Molecular Plant-Microbe Interactions (2014) 27, 1035-1047

Alon Savidor, Laura Chalupowicz, Doron Teper, Karl-Heinz Gartemann, Rudolf Eichenlaub, Shulamit Manulis-Sasson, Isaac Barash and Guido Sessa (2014)
Clavibacter michiganensis subsp. michiganensis Vatr1 and Vatr2 transcriptional regulators are required for virulence in tomato
Molecular Plant-Microbe Interactions 27 (10), 1035-1047
Abstract: The plant pathogen Clavibacter michiganensis subsp. michiganensis is a gram-positive bacterium responsible for wilt and canker disease of tomato. Although disease development is well characterized and diagnosed, molecular mechanisms of C. michiganensis subsp. michiganensis virulence are poorly understood. Here, we identified and characterized two C. michiganensis subsp. michiganensis transcriptional regulators, Vatr1 and Vatr2, that are involved in pathogenicity of C. michiganensis subsp. michiganensis. Vatr1 and Vatr2 belong to TetR and MocR families of transcriptional regulators, respectively. Mutations in their corresponding genes caused attenuated virulence, with the Δvatr2 mutant showing a more dramatic effect than Δvatr1. Although both mutants grew well in vitro and reached a high titer in planta, they caused reduced wilting and canker development in infected plants compared with the wild-type bacterium. They also led to a reduced expression of the ethylene-synthesizing tomato enzyme ACC-oxidase compared with wild-type C. michiganensis subsp. michiganensis and to reduced ethylene production in the plant. Transcriptomic analysis of wild-type C. michiganensis subsp. michiganensis and the two mutants under infection-mimicking conditions revealed that Vatr1 and Vatr2 regulate expression of virulence factors, membrane and secreted proteins, and signal-transducing proteins. A 70% overlap between the sets of genes positively regulated by Vatr1 and Vatr2 suggests that these transcriptional regulators are on the same molecular pathway responsible for C. michiganensis subsp. michiganensis virulence.
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Link to article at publishers website
Database assignments for author(s): Guido Sessa, Shulamit Manulis-Sasson

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Clavibacter michiganensis	Tomato (Solanum lycopersicum)