Insecticidal action of Bauhinia monandra leaf lectin (BmoLL) against Anagasta kuehniella (Lepidoptera: Pyralidae), Zabrotes subfasciatus and Callosobruchus maculatus (Coleoptera: Bruchidae).
Bruchid beetle larvae cause major losses in grain legume crops throughout the world. Some bruchid species, such as the cowpea weevil (Callosobruchus maculatus) and the Mexican bean weevil (Zabrotes subfasciatus), are pests that damage stored seeds. The Mediterranean flour moth (Anagasta kuehniella) is of major economic importance as a flour and grain feeder; it is often a severe pest in flour mills. Plant lectins have been implicated as antibiosis factors against insects. Bauhinia monandra leaf lectin (BmoLL) was tested for anti-insect activity against C. maculatus, Z. subfasciatus and A. kuehniella larvae. BmoLL produced ca. 50% mortality to Z. subfaciatus and C. maculatus when incorporated into an artificial diet at a level of 0.5% and 0.3% (w/w), respectively. BmoLL up to 1% did not significantly decrease the survival of A. kuehniella larvae, but produced a decrease of 40% in weight. Affinity chromatography showed that BmoLL bound to midgut proteins of the insect C. maculatus. 33 kDa subunit BmoLL was not digested by midgut preparations of these bruchids. BmoLL-fed C. maculatus larvae increased the digestion of potato starch by 25% compared with the control. The transformation of the genes coding for this lectin could be useful in the development of insect resistance in important agricultural crops.
Laboratório de Purificação de Proteínas e suas Funções Biológicas, Departamento de Ciências Naturais, CPTL, Universidade Federal do Mato Grosso do Sul (UFMS), Avenida Capitão Olinto Mancini, Três Lagoas, MS, Brazil. bioplant@terra.com.br
Maria Lígia Rodrigues
ML
Macedo
Maria
M
das Graças Machado Freire
Maria Barbosa Reis
MB
da Silva
Luana Cassandra Breitenbach Barroso
LC
Coelho
D000818:Animals; D036481:Bauhinia / Q000737:chemistry*; D001681:Biological Assay; D002846:Chromatography, Affinity; D001517:Coleoptera / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D019476:Insect Proteins / Q000378:metabolism; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000502:physiology; D007915:Lepidoptera / Q000187:drug effects*; D007928:Lethal Dose 50; D010206:Papain / Q000378:metabolism; D010434:Pepsin A / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry; D037121:Plant Lectins / Q000378:metabolism / Q000494:pharmacology*; D014357:Trypsin / Q000378:metabolism
D019476:Insect Proteins; D007306:Insecticides; D037121:Plant Lectins; D014357:Trypsin; D010206:Papain; D010434:Pepsin A