Search Results
Results 351 - 400 of 1324
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Johnsson A - - 2009
In a microgravity experiment onboard the International Space Station, circumnutations of Arabidopsis thaliana were studied. Plants were cultivated on rotors under a light:dark (LD) cycle of 16 : 8 h, and it was possible to apply controlled centrifugation pulses. Time-lapse images of inflorescence stems (primary, primary axillary and lateral inflorescences) ...
Goggin Danica E - - 2009
Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ...
Kim Byung-Hoon - - 2009
Light is one of the most important environmental factors that regulate plant development. Here we report that a mutation in the Arabidopsis FIERY1 gene (FRY1) caused a shortened hypocotyl and shorter petioles, most dramatically under low-intensity red light and less pronounced under far-red and blue-light conditions. Furthermore, the fry1 mutant ...
Kurepin Leonid V - - 2008
The growth patterns of plants from alpine (sun) and prairie (shade) ecotypes of Stellaria longipes in response to change in light irradiance was investigated and involvement of cytokinins (CKs), auxin (IAA) and abscisic acid (ABA) was studied to examine the mechanism behind phenotypic plasticity of these plants in response to ...
Ho Chai-Ling - - 2009
Light regulates photosynthesis, growth and reproduction, yield and properties of phycocolloids, and starch contents in seaweeds. Despite its importance as an environmental cue that regulates many developmental, physiological, and biochemical processes, the network of genes involved during light deprivation are obscure. In this study, we profiled the transcriptome of Gracilaria ...
Simon Anne F AF Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110, - - 2009
Physiologic and pathogenic changes in amine release induce dramatic behavioral changes, but the underlying cellular mechanisms remain unclear. To investigate these adaptive processes, we have characterized mutations in the Drosophila vesicular monoamine transporter (dVMAT), which is required for the vesicular storage of dopamine, serotonin, and octopamine. dVMAT mutant larvae show ...
Chen Hao - - 2008
Seed dormancy offers plants an adaptive advantage that is crucial to their successful colonization of land. The decision to make the transition from a dormant seed to a photoautotrophic seedling is a result of a complex interaction of internal hormonal signals and external stimuli such as water, temperature and light. ...
Hayashi Eiji - - 2008
Temperature and light are primary environmental cues affecting seed germination. To elucidate the genetic architecture underlying lettuce (Lactuca sativa L.) seed germination under different environmental conditions, an F8 recombinant inbred line population consisting of 131 families was phenotyped for final germination and germination rate. Seeds were imbibed in water at ...
Brandt Sonja - - 2008
The red light-sensing photoreceptor FphA from Aspergillus nidulans is involved in the regulation of developmental processes in response to light. Here we present extended biochemical and spectroscopic characterization of recombinant FphA using a synthetic gene with host-adapted codon usage. The recombinant photosensory domain FphAN753 was shown to display all features ...
Demarsy Emilie - - 2009
Higher plants use several classes of blue light receptors to modulate a wide variety of physiological responses. Among them, both the phototropins and members of the Zeitlupe (ZTL) family use light oxygen voltage (LOV) photosensory domains. In Arabidopsis, these families comprise phot1, phot2 and ZTL, LOV Kelch Protein 2 (LKP2), ...
Singh Amoolya H - - 2009
The emerging coverage of diverse habitats by metagenomic shotgun data opens new avenues of discovering functional novelty using computational tools. Here, we apply three different concepts for predicting novel functions within light-mediated microbial pathways in five diverse environments. Using phylogenetic approaches, we discovered two novel deep-branching subfamilies of photolyases (involved ...
Han In-Seob - - 2008
It has been known for decades that red light pretreatment has complex effects on subsequent phototropic sensitivity of etiolated seedlings. Here, we demonstrate that brief pulses of red light given 2 h prior to phototropic induction by low fluence rates of blue light prevent the blue light-induced loss of green ...
Hu Jianping - - 2008
Peroxisomes are multifunctional organelles whose abundance and metabolic activities differ depending on the species, cell type, developmental stage and prevailing environmental conditions.1 However, little is known about the signaling pathways that control these variations, especially in plants. Our laboratory recently investigated the regulatory role of light in changes in peroxisome ...
