Cloning and Sequencing of Coat Protein Geng of Malformed Leaf Strain of Papaya Ringspot Virus

The coat protein(CP)gene of an isolate of papaya malformed leaf virus(PMaLV),preserved in Plant Virology Laboratory of South China Agricultural University by Luo Xuehai,was synthesized by reverse transcription and polymerase chain reaction(RT PCR) and cloned into pGEM T and pGEM T Easy Vector System(T vector).The full length of the CP gene was sequenced,and it shown that the CP gene was 861 nucleotides(nt) in length,with 3nt deletion beginning from 66nt as compared with that of Hawaii strain(HA) and Australian strain W of papaya ringspot virus(PRSV).Compared with Ys(yellow ringspot strain)?Sm(severe mosaic strain)?G(Hainan isolate)?HA and W strains of PRSV,the CP gene sequence of PMaLV shared 96%?98%?95%?89% and 89% nucleotide sequence identity respectively.The coat protein encoded by CP gene of PMaLV consisted of 287 amino acids residues,and shared 98%?97%?97%?96% and 95% amino acid identity with those of the five strains respectively.This results of sequence analysis shown conclusively that PMaLV is a s