The light saturated rate of photosystem I-dependent electron transport (ascorbate/dichlorophenol-indophenol --> methyl vilogen in presence of 1 micromolar 3-[3,4-dichlorophenyl]-1,1-dimethyl urea [DCMU]) was increased by a high concentration of DCMU added to broken and uncoupled chloroplasts isolated from pea (Pisum sativum). At 50 micromolar DCMU, the increase was around 50%. No stimulation wa...

To understand the mechanism of photosynthetic inhibition and generation of reactive oxygen species (ROS) in Symbiodinium types under stress, chemicals such as dichlorophenyl dimethylurea (DCMU) are widely used. Moreover, DCMU and recently menthol were used to generate aposymbiotic cnidarian hosts. While the effects of DCMU on Symbiodinium cells have been extensively studied, no studies have sho...

approved: Redacted for Privacy (Norman I. Bishop) Three DCMU resistant mutants of the green alga Scenedesmus obliquus D3 are characterized. The mutants exhibit a ten fold greater resistance to DCMU than the wild type strain; this is comparable to the level of DCMU resistance detected in other DCMU resistant algae. In whole cell reactions, as well as isolated chloroplast reactions, the resistanc...

Mutations conferring herbicide resistance have been detected in two new strains (ZR250 and ZR480) of Euglena gracilis Z by partial gene cloning and sequencing. These mutants were originally derived from Z cells grown in medium containing progressively increasing concentrations of DCMU. Each of these strains have been characterized by measuring their growth kinetics, O2 evolution, and resistance...

The light-dependent Cl e uptake in Elodea densa exhibits dual DCMU inhibition curves dependent on the presence and absence of C02 . This suggests that cyclic photophosphorylation (energy surce in the absence of C02) is also inhibited by higher concentrations of DCMU in vivo. Further, at low DCMU concentrations the Cl0 uptake in the presence of C02 is much smaller than would be expected if cycli...

A selective chemical photosynthesis inhibitor, DCMU (Dichorophenyl-dimethylurea), dissolved in DMSO (Dimethyl sulfoxide) was substituted for the dark incubation method commonly used to measure the oxygen consumption in metabolic and primary production studies. We compared dxygen fluxes during light incubations with DCMU and dark incubations procedure, on soft bottom benthos. For this purpose, w...

In transgenic tobacco plants containing a pea ferredoxin transcribed region (Fed-1) driven by the cauliflower mosaic virus 35S promoter (P35S), light acts at a post-transcriptional level to control the abundance of Fed-1 mRNA in green leaves. To determine whether the light signal for this response involves photosynthesis, we treated transgenic seedlings with or without 3-(3,4-dichlorophenyl)-1,...

1. The percent inhibition of oxygen evolution by a given herbicide concentration is the same at various light intensities except at very low intensities where the percent inhibition becomes larger. The same results are obtained with the herbicide DCMU. 2. The concentration of DCMU causing 50% inhibition of oxygen evolution decreases with de­ creasing chloroplast (and thus of chlorophyll) concen...

Two-dimensional gel electrophoresis resolves total cellular protein from Euglena gracilis klebs var bacillaris Cori into 640 polypeptides, 79 of which are induced by light exposure. The inhibition of chloroplast translation by streptomycin, the direct inhibition of photosynthesis as well as the indirect inhibition of chlorophyll synthesis by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and th...

Iron-sufficient cells of the green alga Scenedesmus incrassatulus Bohl, R-83 released in the medium strong and weak Fe3+-complexing agents in response to freshly added Fe3+. Applied in the dark, photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) inhibited ferric reduction from ferric-EDTA or ferricyanide more than the chelator release. Fedeficient cells and DCMU-treated Fe-...