Effect of Partially Purified Subabul (Leucaena leucocephala) Proteinase Inhibitors on Helicoverpa armigera and Different Fungal Species

Enzyme inhibitors especially the Proteinase Inhibitors (PIs) is one of the important defensestrategies that plants have adapted against predators. Ornamental tree Subabul is reported to have proteinase inhibitors (PIs) that inhibit digestive enzymes in insect gut. Therefore, evaluation of antifungal, antibacterial and anti-insecticidal activity of partially purified Subabul proteinase inhibitors (STI) was dose the effect of different diets incorporated with STI on proteolytic activity of gut enzymes of the polyphagous pest, H. armigera evaluated. Low-molecular weight STI inhibited Helicoverpa armigera gut enzymes up to 64.36% and High-molecular weight STI up to 41.40%. Per cent inhibition ranged from ≃2%-9% for both the inhibitors, which is very slight. Five of the pathogenic fungi gave negligible effect and in others no significant effect was observed. The results from this collectively suggest that both LSTI and HSTI are very effective control against H. armigera.Howeverthe inhibitors did not exhibit antiproteolytic activity against proteinases from fungal and bacterial isolates examined.