ABSTRACT
To characterize the potential for exposure of amphibian terrestrial life stages to plant protection products (PPP), we studied the occurrence and habitat use of adult and metamorph common frogs (Rana temporaria) and common toads (Bufo bufo) in an agricultural landscape in Germany. The four selected study sites were breeding ponds with approximately 80% agricultural land within a 1-km radius. Adults were monitored by radio tracking for two years, and metamorph numbers were assessed for one summer using pitfall traps alongside drift fences. The results demonstrate that adults were rarely present in arable fields at any of the sites (overall 0.5% and 4% of total observations for frogs and toads, respectively). Metamorph captures in arable fields were more variable, ranging from 1.2% to 38.8% (frogs) and from 0.0% to 26.1% (toads) across study sites. Unsurprisingly, most captures in arable fields for both toad and frog metamorphs occurred at the site where the pond was completely surrounded by arable fields. Overall, the presence of adult amphibians in arable fields was limited and, for the metamorphs, occurred primarily when crops were denser and PPP spray interception higher. Diurnal hiding behavior was observed with the highest activity recorded at night, further reducing the risk of dermal exposure from direct PPP overspraying. In addition, it appeared that alternative habitats, such as woody structures or water bodies in the broader surrounding area, were preferred by the animals over the arable areas. The use of buffer zones around water bodies in agricultural areas would be an effective risk mitigation measure to protect terrestrial adults and metamorphs residing there and would reduce spray drift entry into water bodies during PPP application. It is hoped that these results will contribute to the discussion of risk assessment and mitigation options for amphibians. Integr Environ Assess Manag 2024;00:1-13. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
ABSTRACT
Upgradation of olefin-enriched Fischer-Tropsch cuts by the synthesis of alcohols leads to drop-in-capable biosynthetic fuels with low carbon emissions. As an alternative to the conventional two-step production of long-chain alcohols, tandem catalytic systems improve the energy and resource efficiency. Herein, we present an auto-tandem catalytic system for the production of alcohols from olefin-paraffin mixtures. By utilization of a tertiary alkanolamine as the ligand as well as the switchable component in the solvent system, a lean reaction system capable of catalyst recycling was developed. The system was characterized with regard to the switchable solvent separation approach and reaction parameters, resulting in alcohol yields of up to 99.5% and turnover frequencies of up to 764 h-1. By recycling the catalyst in 10 consecutive reactions, a total turnover number of 2810 was achieved.
ABSTRACT
Nucleosomal acetyltransferase of H4 (NuA4) is an essential transcriptional coactivator in eukaryotes, but remains poorly characterized in plants. Here, we describe Arabidopsis homologs of the NuA4 scaffold proteins Enhancer of Polycomb-Like 1 (AtEPL1) and Esa1-Associated Factor 1 (AtEAF1). Loss of AtEAF1 results in inhibition of growth and chloroplast development. These effects are stronger in the Atepl1 mutant and are further enhanced by loss of Golden2-Like (GLK) transcription factors, suggesting that NuA4 activates nuclear plastid genes alongside GLK. We demonstrate that AtEPL1 is necessary for nucleosomal acetylation of histones H4 and H2A.Z by NuA4 in vitro. These chromatin marks are diminished genome-wide in Atepl1, while another active chromatin mark, H3K9 acetylation (H3K9ac), is locally enhanced. Expression of many chloroplast-related genes depends on NuA4, as they are downregulated with loss of H4ac and H2A.Zac. Finally, we demonstrate that NuA4 promotes H2A.Z deposition and by doing so prevents spurious activation of stress response genes.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/physiology , Autotrophic Processes/physiology , Histones/metabolism , Nuclear Pore Complex Proteins/metabolism , Acetyltransferases , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Autotrophic Processes/genetics , Cell Nucleus/metabolism , Chloroplasts , Chromatin/metabolism , Ephrin-A1 , Gene Expression Regulation, Plant , Histones/genetics , Nuclear Pore Complex Proteins/genetics , Nucleosomes/metabolism , Stress, Physiological , Transcription Factors/metabolismABSTRACT
