Mutations of Cytochrome b559 and PsbJ on and near the QC Site in Photosystem II Influence the Regulation of Short-Term Light Response and Photosynthetic Growth of the Cyanobacterium Synechocystis sp. PCC 6803
Huang, Jine Yung; Chiu, Yi Fang; Ortega Rodríguez, José María; Wang, Hsing Ting; Tseng, Tien Sheng; Ke, Shyue Chu; Roncel Gil, Mercedes; Chu, Hsiu An
- Published
- 2016
- Publisher
- American Chemical Society
- Language
- en
Abstract
The characteristic features of two types of short-term light adaptations of the photosynthetic apparatus of the cyanobacterium Synechocystis sp. PCC 6803, state transition and blue-green light-induced fluorescence quenching, were compared in wild-type and cytochrome b559 and PsbJ mutant cells with mutations on and near the QC site in photosystem II (PSII). All mutant cells grew photoautotrophically and assembled stable PSII. Thermoluminescence emission experiments showed a decrease in the stability of the S3QB-/S2QB- charge pairs in the A16FJ, S28Aβ, and V32Fβ mutant cells. When dark-adapted wild-type and mutant cells were illuminated by medium-intensity blue light, the increase in the PSII fluorescence yield (indicating a transition to state 1) was more prominent in mutant than wild-type cells. Strong blue-light conditions induced a quenching of fluorescence corresponding to nonphotochemical fluorescence quenching (NPQ). The extension of NPQ decreased significantly in the mutants, and the kinetics appeared to be affected. When similar measures were repeated on an orange carotenoid protein (OCP)-deficient background, little or no quenching was observed, which confirms that the decrease in fluorescence under strong blue light corresponded to the OCP-dependent NPQ. Immunoblot results showed that the attenuated effect of blue light-induced NPQ in mutant cells was not due to a lack of OCP. Photosynthetic growth and biomass production were greater for A16FJ, S28Aβ, and V32Fβ mutant cells than for wild-type cells under normal growth conditions. Our results suggest that mutations of cytochrome b559 and PsbJ on and near the QC site of PSII may modulate the short-term light response in cyanobacteria.
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Figure 1.
Figure 2. 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) A16FJ B FM,dark AL on AL off F0 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) WT AL on AL off F M,dark A F 0 0100 200 300 400 500 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 Fluorescence Time (seconds) G19FJ F F m,dark F 0 AL on AL off 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) S23Aα E AL on AL off F 0 F M,dark 0100 200 300 400 500 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 0.34 Fluorescence Time (seconds) AL on AL off DV32Fβ F M,dark F 0 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) AL on AL off F M,dark C F 0 S28Aβ
Figure 3 0100 200 300 400 500 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 Fluorescence Time (seconds) AL on AL off F0 FM,dark BA16FJ strong blue AL 0100 200 300 400 500 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) AL on AL off F0 DV32Fβ FM,dark strong blue AL 0100 200 300 400 500 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 Fluorescence Time (seconds) WT strong blue AL AL on AL off F M,dark F 0 A 0100 200 300 400 500 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 Fluorescence Time (seconds) AL on AL off C FM,dark S28Aβ strong blue AL F0 0100 200 300 400 500 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 Fluorescence Time (seconds) G19FJ strong blue AL F F m,dark F 0 AL on AL off 0100 200 300 400 500 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 Fluorescence Time (seconds) S23Aα E F M,dark strong blue AL AL on AL off F 0
Figure 4 0100 200 300 400 500 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 WT A16FJ S28Aβ V32Fβ NPQ Time (seconds) Blue AL on Blue AL off
Figure 5 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) ∆OCP/WT A F m,dark F 0 AL on AL off 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 ∆OCP/A16FJ Fluorescence Time (seconds) F m,dark B F 0 AL on AL off 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 ∆OCP/WT Fluorescence Time (seconds) F 0 F m,dark E AL on AL off strong blue light 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) ∆OCP/A16FJ F 0 AL on AL off F F m,dark strong blue light 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 ∆OCP/S28Aβ Fluorescence Time (seconds) strong blue light F m,dark G F 0 AL on AL off 0100 200 300 400 500 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 0.34 ∆OCP/V32Fβ Fluorescence Time (seconds) D F m,dark F 0 AL on AL off 0100 200 300 400 500 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 Fluorescence Time (seconds) ∆OCP/S28Aβ C F m,dark F 0 AL on AL off 0100 200 300 400 500 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 0.34 ∆OCP/V32Fβ Fluorescence Time (seconds) strong blue light H Fm,dark F0AL on AL off
Figure 6. 010 20 30 40 50 60 70 WT B2 B1 Temperature (°C) TL intensity (a.u.) 010 20 30 40 50 60 70 A16FJ B2 B1 Temperature (°C) TL intensity (a.u.) 010 20 30 40 50 60 70 S28Aβ B1 B2 Temperature (°C) TL intensity (a.u.) V32Fβ B2 B1 Temperature (°C) TL intensity (a.u.)
Figure 7 400 450 500 550 600 650 700 750 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Absorbance Wavelength (nm) WT A16FJ S28Aβ V32Fβ 635 685
Figure 8.
Figure 9. 0 20 40 60 80 100 120 S28Aβ WT Relative abundance (%) A16FJ PQ PQH2 V32Fβ
