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Sample records for acid stress response

  1. Acid tolerance response (ATR) of microbial communities during the enhanced biohydrogen process via cascade acid stress.

    Science.gov (United States)

    Lin, Xiaoqin; Xia, Yan; Yan, Qun; Shen, Wei; Zhao, Mingxing

    2014-03-01

    Enhanced biohydrogen production via cascade acid stress on microbial communities, structure patterns of the microbial communities revealed by PLFAs, and the succession of biohydrogen related species against cascade acid stress were all investigated. It was found that hydrogen production could be improved from 48.7 to 79.4mL/gVS after cascade acid stress. In addition, the Gram negative (G(-)) bacteria were found to be more tolerant to organic acids than those of the Gram positive (G(+)) bacteria, regardless of the dominance of G(+) bacteria within the microbial communities. Moreover, Clostridium butyricum, Clostridium aciditolerans and Azospira oryzae, were proved to be enriched, and then might play indispensable roles for the enhanced biohydrogen production after cascade acid stress, as which were responsible for the biohydrogen accumulation, acid tolerance and nitrogen removal, respectively.

  2. Plasma omega 3 polyunsaturated fatty acid status and monounsaturated fatty acids are altered by chronic social stress and predict endocrine responses to acute stress in titi monkeys

    Science.gov (United States)

    Disturbances in fatty acid (FA) metabolism may link chronic psychological stress, endocrine responsiveness, and psychopathology. Therefore, lipid metabolome-wide responses and their relationships with endocrine (cortisol; insulin; adiponectin) responsiveness to acute stress (AS) were assessed in a ...

  3. Plant water stress: Associations between ethylene and abscisic acid response

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    Carolina Salazar

    2015-08-01

    Full Text Available Agriculture is severely impacted by water stress due either to excess (hypoxia/anoxia or deficit of water availability. Hypoxia/anoxia is associated with oxygen (O2 deficiency or depletion, inducing several anatomical, morphological, physiological, and molecular changes. The majority of these alterations are adaptive mechanisms to cope with low O2 availability; among them, alterations in shoot length, aerenchyma formation and adventitious roots have been described in several studies. The aim of this review was to address the association between abscisic acid (ABA and ethylene in function of water availability in plants. The major physiological responses to low O2 are associated with changes in root respiration, stomatal conductance, photosynthesis, and fermentation pathways in roots. In addition, several changes in gene expression have been associated with pathways that are not present under normal O2 supply. The expression of ethylene receptor genes is up-regulated by low O2, and ethylene seems to have a crucial role in anatomical and physiological effects during hypoxia/anoxia. During O2 depletion, ethylene accumulation down-regulates ABA by inhibiting rate-limiting enzymes in ABA biosynthesis and by activating ABA breakdown to phaseic acid. With regard to water deficit, drought is primarily sensed by the roots, inducing a signal cascade to the shoots via xylem causing physiological and morphological changes. Several genes are regulated up or down with osmotic stress; the majority of these responsive genes can be driven by either an ABA-dependent or ABA-independent pathway. Some studies suggest that ethylene shuts down leaf growth very fast after the plant senses limited water availability. Ethylene accumulation can antagonize the control of gas exchange and leaf growth upon drought and ABA accumulation.

  4. Physiological responses of Daphnia pulex to acid stress

    OpenAIRE

    Pirow Ralph; Weber Anna K

    2009-01-01

    Abstract Background Acidity exerts a determining influence on the composition and diversity of freshwater faunas. While the physiological implications of freshwater acidification have been intensively studied in teleost fish and crayfish, much less is known about the acid-stress physiology of ecologically important groups such as cladoceran zooplankton. This study analyzed the extracellular acid-base state and CO2 partial pressure (PCO2), circulation and ventilation, as well as the respiratio...

  5. Physiological responses of Daphnia pulex to acid stress

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    Pirow Ralph

    2009-04-01

    Full Text Available Abstract Background Acidity exerts a determining influence on the composition and diversity of freshwater faunas. While the physiological implications of freshwater acidification have been intensively studied in teleost fish and crayfish, much less is known about the acid-stress physiology of ecologically important groups such as cladoceran zooplankton. This study analyzed the extracellular acid-base state and CO2 partial pressure (PCO2, circulation and ventilation, as well as the respiration rate of Daphnia pulex acclimated to acidic (pH 5.5 and 6.0 and circumneutral (pH 7.8 conditions. Results D. pulex had a remarkably high extracellular pH of 8.33 and extracellular PCO2 of 0.56 kPa under normal ambient conditions (pH 7.8 and normocapnia. The hemolymph had a high bicarbonate concentration of 20.9 mM and a total buffer value of 51.5 meq L-1 pH-1. Bicarbonate covered 93% of the total buffer value. Acidic conditions induced a slight acidosis (ΔpH = 0.16–0.23, a 30–65% bicarbonate loss, and elevated systemic activities (tachycardia, hyperventilation, hypermetabolism. pH 6.0 animals partly compensated the bicarbonate loss by increasing the non-bicarbonate buffer value from 2.0 to 5.1 meq L-1 pH-1. The extracellular PCO2 of pH 5.5 animals was significantly reduced to 0.33 kPa, and these animals showed the highest tolerance to a short-term exposure to severe acid stress. Conclusion Chronic exposure to acidic conditions had a pervasive impact on Daphnia's physiology including acid-base balance, extracellular PCO2, circulation and ventilation, and energy metabolism. Compensatory changes in extracellular non-bicarbonate buffering capacity and the improved tolerance to severe acid stress indicated the activation of defense mechanisms which may result from gene-expression mediated adjustments in hemolymph buffer proteins and in epithelial properties. Mechanistic analyses of the interdependence between extracellular acid-base balance and CO2 transport

  6. Arachidonic acid reduces the stress response of gilthead seabream Sparus aurata L.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Nixon, O.; Wendelaar Bonga, S.E.

    2004-01-01

    In this study the influence of the dietary level of the fatty acid arachidonic acid (ArA, 20:4n-6) was determined on the acute stress response and osmoregulation of adult gilthead seabream Sparus aurata L. Seabream were fed a diet containing either 0.9% or 2.4% of total fatty acids as ArA for 18 day

  7. Effect of Pre-Stressing on the Acid-Stress Response in Bifidobacterium Revealed Using Proteomic and Physiological Approaches.

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    Junhua Jin

    Full Text Available Weak acid resistance limits the application of Bifidobacteria as a probiotic in food. The acid tolerance response (ATR, caused by pre-stressing cells at a sublethal pH, could improve the acid resistance of Bifidobacteria to subsequent acid stress. In this study, we used Bifidobacterium longum sub. longum BBMN68 to investigate the effect of the ATR on the acid stress response (ASR, and compared the difference between the ATR and the ASR by analyzing the two-dimensional-PAGE protein profiles and performing physiological tests. The results revealed that a greater abundance of proteins involved in carbohydrate metabolism and protein protection was present after the ASR than after the ATR in Bifidobacterium. Pre-stressing cells increased the abundance of proteins involved in energy production, amino acid metabolism, and peptidoglycan synthesis during the ASR of Bifidobacterium. Moreover, after the ASR, the content of ATP, NH3, thiols, and peptidoglycan, the activity of H+-ATPase, and the maintenance of the intracellular pH in the pre-stressed Bifidobacterium cells was significantly higher than in the uninduced cells. These results provide the first explanation as to why the resistance of Bifidobacterium to acid stress improved after pre-stressing.

  8. Glutathione is involved in physiological response of Candida utilis to acid stress.

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    Wang, Da-Hui; Zhang, Jun-Li; Dong, Ying-Ying; Wei, Gong-Yuan; Qi, Bin

    2015-12-01

    Candida utilis often encounters an acid stress environment when hexose and pentose are metabolized to produce acidic bio-based materials. In order to reveal the physiological role of glutathione (GSH) in the response of cells of this industrial yeast to acid stress, an efficient GSH-producing strain of C. utilis CCTCC M 209298 and its mutants deficient in GSH biosynthesis, C. utilis Δgsh1 and Δgsh2, were used in this study. A long-term mild acid challenge (pH 3.5 for 6 h) and a short-term severe acid challenge (pH 1.5 for 2 h) were conducted at 18 h during batch culture of the yeast to generate acid stress conditions. Differences in the physiological performances among the three strains under acid stress were analyzed in terms of GSH biosynthesis and distribution; intracellular pH; activities of γ-glutamylcysteine synthetase, catalase, and superoxide dismutase; intracellular ATP level; and ATP/ADP ratio. The intracellular GSH content of the yeast was found to be correlated with changes in physiological data, and a higher intracellular GSH content led to greater relief of cells to the acid stress, suggesting that GSH may be involved in protecting C. utilis against acid stress. Results presented in this manuscript not only increase our understanding of the impact of GSH on the physiology of C. utilis but also help us to comprehend the mechanism underlying the response to acid stress of eukaryotic microorganisms. PMID:26346268

  9. Physiological and transcriptional responses and cross protection of Lactobacillus plantarum ZDY2013 under acid stress.

    Science.gov (United States)

    Huang, Renhui; Pan, Mingfang; Wan, Cuixiang; Shah, Nagendra P; Tao, Xueying; Wei, Hua

    2016-02-01

    Acid tolerance responses (ATR) in Lactobacillus plantarum ZDY2013 were investigated at physiological and molecular levels. A comparison of composition of cell membrane fatty acids (CMFA) between acid-challenged and unchallenged cells showed that acid adaptation evoked a significantly higher percentage of saturated fatty acids and cyclopropane fatty acids in acid-challenged than in unchallenged cells. In addition, reverse transcription-quantitative PCR analysis in acid-adapted cells at different pH values (ranging from 3.0 to 4.0) indicated that several genes were differently regulated, including those related to proton pumps, amino acid metabolism, sugar metabolism, and class I and class III stress response pathways. Expression of genes involved in fatty acid synthesis and production of alkali was significantly upregulated. Upon exposure to pH 4.5 for 2 h, a higher survival rate (higher viable cell count) of Lactobacillus plantarum ZDY2013 was achieved following an additional challenge to 40 mM hydrogen peroxide for 60 min, but no difference in survival rate of cells was found with further challenge to heat, ethanol, or salt. Therefore, we concluded that the physiological and metabolic changes of acid-treated cells of Lactobacillus plantarum ZDY2013 help the cells resist damage caused by acid, and further initiated global response signals to bring the whole cell into a state of defense to other stress factors, especially hydrogen peroxide.

  10. Microarray Analysis of Transcriptional Responses to Abscisic Acid and Salt Stress in Arabidopsis thaliana

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    Yucheng Wang

    2013-05-01

    Full Text Available Abscisic acid (ABA plays a crucial role in plant responses to abiotic stress. To investigate differences in plant responses to salt and ABA stimulus, differences in gene expression in Arabidopsis in response to salt and ABA were compared using an Agilent oligo microarray. A total of 144 and 139 genes were significantly up- and downregulated, respectively, under NaCl stress, while 406 and 381 genes were significantly up- and downregulated, respectively, under ABA stress conditions. In addition, 31 genes were upregulated by both NaCl and ABA stresses, and 23 genes were downregulated by these stressors, suggesting that these genes may play similar roles in plant responses to salt and ABA stress. Gene ontology (GO analysis revealed four subgroups of genes, including genes in the GO categories “Molecular transducer activity”, “Growth”, “Biological adhesion” and “Pigmentation”, which were expressed in response to ABA stress but not NaCl stress. In addition, genes that play specific roles during salt or ABA stress were identified. Our results may help elucidate differences in the response of plants to salt and ABA stress.

