B. G. Sangeetha <br/><br/>
Insecticidal activity of leaf proteins isolated from tuberous Ipomoea mauritiana against sweetpotato weevil 

 - P 472-478 
<br/><br/> Sweetpotato is one of the most important food crops in<br/>the world and serves as a rich source of carbohydrates,<br/>betacarotene, vitamins and minerals. Sweetpotato<br/>weevil is one of the harmful pests infesting the crop<br/>and remains a challenge for crop cultivation. From<br/>screening of different Ipomoea spp., wild tuberous Ipomoea mauritiana was identified as resistant to sweetpotato weevil infestation. Hence, several extraction<br/>methods for the isolation of proteins from the leaves of<br/>different wild I. mauritiana, Ipomoea palmata, Ipomoea<br/>triloba and Ipomoea obscura were standardised. Further, the crude protein extract from I. mauritiana was<br/>tested against adult sweetpotato weevils using the leaf<br/>dip method. The mortality of the weevils were observed<br/>for crude extract isolated after 48 h at a concentration<br/>of protein ranges from 4 to 5 mg/ml. Further, to study<br/>the effects of crude protein of I. mauriatiana, the protein content and various enzymes from sweetpotato<br/>weevil were estimated after treatment. A significant<br/>reduction in the amount of protein was observed after<br/>treatment with crude leaf protein, which shows the<br/>presence of protease inhibitor activity. Significant difference was observed in the different enzyme activity,<br/>viz. superoxide dismutase, lipid peroxidase, glutathione<br/>peroxidase, glutathione reductase, glutathione s-transferase of sweetpotato weevil, which also reveals the<br/>insecticidal activity of crude protein extract. In conclusion, this is one of the first studies regarding the evaluation of insecticidal activity of leaf protein extract<br/>from the wild I. mauritiana against sweetpotato weevils, and our studies revealed the presence of insecticidal proteins as well as protease inhibitors from the<br/>leaves of I. mauritiana. Further studies will be done to<br/>identify and purify novel proteins from I. mauritiana<br/>using a proteomics approach to evaluate insecticidal<br/>activity against sweetpotato weevil. 
<br/><br/><label>Subjects--Facted Index Terms: </label><br/>Extraction<br/>protease inhibitory assay<br/> Ipomoea sp.<br/>TCA-acetone<br/>sweetpotato<br/>protein