To investigate the effects of sulfite on the chloroplast development, etiolated barley seedlings were treated with 100 mM sulfite solution every 3 hour by spraying during 96 hours greening period. The effects were determined by chlorophyll a, b and carotenoids contents, photosynthetic electron transport activity, chlorophyll fluorescence yield and fluorescence quenching parameters.
The contents of chlorophyll a and carotenoids were decreased than that of control by treatment of sulfite over 48 hours greening. PS Ⅱ is more sensitive to sulfite than PS I is. And by the addition of DPC to the chloroplasts of the barley seedling treated with sulfite, the photoreduction of DCPIP was not recovered. In greening with sulfite treated barley leaves, Fo, Fv and Fv/Fm ratio were decreased with little difference from that of control. But qP, qNP and qR were lowed in comparison with those of controls whereas qE was slightly higher than that of control. Especially, it is interesting that qR was decreased markedly compared to that of control. The results in the change of PS I activity, Fv/Fm and qP suggest that the site of inhibition by sulfite is carbon dioxide reduction cycle.