Survey on Distributions and Infectious Status of Three Main Kinds of Papaya Virus by ID-ELISA in Hainan
The CP genes were amplified from PRSV, PLDMV and Pa MV sequences by PCR, which were kept in our laboratory. Then the CP genes were connected to prokaryotic expression vector of p ET-28 a, after identification by enzyme digestion and sequencing, the three recombinant plasmids of p ET28-PRSV-CP, p ET28-PLDMV-CP and p ET28-Pa MV-CP were transformed into the expressing bacteria BL21( DE3). The CP genes were expressed efficiently with IPTG inducing by SDS-PAGE analysis. PRSV CP and PLDMV CP existed in the form of inclusion body, while Pa MV CP expressed in the soluble form. The expressed proteins were purified with Ni2+-NTA agarose affinity chromatography and were used as antigens to immunize the rabbits for antiserum preparation. Western blot analysis confirmed that the antiserum only reacted with the corresponding expressed induced protein. 283 of unhealthy papaya leaves collected on the whole Hainan were tested by ID-ELISA. This study would preliminarily establish the distribution of papaya virus in Hainan, and provid scientific basis and a effective method for the prevention of papaya virus.