  11. Good and bad protons: genetic aspects of acidity stress responses in plants.

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    Shavrukov, Yuri; Hirai, Yoshihiko

    2016-01-01

    Physiological aspects of acidity stress in plants (synonymous with H(+) rhizotoxicity or low-pH stress) have long been a focus of research, in particular with respect to acidic soils where aluminium and H(+) rhizotoxicities often co-occur. However, toxic H(+) and Al(3+) elicit different response mechanisms in plants, and it is important to consider their effects separately. The primary aim of this review was to provide the current state of knowledge regarding the genetics of the specific reactions to low-pH stress in growing plants. A comparison of the results gleaned from quantitative trait loci analysis and global transcriptome profiling of plants in response to high proton concentrations revealed a two-stage genetic response: (i) in the short-term, proton pump H(+)-ATPases present the first barrier in root cells, allocating an excess of H(+) into either the apoplast or vacuole; the ensuing defence signaling system involves auxin, salicylic acid, and methyl jasmonate, which subsequently initiate expression of STOP and DREB transcription factors as well as chaperone ROF; (2) the long-term response includes other genes, such as alternative oxidase and type II NAD(P)H dehydrogenase, which act to detoxify dangerous reactive oxygen species in mitochondria, and help plants better manage the stress. A range of transporter genes including those for nitrate (NTR1), malate (ALMT1), and heavy metals are often up-regulated by H(+) rhizotoxicity. Expansins, cell-wall-related genes, the γ-aminobutyric acid shunt and biochemical pH-stat genes also reflect changes in cell metabolism and biochemistry in acidic conditions. However, the genetics underlying the acidity stress response of plants is complicated and only fragmentally understood.

  12. Docosahexaenoic Acid Ameliorates Fructose-Induced Hepatic Steatosis Involving ER Stress Response in Primary Mouse Hepatocytes

    OpenAIRE

    Jinying Zheng; Chuan Peng; Yanbiao Ai; Heng Wang; Xiaoqiu Xiao; Jibin Li

    2016-01-01

    The increase in fructose consumption is considered to be a risk factor for developing nonalcoholic fatty liver disease (NAFLD). We investigated the effects of docosahexaenoic acid (DHA) on hepatic lipid metabolism in fructose-treated primary mouse hepatocytes, and the changes of Endoplasmic reticulum (ER) stress pathways in response to DHA treatment. The hepatocytes were treated with fructose, DHA, fructose plus DHA, tunicamycin (TM) or fructose plus 4-phenylbutyric acid (PBA) for 24 h. Intra...

  13. Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid

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    Sergio eGiannattasio

    2013-02-01

    Full Text Available Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications.

  14. Abscisic Acid-mediated Epigenetic Processes in Plant Development and Stress Responses

    Institute of Scientific and Technical Information of China (English)

    Viswanathan Chinnusamy; Zhizhong Gong; Jian-Kang Zhu

    2008-01-01

    Abscisic acid (ABA) regulates diverse plant processes, growth and development under non-stress conditions and plays a pivotal role in abiotic stress tolerance. Although ABA-regulated genetic processes are well known, recent discoveries reveal that epigenetic processes are an integral part of ABA-regulated processes. Epigenetic mechanisms, namely, histone modifications and cytosine DNA methylation-induced modification of genome give rise to epigenomes, which add diversity and complexity to the genome of organisms. Histone monoubiquitination appears to regulate ABA levels in developing seeds through histone H2B monoubiquitination. ABA and H2B ubiquitination dependent chromatin remodeling regulate seed dormancy. Transcription factor networks necessary for seed maturation are repressed by histone deacetylases (HDACs)-dependent and PICKLE chromatin remodeling complexes (CRCs), whereas ABA induces the expression of these genes directly or through repression of HDACs. Abiotic stress-induced ABA regulates stomatal response and stress-responsive gene expression through HDACs and HOS15-dependent histone deacetylation, as well as through the ATP-dependent SWITCH/SUCROSE NONFERMENTING CRC. ABA also probably regulates the abiotic stress response through DNA methylation and short interfering RNA pathways. Further studies on ABA-regulated spigenome will be of immense use to understand the plant development, stress adaptation and stress memory.

  15. Water stress responses of tomato mutants impaired in hormone biosynthesis reveal abscisic acid, jasmonic acid and salicylic acid interactions

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    Valeria eMuñoz

    2015-11-01

    Full Text Available To investigate the putative crosstalk between JA and ABA in Solanum lycopersicum plants in response to drought, suppressor of prosystemin-mediated responses2 (spr2, JA-deficient and flacca (flc, ABA-deficient mutants together with the naphthalene/salicylate hydroxylase (NahG transgenic (SA-deficient line were used. Hormone profiling and gene expression of key enzymes in ABA, JA and SA biosynthesis were analyzed during early stages of drought. ABA accumulation was comparable in spr2 and wild type (WT plants whereas expression of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1 and NCED2 was different, implying a compensation mechanism between NCED genes and an organ-specific regulation of NCED1 expression. JA levels and 12-oxo-phytodienoic acid reductase 3 (OPR3 expression in flc plants suggest that ABA regulates the induction of the OPR3 gene in roots. By contrast, ABA treatment to flc plants leads to a reduction of JA and SA contents. Furthermore, different pattern of SA accumulation (and expression of isochorismate synthase and phenylalanine ammonia lyase 1 was observed between WT seedlings and mutants, suggesting that SA plays an important role on the early response of tomato plants to drought and also that JA and ABA modulate its biosynthesis. Finally, hormone profiling in spr2 and NahG plants indicate a crosstalk between JA and SA that could enhance tolerance of tomato to water stress.

  16. Water Stress Responses of Tomato Mutants Impaired in Hormone Biosynthesis Reveal Abscisic Acid, Jasmonic Acid and Salicylic Acid Interactions.

    Science.gov (United States)

    Muñoz-Espinoza, Valeria A; López-Climent, María F; Casaretto, José A; Gómez-Cadenas, Aurelio

    2015-01-01

    To investigate the putative crosstalk between JA and ABA in Solanum lycopersicum plants in response to drought, suppressor of prosystemin-mediated responses2 (spr2, JA-deficient) and flacca (flc, ABA-deficient) mutants together with the naphthalene/salicylate hydroxylase (NahG) transgenic (SA-deficient) line were used. Hormone profiling and gene expression of key enzymes in ABA, JA and SA biosynthesis were analyzed during early stages of drought. ABA accumulation was comparable in spr2 and wild type (WT) plants whereas expression of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1) and NCED2 was different, implying a compensation mechanism between NCED genes and an organ-specific regulation of NCED1 expression. JA levels and 12-oxo-phytodienoic acid reductase 3 (OPR3) expression in flc plants suggest that ABA regulates the induction of the OPR3 gene in roots. By contrast, ABA treatment to flc plants leads to a reduction of JA and SA contents. Furthermore, different pattern of SA accumulation (and expression of isochorismate synthase and phenylalanine ammonia lyase 1) was observed between WT seedlings and mutants, suggesting that SA plays an important role on the early response of tomato plants to drought and also that JA and ABA modulate its biosynthesis. Finally, hormone profiling in spr2 and NahG plants indicate a crosstalk between JA and SA that could enhance tolerance of tomato to water stress. PMID:26635826

  17. Jasmonic acid interacts with abscisic acid to regulate plant responses to water stress conditions

    OpenAIRE

    de Ollas, Carlos; Arbona, Vicent; Gómez-Cadenas, Aurelio

    2015-01-01

    Phytohormones are key players in signaling environmental stress conditions. Hormone profiling together with proline accumulation were studied in leaves and roots of different mutant lines of Arabidopsis. Regulation of proline accumulation in this system seems complex and JA-deficient (jar1-1) and JA-insensitive (jai1) lines accumulating high levels of proline despite their very low ABA levels seems to discard an ABA-dependent response. However, the pattern of proline accumulation in jai1 seed...

  18. Functional annotation of the transcriptome of Sorghum bicolor in response to osmotic stress and abscisic acid

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    Kumari Sunita

    2011-10-01

    Full Text Available Abstract Background Higher plants exhibit remarkable phenotypic plasticity allowing them to adapt to an extensive range of environmental conditions. Sorghum is a cereal crop that exhibits exceptional tolerance to adverse conditions, in particular, water-limiting environments. This study utilized next generation sequencing (NGS technology to examine the transcriptome of sorghum plants challenged with osmotic stress and exogenous abscisic acid (ABA in order to elucidate genes and gene networks that contribute to sorghum's tolerance to water-limiting environments with a long-term aim of developing strategies to improve plant productivity under drought. Results RNA-Seq results revealed transcriptional activity of 28,335 unique genes from sorghum root and shoot tissues subjected to polyethylene glycol (PEG-induced osmotic stress or exogenous ABA. Differential gene expression analyses in response to osmotic stress and ABA revealed a strong interplay among various metabolic pathways including abscisic acid and 13-lipoxygenase, salicylic acid, jasmonic acid, and plant defense pathways. Transcription factor analysis indicated that groups of genes may be co-regulated by similar regulatory sequences to which the expressed transcription factors bind. We successfully exploited the data presented here in conjunction with published transcriptome analyses for rice, maize, and Arabidopsis to discover more than 50 differentially expressed, drought-responsive gene orthologs for which no function had been previously ascribed. Conclusions The present study provides an initial assemblage of sorghum genes and gene networks regulated by osmotic stress and hormonal treatment. We are providing an RNA-Seq data set and an initial collection of transcription factors, which offer a preliminary look into the cascade of global gene expression patterns that arise in a drought tolerant crop subjected to abiotic stress. These resources will allow scientists to query gene

  19. Effects of diets high in unsaturated Fatty acids on socially induced stress responses in Guinea pigs.

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    Matthias Nemeth

    Full Text Available Unsaturated fatty acids (UFAs, such as omega-3 and omega-6 poly- and omega-9 monounsaturated fatty acids are important nutrients and major components of neuronal cell membranes. They play a major role in modulating brain functions and physiology and may therefore diminish behavioral and physiological stress reactions in corroboration with decreased cortisol concentrations. Functionally, cortisol itself can modulate several behaviors and also the fatty acid metabolism in the long term. But only little is known about the behavioral and physiological influences of dietary UFAs in a social group, where individuals are regularly exposed to stressful situations. Therefore, the aim of this study was to determine the effects of dietary UFAs on saliva cortisol concentrations and behavioral responses in socially confronted guinea pigs. Three groups of animals were additionally supplemented with 500 mg chia seeds (high in omega-3, walnuts (high in omega-6, or peanuts (high in omega-9 per kg bodyweight each day and compared to a control group. During social confrontation saliva cortisol concentrations significantly increased in all groups, which was accompanied by a loss in bodyweight. However, cortisol levels remained lower in the chia and walnut groups compared to controls. Additionally, the walnut group displayed significantly increased locomotion, while no differences between groups were detected in socio-positive, sexual, or aggressive behaviors. Total plasma omega-3, omega-6, and omega-9 fatty acids were significantly increased in the corresponding groups, due to the dietary supplementations. However, a significant decrease in plasma omega-3 and an increase in plasma n-6 fatty acids were detected in the chia group when comparing the measurements before and after social confrontation. We conclude that both omega-3 and omega-6 polyunsaturated fatty acids can diminish behavioral and physiological stress responses to the social environment, enabling

  20. Changes in fatty acid composition in the giant clam Tridacna maxima in response to thermal stress

    Science.gov (United States)

    Dubousquet, Vaimiti; Gros, Emmanuelle; Berteaux-Lecellier, Véronique; Viguier, Bruno; Raharivelomanana, Phila; Bertrand, Cédric; Lecellier, Gaël J.

