Genetic Engineering of Banana Against Bacterial Diseases

Banana (Musa spp) is among the top ten most important food crops worldwide in terms of production and consumption. However, banana production is threatened by several bacterial diseases, including Banana Xanthomonas wilt (BXW) caused by Xanthomonas campestris pathovar (pv). musacearum, Moko disease caused by Ralstonia solanacearum, and Blood disease caused by Ralstonia syzygii sub-species (subsp). Celebesensis. Banana Xanthomonas wilt (BXW), caused by Xanthomonas campestris pv. musacearum (Xcm) is the most economically important bacterial disease affecting banana production, particularly in the African Great Lakes region. Banana breeding through conventional approach is key to overcoming yield losses to bacterial phytopathogens. However, conventional breeding of bananas is limited by low male and female fertility and the lack of diversity and important traits in the gene pool. At present, only Musa balbisiana (banana progenitor species) is resistant to BXW, but breeders do not prefer it for breeding because it harbors banana streak virus (BSV) sequences in its B genome, which get activated during abiotic stress, such as drought, leading Banana Streak Disease (BSD). Thus, genetic engineering serves as a viable alternative and complement to conventional breeding for banana improvement. This review highlights the strategies, challenges, status, and prospects of genetic engineering of bananas against bacterial diseases.