Abstract
We report high-quality genomes of three strains of Xanthomonas citri pv . mangiferaeindicae, the causal agent of mango bacterial canker disease, including the pathotype strain of this pathovar and two strains from Burkina Faso that emerged a decade ago. These strains hosted two to three plasmids of sizes ranging from 19 to 86 kb. Genome mining revealed the presence of several secretion systems and effectors involved in the virulence of xanthomonads with (i) a type I secretion system of the hlyDB group; (ii) xps and xcs type II secretion systems; (iii) a type III secretion system with several type III effectors, including transcription activator-like effectors; (iv) several type IV secretion systems associated with plasmid or integrative conjugative elements mobility; (v) three type V secretion system subclasses (Va, Vb, and Vc); and (vi) a single i3* type VI secretion system. The two strains isolated in Burkina Faso from mango ( Mangifera indica) and cashew ( Anacardium occidentale) differed by only 14 single-nucleotide polymorphisms and shared identical secretion systems and type III effector repertoires. Several transcription activator-like effectors were identified in each strain, some of which may target plant genes previously found implicated in disease development in other xanthomonad-associated pathosystems. These results support the emergence in Burkina Faso a decade ago of very closely related strains that became epidemic on mango and cashew (i.e., two distinct host genera of a same plant family). These new genomic resources will contribute to better understanding the biology and evolution of this agriculturally major crop pathogen.