Pesticides used in seed coatings can influence seed consumption by birds and, therefore, actual exposure risk for them. A quantification of such effects on consumption is currently not regarded as a refinement factor in environmental risk assessments, although it is a possible option and should be considered, for example, for comparing exposure risk of different pesticides. It can highlight avoidance behavior, preventing birds from taking up lethal or sublethal pesticide doses. To formulate a standard, we developed an indoor test procedure based on established pen test methods, including 2- and no-choice phases with hunger periods. During testing, the highest standards of animal welfare were applied. Statistical approaches were used to determine the most appropriate number of replicates and for analysis. The effect on consumption of seeds is expressed as the ratio of consumed treated to untreated seeds. This consumption factor can be applied in avian risk assessments for seed treatments equivalent to an avoidance factor. We present, as an example, an application of the procedure to obtain a seed- and species-specific consumption factor for oilseed rape seeds (Brassica napus) provided untreated and treated with fungicides to greenfinches (Carduelis chloris) and Japanese quail (Coturnix japonica). Overall, bird constitution was not negatively affected by the test procedure in either species. The test procedure was suitable for showing differences in expected consumption patterns, such as greater avoidance of treated seeds in 2-choice than in no-choice tests. However, the consumption differed between species and fungicide treatments, allowing us to rank avoidance effects of different fungicides. Using the presented standard procedure to generate comparable pesticide- and species-specific consumption factors for more species and seed treatments may result in refinement of default values and reduce animal trials in different designs in the future. Environ Toxicol Chem 2020;39:359-370. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
Subject(s)
Animal Feed/standards , Coturnix/physiology , Feeding Behavior/drug effects , Finches/physiology , Pesticides/analysis , Seeds/chemistry , Animals , Avoidance Learning , Brassica napus/chemistry , Pesticides/toxicity , Risk Assessment , Species SpecificityABSTRACT
Objective: Past research has provided some preliminary evidence that ADHD and reactive aggression have overlapping neurocognitive bases. Based on this, we tested the hypothesis that ADHD symptoms are closely coupled in developmental terms with reactive aggression, more so than with proactive aggression with which it has been postulated to be only indirectly linked. Method: We used latent growth curve analysis to estimate the developmental relations between ADHD symptoms and subtypes of aggressive behavior in a normative sample of 1,571 youth (761 female, 810 male) measured from ages 7 to 15. Results: Individual ADHD trajectories were significantly and substantially correlated with individual trajectories in both aggressive subtypes; however, consistent with our hypothesis, the relation with reactive aggression was significantly stronger. Conclusion: Our study provides some of the first evidence for a differential relation between ADHD symptoms and aggression subtypes not only cross-sectionally but also in terms of their longitudinal developmental trajectories.
Subject(s)
Adolescent Behavior , Attention Deficit Disorder with Hyperactivity , Adolescent , Aggression , Attention Deficit Disorder with Hyperactivity/epidemiology , Child , Female , Humans , MaleSubject(s)
Community-Acquired Infections , Pneumonia , Aged , Humans , Proton Pump Inhibitors , ProtonsABSTRACT
Both anxiety and aggression commonly co-occur with ADHD symptoms. Two competing hypotheses describing the role of anxiety in aggression associated with ADHD symptoms have previously been advanced. The exacerbation hypothesis proposes that the presence of anxiety increases the risk of aggression in the context of ADHD symptoms. The attenuation hypothesis proposes that the presence of anxiety protects against aggression in the context of ADHD symptoms. We tested these hypotheses using moderated cross-lagged panel models in the Zurich project on social development from childhood to adulthood (z-proso) sample using both self-report (3 waves) and informant-report (8 waves) data spanning ages 7-17. We found evidence that anxiety protects against both reactive and proactive aggression; however, the effect was direct: there was no evidence for anxiety moderating the strength of ADHD symptom-aggression links. Results suggest that anxiety likely plays an important role in inhibiting aggression but does not interact with ADHD symptoms in the manner predicted by either the exacerbation or attenuation hypothesis.
