Protein Profiles of Pod Borer Maruca Resistant Transgenic Cowpea

Abstract

The grain legume cowpea Vigna unguiculata (L.) Walp. is a major protein source used for food and feed in Sub-Saharan Africa. The crop is affected by the pod borer Maruca vitrata against which transgenic lines were developed as part of the genetic control approach. This study aimed to assess the protein profiles in seeds and leaves of transgenic cowpea lines and their non-transgenic near-isogenic counterparts. Crude protein content was determined by the Kjeldahl method, and soluble proteins were quantified using Bradford dye binding assay. The average crude protein content ranged between 21.61% and 26.58% in the seeds and between 10.86% and 17.90% in the leaves. Total solubility varied between 13.03% and 20.64%. Osborne’s protein fractions contents in the seeds were 52.41% - 69.52% (albumin), 4.62% - 7.19% (globulin), 7.95% - 11.40% (glutelin) and 3% - 4% (prolamin). In any case, protein content differed significantly between cowpea genotypes but not between pairs of transgenic/non-transgenic lines. Insecticidal Cry1Ab protein expressed by transgenic lines was only detected in the albumin and globulin fractions. Altogether, these findings enhance our understanding of the effects of genetic modification on cowpea protein content and composition, with potential implications for nutritional and safety assessments.