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Author (up) Ambrosone, A.; Costa, A.; Leone, A.; Grillo, S. file  url
doi  openurl
  Title Beyond transcription: RNA-binding proteins as emerging regulators of plant response to environmental constraints Type Journal Article
  Year 2012 Publication Plant Science : an International Journal of Experimental Plant Biology Abbreviated Journal Plant Sci  
  Volume 182 Issue Pages 12-18  
  Keywords Abscisic Acid/metabolism; Acclimatization/*physiology; Gene Expression Regulation, Plant; Osmotic Pressure/physiology; *Plant Physiological Processes; Plants/genetics; RNA-Binding Proteins/genetics/metabolism/*physiology; Transcription, Genetic  
  Abstract 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 plants with the ability to respond rapidly to changes in environmental conditions. Here, we review the most recent results and evidence on the functional role of RBPs in plant adaptation to various unfavourable environmental conditions and their contribution to enhance plant tolerance to abiotic stresses, with special emphasis on osmotic and temperature stress.  
  Call Number Serial 1226  
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Author (up) Anderson, J.L.; Albergotti, L.; Ellebracht, B.; Huey, R.B.; Phillips, P.C. file  url
  Title Does thermoregulatory behavior maximize reproductive fitness of natural isolates of Caenorhabditis elegans? Type Journal Article
  Year 2011 Publication BMC Evolutionary Biology Abbreviated Journal BMC Evol Biol  
  Volume 11 Issue Pages 157  
  Keywords Acclimatization; Animals; Body Temperature Regulation; Caenorhabditis elegans--genetics, physiology; Genetic Fitness; Temperature  
  Abstract BACKGROUND: A central premise of physiological ecology is that an animal's preferred body temperature should correspond closely with the temperature maximizing performance and Darwinian fitness. Testing this co-adaptational hypothesis has been problematic for several reasons. First, reproductive fitness is the appropriate measure, but is difficult to measure in most animals. Second, no single fitness measure applies to all demographic situations, complicating interpretations. Here we test the co-adaptation hypothesis by studying an organism (Caenorhabditis elegans) in which both fitness and thermal preference can be reliably measured. RESULTS: We find that natural isolates of C. elegans display a range of mean thermal preferences and also vary in their thermal sensitivities for fitness. Hot-seeking isolates CB4854 and CB4857 prefer temperatures that favor population growth rate (r), whereas the cold-seeking isolate CB4856 prefers temperatures that favor Lifetime Reproductive Success (LRS). CONCLUSIONS: Correlations between fitness and thermal preference in natural isolates of C. elegans are driven primarily by isolate-specific differences in thermal preference. If these differences are the result of natural selection, then this suggests that the appropriate measure of fitness for use in evolutionary ecology studies might differ even within species, depending on the unique ecological and evolutionary history of each population.  
  Call Number Serial 261  
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Author (up) Anderson, J.L.; Albergotti, L.; Proulx, S.; Peden, C.; Huey, R.B.; Phillips, P.C. file  url
  Title Thermal preference of Caenorhabditis elegans: a null model and empirical tests Type Journal Article
  Year 2007 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 210 Issue Pt 17 Pages 3107-3116  
  Keywords Acclimatization; Animals; Behavior, Animal; Body Temperature Regulation; Caenorhabditis elegans--physiology; Escherichia coli--growth & development; Models, Biological; Temperature  
  Abstract The preferred body temperature of ectotherms is typically inferred from the observed distribution of body temperatures in a laboratory thermal gradient. For very small organisms, however, that observed distribution might misrepresent true thermal preferences. Tiny ectotherms have limited thermal inertia, and so their body temperature and speed of movement will vary with their position along the gradient. In order to separate the direct effects of body temperature on movement from actual preference behaviour on a thermal gradient, we generate a null model (i.e. of non-thermoregulating individuals) of the spatial distribution of ectotherms on a thermal gradient and test the model using parameter values estimated from the movement of nematodes (Caenorhabditis elegans) at fixed temperatures and on a thermal gradient. We show that the standard lab strain N2, which is widely used in thermal gradient studies, avoids high temperature but otherwise does not exhibit a clear thermal preference, whereas the Hawaiian natural isolate CB4856 shows a clear preference for cool temperatures ( approximately 17 degrees C). These differences are not influenced substantially by changes in the starting position of worms in the gradient, the natal temperature of individuals or the presence and physiological state of bacterial food. These results demonstrate the value of an explicit null model of thermal effects and highlight problems in the standard model of C. elegans thermotaxis, showing the value of using natural isolates for tests of complex natural behaviours.  