Subject(s)
Aggression/psychology , Anxiety/diagnosis , Anxiety/psychology , Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit Disorder with Hyperactivity/psychology , Disease Progression , Adolescent , Aggression/physiology , Anxiety/epidemiology , Attention Deficit Disorder with Hyperactivity/epidemiology , Child , Cohort Studies , Cross-Sectional Studies , Female , Humans , Longitudinal Studies , Male , Self Report , Time Factors , Young AdultABSTRACT
OBJECTIVES: To estimate associations between long-term use of proton pump inhibitors (PPIs) and pneumonia incidence in older adults in primary care. DESIGN: Longitudinal analyses of electronic medical records. SETTING: England PARTICIPANTS: Individuals aged 60 and older in primary care receiving PPIs for 1 year or longer (N=75,050) and age- and sex-matched controls (N=75,050). MEASUREMENTS: Net hazard ratios for pneumonia incidence in Year 2 of treatment were estimated using the prior event rate ratio (PERR), which adjusts for pneumonia incidence differences before initiation of treatment. Inverse probability weighted models adjusted for 78 demographic, disease, medication, and healthcare usage measures. RESULTS: During the second year after initiating treatment, PPIs were associated with greater hazard of incident pneumonia (PERR-adjusted hazard ratio=1.82, 95% confidence interval=1.27-2.54), accounting for pretreatment pneumonia rates. Estimates were similar across age and comorbidity subgroups. Similar results were also obtained from propensity score- and inverse probability-weighted models. CONCLUSION: In a large cohort of older adults in primary care, PPI prescription was associated with greater risk of pneumonia in the second year of treatment. Results were robust across alternative analysis approaches. Controversies about the validity of reported short-term harms of PPIs should not divert attention from potential long-term effects of PPI prescriptions on older adults.
Subject(s)
Anti-Ulcer Agents/adverse effects , Community-Acquired Infections/chemically induced , Pneumonia/chemically induced , Proton Pump Inhibitors/adverse effects , Age Factors , Aged , Aged, 80 and over , Anti-Ulcer Agents/administration & dosage , Cohort Studies , Community-Acquired Infections/epidemiology , England/epidemiology , Female , Humans , Incidence , Male , Middle Aged , Pneumonia/epidemiology , Proton Pump Inhibitors/administration & dosage , Risk FactorsABSTRACT
The influence of the histone variant H2A.Z on transcription remains a long-standing conundrum. Here, by analyzing the actin-related protein6 mutant, which is impaired in H2A.Z deposition, and by H2A.Z profiling in stress conditions, we investigated the impact of this histone variant on gene expression in Arabidopsis thaliana We demonstrate that the arp6 mutant exhibits anomalies in response to osmotic stress. Indeed, stress-responsive genes are overrepresented among those hyperactive in arp6. In wild-type plants, these genes exhibit high levels of H2A.Z in the gene body. Furthermore, we observed that in drought-responsive genes, levels of H2A.Z in the gene body correlate with transcript levels. H2A.Z occupancy, but not distribution, changes in parallel with transcriptional changes. In particular, we observed H2A.Z loss upon transcriptional activation and H2A.Z gain upon repression. These data suggest that H2A.Z has a repressive role in transcription and counteracts unwanted expression in noninductive conditions. However, reduced activity of some genes in arp6 is associated with distinct behavior of H2A.Z at their +1 nucleosome, which exemplifies the requirement of this histone for transcription. Our data support a model where H2A.Z in gene bodies has a strong repressive effect on transcription, whereas in +1 nucleosomes, it is important for maintaining the activity of some genes.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Histones/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Droughts , Histones/genetics , Nucleosomes/genetics , Nucleosomes/metabolism , Promoter Regions, Genetic/genetics , Promoter Regions, Genetic/physiology , Transcription Initiation Site/physiology , Transcriptional Activation/genetics , Transcriptional Activation/physiologyABSTRACT
In plant cells, calcium-dependent protein kinases (CDPKs) are important sensors of Ca2+ flux resulting from various environmental stresses like cold, drought or salt stress. Previous genome sequence analysis and comparative studies in Arabidopsis (Arabidopsis thaliana L.) and rice (Oryza sativa L.) defined a multi-gene family of CDPKs. Here, we identified and characterised the CDPK gene complement of the model plant, barley (Hordeum vulgare L.). Comparative analysis encompassed phylogeny reconstruction based on newly available barley genome sequence, as well as established model genomes (e.g. O. sativa, A. thaliana, Brachypodium distachyon). Functional gene copies possessed characteristic CDPK domain architecture, including a serine/threonine kinase domain and four regulatory EF-hand motifs. In silico verification was followed by measurements of transcript abundance via real-time polymerase chain reaction (PCR). The relative expression of CDPK genes was determined in the vegetative growth stage under intensifying drought stress conditions. The majority of barley CDPK genes showed distinct changes in patterns of expression during exposure to stress. Our study constitutes evidence for involvement of the barley CDPK gene complement in signal transduction pathways relating to adaptation to drought. Our bioinformatics and transcriptomic analyses will provide an important foundation for further functional dissection of the barley CDPK gene family.
