The role of the CBL-CIPK calcium signalling network in regulating ion transport in response to abiotic stress

Abstract

Plants are sessile organisms and have multiple tolerance mechanisms which allow them to adapt to the environmental stresses to which they may be exposed. Key to a plant’s tolerance of abiotic stresses is the ability to rapidly detect stress and activate the appropriate stress response mechanism. The calcineurin B-like (CBL) and CBL-interacting protein kinase (CIPK) signalling pathway is a flexible Ca2+ signalling network which allows a plant to fine tune its response to stress, via both pre- and post-translational mechanisms. Genes encoding CBLs and CIPKs have now been identified in a variety of plant species. Plants have been found to have large gene families of CBLs and CIPKs, each encoding proteins with specific upstream and downstream targets, thus providing the flexibility required to allow a plant to adapt to a variety of stresses. Characterisation of CBL and CIPK mutants have shown them to be important for a plant to survive cold, drought, heat, salinity and low nutrient stresses. Many CBLs and CIPKs have been shown to be involved in the transport of ions through a plant, either limiting the supply of toxic ions to certain tissues or maximising the uptake of beneficial nutrients from the soil. This review will provide an update into the current knowledge of CBL and CIPK interactions and their role in ion transport during abiotic stress.