Rapid transcriptional and metabolic regulation of the deacclimation process in cold acclimated Arabidopsis thaliana

Background: During low temperature exposure, temperate plant species increase their freezing tolerance in a process termed cold acclimation. This is accompanied by dampened oscillations of circadian clock genes and disrupted oscillations of output genes and metabolites. During deacclimation in response to warm temperatures, cold acclimated plants lose freezing tolerance and resume growth and development. While considerable effort has been directed toward understanding the molecular and metabolic basis of cold acclimation, much less information is available about the regulation of deacclimation.Results: We report metabolic (gas chromatography-mass spectrometry) and transcriptional (microarrays, quantitative RT-PCR) responses underlying deacclimation during the first 24 h after a shift of Arabidopsis thaliana (Columbia-0) plants cold acclimated at 4 °C back to warm temperature (20 °C). The data reveal a faster response of the transcriptome than of the metabolome and provide evidence for tightly regulated temporal responses at both levels. Metabolically, deacclimation is associated with decreasing contents of sugars, amino acids, glycolytic and TCA cycle intermediates, indicating an increased need for carbon sources and respiratory energy production for the activation of growth. The early phase of deacclimation also involves extensive down-regulation of protein synthesis and changes in the metabolism of lipids and cell wall components. Hormonal regulation appears particularly important during deacclimation, with extensive changes in the expression of genes related to auxin, gibberellin, brassinosteroid, jasmonate and ethylene metabolism. Members of several transcription factor families that control fundamental aspects of morphogenesis and development are significantly regulated during deacclimation, emphasizing that loss of freezing tolerance and growth resumption are transcriptionally highly interrelated processes. Expression patterns of some clock oscillator components resembled those under warm conditions, indicating at least partial re-activation of the circadian clock during deacclimation.Conclusions: This study provides the first combined metabolomic and transcriptomic analysis of the regulation of deacclimation in cold acclimated plants. The data indicate cascades of rapidly regulated genes and metabolites that underlie the developmental switch resulting in reduced freezing tolerance and the resumption of growth. They constitute a large-scale dataset of genes, metabolites and pathways that are crucial during the initial phase of deacclimation. The data will be an important reference for further analyses of this and other important but under-researched stress deacclimation processes

Use of mass-participation outdoor events to assess human exposure to tickborne pathogens

Mapping the public health threat of tickborne pathogens requires quantification of not only the density of infected host-seeking ticks but also the rate of human exposure to these ticks. To efficiently sample a high number of persons in a short time, we used a mass-participation outdoor event. In June 2014, we sampled ≈500 persons competing in a 2-day mountain marathon run across predominantly tick-infested habitat in Scotland. From the number of tick bites recorded and prevalence of tick infection with Borrelia burgdoferi sensu lato and B. miyamotoi, we quantified the frequency of competitor exposure to the pathogens. Mass-participation outdoor events have the potential to serve as excellent windows for epidemiologic study of tickborne pathogens; their concerted use should improve spatial and temporal mapping of human exposure to infected ticks

Alterations in Cytosolic Glucose-Phosphate Metabolism Affect Structural Features and Biochemical Properties of Starch-Related Heteroglycans1[W]

The cytosolic pools of glucose-1-phosphate (Glc-1-P) and glucose-6-phosphate are essential intermediates in several biosynthetic paths, including the formation of sucrose and cell wall constituents, and they are also linked to the cytosolic starch-related heteroglycans. In this work, structural features and biochemical properties of starch-related heteroglycans were analyzed as affected by the cytosolic glucose monophosphate metabolism using both source and sink organs from wild-type and various transgenic potato (Solanum tuberosum) plants. In leaves, increased levels of the cytosolic phosphoglucomutase (cPGM) did affect the cytosolic heteroglycans, as both the glucosyl content and the size distribution were diminished. By contrast, underexpression of cPGM resulted in an unchanged size distribution and an unaltered or even increased glucosyl content of the heteroglycans. Heteroglycans prepared from potato tubers were found to be similar to those from leaves but were not significantly affected by the level of cPGM activity. However, external glucose or Glc-1-P exerted entirely different effects on the cytosolic heteroglycans when added to tuber discs. Glucose was directed mainly toward starch and cell wall material, but incorporation into the constituents of the cytosolic heteroglycans was very low and roughly reflected the relative monomeric abundance. By contrast, Glc-1-P was selectively taken up by the tuber discs and resulted in a fast increase in the glucosyl content of the heteroglycans that quantitatively reflected the level of the cytosolic phosphorylase activity. Based on 14C labeling experiments, we propose that in the cytosol, glucose and Glc-1-P are metabolized by largely separated paths

Additional file 7: of Rapid transcriptional and metabolic regulation of the deacclimation process in cold acclimated Arabidopsis thaliana

Distribution of metabolites with significantly changed pool sizes among the clusters shown in Fig. 4. Major clusters in Fig. 4 are indicated by letters, while small cluster with only one or a few metabolites are indicated by numbers. (XLSX 11 kb

Shortened night sleep impairs facial responsiveness to emotional stimuli

Sleep deprivation deteriorates mood, impairs the recognition of facial expressions, and affects the ability to regulate emotions. The present study investigated the effect of partial sleep deprivation on facial responses to emotional stimuli.Thirty-three healthy undergraduates were tested twice: after a night with (i) 8 h and (ii) 4 h sleep. Self-reported sleepiness and sustained attention (Psychomotor Vigilance Task) were assessed. Emotional reactivity was measured with facial Electromyogram (EMG) while participants were asked to respond with either compatible or incompatible facial muscles to emotional stimuli in order to study whether partial sleep deprivation caused slower reactions mainly in response to incompatible stimuli (due to an additional effort to suppress the compatible reaction caused by decreased inhibitory control) or in response to both compatible and incompatible stimuli.Self-reported sleepiness and reaction times in a sustained attention task significantly increased after one night of partial sleep deprivation. Facial reactions to emotional stimuli were decelerated. No significant interaction between sleep restriction and compatibility of the muscle to the picture valence could be observed.Hence, volitional facial reactions in response to emotional stimuli were slower after one night of reduced sleep, but affective inhibitory control was not significantly impaired. However, slowed facial responding to emotional stimuli may affect social interaction after sleep restriction

Additional file 4: of Rapid transcriptional and metabolic regulation of the deacclimation process in cold acclimated Arabidopsis thaliana

Distribution of 476 significantly regulated genes encoding transcription factors among the clusters shown in Fig. 2. Major clusters in Fig. 2 are indicated by letters, while small cluster with only one or a few TF genes are indicated by numbers. (XLSX 33 kb

Description of the early stage of pandemic (H1N1) 2009 in Germany, 27 April-16 June 2009

We report characteristics of the early stage of the pandemic (H1N1) 2009 in Germany. Until 16 June 2009, 198 confirmed cases were notified. Almost half of the cases (47%) were imported, mostly from Mexico and the United States. About two third of indigenous cases were outbreak-related (with two large school-associated outbreaks, n=74). According to our results Germany is still in the early stage of the pandemic with limited domestic transmission