A host-pathogen interactome uncovers phytopathogenic strategies to manipulate plant ABA responses.

The phytopathogen Pseudomonas syringae delivers into host cells type III secreted effectors (T3SEs) that promote virulence. One virulence mechanism employed by T3SEs is to target hormone signaling pathways to perturb hormone homeostasis. The phytohormone abscisic acid (ABA) influences interactions between various phytopathogens and their plant hosts, and has been shown to be a target of P.

Arabidopsis ETHYLENE RESPONSE FACTOR 8 (ERF8) has dual functions in ABA signaling and immunity.

Background: ETHYLENE RESPONSE FACTOR (ERF) 8 is a member of one of the largest transcription factor families in plants, the APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) superfamily. Members of this superfamily have been implicated in a wide variety of processes such as development and environmental stress responses.

Results: In this study we demonstrated that ERF8 is involved in both ABA and immune signaling.

The roles of ABA in plant-pathogen interactions.

Defence against abiotic and biotic stresses is crucial for the fitness and survival of plants under adverse or suboptimal growth conditions. The phytohormone abscisic acid (ABA) is not only important for mediating abiotic stress responses, but also plays a multifaceted and pivotal role in plant immunity. This review presents examples demonstrating the importance of crosstalk between ABA and the key biotic stress phytohormone salicylic acid in determining the outcome of plant--pathogen interactions.