Enhanced tolerance to low K+ stress in tobacco plants, that ectopically express the CBL interacting protein kinase CIPK23 gene
Xue G. Lu L. M. Yang T. Z. Li X. H. Xing X. X. Xu S. X. (2016) Enhanced tolerance to low K+ stress in tobacco plants, that ectopically express the CBL interacting protein kinase CIPK23 gene. Czech J. Genet. Plant Breed. 52: 77 82. Tobacco (Nicotiana tabacum) has a relatively high requirement for potassium (K+ However, the molecular basis of tolerance to low K+ stresses in tobacco still remains unknown. Here, we report the role of a member of the A. thaliana CBL (calcineurin B like) interacting protein kinase (CIPK) family, AtCIPK23, in low K+ stress responses in tobacco. Molecular analyses revealed that the AtCIPK23 gene was successfully transferred into a tobacco cultivar K326 via Agrobacterium tumefaciens mediated transformation. Overexpression of AtCIPK23 in tobacco resulted in increased low K+ tolerance, which was demonstrated by higher dry biomass, longer primary root length, higher K+ content and better growth status of transgenic tobacco plants compared to controls when both were treated in low K+ MS medium and low K+ hydroponics. Moreover, transgenic lines conferred tolerance to low K+ stress by increasing the K+ uptake rate under low K+ conditions. Taken together, these results provide evidence that AtCIPK23 may be involved in the CBL CIPK signalling network in tobacco responses to low K+ stress.