A Bacterial Tyrosine Phosphatase Inhibits Plant Pattern Recognition Receptor Activation

Move and Countermove Receptors on plant cell surfaces are tuned to recognize molecular patterns associated with pathogenic bacteria. Macho et al. (p. 1509 ; published online 13 March) found that activation of one of these receptors in Arabidopsis results in phosphorylation of a specific tyrosine residue, which in turn triggers the plant's immune response to the phytopathogen Pseudomonas syringae. P. syringae counters by secreting a specifically targeted phosphatase, thus stalling the plant's immune response.