Cowpea Vicilins: Fractionation of Urea Denatured Sub-Units and Effects on Callosobruchus maculatus F. (Coleoptera: Bruchidae) Development

Abstract

Vicilins (7S storage globulins) isolated from cowpea (Vigna unguiculata L.) seeds which were susceptible (S) and resistant (R) to the cowpea weevil (Callosobruchus maculatus F., Coleoptera: Bruchidae) were denatured by urea and fractionated by ion-exchange chromatography. Isolated fractions were incorporated in artificial seeds for assessment of their toxicity to C. maculatus. The most acidic fractions of both susceptible (CE-31 cultivar) and resistant (IT81D-1045 line) seeds were shown to affect development and survival of the bruchid. Results indicated that vicilin polypeptides of toxic nature were expressed in both types of storage globulins although at different levels.<br>Vicilinas (globulinas de reserva 7S) isoladas de sementes de feijão-de-corda (Vigna unguiculata L.), susceptíveis (S) e resistentes (R) ao caruncho/gorgulho (Callosobruchus maculatus F., Coleoptera: Bruchidae) foram desnaturadas por uréia e fracionadas por cromatografia de troca iônica. As frações isoladas foram incorporadas em sementes artificiais para avaliação de sua toxicidade a C. maculatus. As fracões mais ácidas de ambas vicilinas afetaram o desenvolvimento e a sobrevivência do bruquídeo. Sugerimos que polipeptídeos de vicilinas de natureza tóxica são expressos em ambos tipos de globulinas de reserva, embora em níveis diferentes

Characterization of the Proteins from Vigna unguiculata Seeds

“…Vicilin from cowpea has been shown to strongly associate with chitin, chitosan, and fully acetylated chitin (8). For this reason, this protein has been shown to bind to fungal structures, interfering with the germination of spores or conidia from a variety of fungi (9) and inhibiting yeast growth (10,11), and to chitinous structures of the midgut of the cowpea weevil (Callosobruchus maculatus), thus interfering with the insect development (12)(13)(14). Antimicrobial peptides (15), pathogenesis related (PR) proteins that inhibit the growth of fungi and insects (16), and proteins with antiviral and antifungal potency (17) have also been detected in cowpea seeds.…”

Effects of a Chitin Binding Vicilin from Erythrina velutina Seeds on Bean Bruchid Pests (Callosobruchus maculatus and Zabrotes subfasciatus)

“…Storage proteins of the 7S vicilin type from cultivar IT81D-1045 of Vigna unguiculata and others from legumi-*Address correspondence to this author at the Laboratório de Química e Função de Proteínas Bioativas, Departamento de Bioquímica, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Tel: 59072-970; Fax: +55842119208; E-mail: msales@cb.ufrn.br nous seeds have been included as some of the most recent defensive protein plant groups [7][8][9][10][11][12]. The involvement of vicilins in the resistance of cowpea seeds to C. maculatus was first suggested during investigations into the possible role of trypsin inhibitors in this process.…”

Effects of a Chitin-Binding Vicilin fromEnterolobium contortisiliquumSeeds on Bean Bruchid Pests (Callosobruchus maculatusandZabrotes subfasciatus) and Phytopathogenic Fungi (Fusarium solaniandColletrichum lindemuntianum)

“…Storage proteins of the 7S vicilin type from cultivar IT81D-1045 of Vigna unguiculata and others from leguminous seeds have been included as some of the most recent defensive protein plant groups ( − ). The involvement of vicilins in the resistance of cowpea seeds to C. maculatus was first suggested during investigations into the possible role of trypsin inhibitors in this process.…”