ISSN:
1432-2048
Keywords:
Cyanobacteria
;
Osmoregulation
;
Photosynthesis and salt stress
;
Salt stress
;
Sucrose synthesis and salt stress
;
Synechococcus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Synechococcus PCC 6301 synthesized sucrose as a compatible solute following hyperosmotic shock induced by NaCl. Initial rates of photosynthetic 14C incorporation were reduced following salt shock. Photosynthetic rates were comparable in cells enriched for glycogen (by growth in NO 3 - -deficient medium) and cells grown in NO 3 - -sufficient medium in the absence of osmotic shock. Incorporation of 14C was predominantly into the NaOH fraction and the residual acidic fraction in cells grown in NO 3 - -sufficient medium, whereas incorporation was predominantly into the residual acidic fraction in cells grown in NO 3 - -deficient medium. Following salt stress, 14C incorporation was initially into the ethanol-soluble fraction and the majority of tracer was recovered in sucrose. Carbon-14 was detected in sucrose in cells which had been enriched for [14C]glycogen prior to salt stress, inferring that glycogen can act as a carbon source for sucrose synthesis following salt stress. Changes in the specific activity of sucrose are consistent with an initial synthesis of sucrose from glycogen followed by synthesis of sucrose using newly fixed carbon, in response to salt stress.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00195893
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