Bhatia Shikha - - 2008
In our recent paper in Plant Physiology, we have reported the identification and functional characterization of a unique regulator, SHW1, a serine-arginine-aspartate rich protein in Arabidopsis seedling development.1 Genetic and molecular analyses have revealed that SHW1 functions in an independent and interdependent manner with COP1, and differentially regulates photomorphogenic growth ...
Fankhauser Christian - - 2008
To control many physiological responses, phytochromes directly modulate gene expression. A key regulatory event in this signal transduction pathway is the light-controlled translocation of the photoreceptor from the cytoplasm into the nucleus. Recent publications are beginning to shed light on the molecular mechanisms underlying this central control point. Interestingly, there ...
Siria A - - 2008
We report here for the first time the combination of x-ray synchrotron light and a micro-electro-mechanical system (MEMS). We show how it is possible to modulate in real time a MEMS mass distribution to induce a nanometric and tunable mechanical oscillation. The quantitative experimental demonstration we present here uses periodic ...
Losi A - - 2008
The growing number of sequenced prokaryotic genomes reveals a wide distribution of open reading frames (ORFs) that putatively encode for red- and blue light sensing photoreceptors. They comprise the bilin-binding phytochromes and the flavin-binding cryptochromes, LOV and BLUF proteins, indicating that about 1/4 of bacteria do possess at least one ...
Masuda Shinji - - 2008
PixD/Slr1694 from the cyanobacterium Synechocystis sp. PCC6803 is a member of a new class of flavin-containing blue-light sensory proteins containing a BLUF (blue light using flavin) domain. The photocycle reaction mechanism of BLUF is unique because only small structural changes of a bound chromophore are accompanied by a few hydrogen ...
Sasidharan Rashmi - - 2008
Shade avoidance in plants involves rapid shoot elongation to grow toward the light. Cell wall-modifying mechanisms are vital regulatory points for control of these elongation responses. Two protein families involved in cell wall modification are expansins and xyloglucan endotransglucosylase/hydrolases. We used an alpine and a prairie ecotype of Stellaria longipes ...
Datta Sourav - - 2008
B-box containing proteins play an important role in light signaling in plants. Here, we identify LIGHT-REGULATED ZINC FINGER1/SALT TOLERANCE HOMOLOG3 (STH3), a B-box encoding gene that genetically interacts with two key regulators of light signaling, ELONGATED HYPOCOTYL5 (HY5) and CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1). STH3 physically interacts with HY5 in vivo and ...
Li Lina - - 2008
RcaC is a large, complex response regulator that controls transcriptional responses to changes in ambient light color in the cyanobacterium Fremyella diplosiphon. The regulation of RcaC activity has been shown previously to require aspartate 51 and histidine 316, which appear to be phosphorylation sites that control the DNA binding activity ...
Girault Tiffanie - - 2008
Light controls bud burst in many plants, which subsequently affects their architecture. Nevertheless, very little is known about this photomorphogenic process. This study ascertains the effects of light on bud burst and on two of its components, i.e. growth of preformed leaves and meristem organogenesis in six cultivars from three ...
Hsiao Chi-Sheng - - 2008
A simple chemical solution process was used to prepare alumina nanoparticle-coated ZnO nanotubes (ANZTs). Transmission electron microscope (TEM) images proved that the alumina nanoparticles were uniformly dispersed on the ZnO nanotubes. After thermal treatment at different temperatures under various atmospheres, photoluminescence (PL) measurements showed that the ANZTs emitted a variety ...
Narikawa Rei - - 2008
Phytochromes and bacteriophytochromes in plants and some species of bacteria, respectively, are photoreceptors that bind linear tetrapyrroles and can respond to red and far-red light signals in a reversible manner. A related but distinct photoreceptor candidate, CikA (denoted ScCikA), has been reported to reset the circadian clock in the cyanobacterium ...
Wilson Adjélé - - 2008
Intense sunlight is dangerous for photosynthetic organisms. Cyanobacteria, like plants, protect themselves from light-induced stress by dissipating excess absorbed energy as heat. Recently, it was discovered that a soluble orange carotenoid protein, the OCP, is essential for this photoprotective mechanism. Here we show that the OCP is also a member ...
