Action spectrum for subliminal light control of adaptation in Phycomyces phototropism.

X. Y. Chen, Y. Q. Xiong, E. D. Lipson

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Adaptation processes enable phototropism and other blue light responses of Phycomyces to operate over a 10-decade range of fluence rate. Phototropic latency, used routinely to monitor the kinetics of sensitivity recovery after a step down in fluence rate, can be shortened by application of dim light for 35 min during the early part of the latency period. This light is termed subliminal, because it does not elicit phototropism under these experimental conditions; rather, it exerts its influence on the underlying adaptation kinetics. Fluence rate-response data for this latency reduction, obtained at 17 wavelengths of subliminal light from 347 to 742 nm, showed a variety of shapes that could be fit by zero, one, or two sigmoidal components, plus a constant term. At most wavelengths, the fluence-rate threshold for latency reduction by subliminal light tended to be well below the absolute threshold for phototropism, indicating that this effect is highly sensitive. An action spectrum for the sensitivity of the subliminal light effect, derived from the fluence rate-response curves, shows major peaks around 400 and 500 nm and a broad band from 570 to 670 nm, followed by a steep absorption edge. The sensitivity in the near ultraviolet region is relatively very low. The magnitude of the latency reduction also depends strongly on wavelength with a maximum at about 450 nm. The fluence-rate response data and the action spectrum--which is markedly different from that for phototropism and other blue-light responses of Phycomyces--indicate the participation of multiple pigments, or pigment states, in the photocontrol of adaptation.

Original languageEnglish (US)
Pages (from-to)425-431
Number of pages7
JournalPhotochemistry and Photobiology
Volume58
Issue number3
StatePublished - Sep 1993

Fingerprint

phototropism
Phototropism
Phycomyces
Ocular Adaptation
fluence
Light
pigments
Pigments
Wavelength
sensitivity
Photophobia
wavelengths
Kinetics
thresholds
kinetics
Reaction Time
Action Spectrum
recovery
broadband
Recovery

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biophysics

Cite this

Action spectrum for subliminal light control of adaptation in Phycomyces phototropism. / Chen, X. Y.; Xiong, Y. Q.; Lipson, E. D.

In: Photochemistry and Photobiology, Vol. 58, No. 3, 09.1993, p. 425-431.

Research output: Contribution to journalArticle

Chen, X. Y. ; Xiong, Y. Q. ; Lipson, E. D. / Action spectrum for subliminal light control of adaptation in Phycomyces phototropism. In: Photochemistry and Photobiology. 1993 ; Vol. 58, No. 3. pp. 425-431.
@article{11027b63f2a846eb94e7e71f7f5c7277,
title = "Action spectrum for subliminal light control of adaptation in Phycomyces phototropism.",
abstract = "Adaptation processes enable phototropism and other blue light responses of Phycomyces to operate over a 10-decade range of fluence rate. Phototropic latency, used routinely to monitor the kinetics of sensitivity recovery after a step down in fluence rate, can be shortened by application of dim light for 35 min during the early part of the latency period. This light is termed subliminal, because it does not elicit phototropism under these experimental conditions; rather, it exerts its influence on the underlying adaptation kinetics. Fluence rate-response data for this latency reduction, obtained at 17 wavelengths of subliminal light from 347 to 742 nm, showed a variety of shapes that could be fit by zero, one, or two sigmoidal components, plus a constant term. At most wavelengths, the fluence-rate threshold for latency reduction by subliminal light tended to be well below the absolute threshold for phototropism, indicating that this effect is highly sensitive. An action spectrum for the sensitivity of the subliminal light effect, derived from the fluence rate-response curves, shows major peaks around 400 and 500 nm and a broad band from 570 to 670 nm, followed by a steep absorption edge. The sensitivity in the near ultraviolet region is relatively very low. The magnitude of the latency reduction also depends strongly on wavelength with a maximum at about 450 nm. The fluence-rate response data and the action spectrum--which is markedly different from that for phototropism and other blue-light responses of Phycomyces--indicate the participation of multiple pigments, or pigment states, in the photocontrol of adaptation.",
author = "Chen, {X. Y.} and Xiong, {Y. Q.} and Lipson, {E. D.}",
year = "1993",
month = "9",
language = "English (US)",
volume = "58",
pages = "425--431",
journal = "Photochemistry and Photobiology",
issn = "0031-8655",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Action spectrum for subliminal light control of adaptation in Phycomyces phototropism.

AU - Chen, X. Y.

AU - Xiong, Y. Q.

AU - Lipson, E. D.

PY - 1993/9

Y1 - 1993/9

N2 - Adaptation processes enable phototropism and other blue light responses of Phycomyces to operate over a 10-decade range of fluence rate. Phototropic latency, used routinely to monitor the kinetics of sensitivity recovery after a step down in fluence rate, can be shortened by application of dim light for 35 min during the early part of the latency period. This light is termed subliminal, because it does not elicit phototropism under these experimental conditions; rather, it exerts its influence on the underlying adaptation kinetics. Fluence rate-response data for this latency reduction, obtained at 17 wavelengths of subliminal light from 347 to 742 nm, showed a variety of shapes that could be fit by zero, one, or two sigmoidal components, plus a constant term. At most wavelengths, the fluence-rate threshold for latency reduction by subliminal light tended to be well below the absolute threshold for phototropism, indicating that this effect is highly sensitive. An action spectrum for the sensitivity of the subliminal light effect, derived from the fluence rate-response curves, shows major peaks around 400 and 500 nm and a broad band from 570 to 670 nm, followed by a steep absorption edge. The sensitivity in the near ultraviolet region is relatively very low. The magnitude of the latency reduction also depends strongly on wavelength with a maximum at about 450 nm. The fluence-rate response data and the action spectrum--which is markedly different from that for phototropism and other blue-light responses of Phycomyces--indicate the participation of multiple pigments, or pigment states, in the photocontrol of adaptation.

AB - Adaptation processes enable phototropism and other blue light responses of Phycomyces to operate over a 10-decade range of fluence rate. Phototropic latency, used routinely to monitor the kinetics of sensitivity recovery after a step down in fluence rate, can be shortened by application of dim light for 35 min during the early part of the latency period. This light is termed subliminal, because it does not elicit phototropism under these experimental conditions; rather, it exerts its influence on the underlying adaptation kinetics. Fluence rate-response data for this latency reduction, obtained at 17 wavelengths of subliminal light from 347 to 742 nm, showed a variety of shapes that could be fit by zero, one, or two sigmoidal components, plus a constant term. At most wavelengths, the fluence-rate threshold for latency reduction by subliminal light tended to be well below the absolute threshold for phototropism, indicating that this effect is highly sensitive. An action spectrum for the sensitivity of the subliminal light effect, derived from the fluence rate-response curves, shows major peaks around 400 and 500 nm and a broad band from 570 to 670 nm, followed by a steep absorption edge. The sensitivity in the near ultraviolet region is relatively very low. The magnitude of the latency reduction also depends strongly on wavelength with a maximum at about 450 nm. The fluence-rate response data and the action spectrum--which is markedly different from that for phototropism and other blue-light responses of Phycomyces--indicate the participation of multiple pigments, or pigment states, in the photocontrol of adaptation.

UR - http://www.scopus.com/inward/record.url?scp=0027669971&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027669971&partnerID=8YFLogxK

M3 - Article

C2 - 8234478

AN - SCOPUS:0027669971

VL - 58

SP - 425

EP - 431

JO - Photochemistry and Photobiology

JF - Photochemistry and Photobiology

SN - 0031-8655

IS - 3

ER -