AUTHOR=Shah Syed Mashab Ali , Khojasteh Moein , Wang Qi , Taghavi S. Mohsen , Xu Zhengyin , Khodaygan Pejman , Zou Lifang , Mohammadikhah Sedighe , Chen Gongyou , Osdaghi Ebrahim 

TITLE=Genomics-Enabled Novel Insight Into the Pathovar-Specific Population Structure of the Bacterial Leaf Streak Pathogen Xanthomonas translucens in Small Grain Cereals

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.674952

DOI=10.3389/fmicb.2021.674952

ISSN=1664-302X

ABSTRACT=<p>The Gram-negative bacterium <italic>Xanthomonas translucens</italic> infects a wide range of gramineous plants with a notable impact on small grain cereals. However, genomics-informed intra-species population structure and virulence repertories of the pathogen have rarely been investigated. In this study, the complete genome sequences of seven <italic>X. translucens</italic> strains representing an entire set of genetic diversity of two pathovars <italic>X. translucens</italic> pv. <italic>undulosa</italic> and <italic>X. translucens</italic> pv. <italic>translucens</italic> is provided and compared with those of seven publicly available complete genomes of the pathogen. Organization of the 25 type III secretion system genes in all the 14 <italic>X. translucens</italic> strains was exactly the same, while TAL effector genes localized singly or in clusters across four loci in <italic>X. translucens</italic> pv. <italic>translucens</italic> and five to six loci in <italic>X. translucens</italic> pv. <italic>undulosa</italic>. Beside two previously unreported endogenous plasmids in <italic>X. translucens</italic> pv. <italic>undulosa</italic>, and variations in repeat variable diresidue (RVD) of the 14 strains, <italic>tal1a</italic> of <italic>X. translucens</italic> pv. <italic>translucens</italic> strain XtKm8 encode the new RVDs HE and YI which have not previously been reported in xanthomonads. Further, a number of truncated <italic>tal</italic> genes were predicted among the 14 genomes lacking conserved <italic>Bam</italic>HI site at N-terminus and <italic>Sph</italic>I site at C-terminus. Our data have doubled the number of complete genomes of <italic>X. translucens</italic> clarifying the population structure and genomics of the pathogen to pave the way in the small grain cereals industry for disease resistance breeding in the 21st century’s agriculture.</p>