A Comparative Study on Toxicity of Recombinant Chitinase on A Polyphagous Pest, Helicoverpa Armigera

Holometabolous insects complete their life cycle in four stages: egg, larva, pupa and adult. The larval stage is characterized by instar on an average most larvae has 4- 6 stages that occurs between molts. One of the essential enzyme for process moulting chitinase. Expression chitinase gene takes place when insect ready to moult, wherein old exoskeleton being made chitin replaced with new exoskeleton. Reports indicate introduction at inappropriate time concentration will prevent formation chitin, resulting no thus growth retardation finally death. Insects own shown be a potential insecticide. In present study, encoding Helicoverpa armigera was isolated sequence found 1734bp as compared reference sequence. expressed prokaryotic eukaryotic host system. protein purified using Ni- NTA column tagged histidine. Chitinase activity determined obtained used toxicity studies against same insect. Injection assay, topical application oral ingestion showed Pichia pastoris recombinant more effective Escherichia coli case injection P. recorded 77% mortality highest used. Topical 58% 40% malformed pupae end E. An significant decrease weight gain observed 2nd day from 7th E.coli studies. Effectiveness might because post translational modifications