Status of genetically engineered insect pest resistant crops and related biosafety concerns.

摘要

The era of modern plant biotechnology has provided eco-friendly approaches for pest management by genetic engineering of plants for pest resistance particularly insects. Transgenic plants engineered to contain genes for pest resistance were first field tested in 1988 and started being grown commercially since 1995. From 1995-2006, the commercial planting of transgenic pest resistant plants has increased rapidly. Of this a large percentage is of pest resistant crops containing the Bacillus thuringiensis (Bt) gene, conferring protection from certain insect pests. Three commercial transgenic crops viz., cotton, maize and potato have so far been introduced with Bt genes for insect control. Many other crops are also being engineered to express the Bt toxin. In India, only Bt cotton (resistant against cotton bollworm) is approved with cry1Ac; cry1Ac & cry2Ab genes. Currently, about 300 institutions in India are engaged in research on transgenics, developing crops resistant to different pests using different genes. Recently, Genetic Engineering Approval Committee, India's apex body, has approved large-scale field trials of the fruit and shoot borer resistant brinjal. Presently, genes encoding endogenous plant defensive proteins viz., proteinase inhibitors and lectins are also being explored for imparting insect resistance to crops. Bio safety issues i.e. ensuring safety to human and animal health and environment from the possible adverse effects of insect resistant crops needs to be addressed on case-to-case basis for transgenics to be truly eco-friendly.