title: Purification of Colocasia esculenta lectin and determination of its anti-insect potential towards Bactrocera cucurbitae.
abstract: The present study reports the purification of a lectin from Colocasia esculenta (L.) Schott corms and evaluation of its anti-insect potential towards Bactrocera cucurbitae (Coquilett). The lectin was found to be specific towards N-acetyl-D-lactosamine (LacNac), a disaccharide and asialofetuin, a desialylated serum glycoprotein in hemagglutination inhibition assay. Asialofetuin was used as a ligand to purify Colocasia esculenta agglutinin (CEA) by affinity chromatography. The purity of CEA was ascertained by the presence of a single band in reducing SDS-PAGE at pH 8.3. The affinity purified CEA was employed in artificial diet bioassay of second instar larvae (64-72 hr old) of the B. cucurbitae at concentrations ranging between 10-160 microg ml(-1). The lectin significantly (p < 0.01) decreased the percent pupation and emergence with respect to control. Effect on various enzymes was studied by employing LC50 (51.6 microg ml(-1)) CEA in the artificial diet bioassay of second instar larvae. All the enzymes tested namely esterases, phosphatases (acid and alkaline), superoxide dismutases, catalase and glutathione-S-transferase showed a significant (p < 0.01, p < 0.05) increase in their enzyme and specific activities. These results showed that CEA affected normal growth and development and presented stress to the larvae, activating their detoxification and anti-oxidant systems. Thus, the lectin seems to be a useful candidate for the control measures of B. cucurbitae under the integrated pest management (IPM) system.
authors.affiliation: Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar-143 005, India.
authors.forename: Kshema
authors.initials: K
authors.lastname: Thakur
authors.forename: Manpreet
authors.initials: M
authors.lastname: Kaur
authors.forename: Satwinder
authors.initials: S
authors.lastname: Kaur
authors.forename: Amritpal
authors.initials: A
authors.lastname: Kaur
authors.forename: Sukhdev Singh
authors.initials: SS
authors.lastname: Kamboj
authors.forename: Jatinder
authors.initials: J
authors.lastname: Singh
mesh_terms: D000818:Animals; D031060:Colocasia / Q000737:chemistry*; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D037121:Plant Lectins / Q000737:chemistry / Q000494:pharmacology*; D033621:Tephritidae / Q000187:drug effects*
chemical_list: D007306:Insecticides; D037121:Plant Lectins