Pseudomonas syringae infection assays in Arabidopsis.

Pseudomonas syringae pv. tomato DC30000 (Pst DC3000) infection of Arabidopsis thaliana has been widely used to elucidate many of the general principles underlying the plant immune response and bacterial pathogenesis. Study of Pst DC3000 virulence factors has also proven useful in the discovery and elucidation of fundamental mechanisms in plant biology. In particular, Pst DC3000 produces a phytotoxin, coronatine, that is a remarkable molecular mimic of the active form of the plant hormone jasmonate. Here we illustrate several common methods used for Pst DC3000-based assays, including preparation of Pst DC3000 inocula, inoculation of soil-grown Arabidopsis plants, and subsequent bacterial quantification in planta. We also describe how Pst DC3000 infection can be applied to study gene expression and protein degradation associated with jasmonate signaling.