SRF6 Is Necessary for the Perception of the Cell Wall Component TGA by Arabidopsis thaliana and Its Subsequent Immune Reaction.

Abstract

Plants are sessile organisms and must accurately respond to a host variety of growth, developmental, and environmental signals throughout their life to maximize fitness. Plant cell surface receptor-like kinases are ideal for the perception of such signals and their transduction within the cell. The Strubbelig Receptor Family (SRF) is a group of leucine-rich repeat receptor-like kinases, several of which have unknown function. Here, we identify a role for SRF6 in the perception of cell wall damage and the activation of downstream immune responses. We show that SRF6 is necessary for proper immune responses following elicitation with a short-chain oligogalacturonic acid, including activation of defense genes and increased bacterial resistance. We also demonstrated the srf6 mutants are more sensitive to isoxaben treatment, suggesting enhanced cell wall integrity maintenance responses. These findings are compatible with the hypothesis that cell wall integrity maintenance responses are elevated when pattern-triggered immunity is compromised.