Division of Biotechnology, Indian Institute of Horticultural Research, Hessaraghatta, Bangalore-560089.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
Citrus tristeza virus (CTV), a member of the genus Closterovirus of the closteroviridae, a family of positive sense RNA viruses transmitted largely by the aphid (Toxoptera citricidis), is very important virus causing losses up to 100% by destroying the whole plant of most species of citrus throughout the world. Generating transgenic citrus by antibody expression for resistance to CTV appears to be one of the most promising control strategies. The outstanding performance of a recombinant single chain antibody in its ability to bind to any isolate of CTV suggests that this particular construct may be the best candidate to be expressed in plants to confer resistance to the virus. The single chain scFv antibody gene was moved into a plant expression vector and the construct was electroporated into meristematic tissues of tomato seedlings. A total of 360 T1 tomato plants were raised and 138 were screened for the presence of transgene by PCR with primers flanking the cassette. Forty-two plants were positive for the presence of the gene. PCR products from 21 plants were tested by dot blot and 17 were found to hybridize to the probe consisting of the scFv fragment. The expression of the antibody protein was studied by ELISA in 12 confirmed transgenic plants and 6 plants showed very high levels of expression. This is the first report of expression studies of a plantibody to CTV.
