natural-products-in-plant-pest-management

Control of Virus Diseases of Plants 16316–20 kDa as determined by gel-filtration chromatography (Verma et al.,1979). The protein has a PI of around 9 and has a molecular weight of 30 kDa(Srivastava, 1995). The RIP was found to be extremely thermostable (Vermaand Awasthi, 1979). Following treatment with the systemic RIP, the host producesa VIA. The VIA shows characteristics of a protein and reduces infectivityof the viruses both in vitro and in vivo (Verma and Awasthi, 1980). Upongel filteration on Sephadex G-25, two active fractions exhibiting proteincharacteristics were recovered (Verma and Awasthi, 1980).The protein occurring in B. diffusa functions as a signal molecule and is ofgreat interest as it has a role in stimulating the defence system of plantsagainst viruses (Singh, 2006; Verma et al., 2006). The VIA is present in bothtreated and untreated leaves (Verma and Awasthi, 1980). Micropropagationof B. diffusa has been carried out for producing the systemic RIP for viraldisease management (Gupta, 1999; Gupta et al., 2004).Susceptible healthy hosts upon treatment with C. aculeatum extractdevelop complete resistance within 4–6 h. The SIR is reversed by the simultaneousapplication of AMD (Verma et al., 1984). Treatment with SRI from C.aculeatum leaves, triggers accumulation of a new defensive VIA in treatedand non-treated leaves of healthy host plants (Verma et al., 1984; Verma et al.,1996, 1999; Srivastava 1999). The SRI in crude sap is resistant to denaturationby organic solvents and extremely thermostable (Verma et al., 1984). Theresistance-inducing activity of C. aculeatum SRI (CA-SRI) is not affected byexogenous application of proteases (Verma et al., 1996). Leaf extract of C. aculeatumis most effective for controlling virus diseases in crop plants (Vermaet al., 1995a; Srivastava 1999; Srivastava et al., 2004). Leaf extract, whensprayed on susceptible host plants, prevents infection of mechanically andwhite fly transmitted viruses in several hosts, e.g. tomato yellow mosaicvirus, tobacco mosaic virus, sunnhemp rosette virus and tobacco leaf curlvirus (Verma et al., 1984; Verma et al., 1995a) (Table 7.2).Table 7.2. Plants containing virus inhibitory activity.Name Family ReferenceAmaranthus albus Amaranthaceae Smookler, 1971Alternanthera brasiliana Amaranthaceae Noronha et al., 1983Acacia arabicaLeguminosaeGupta and Raychauduri, 1971a(Fabaceae)Acer insulera Aceraceae Yoshi et al., 1954Agava americana Agavaceae Simon, 1963Ailanthes excelsa Simaroubaceae Patel and Patel, 1979Alternanthere fi coidea Amaranthaceae Noronha et al., 1983Amaranthus caudatus Amaranthaceae Smooker, 1971Argemone mexicana Papaveraceae Patel and Patel, 1979Beta vulgaris Chenopodiaceae Paliwal and Narinai, 1965Continued