Figure 2.

Deletion of ndhV gene and its effect on NDH-CET. A, Construction of plasmid used to generate ndhV inactivation mutant (∆ndhV). B, PCR segregation analysis of the ∆ndhV mutant using the ndhV-E and ndhV-F primers (Supplemental Table S1). C, Western analysis of NdhV from total protein of the wild-type (WT) and ∆ndhV strains. Total protein corresponding to 1 µg Chl a was loaded onto each lane, and ATPβ was detected as a loading control. D, Monitoring of NDH-CET activity by Chl fluorescence. Experimental procedure as in Figure 1. a.u., Arbitrary units. E, Redox kinetics of P700 after termination of AL illumination (800 µmol photons m⁻² s⁻¹ for 30 s) under a background of FR light. The cells were illuminated by AL supplemented with FR light to store electrons in the cytoplasmic pool. After termination of AL illumination, P700⁺ was transiently reduced by electrons from the plastoquinone pool; thereafter, P700 was reoxidized by background FR light. The redox kinetics of P700 were recorded. The P700⁺ levels were standardized by their maximum levels attained by exposure to FR light. F, Kinetics of the P700⁺ rereduction in darkness after turning off FR light in the presence of 10 µm DCMU. The Chl a concentration was adjusted to 20 µg mL⁻¹ before measurement, and curves are normalized to the maximal signal.