Cercospora sojina is a fungal pathogen that causes frogeye leaf spot in soybean-producing regions, leading to severe yield losses worldwide. It exhibits variations in virulence due to race differentiation between strains. However, the candidate virulence-related genes are unknown because the infection process is slow, making it difficult to collect transcriptome samples. In this study, virulence-related differentially expressed genes (DEGs) were obtained from the highly virulent Race 15 strain and mildly virulent Race1 strain under nitrogen starvation stress, which mimics the physiology of the pathogen during infection. Weighted gene co-expression network analysis (WGCNA) was then used to find co-expressed gene modules and assess the relationship between gene networks and phenotypes. Upon comparison of the transcriptomic differences in virulence between the strains, a total of 378 and 124 DEGs were upregulated, while 294 and 220 were downregulated in Race 1 and Race 15, respectively. Annotation of these DEGs revealed that many were associated with virulence differences, including scytalone dehydratase, 1,3,8-trihydroxynaphthalene reductase, and β-1,3-glucanase. In addition, two modules highly correlated with the highly virulent strain Race 15 and 36 virulence-related DEGs were found to contain mostly β-1,4-glucanase, β-1,4-xylanas, and cellobiose dehydrogenase. These important nitrogen starvation-responsive DEGs are frequently involved in the synthesis of melanin, polyphosphate storage in the vacuole, lignocellulose degradation, and cellulose degradation during fungal development and differentiation. Transcriptome analysis indicated unique gene expression patterns, providing further insight into pathogenesis.

中文翻译：

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两种大豆尾孢菌株的比较转录组分析揭示了氮饥饿胁迫下毒力的差异。


大豆尾孢 (Cercospora sojina) 是一种真菌病原体，会在大豆产区引起蛙眼叶斑病，导致全球严重产量损失。由于菌株之间的种族差异，它表现出毒力的变化。然而，由于感染过程缓慢，候选毒力相关基因未知，因此很难收集转录组样本。在这项研究中，从高毒力Race 15菌株和中度毒力Race1菌株在氮饥饿胁迫下获得了毒力相关的差异表达基因（DEG），模拟了病原体感染过程中的生理学。然后使用加权基因共表达网络分析（WGCNA）来寻找共表达的基因模块并评估基因网络和表型之间的关系。通过比较菌株之间毒力的转录组差异，在种族1和种族15中，总共有378个和124个DEG上调，而294个和220个DEG分别下调。这些 DEG 的注释显示，许多 DEG 与毒力差异相关，包括 scytalone 脱水酶、1,3,8-三羟基萘还原酶和 β-1,3-葡聚糖酶。此外，与高毒力菌株Race 15和36毒力相关的DEG高度相关的两个模块被发现主要含有β-1,4-葡聚糖酶、β-1,4-木聚糖和纤维二糖脱氢酶。这些重要的氮饥饿响应性 DEG 经常参与黑色素的合成、液泡中多磷酸盐的储存、木质纤维素的降解以及真菌发育和分化过程中的纤维素降解。转录组分析表明了独特的基因表达模式，提供了对发病机制的进一步了解。