Arabidopsis calcium-dependent protein kinase AtCPK1 plays a positive role in salt/drought-stress response ($)

Ca²⁺-dependent protein kinases (CPKs) can transfer calcium signals via phosphorylation events, a signaling process important for plant development and response to environmental stresses. With the multitude of CPKs thus far identified and their overlapping roles in both abiotic and biotic stress response, more information is needed to elucidate the roles of individual CPKs. Huang et al. focus on the role of AtCDPK1 in salt and drought stress. Arabidopsis cpk1 mutants were hypersensitive to salt stress while OE plants showed enhanced growth and survival under the same salt stress compared to WT plants. This trend was also seen in response to drought stress. Interestingly, cpk1 mutants had increased levels of H₂O₂ while OE plants had reduced H₂O₂ accumulation under both stresses. Furthermore, salt treatment also decreased the expression levels of several stress-inducible genes in the mutants, but these genes were increased in the OE lines. These data provide evidence for the role of AtCPK1 in positively regulating plant response to salinity and drought.  (Summary by Alecia Biel) Biochem. Biophys. Res. Commun. 10.1016/j.bbrc.2017.11.175