Photon trapping in photosystem II of photosynthesis. The fluorescence rise curve in the presence of 3-(3,4-dichlorophenyl)-1,1-dimetnhylurea.
Using isolated chloroplasts in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an analysis was made of the rise of the fluorescence yield effected by weak light. Depending on the pretreatment, the time-course of the rapid photochemical part of the rise varied between nearly first-order and quadratic kinetics, i.e., reflected either a one-quantum or a two-quantum conversion. We consider the occurrence of two photoreductants per system II unit, which are reoxidized in different dark reactions. The data further showed that the "first-order process" is also inhomogeneous.
D002736:Chloroplasts / Q000378:metabolism* / Q000528:radiation effects; D004237:Diuron / Q000494:pharmacology; D004735:Energy Transfer; D005453:Fluorescence; D006540:Herbicides / Q000494:pharmacology*; D007700:Kinetics; D008027:Light; D010788:Photosynthesis; D010945:Plants, Edible / Q000166:cytology; D011830:Radiation Effects; D014508:Urea / Q000494:pharmacology*
D006540:Herbicides; D014508:Urea; D004237:Diuron