Peptide-Based Biopesticides

In this presentation we describe the great potential of peptides as biopesticides. Currently Europe is greatly encouraging research in sustainable pest-management. Finding eco-friendly, effective alternatives to synthetic pesticides is of paramount importance, especially against the so-called priority pests of fruits and vegetables. For some of these pests, such as botrytis cinerea and peronospora viticola, no effective bio-alternatives to small organic molecules are available so far. Fungi belonging to the genus Trichoderma are distributed worldwide and have been used successfully in field trials against many crop pathogens. They produce peptaibols, a peculiar family of peptides, as part of their defense system against other microorganisms. Such secondary metabolites are known for their plantprotection properties: they (i) possess antimicrobial activity, (ii) act as stimulants of plant defences and growth (iii) elicit plant production of volatiles to attract natural enemies of herbivorous insects. By means of a versatile SPPS strategy, we produced several analogs of such naturally occurring peptides. With such compounds, we can circumvent both the health hazards and the unreliable effectiveness in open field connected with the use of antagonistic microorganisms as biological control agents, while keeping the biomolecules responsible for their beneficial effects. Our peptides have been tested (alone or in combination) both in vitro and in vivo against a variety of priority pests, such as the fungi Botrytis cinerea and Penicillum italicum, and the bacterium Pectobacterium carotovorum. We identified several peptaibol analogs with a broad-spectrum activity as biopesticides, able to completely inhibit the growth of B. cinerea and many other pathogens for over a week at low micromolar concentrations.