title: Bioinsecticidal activity of Murraya koenigii miraculin-like protein against Helicoverpa armigera and Spodoptera litura.
abstract: Miraculin-like proteins, belonging to the Kunitz superfamily, are natural plant defense agents against pests and predators, and therefore are potential biopesticides for incorporation into pest-resistant crops. Here, a miraculin-like protein from Murraya koenigii was assessed for its in vitro and in vivo effects against two polyphagous lepidopteran insect pests, Helicoverpa armigera and Spodoptera litura. M. koenigii miraculin-like protein (MKMLP) inhibited the trypsin-like activity and total protease activity of H. armigera gut proteinases (HGP) by 78.5 and 40%, respectively, and S.litura gut proteinases (SGP) by 81 and 48%, respectively. The inhibitor was stable and actively inhibited the proteolysis of both HGP and SGP enzymes for up to 72 h. Incorporation of MKMLP into artificial diet adversely affected the growth and development of pests in a dose-dependent manner. After 10 days of feeding on diets containing 200 µM MKMLP, larval weight was reduced to 69 and 44.8% and larval mortality was increased to 40 and 43.3% for H. armigera and S litura, respectively. The LC(50) of MKMLP was 0.34 and 0.22% of the diet for H.armigera and S. litura, respectively. These results demonstrate the efficacy of MKMLP as a potential plant defense agent against H. armigera and S. litura.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Roorkee, Uttaranchal, India.
authors.forename: Deepankar
authors.initials: D
authors.lastname: Gahloth
authors.forename: Umesh
authors.initials: U
authors.lastname: Shukla
authors.forename: Ajanta
authors.initials: A
authors.lastname: Birah
authors.forename: Gorakh P
authors.initials: GP
authors.lastname: Gupta
authors.forename: P Ananda
authors.initials: PA
authors.lastname: Kumar
authors.forename: Harcharan S
authors.initials: HS
authors.lastname: Dhaliwal
authors.forename: Ashwani K
authors.initials: AK
authors.lastname: Sharma
mesh_terms: D000818:Animals; D004064:Digestive System / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000201:enzymology; D009036:Moths / Q000187:drug effects* / Q000201:enzymology; D032101:Murraya / Q000737:chemistry*; D010447:Peptide Hydrolases / Q000378:metabolism; D010572:Pest Control, Biological; D010940:Plant Proteins / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology*; D055550:Protein Stability; D018411:Spodoptera / Q000187:drug effects* / Q000201:enzymology
chemical_list: D007306:Insecticides; D010940:Plant Proteins; D011480:Protease Inhibitors; D010447:Peptide Hydrolases