Genomic diversity and organization of complex polysaccharide biosynthesis clusters in the genus Dickeya

Manish Ranjan, Devanshi Khokhani, Sanjeeva Nayaka, Suchi Srivastava, Zachary P. Keyser, Ashish Ranjan

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


The pectinolytic genus Dickeya (formerly Erwinia chrysanthemi) comprises numerous pathogenic species which cause diseases in various crops and ornamental plants across the globe. Their pathogenicity is governed by complex multi-factorial processes of adaptive virulence gene regulation. Extracellular polysaccharides and lipopolysaccharides present on bacterial envelope surface play a significant role in the virulence of phytopathogenic bacteria. However, very little is known about the genomic location, diversity, and organization of the polysaccharide and lipopolysaccharide biosynthetic gene clusters in Dickeya. In the present study, we report the diversity and structural organization of the group 4 capsule (G4C)/O-antigen capsule, putative O-antigen lipopolysaccharide, enterobacterial common antigen, and core lipopolysaccharide biosynthesis clusters from 54 Dickeya strains. The presence of these clusters suggests that Dickeya has both capsule and lipopolysaccharide carrying O-antigen to their external surface. These gene clusters are key regulatory components in the composition and structure of the outer surface of Dickeya. The O-antigen capsule/group 4 capsule (G4C) coding region shows a variation in gene content and organization. Based on nucleotide sequence homology in these Dickeya strains, two distinct groups, G4C group I and G4C group II, exist. However, comparatively less variation is observed in the putative O-antigen lipopolysaccharide cluster in Dickeya spp. except for in Dickeya zeae. Also, enterobacterial common antigen and core lipopolysaccharide biosynthesis clusters are present mostly as conserved genomic regions. The variation in the O-antigen capsule and putative O-antigen lipopolysaccharide coding region in relation to their phylogeny suggests a role of multiple horizontal gene transfer (HGT) events. These multiple HGT processes might have been manifested into the current heterogeneity of O-antigen capsules and O-antigen lipopolysaccharides in Dickeya strains during its evolution.

Original languageEnglish (US)
Article numbere0245727
JournalPloS one
Issue number2 February
StatePublished - Feb 2021

Bibliographical note

Publisher Copyright:
© 2021 Ranjan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


  • Base Sequence/genetics
  • Dickeya/classification
  • Gene Transfer, Horizontal
  • Genetic Variation
  • Genome, Bacterial
  • Multigene Family
  • O Antigens/biosynthesis
  • Open Reading Frames
  • Phylogeny
  • Plant Diseases/microbiology
  • Sequence Homology

PubMed: MeSH publication types

  • Research Support, Non-U.S. Gov't
  • Journal Article


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