Effects of chloramphenicol on photosynthesis, protein profiles and transketolase activity under extremely high CO2 concentration in an extremely-high-CO2-tolerant green microalga, Chlorococcum littorale
2004
Satoh, A. (Marine Biotechnology Inst., Kamaishi, Iwate (Japan)) | Kurano, N. | Harayama, S. | Miyachi, S.
An extremely-high-CO2-tolerant alga, Chiorococcum littorale, showed high quantum efficiency of PSII (?II,) in the light at 40% CO2, as well as at 5% CO2. However, ?II decreased greatly when chloramphenicol (CAP) was added at 40% CO2, while no such decrease was observed at 5% CO2. Cycloheximide showed no effect on ?II at either 5% or 40% CO2. The amount of a 76 kDa polypeptlde (p sup(76)) on SDS-PAGE decreased markedly in the presence of CAP at 40% CO2 but not at 5% CO2. A partial amino acid sequence of p sup(76) was 71-100% identical (10-14 identical residues out of 14 amino acids determined) to those of transketolases (TKLs) reported in higher plants and a cyanobacterium, In agreement with these observations, the TKL activity in C. littorale was decreased by CAP at 40% CO2, but not at 5% CO2. The transient decrease in TKL activity caused by CAP under 40% CO2 was well correlated with that in ?II. These results indicate that the addition of CAP directly or indirectly influences the stability of TKL in C. littorale at 40% CO2, but not at 5% CO2, and that photosynthetic activity was reduced by a decrease in TKL activity.
显示更多 [+] 显示较少 [-]