    2016-01-01

    ABSTRACT Temperature can modify membrane fluidity and thus affects cellular functions and physiological activities. This study examines lipid remodelling in the marine symbiotic organism, Tridacna maxima, during a time series of induced thermal stress, with an emphasis on the morphology of their symbiont Symbiodinium. First, we show that the French Polynesian giant clams harbour an important proportion of saturated fatty acids (SFA), which reflects their tropical location. Second, in contrast to most marine organisms, the total lipid content in giant clams remained constant under stress, though some changes in their composition were shown. Third, the stress-induced changes in fatty acid (FA) diversity were accompanied by an upregulation of genes involved in lipids and ROS pathways. Finally, our microscopic analysis revealed that for the giant clam's symbiont, Symbiodinium, thermal stress led to two sequential cell death processes. Our data suggests that the degradation of Symbiodinium cells could provide an additional source of energy to T. maxima in response to heat stress. PMID:27543058

  1. Pseudomonas putida response in membrane bioreactors under salicylic acid-induced stress conditions.

    Science.gov (United States)

    Collado, Sergio; Rosas, Irene; González, Elena; Gutierrez-Lavin, Antonio; Diaz, Mario

    2014-02-28

    Starvation and changing feeding conditions are frequently characteristics of wastewater treatment plants. They are typical causes of unsteady-state operation of biological systems and provoke cellular stress. The response of a membrane bioreactor functioning under feed-induced stress conditions is studied here. In order to simplify and considerably amplify the response to stress and to obtain a reference model, a pure culture of Pseudomonas putida was selected instead of an activated sludge and a sole substrate (salicylic acid) was employed. The system degraded salicylic acid at 100-1100mg/L with a high level of efficiency, showed rapid acclimation without substrate or product inhibition phenomena and good stability in response to unsteady states caused by feed variations. Under starvation conditions, specific degradation rates of around 15mg/gh were achieved during the adaptation of the biomass to the new conditions and no biofilm formation was observed during the first days of experimentation using an initial substrate to microorganisms ratio lower than 0.1. When substrate was added to the reactor as pulses resulting in rapidly changing concentrations, P. putida growth was observed only for substrate to microorganism ratios higher than 0.6, with a maximum YX/S of 0.5g/g. Biofilm development under changing feeding conditions was fast, biomass detachment only being significant for biomass concentrations on the membrane surface that were higher than 16g/m(2).

  2. RESPONSE OF SPECKLED SPUR-FLOWER TO SALINITY STRESS AND SALICYLIC ACID TREATMENT

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    Piotr Salachna

    2015-11-01

    Full Text Available One of the limitations to using ornamental plants in green areas is too high salinity and alkalization of the soil. The adverse effect of salinity on plant growth and development may be effectively reduced by application of salicylic acid. Plectranthus ciliatus is an attractive bed plant with ornamental leaves, recommended for growing in containers, hanging baskets, or sunny borders. The aim of this study was to investigate the response of P. ciliatus to salicylic acid and calcium chloride. The plants were grown in pots in a glasshouse and were sprayed with solution of 0.5 mM salicylic acid and watered with 200 mM calcium chloride. The application of salicylic acid resulted in an increased weight of the aboveground parts, higher stomatal conductance and leaf greenness index and enhanced leaf content of nitrogen, potassium, iron and zinc. Salinity-exposed plants were characterized by reduced weight, stomatal conductance and leaf greenness index. Salt stress caused also a drop in leaf content of nitrogen, potassium and iron, and an increase in calcium, sodium, chlorine, copper and manganese concentration. Salicylic acid seemed to relieve salinity-mediated plant stress.

  3. Role of abscisic acid (aba) in modulating the responses of two apple rootstocks to drought stress

    International Nuclear Information System (INIS)

    Drought stress is considered as the main limiting factor for apple (Malus domestica L.) production in some semi-arid areas of China. In this study, we investigated the modulation role of abscisic acid (ABA) and fluridone (ABA synthesis inhibitor) on water relations and antioxidant enzyme system in 2-year-old seedlings of two apple rootstocks i.e. Malus sieversii (Ledeb.) Roem. (MS) and Malus hupehensis (Pamp.) Rehd. (MH). Drought stress induced ion leakage, accumulation of malondiadehyde (MDA) and decreases in leaf water potential and relative water content (RWC) in both rootstocks, which were significantly alleviated by exogenous ABA application. Drought stress also induced markedly increases in endogenous ABA content and activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reductase (GR), to a greater magnitude in MS as compared to MH rootstock. Concentration of 100 mol/L and 50 mol/L ABA had the most positive effects on drought-stressed rootstocks of MS and MH, respectively. Spraying optimum exogenous ABA contributed to enhancement in most of the above antioxidant enzymes activities but reduction in content of MDA and maintained the appropriate leaf water potential and RWC in both rootstocks. Pretreatment with fluridone aggravated ion leakage and the accumulation of MDA in two apple rootstocks under drought stress, which was overcome by exogenous ABA application to some extent. In conclusion, the endogenous ABA was probably involved in the regulation of two apple rootstocks in responses to drought stress. (author)

  4. Gene-related strain variation of Staphylococcus aureus for homologous resistance response to acid stress.

    Science.gov (United States)

    Lee, Soomin; Ahn, Sooyeon; Lee, Heeyoung; Kim, Won-Il; Kim, Hwang-Yong; Ryu, Jae-Gee; Kim, Se-Ri; Choi, Kyoung-Hee; Yoon, Yohan

    2014-10-01

    This study investigated the effect of adaptation of Staphylococcus aureus strains to the acidic condition of tomato in response to environmental stresses, such as heat and acid. S. aureus ATCC 13565, ATCC 14458, ATCC 23235, ATCC 27664, and NCCP10826 habituated in tomato extract at 35°C for 24 h were inoculated in tryptic soy broth. The culture suspensions were then subjected to heat challenge or acid challenge at 60°C and pH 3.0, respectively, for 60 min. In addition, transcriptional analysis using quantitative real-time PCR was performed to evaluate the expression level of acid-shock genes, such as clpB, zwf, nuoF, and gnd, from five S. aureus strains after the acid habituation of strains in tomato at 35°C for 15 min and 60 min in comparison with that of the nonhabituated strains. In comparison with the nonhabituated strains, the five tomato-habituated S. aureus strains did not show cross protection to heat, but tomato-habituated S. aureus ATCC 23235 showed acid resistance. In quantitative real-time-PCR analysis, the relative expression levels of acid-shock genes (clpB, zwf, nuoF, and gnd) were increased the most in S. aureus ATCC 23235 after 60 min of tomato habituation, but there was little difference in the expression levels among the five S. aureus strains after 15 min of tomato habituation. These results indicate that the variation of acid resistance of S. aureus is related to the expression of acid-shock genes during acid habituation. PMID:25285500

  5. Pseudomonas putida response in membrane bioreactors under salicylic acid-induced stress conditions

    International Nuclear Information System (INIS)

    Highlights: • MBR under feed-induced stress conditions: starvation and changing feeding conditions. • High capacity of MBR to withstand high variations in feed loads. • Slow biofilm formation under starvation conditions during the first days. • Observed growth of P. putida for substrate to microorganism ratio higher than 0.6 g/g. • Maximum specific growth rate and growth yield values of around 37.5 h−1 and 0.5 g/g. - Abstract: Starvation and changing feeding conditions are frequently characteristics of wastewater treatment plants. They are typical causes of unsteady-state operation of biological systems and provoke cellular stress. The response of a membrane bioreactor functioning under feed-induced stress conditions is studied here. In order to simplify and considerably amplify the response to stress and to obtain a reference model, a pure culture of Pseudomonas putida was selected instead of an activated sludge and a sole substrate (salicylic acid) was employed. The system degraded salicylic acid at 100–1100 mg/L with a high level of efficiency, showed rapid acclimation without substrate or product inhibition phenomena and good stability in response to unsteady states caused by feed variations. Under starvation conditions, specific degradation rates of around 15 mg/g h were achieved during the adaptation of the biomass to the new conditions and no biofilm formation was observed during the first days of experimentation using an initial substrate to microorganisms ratio lower than 0.1. When substrate was added to the reactor as pulses resulting in rapidly changing concentrations, P. putida growth was observed only for substrate to microorganism ratios higher than 0.6, with a maximum YX/S of 0.5 g/g. Biofilm development under changing feeding conditions was fast, biomass detachment only being significant for biomass concentrations on the membrane surface that were higher than 16 g/m2

  6. Pseudomonas putida response in membrane bioreactors under salicylic acid-induced stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Sergio; Rosas, Irene; González, Elena; Gutierrez-Lavin, Antonio; Diaz, Mario, E-mail: mariodiaz@uniovi.es

    2014-02-01

    Highlights: • MBR under feed-induced stress conditions: starvation and changing feeding conditions. • High capacity of MBR to withstand high variations in feed loads. • Slow biofilm formation under starvation conditions during the first days. • Observed growth of P. putida for substrate to microorganism ratio higher than 0.6 g/g. • Maximum specific growth rate and growth yield values of around 37.5 h{sup −1} and 0.5 g/g. - Abstract: Starvation and changing feeding conditions are frequently characteristics of wastewater treatment plants. They are typical causes of unsteady-state operation of biological systems and provoke cellular stress. The response of a membrane bioreactor functioning under feed-induced stress conditions is studied here. In order to simplify and considerably amplify the response to stress and to obtain a reference model, a pure culture of Pseudomonas putida was selected instead of an activated sludge and a sole substrate (salicylic acid) was employed. The system degraded salicylic acid at 100–1100 mg/L with a high level of efficiency, showed rapid acclimation without substrate or product inhibition phenomena and good stability in response to unsteady states caused by feed variations. Under starvation conditions, specific degradation rates of around 15 mg/g h were achieved during the adaptation of the biomass to the new conditions and no biofilm formation was observed during the first days of experimentation using an initial substrate to microorganisms ratio lower than 0.1. When substrate was added to the reactor as pulses resulting in rapidly changing concentrations, P. putida growth was observed only for substrate to microorganism ratios higher than 0.6, with a maximum Y{sub X/S} of 0.5 g/g. Biofilm development under changing feeding conditions was fast, biomass detachment only being significant for biomass concentrations on the membrane surface that were higher than 16 g/m{sup 2}.

  7. The Physiological and Molecular Responses of Arabidopsis thaliana to the Stress of Oxalic Acid

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-ting; LIN Jie; SHAO Xue-feng; OU Xiao-ming; WANG Zong-hua; LU Guo-dong

    2009-01-01

    Many fungal phytopathogens can secrete oxalic acid (OA), which is the crucial pathogenic determinant and plays important roles in pathogenicity and virulence of pathogen during infection process. However, how plants respond to OA stress still needs further characterization. In this study, we observed the physiological and molecular responses of Arabidopsis thaliana to OA stress. The leaves of 6-wk-old A. thaliana were sprayed with OA and distilled water respectively, and 0, 2, 4, 8, 12, and 24 h later, the leaves were collected and the contents of MDA, H2O2, and GSH, and the activities of CAT, SOD, and POD were determined and the expressions of PR1 and PDF1.2 were also studied. Under the stress of 30 mmol L-1 OA, SOD activity was first enhanced to reduce the accumulation of O2-. But immediately, POD, CAT, and GSH all decreased extremely resulting in the accumulation of H2O2, and the MDA content increased 24 h later. GSH activity was enhanced significantly at 24 h after OA used. However, H2O2 wasn't eliminated at the same time, suggesting that the activity inhibitions of POD and CAT might be the reasons that caused Arabidopsis cells' impairment under OA stress. RT-PCR results indicated that PDF1.2, a marker gene of the JA/ET signaling was significantly induced; PR1, an indicator gene in SA signaling, was slighlty induced from 8 to 12 h after OA stress. In conclusion, Arabidopsis may recruit metabolism of reactive oxygen, both JA/ET and SA signaling pathways to respond to OA stress. These results will facilitate our further understanding the mechanisms of plant response to OA and OA-dependent fungal infection.

