Regulation of salt and ABA responses by CIPK14, a calcium sensor interacting protein kinase in Arabidopsis.

Calcium and protein kinase serve as the common mediators to regulate plant responses to multiple stresses including salt and ABA stimulus. Here we reported a novel protein kinase (CIPK14) that regulated the responses to ABA treatment and salt stress in Arabidopsis. CIPK14 transcripts, capable been checked in roots, stems, leaves and flowers, were highly expressed in flowers and roots. CIPK14 was induced by ABA and salt treatments. The disruption of CIPK14 altered the transcriptional pattern of a gene marker line related to ABA and salt responses, and the results suggested that CIPK14 probably was responsible to the control of the salt and ABA responses. Comparing with wild types, the lines inserted with the T-DNA in which CIPK14 gene expression was knocked out were also more sensitive to ABA and salt stimulus, showing low germination rate and the less root elongation. While, when these conditioned seeds were treated with norflurazon, their germination percentages could recover to a certain extent. We also found that exogenous calcium could have an effect on the transcription of CIPK14 under ABA and salt treatments, and it seemed that calcium ion might work upstream CIPK14 to regulate the plant response to ABA and salt response.