Abstract
Clavibacter michiganensis is the most economically important grampositive bacterial plant pathogen, with subspecies that cause serious diseases of maize, wheat, tomato, potato, and alfalfa. Much less is known about pathogenesis involving gram-positive plant pathogens than is known for gram-negative bacteria. Comparative genome analyses of C. michiganensis subspecies affecting tomato, potato, and maize have provided insights on pathogenicity. In this study, we identified strains of C. michiganensis subsp. insidiosus with contrasting pathogenicity on three accessions of the model legume Medicago truncatula.We generated complete genome sequences for two strains and compared these to a previously sequenced strain and genome sequences of four other subspecies. The three C. michiganensis subsp. insidiosus strains varied in gene content due to genome rearrangements, most likely facilitated by insertion elements, and plasmid number, which varied from one to three depending on strain. The core C. michiganensis genome consisted of 1, 917 genes, with 379 genes unique to C. michiganensis subsp. insidiosus. An operon for synthesis of the extracellular blue pigment indigoidine, enzymes for pectin degradation, and an operon for inositol metabolism are among the unique features. Secreted serine proteases belonging to both the pat-1 and ppa families were present but highly diverged from those in other subspecies.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 172-185 |
| Number of pages | 14 |
| Journal | Phytopathology |
| Volume | 108 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2018 |
Bibliographical note
Funding Information:This project was supported by funds from the Minnesota Agricultural Experiment Station/Hatch and National Science Foundation grant IOS-1353854 awarded to J. Glazebrook and the United States Department of Agriculture (USDA) Agricultural Research Service Current Research Information System project 5062-12210-002D. Y. Lu was supported by a Monsanto/University of Minnesota Multi-functional Agriculture Initiative Graduate Student Fellowship from Monsanto Co. We thank K. Ophel-Keller, D. Caffier, and D. Opgenorth for providing strains of C. michiganensis subsp. insidiosus; M. Dornbusch for excellent technical help; the University of Minnesota Genomics Center (Saint Paul, MN) for performing the genome sequencing with MiSeq; the Molecular Biology Core at Mayo Clinic (Rochester, MN) for performing the PacBio sequencing; and the Minnesota Supercomputing Institute at the University of Minnesota (Saint Paul, MN) for facilitating the data analysis. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer.