Fig. 3.

Light saturation curves of oxygen evolution, ΦPSII and the effect of pgal in OTH95 (squares) and RCC809 (triangles) cells. (A) Oxygen evolution was monitored by using a Clark electrode under increasing light intensity, adjusted every 2 min. Photosynthetic activity was calculated as “net photosynthesis” (i.e., photosynthesis after correction for respiration) at any given light intensity. (B) ΦPSII, calculated as (Fm′ − Fs)/Fm′ (22). (C) Effect of pgal on both oxygen evolution and ΦPSII. Values are expressed as a percentage of change with respect to the untreated sample. Error bars indicate standard error of the mean of three independent measurements.