Clavibacter michiganensis subsp. michiganensis: first steps in the understanding of virulence of a Gram-positive phytopathogenic bacterium.
Clavibacter michiganensis subsp. michiganensis is a plant-pathogenic actinomycete. It infects tomato, spreads through the xylem and causes bacterial wilt and canker. The wild-type strain NCPPB382 carries two plasmids, pCM1 and pCM2. The cured plasmid-free derivative CMM100 is still able to colonize tomato, but no disease symptoms develop indicating that all genes required for successful infection, establishment and growth in the plant reside on the chromosome. Both plasmids carry one virulence factor, a gene encoding a cellulase, CelA in case of pCM1 and a putative serine protease Pat-1 on pCM2. These genes can independently convert the non-virulent strain CMM100 into a pathogen causing wilt on tomatoes. Currently, genome projects for Cmm and the closely related potato-pathogen C. michiganensis subsp. sepedonicus have been initiated. The data from the genome project shall give clues on further genes involved in plant-microbe interaction that can be tested experimentally. Especially, identification of genes related to host-specificity through genome comparison of the two subspecies might be possible.
Gartemann
Karl-Heinz
KH
Lehrstuhl Gentechnologie/Mikrobiologie, Fakultät für Biologie, Universität Bielefeld, Universitätsstrasse 25, D-33501 Bielefeld, Germany.
Kirchner
Oliver
O
Engemann
Jutta
J
Gräfen
Ines
I
Eichenlaub
Rudolf
R
Burger
Annette
A
D000192:Actinomycetales / Q000145:classification / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D006094:Gram-Positive Bacteria; D018551:Solanum lycopersicum / Q000382:microbiology*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology*; D013045:Species Specificity