Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai-625 021, India.
Abstracts of the papers presented at the XVIII National Conference of Indian Virological Society at Post Graduate Institute of Medical Education and Research, Chandigarh, India, December 11–13, 2008.
Bhendi yellow vein mosaic virus (BYVMV) is a member of the Begomovirus genus of the family Geminiviridae, infecting bhendi (okra, Abelmoschus esculentus) plants by whitefly transmission. BYVMV encodes for C2, C4 and bC1 which are suppressors of Post Transcriptional Gene Silencing (PTGS). Suppressor of Gene Silencing 3 (SGS3) is a plant protein that is involved in juvenile development, PTGS and natural virus resistance. The AV2 protein of TYLCV has been shown to suppress PTGS through its interaction with SGS3. The aim of the present study is to study whether the BYVMV proteins C2, C4 and bC1 interact with SGS3. Yeast two hybrid system was used to study the interaction between the host protein SlSGS3 and the viral proteins C2, C4 andbC1. The strength of the interaction was elucidated by means of qualitative and quantitative assay for b galactosidase activity and Leucine prototrophy. The BYVMV protein C2 was found to interact strongly, whereas the protein bC1 interacts weakly with SlSGS3. The interaction of C4 is being investigated. From the results obtained it can be proposed that the interaction between BYVMV encoded suppressors of gene silencing C2 and bC1 and SGS3 brings about the suppression of PTGS. Further studies like Bimolecular Fluorescence Complementation and Pull down assay will be carried out to confirm the results. This will help us in gaining insights into how the virus interacts with the host in bringing about the suppression of gene silencing.
