Effects Of Coat Protein On Infection And Virulence Of Tobacco Vein Banding Mosaic Virus

Tobacco vein banding mosaic virus (TVBMV) is one species of the genus Potyvirus. The losses caused by TVBMV had been increasing during the recent years. The coat protein (CP) plays an important role in the virus infection cycles, such as aphid transmission, replication, assembly, movement and systemic infection. In the study, twelve mutants of TVBMV CP was obtained via site-directed mutagenesis and analyzed for their activities on virus pathogenicity via agroinfiltration.Compared with that of wild type CP, treatment with substitution mutation of Ser92to Ala92resulted in no obvious change in symptom and gree fluorescence, treatment with substitution of Ser92to Asp92or His92resulted in reduced symptoms and gree fluorescence; substitution of Trp122to Lys122, Arg192to Cys192, Lys225to Cys225or Ala225resulted in the green fluorescence appeared only in the inoculted lesves; substitution of Trp122to Ala122or Glu122, Arg192to Ala192or Glu192and Lys225to Glu225resulted in no symptoms or green fluorescence on the inoculted leaves or systemic lesves.The database Pole Bio-Informatique Lyonnais was used to predict the secondary structure of12mutant proteins, the prediction results indicated that the secondary structure of the mutants had changed. These results indicated that amino acids Ser92, Trp122, Arg192and Lys225play important roles in the pathogenesis of TVBMV.