Plant & Animal Genomes XI Conference Plant & Animal Genomes XI ConferenceJanuary 11-15, 2003
Town & Country Convention Center
San Diego, CA
Poster: Gene Isolation
Papaya Ring Spot Virus (PRSV) causes major diseases on papaya and cucurbits in the Indian subcontinent resulting in significant yield loss. We have isolated, cloned and sequenced the coat protein gene of a South Indian isolate (UAS-BLR) of PRSV-P to characterize it at the molecular level for use in transgenic resistance. The sequence data revealed an open reading frame of 849bp encoding the putative coat protein having 282 amino acids. The DAG triplet associated with aphid transmissibility and the potential protease cleavage site Q/S, located in the N-terminus of the CP conformed to the earlier reports on PRSV coat protein. Comparative sequence analysis with 13 other CP sequences from different geographical locations revealed that most of the variability, up to 8-13% was confined to the N-terminus of CP. The CP shared about 86.6% and 92% nucleotide and amino acid sequence similarity respectively with the other Indian isolate reported,indicating the distinctness of the virus with respect to its geographical origin. The phylogenetic analysis also revealed a higher divergence of the UAS-BLR isolate with respect to its coat protein gene from the other isolates including the one from India by forming a separate and distinct group. Sequence variability may have important implications for the use of CP-genes in transgenic resistance as such forms of resistance have been observed to be highly sequence specific.