Plant Molecular Virology, National Botanical Research Institute, Lucknow-226001.
Abstracts of Research Papers Presented during the National Symposium of Indian Virological Society at Unit of Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi-110 012, October 14–1.
DNA β molecules are symptom modulating, single stranded DNA satellites associated with monopartite begomoviruses family Geminiviridae. The β DNA molecules are ∼1350 nt in length and affect the replication of their helper begomoviruses and alter the symptoms induced in some host plants. Such molecules had been shown to be associated with Ageratum yellow vein virus (AYVV) from Singapore and Cotton leaf curl Multan virus (CLCuMV) from Pakistan. Recently 26 additional DNA β molecules associated with diverse plant species obtained from different geographical locations were cloned and sequenced by Briddon and his coworkers in 2003. Two major groups of DNA β satellites were resolved by phylogenetic analyses, one group originated from hosts within the Malvaceae and second from a more diverse group of plants within the Solanaceae and Compositae.
We attempted PCR amplification using three begomovirus specific primers designed by Rojas et al. (1994), Deng et al. (1998) and Hallan et al. (1998) and the total DNA isolated from naturally infected Hibiscus and Croton plant species showing yellow vein net symptoms. Using these primers we could get amplifications of ∼1.2 Kb, 1.0 Kb and 550 bp which showed positive signal of hybridization with a probe prepared from cloned DNA-A of TLCV. These results suggested the infection of begomovirus.
To detect the association of β DNA with the virus, a pair of primers specific to β DNA (Jose and Usha, 2003) were used. We could successfully amplify such molecules of ∼ 1.3 Kb from Hibiscus and croton plant species by PCR using the primers capable of amplifying the β DNA. The associations of β DNA with yellow vein net of Hibiscus and croton are the new reports from India.
