Fluorescence Induction Characteristics of Wild-Type and Herbicide-Resistant Strain of the Photosynthetic Bacterium Rhodobacter capsulatus
نویسندگان
چکیده
Fluorescence induction characteristics have been studied in wild-type and atrazine-resistant mutant o f Rhodobacter capsulatus. Fluorescence induction was found to be a useful technique to monitor the altered electron transfer in the atrazine-resistant mutants as well as in the differ ent membrane fractions o f wild-type R. capsulatus. In both cases, the proportion o f the fast rise o f variable fluorescence was increased indicating the enhancement o f QA. In the mutant strain, the / 50 value o f triazine herbicide terbutryn was increased by 1 0 0 -fold whereas the natu ral resistance o f R. capsulatus against diuron was abolished by the mutation.
منابع مشابه
Analysis of the fnrL gene and its function in Rhodobacter capsulatus.
The fnr gene encodes a regulatory protein involved in the response to oxygen in a variety of bacterial genera. For example, it was previously shown that the anoxygenic, photosynthetic bacterium Rhodobacter sphaeroides requires the fnrL gene for growth under anaerobic, photosynthetic conditions. Additionally, the FnrL protein in R. sphaeroides is required for anaerobic growth in the dark with an...
متن کاملShort-term regulation of nitrogenase activity by NH4+ in Rhodobacter capsulatus: multiple in vivo nitrogenase responses to NH4+ addition.
The photosynthetic bacterium Rhodobacter capsulatus has been shown to carry out nitrogenase "switch-off," a rapid, reversible inhibition of in vivo activity. Here, we demonstrate that highly nitrogen-limited cultures of both the wild-type strain and a draT draG mutant are capable of nitrogenase switch-off while moderately nitrogen-limited cultures show instead a "magnitude" response, with a dec...
متن کاملDraft Genome Sequences of Two Heat-Resistant Mutant Strains (A52 and B41) of the Photosynthetic Hydrogen-Producing Bacterium Rhodobacter capsulatus
The draft genome sequences of two heat-resistant mutant strains, A52 and B41, derived from Rhodobacter capsulatus DSM 1710, and with different hydrogen production levels, are reported here. These sequences may help understand the molecular basis of heat resistance and hydrogen production in R. capsulatus.
متن کاملRegA Protein from Rhodobacter capsulatus 235 DNA Binding of Wild Type RegA Protein and Its Differential Effect on the Expresion of Pigment Binding Proteins in Rhodobacter capsulatus
The transcription of genes encoding pigment binding proteins in the facultative photosynthetic bacterium Rhodobacter capsulatus is regulated in response to oxygen partial pressure. Previous results identified RegA and RegB as members of a two component system involved in oxygen dependent synthesis of the photosynthetic apparatus. Here we demonstrate that RegA differentially controls the transcr...
متن کاملThioredoxin 2 is involved in oxidative stress defence and redox-dependent expression of photosynthesis genes in Rhodobacter capsulatus.
Thioredoxins are small ubiquitous proteins that display different functions mainly via redox-mediated processes. The facultatively photosynthetic bacterium Rhodobacter capsulatus harbours at least two genes for thioredoxin 1 and 2, trxA and trxC. It is demonstrated that thioredoxin 2 of R. capsulatus can partially replace the thioredoxin 1 function as a hydrogen donor for methionine sulfoxide r...
متن کامل