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. eATP, released during stress, triggers a rise in cytoplasmic calcium, activating downstream responses. Two lectin receptor kinases, P2K1 and P2K2, are identified as eATP receptors. Experiments suggest that annexin 3 (ANN3) may mediate calcium-dependent growth responses to eATP. Additionally, pharmacological studies indicate that adenosine inhibits root hair growth and stomatal opening, suggesting an adenosine-like receptor pathway in plants. These findings propose that adenosine antagonizes eATP signaling, similar to animal purinergic signaling, and suggest a potential evolutionary parallel in extracellular nucleotide sensing, with implications for discovering a GPCR signaling pathway in plants.