立枯丝核菌Rhi-milR9829-5p与水稻和大豆互作的分子机理

Molecular Mechanism of Interaction of Rhizoctonia solani RhimiR9829-5p with Rice and Soybean

立枯丝核菌可侵染水稻、大豆等260多种植物,是作物生产中的主要真菌性病害致病菌之一。microRNA(miRNA)是一类由20~25个核苷酸组成的非编码RNA分子,可以通过降解mRNA或抑制mRNA的翻译从而在转录或翻译水平上负调控靶基因的表达。已有研究表明,miRNA参与了真菌与植物互作等多种生物学过程。在前期研究中,课题组鉴定到一个能够负调控玉米抗病性的立枯丝核菌Rhi-milR9829-5p,为了进一步研究其在不同作物中的致病功能和机理,本研究获得了Rhi-milR9829-5p成熟体过量表达的水稻转基因植株,对阳性T1代植株接种立枯丝核菌后发现,Rhi-milR9829-5p过量表达的水稻植株对纹枯病的抗性显著降低。利用生物信息学方法分别预测了Rhi-milR9829-5p在水稻和大豆中的下游靶基因并进行功能注释分析,结果表明Rhi-milR9829-5p通过多种生物学途径调控水稻和大豆的抗病性,且在水稻和大豆中存在明显不同。研究结果初步揭示了立枯丝核菌Rhi-milR9829-5p调控水稻和大豆抗病性的分子机理,进一步验证了miRNA的跨物种调控功能,为作物抗病分子育种提供了基因资源。

The fungus Rhizoctonia solani can infect over 260 plant species including rice and soybean,making it one of the major fungal pathogens in crop production.microRNAs(miRNAs)are a class of non-coding RNA molecules composed of 20-25 nucleotides,which can regulate the expression of target genes at the transcriptional or translational level by degrading or inhibiting mRNA.Previous studies have shown that miRNAs are involved in various biological processes such as fungalplant interactions.In earlier research,a miRNA,Rhi-milR9829-5p,was identified by the research team to negatively regulate maize resistance to diseases.To further study its pathogenic functions and mechanisms in different crops,this study obtained transgenic rice plants overexpressing Rhi-milR9829-5p mature bodies.Upon inoculation with Rhizoctonia solani,it was found that the transgenic rice plants with overexpressed Rhi-milR9829-5p showed significantly reduced resistance to sheath blight.Bioinformatics methods were used to predict downstream target genes of Rhi-milR9829-5p in rice and soybean and to conduct functional annotation analysis.The results indicated that Rhi-milR9829-5p regulates the resistance of rice and soybean to diseases through multiple biological pathways,with distinct mechanisms observed between the two crops.The research results provide preliminary insights into the molecular mechanisms by which Rhi-milR9829-5p from Rhizoctonia solani regulates disease resistance in rice and soybean,further confirming the cross-species regulatory function of miRNAs and offering genetic resources for molecular breeding of disease-resistant crops.