  8. Physiological responses of needles of Pinus massoniana elite families to phosphorus stress in acid soil

    Institute of Scientific and Technical Information of China (English)

    HE You-lan; LIU Ai-qin; Mulualem Tigabu; WUPeng-fei; MA Xiang-qing; WANG Chen; Per Christer Oden

    2013-01-01

    Pinus massoniana Lamb.is a major timber species widely planted in the South China,where the soil is acidic and deficient in phosphorus (P) due to fixation by aluminum and iron.Understanding the physiological responses to rhizospheric insoluble P is essential for enhancing plantation productivity.Thus,a sand culture experiment was conducted with four levels of P treatment (0,5,20 g insoluble P and 10 g soluble P),and 11 P.massoniana elite families.Physiological responses were measured after two months of stress.Compared to the normal soluble P treatment,the insoluble P treatment significantly reduced the proline content and the APase activity in the needles,while it significantly increased the catalase activity by 1.3-fold and malondialdehyde content by 1.2-fold.Soluble protein content was unaffected by the treatments,but chlorophyll content was significantly lower in P-deprived treatment compared with soluble and insoluble P treatments.These physiological responses also exhibited highly significant variation among families (p < 0.01).The findings suggest that increased catalase activities in the presence of insoluble P might be involved in the activation of an anti-oxidation defense mechanism that scavenges the reactive oxygen species elicited by the stress.And this response has a strong genetic control that can be exploited to identify desirable genotypes.

  9. Salicylic acid induces differential antioxidant response in spring maize under high temperature stress.

    Science.gov (United States)

    Khanna, Palak; Kaur, Kamaljit; Gupta, Anil K

    2016-06-01

    High temperature is one of the important stress factors that affect crops in tropical countries. Plants do evolve or adopt different mechanisms to overcome such stress for survival. It is an interesting subject and has attracted many researchers to work upon. Here, we studied the effect of salicylic acid (SA) on seedling growth and antioxidative defense system in two spring maize (Zea mays L.) genotypes viz., CML-32 (relatively heat tolerant) and LM-11 (relatively heat susceptible), under high temperature stress. High temperature induced greater reduction in dry biomass of LM-1 1 seedlings as compared to those of CML-32. There was a parallel increase in ascorbate peroxidase and glutathione reductase activities in the roots of CML-32 seedlings. However, the activities of catalase and superoxide dismutase decreased and the contents of H202, proline and malonaldialdehyde (MDA) increased in seedlings of both the genotypes. Application of SA (400 µM) led to increased dry biomass in heat stressed CML-32 seedlings. It improved the efficiency of Halliwell-Asada pathway in roots of CML-32 seedlings as was evidenced by the enhanced ascorbate peroxidase and glutathione reductase activities. The activities of catalase and superoxide dismutase increased in both the tissues of LM-11 seedlings, whereas in CML-32, it was only in shoots, after SA application. Peroxidase activity increased in SA treated seedlings of both the genotypes, though the increase was comparatively higher in CML-32. The contents of H₂O₂ and MDA decreased and that of proline increased in SA treated seedlings of both the genotypes, under stress conditions. It may be concluded that SA induced differential antioxidant response by upregulating Halliwell-Asada pathway in roots and attaining high POX activity in both the tissues of CML-32 seedlings, under high temperature stress. PMID:27468465

  10. Dietary fatty acids and the stress response of fish : arachidonic acid in seabream and tilapia

    NARCIS (Netherlands)

    Anholt, Rogier Daniël van

    2004-01-01

    A key factor in the production of fish in commercial aquaculture is the optimization of the artificial diets, not only to achieve optimal growth, but also to maximize fish health. Evidence is accumulating that dietary lipids, particularly the fatty acid composition, can have a direct effect on the f

  11. The osmotic stress response of split influenza vaccine particles in an acidic environment

    OpenAIRE

    Choi, Hyo-Jick; Kim, Min-Chul; Kang, Sang-Moo; Montemagno, Carlo D.

    2013-01-01

    Oral influenza vaccine provides an efficient means of preventing seasonal and pandemic disease. In this work, the stability of envelope-type split influenza vaccine particles in acidic environments has been investigated. Owing to the fact that hyper-osmotic stress can significantly affect lipid assembly of vaccine, osmotic stress-induced morphological change of split vaccine particles, in conjunction with structural change of antigenic proteins, was investigated by the use of stopped-flow lig...

  12. Movement of abscisic acid into the apoplast in response to water stress in Xanthium strumarium L

    Energy Technology Data Exchange (ETDEWEB)

    Cornish, K.; Zeevaart, J.A.D.

    1985-07-01

    The effect of water stress on the redistribution of abscisic acid (ABA) in mature leaves of Xanthium strumarium L. was investigated using a pressure dehydration technique. In both turgid and stressed leaves, the ABA in the xylem exudate, the apoplastic ABA, increased before bulk leaf stress-induced ABA accumulation began. In the initially turgid leaves, the ABA level remained constant in both the apoplast and the leaf as a whole until wilting symptoms appeared. Following turgor loss, sufficient quantities of ABA moved into the apoplast to stimulate stomatal closure. Thus, the initial increase of apoplastic ABA may be relevant to the rapid stomatal closure seen in stressed leaves before their bulk leaf ABA levels rise. Following recovery from water stress, elevated levels of ABA remained in the apoplast after the bulk leaf contents had returned to their prestress values. This apoplastic ABA may retard stomatal reopening during the initial recovery period. 32 references, 5 figures.

  13. H2O2 mediates the crosstalk of brassinosteroid and abscisic acid in tomato responses to heat and oxidative stresses

    OpenAIRE

    Zhou, Jie; Wang, Jian; Li, Xin; Xia, Xiao-Jian; Zhou, Yan-Hong; Shi, Kai; Chen, Zhixiang; Yu, Jing-Quan

    2014-01-01

    The production of H2O2 is critical for brassinosteroid (BR)- and abscisic acid (ABA)-induced stress tolerance in plants. In this study, the relationship between BR and ABA in the induction of H2O2 production and their roles in response to heat and paraquat (PQ) oxidative stresses were studied in tomato. Both BR and ABA induced increases in RBOH1 gene expression, NADPH oxidase activity, apoplastic H2O2 accumulation, and heat and PQ stress tolerance in wild-type plants. BR could only induced tr...

  14. Hormonal and Hydroxycinnamic Acids Profiles in Banana Leaves in Response to Various Periods of Water Stress

    Directory of Open Access Journals (Sweden)

    Jalel Mahouachi

    2014-01-01

    Full Text Available The pattern of change in the endogenous levels of several plant hormones and hydroxycinnamic acids in addition to growth and photosynthetic performance was investigated in banana plants (Musa acuminata cv. “Grand Nain” subjected to various cycles of drought. Water stress was imposed by withholding irrigation for six periods with subsequent rehydration. Data showed an increase in abscisic acid (ABA and indole-3-acetic acid (IAA levels, a transient increase in salicylic acid (SA concentration, and no changes in jasmonic acid (JA after each period of drought. Moreover, the levels of ferulic (FA and cinnamic acids (CA were increased, and plant growth and leaf gas exchange parameters were decreased by drought conditions. Overall, data suggest an involvement of hormones and hydroxycinnamic acids in plant avoidance of tissue dehydration. The increase in IAA concentration might alleviate the senescence of survival leaves and maintained cell elongation, and the accumulation of FA and CA could play a key role as a mechanism of photoprotection through leaf folding, contributing to the effect of ABA on inducing stomatal closure. Data also suggest that the role of SA similarly to JA might be limited to a transient and rapid increase at the onset of the first period of stress.

  15. Adaptive response of Rhodococcus opacus PWD4 to salt and phenolic stress on the level of mycolic acids.

    Science.gov (United States)

    de Carvalho, Carla C C R; Fischer, Martin A; Kirsten, Sandra; Würz, Birgit; Wick, Lukas Y; Heipieper, Hermann J

    2016-12-01

    Mycolata form a group of Gram-positive bacteria with unique cell envelope structures that are known for their high tolerance against antibiotics and both aromatic and aliphatic hydrocarbons. An important part of the unique surface structure of the mycolata is the presence of long chain α-alkyl-β-hydroxy fatty acids, the mycolic acids. In order to investigate the adaptive changes in the mycolic acid composition, we investigated the composition of mycolic acids during the response both to osmotic stress caused by NaCl and to 4-chlorophenol in Rhodococcus opacus PWD4. This bacterium was chosen as it is known to adapt to different kinds of stresses. In addition, it is a potential biocatalyst in bioremediation as well as for biotechnological applications. In the present study, cells of R. opacus PWD4, grown in liquid cultures, responded to toxic concentrations of NaCl by increasing the ratio between mycolic acids and membrane phospholipid fatty acids (MA/PLFA-ratio). Cells reacted to both NaCl and 4-chlorophenol by decreasing both the average chain length and the unsaturation index of their mycolic acids. These changes in mycolic acid composition correlated with increases in cell surface hydrophobicity and saturation of membrane fatty acids, demonstrating the relation between mycolic acid and phospholipid synthesis and their contribution to cell surface properties of R. opacus PWD4.

  16. Involvement of ethylene in gibberellic acid-induced sulfur assimilation, photosynthetic responses, and alleviation of cadmium stress in mustard.

    Science.gov (United States)

    Masood, Asim; Khan, M Iqbal R; Fatma, Mehar; Asgher, Mohd; Per, Tasir S; Khan, Nafees A

    2016-07-01

    The role of gibberellic acid (GA) or sulfur (S) in stimulation of photosynthesis is known. However, information on the involvement of ethylene in GA-induced photosynthetic responses and cadmium (Cd) tolerance is lacking. This work shows that ethylene is involved in S-assimilation, photosynthetic responses and alleviation of Cd stress by GA in mustard (Brassica juncea L.). Plants grown with 200 mg Cd kg(-1) soil were less responsive to ethylene despite high ethylene evolution and showed photosynthetic inhibition. Plants receiving 10 μM GA spraying plus 100 mg S kg(-1) soil supplementation exhibited increased S-assimilation and photosynthetic responses under Cd stress. Application of GA plus S decreased oxidative stress of plants grown with Cd and limited stress ethylene formation to the range suitable for promoting sulfur use efficiency (SUE), glutathione (GSH) production and photosynthesis. The role of ethylene in GA-induced S-assimilation and reversal of photosynthetic inhibition by Cd was substantiated by inhibiting ethylene biosynthesis with the use of aminoethoxyvinylglycine (AVG). The suppression of S-assimilation and photosynthetic responses by inhibiting ethylene in GA plus S treated plants under Cd stress indicated the involvement of ethylene in GA-induced S-assimilation and Cd stress alleviation. The outcome of the study is important to unravel the interaction between GA and ethylene and their role in Cd tolerance in plants. PMID:26998941

  17. Different response to acetic acid stress in Saccharomyces cerevisiae wild-type and l-ascorbic acid-producing strains.

