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Lettuce Seed Germination: Evidence for a Reversible Light-Induced Increase in Growth Potential and for Phytochrome Mediation of the Low Temperature Effect.
TLDR
It has been proposed that promotion by gibberellic acid an(l kinefin is effecte(d via (lifferent mechanlisms, neither of which is the samiie as that for l)rolllotion l)y R, to eluicidlate the germination-prolimotinig effect of low templerature.
Action Spectra for Chromatic Adaptation in Tolypothrix tenuis.
TLDR
Chromatic adaptation and another photomorphogenic response in the blue-green algae are discussed in terms of possible regulation by a photoreversible pigment recently isolated from Tolypothrix.
Photoreversible Pigment: Occurrence in a Blue-Green Alga
A new photoreversible pigment has been isolated from the blue-green alga Tolypothrix tenuis. This pigment bears certain resemblances to phytochrome, except that absorption maxima for the two forms
Action spectra for chromatic adaptation in the blue-green alga Fremyella diplosiphon
TLDR
These results contrast strongly with previous determinations in the same organism, with major activity indicated in the blue; they are consistent with the control of photomorphogenesis in the Cyanophyta by a master pigment, analogous to phytochrome.
Cultivation in the Dark of the Blue‐green Alga Fremyella diplosiphon. A Photoreversible Effect of Green and Red Light on Growth Rate
TLDR
The blue-green alga Fremyella diplosiphon Drouet can be grown in the dark on a medium consisting of mineral salts, glucose, and casein hydrolysate and the effect of green is reversible by brief irradiation with red light, and multiple photoreversibility was demonstrated.
LETTUCE SEED GERMINATION: EFFECTS OF HIGH TEMPERATURE AND OF REPEATED FAR‐RED TREATMENT IN RELATION TO PHYTOCHROME
  • J. Scheibe, A. Lang
  • Environmental Science
    Photochemistry and photobiology
  • 1 February 1969
TLDR
At 37°C the active form of phytochrome in lettuce seed cannot function to promote subsequent germination, and this effect of high temperature is distinct from thermal acceleration of dark reversion from the active shape to the inactive form, and may be due to reversible denaturation of phYtochrome.
An action spectrum in the blue for inhibition of germination of lettuce seed
TLDR
Using a 2-h irradiation period at constant quantum irradiance, a complete action spectrum for inhibition of germination of lettuce seed has been obtained and it was shown that phytochrome potentiation of Germination is maximal at all wavelengths below 700 nm, including the highly active blue region.
Lettuce seed germination: A phytochrome-mediated increase in the growth rate of lettuce seed radicles
TLDR
If the growing half-seeds were classified into proportions of the sample that had undergone a growth increment greater than a certain, selected value, growth rate was found to be enhanced by red light and this enhancement paralleled the phytochrome-mediated increase in the rate of appearance of a geotropic curvature in seed axes.
Studies on photoblastic germination in lettuce seed
TLDR
It was shown, with the aid of osmotic inhibition of germination, that the action of the far-red-absorbing form of phytochrome (Pf) in promoting germination can be completed even if the seed is held under conditions where germination is not possible, and that low temperatures act by delaying or preventing transformation of Pf.
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