Assessment of Seed Protein Quality of A Transgenic Chickpea Event Expressing Cry2Aa Protein

Abstract

Background: Evaluation of the nutritional composition of genetically modified (GM) crops is mandatory for their deregulation. Chickpea is known for its high-quality protein and demonstrating that the seed protein quality of transgenic chickpea remains unaltered is important for its acceptance. Amino acid content, seed storage protein profile and the digestibility of chickpea protein are important determinants of seed protein quality. Thus, in the present study, we assessed the effect of Bt (Cry2Aa) gene expression on the Bt chickpea seed protein quality. Methods: We assessed the amino acid profile, in vitro protein digestibility and factors affecting protein digestibility like trypsin inhibitor, tannins and phytic acid contents of the transgenic Bt chickpea expressing a codon modified Cry2Aa gene and its non-transgenic counterpart. Furthermore, the seed storage proteins were also fractionated and separated on SDS-PAGE followed by mass spectroscopy of the major peptides. Result: Amino acid profile and factors affecting protein digestibility revealed no significant variations between transgenic and non-transgenic chickpeas. Seed storage protein profile confirmed the presence of legumin, vicilin and albumin. No potential change in the digestibility pattern of seed proteins was revealed. Our findings suggest no potential unintended changes in chickpea seed protein quality due to the expression of Cry2Aa gene.