Proteomic pattern-based analyses of light responses in Arabidopsis thaliana wild-type and photoreceptor mutants

Author: Kim, D.S.; Cho, D.S.; Park, W.-M.; Na, H.J.; Nam, H.G. Description: Light critically affects the physiology of plants. Using two-dimensional gel electrophoresis, we used a proteomics approach to analyze the responses of Arabidopsis thaliana to red (660 nm), far-red (730 nm) and blue (450 nm) light, which are utilized by type II and type I phytochromes, and blue light receptors, respectively. Under specific light treatments, the proteomic profiles of 49 protein spots exhibited over 1.8-fold difference in protein abundance, significant at p <0.05. Most of these proteins were metabolic…

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Comparative salt tolerance analysis between Arabidopsis thaliana and Thellungiella halophila, with special emphasis on K(+)/Na(+) selectivity and proline accumulation

Author: Ghars, M.A.; Parre, E.; Debez, A.; Bordenave, M.; Richard, L.; Leport, L.; Bouchereau, A.; Savoure, A.; Abdelly, C. Description: The eco-physiology of salt tolerance, with an emphasis on K(+) nutrition and proline accumulation, was investigated in the halophyte Thellungiella halophila and in both wild type and eskimo-1 mutant of the glycophyte Arabidopsis thaliana, which differ in their proline accumulation capacity. Plants cultivated in inert sand were challenged for 3 weeks with up to 500mM NaCl. Low salinity significantly decreased A. thaliana growth, whereas growth restriction was significant only at…

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Analysis of short-term changes in the Arabidopsis thaliana glycerolipidome in response to temperature and light

Author: Burgos, A.; Szymanski, J.; Seiwert, B.; Degenkolbe, T.; Hannah, M.A.; Giavalisco, P.; Willmitzer, L. Description: Although the influence of temperature, particularly cold, on lipid metabolism is well established, previous studies have focused on long-term responses and have largely ignored the influence of other interacting environmental factors. Here, we present a time-resolved analysis of the early responses of the glycerolipidome of Arabidopsis thaliana plants exposed to various temperatures (4, 21 and 32 degrees C) and light intensities (darkness, 75, 150 and 400 mumol m(-2) s(-1)), including selected combinations. Using a…

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Beyond transcription: RNA-binding proteins as emerging regulators of plant response to environmental constraints

Author: Ambrosone, A.; Costa, A.; Leone, A.; Grillo, S. Description: RNA-binding proteins (RBPs) govern many aspects of RNA metabolism, including pre-mRNA processing, transport, stability/decay and translation. Although relatively few plant RNA-binding proteins have been characterized genetically and biochemically, more than 200 RBP genes have been predicted in Arabidopsis and rice genomes, suggesting that they might serve specific plant functions. Besides their role in normal cellular functions, RBPs are emerging also as an interesting class of proteins involved in a wide range of post-transcriptional regulatory events that are important in providing…

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Axis determination in eggs of Xenopus laevis: a critical period before first cleavage, identified by the common effects of cold, pressure and ultraviolet irradiation

Author: Scharf, S.R.; Gerhart, J.C. Description: Exposure of eggs of Xenopus laevis to a temperature of 1.0 degree C for 4 min or a pressure of 8000 psi for 5 min in a critical period before first cleavage results in embryos exhibiting a reduction and loss of structures of the body axis. The deficiencies occur in a craniocaudal progression which is dose dependent. In the extreme, totally axis-deficient embryos with radial symmetry are formed. Maximum sensitivity to cold and pressure occurs at 0.6 of the time from fertilization to first…

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Altered developmental toxicity caused by three carrier solvents

Author: Rayburn, J.R.; DeYoung, D.J.; Bantle, J.A.; Fort, D.J.; McNew, R. Description: Many aquatic bioassays rely on chemical solvents to solubilize water-insoluble test materials. Interactions between solvents and test materials can lead to false positive or negative results. For this reason, tests for interactions between solvents and test materials were performed. The Frog Embryo Teratogenesis Assay–Xenopus (FETAX) was chosen because of its capacity to assess three different endpoints; mortality, malformation and embryo growth. Three solvents–dimethylsulfoxide (DMSO), acetone and triethylene glycol (TG)–were tested with two teratogens–methylmercury chloride (MMC) and trichloroethylene (TCE)….

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Protection of Xenopus laevis embryos against alcohol-induced delayed gut maturation and growth retardation by peroxiredoxin 5 and catalase

Author: Peng, Y.; Yang, P.-H.; Ng, S.S.M.; Lum, C.T.; Kung, H.-F.; Lin, M.C. Description: Accumulated evidence indicates that maternal alcohol consumption causes fetal enteric damage and growth retardation. In this study, we investigated the underlying molecular mechanisms in a Xenopus model of fetal alcohol exposure. We established a condition of transient alcohol exposure that produces tadpoles with delayed gut maturation and decreased body length. We then investigated the roles of reactive oxygen species (ROS) and reactive nitrogen species (RNS) by microinjecting plasmids expressing catalase and peroxiredoxin 5 (PRDX5) into two-cell…

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Catalase and peroxiredoxin 5 protect Xenopus embryos against alcohol-induced ocular anomalies

Author: Peng, Y.; Yang, P.-H.; Guo, Y.; Ng, S.S.M.; Liu, J.; Fung, P.C.W.; Tay, D.; Ge, J.; He, M.-L.; Kung, H.-F.; Lin, M.C. Description: PURPOSE: To study the molecular mechanisms underlying alcohol-induced ocular anomalies in Xenopus embryos. METHODS: Xenopus embryos were exposed to various concentrations (0.1%-0.5%) of alcohol, and the subsequent effects in eye development and in eye marker gene expression were determined. To investigate the role of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in fetal alcohol syndrome (FAS)-associated ocular injury, two antioxidant enzymes, catalase and peroxiredoxin…

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Craniofacial malformation in Xenopus laevis tadpoles caused by the exposure of early embryos to ethanol

Author: Nakatsuji, N. Description: The principal features of fetal alcohol syndrome (FAS) include microcephaly, reduced body size, and characteristic facial malformation, most of which are associated with hypoplasticity of structures around the mouth. A recent study using pregnant mice suggested that the malformations in FAS are caused by the effects of ethanol on early embryos during gastrulation and neurulation. Exposure of Xenopus laevis early embryos to 1-2% ethanol until they developed to the late neurula stage produced craniofacial malformations in tadpoles which have many similarities with the described features of…

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Xenopus laevis oocyte maturation is affected by metal chlorides

Author: Marin, M.; Slaby, S.; Marchand, G.; Demuynck, S.; Friscourt, N.; Gelaude, A.; Lemiere, S.; Bodart, J.-F. Description: Few studies have been conducted using Xenopus laevis germ cells as oocytes, though these cells offer many advantages allowing both electrophysiological studies and morphological examination. Our aim was to investigate the effects of metal (cadmium, lead, cobalt and zinc) exposures using cell biology approaches. First, cell survival was evaluated with both phenotypical and electrophysiological approaches. Secondly, the effect of metals on oocyte maturation was assessed with morphological observations and electrophysiological recordings. From…

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