Abstract
Abstract— Membranous fractions obtained from dicotyledonous plants are rarely used to investigate light-induced absorbance changes indicative of the reduction of a fe-type cytochrome. Membrane fractions prepared by differential centrifugation from the inflorescence of cauliflower show the presence of a presumed flavin-cytochrome b complex with characteristics very similar to those described for the complex found in membrane preparations of corn coleoptiles. As for corn, the reduction of a cytochrome b, probably due to the photoexcitation of an endogenous flavin photoreceptor, is enhanced by adding riboflavin. Red light in the presence of methylene blue also caused the photoreduction of fr-type cyto-chrome(s). Solubilisation by TritonX–100 of the presumed flavin-cytochrome complex is possible without significant loss of photosensitizing capacity as for membrane preparations of corn. Salicylhydroxa-mic acid is a potent inhibitor of the cytochrome photoreduction in both monocotyledonar and dicotyle-donar systems. In contrast however to the corn system, addition of KCN influences the cytochrome photoreduction. This effect could indicate that for cauliflower, cytochromes belonging to the respiratory electron-chain are involved in the cytochrome photoreduction. Spectral studies demonstrate however specificity concerning the participation of cytochromes in the blue light induced absorbance changes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
