Genome dynamics mediated by repetitive and mobile elements in Xanthomonas citri pv. durantae

Abstract

Xanthomonas is a highly evolved group of phytopathogenic bacteria infecting nearly 400 host plants having vast genomic resources available with heterogenicity in representation from different species and pathovars. Unfortunately, the wealth of data is extremely biased and restricted to a few Xanthomonas pathogens that infect economically important plants, while those reported to infect the most diverse plants remain neglected. In the present study, we report the first complete genome sequence of Xanthomonas citri pv. durantae that was reported to infect Duranta repens L. or golden dewdrop, a hedge plant of ornamental importance native to the American region. Phylogenomic analysis with its closest relatives placed it amongst X. citri pv. citri A* pathotype strains and further comparative studies revealed various large unique genomic regions of chromosomal origin. The association of integrative and conjugative elements and prophages with unique genomic regions suggests the role of mobilome in genome dynamics. A large number of IS elements and transcription activator-like effectors encoding genes on each of the four plasmids indicate the further scope of diversification in Xanthomonas.