AtCIPK19 aggrandizes polyamines-involved cold stress tolerance in plant cells

The CALCINEURIN B-LIKE PROTEIN-INTERACTING PROTEIN KINASEs (CIPKs) play important roles in regulating ion homeostasis and stress responses. However, molecular mechanism of the Arabidopsis (Arabidopsis thaliana) CALCINEURIN B-LIKE PROTEIN-INTERACTING PROTEIN KINASE19 (CIPK19) enhanced cold stress tolerance is not fully understood. Here, we report that overexpression of the Arabidopsis CIPK19 gene (AtCIPK19) results in increasing cell viability and growth rate under cold stress in O. sativa, G. hirsutum, and P. strobus. AtCIPK19 increases cold stress tolerance by decreases the thiobarbituric acid reactive substances (TBARS) and increases the levels of putrescine (Put), spermidine (Spd), and spermine (Spm). In AtCIPK19 transgenic rice cell lines, the transcript levels of genes associated with biosynthesis of Put, Spd, and Spm include OsADC1, OsADC2, OsADC3, OsODC1, OsODC2, OsODC3, OsCPA1, OsCPA2, OsCPA3, OsAIH, OsSAMDC1, OsSAMDC2, OsSAMDC3, OsSAMDC4, OsSAMDC5, OsSAMDC6, OsSPD/SPM1, OsSPD/SPM2, OsSPD/SPM3, and OsSPD/SPM4 are increased under cold stress. These results will increase our understanding of AtCIPK19-related cold stress tolerance in different plant species and are valuable in plant molecular breeding application. Keywords: CALCINEURIN B-LIKE PROTEIN; Cold stress; Pinus; Putrescine; Spermidine; Spermin