The overall goal of the proposed project is to develop a novel way to control insect pests. The project will assess the feasibility of protecting crops from insect attacks by expressing naturally occurring insect signaling peptides in plants.
Modern agriculture faces the challenge to secure the food supply in an environmentally compatible manner. Weeds, diseases and pests are among the most serious problems threatening the production of a successful harvest. The tools at the disposal of the farmer to combat insects include adapted crop varieties and pest management programmes. Breeding for insect resistant crop varieties is often hampered by a lack of resistance alleles present in the germplasm. The use of chemical insecticides (and pesticides in general) is more and more criticized because of potential environmental problems which may accrue. Biological control with baculovirus, bacteria, fungi or parasitic wasps, represents less than 1% of the chemical insecticide sales and only finds application in specific circumstances.
Bacillus thuringiensis toxins are now widely used. However, the major threat to the Bt-plant technology, although very successful at this moment, is the potential of insect populations to develop resistance (Van Rie et al., 1995). It is now the right time to proceed with the research to find novel insecticidal toxins as alternatives for Bt-toxins when Bt-resistance would become a major problem.
In this project we propose to explore an alternative approach for generating insect tolerant crops varieties. Since 1985, insect physiologists have discovered about 100 different insect signaling peptides. We have identified a set of such peptides which we think to have the potential to become a new class of insecticides. These peptides control different physiological processes, such as inhibition of ecdysone synthesis, inhibition of juvenile hormone synthesis, stimulation of cardiac muscle activity, inhibition of gut motility, etc. The development of insects exposed to such peptides in unphysiological dosages or at unusual times is dramatically disturbed and can lead to growth inhibition and death. The question is of course whether peptides can survive in the gut environment, pass through the gut wall, enter the hemolymph and still maintain their biological activity. A few papers showing that this is indeed the case have already been published.
In this project we propose to:
1. study and select signaling insect peptides which enter the hemolymph upon oral administration,
2. design and synthesize peptide analogous for improved stability and gut transition,
3. improve the already realised expression in tomatoes of a synthetic gene coding for the insect peptide proctolin and realise the poexpression of the allatostatin gene.
4. develop and evaluate transgenic crops expressing insect peptides which are orally active.
The resulting insect tolerant crop varieties will contribute to the effort of developing an environmentally friendly and sustainable agriculture. This goal fits the CAP, promotes plant health, reduces farmers inputs and in general should be more acceptable to the consumer than some current practices.
Funding SchemeCSC - Cost-sharing contracts
WC1E 7HX London
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80055 Portici Napoli