    Science.gov (United States)

    Martani, Francesca; Fossati, Tiziana; Posteri, Riccardo; Signori, Lorenzo; Porro, Danilo; Branduardi, Paola

    2013-09-01

    Biotechnological processes are of increasing significance for industrial production of fine and bulk chemicals, including biofuels. Unfortunately, under operative conditions microorganisms meet multiple stresses, such as non-optimal pH, temperature, oxygenation and osmotic stress. Moreover, they have to face inhibitory compounds released during the pretreatment of lignocellulosic biomasses, which constitute the preferential substrate for second-generation processes. Inhibitors include furan derivatives, phenolic compounds and weak organic acids, among which acetic acid is one of the most abundant and detrimental for cells. They impair cellular metabolism and growth, reducing the productivity of the process: therefore, the development of robust cell factories with improved production rates and resistance is of crucial importance. Here we show that a yeast strain engineered to endogenously produce vitamin C exhibits an increased tolerance compared to the parental strain when exposed to acetic acid at moderately toxic concentrations, measured as viability on plates. Starting from this evidence, we investigated more deeply: (a) the nature and levels of reactive oxygen species (ROS); (b) the activation of enzymes that act directly as detoxifiers of reactive oxygen species, such as superoxide dismutase (SOD) and catalase, in parental and engineered strains during acetic acid stress. The data indicate that the engineered strain can better recover from stress by limiting ROS accumulation, independently from SOD activation. The engineered yeast can be proposed as a model for further investigating direct and indirect mechanism(s) by which an antioxidant can rescue cells from organic acid damage; moreover, these studies will possibly provide additional targets for further strain improvements.

  18. Different response to acetic acid stress in Saccharomyces cerevisiae wild-type and l-ascorbic acid-producing strains.

    Science.gov (United States)

    Martani, Francesca; Fossati, Tiziana; Posteri, Riccardo; Signori, Lorenzo; Porro, Danilo; Branduardi, Paola

    2013-09-01

    Biotechnological processes are of increasing significance for industrial production of fine and bulk chemicals, including biofuels. Unfortunately, under operative conditions microorganisms meet multiple stresses, such as non-optimal pH, temperature, oxygenation and osmotic stress. Moreover, they have to face inhibitory compounds released during the pretreatment of lignocellulosic biomasses, which constitute the preferential substrate for second-generation processes. Inhibitors include furan derivatives, phenolic compounds and weak organic acids, among which acetic acid is one of the most abundant and detrimental for cells. They impair cellular metabolism and growth, reducing the productivity of the process: therefore, the development of robust cell factories with improved production rates and resistance is of crucial importance. Here we show that a yeast strain engineered to endogenously produce vitamin C exhibits an increased tolerance compared to the parental strain when exposed to acetic acid at moderately toxic concentrations, measured as viability on plates. Starting from this evidence, we investigated more deeply: (a) the nature and levels of reactive oxygen species (ROS); (b) the activation of enzymes that act directly as detoxifiers of reactive oxygen species, such as superoxide dismutase (SOD) and catalase, in parental and engineered strains during acetic acid stress. The data indicate that the engineered strain can better recover from stress by limiting ROS accumulation, independently from SOD activation. The engineered yeast can be proposed as a model for further investigating direct and indirect mechanism(s) by which an antioxidant can rescue cells from organic acid damage; moreover, these studies will possibly provide additional targets for further strain improvements. PMID:23847041

  19. Arabidopsis cysteine-rich receptor-like kinase 45 functions in the responses to abscisic acid and abiotic stresses

    KAUST Repository

    Zhang, Xiujuan

    2013-06-01

    The phytohormone abscisic acid (ABA) regulates seed germination, plant growth and development, and response to abiotic stresses such as drought and salt stresses. Receptor-like kinases are well known signaling components that mediate plant responses to developmental and environmental stimuli. Here, we characterized the biological function of an ABA and stress-inducible cysteine-rich receptor-like protein kinase, CRK45, in ABA signaling in Arabidopsis thaliana. The crk45 mutant was less sensitive to ABA than the wild type during seed germination and early seedling development, whereas CRK45 overexpression plants were more sensitive to ABA compared to the wild type. Furthermore, overexpression of CRK45 led to hypersensitivity to salt and glucose inhibition of seed germination, whereas the crk45 mutant showed the opposite phenotypes. In addition, CRK45 overexpression plants had enhanced tolerance to drought. Gene expression analyses revealed that the expression of representative stress-responsive genes was significantly enhanced in CRK45 overexpression plants in response to salt stress. ABA biosynthetic genes such as NCED3,. 22NCED3, 9-Cis-Epoxycarotenoid Dioxygenase 3.NCED5,. 33NCED5, 9-Cis-Epoxycarotenoid Dioxygenase 5.ABA2,. 44ABA2, Abscisic Acid Deficient 2. and AAO355AAO3, Abscisic Aldehyde Oxidase 3. were also constitutively elevated in the CRK45 overexpression plants. We concluded that CRK45 plays an important role in ABA signaling that regulates Arabidopsis seeds germination, early seedling development and abiotic stresses response, by positively regulating ABA responses in these processes. © 2013 Elsevier Masson SAS.

  20. [The ABC of abscisic acid action in plant drought stress responses].

    Science.gov (United States)

    Leung, Jeffrey; Valon, Christiane; Moreau, Bertrand; Boeglin, Martin; Lefoulon, Cécile; Joshi-Saha, Archana; Chérel, Isabelle

    2012-01-01

    The combined daily consumption of fresh water ranges from 200 to 700 liters per capita per day in most developed countries, with about 70% being used for agricultural needs. Unlike other resources such as the different forms of energy, water has no other alternatives. With the looming prospect of global water crisis, the recent laudable success in deciphering the early steps in the signal transduction of the "stress hormone" abscisic acid (ABA) has ignited hopes that crops can be engineered with the capacity to maintain productivity while requiring less water input. Although ABA was first discovered in plants, it has resurfaced in the human brain (and many other non-plant organisms : sea sponge, some parasites, hydra to name a few), suggesting that its existence may be widespread. In humans, more amazingly, ABA has shown anti-inflammatory and antiviral properties. Even its receptors and key signaling intermediates have homologs in the human genome suggesting that evolution has re-fashioned these same proteins into new functional contexts. Thus, learning about the molecular mechanisms of ABA in action using the more flexible plant model will be likely beneficial to other organisms, and especially in human diseases, which is topical in the medical circle. ABA can accumulate up to 10 to 30-fold in plants under drought stress relative to unstressed conditions. The built up of the hormone then triggers diverse adaptive pathways permitting plants to withstand temporary bouts of water shortage. One favorite experimental model to unravel ABA signaling mechanisms in all of its intimate detail is based on the hormone's ability to elicit stomatal closure - a rapid cellular response of land plants to limit water loss through transpiration. Each microscopic stoma, or pore, is contoured by two specialized kidney-shaped cells called the guard cells. Because land plants are protected by a waxy cuticle impermeable to gas exchange, the stomatal pores are thus the primary portals for

  1. SaliCylic Acid-Altering Arabidopsis Mutants Response to Cd Stress

    Institute of Scientific and Technical Information of China (English)

    Lu; Tian; Liang; Wu

    2012-01-01

    To evaluate the role of endogenous SA in plant response to Cd stress,Arabidopsis wild type(Columbia)and its SA-altering mutants snc1 (suppressor of npr1-1, constitutive) with high SA level, nahG(tansgenic line)with low SA level and npr1-1(non-expressor of PR gene)with SA signaling blockage were used in this study. Results showed that a greater growth inhibition occurred in snc1,while a less inhibition was observed in nahG and npr1-1 plants. Although the anti-oxidative enzymes SOD and POD increased upon Cd exposure,they were insufficient to remove oxidative stress,especially in snc1 plants. The accumulations of soluble sugar and proline in the tested plants were positively related to their tolerance to Cd stress.

  2. Effect of exogenous application of salicylic acid on the drought stress responses ofGardenia jasminoides

    Institute of Scientific and Technical Information of China (English)

    XiaMei Yao; Jing Ma; Jing Ji; Chun Ou; WenQiang Gao

    2016-01-01

    The alleviative effects of exogenous salicylic acid (SA) on plants against drought stress were assessed inGardenia jasminoides seedlings treated with different concentrations of SA. Drought stress was simulated to a moderate level by 15% polyethylene glycol (PEG) 6000 treatment.Seedlings exposed to 15% PEG for 14 days exhibited a decrease in aboveground and underground dry mass, seedling height, root length, relative water content, photosynthetic pigment content, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), and water use efficiency. In PEG-stressed plants, the levels of proline, malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage rose significantly, whereas antioxidative activity, including superoxide, peroxidase, and catalase activities, declined in leaves. However, the presence of SA provided an effective method of mitigating PEG-caused physiological stresses on G. jasminoides seedlings, which depended on SA levels. PEG-treated plants exposed to SA at 0.5–1.0 mmol/L signif-icantly eased PEG-induced growth inhibition. Application of SA, especially at concentrations of 0.5–1.0 mmol/L, considerably improved photosynthetic pigments, photosynthesis, antioxidative activity, relative water content, and proline accumulation, and decreased MDA content, H2O2 content, and electrolyte leakage. By contrast, the positive effects were not evident, or even more severe, in PEG+SA4 treatment. Based on these physiological and biochemical data, a suitable concentration of SA, potential growth regulators, could be applied to enhance the drought tolerance of G. jasminoides.

  3. Molecular cloning and characterization of drought stress responsive abscisic acid-stress-ripening (Asr 1) gene from wild jujube, Ziziphus nummularia (Burm.f.) Wight & Arn.

    Science.gov (United States)

    Padaria, Jasdeep Chatrath; Yadav, Radha; Tarafdar, Avijit; Lone, Showkat Ahmad; Kumar, Kanika; Sivalingam, Palaiyur Nanjappan

    2016-08-01

    Drought is a calamitous abiotic stress hampering agricultural productivity all over the world and its severity is likely to increase further. Abscisic acid-stress-ripening proteins (ASR), are a group of small hydrophilic proteins which are induced by abscisic acid, stress and ripening in many plants. In the present study, ZnAsr 1 gene was fully characterized for the first time from Ziziphus nummularia, which is one of the most low water forbearing plant. Full length ZnAsr 1 gene was characterised and in silico analysis of ZnASR1 protein was done for predicting its phylogeny and physiochemical properties. To validate transcriptional pattern of ZnAsr 1 in response to drought stress, expression profiling in polyethylene glycol (PEG) induced Z. nummularia seedlings was studied by RT-qPCR analysis and heterologous expression of the recombinant ZnAsr1 in Escherichia coli. The nucleotide sequence analysis revealed that the complete open reading frame of ZnAsr 1 is 819 bp long encoding a protein of 273 amino acid residues, consisting of a histidine rich N terminus with an abscisic acid/water deficit stress domain and a nuclear targeting signal at the C terminus. In expression studies, ZnAsr 1 gene was found to be highly upregulated under drought stress and recombinant clones of E. coli cells expressing ZnASR1 protein showed better survival in PEG containing media. ZnAsr1 was proven to enhance drought stress tolerance in the recombinant E.coli cells expressing ZnASR1. The cloned ZnAsr1 after proper validation in a plant system, can be used to develop drought tolerant transgenic crops. PMID:27209581

  4. Acid resistance and response to pH-induced stress in two Lactobacillus plantarum strains with probiotic potential.

    Science.gov (United States)

    Šeme, H; Gjuračić, K; Kos, B; Fujs, Š; Štempelj, M; Petković, H; Šušković, J; Bogovič Matijašić, B; Kosec, G

    2015-01-01

    Two new Lactobacillus plantarum strains, KR6-DSM 28780 and M5 isolated from sour turnip and traditional dried fresh cheese, respectively, were evaluated for species identity, antibiotic susceptibility, resistance to gastrointestinal conditions and adaptive response to low pH. Resistance mechanisms involved in the adaptation to acid-induced stress in these two strains were investigated by quantitative PCR of the atpA, cfa1, mleS and hisD genes. In addition to absence of antibiotic resistance, the two L. plantarum strains showed excellent survival rates at pH values as low as 2.4. Adaptive response to low pH was clearly observed in both strains; strain KR6 was superior to M5, as demonstrated by its ability to survive during 3 h incubation at pH 2.0 upon adaptation to moderately acidic conditions. In contrast, acid adaptation did not significantly affect the survival rate during simulated passage through the gastrointestinal tract. In both strains, induction of histidine biosynthesis (hisD) was upregulated during the acid adaptation response. In addition, significant upregulation of the cfa1 gene, involved in modulation of membrane fatty acid composition, was observed during the adaptation phase in strain KR6 but not in strain M5. Cells adapted to moderately acidic conditions also showed a significantly increased viability after the lyophilisation procedure, a cross-protection phenomenon providing additional advantage in probiotic application.

