Fig. 6

Photosynthetic parameters for PSII, a, c and e: under mFL after the addition of 1 min of bright light (dark yellow, 800 μmol photons m^− 2 s^− 1) to every 5 min of low light (white, 80 μmol photons m^− 2 s^− 1); and b, d and f: under sFL after the addition of 1 min of stronger light (bright yellow, 2000 μmol photons m^− 2 s^− 1) to every 5 min of low light (gray, 20 μmol photons m^− 2 s^− 1). The values shown are the means of at least three biological replicates. a and b: NPQ, non-photochemical quenching; c and d: Y(II), the actual conversion efficiency of light energy of PSII; e and f: 1 - qL, PQ redox state