Extracellular ATP-induced defense transcriptome in Arabidopsis thaliana

Adenosine 5’-triphosphate (ATP) is not only an essential metabolite of cellular biochemistry, but also acts as a signal in the extracellular milieu. In Arabidopsis thaliana, extracellular ATP is monitored by the lectin receptor kinase P2K1, also known as DORN1. Recent studies have revealed that extracellular ATP acts as a damage associated molecular pattern in plants and its signaling through P2K1 is important for mounting an effective defense response against various pathogenic microorganisms. Biotrophic and necrotrophic pathogens attack plants using different strategies, for which plants respond accordingly with salicylate-based and jasmonate/ethylene-based defensive signaling, respectively. Defense mediated by P2K1 is effective against pathogens of both lifestyles, raising the question of the level of interplay between extracellular ATP signaling and that of jasmonate, ethylene, and salicylate. To address this idea, we analyzed ATP-induced transcriptomes in wild-type Arabidopsis seedlings and mutant seedlings defective in essential components in the signaling pathways of jasmonate, ethylene, and salicylate, classic defense hormones, as well as a mutant and a overexpression line of the P2K1 receptor.