Fluorescence and Photochemical Investigations of Phytochrome in Higher Plants
Figure 3
Raw (a, b), difference (c, d), and normalized (e, f) low-temperature (85 K) fluorescence emission spectra ( nm) of phytochrome in the tips of rice coleoptiles: in the initial etiolated state, when all the pigment is in its Pr form (curve 1), and after saturating red ( nm) illumination at 85 K converting part of Pr into the first photoproduct lumi-R stable at low temperature (Prlumi-R photoequilibrium) (curve 2); wild type (a, c, e); phyB mutant (b, d, f). The spectra of etiolated coleoptiles of the rice phyA and phyAphyB mutants (curve 3) are also given in (a) and (b), respectively. The spectra in (c) and (d) belonging to phyA are obtained by subtraction of curve 3 from curves 1 and 2 in (a) and (b), respectively, after their normalization at 660 nm to 1, where the emission of phytochrome is negligible. The spectra in (e, f) are the average phyA spectra obtained as in (c, d) of 3–6 different samples after their normalization in the maximum to 1. The spectra were not corrected for the spectral sensitivity of the fluorimeter. Bars SD. (From [22]).
