THE DEVELOPMENT OF PEST RESISTANT TRANSGENIC PLANTS

The status of the development of pest-resistant transgenic plants was reviewed with primary focus on insect resistance. Such plants are genetically altered by recombinant DNA to exhibit resistance to one or more pest species. Bacterial plasmids such as found in Agrobacterium tumefaciens have proven to be effective vectors for introducing desired genes into DNA of selected host plant species. Genes have been success-fully transferred by both protoplast and intact cell wall transformation. Transfer techniques include: (1) Agrobacterium tumefaciens - mediated transfer of genes, (2) micro-injection of genes into cell nuclei, (3) protoplast-dependent direct transfer of genes, and (4) particle gun techniques (biolistics) whereby tungsten or gold particles coated with DNA are propelled under high velocity into intact plant cells. The gene for insect control in Bacillus thuringiensis has been isolated and success-fully inserted into the DNA of plant cells of cotton and potatoes for control of certain Lepidopteran and Coleopteran insects. Similar investigations are being conducted on other plants including tomato, maize, and tobacco. Two concerns regarding development of insect-resistant transgenic plants are the potential for insects to develop resistance and the receptivity of the general public to use such plants for human consumption