Eva Hiery

Suche


B5 Analysis of virulence factors of Corynebacterium diphtheriae

Principal investigator
Andreas Burkovski

Mentor
Sophia Sonnewald

PhD exam 26.07.2013

Analysis of virulence factors of Clavibacter michiganensis ssp. michiganensis

Advances in the understanding of interaction between bacteria and their host plants are almost entirely restricted to Gram-negative bacteria, because these are the majority of phytopathogenic bacteria. There are only a few Gram-positive phytopathogens, however, some of these are very important since they can damage yields of agriculturally important plants. One example is the species Clavibacter michiganensis. The pathovar C. michiganensis ssp. michiganensis (Cmm) causes wilt and cancer of tomato while C. michiganensis ssp. sepedonicus (Cms) is responsible for ring rot of potato. The two pathogens can destroy complete fields of their corresponding host plant and are quarantine organisms in the EU. Despite their agricultural importance little is known about virulence factors of Cmm and Cms. Eichenlaub and colleagues showed in the recent years, that Cmm carries the two native plasmids pCM1 and pCM2. It could be proven, that these plasmids are responsible for the pathogenicity of Cmm. The plasmid-free strain Cmm100 can colonize tomato plants but do not cause disease symptoms. That indicated that genes for colonization lie on the chromosome and genes for pathogenicity on the two plasmids. Recently two pathogenicity loci celA (pCM1) and pat-1 (pCM2) were described by the group of Eichenlaub. In the course of the doctoral project, the characterization of the infection of host and non-host plant with Cmm and Cms is investigated. Therefore bacterial strains will be electroporated with a gfp-containing plasmid and the GFP-fluorescence in infected tomato plants will be measured. Additionally, the characterization will be conducted by using antibodies directed against the bacterial surface. In addition, surface proteomes of Cmm, Cmm100 and Cms are analyzed by 2D-PAGE and MALDI-ToF-MS to identify differently expressed proteins and for this reason potential virulence factors which will then be knocked out by insertion mutagenesis.

Figure: Different disease symptoms of Solanum lycopersicum caused by Clavibacter michiganensis ssp. michiganensis NCPPB382. Wilting leaves and canker of the stem.

 

Publications

 

Presentations

July 2012 4th Annual Retreat, Erlangen School of Molecular Communication, Kloster Banz, Bad Staffelstein, Germany
Analysis of promoter structures and putative virulence factors of Clavibacter michiganensis subsp. michiganensis
Talk
     
October 2011 First International SFB 796 Conference: Mechanisms of viral host cell manipulations: from plants to humans, Bamberg, Germany
Host pathogen interaction: Tomato plants and Clavibacter michiganensis subsp. michiganensis
Poster
     
March 2012 Annual Conference of the Association for General and Applied Microbiology (VAAM), Tübingen, Germany
Characterization of putative virulence factors in Clavibacter michiganensis subsp. michiganensis
Poster
     
July 2011 3rd Annual Retreat, Erlangen School of Molecular Communication, Kloster Banz, Bad Staffelstein, Germany
Transcriptional analysis of Clavibacter michiganensis subsp. michiganensis virulence gene inductions
Talk
     
July 2011 3nd Annual Retreat, Erlangen School of Molecular Communication, Kloster Banz, Bad Staffelstein, Germany
Host-pathogen interaction: Tomato plants and Clavibacter michiganensis subsp. michiganensis
Poster
     
September 2010 2nd Annual Retreat, Erlangen School of Molecular Communication, Kloster Banz, Bad Staffelstein, Germany
Characterization of the virulence factors of Clavibacter michiganensis subsp. michiganensis
Talk