CONTROL OF BANANA XANTHOMONAS WILT DISEASE USING GENETIC ENGINEERING

Abstract

The banana Xanthomonas wilt (BXW) disease, caused by the bacterium Xanthomouas campestris pv. musacearum (XCM), endangers the livelihoods of millions of farmers in the Great Lakes region of East and Central Africa. The disease was first identified in Uganda in 2001 and has since then also been reported in Eastern Democratic Republic of Congo, Rwanda, Kenya and Tanzania. The pathogen kills plants quickly and spreads rapidly over a large area making the disease one of the most dreaded in banana (Musa spp.). The development of disease resistant banana cultivars remains a high priority, since farmers are reluctant to employ labor-intensive disease control measures. Prospects of developing cultivars with resistance to BXW through conventional breeding are limited, as no source of germplasm exhibiting resistance against XCM has been identified. Transgenic technologies for banana may provide a timely and cost-effective alternative solution to the BXW pandemic. The ferredoxin-like amphipathic protein (pflp) and hypersensitive response assisting protein (hrap), isolated from sweet pepper (Capsicum annuum) are novel proteins that can intensify the harpinPSS-mediated hypersensitive response. The International Institute of Tropical Agriculture (IITA) has negotiated royalty-free license from Academia Sinica, Taiwan, patent holder, through the African Agricultural Technology Foundation (AATF) for access to the technology for bacterial wilt resistance. The partners, IITA, the National Agriculture Research Organization (NARO) in Uganda and AATF, have signed a tripartite agreement for development of BXW-resistant transgenic bananas. Hundreds of transgenic lines of banana cultivars have been generated, which are screened for disease resistance under laboratory conditions. Most promising lines will be evaluated for efficacy against XCM in fields.