Subject(s)
Adaptation, Physiological/genetics , Droughts , Hordeum/genetics , Plant Proteins/genetics , Protein Kinases/genetics , Chromosome Mapping , Gene Expression Profiling , Genes, Plant , Multigene Family , Phylogeny , Real-Time Polymerase Chain Reaction , Signal Transduction , Stress, PhysiologicalABSTRACT
BACKGROUND: There is limited evidence on statin risk and effectiveness for patients aged 80+. We estimated risk of recurrent myocardial infarction, muscle-related and other adverse events, and statin-related incremental costs in "real-world" older patients treated with statins versus no statins. METHODS: We used primary care electronic medical records from the UK Clinical Practice Research Datalink. Subhazard ratios (competing risk of death) for myocardial infarction recurrence (primary end point), falls, fractures, ischemic stroke, and dementia, and hazard ratios (Cox) for all-cause mortality were used to compare older (60+) statin users and 1:1 propensity-score-matched controls (n = 12,156). Participants were followed-up for 10 years. RESULTS: Mean age was 76.5±9.2 years; 45.5% were women. Statins were associated with near significant reduction in myocardial infarction recurrence (subhazard ratio = 0.84, 0.69-1.02, p = .073), with protective effect in the 60-79 age group (0.73, 0.57-0.94) but a nonsignificant result in the 80+ group (1.06, 0.78-1.44; age interaction p = .094). No significant associations were found for stroke or dementia. Data suggest an increased risk of falls (1.36, 1.17-1.60) and fractures (1.33, 1.04-1.69) in the first 2 years of treatment, particularly in the 80+ group. Treatment was associated with lower all-cause mortality. Statin use was associated with health care cost savings in the 60-79 group but higher costs in the 80+ group. CONCLUSIONS: Estimates of statin effectiveness for the prevention of recurrent myocardial infarction in patients aged 60-79 years were similar to trial results, but more evidence is needed in the older group. There may be an excess of falls and fractures in very old patients, which deserves further investigation.
Subject(s)
Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Myocardial Infarction/prevention & control , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Male , Middle Aged , Non-Randomized Controlled Trials as Topic , Retrospective Studies , Secondary Prevention , Treatment OutcomeABSTRACT
Increasing the drought tolerance of crops is one of the most challenging goals in plant breeding. To improve crop productivity during periods of water deficit, it is essential to understand the complex regulatory pathways that adapt plant metabolism to environmental conditions. Among various plant hormones and second messengers, calcium ions are known to be involved in drought stress perception and signaling. Plants have developed specific calcium-dependent protein kinases that convert calcium signals into phosphorylation events. In this study we attempted to elucidate the role of a calcium-dependent protein kinase in the drought stress response of barley (Hordeum vulgare L.), one of the most economically important crops worldwide. The ongoing barley genome project has provided useful information about genes potentially involved in the drought stress response, but information on the role of calcium-dependent kinases is still limited. We found that the gene encoding the calcium-dependent protein kinase HvCPK2a was significantly upregulated in response to drought. To better understand the role of HvCPK2a in drought stress signaling, we generated transgenic Arabidopsis plants that overexpressed the corresponding coding sequence. Overexpressing lines displayed drought sensitivity, reduced nitrogen balance index (NBI), an increase in total chlorophyll content and decreased relative water content. In addition, in vitro kinase assay experiments combined with mass spectrometry allowed HvCPK2a autophosphorylation sites to be identified. Our results suggest that HvCPK2a is a dual-specificity calcium-dependent protein kinase that functions as a negative regulator of the drought stress response in barley.
