Negative effects of a nonhost proteinase inhibitor of ~19.8?kDa from Madhuca indica seeds on developmental physiology of Helicoverpa armigera (Hubner).

ABSTRACT: An affinity purified trypsin inhibitor from the seed flour extracts of Madhuca indica (MiTI) on denaturing polyacrylamide gel electrophoresis showed that MiTI consisted of a single polypeptide chain with molecular mass of ~19.8?kDa. MiTI inhibited the total proteolytic and trypsin-like activities of the midgut proteinases of Helicoverpa armigera larvae by 87.51% and 76.12%, respectively, at concentration of 5?µg/mL with an IC50 of 1.75?µg/mL against trypsin like midgut proteinases. The enzyme kinetic studies demonstrated that MiTI is a competitive inhibitor with a K i value of 4.1 × 10(-10)?M for Helicoverpa trypsin like midgut proteinases. In vivo experiments with different concentrations of MiTI in artificial diet (0.5, 1.0, and 1.5%?w/w) showed an effective downfall in the larval body weight and an increase in larval mortality. The concentration of MiTI in the artificial diet to cause 50% mortality (LD50) of larvae was 1.5%?w/w and that to cause reduction in mass of larvae by 50% (ED50) was 1.0%?w/w. Nutritional indices observations suggest the toxic and adverse effects of MiTI on the growth and development of H. armigera larvae. The results suggest a strong bioinsecticidal potential of affinity purified MiTI which can be exploited in insect pest management of crop plants.

SUBMITTER: Jamal F 

PROVIDER: S-EPMC4179944 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature