CIPK9: a calcium sensor-interacting protein kinase required for low-potassium tolerance in Arabidopsis

Abstract

Potassium is one of the major macro-nutrients essential for a number of cellular processes in plants. Low potassium level in the soil represents a limiting factor for crop production. Recent studies have identified potassium transporters that are involved in potassium acquisition, and some of them are critical for potassium nutrition under low potassium conditions. However, little is understood on the molecular components involved in low potassium signaling and responses. We report here the identification of a calcineurin B-like protein-interacting protein kinase (CIPK9) as a critical regulator of low potassium response in Arabidopsis. The CIPK9 gene was responsive to abiotic stress conditions, and its transcript was inducible in both roots and shoots by potassium deprivation. Disruption of CIPK9 function rendered the mutant plants hypersensitive to low potassium media. Further analysis indicated that K + uptake and content were not affected in the mutant plants, implying CIPK9 in the regulation of potassium utilization or sensing processes.

Two Distinct Families of Protein Kinases Are Required for Plant Growth under High External Mg2+ Concentrations in Arabidopsis

“…In this study, we revealed a novel role of subclass III SnRK2s in plant growth under high external Mg 2+ concentrations. Previous studies on CIPK26/3/9/23 have characterized the diverse and distinct functions of each of these CIPK genes (Kim et al, 2003;Li et al, 2006;Xu et al, 2006;Cheong et al, 2007;Pandey et al, 2007;Drerup et al, 2013;Kimura et al, 2013;Lyzenga et al, 2013). Other than the individual functions of CIPK26, CIPK3, CIPK9, and CIPK23, it seems that these CIPK genes also have some overlapping functions in planta, because CIPK26/3/9/23 formed a monophyletic group in the phylogenetic analysis (Supplemental Fig.…”

Molecular cloning and functional characterization of a novel CBL-interacting protein kinase NtCIPK2 in the halophyte Nitraria tangutorum

“…The ectopic expression of CIPK8 exhibits resistance to high glucose concentrations (Gong et al, 2002). CIPK9 and CIPK23 activate K + channels or transporters, and regulate K + uptake under low K + stress (Xu et al, 2006;Pandey et al, 2007;Liu et al, 2013). SOS2/CIPK24 is critical for salt tolerance, maintaining Na + and Ca 2+ homeostasis (Cheng et al, 2004;Qiu et al, 2004).…”

Role of Arabidopsis NHL family in ABA and stress response

“…[17][18][19] In addition to its co-localization with the plasma membrane tethered AtTLP family protein AtTLP11, 9,16 YFP-NHL6 fusion proteins were also observed in the cytosol and on the membrane of small vacuole or vesicles, when transiently expressed in tobacco leaf epidermal cells (Fig. 1A).…”