Involvement of digalactosyldiacylglycerol in cellular thermotolerance in Synechocystis sp. PCC 6803.
The effects of digalactosyldiacylglycerol (DGDG) deficiency on photosynthesis at high temperatures were examined using a dgdA mutant of Synechocystis sp. PCC 6803 incapable of DGDG biosynthesis. The dgdA mutant cells showed significant growth retardation when the temperature was increased from 30 to 38 degrees C, although wild-type cells grew normally. The degree of growth retardation was enhanced by increasing light intensity. In addition, dgdA mutant cells showed increased sensitivity to the photoinhibition of photosynthesis when illuminated at 38 degrees C. Analysis of photosynthesis in intact cells suggested that the inhibition of repair processes and accelerated photodamage resulted in growth retardation in dgdA mutant cells at high temperatures.
Mizusawa
Naoki
N
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
Sakata
Shinya
S
Sakurai
Isamu
I
Sato
Naoki
N
Wada
Hajime
H
D038983:Galactolipids / Q000096:biosynthesis*; D006358:Hot Temperature; D019811:Hydroxylamine / Q000494:pharmacology; D009154:Mutation; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000187:drug effects; D013312:Stress, Physiological; D046939:Synechocystis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
D038983:Galactolipids; D045332:Photosystem II Protein Complex; C007388:digalactosyldiacylglycerol; D019811:Hydroxylamine