  5. Growth, Gas Exchange, Abscisic Acid, and Calmodulin Response to Salt Stress in Three Poplars

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In the present study, we investigated the effects of increasing salinity on growth, gas exchange, abscisic acid(ABA), calmodulin (CAM), and the relevance to salt tolerance in seedlings of Populus euphratica Oliv. and cuttings of P. "pupularis 35-44" (P. popularis) and P. x euramericana cv. 1-214 (P. cv. Italica). The relative growth rates of shoot height (RGRH) for P. cv. Italica and P. popularis were severely reduced by increasing salt stress,whereas the growth reduction was relatively less in P. euphratica. Similarly, P. euphratica maintained higher net photosynthetic rates (Pn) and unit transpiration rates (TRN) than P. cv. Italica and P. popularis under conditions of higher salinity. Salinity caused a significant increase in leaf ABA and CaM in the three genotypes after the onset of stress, but NaCl-induced ABA and CaM accumulation was more pronounced in P. euphratica,suggesting that P. euphratica plants are more sensitive in sensing soil salinity than the other two poplars.Furthermore, P. euphratica maintained relatively higher ABA and CaM concentrations under conditions of high salinity. The higher capacity to synthesize stress signals, namely ABA and CaM, in P. euphratica and the contribution of this to the salt resistance of P. euphratica are discussed.

  6. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    Directory of Open Access Journals (Sweden)

    Lina Lindberg

    Full Text Available When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D and Zygosaccharomyces bailii (CBS7555 cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP2C 2.2× and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP2C 2.7×, when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to

  7. Response of peroxidase and catalase to acid rain stress during seed germination of rice, wheat, and rape

    Institute of Scientific and Technical Information of China (English)

    Lihong WANG; Xiaohua HUANG; Qing ZHOU

    2008-01-01

    Seed germination of plants with various acid-resistance display different responses to acid rain. To understand the reason why such differences occur, the effects of simulated acid rain (pH 2.5-5.0) on the activities of peroxidase (ROD) and catalase (CAT) during seed ger-mination of rice (O. sativa),-wheat (T. aestivum), and rape (B. chinensis var. oleifera) were investigated. Results indi-cated that the maximum change in activities of CAT and POD by acid rain treatment with different acidity and time in relation to the referent treatment without acid rain, was in the order: rice (28.8%, 31.7%)wheat (4.0)>rape (5.0). Moreover, the change in activity of POD was higher than that of CAT, which showed that POD was more sensitive to acid rain stress than CAT. The difference in the ability of POD and CAT in removing free radicals was one reason why the germina-tion indexes of these three species behaved differently.

  8. Salicylic acid antagonism of EDS1-driven cell death is important for immune and oxidative stress responses in Arabidopsis.

    Science.gov (United States)

    Straus, Marco R; Rietz, Steffen; Ver Loren van Themaat, Emiel; Bartsch, Michael; Parker, Jane E

    2010-05-01

    Reactive oxygen species (ROS) have emerged as signals in the responses of plants to stress. Arabidopsis Enhanced Disease Susceptibility1 (EDS1) regulates defense and cell death against biotrophic pathogens and controls cell death propagation in response to chloroplast-derived ROS. Arabidopsis Nudix hydrolase7 (nudt7) mutants are sensitized to photo-oxidative stress and display EDS1-dependent enhanced resistance, salicylic acid (SA) accumulation and initiation of cell death. Here we explored the relationship between EDS1, EDS1-regulated SA and ROS by examining gene expression profiles, photo-oxidative stress and resistance phenotypes of nudt7 mutants in combination with eds1 and the SA-biosynthetic mutant, sid2. We establish that EDS1 controls steps downstream of chloroplast-derived O(2)(*-) that lead to SA-assisted H(2)O(2) accumulation as part of a mechanism limiting cell death. A combination of EDS1-regulated SA-antagonized and SA-promoted processes is necessary for resistance to host-adapted pathogens and for a balanced response to photo-oxidative stress. In contrast to SA, the apoplastic ROS-producing enzyme NADPH oxidase RbohD promotes initiation of cell death during photo-oxidative stress. Thus, chloroplastic O(2)(*-) signals are processed by EDS1 to produce counter-balancing activities of SA and RbohD in the control of cell death. Our data strengthen the idea that EDS1 responds to the status of O(2)(*-) or O(2)(*-)-generated molecules to coordinate cell death and defense outputs. This activity may enable the plant to respond flexibly to different biotic and abiotic stresses in the environment.

  9. Acidic pH shock induces the expressions of a wide range of stress-response genes

    Directory of Open Access Journals (Sweden)

    Hong Soon-Kwang

    2008-12-01

    Full Text Available Abstract Background Environmental signals usually enhance secondary metabolite production in Streptomycetes by initiating complex signal transduction system. It is known that different sigma factors respond to different types of stresses, respectively in Streptomyces strains, which have a number of unique signal transduction mechanisms depending on the types of environmental shock. In this study, we wanted to know how a pH shock would affect the expression of various sigma factors and shock-related proteins in S. coelicolor A3(2. Results According to the results of transcriptional and proteomic analyses, the major number of sigma factor genes were upregulated by an acidic pH shock. Well-studied sigma factor genes of sigH (heat shock, sigR (oxidative stress, sigB (osmotic shock, and hrdD that play a major role in the secondary metabolism, were all strongly upregulated by the pH shock. A number of heat shock proteins including the DnaK family and chaperones such as GroEL2 were also observed to be upregulated by the pH shock, while their repressor of hspR was strongly downregulated. Oxidative stress-related proteins such as thioredoxin, catalase, superoxide dismutase, peroxidase, and osmotic shock-related protein such as vesicle synthases were also upregulated in overall. Conclusion From these observations, an acidic pH shock was considered to be one of the strongest stresses to influence a wide range of sigma factors and shock-related proteins including general stress response proteins. The upregulation of the sigma factors and shock proteins already found to be related to actinorhodin biosynthesis was considered to have contributed to enhanced actinorhodin productivity by mediating the pH shock signal to regulators or biosynthesis genes for actinorhodin production.

  10. Rapid Phosphatidic Acid Accumulation in Response to Low Temperature Stress in Arabidopsis is Generated through Diacylglycerol Kinase

    Directory of Open Access Journals (Sweden)

    Steven A. Arisz

    2013-01-01

    Full Text Available Phosphatidic acid (PtdOH is emerging as an important signalling lipid in abiotic stress responses in plants. The effect of cold stress was monitored using 32P-labelled seedlings and leaf discs of Arabidopsis thaliana. Low, non-freezing temperatures were found to trigger a very rapid 32P-PtdOH increase, peaking within 2 and 5 min, respectively. In principle, PtdOH can be generated through three different pathways, i.e. i via de novo phospholipid biosynthesis (through acylation of lyso-PtdOH, ii via phospholipase D hydrolysis of structural phospholipids or iii via phosphorylation of diacylglycerol (DAG by DAG kinase (DGK. Using a differential 32P-labelling protocol and a PLD-transphosphatidylation assay, evidence is provided that the rapid 32P-PtdOH response was primarily generated through DGK. A simultaneous decrease in the levels of 32P-PtdInsP, correlating in time, temperature dependency and magnitude with the increase in 32P-PtdOH, suggested that a PtdInsP-hydrolyzing PLC generated the DAG in this reaction. Testing T-DNA insertion lines available for the seven DGK genes, revealed no clear changes in 32P-PtdOH responses, suggesting functional redundancy. Similarly, known cold-stress mutants were analyzed to investigate whether the PtdOH response acted downstream of the respective gene products. The hos1, los1 and fry1 mutants were found to exhibit normal PtdOH responses. Slight changes were found for ice1, snow1, and the overexpression line Super-ICE1, however, this was not cold-specific and likely due to pleiotropic effects. A tentative model illustrating direct cold effects on phospholipid metabolism is presented.

  11. Long-Chain Bases, Phosphatidic Acid, MAPKs and Reactive Oxygen Species as Nodal Signal Transducers in stress responses in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Mariana eSaucedo-Garcia

    2015-02-01

    Full Text Available Due to their sessile condition, plants have developed sensitive, fast and successful ways to contend to environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases (MAPK and non-protein, smaller molecules, such as long chain bases, phosphatidic acid and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very different stimuli and evoke very different responses. These pleiotropic effects may be explained by the possibility that every one of these four mediators can be expressed from different sources, cellular location, temporality or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses.

  12. Transcriptome analysis of sorbic acid-stressed Bacillus subtilis reveals a nutrient limitation response and indicates plasma membrane remodeling

    NARCIS (Netherlands)

    A. ter Beek; B.J.F. Keijser; A. Boorsma; A. Zakrzewska; R. Orij; G.J. Smits; S. Brul

    2008-01-01

    The weak organic acid sorbic acid is a commonly used food preservative, as it inhibits the growth of bacteria, yeasts, and molds. We have used genome-wide transcriptional profiling of Bacillus subtilis cells during mild sorbic acid stress to reveal the growth-inhibitory activity of this preservative

  13. [Acid stress response of Salmonella and its relationship with virulence--a review].

    Science.gov (United States)

    Ren, Jie; Zhao, Mingwen; Yao, Yufeng

    2014-04-01

    As successful enteric bacteria, Salmonella spp. has to overcome the extreme acid condition in the stomach before invading into host intestinal epithelial cells. Salmonella spp. has evolved an adaptation to its replicative niche in the acidic environment. This review summarizes acid resistant characteristics of Salmonella, and introduces several mechanisms to acid resistance, including keeping internal pH homeostatic, synthesizing acid shock protein through several regulatory pathways and altering membrane character. The achievements will be significant for understanding and controlling Salmonella infections in the future.

  14. Polyphenolic responses of grapevine berries to light, temperature, oxidative stress, abscisic acid and jasmonic acid show specific developmental-dependent degrees of metabolic resilience to perturbation.