ABSTRACT
Phosphorylation and dephosphorylation events play an important role in the transmission of the ABA signal. Although SnRK2 [sucrose non-fermenting1-related kinase2] protein kinases and group A protein phosphatase type 2C (PP2C)-type phosphatases constitute the core ABA pathway, mitogen-activated protein kinase (MAPK) pathways are also involved in plant response to ABA. However, little is known about the interplay between MAPKs and PP2Cs or SnRK2 in the regulation of ABA pathways. In this study, an effort was made to elucidate the role of MAP kinase kinase kinase18 (MKKK18) in relation to ABA signaling and response. The MKKK18 knockout lines showed more vigorous root growth, decreased abaxial stomatal index and increased stomatal aperture under normal growth conditions, compared with the control wild-type Columbia line. In addition to transcriptional regulation of the MKKK18 promoter by ABA, we demonstrated using in vitro and in vivo kinase assays that the kinase activity of MKKK18 was regulated by ABA. Analysis of the cellular localization of MKKK18 showed that the active kinase was targeted specifically to the nucleus. Notably, we identified abscisic acid insensitive 1 (ABI1) PP2C as a MKKK18-interacting protein, and demonstrated that ABI1 inhibited its activity. Using a cell-free degradation assay, we also established that MKKK18 was unstable and was degraded by the proteasome pathway. The rate of MKKK18 degradation was delayed in the ABI1 knockout line. Overall, we provide evidence that ABI1 regulates the activity and promotes proteasomal degradation of MKKK18.
Subject(s)
Abscisic Acid/pharmacology , Arabidopsis Proteins/metabolism , Arabidopsis/enzymology , MAP Kinase Kinase Kinases/metabolism , Phosphoprotein Phosphatases/metabolism , Proteasome Endopeptidase Complex/metabolism , Signal Transduction/drug effects , Ubiquitins/metabolism , Arabidopsis/drug effects , Arabidopsis/genetics , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Enzyme Activation/drug effects , Germination/drug effects , Models, Biological , Mutation/genetics , Phenotype , Plant Roots/drug effects , Plant Roots/growth & development , Plant Stomata/drug effects , Plant Stomata/growth & development , Plants, Genetically Modified , Promoter Regions, Genetic/genetics , Protein Binding/drug effects , Protein Phosphatase 2C , Protein Transport/drug effects , Protoplasts/drug effects , Protoplasts/metabolism , Subcellular Fractions/metabolism , NicotianaABSTRACT
In this report we characterized the Arabidopsis ABI1 gene orthologue and Brassica napus gene paralogues encoding protein phosphatase 2C (PP2C, group A), which is known to be a negative regulator of the ABA signaling pathway. Six homologous B. napus sequences were identified and characterized as putative PP2C group A members. To gain insight into the conservation of ABI1 function in Brassicaceae, and understand better its regulatory effects in the drought stress response, we generated transgenic B. napus plants overexpressing A. thaliana ABI1. Transgenic plants subjected to drought showed a decrease in relative water content, photosynthetic pigments content and expression level of RAB18- and RD19A-drought-responsive marker genes relative to WT plants. We present the characterization of the drought response of B. napus with the participation of ABI1-like paralogues. The expression pattern of two evolutionarily distant paralogues, BnaA01.ABI1.a and BnaC07.ABI1.b in B. napus and their promoter activity in A. thaliana showed differences in the induction of the paralogues under dehydration stress. Comparative sequence analysis of both BnaABI1 promoters showed variation in positions of cis-acting elements that are especially important for ABA- and stress-inducible expression. Together, these data reveal that subfunctionalization following gene duplication may be important in the maintenance and functional divergence of the BnaABI1 paralogues. Our results provide a framework for a better understanding of (1) the role of ABI1 as a hub protein regulator of the drought response, and (2) the differential involvement of the duplicated BnaABI1 genes in the response of B. napus to dehydration-related stresses.