Laserna María Paula - - 2008
Dormancy is a complex trait finely regulated by hormones and environmental factors. The phytochromes that sense red:far-red (R:FR) are the sole photoreceptors involved in the termination of dormancy and the induction of germination by light. The aims of this study were to identify and characterize loci controlling this process in ...
Chen Meng - - 2008
In higher plants, one of the most striking effects of light at the cellular level is the formation of phytochrome nuclear bodies (PNBs). In Arabidopsis, two types of PNBs have been described: a transient type of PNBs (tPNBs), containing both phytochrome A and phytochrome B, observed during the dark-to-light transition ...
Kim Sang Yeol SY Department of Biology, Indiana University, Bloomington, Indiana 47405, - - 2008
In addition to pathways that regulate flowering in response to environmental signals such as photoperiod or cold temperatures (vernalization), flowering time is also regulated by light quality. In many species, far-red (FR) light is known to accelerate flowering. This is environmentally significant because leaves absorb more red light than FR ...
Hanaoka Mitsumasa - - 2008
In cyanobacteria, a series of genes are induced by, and cause tolerance to, high light stress conditions. Some of these genes share a short, repeated sequence motif known as a high light regulatory 1 (HLR1) element in their promoter regions. Previously, RpaB, a two-component response regulator, was shown to interact ...
Alabadí David - - 2008
After germination, seedlings follow one of two developmental programs, photo- and skotomorphogenesis, and the choice is determined by the interplay between environmental signals (light) and endogenous cues (the plant hormones gibberellins among others). In the December issue of Plant Journal we describe a molecular mechanism that allows the integration of ...
Hoang Nathalie - - 2008
Cryptochromes are a class of flavoprotein blue-light signaling receptors found in plants, animals, and humans that control plant development and the entrainment of circadian rhythms. In plant cryptochromes, light activation is proposed to result from photoreduction of a protein-bound flavin chromophore through intramolecular electron transfer. However, although similar in structure ...
Rivadossi Andrea - - 2008
The average, corrected attenuance spectra for both spectral forms of phytochrome in a mature leaf were calculated. Optical masking by chlorophyll together with the detour effect (optical path lengthening effect) due to multiple light scattering led to large changes in both the Qy band shape and wavelength position and the ...
Muleo Rosario - - 2008
This paper presents the results of the interaction of red light (R) with blue light (B), applied to shoots of M9 apple (Malus pumila paradisiaca Schmid) rootstock, on the regulation of stem growth, apical dominance and branching. These results are compared with the active form of phytochromes (PHYs) under monochromatic ...
Guo Lan - - 2008
Here, we analyzed the effects of light regulation on four selected histone modifications (H3K4me3, H3K9ac, H3K9me2, and H3K27me3) and the relationship of these histone modifications with the expression of representative light-regulated genes. We observed that the histone modifications examined and gene transcription were cooperatively regulated in response to changing light ...
Shen Hui - - 2008
The phytochrome (phy) family of photoreceptors regulates changes in gene expression in response to red/far-red light signals in part by physically interacting with constitutively nucleus-localized phy-interacting basic helix-loop-helix transcription factors (PIFs). Here, we show that PIF1, the member with the highest affinity for phys, is strongly sensitive to the quality ...
Gerhardt Karen E - - 2008
Flavonoid induction is regulated by complex signal transduction pathways involving cryptochrome, phytochrome and UVB photoreceptors. Previously, we identified the UVB-inducible flavonoids in Brassica napus cv. Topas leaves and showed that UVA affected accumulation of the quercetin (Q) and kaempferol (K) glycosides (Wilson et al. [2000] Photochem. Photobiol. 73, 678-684). In ...
Yu Xuhong - - 2008
Cryptochrome 2 (CRY2) is a blue/UV-A light receptor that regulates light inhibition of cell elongation and photoperiodic promotion of floral initiation in Arabidopsis. We and others have previously shown that CRY2 is a nuclear protein that regulates gene expression to affect plant development. We also showed that CRY2 is phosphorylated ...
Folta Kevin M - - 2008
Members of the 14-3-3 family of proteins participate in signal transduction by modulating flux through various pathways. Potential subfunctionalization within this family has produced a suite of related proteins with diverse client interactions and discrete localization. The associated study assesses the biological roles of two specific 14-3-3 isoforms, using genetic, ...
