OsDMI3, a Ca2+/calmodulin kinase, integrates and amplifies H2O2 and Ca2+ signaling in ABA-mediated responses

Abscisic acid (ABA) is an important hormone that regulates both plant development and stress responses ( Chen et al., 2020 Chen K. Li G.J. Bressan R.A. Song C.P. Zhu J.K. Zhao Y. Abscisic acid dynamics, signaling, and functions in plants. J. Integr. Plant Biol. 2020; 62: 25-54 Crossref PubMed Scopus (471) Google Scholar ). In the absence of ABA, group A PROTEIN PHOSPHATASE 2Cs (PP2Cs) interact with and inhibit SUCROSE-NON-FERMENTING 1-RELATED KINASES 2 (SnRK2s). When ABA is present, ABA receptor PYRABACTIN RESISTANCE 1 and PYRABACTIN RESISTANCE 1-LIKE PROTEINS bind to and inhibit PP2Cs, allowing phosphorylation and activation of SnRK2s that, in turn, phosphorylate downstream targets, such as transcription factors, ion channels, and transporters (Figure 1).