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.