Study On Genome Of Segment 5 Of Rice Black Stripe Dwarf Virus

A full-length cDNA of genomic segment 5(S5) of a Rice black-streaked dwarfvirus (RBSDV-Zj) isolated from rice in Zhejiang Province was cloned and the genomesegment contained 3164 nts and was predicted to encode two proteins of 107.1kDaand 26.5kDa. RBSDV-Zj S5 possessed the conserved terminal nucleotide sequencesof (+)5′-AAGTTTTTTTCACTC---GAGTGAATACAGCTAATGTC-3′and a 7 ntsperfect inverted repeat immediately adjacent to the terminal conserved aequence. FASTAanalysis showed that the nucleotides of RBSDV-Zj S5 was 93.58%,49% and 65.60%identical to the those of RBSDV-Hbm (an isolate from maize) S5,Fiji disease virus(FDV) S5 and Mal de Rio Cuarto virus(MRCV)S5 respectively.The protein p5A and p5B encoded by RBSDV-Zj S5 were expressed in E.coliusing expression vector and purified. Antisera to p5A and p5B were prepared. Westernblot analysis exhibited that p5A in the total proteins was detected both extracted fromRBSDV-infeeted rice leaves and purified RBSDV virions, while p5B was onlydetected in the total proteins extracted from RBSDV-infeeted rice leaves. Theseresults suggested p5A encoded a structural protein, while p5B encoded a nonstructuralprotein.Plant expression vector pRRS5B, which contained the RBSDV genome segmentS5B, was constructed, then the target gene was transferred into a Japonica ricecultivar Xiushui 04 by Agrobacterium mediated transformation. Using PCR,Southernblotting and Western blot analysis results showed that the target gene was successfullytranslated in the transgenic plants.