Table 1_Genome-wide identification, expression, and regulatory network analysis of wheat microRNAs responsive to Bipolaris sorokiniana.xlsx

Spot blotch, caused by Bipolaris sorokiniana, is an important disease that leads to significant economic losses in wheat globally. Due to the complexity of B. sorokiniana infection, identification of wheat lines with strong resistance to spot blotch is challenging. Hence, the introduction of effective disease management strategies through the manipulation of genes involved in B. sorokiniana–wheat interaction remains essential. MicroRNAs (miRNAs) play a vital role in gene regulation and are increasingly used to predict molecular networks and genes associated with disease development or resistance. In this study, we employed small RNA sequencing to profile miRNAs in a resistant (IC566637) and a susceptible (Agra Local) wheat genotype following B. sorokiniana infection. A total of 726 miRNAs, predominantly 21 to 22 nucleotides in length, were identified. Among these, 140 are differentially expressed (DE) and associated with the modulation of 894 genes. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed these target genes as secondary metabolites, ATB-binding cassette (ABC) transporters, nucleotide-binding leucine-rich repeat (NB-LRR), mitogen-activated protein kinase (MAPK) genes, and hormones associated with plant–pathogen interaction and defense signal transduction. The regulatory network constructed from this data highlights key miRNA–target interactions likely contributing to disease resistance. Quantitative RT-PCR validation of nine selected miRNAs and their corresponding target genes further supports their potential role in modulating wheat defense responses. These findings provide a comprehensive resource for understanding miRNA-mediated regulation in the wheat–B. sorokiniana pathosystem and identified promising candidate genes for future resistance breeding and genome editing efforts.

由平脐蠕孢菌（Bipolaris sorokiniana）引发的小麦斑点病是一种在全球范围内给小麦生产造成重大经济损失的重要病害。鉴于平脐蠕孢菌的侵染过程较为复杂，筛选对斑点病具备强抗性的小麦品系颇具挑战。因此，通过调控参与平脐蠕孢菌-小麦互作过程的基因以开发高效病害管理策略，仍是当前研究的关键方向。微小RNA（microRNAs, miRNAs）在基因调控中发挥核心作用，且正逐渐被广泛用于预测与病害发生或抗病性相关的分子网络及功能基因。本研究采用小RNA测序技术，对受平脐蠕孢菌侵染后的抗病小麦基因型IC566637与感病小麦基因型Agra Local中的miRNA进行了表达谱分析。研究共鉴定得到726个miRNA，其长度主要集中于21至22个核苷酸区间。其中140个为差异表达（differentially expressed, DE）miRNA，可调控894个靶基因的表达。通过基因本体（Gene Ontology, GO）与京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes, KEGG）富集分析发现，这些靶基因主要涉及次生代谢产物、ATP结合盒（ATP-binding cassette, ABC）转运蛋白、核苷酸结合富亮氨酸重复（nucleotide-binding leucine-rich repeat, NB-LRR）、丝裂原活化蛋白激酶（mitogen-activated protein kinase, MAPK）基因，以及参与植物-病原互作与防御信号转导的激素通路。基于本研究数据构建的调控网络，揭示了可能参与小麦抗病过程的关键miRNA-靶基因互作关系。针对9个筛选得到的miRNA及其对应靶基因开展的定量逆转录PCR（quantitative reverse transcription PCR, qRT-PCR）验证实验，进一步证实了它们在调控小麦防御反应中的潜在作用。本研究结果为解析小麦-平脐蠕孢菌病害系统中miRNA介导的基因调控机制提供了全面的研究资源，同时为未来的抗病育种及基因组编辑工作筛选出了极具应用潜力的候选基因。