Natural variation in Arabidopsis thaliana resistance mechanisms to Pseudomonas syringae
A. VELÁSQUEZ (1), M. Oney (1), B. Huot (1), S. He (1) (1) Michigan State University, U.S.A.

Plants are continuously threatened by pathogen attack, and as such, they have evolved distinct mechanisms to evade, escape, and defend themselves against pathogens. However, it is not known what types of defense mechanisms a plant would already possess to defend against a potential pathogen that has not co-evolved with the plant. The foliar pathogen Pseudomonas syringae pv. tomato (Pst) DC3000 is not a native pathogen of Arabidopsis thaliana. A survey of 1041 accessions of A. thaliana revealed that sixteen of them were resistant to infection by Pst DC3000. These accessions showed different mechanisms of resistance against Pst DC3000. Some accessions were resistant when bacteria were inoculated directly on the leaf surface and not when delivered into the apoplast, other accessions showed an accelerated cell death response reminiscent of a hypersensitive response or had elevated salicylic acid levels which was associated with constitutive accumulation of Pathogenesis-related protein 1 (PR1). A few other accessions did not fall into any of those categories. Evaluation of three mapping populations between different resistant accessions and the susceptible Arabidopsis control (Col-0) revealed that resistance was likely controlled by multiple loci scattered throughout the genome. These results suggest that a wild plant species already possesses diverse latent resistance mechanisms against a potential pathogen highlighting plant foresight against future pathogen attack.    

Abstract Number: P17-632
Session Type: Poster