  Call Number Serial 260  
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Author (up) Lichtenthaler, H.K. file  url
  Title The stress concept in plants: an introduction Type Journal Article
  Year 1998 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci  
  Volume 851 Issue Pages 187-198  
  Keywords Acclimatization/physiology; Environment; Molecular Structure; Photons; Plant Physiological Phenomena; Plants/*metabolism; Reactive Oxygen Species/metabolism; Signal Transduction/physiology; Stress, Mechanical; Xanthophylls; beta Carotene/analogs & derivatives/metabolism  
  Abstract The current concept of stress in plants has been well developed over the past 60 years. Any unfavorable condition or substance that affects or blocks a plant's metabolism, growth, or development is regarded as stress. Vegetation stress can be induced by various natural and anthropogenic stress factors. One has to differentiate between short-term and long-term stress effects as well as between low-stress events that can be partially compensated for by acclimation, adaptation, and repair mechanisms, on the one hand, and strong stress or chronic stress events causing considerable damage that may eventually lead to cell and plant death, on the other hand. Some essential stress syndrome responses of plants are summarized in a unifying stress concept. The major abiotic, biotic, and anthropogenic stressors are listed. Some stress tolerance mechanisms are mentioned. Stress conditions and stress-induced damage in plants have so far been detected using the classical ecophysiological field methods as well as point data measurements of particular chlorophyll fluorescence parameters and of reflectance spectra. The novel laser-induced high-resolution fluorescence imaging technique, which integrates chlorophyll and blue-green fluorescence, marks a new standard in the detection of stress in plants.  
  Call Number Serial 528  
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Author (up) Powell, M.L.; Watts, S.A. file  url
  Title Effect of temperature acclimation on metabolism and hemocyanin binding affinities in two crayfish, Procambarus clarkii and Procambarus zonangulus Type Journal Article
  Year 2006 Publication Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology Abbreviated Journal Comp Biochem Physiol A Mol Integr Physiol  
  Volume 144 Issue 2 Pages 211-217  
  Keywords Acclimatization/*physiology; Animals; Astacoidea/*metabolism; Basal Metabolism; *Body Temperature Regulation; Carrier Proteins/metabolism; Climate; Ecosystem; Female; Geography; Hemocyanin/*metabolism; Isoelectric Focusing; Male; Oxygen Consumption; Temperature  
  Abstract Procambarus clarkii and Procambarus zonangulus are two of the most widespread crayfish species in North America. In regions where their ranges overlap species composition can vary greatly. The physiological basis for this variable species composition is unknown. Temperature and oxygen level are two parameters that vary in shallow water habitats. We examined the metabolic rate and hemocyanin binding affinities in relation to thermal history. Temperature acclimation did not have the predicted effect on metabolic rate. Acclimation to high temperature (30 degrees C) decreased metabolic rate at 35 degrees C for both species. Low temperature acclimation (10 degrees C) resulted in 20% mortality in P. clarkii and 100% mortality in P. zonangulus when exposed to 35 degrees C. The range of P. clarkii is known to extend farther south than that of P. zonangulus, and this response may be a consequence of adaptations to higher temperatures in this range. Hemocyanin binding affinity was directly affected by assay and acclimation temperature. The highest P(50) values were recorded for crayfish of both species acclimated to 10 degrees C and assayed at 30 degrees C. There was also a shift in the isoelectric points of hemolymph proteins (possibly due to structural changes) that correlated with and an increase in the hemocyanin binding affinity following acclimation to high temperatures (30 degrees C) in both species.  
  Call Number Serial 1339  
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