels or not at all in other cell types, suggesting they have a function in the teliospore or during teliospore formation. Expression of three such asRNAs (as-UMAG_02150, ncRNA1, and as-UMAG_02151) is controlled by two adjacent genomic regions. Deletion of these regions increased transcript levels of all three asRNAs and attenuated pathogenesis. This study investigated the reason for this marked reduction in pathogenesis by: (1) using deletion analyses to assess the involvement of genes, complementary to the asRNAs, in pathogenesis; (2) determining that one of the linked genes encodes a putative xylitol dehydrogenase; and (3) identifying and functionally characterizing asRNAs that could influence expression of protein-coding genes. The results presented suggest that the influence of the asRNAs on pathogenesis occurs through their action at unlinked loci.

中文翻译：

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通过转录本和基因表征，探索反义RNA与乌斯季亚戈病的发病机制之间的联系。

营养型担子菌植物病原体每年给谷物作物造成数十亿美元的损失。这种真菌的模型是玉米黑穗病病原菌Ustilago maydis。其基因组注释显示，与编码的mRNA的一半以上互补的反义RNA（asRNA），其中一些以高水平存在于孢子中，但在其他细胞类型中却以非常低的水平或根本没有被检测到，表明它们在以下细胞中具有功能孢子或在孢子形成期间。三种这样的RNA（as-UMAG_02150，ncRNA1和as-UMAG_02151）的表达受两个相邻的基因组区域控制。这些区域的删除增加了所有三种asRNA的转录水平，并减弱了发病机理。这项研究通过以下方法调查了发病率显着降低的原因：（1）使用缺失分析来评估与asRNA互补的基因在发病中的参与；（2）确定所连接的基因之一编码推测的木糖醇脱氢酶；（3）鉴定和功能表征可能影响蛋白质编码基因表达的asRNA。提出的结果表明，asRNA对发病机理的影响是通过其对未连锁基因座的作用而发生的。