Malinovskaya S L - - 2008
The effect of helium-neon laser irradiation and wideband red light on electrical activity of open rat heart was examined after experimentally produced ischemia. The red light applied with the help of optical fibers modified parameters of cardiac electrical activity and intensity of lipid peroxidation in the myocardium. The effects of ...
Engler H - - 2008
Previous theoretical investigations on thermal flow in a horizontal fluid layer have shown that the critical temperature difference, where heat transfer changes from diffusion to convective flow, depends on the frequency of a time-modulated driving force. The driving force of thermal convection is the buoyancy force resulting from the interaction ...
Griebel Thomas - - 2008
We have examined molecular and physiological principles underlying the light dependency of defense activation in Arabidopsis (Arabidopsis thaliana) plants challenged with the bacterial pathogen Pseudomonas syringae. Within a fixed light/dark cycle, plant defense responses and disease resistance significantly depend on the time of day when pathogen contact takes place. Morning ...
Oberpichler Inga - - 2008
Response to changes in light conditions involves a variety of receptors that can modulate gene expression, enzyme activity and/or motility. For the study of light-regulated effects of Agrobacterium tumefaciens, we used a global analysis approach - proteomics - and compared the protein patterns of dark- and light-grown bacteria. These analyses ...
Schepens Isabelle - - 2008
Gravity and light are major factors shaping plant growth. Light perceived by phytochromes leads to seedling deetiolation, which includes the deviation from vertical hypocotyl growth and promotes hypocotyl phototropism. These light responses enhance survival of young seedlings during their emergence from the soil. The PHYTOCHROME KINASE SUBSTRATE (PKS) family is ...
Tao Yi Y Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA 92037, - - 2008
Plants grown at high densities perceive a decrease in the red to far-red (R:FR) ratio of incoming light, resulting from absorption of red light by canopy leaves and reflection of far-red light from neighboring plants. These changes in light quality trigger a series of responses known collectively as the shade ...
Kong Sam-Geun - - 2008
Light plays pivotal roles as an important environmental signal in plant growth and development. In Arabidopsis, phototropin 1 (phot1) and 2 (phot2) are the photoreceptors that mediate phototropism, chloroplast relocation, stomatal opening and leaf flattening, in response to blue light. However, little is known about how phototropins transduce the signals ...
Chen Hao - - 2008
Seed germination is regulated by endogenous hormonal cues and external environmental stimuli such as water, low temperature, and light. After germination, the young seedling must rapidly establish its root system and the photoautotrophic capability appropriate to its surrounding environment. Light and the phytohormone abscisic acid (ABA) both regulate seed germination ...
Hwang Yong-Sic - - 2008
We define the photoresponsiveness, during seedling de-etiolation, of PHYTOCHROME-INTERACTING FACTOR 3-LIKE 1 (PIL1), initially identified by microarray analysis as an early-response gene that is robustly repressed by first exposure to light. We show that PIL1 mRNA abundance declines rapidly, with a half-time of 15 min, to a new steady-state level, ...
Filiault Daniele L - - 2008
Plants have a sophisticated system for sensing and responding to their light environment. The light responses of populations and species native to different habitats show adaptive variation; understanding the mechanisms underlying photomorphogenic variation is therefore of significant interest. In Arabidopsis thaliana, phytochrome B (PHYB) is the dominant photoreceptor for red ...
Bou-Torrent Jordi - - 2008
Recent work has increased our understanding of the molecular and cellular mechanisms of the phytochrome family of photoreceptors in controlling plant photomorphogenesis. However, the importance of long-distance communication in controlling light responses has received relatively little attention and is poorly understood. In this article, by taking a closer look at ...
Riemann Maren - - 2008
Jasmonic acid (JA) is an important negative regulator of light-regulated coleoptile elongation in rice. We isolated rice JASMONATE RESISTANT 1 (osjar1) mutants from the Tos17 mutant panel by BLAST search. In far-red and blue lights, osjar1 coleoptiles were longer if compared with the wild type (WT), indicating that OsJar1 participates ...
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