Cassava Bacterial Blight: Using Genomics for the Elucidation and Management of an Old Problem

Bacterial Blight is an important disease of cassava, causing losses that have resulted in historical famines in certain growing zones. The disease is caused by Xanthomonas axonopodis pv. manihotis, a gram-negative rod that belongs to the gammaproteobacteria. In this review, we describe the pathosystem and the recent studies that have been undertaken to elucidate both susceptibility and resistance mechanisms in cassava, with the hope of generating resistant plants using biotechnology. We first describe studies of the pathogen, including pathogen population changes through time as well as genomic tools that have recently been generated to determine pathogenicity factors. Secondly, we discuss mechanisms of disease resistance that have been elucidated in recent years and how these mechanisms could be used for the generation of improved plants resistant to CBB.