Abstract
•An oxylipin-dependent signaling pathway controls stomatal defense.•Abscisic acid modulates the biotic stress signal in guard cells.•Distinct mitogen-activated protein kinase modules regulate biotic and abiotic stresses.•Distinct NADPH oxidase isoforms control reactive oxygen species in response to biotic and abiotic stresses.•Salicylic acid is a key signaling step required for stomatal defense.
Recent reports have revealed new guard cell signaling elements that function in stomatal defense in Arabidopsis thaliana (Arabidopsis). We discuss here the role of oxylipins, salicylic acid (SA), and abscisic acid (ABA) in stomatal immunity in response to the bacterial pathogen Pseudomonas syringae.