Extracellular ATP And Adenosine Signaling In Arabidopsis: Investigating Cellular Modulation

This study investigates the roles of extracellular ATP (eATP) and adenosine in Arabidopsis thaliana, focusing on root hair elongation and stomatal aperture. The research identifies two lectin receptor kinases, P2K1 and P2K2, as eATP receptors in plant cells. Experiments with ATPγS and an annexin 3 (ANN3) knockout line suggest that ANN3 may mediate calcium-dependent growth responses to eATP. Additionally, pharmacological studies using 2-chloroadenosine, caffeine, and theophylline indicate that adenosine inhibits root hair growth and stomatal opening, suggesting an adenosine-like receptor pathway in Arabidopsis. These findings propose that adenosine antagonizes eATP signaling in plants, similar to mechanisms in animal purinergic signaling, and suggest the potential existence of a GPCR signaling pathway in plants.