Studies On The Agrobacterium Tumefaciens-mediated Transformation Of RNAi CP Gene In Soybean(Glycine Max (L.)Merr.)

Soybean mosaic virus disease, caused by Soybean mosaic virus (SMV), is one of the destructive disease in soybean growing areas around the world. Soybean mosaic virus, classified as the genus potyvirus in the family potyviridae, was transmitted by infected seeds, aphids,and mechanical inoculation, not only does it cause soybean plants dwarf, leaves of shrinkage, mosaic, dieback symptoms, but also to make the soybean seed mottled, the soybean mosaic virus disease reduce the yield and the quality of appearance, it can reduce soybean yield by10%to30%in general and outbreaks in severe, SMV cause huge economic losses to soybean production. Germplasm exchanges and continual appearances of new virulent SMV strains have caused significant challenges to security of soybean production worldwide. Use of soybean cultivars with resistance to SMV is a very effective way of controlling the SMV disease.RNA interference (RNAi)is a phenomenon of homologous mRNA digestion mediated by double-stranded RNA(dsRNA), which is a natural defense system against virus in plants. RNAi is now widely used as a useful tool for discovering or validating gene functions, and as a quick way for engineering plants with improved agronomic traits. RNAi technology is an efficient means of gene silencing, it can be effectively used in soybean antiviral molecules breeding, create excellent soybean germplasm resources.In this study, we used the RNAi CP gene as an expression vector, the bar gene as a selective marker, the soybean were transformed via the soybean cotyledonary-node Agrobacterium-mediated transformation system, eventually,22putative transgenic soybean plants had been got, and18positive transgenic soybean were identified by the analysis of leave herbicide painting, PCR and bar quick dip stick. The genetic analysis of RNAi CP transgenic lines in the T1generation showed that the imported genes is heritable, and their genetic laws accord Mendel’s law. The Southern blot tests showed the imported interference fragment is one copy in soybean genomic DNA. The RNAi CP transgenic soybean plants showed the resistance to soybean mosaic virus after soybean mosaic virus friction inoculation. After3weeks of inoculation soybean mosaic virus, the analysis of DAS-ELISA showed the percentage of SMV detection was100in non-transgenic plants, however, in RNAi CP transgenic plants, the percentage of SMV detection was only7.69. RNAi CP transgenic soybean material obtained in this study can be used as SMV resistant germplasm resources, to accelerate soybean antiviral breeding process, to effectively prevent and control the occurrence of soybean diseases.