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THE USE OF A COMPUTERIZED SPECTRORADIOMETER TO PREDICT PHYTOCHROME PHOTOEQUILIBRIA UNDER POLYCHROMATIC IRRADIATION
Author(s) -
Gardner Gary,
Graceffo Michael A.
Publication year - 1982
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1982.tb04385.x
Subject(s) - phytochrome , spectroradiometer , etiolation , fluence , irradiation , photon , optics , physics , chemistry , analytical chemistry (journal) , biology , botany , nuclear magnetic resonance , chromatography , red light , reflectivity , nuclear physics , enzyme
A method is described for predicting the effect of polychromatic irradiation upon the photo‐stationary equilibrium of the plant photoreceptor phytochrome. This method follows from the rate equations for phototransformation and utilizes the in vivo action spectra for phytochrome phototransformation (Pratt and Briggs, 1966). A scanning spectroradiometer interfaced with a microcomputer is used to determine a spectral photon distribution from 360 to 800 nm. The products of the photon fluence rate and the relative quantum efficiencies at 2‐nm intervals are summed over the entire visible range to yield a predicted percentage of the pigment in the Pfr form. This value was determined under eight different polychromatic light sources and was generally within 7% Pfr of the value measured in etiolated corn coleoptiles under the same light sources.