TY - JOUR
T1 - Salt stress-induced cytoplasmic acidification and vacuolar alkalization in nitellopsis obtusa cells
T2 - In vivo 31p-nuclear magnetic resonance study
AU - Katsuhara, Maki
AU - Kuchitsu, Kazuyuki
AU - Takeshige, Kazuhiko
AU - Tazawa, Masashi
N1 - Publisher Copyright:
© 1989 American Society of Plant Biologists. All rights reserved.
PY - 1989/7
Y1 - 1989/7
N2 - Time courses of cytoplasmic and vacuolar pH changes under salt stress were monitored by in vivo31P-nuclear magnetic resonance spectroscopy in intact cells of Nitellopsis obtusa. When cells were treated with 100 millimolar NaCl for 2 hours, the cytoplasmic pH deceased from 7.2 to 7.0, while the vacuolar pH increased from 4.9 to 5.2. This salt-induced breakdown of the pH gradient between the cytoplasm and the vacuole was also confirmed through direct measurements of change in vacuolar pH with a micro-pH electrode. We speculate that the intracellular pH changes induced by the salt stress mainly results from the inhibition of the H+-translocating pyrophosphatase in the vacuolar membrane, since this H+-translocating system is sensitive to salt-induced increase in the cytoplasmic [Na+] and a simultaneous decrease in the cytoplasmic [K+]. Since disturbance of the cytoplasmic pH value should have serious consequences on the homeostasis of living cells, we propose that the salt-induced intracellular pH changes are one of initial and important steps that lead to cell death.
AB - Time courses of cytoplasmic and vacuolar pH changes under salt stress were monitored by in vivo31P-nuclear magnetic resonance spectroscopy in intact cells of Nitellopsis obtusa. When cells were treated with 100 millimolar NaCl for 2 hours, the cytoplasmic pH deceased from 7.2 to 7.0, while the vacuolar pH increased from 4.9 to 5.2. This salt-induced breakdown of the pH gradient between the cytoplasm and the vacuole was also confirmed through direct measurements of change in vacuolar pH with a micro-pH electrode. We speculate that the intracellular pH changes induced by the salt stress mainly results from the inhibition of the H+-translocating pyrophosphatase in the vacuolar membrane, since this H+-translocating system is sensitive to salt-induced increase in the cytoplasmic [Na+] and a simultaneous decrease in the cytoplasmic [K+]. Since disturbance of the cytoplasmic pH value should have serious consequences on the homeostasis of living cells, we propose that the salt-induced intracellular pH changes are one of initial and important steps that lead to cell death.
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U2 - 10.1104/pp.90.3.1102
DO - 10.1104/pp.90.3.1102
M3 - Article
AN - SCOPUS:84969903546
VL - 90
SP - 1102
EP - 1107
JO - Plant Physiology
JF - Plant Physiology
SN - 0032-0889
IS - 3
ER -