Xanthomonas theicola harbours a novel type 3 secretion system
The complete genome sequence of Xanthomonas theicola, the causal agent of canker on tea plants, reveals novel secretion systems in clade-1 xanthomonas.
Xanthomonas theicola is the causal agent of bacterial canker on tea plants. There is no complete genome sequence available for X. theicola, a close relative of the species X. translucens and X. hyacinthi, thus limiting basic research for this group of pathogens. We optained a high quality complete genome sequence for the X. theicola type strain, CFBP 4691T using single-molecule real-time sequencing with a mean coverage of 264X. Genome mining revealed the presence of non-ribosomal peptide synthases, two CRISPR systems, the Xps type 2 secretion system, and the Hrp type 3 secretion system. Surprisingly, this strain encodes an additional type 2 secretion system and a novel type 3 secretion system with enigmatic function, hitherto undescribed for xanthomonads. Four type 3 effector genes were found on complete or partial transposons, suggesting a role of transposons in effector gene evolution and spread.
This genome sequence was obtained in the framework of an international collaboration made possible through COST Action CA16107 EuroXanth (external page www.euroxanth.eu). It fills an important gap to better understand the biology and evolution of the early-branching xanthomonads, also known as clade-1 xanthomonads, which also harbour important forage crop pathogens such as X. translucens pv. graminis or X. t. pv. arrhenatheri.
Citation:
Koebnik R, Burokiene D, Bragard C, Chang C, Fischer-Le Saux M, Kölliker R, Lang J, Leach J, Luna E, Portier P, Sagia A, Ziegle J, Cohen SP and Jacobs J (2020) The complete genome sequence of Xanthomonas theicola, the causal agent of canker on tea plants, reveals novel secretion systems in clade-1 xanthomonads. Phytopathology®
external page https://doi.org/10.1094/PHYTO-07-20-0273-SC