Ca2+ oscillations in plant cells: initiation by rapid elevation in cytosolic free Ca2+ levels.
Temporal increases in intracellular [Ca2+] are now recognized to be key triggers for a wide range of important physiological events in eukaryotic cells. In mammalian cells, signal-induced Ca2+-elevations have been found to be of a pulsatile nature and Ca2+ spikes display a high degree of spatiotemporal complexity. In plant cells a similar picture is beginning to emerge. To investigate the occurrence of pulsatile Ca2+ signals in plant cells we studied alterations of [Ca2+] in the tip region of pollen tubes from poppy (Papaver rhoeas). Time-Resolved Laser Scanning Confocal Microscopy of pollen tubes microinjected with the Dextran-linked Ca2+-indicator dyes Calcium Green or Indo-1 revealed that highly regular Ca2+ oscillations occur in these cells. We further demonstrate that artificial elevation of cytosolic Ca2+ by photolysis of caged-Ca2+ (Nitr-5) can trigger the onset of oscillations.
Calder
G M
GM
Department of Cell Biology, John Innes Centre, Norwich, United Kingdom.
Franklin-Tong
V E
VE
Shaw
P J
PJ
Drøbak
B K
BK
D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D007700:Kinetics; D018613:Microscopy, Confocal; D010207:Papaver / Q000166:cytology / Q000378:metabolism*; D010946:Plants, Medicinal
D002118:Calcium