THE LONG-TERM OBJECTIVE OF THE PROJECT IS TO PRODUCE GENES OF PROVEN UTILITY FOR TRANSFER TO CROP PLANTS, THAT WILL CONFER NOVEL RESISTANCE TO PESTS AND DISEASES WITHOUT UNDESIRABLE SIDE EFFECTS. THE WORK COULD BE OF GREAT IMPORTANCE IN REDUCING THE DEPENDANCE OF AGRICULTURE ON PESTICIDES.
Ribosome inactivating proteins (RIP) and lectins are found in a wide range of plants including crops, such as wheat, barley and maize, and are present possibly as 'defence substances' against attack by pests and pathogens. Some have a potent inhibitory action on protein synthesis in animals and other organisms. The potential value of these factors for transfer into susceptible plants as 'natural' antipest mechanisms has been investigated in this programme.
2 selected RIPs (ricin and saporin) were clearly demonstrated to be extremely toxic to the growth and development of certain insect species. Concentrations down to less than 0.01% were effective. In contrast, some insects tested were completely resistant. Bioassays using plant fungal pathogens and plant nematode pests indicated that these were also resistant to RIPs probably because they fail to absorb the protein. 10 new RIPs were isolated and their properties evaluated. Other RIPs are being tested for toxicity against insects and animals. A substantial amount of protein sequence was obtained from 1 highly purified RIP. This has enabled novel methods for isolating genes to be developed. The genes encoding the 2 tested RIPs were isolated for further investigations. Genes for certain RIPs could be of great potential value for the use of agriculture as selective antiinsect factors.
IT IS PROPOSED TO EXPLORE THE USE OF CYTOTOXIC PROTEINS IN GENETIC ENGINEERING OF CROP PLANTS TO CONFER PEST AND DISEASE RESISTANCE. THE GENES ENCODING THE PROTEINS WILL BE ISOLATED AND CLONED AT DURHAM, AND TRANSFERRED TO TOBACCO AS A MODEL SYSTEM USING THE AGROBACTERIUM TI-PLASMID GENE TRANSFER TECHNOLOGY.
IN BOLOGNA, WORK WILL CONCENTRATE ON ISOLATING THESE PROTEINS AND RAISING ANTIBODIES AGAINST THEM, EXAMINING THE EFFECTS AND SPECIFICITY OF THESE PROTEINS ON IN VITRO PROTEIN SYNTHESIZING SYSTEMS, EXAMINING THEIR EFFECT ON PLANT CELLS IN TISSUE CULTURE, AND DETERMINING THE EXTENT AND BASIS OF THEIR ANTI-VIRAL ACTIVITY.
Funding SchemeCSC - Cost-sharing contracts