
TY  - JOUR
A1  - Hibino, T 
A1  - Lee, BH 
A1  - Rai, AK 
A1  - Ishikawa, H 
A1  - Kojima, H 
A1  - Tawada, M 
A1  - Shimoyama, H 
A1  - Takabe, T 
T1  - Salt Enhances Photosystem I Content and Cyclic Electron Flow via NAD(P)H Dehydrogenase in the Halotolerant Cyanobacterium <I>Aphanothece halophytica</I>
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 1996
VL  - 23
IS  - 3
SP  - 321
EP  - 330
KW  - 
UR  - https://doi.org/10.1071/PP9960321 
N2  - To uncover the adaptation mechanisms of photosystems for halotolerance, changes in stoichiometry and activity of photosystems in response to changes of salinities were examined in a halotolerant cyanobacterium, Aphanothece halophytica. Photosynthetic O2 evolution was high even at high salinities. O2 evolution activity increased with increasing external concentration of NaCl, reached a maximum at 1.5 M NaCl, and then decreased. Similar salt dependence was observed for photosystem II activity. On the other hand, photosystem I activity increased concomitantly with increase in salinity. Photoacoustic measurements indicated that appreciable energy storage by photosystem I mediated cyclic electron flow at high salinities. Significant electron donation to photosystem I reaction centres through NAD(P)H-dehydrogenase complexes was observed in high salt media. The contents of cytochrome b6/f and photosystem II were almost constant under various salinity conditions, whereas the levels of chlorophyll &#945;, photosystem I, soluble cytochrome c-553, and NAD(P)H-dehydrogenase increased in the cells grown with high salinities. These results indicate that salt specifically induces an increase of protein levels involving cyclic electron flow around photosystem I that may entail an important role for adaptation of Aphanothece halophytica cells to high salinities. 
ER  -