    Science.gov (United States)

    Degu, Asfaw; Ayenew, Biruk; Cramer, Grant R; Fait, Aaron

    2016-12-01

    Grape-berries are exposed to a plethora of abiotic and biotic stimuli during their development. The developmental and temporal regulation of grape berry polyphenol metabolism in response to various cues was investigated using LC-QTOF-MS based metabolite profiling. High light (2500μmolm(-2)s(-1)), high temperature (40°C), jasmonic acid (200μM), menadione (120μM) and abscisic acid (3.026mM) treatments were applied to detached berries. Greater magnitudes of metabolite fluctuations characterize the pre-veraison berries than the veraison stage in response to the treatments. Furthermore, a tighter co-response of metabolic processes was shown at veraison, likely supporting the resilience to change in response to stress. High temperature and ABA treatments led to greater magnitudes of change during the course of the experiment. The present study demonstrates the occurrence of differential patterns of metabolic responses specific to individual cues and berry developmental stage, which in the field are commonly associated and thus hardly discernable. PMID:27374601

  15. Population Heterogeneity of Lactobacillus plantarum WCFS1 Microcolonies in Response to and Recovery from Acid Stress

    NARCIS (Netherlands)

    Ingham, C.J.; Beerthuyzen, M.; Vlieg, J.E.T.V.H.

    2008-01-01

    Within an isogenic microbial population in a homogenous environment, individual bacteria can still exhibit differences in phenotype. Phenotypic heterogeneity can facilitate the survival of subpopulations under stress. As the gram-positive bacterium Lactobacillus plantarum grows, it acidifies the gro

  16. TolC is important for bacterial survival and oxidative stress response in Salmonella enterica serovar Choleraesuis in an acidic environment.

    Science.gov (United States)

    Lee, Jen-Jie; Wu, Ying-Chen; Kuo, Chih-Jung; Hsuan, Shih-Ling; Chen, Ter-Hsin

    2016-09-25

    The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions. Additionally, the mutant exhibited morphological changes during growth in an acidic medium, leading to the conflicting results of cell viability measured by spectrophotometry and colony-forming unit counting. Reverse-transcriptional-PCR analysis indicated that acid-related molecules, apparatus, or enzymes and oxidation-induced factors were significantly affected by the acidic environment in the null-tolC mutant. The elongated cellular morphology was restored by adding antioxidants to the culture medium. Furthermore, we found that increased cellular antioxidative activity provides an overlapping protection against acid killing, demonstrating the complexity of the bacterial acid stress response. Our findings reinforce the multifunctional characteristics of TolC in acid tolerance or oxidative stress resistance and support the correlative protection mechanism between oxygen- and acid-mediated stress responses in Salmonella enterica serovar Choleraesuis. PMID:27599929

  17. Response of Halomonas campisalis to saline stress: changes in growth kinetics, compatible solute production and membrane phospholipid fatty acid composition.

    Science.gov (United States)

    Aston, John E; Peyton, Brent M

    2007-09-01

    The haloalkaliphile Halomonas campisalis, isolated near Soap Lake, Washington, was grown under both aerobic and denitrifying conditions from 0 to 260 g L(-1) NaCl, with optimal growth occurring at 20 and 30 g L(-1) NaCl, respectively. Halomonas campisalis was observed to produce high concentrations of compatible solutes, most notably ectoine (up to 500 mM within the cytoplasm), but hydroxyectoine and glycine betaine were also detected. The types and amounts of compatible solutes produced depended on salinity and specific growth rate, as well as on the terminal electron acceptor available (O(2) or NO(3) (-)). A decrease in ectoine production was observed with NO(3) (-) as compared with O(2) as the terminal electron acceptor. In addition, changes in the phospholipid fatty acid composition were measured with changing salinity. An increase in trans fatty acids was observed in the absence of salinity, and may be a response to membrane instability. Cyclic fatty acids were also observed to increase, both in the absence of salinity, and at very high salinities, indicating cell stress at these conditions. PMID:17651393

  18. The Juvenile Phase of Maize Sees Upregulation of Stress-Response Genes and Is Extended by Exogenous Jasmonic Acid.

    Science.gov (United States)

    Beydler, Benjamin; Osadchuk, Krista; Cheng, Chi-Lien; Manak, J Robert; Irish, Erin E

    2016-08-01

    As maize (Zea mays) plants undergo vegetative phase change from juvenile to adult, they both exhibit heteroblasty, an abrupt change in patterns of leaf morphogenesis, and gain the ability to produce flowers. Both processes are under the control of microRNA156 (miR156), whose levels decline at the end of the juvenile phase. Gain of the ability to flower is conferred by the expression of miR156 targets that encode SQUAMOSA PROMOTER-BINDING transcription factors, which, when derepressed in the adult phase, induce the expression of MADS box transcription factors that promote maturation and flowering. How gene expression, including targets of those microRNAs, differs between the two phases remains an open question. Here, we compare transcript levels in primordia that will develop into juvenile or adult leaves to identify genes that define these two developmental states and may influence vegetative phase change. In comparisons among successive leaves at the same developmental stage, plastochron 6, three-fourths of approximately 1,100 differentially expressed genes were more highly expressed in primordia of juvenile leaves. This juvenile set was enriched in photosynthetic genes, particularly those associated with cyclic electron flow at photosystem I, and in genes involved in oxidative stress and retrograde redox signaling. Pathogen- and herbivory-responsive pathways including salicylic acid and jasmonic acid also were up-regulated in juvenile primordia; indeed, exogenous application of jasmonic acid delayed both the appearance of adult traits and the decline in the expression of miR156-encoding loci in maize seedlings. We hypothesize that the stresses associated with germination promote juvenile patterns of differentiation in maize. PMID:27307257

  19. Arabidopsis plastid AMOS1/EGY1 integrates abscisic acid signaling to regulate global gene expression response to ammonium stress

    KAUST Repository

    Li, Baohai

    2012-10-12

    Ammonium (NH4 +) is a ubiquitous intermediate of nitrogen metabolism but is notorious for its toxic effects on most organisms. Extensive studies of the underlying mechanisms of NH4 + toxicity have been reported in plants, but it is poorly understood how plants acclimate to high levels of NH4 +. Here, we identified an Arabidopsis (Arabidopsis thaliana) mutant, ammonium overly sensitive1 (amos1), that displays severe chlorosis under NH4 + stress. Map-based cloning shows amos1 to carry a mutation in EGY1 (for ethylene-dependent, gravitropism-deficient, and yellow-green-like protein1), which encodes a plastid metalloprotease. Transcriptomic analysis reveals that among the genes activated in response to NH4 +, 90% are regulated dependent on AMOS1/ EGY1. Furthermore, 63% of AMOS1/EGY1-dependent NH4 +-activated genes contain an ACGTG motif in their promoter region, a core motif of abscisic acid (ABA)-responsive elements. Consistent with this, our physiological, pharmacological, transcriptomic, and genetic data show that ABA signaling is a critical, but not the sole, downstream component of the AMOS1/EGY1-dependent pathway that regulates the expression of NH4 +-responsive genes and maintains chloroplast functionality under NH4 + stress. Importantly, abi4 mutants defective in ABA-dependent and retrograde signaling, but not ABA-deficient mutants, mimic leaf NH4 + hypersensitivity of amos1. In summary, our findings suggest that an NH4 +-responsive plastid retrograde pathway, which depends on AMOS1/EGY1 function and integrates with ABA signaling, is required for the regulation of expression of the presence of high NH4 + levels. © 2012 American Society of Plant Biologists. All Rights Reserved.

  20. Albumin-bound fatty acids induce mitochondrial oxidant stress and impair antioxidant responses in proximal tubular cells

    NARCIS (Netherlands)

    Ishola, D. A.; Post, J. A.; van Timmeren, M. M.; Bakker, S. J. L.; Goldschmeding, R.; Koomans, H. A.; Braam, B.; Joles, J. A.

    2006-01-01

    Albumin induces oxidative stress and cytokine production in proximal tubular cells (PTECs). Albumin-bound fatty acids (FAs) enhance tubulopathic effects of albumin in vivo. We proposed that FA aggravation of albumin-induced oxidative stress in PTECs might be involved. We hypothesized that mitochondr

  1. Monitoring Plant Hormones During Stress Responses

    OpenAIRE

    Engelberth, Marie J.; Engelberth, Jurgen

    2009-01-01

    Plant hormones and related signaling compounds play an important role in the regulation of plant responses to various environmental stimuli and stresses. Among the most severe stresses are insect herbivory, pathogen infection, and drought stress. For each of these stresses a specific set of hormones and/or combinations thereof are known to fine-tune the responses, thereby ensuring the plant's survival. The major hormones involved in the regulation of these responses are jasmonic acid (JA), sa...

  2. The Escherichia coli Acid Stress Response and Its Significance for Pathogenesis.

    Science.gov (United States)

    De Biase, Daniela; Lund, Peter A

    2015-01-01

    Escherichia coli has a remarkable ability to survive low pH and possesses a number of different genetic systems that enable it to do this. These may be expressed constitutively, typically in stationary phase, or induced by growth under a variety of conditions. The activities of these systems have been implicated in the ability of E. coli to pass the acidic barrier of the stomach and to become established in the gastrointestinal tract, something causing serious infections. However, much of the work characterizing these systems has been done on standard laboratory strains of E. coli and under conditions which do not closely resemble those found in the human gut. Here we review what is known about acid resistance in E. coli as a model laboratory organism and in the context of its lifestyle as an inhabitant-sometimes an unwelcome one-of the human gut.

  3. A consolidated analysis of the physiologic and molecular responses induced under acid stress in the legume-symbiont model-soil bacterium Sinorhizobium meliloti.

    Science.gov (United States)

    Draghi, W O; Del Papa, M F; Hellweg, C; Watt, S A; Watt, T F; Barsch, A; Lozano, M J; Lagares, A; Salas, M E; López, J L; Albicoro, F J; Nilsson, J F; Torres Tejerizo, G A; Luna, M F; Pistorio, M; Boiardi, J L; Pühler, A; Weidner, S; Niehaus, K; Lagares, A

    2016-01-01

    Abiotic stresses in general and extracellular acidity in particular disturb and limit nitrogen-fixing symbioses between rhizobia and their host legumes. Except for valuable molecular-biological studies on different rhizobia, no consolidated models have been formulated to describe the central physiologic changes that occur in acid-stressed bacteria. We present here an integrated analysis entailing the main cultural, metabolic, and molecular responses of the model bacterium Sinorhizobium meliloti growing under controlled acid stress in a chemostat. A stepwise extracellular acidification of the culture medium had indicated that S. meliloti stopped growing at ca. pH 6.0-6.1. Under such stress the rhizobia increased the O2 consumption per cell by more than 5-fold. This phenotype, together with an increase in the transcripts for several membrane cytochromes, entails a higher aerobic-respiration rate in the acid-stressed rhizobia. Multivariate analysis of global metabolome data served to unequivocally correlate specific-metabolite profiles with the extracellular pH, showing that at low pH the pentose-phosphate pathway exhibited increases in several transcripts, enzymes, and metabolites. Further analyses should be focused on the time course of the observed changes, its associated intracellular signaling, and on the comparison with the changes that operate during the sub lethal acid-adaptive response (ATR) in rhizobia. PMID:27404346

  4. Contrastive response of Brassica napus L. to exogenous salicylic acid, selenium and silicon supplementation under water stress

    OpenAIRE

    Habibi Ghader

    2015-01-01

    The present research was designed to determine the effects of exogenous salicylic acid (SA), selenium (Se) and silicon (Si) on the resistance of canola (Brassica napus L. cv Okapi) seedlings to salt stress. Foliar application of SA (0.1 mM) in canola plants under drought stress for 25 days exhibited a significantly positive effect on shoot dry mass and raised the levels of total chlorophyll as well as boosting the activity of superoxide dismutase (SOD) and ...

