体外施用小分子RNA抑制稻瘟病菌分生孢子发育及致病性的作用效果

[Objective] This article aims to analyze the inhibitory effect of small molecules of RNA targeting cytochrome b (Cytb) in vitro on the pathogenicity of Magnaporthe oryzae. [Methods] Magnaporthe oryzae was incubated with double-stranded small molecule RNA (ds - sRNAMoCytb - 21). By measuring the spore germination efficiency and morphology, it was determined that the small molecule RNA had an inhibitory effect on the spore germination and appressorium formation of Magnaporthe oryzae. In the cases of applying solvent (control group) or dsRNAMoCytb - 500 (treatment group) respectively, the Magnaporthe oryzae strain Guy11 was used to infect rice 'Nipponbare' to clarify whether the application of small molecule RNA in vitro could reduce the pathogenic ability of Magnaporthe oryzae. [Results] Compared with the control, the spore germination rate and appressorium formation rate of Magnaporthe oryzae incubated with small molecule RNA were significantly reduced. 2'-O-methyl modification (OMe) and thiomethoxy modification (SOMe) could prolong the inhibitory effect of small molecule RNA. The lesion area of rice sprayed with a mixture of Guy11 and dsCytb was significantly reduced compared with that of the control group. [Conclusion] The application of small molecule RNA specifically targeting Cytb of Magnaporthe oryzae in vitro can inhibit the pathogenicity of Magnaporthe oryzae and has the potential and value to be developed into a highly efficient, green and environmentally friendly RNAi agent.

[目的]本文旨在分析体外施加靶向细胞色素b（Cytb）的小分子RNA对稻瘟病菌致病性的抑制作用。[方法]将稻瘟病菌与双链小分子RNA（ds-sRNAMoCytb-21）共同孵育，通过测定孢子萌发效率和形态，确定小分子RNA对稻瘟病菌孢子萌发和附着胞形成有抑制作用。在分别施加溶剂（对照组）或dsRNAMoCytb-500（处理组）的情况下，使用稻瘟病菌菌株Guy11侵染水稻‘日本晴’，明确体外施加小分子RNA是否可以降低稻瘟病菌的致病能力。[结果]与对照相比，与小分子RNA共同孵育的稻瘟病菌孢子萌发率和附着胞形成率显著降低。2'-O-甲基修饰（OMe）和硫代甲氧基修饰（SOMe）能够延长小分子RNA的抑制效果。用Guy11和dsCytb混合喷施的水稻病斑面积较对照组显著降低。[结论]体外施加特异性靶向稻瘟病菌Cytb的小分子RNA能够抑制稻瘟病菌的致病性，具有开发成为高效绿色环保RNAi药剂的潜力和价值。