RNAi介导SMV-P3基因沉默增强大豆对花叶病毒病的抗性

RNAi-mediated SMV-P3 Silencing Increases Soybean Resistance to Soybean Mosaic Virus

大豆花叶病毒（Soybean mosaic virus,SMV）病是我国各大豆主产区最重要的病害之一,严重影响大豆产量和籽粒外观品质。培育抗病品种是防治该病害最经济有效的措施。本研究基于植物介导RNA干扰（RNA interference,RNAi）技术,将编码参与SMV运动和影响宿主域范围的P3蛋白基因RNAi片段导入栽培大豆品种,研究RNAi介导SMV-P3基因沉默对大豆抗SMV的影响。Southern杂交检测结果表明,外源RNAi片段以低拷贝的形式（1~4个）整合至大豆基因组中。对T_1~T_3代转基因大豆喷施除草剂和PCR鉴定结果表明,外源T_-DNA插入片段在转基因大豆不同代际间能够稳定遗传。对T_2和T_3代转基因大豆接种SMV鉴定结果表明,转基因大豆对我国大豆产区主要流行SMV株系SC-3较非转基因对照受体品种Williams 82和SN9的抗性水平显著提高,病情指数降低至4.37~18.51,且抗性能够稳定遗传。综上所述,RNAi介导SM-P3基因沉默能够显著提高转基因大豆对SMV的抗性水平。

Soybean mosaic virus（SMV） is one of the most important diseases in major soybean production areas and has severe effects on soybean production and seed quality in China. Breeding disease-resistant varieties is the most economical and effective strategy to prevent and control SMV. In this study, RNAi fragments of the gene encoding P3 protein, which is involved in SMV mobility and affecting host range, were introduced into soybean by plant-mediated RNA interference（RNAi） techniques to explore the influence of RNAi-mediated SMV-P3 silencing on soybean SMV resistance. Southern blot analysis revealed that exogenous RNAi fragments were integrated into the soybean genome at low copy numbers（1–4）. T1–T3 generation transgenic soybeans were sprayed with herbicide and inserted fragments were examined using PCR. The results indicated that T-DNA insertion fragments could be stably inherited between generations of transgenic soybean. Inoculation of T2 and T3 generation transgenic soybeans with SMV suggested that transgenic soybeans exhibited significantly higher resistance to the prevailing SMV strain, SC-3, in major soybean production areas than the non-transgenic control varieties Williams 82 and SN9. The disease index was reduced by 4.37–18.51. Further, the resistance could be stably inherited. In conclusion, RNAi-mediated SMV-P3 silencing can significantly increase the SMV resistance of the transgenic soybean.