Characterization of the Coat Protein Gene of Cymbidium mosaic virus Isolates from India

Abstract

The variability in the coat protein (CP) gene sequence of Cymbidium mosaic virus (CymMV) that naturally infects orchids worldwide was investigated. Samples were collected from different regions of India, and the gene encoding the CP of nine isolates was specifically amplified by reverse-transcription polymerase chain reaction. The amplified product obtained was cloned, sequenced and multiple sequence alignment of deduced amino acid (aa) sequences revealed considerable homology to CymMV isolates from other countries. The nucleotide sequences and the amino acid sequences were found to be 85-100% identical and 65-100% respectively. Such high sequence conservation suggests that the CymMV CP gene is highly conserved and is a suitable candidate for the development of diagnostic procedures and to provide transgenic resistance to orchids cultivated in different geographical locations. Although recombination is not common among CymMV isolates, one isolate from Cymbidium was found to be a recombinant between a Korean and a Thai isolate of the virus. IHBT communication no: 0451.

High sequence conservation among Odotoglossum ringspot virus isolates from orchids

“…The viruses cause reduction in both yield and quality of orchid flowers. Orchid diseases caused by the two viruses have frequently occurred in orchids in Korea [4] as well as in several other countries [5][6][7][8]. ORSV and CymMV have attained worldwide distribution.…”

Significant plant virus diseases in India and a glimpse of modern disease management technology

“…Later, Sherpa et al (2006a) reported ORSV in 42 different species of orchids from Sikkim by slot-blot hybridization method. They then characterized the coat protein (CP) gene of CymMV from India and amplified the gene encoding the CP gene of nine isolates using the RT-PCR (Sherpa et al 2006b). They also cloned and sequenced the amplified product, and multiple gene sequence alignments of the deduced amino acid sequence revealed considerable homology to CymMV from other countries.…”

Genetic variability in the coat protein genes of Cymbidium mosaic virus isolates from orchids

“…These viruses cause reductions in yield and quality of orchid flowers. Orchid diseases caused by these two viruses occur frequently in Korea [4] as well as in several countries [5][6][7][8]. CymMV and ORSV have attained worldwide distribution.…”

“…CymMV is mechanically transmitted through infected sap on cutting tools and potting media. CymMV-infected orchids often show a variety of symptoms such as color-breaking in flowers, streak or stripe mosaic or necrotic spots, yellowing leaves, as well as symptomless conditions [3,[6][7][8][9]. CymMV as a member of the genus Potexvirus, has a positive-sense single-stranded RNA genome of about 6.3 kb containing 5 ORFs flanked by 5 0 and 3 0 non-coding regions plus 3 0 poly(A) tail [9,10].…”