Vlfr
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Alcalóides de Psychotria : fotorregulação e propriedades antioxidantes e antimutagênicas
Espécies de Psychotria encontradas no sul do Brasil produzem alcalóides do tipo monoterpeno indólicos, alguns deles com interessantes atividades biológicas e oriundos de novas rotas biossintéticas. P. leiocarpa Cham. & Schlecht. acumula N, b-D-glicopiranosilvincosamida (GPV), o primeiro alcalóide N-glicosilado desta classe a ser descrito. O extrato con
Publicado em: 2007
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2. Brassinosteroid Mutants Uncover Fine Tuning of Phytochrome Signaling1
Phytochromes (phy) A and B provide higher plants the ability to perceive divergent light signals. phyB mediates red/far-red light reversible, low fluence responses (LFR). phyA mediates both very-low-fluence responses (VLFR), which saturate with single or infrequent light pulses of very low fluence, and high irradiance responses (HIR), which require sustained
American Society of Plant Physiologists.
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3. Fluence-Response Curves and Action Spectra for the Very Low Fluence and the Low Fluence Response for the Induction of Kalanchoë Seed Germination 1
Germination of Kalanchoë blossfeldiana Poelln. seeds is absolutely light-requiring. Germination of one seed is the result of one out of three reactions, viz. the very low fluence response (VLFR), the low fluence response (LFR) and the high fluence response/high irradiance response. In order to demonstrate the involvement of phytochrome for both photorespons
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4. OWL1: An Arabidopsis J-Domain Protein Involved in Perception of Very Low Light Fluences[W]
To sense ambient light conditions in order to optimize their growth and development, plants employ a battery of photoreceptors responsive to light quality and quantity. Essential for the sensing of red and far-red (FR) light is the phytochrome family of photoreceptors. Among them, phytochrome A is special because it mediates responses to different light cond
American Society of Plant Biologists.
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5. The Serine-Rich N-Terminal Domain of Oat Phytochrome A Helps Regulate Light Responses and Subnuclear Localization of the Photoreceptor1
Phytochrome (phy) A mediates two distinct photobiological responses in plants: the very-low-fluence response (VLFR), which can be saturated by short pulses of very-low-fluence light, and the high-irradiance response (HIR), which requires prolonged irradiation with higher fluences of far-red light (FR). To investigate whether the VLFR and HIR involve differen
American Society of Plant Physiologists.
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6. Phytochrome A Mediates the Promotion of Seed Germination by Very Low Fluences of Light and Canopy Shade Light in Arabidopsis.
Seeds of the wild type (WT) and of the phyA and phyB mutants of Arabidopsis thaliana were exposed to single red light (R)/far-red light (FR) pulses predicted to establish a series of calculated phytochrome photoequilibria (Pfr/P). WT and phyB seeds showed biphasic responses to Pfr/P. The first phase, i.e. the very-low-fluence response (VLFR), occurred below
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7. A Growth Regulatory Loop That Provides Homeostasis to Phytochrome A SignalingW⃞
Phytochrome kinase substrate1 (PKS1) is a cytoplasmic protein that interacts physically with, and is phosphorylated by, the plant photoreceptor phytochrome. Here, we show that light transiently increases PKS1 mRNA levels and concentrates its expression to the elongation zone of the hypocotyl and root. This response is mediated by phytochrome A (phyA) acting
American Society of Plant Biologists.
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8. Missense Mutation in the PAS2 Domain of Phytochrome A Impairs Subnuclear Localization and a Subset of Responses
Phytochrome A signaling shows two photobiologically discrete outputs: so-called very-low-fluence responses (VLFR) and high-irradiance responses (HIR). By modifying previous screening protocols, we isolated two Arabidopsis mutants retaining VLFR and lacking HIR. Phytochrome A negatively or positively regulates phytochrome B signaling, depending on light condi
American Society of Plant Biologists.
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9. fhy3-1 Retains Inductive Responses of Phytochrome A1
The fhy3 mutation of Arabidopsis impairs phytochrome A (phyA)-mediated inhibition of hypocotyl growth without affecting the levels of phyA measured spectrophotometrically or immunochemically. We investigated whether the fhy3-1 mutation has similar effects on very low fluence responses (VLFR) and high irradiance responses (HIR) of phyA. When exposed to hourly
American Society of Plant Physiologists.
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10. Sustained but Not Transient Phytochrome A Signaling Targets a Region of an Lhcb1*2 Promoter Not Necessary for Phytochrome B Action
Current evidence is inconclusive regarding the point of signaling convergence downstream from different members of the phytochrome family. In transgenic Arabidopsis, the activity of a reporter enzyme under the control of the −453 to +67 fragment of an Lhcb1*2 promoter shows very low fluence responses (VLFRs) and high-irradiance responses (HIRs) mediated by
American Society of Plant Physiologists.