Main content area

Effect of green light on the amount and activity of NDH-1–PSI supercomplex in Synechocystis sp. strain PCC 6803

Gao, F., Ogawa, T., Ma, W.
Photosynthetica 2018 v.56 no.1 pp. 316-321
Synechocystis sp. PCC 6803, electron transfer, gel electrophoresis, green light, red light, thylakoids
Cyanobacterial NDH-1 interacts with PSI to form NDH-1–PSI supercomplex. CpcG2, a linker protein for the PSI-specific peripheral antenna CpcG2-phycobilisome, is essential for stabilization of the supercomplex. Green light (GL) increased the expression of CpcG2 but had little effect, if any, on the expression of NDH-1 and PSI, when compared to the abundance of these components under red light (RL). The increased expression of CpcG2 intensified the band of NDH-1–PSI supercomplex after blue-native gel electrophoresis of the thylakoid membrane, possibly by stabilizing the supercomplex. The activity of NDH-1-dependent cyclic electron transport around PSI increased when cells grown under RL were transferred to a low intensity GL but was suppressed when cells were grown under high intensities of GL. The functionality of PSI showed the same trend. We thus conclude that GL increases the expression of CpcG2, thereby increasing the abundance of the NDH-1–PSI supercomplex and its activity at low GL but not at higher GL.