Effect of a silencing suppressor gene towards the expression of VP2 protein of highly virulent infectious bursal disease virus in tobacco

Abstract

Gene silencing has been recognized as an important factor, which influence the expression of heterologous protein delivered via plant-viral based system. The application of suppressor genes that act against gene silencing mechanisms demonstrated improvement in the expression level of heterologous protein in plants. The aim of the present study was to evaluate the ability of a silencing suppressor gene to enhance the expression of VP2 protein of highly virulent infectious bursal disease virus in Nicotiana benthamiana plants using a plant viral-based expression system derived from potato virus X. In the present study, a silencing suppressor gene of P19 encoded by tomato bushy stunt virus was employed as a suppressor for gene silencing mechanism by co-infecting N. benthamiana plants with the P19 gene via agroinfiltration strategy followed by mechanical inoculation of potato virus X viral transcripts containing the cloned VP2 gene. Western blot analyses revealed that the expressed VP2 protein can be detected by 7 days post-infection in the presence of P19 gene as compared with plants without P19 gene that can only be detected at 10 days post-infection. However, there was no significant enhancement in the yield of expressed VP2 protein in the presence of P19 gene. The present findings demonstrated the employment of P19 gene and improved the expression of hvIBDV VP2 protein in N. benthamiana plants.

Keywords

• infectious bursal disease virus
• VP2
• protein expression
• silencing suppressor gene
• P19 gene
• Nicotiana benthamiana