title: Microamperometric estimation of photosynthesis inhibition in a single algal protoplast.
abstract: The single-cell level inhibition of photosynthesis by some chemicals was investigated from the light-irradiation induced response of intracellular oxygen reduction current at an ultramicroelectrode inserted into a single algal protoplast. The addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an electron-transport inhibitor, decreased a current peak appeared immediately after the light irradiation. The pI50 value (the negative decadic logarithm of the concentration needed for 50% inhibition) was determined from the change in response patterns and found to be 6.9 for DCMU. 2,4-Dichlorophenoxyacetic acid (2,4-D), an auxin herbicide, showed no effect on photosynthesis in the effective concentration range. 2,4-Dinitrophenol (DNP), a proton carrier, accelerated the oxygen production upon light irradiation.
authors.affiliation: Department of Molecular Chemistry and Engineering, Faculty of Engineering, Tohoku University, Sendai, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsue
authors.forename: S
authors.initials: S
authors.lastname: Koike
authors.forename: I
authors.initials: I
authors.lastname: Uchida
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology; D019297:2,4-Dinitrophenol; D000460:Chlorophyta / Q000378:metabolism*; D004140:Dinitrophenols / Q000494:pharmacology; D004237:Diuron / Q000494:pharmacology; D004563:Electrochemistry / Q000379:methods; D007700:Kinetics; D008832:Microchemistry; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D011523:Protoplasts / Q000187:drug effects / Q000378:metabolism*; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D004140:Dinitrophenols; D014475:Uncoupling Agents; D015084:2,4-Dichlorophenoxyacetic Acid; D004237:Diuron; D019297:2,4-Dinitrophenol; D010100:Oxygen