Horizontal gene transfer in cowpea (Vigna unguiculata L.Walp) through genetic transformation

Abstract

Cowpea (Vigna ungiuculata L.) is a crop with wide environmental adaptability grown in areas with extreme heat and drought, as well as in humid and wet tropical areas. Cowpea represents a crucial source of protein, especially in sub-Saharan Africa, where more than 70% of the crop is produced and consumed.  Conventional breeding approaches have contributed substantially to the genetic improvement of cowpea. However, non-availability of genes for resistance to pests and viruses and sexual incompatibility with sources of resistance makes the development of insect- and virus-resistant cowpea increasingly difficult. Genetic modification of cowpea with genes of agronomic importance has the potential to overcome these problems. In this review, we summarize the key aspects of cowpea transformation work carried out in research centers around the world. We also discuss the approaches employed and the obstacles militating against efficient regeneration of transgenic cowpea expressing genes of interest.