Light
Mostrando 1-12 de 20023 artigos, teses e dissertações.
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1. Close correspondence between the action spectra for the blue light responses of the guard cell and coleoptile chloroplasts, and the spectra for blue light-dependent stomatal opening and coleoptile phototropism.
Fluorescence spectroscopy was used to characterize blue light responses from chloroplasts of adaxial guard cells from Pima cotton (Gossypium barbadense) and coleoptile tips from corn (Zea mays). The chloroplast response to blue light was quantified by measurements of the blue light-induced enhancement of a red light-stimulated quenching of chlorophyll a fluo
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2. Light- and Carbon-Signaling Pathways. Modeling Circuits of Interactions1
Here, we report the systematic exploration and modeling of interactions between light and sugar signaling. The data set analyzed explores the interactions of sugar (sucrose) with distinct light qualities (white, blue, red, and far-red) used at different fluence rates (low or high) in etiolated seedlings and mature green plants. Boolean logic was used to
The American Society for Plant Biologists.
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3. Circadian Rhythms in Stomatal Responsiveness to Red and Blue Light.
Stomata of many plants have circadian rhythms in responsiveness to environmental cues as well as circadian rhythms in aperture. Stomatal responses to red light and blue light are mediated by photosynthetic photoreceptors; responses to blue light are additionally controlled by a specific blue-light photoreceptor. This paper describes circadian rhythmic aspect
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4. Chloroplast Distribution in Arabidopsis thaliana (L.) Depends on Light Conditions during Growth.
Chloroplasts of Arabidopsis thaliana move in response to blue light. Sensitivity to light and the range of fluence rates to which the chloroplasts respond were found to be comparable to those of other higher plants studied. We investigated typical chloroplast distributions in Arabidopsis grown under three different light conditions:standard-light conditions,
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5. Photoinduced Seed Germination of Oenothera biennis L: II. Analysis of the Photoinduction Period
The photoinduction period of Oenothera biennis L. seed germination was analyzed by varying the photoinduction temperature and by substituting red light pulses for continuous red light. At 24°C, seeds require 36 hours of continuous red light for maximal percent germination. The optimal photoinduction temperature is 32°C, with higher and lower temperatures b
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6. Dark Leaf Respiration in Light and Darkness of an Evergreen and a Deciduous Plant Species.
Dark respiration in light as well as in dark was estimated for attached leaves of an evergreen (Heteromeles arbutifolia Ait.) and a deciduous (Lepechinia fragans Greene) shrub species using an open gas-exchange system. Dark respiration in light was estimated by the Laisk method. Respiration rates in the dark were always higher than in the light, indicating t
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7. Blue light regulates the accumulation of two psbD-psbC transcripts in barley chloroplasts.
Synthesis of D2, a Photosystem II reaction center protein encoded by psbD, is differentially maintained during light-induced chloroplast maturation. The continued synthesis of D2 is paralleled by selective light-induced accumulation of two psbD-psbC transcripts which share a common 5' terminus. In the present study, we examine the nature of the photoreceptor
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8. Effects of blue and red light on expression of nuclear genes encoding chloroplast glyceraldehyde-3-phosphate dehydrogenase of Arabidopsis thaliana.
We have characterized the effects of different light spectra on expression of the nuclear genes (GapA and GapB) encoding chloroplast glyceraldehyde-3-phosphate dehydrogenase in Arabidopsis thaliana. Steady-state mRNA levels for both genes in etiolated seedlings increased after a short exposure to red or blue light. However, these increases could not be rever
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9. Light Control of Arabidopsis Development Entails Coordinated Regulation of Genome Expression and Cellular PathwaysW⃞
An expressed sequence tag–based microarray was used to profile genome expression underlying light control of Arabidopsis development. Qualitatively similar gene expression profiles were observed among seedlings grown in different light qualities, including far-red, red, and blue light, which are mediated primarily by phytochrome A, phytochrome B, and the c
American Society of Plant Biologists.
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10. Control of the Photosynthetic Apparatus of Acetabularia mediterranea by Blue Light 1: Analysis by Light-Saturation Curves
During growth, Acetabularia mediterranea requires the action of blue light to maintain high rates of photosynthesis. In the present study, blue light-dependent alterations of the photosynthetic apparatus, which can be detected by analysis of light-saturation curves and by measurements of partial reactions of the photosynthetic electron transport chain, are d
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11. Blue Light and Phytochrome-Mediated Stomatal Opening in the npq1 and phot1 phot2 Mutants of Arabidopsis1
Recent studies have shown that blue light-specific stomatal opening is reversed by green light and that far-red light can be used to probe phytochrome-dependent stomatal movements. Here, blue-green reversibility and far-red light were used to probe the stomatal responses of the npq1 mutant and the phot1 phot2 double mutant of Arabidopsis. In plants grown at
The American Society for Plant Biologists.
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12. Blue Light Interference in the Phytochrome-controlled Germination of the Spores of Cheilanthes farinosa1
Short exposure of the spores of Cheilanthes farinosa to low intensity red light promotes their germination, which is not reversed by a subsequent exposure to far red light. Germination is, however, inhibited by blue light administered before or after red light. Inhibition of germination by blue light is annulled by exposure to a higher intensity of red light