Fluorescence induction used to measure parathion toxicity in the marine dinoflagellate Prorocentrum micans: a possible model for biodetection.

The marine dinoflagellate Prorocentrum micans Ehrenberg was used as a test organism to determine the conditions of use of fluorescence induction kinetic measurements in the study of parathion phytotoxicity. Measurements were taken of the kinetics of slow and fast fluorescence induction in whole cells and isolated chloroplast fragments at various concentrations of parathion. In both types of induction, the addition of parathion greatly decreased the fluorescence yield, indicating either inhibition of electron transport or physical changes. The action of parathion was a function of its concentration and was similar to the action of DCMU. Fluorescence induction was clearly less in isolated chloroplast fragments than in whole cells.