Reports

Red and Far-Red Light Effects on a Short-Term Behavioral Response of a Dimoflagellate

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Science  06 Sep 1968:
Vol. 161, Issue 3845, pp. 1028-1029
DOI: 10.1126/science.161.3845.1028

Abstract

Cessation of movement (stop response) is used as a criterion for light reception by the dinoflagellate Gyrodinium dorsum Kofoid. Brief irradiation (2 seconds at 470 nanometers) elicits a stop response in cells any time during the 6-minute interval after removal from growth lights. This stop response is inactivated by exposure for 4 minutes to 470-nanometer light prior to stimulation. Red light (620 nanometers) reactivates this stop response, and far-red light (700 nanometers) reverses this reactivation. This red-far-red photo reversibility is taken as evidence for phytochrome involvement.