natural-products-in-plant-pest-management

Control of Virus Diseases of Plants 1677.6 ConclusionWith the precipitous withdrawal of some of the toxic protectants, it may beprofitable to explore natural plant products as alternatives, particularlyagainst virus diseases where all other methods fail. The phytoproteins ortheir smaller peptides may prove valuable as ‘lead structures’ for the developmentof synthetic compounds. It would pay us to explore this rich sourceof antivirals more thoroughly. The value of these antiviral proteins is unlimitedbecause they are quite safe, non-toxic even after repeated and prolongeduse, and substantially enhance plant growth and yield. Antiviral phytoproteinsmay be useful if they are integrated with other strategies of virus diseasemanagement.Botanical resistance inducers can be classified as ideal virus-suppressingagents, as they encompass all the characteristics of an ideal antiviral compound.Induced resistance operates through the activation of natural defencemechanisms of the host plant and induces systemic resistance to viral multiplicationin plants. The active products present in these extracts have nodirect effect on viruses; their antiviral activity is mediated by host cells inwhich they induce the antiviral state. Systemic resistance inducers obtainedfrom plants have been shown to be effective against a wide range of viruses.Plant extracts or the semi-purified proteins from these plants stimulate thehosts to produce a virus inhibitory agent, which spreads to surroundingtissues and other plant parts.ReferencesAlexander, D., Goodman, R.M., Gut-Rella,M., Glascock, C., Weymann, K., Friedrich,L., Maddox, D., Ahi-Goy, P., Lunz,T., Ward, E. and Ryals, J. (1993) Increasedtolerance of two oomycete pathogensin transgenic tobacco expressingpathogenesis-related protein 1a. Proceedingsof National Academy of Sciences USA90, 7327–7331.Aron, G.M. and Irvin, J.D. (1980) Inhibitionof herpes simplex virus multiplicationby the pokeweed antiviral protein.Antimicrobial Agents Chemotherapy 17,1032–1033.Awasthi, L.P., Chowdhury, B. and Verma,H.N. (1984) Prevention of plant virus diseaseby Boerhaavia diffusa inhibitor. IndianJournal of Tropical Plant Diseases 2, 41–44.Awasthi, L.P., Kluge, S. and Verma, H.N.(1989) Characterstics of antiviral agentsinduced by Boerhaavia diffusa glycoproteinin host plants. Indian Journal of Virology 3,156–169.Awasthi, L.P., Pathak, S.P., Gautam, N.C. andVerma, H.N. (1985) Control of virusdiseases of vegetable crops by a glycoproteinisolated from Boerhaavia diffusa. IndianJournal of PIant Pathology 3, 311–327.Awasthi, L.P. (1981) The purification andnature of an antiviral protein from Cuscutareflexa plants. Archives of Virology 70,215–223.Baranwal, V.K. and Ahmad, N. (1997) Effectof Clerodendrum aculeatum leaf extract ontomato leaf curl virus. Indian Phytopathology50, 297–299.Barbieri, L. and Stirpe, F. (1982) Ribosomeinactivating proteins from plants propertiesand possible uses. Cancer Survey 1,489–520.