Subject(s)
Brassica napus/genetics , Brassica napus/metabolism , Genes, Plant , Phosphoprotein Phosphatases/genetics , Plant Proteins/genetics , Abscisic Acid/metabolism , Amino Acid Sequence , Arabidopsis/enzymology , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Base Sequence , Chlorophyll/metabolism , DNA, Plant/genetics , Droughts , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Molecular Sequence Data , Phosphoprotein Phosphatases/metabolism , Phylogeny , Plant Growth Regulators/metabolism , Plant Proteins/metabolism , Plants, Genetically Modified , Promoter Regions, Genetic , Protein Phosphatase 2C , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Signal Transduction , Stress, Physiological , Water/metabolismABSTRACT
BACKGROUND: Histone acetyltransferase complex NuA4 and histone variant exchanging complex SWR1 are two chromatin modifying complexes which act cooperatively in yeast and share some intriguing structural similarities. Protein subunits of NuA4 and SWR1-C are highly conserved across eukaryotes, but form different multiprotein arrangements. For example, the human TIP60-p400 complex consists of homologues of both yeast NuA4 and SWR1-C subunits, combining subunits necessary for histone acetylation and histone variant exchange. It is currently not known what protein complexes are formed by the plant homologues of NuA4 and SWR1-C subunits. RESULTS: We report on the identification and molecular characterization of AtEAF1, a new subunit of Arabidopsis NuA4 complex which shows many similarities to the platform protein of the yeast NuA4 complex. AtEAF1 copurifies with Arabidopsis homologues of NuA4 and SWR1-C subunits ARP4 and SWC4 and interacts physically with AtYAF9A and AtYAF9B, homologues of the YAF9 subunit. Plants carrying a T-DNA insertion in one of the genes encoding AtEAF1 showed decreased FLC expression and early flowering, similarly to Atyaf9 mutants. Chromatin immunoprecipitation analyses of the single mutant Ateaf1b-2 and artificial miRNA knock-down Ateaf1 lines showed decreased levels of H4K5 acetylation in the promoter regions of major flowering regulator genes, further supporting the role of AtEAF1 as a subunit of the plant NuA4 complex. CONCLUSIONS: Growing evidence suggests that the molecular functions of the NuA4 and SWR1 complexes are conserved in plants and contribute significantly to plant development and physiology. Our work provides evidence for the existence of a yeast-like EAF1 platform protein in A. thaliana, filling an important gap in the knowledge about the subunit organization of the plant NuA4 complex.
Subject(s)
Acetyltransferases/metabolism , Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Multiprotein Complexes/metabolism , Acetylation/drug effects , Amino Acid Sequence , Arabidopsis/drug effects , Arabidopsis/enzymology , Arabidopsis/genetics , Arabidopsis Proteins/chemistry , Arabidopsis Proteins/genetics , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Flowers/drug effects , Flowers/physiology , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Histones/metabolism , Hydroxamic Acids/pharmacology , MicroRNAs/genetics , MicroRNAs/metabolism , Molecular Sequence Data , Mutation/genetics , Protein Binding/drug effects , Protein Structure, Tertiary , RNA, Messenger/genetics , RNA, Messenger/metabolism , Saccharomyces cerevisiae/metabolism , Transcription, Genetic/drug effectsABSTRACT
Ethylene plays a crucial role in various biological processes and therefore its biosynthesis is strictly regulated by multiple mechanisms. Posttranslational regulation, which is pivotal in controlling ethylene biosynthesis, impacts 1-aminocyclopropane 1-carboxylate synthase (ACS) protein stability via the complex interplay of specific factors. Here, we show that the Arabidopsis thaliana protein phosphatase type 2C, ABI1, a negative regulator of abscisic acid signaling, is involved in the regulation of ethylene biosynthesis under oxidative stress conditions. We found that ABI1 interacts with ACS6 and dephosphorylates its C-terminal fragment, a target of the stress-responsive mitogen-activated protein kinase, MPK6. In addition, ABI1 controls MPK6 activity directly and by this means also affects the ACS6 phosphorylation level. Consistently with this, ozone-induced ethylene production was significantly higher in an ABI1 knockout strain (abi1td) than in wild-type plants. Importantly, an increase in stress-induced ethylene production in the abi1td mutant was compensated by a higher ascorbate redox state and elevated antioxidant activities. Overall, the results of this study provide evidence that ABI1 restricts ethylene synthesis by affecting the activity of ACS6. The ABI1 contribution to stress phenotype underpins its role in the interplay between the abscisic acid (ABA) and ethylene signaling pathways.
