PhotockrinrAtry aiid Photobrology. 1975. Vol 22. pp 75 76
Pergamon Press
Printed in Great Britain
RESEARCH NOTE TEMPERATURE DEPENDENCE OF THE FLUORESCENCE QUANTUM YIELD OF PHYTOCHROME PILL-SOONSONG*,QUAECHAE*,and WINSLOWR. BRIGGS~
* Department of Chemistry, Texas Tech University, Lubbock, Texas 79409 and t Carnegie Institution of Washington, Stanford, California 94305, U.S.A. (Received 20 January 1975; accepted 28 March 1975)
INTRODUCTION
Phytochrome (P,) undergoes phototransformation to the P,, form upon irradiation at 660 nm. This phototransformation is known to trigger a number of photomorphogenic responses in plants, including flowering, seed germination, photomimetic effects, and other control mechanisms of vegetative growth. Recently, a successful isolation and purification of ‘large’ phytochrome (PJ,which retains its apoprotein undegraded (Tobin and Briggs, 1973), has been performed. This phytochrome exhibits characteristic features such as the lack of fluorescence at room temperature (Song et al., 1973). In this note, we report on the temperature dependence of the fluorescence quantum yield of this P, preparation.
-
Table 1. Fluorescence quantum yields of P, in 10% glycerol (v/v) in water as a function of temperature T
630
Aex‘u38hd
I(*
.*
f
W.040’
*0.038 .I
0.016
0.039
0.038
0.015
0.039
0.038
0.011
0.011
0.031
0.031
150
0.010
0.010
0.028
0.029
200
0.010
0.011
0.028
0.030
250
0.005
0.005
0.014
0.016
298
-4
‘10
-4 < 10
‘10
14
“4.015‘
*0.014
50
0.016
77
0.01s
100
-4
Pergamon Press
Printed in Great Britain
RESEARCH NOTE TEMPERATURE DEPENDENCE OF THE FLUORESCENCE QUANTUM YIELD OF PHYTOCHROME PILL-SOONSONG*,QUAECHAE*,and WINSLOWR. BRIGGS~
* Department of Chemistry, Texas Tech University, Lubbock, Texas 79409 and t Carnegie Institution of Washington, Stanford, California 94305, U.S.A. (Received 20 January 1975; accepted 28 March 1975)
INTRODUCTION
Phytochrome (P,) undergoes phototransformation to the P,, form upon irradiation at 660 nm. This phototransformation is known to trigger a number of photomorphogenic responses in plants, including flowering, seed germination, photomimetic effects, and other control mechanisms of vegetative growth. Recently, a successful isolation and purification of ‘large’ phytochrome (PJ,which retains its apoprotein undegraded (Tobin and Briggs, 1973), has been performed. This phytochrome exhibits characteristic features such as the lack of fluorescence at room temperature (Song et al., 1973). In this note, we report on the temperature dependence of the fluorescence quantum yield of this P, preparation.
-
Table 1. Fluorescence quantum yields of P, in 10% glycerol (v/v) in water as a function of temperature T
630
Aex‘u38hd
I(*
.*
f
W.040’
*0.038 .I
0.016
0.039
0.038
0.015
0.039
0.038
0.011
0.011
0.031
0.031
150
0.010
0.010
0.028
0.029
200
0.010
0.011
0.028
0.030
250
0.005
0.005
0.014
0.016
298
-4
‘10
-4 < 10
‘10
14
“4.015‘
*0.014
50
0.016
77
0.01s
100
-4
