Table III.
Inhibition of PSII activity by quinones in intact cells of the wild type and the pgsA mutant of Synechocystis sp. PCC6803
| Strain | Quinone | PG | Photosynthetic Activity |
|---|---|---|---|
| μmol O2 mg Chl−1 h−1 | |||
| Wild type | None | +a | 430 ± 15 |
| −b | 460 ± 20 | ||
| pBQ | + | 510 ± 35 | |
| − | 490 ± 30 | ||
| DMBQ | + | 470 ± 30 | |
| − | 450 ± 25 | ||
| DCBQ | + | 110 ± 15 | |
| − | 130 ± 20 | ||
| Mutant | None | + | 420 ± 20 |
| − | 250 ± 10 | ||
| pBQ | + | 410 ± 30 | |
| − | 0 | ||
| DMBQ | + | 440 ± 25 | |
| − | 0 | ||
| DCBQ | + | 100 ± 10 | |
| − | 0 |
Intact cells were treated for 5 min in darkness and oxygen evolution was measured at saturating light intensity in the presence of 0.5 mm K3Fe(CN)6 with or without 1 mm quinone. The temperature of measurements was 30°C. Each value represents the average and sd from three independent measurements.
a
Cells were grown in the presence of 20 μm.
b
Cells grown in the presence of PG were transferred to medium without PG and grown for 5 d.