Subject(s)
Arabidopsis Proteins/metabolism , Ethylenes/biosynthesis , Lyases/metabolism , Ozone , Phosphoprotein Phosphatases/metabolism , Arabidopsis , Gene Expression Regulation, Plant/drug effects , Protein Binding , Protein Phosphatase 2C , Signal Transduction/drug effectsABSTRACT
We studied whether the origins of math anxiety can be related to a biologically supported framework of stress induction: (un)controllability perception, here indicated by self-reported independent efforts in mathematics. Math anxiety was tested in 182 children (8- to 11-year-olds). Latent factor modeling was used to test hypotheses on plausible causal processes and mediations within competing models in quasi-experimental contrasts. Uncontrollability perception in mathematics, or (in)dependence of efforts, best fit the data as an antecedent of math anxiety. In addition, the relationship of math anxiety with gender was fully mediated by adaptive perception of control (i.e. controllability). That is, young boys differ from girls in terms of their experience of control in mathematics learning. These differences influence math anxiety. Our findings are consistent with recent suggestions in clinical literature according to which uncontrollability makes women more susceptible to fear and anxiety disorders.
Subject(s)
Internal-External Control , Mathematics/education , Models, Psychological , Performance Anxiety/physiopathology , Bayes Theorem , Child , Female , Humans , Likelihood Functions , Male , Regression Analysis , Sex FactorsABSTRACT
In this controlled experiment we examined whether there are content effects in verbal short-term memory and working memory for verbal stimuli. Thirty-seven participants completed forward and backward digit and letter recall tasks, which were constructed to control for distance effects between stimuli. A maximum-likelihood mixed-effects logistic regression revealed main effects of direction of recall (forward vs backward) and content (digits vs letters). There was an interaction between type of recall and content, in which the recall of digits was superior to the recall of letters in verbal short-term memory but not in verbal working memory. These results demonstrate that the recall of information from verbal short-term memory is content-specific, whilst the recall of information from verbal working memory is content-general.
Subject(s)
Language , Mental Recall/physiology , Neuropsychological Tests , Acoustic Stimulation , Adult , Female , Humans , Male , Memory, Short-Term/physiology , Young AdultABSTRACT
In higher plants, copper ions, hydrogen peroxide, and cycloheximide have been recognized as very effective inducers of the transcriptional activity of genes encoding the enzymes of the ethylene biosynthesis pathway. In this report, the transcriptional patterns of genes encoding the 1-aminocyclopropane-1-carboxylate synthases (ACSs), 1-aminocyclopropane-1-carboxylate oxidases (ACOs), ETR1, ETR2, and ERS1 ethylene receptors, phospholipase D (PLD)-alpha1, -alpha2, -gamma1, and -delta, and respiratory burst oxidase homologue (Rboh)-NADPH oxidase-D and -F in response to these inducers in Brassica oleracea etiolated seedlings are shown. ACS1, ACO1, ETR2, PLD-gamma1, and RbohD represent genes whose expression was considerably affected by all of the inducers used. The investigations were performed on the seedlings with (i) ethylene insensitivity and (ii) a reduced level of the PLD-derived phosphatidic acid (PA). The general conclusion is that the expression of ACS1, -3, -4, -5, -7, and -11, ACO1, ETR1, ERS1, and ETR2, PLD-gamma 1, and RbohD and F genes is undoubtedly under the reciprocal cross-talk of the ethylene and PA(PLD) signalling routes; both signals affect it in concerted or opposite ways depending on the gene or the type of stimuli. The results of these studies on broccoli seedlings are in agreement with the hypothesis that PA may directly affect the ethylene signal transduction pathway via an inhibitory effect on CTR1 (constitutive triple response 1) activity.