Abstract
We report here that osmotic effects and ionic effects are both involved in the NaCl-induced inactivation of the photosynthetic machinery in the cyanobacterium Synechococcus sp. PCC 7942. Incubation of the cyanobacterial cells in 0.5 M NaCl induced a rapid and reversible decline and subsequent slow and irreversible loss of the oxygen-evolving activity of photosystem (PS) II and the electron transport activity of PSI. An Na+-channel blocker protected both PSII and PSI against the slow, but not the rapid, inactivation. The rapid decline resembled the effect of 1.0 M sorbitol. The presence of both an Na+-channel blocker and a water-channel blocker protected PSI and PSII against the short- and long-term effects of NaCl. Salt stress also decreased cytoplasmic volume and this effect was enhanced by the Na+-channel blocker. Our observations suggested that NaCl had both osmotic and ionic effects. The osmotic effect decreased the amount of water in the cytosol, rapidly increasing the intracellular concentration of salts. The ionic effect was caused by an influx of Na+ ions through potassium/Na+ channels that also increased concentrations of salts in the cytosol and irreversibly inactivated PSI and PSII.
| Original language | English |
|---|---|
| Pages (from-to) | 1047-1056 |
| Number of pages | 10 |
| Journal | Plant Physiology |
| Volume | 123 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Jan 1 2000 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physiology
- Genetics
- Plant Science
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Ionic and osmotic effects of NaCl-induced inactivation of photosystems I and II in Synechococcus sp. / Allakhverdiev, Suleyman; Sakamoto, Atsushi; Nishiyama, Yoshitaka; Inaba, Masami; Murata, Norio.
In: Plant Physiology, Vol. 123, No. 3, 01.01.2000, p. 1047-1056.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ionic and osmotic effects of NaCl-induced inactivation of photosystems I and II in Synechococcus sp.
AU - Allakhverdiev, Suleyman
AU - Sakamoto, Atsushi
AU - Nishiyama, Yoshitaka
AU - Inaba, Masami
AU - Murata, Norio
PY - 2000/1/1
Y1 - 2000/1/1
N2 - We report here that osmotic effects and ionic effects are both involved in the NaCl-induced inactivation of the photosynthetic machinery in the cyanobacterium Synechococcus sp. PCC 7942. Incubation of the cyanobacterial cells in 0.5 M NaCl induced a rapid and reversible decline and subsequent slow and irreversible loss of the oxygen-evolving activity of photosystem (PS) II and the electron transport activity of PSI. An Na+-channel blocker protected both PSII and PSI against the slow, but not the rapid, inactivation. The rapid decline resembled the effect of 1.0 M sorbitol. The presence of both an Na+-channel blocker and a water-channel blocker protected PSI and PSII against the short- and long-term effects of NaCl. Salt stress also decreased cytoplasmic volume and this effect was enhanced by the Na+-channel blocker. Our observations suggested that NaCl had both osmotic and ionic effects. The osmotic effect decreased the amount of water in the cytosol, rapidly increasing the intracellular concentration of salts. The ionic effect was caused by an influx of Na+ ions through potassium/Na+ channels that also increased concentrations of salts in the cytosol and irreversibly inactivated PSI and PSII.
AB - We report here that osmotic effects and ionic effects are both involved in the NaCl-induced inactivation of the photosynthetic machinery in the cyanobacterium Synechococcus sp. PCC 7942. Incubation of the cyanobacterial cells in 0.5 M NaCl induced a rapid and reversible decline and subsequent slow and irreversible loss of the oxygen-evolving activity of photosystem (PS) II and the electron transport activity of PSI. An Na+-channel blocker protected both PSII and PSI against the slow, but not the rapid, inactivation. The rapid decline resembled the effect of 1.0 M sorbitol. The presence of both an Na+-channel blocker and a water-channel blocker protected PSI and PSII against the short- and long-term effects of NaCl. Salt stress also decreased cytoplasmic volume and this effect was enhanced by the Na+-channel blocker. Our observations suggested that NaCl had both osmotic and ionic effects. The osmotic effect decreased the amount of water in the cytosol, rapidly increasing the intracellular concentration of salts. The ionic effect was caused by an influx of Na+ ions through potassium/Na+ channels that also increased concentrations of salts in the cytosol and irreversibly inactivated PSI and PSII.
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UR - http://www.scopus.com/inward/citedby.url?scp=0033941856&partnerID=8YFLogxK
U2 - 10.1104/pp.123.3.1047
DO - 10.1104/pp.123.3.1047
M3 - Article
C2 - 10889254
AN - SCOPUS:0033941856
VL - 123
SP - 1047
EP - 1056
JO - Plant Physiology
JF - Plant Physiology
SN - 0032-0889
IS - 3
ER -