Calcium signals in the plant nucleus: origin and function

The universality of calcium as an intracellular messenger depends on the dynamics of its spatial and temporal release from calcium stores. Accumulating evidence over the past two decades supports an essential role for nuclear calcium signalling in the transduction of specific stimuli into cellular responses. This review focuses on mechanisms underpinning changes in nuclear calcium concentrations and discusses what is known so far about the origin of the nuclear calcium signals identified, primarily in the context of microbial symbioses and abiotic stresses.