Cowpea trypsin inhibitor

In China, Bt cotton scientists have developed and commercialised their own lines of Bt cotton and cotton with stacked genes (Bt and cowpea trypsin inhibitor) besides Monsanto s approved Bt cotton. Chinese farmers in the Shandong and Hebei provinces of mainland China, who cultivated Bt cotton, used less pesticides than farmers cultivating non Bt cotton (10.3 and 57.8 kg/ha, respectively). Concomitantly, farmers often reduced the number of pesticide sprays from twelve to three or four sprays [17]. In addition, it has been observed that in these provinces in 1999, Bt cotton adoption led to approximately 10% higher yields. This yield effect was geographically dependent, because in other regions the observed benefit was not equally high [18]. 

J.A. and Gatehonse, A.M.R. (2001). Dietary Cowpea trypsin inhibitor (CpTI) affects growth and development of the tomato moth Lacanobia oleracea (Lep-idoptera Noctuidae) and the success of the gregarious ectoparasitoid Eulo-phus pennicornis (Hymenoptera Eulophidae). Pest Manage. Sci. 57,57-66. 

Acute toxicity tests similar to those used to test chemical pesticides, in which 10-day-old adult honey bees were either fed or injected with cowpea trypsin inhibitor (CpTI), showed that an oral dose of 11 jjig per bee and an injected dose of 0.5 jig per bee had no effect on bee survival after 24 or 48 hours [68]. 

Inhibition of trypsin is another mechanism of activity recently discovered in plant defensins. CfDl and CfD2 from Cassia fistula were the first plant defensins to be identified as trypsin inhibitors. Cp-thionin from cowpea was more recently discovered to have inhibitory potency against trypsin. Searches of protein sequence databases have yielded a number of other plant proteins annotated as trypsin inhibitors or potential trypsin inhibitors. These annotations were most likely made on the basis of sequence similarities with other known trypsin inhibitors, namely the Bowman—Birk trypsin inhibitor. Since the actual framework of the disulfide bonds is not known, it is possible that structure and therefore activity differ from this prototype framework. ... 

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