Calcium ions (Ca2+) are well known signaling molecules in plant signal transduction pathways including the response to abiotic stress. Particular stimuli cause specific transient elevations in cytosolic Ca2+ ([Ca2+]cyt) with a stimulus-dependent amplitude and temporal pattern. These Ca2+ transients, known as Ca2+ signatures, rely on the counteractive activities of Ca2+-permeable channels and Ca2+-transporting proteins. Whereas the channels causing an increase in [Ca2+]cyt were partly identified, direct evidence for the role of Ca2+-transporting proteins in the determination of Ca2+ signatures was missing. We recently reported on the functional characterization of a stress-responsive PIIB-type Ca2+-ATPase (PCA1) from the moss Physcomitrella patens. This study revealed an essential role of this Ca2+ pump in the adjustment of salt stress tolerance. Most strikingly, the generation of a specific Ca2+ signature in response to salt was abolished in Physcomitrella mutant lines lacking PCA1 activity. Thus, we can provide a direct link for the function of a Ca2+-ATPase in the generation of a specific Ca2+ signature in plants
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.