Gene Expression Analysis during Interaction of Tomato and Related Wild Species with Clavibacter michiganensis subsp. michiganensis

Clavibacter michiganensis subsp. michiganensis is a Gram-positive bacterial pathogen causing bacterial wilt and canker of tomato (Solanum lycopersicum), producing economic losses worldwide. In this study, gene expression analysis was conducted using several resistant tomato-related wild species, including Solanum peruvianum LA2157, S. peruvianum LA2172, and Solanum habrochaites LA2128, and a tomato susceptible species, to identify genes involved in disease response. Using cDNA-amplified fragment length polymorphism (AFLP), 403 differentially expressed transcripts were identified. Among those, several genes showed contrasting expression patterns among resistant and susceptible species, including genes involved in the ubiquitin-mediated protein degradation pathway and secretory peroxidase. These genes were up-regulated in resistant species, but down-regulated in susceptible species, suggesting their likely involvement in early plant defense responses following C. michiganensis subsp. michiganensis infection. These identified genes would serve as new candidate bacterial wilt disease resistance genes and should be subjected to further functional analyses to determine the molecular basis of incompatibility between wild species of tomato and C. michiganensis subsp. michiganensis. This would then contribute to the development of more effective and sustainable C. michiganensis subsp. michiganensis control methods.