Encoding specificity in plant calcium signalling: Hot-spotting the ups and downs and waves

Abstract

Calcium ions function as intracellular second messengers in regulating a plethora of cellular processes from acclimative stress responses to survival and programmed cell death. The generation of specificity in Ca2+ signals is dependent on influx and efflux from the extracellular milieu, cytosol and intracellular organelles. One aspect of plant Ca2+ signalling that is currently attracting a great deal of interest is how 'Ca2+- signatures', specific spatio-temporal changes in cytosolic-free Ca2+, encode the necessary information to bring about this range of physiological responses. Here, current information is reviewed on how Ca2+- signatures are generated in plant cells and how stimulus-specific information can be encoded in the form of Ca2+-signatures. © 2003 Annals of Botany Company.