[The role of intracellular Ca(2+) pools in the regulation of protoplast volume. Effect of red light on the Ca(2+) mobilization in cytoplasm of Arabidopsis cells].
The changes in cytosol Ca2+ concentration associated with the shrinkage of Arabidopsis cells induced by the inhibitor of Ca(2+)-ATPase, cyclopiazonic acid and the Ca2+ ionophore ionomycin were monitored using the fluorescence of Ca(2+)-sensitive probe chlortetracycline hydrochloride. It was found that these compounds elicited a substantial decrease in fluorescence intensity closely associated with Ca(2+)-release from the intracellular stores to the cytoplasm. The release of Ca2+ from the intracellular depots was accompanied by decrease of plant cell volume. Thapsigargin and 2,5'-ditert-butyl-1,4-benzohydroquinone (highly specific inhibitors of Ca(2+)-ATPase of endoplasmic reticulum) resulted in much weaker changes than cyclopiazonic acid did. It was also found with the help of the same technique that red light (lambda = 660 nm) illumination induced a similar Ca2+ release from the intracellular stores. Moreover, the amplitudes of light-induced fluorescence responses registered in mutant plants differing in the content of phytochrome A (phyAOX) and phytochrome B (phyBOX) were much higher than those registered in wild-type of Arabidopsis.
Molchan
O V
OV
Institute of Photobiology, National Academy of Sciences of Belarus, ul. Akademicheskaya 27, Minsk, 220072 Belarus.
Kim
Iu V
IuV
Beliaeva
T V
TV
Dolgachev
V A
VA
Kovalev
A E
AE
Zinchenko
V P
VP
Volotovskiĭ
I D
ID
D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects / Q000648:ultrastructure; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D003593:Cytoplasm / Q000378:metabolism* / Q000528:radiation effects; D007211:Indoles / Q000494:pharmacology; D007259:Infrared Rays; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D011523:Protoplasts / Q000166:cytology* / Q000528:radiation effects / Q000648:ultrastructure; D013050:Spectrometry, Fluorescence
D007211:Indoles; D007476:Ionophores; D015759:Ionomycin; D002118:Calcium; C000543:cyclopiazonic acid