Fig. 9: High light treatment inhibited ATP synthase activity.
After S. viridis plants were treated with 4 h of control condition (ctrl_4h) or high light (HL_4h) or high temperature (HT_4h), photosynthetic parameters in treated leaves were monitored using the MultispeQ instrument. a ECSt, measured by electrochromic shift (ECS), representing the transthylakoid proton motive force, pmf. b Proton conductivity (ɡH+ = 1/τECS), proton permeability of the thylakoid membrane and largely dependent on the activity of ATP synthase, inversely proportional to the decay time constant of light–dark-transition-induced ECS signal (τECS). c Proton flux rates, vH+, calculated by ECSt/τECS, the initial decay rate of the ECS signal during the light–dark transition and proportional to proton efflux through ATP synthase to make ATP. d Non-photochemical quenching (NPQ) measured by MultispeQ. Mean ± SE, n = 3–6 biological replicates. Asterisk and pound symbols indicate statistically significant differences of ctrl_0h, HL_4h, and HT_4h compared to ctrl_4h using Student’s two-tailed t-test with unequal variance. (*0.01 < p < 0.05, #p < 0.01, the colors of * and # match the significance of the indicated conditions, yellow for HL_4h).
