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.

Biological Activity of Piper aduncum extracts on Anticarsia gemmatalis (Hübner) (Lepidoptera: Erebidae) and Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

“…Some authors have attributed this effect to the presence of peptidase inhibitors, which can be expressed by plants as a defense mechanism (Gahloth et al 2011, Macedo et al 2011, Cruz et al 2013, Ghodke et al 2013 resulting in delayed development of insects.…”

Purification and Partial Characterization of Trypsin-Specific Proteinase Inhibitors from Pigeonpea Wild Relative Cajanus platycarpus L. (Fabaceae) Active against Gut Proteases of Lepidopteran Pest Helicoverpa armigera

“…The identification of high molecular mass TIs in SDS-PAGE, MALDI intact mass analysis, and 2-D activity staining studies together suggest the possibility of existence of MLPs in CpPI 63. Similar to KTIs, MLPs also belonged to Kunitz super family and exhibited inhibitory activity against trypsin and HGPs (Gahloth et al, 2011). In contrast to KTIs, MLPs exist as oligomers by inter molecular disulphide bond, which is evident by the disappearance of high molecular mass TIs in CpPI 63 on reduction with DTT in MALDI-TOF studies and 2-D electrophoresis.…”

Addition of Cinnamon Oil Improves Toxicity of Rotenone toSpodoptera litura(Lepidoptera: Noctuidae) Larvae

“…The larvae were reared in rectangular plastic jars (30 × 20 × 18 cm); the lids were cut (3 × 3 cm) and replaced with a mesh cloth for aeration. Larvae were reared in an environmentally controlled room (25 ± 1 °C, 14:10 h L:D, and 75% relative humidity [RH]) (Baskar et al 2011) and fed with an artificial diet adapted from Gahloth et al (2011). The diet consisted of soy flour (100.0 g), oatmeal (80.0 g), dried brewer yeast (26.0 g), sorbic acid (2.0 g), casein (8.0 g), vitamin C (8.0 g), agar (7.5 g), choline chloride (1.0 g), inositol (0.2 g), cholesterol (0.2 g), formaldehyde (2.0 mL), and distilled water (500.0 mL).…”