Extracellular ATP Induces Nitric Oxide Production in Tomato Cell Suspensions

In plant as well as in animal systems, extracellular ATP (eATP) regulates a broad range of physiological processes. In animals, downstream signaling events regulated by eATP have been described before. Among the second messengers reported to be involved in eATP signaling, there are inositol phosphates, Ca2+, cAMP, and nitric oxide (NO; Abbracchio and Burnstock, 1998; Shen et al., 2005), but in plants this study is in its infancy. It has been shown that Ca2+ and superoxide are required for ATP-induced responses (Demidchik et al., 2003; Song et al., 2006). Here, we report that exogenous ATP induces NO production in plant cells via P2-like receptors accordingly to what has been revealed in animals (Shen et al., 2005, 2006). Even though the data are consistent with the presence of P2-like receptors in plants, they have not been identified yet. Thus, our results suggest that eATP-mediated production of NO is present in different biological systems.