  5. Decoding genome-wide GadEWX-transcriptional regulatory networks reveals multifaceted cellular responses to acid stress in Escherichia coli

    DEFF Research Database (Denmark)

    Seo, Sang Woo; Kim, Donghyuk; O'Brien, Edward J.;

    2015-01-01

    . We demonstrate that GadEWX directly and coherently regulate several proton-generating/consuming enzymes with pairs of negative-feedback loops for pH homeostasis. In addition, GadEWX regulate genes with assorted functions, including molecular chaperones, acid resistance, stress response and other...

  6. Auxin response under osmotic stress.

    Science.gov (United States)

    Naser, Victoria; Shani, Eilon

    2016-08-01

    The phytohormone auxin (indole-3-acetic acid, IAA) is a small organic molecule that coordinates many of the key processes in plant development and adaptive growth. Plants regulate the auxin response pathways at multiple levels including biosynthesis, metabolism, transport and perception. One of the most striking aspects of plant plasticity is the modulation of development in response to changing growth environments. In this review, we explore recent findings correlating auxin response-dependent growth and development with osmotic stresses. Studies of water deficit, dehydration, salt, and other osmotic stresses point towards direct and indirect molecular perturbations in the auxin pathway. Osmotic stress stimuli modulate auxin responses by affecting auxin biosynthesis (YUC, TAA1), transport (PIN), perception (TIR/AFB, Aux/IAA), and inactivation/conjugation (GH3, miR167, IAR3) to coordinate growth and patterning. In turn, stress-modulated auxin gradients drive physiological and developmental mechanisms such as stomata aperture, aquaporin and lateral root positioning. We conclude by arguing that auxin-mediated growth inhibition under abiotic stress conditions is one of the developmental and physiological strategies to acclimate to the changing environment. PMID:27052306

  7. Auxin response under osmotic stress.

    Science.gov (United States)

    Naser, Victoria; Shani, Eilon

    2016-08-01

    The phytohormone auxin (indole-3-acetic acid, IAA) is a small organic molecule that coordinates many of the key processes in plant development and adaptive growth. Plants regulate the auxin response pathways at multiple levels including biosynthesis, metabolism, transport and perception. One of the most striking aspects of plant plasticity is the modulation of development in response to changing growth environments. In this review, we explore recent findings correlating auxin response-dependent growth and development with osmotic stresses. Studies of water deficit, dehydration, salt, and other osmotic stresses point towards direct and indirect molecular perturbations in the auxin pathway. Osmotic stress stimuli modulate auxin responses by affecting auxin biosynthesis (YUC, TAA1), transport (PIN), perception (TIR/AFB, Aux/IAA), and inactivation/conjugation (GH3, miR167, IAR3) to coordinate growth and patterning. In turn, stress-modulated auxin gradients drive physiological and developmental mechanisms such as stomata aperture, aquaporin and lateral root positioning. We conclude by arguing that auxin-mediated growth inhibition under abiotic stress conditions is one of the developmental and physiological strategies to acclimate to the changing environment.

  8. Physiological responses of Brassica napus to fulvic acid under water stress:Chlorophyll a fluorescence and antioxidant enzyme activity

    Institute of Scientific and Technical Information of China (English)

    Ramin Lotfi; Mohammad Pessarakli; Puriya Gharavi-Kouchebagh; Hossein Khoshvaghti

    2015-01-01

    The ameliorative effect of fulvic acid (0, 300, and 600 mg L−1) on photosystem II and antioxidant enzyme activity of the rapeseed (Brassica napus L.) plant under water stress (60, 100, and 140 mm evaporation from class A pan) was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid (FA) improved the maximum quantum efficiency of PSII (Fv/Fm) and performance index (PI) of plants under both well-watered and limited-water conditions. The time span from Fo to Fm and the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species (ROS) is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.

  9. Physiological responses of Brassica napus to fulvic acid under water stress: Chlorophyll a fluorescence and antioxidant enzyme activity

    Institute of Scientific and Technical Information of China (English)

    Ramin; Lotfi; Mohammad; Pessarakli; Puriya; Gharavi-Kouchebagh; Hossein; Khoshvaghti

    2015-01-01

    The ameliorative effect of fulvic acid(0, 300, and 600 mg L-1) on photosystem II and antioxidant enzyme activity of the rapeseed(Brassica napus L.) plant under water stress(60, 100, and 140 mm evaporation from class A pan) was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid(FA) improved the maximum quantum efficiency of PSII(Fv/Fm)and performance index(PI) of plants under both well-watered and limited-water conditions. The time span from Foto Fmand the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species(ROS) is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.

  10. Physiological responses of Brassica napus to fulvic acid under water stress: Chlorophyll a fluorescence and antioxidant enzyme activity

    Directory of Open Access Journals (Sweden)

    Ramin Lotfi

    2015-10-01

    Full Text Available The ameliorative effect of fulvic acid (0, 300, and 600 mg L− 1 on photosystem II and antioxidant enzyme activity of the rapeseed (Brassica napus L. plant under water stress (60, 100, and 140 mm evaporation from class A pan was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid (FA improved the maximum quantum efficiency of PSII (Fv/Fm and performance index (PI of plants under both well-watered and limited-water conditions. The time span from Fo to Fm and the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species (ROS is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.

  11. Effects of supplemental ascorbic acid on humeral immune response in broilers reared under heat-stress condition

    Directory of Open Access Journals (Sweden)

    Vahel J. A. Amedy,

    2011-07-01

    Full Text Available An experiment was conducted to evaluate the efficacy of supplemental ascorbic acid (Vitamin C on the haemagglutination inhibition (HI and enzyme linked immune sorbent assay (ELISA antibody titer of the commercial broiler chicks vaccinated against Newcastle disease (ND virus, reared under heat stress condition. A total of 420, one day-old broiler chicks were randomly divided into 4 groups and kept under elevated summer temperature and treated with four levels of added ascorbic acid i.e., 0 (control group, 200, 400, 600 mg/kg in diets for 28 days, from 21 to 49 days of experimental period. HI antibody titer and ELISA antibody titer against ND virus were significantly (P<0.05 higher at 600 mg/kg Vitamin C in the diet than the others treatments. Apparently, adding ascorbic acid at 600 mg/kg in the diet could improve humoral immunity in broilers reared under heat stress.

  12. Redox Signaling and CBF-Responsive Pathway Are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

    Science.gov (United States)

    Cheng, Fei; Lu, Junyang; Gao, Min; Shi, Kai; Kong, Qiusheng; Huang, Yuan; Bie, Zhilong

    2016-01-01

    Salicylic acid (SA) plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus). Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-α-aminooxy-β-phenylpropionic acid (AOPP) increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon. PMID:27777580

  13. The pepper late embryogenesis abundant protein CaLEA1 acts in regulating abscisic acid signaling, drought and salt stress response.

    Science.gov (United States)

    Lim, Chae Woo; Lim, Sohee; Baek, Woonhee; Lee, Sung Chul

    2015-08-01

    As sessile organisms, plants are constantly challenged by environmental stresses, including drought and high salinity. Among the various abiotic stresses, osmotic stress is one of the most important factors for growth and significantly reduces crop productivity in agriculture. Here, we report a function of the CaLEA1 protein in the defense responses of plants to osmotic stress. Our analyses showed that the CaLEA1 gene was strongly induced in pepper leaves exposed to drought and increased salinity. Furthermore, we determined that the CaLEA1 protein has a late embryogenesis abundant (LEA)_3 homolog domain highly conserved among other known group 5 LEA proteins and is localized in the processing body. We generated CaLEA1-silenced peppers and CaLEA1-overexpressing (OX) transgenic Arabidopsis plants to evaluate their responses to dehydration and high salinity. Virus-induced gene silencing of CaLEA1 in pepper plants conferred enhanced sensitivity to drought and salt stresses, which was accompanied by high levels of lipid peroxidation in dehydrated and NaCl-treated leaves. CaLEA1-OX plants exhibited enhanced sensitivity to abscisic acid (ABA) during seed germination and in the seedling stage; furthermore, these plants were more tolerant to drought and salt stress than the wild-type plants because of enhanced stomatal closure and increased expression of stress-responsive genes. Collectively, our data suggest that CaLEA1 positively regulates drought and salinity tolerance through ABA-mediated cell signaling. PMID:25302464

  14. Biocide tolerance, phenotypic and molecular response of lactic acid bacteria isolated from naturally-fermented Aloreña table to different physico-chemical stresses.

    Science.gov (United States)

    Casado Muñoz, María Del Carmen; Benomar, Nabil; Lavilla Lerma, Leyre; Knapp, Charles W; Gálvez, Antonio; Abriouel, Hikmate

    2016-12-01

    Lactic acid bacteria (LAB) isolated throughout the fermentation process of Aloreña table olives were found to be resistant at least to three antibiotics (Casado Muñoz et al., 2014); however, most were sensitive to the biocides tested in this study (with minimum inhibitory concentrations [MIC] below the epidemiological cut-off values). 2-15% of the isolates were found to be biocide resistant: Leuconostoc Pseudomesenteroides, which were resistant to hexachlorophene, and Lactobacillus pentosus to cetrimide and hexadecylpiridinium. We analyzed the effect of different physico-chemical stresses, including antimicrobials, on the phenotypic and genotypic responses of LAB, providing new insights on how they become resistant in a changing environment. Results indicated that similar phenotypic responses were obtained under three stress conditions: antimicrobials, chemicals and UV light. Susceptibility patterns to antibiotics changed: increasing MICs for ampicillin, chloramphenicol, ciprofloxacin, teicoplanin and tetracycline, and decreasing the MICs for clindamycin, erythromycin, streptomycin and trimethoprim in most strains. Statistically, cross resistance between different antibiotics was detected in all stress conditions. However, expression profiles of selected genes involved in stress/resistance response (rpsL, recA, uvrB and srtA) differed depending on the stress parameter, LAB species and strain, and the target gene. We conclude that, despite the uniform phenotypic response to stresses, the repertoire of induced and repressed genes differs. So, a search for a target to improve stress tolerance of LAB, especially those of importance as starter/protective cultures or probiotics, may depend on the individual screening of each strain, even though we could predict the antibiotic phenotypic response to all stresses. PMID:27554140

  15. Overexpression of the NDR1/HIN1-Like Gene NHL6 Modifies Seed Germination in Response to Abscisic Acid and Abiotic Stresses in Arabidopsis.

    Science.gov (United States)

    Bao, Yan; Song, Wei-Meng; Pan, Jing; Jiang, Chun-Mei; Srivastava, Renu; Li, Bei; Zhu, Lu-Ying; Su, Hong-Yan; Gao, Xiao-Shu; Liu, Hua; Yu, Xiang; Yang, Lei; Cheng, Xian-Hao; Zhang, Hong-Xia

    2016-01-01

    NHL (NDR1/HIN1-like) genes play crucial roles in pathogen induced plant responses to biotic stress. Here, we report the possible function of NHL6 in plant response to abscisic acid (ABA) and abiotic stress. NHL6 was highly expressed in non-germinated seeds, and its expression was strongly induced by ABA and multiple abiotic stress signals. Loss-of-function of NHL6 decreased sensitivity to ABA in the early developmental stages including seed germination and post-germination seedling growth of the nhl6 mutants. However, overexpression of NHL6 increased sensitivity to ABA, salt and osmotic stress of the transgenic plants. Further studies indicated that the increased sensitivity in the 35S::NHL6 overexpressing plants could be a result of both ABA hypersensitivity and increased endogenous ABA accumulation under the stress conditions. It was also seen that the ABA-responsive element binding factors AREB1, AREB2 and ABF3 could regulate NHL6 expression at transcriptional level. Our results indicate that NHL6 plays an important role in the abiotic stresses-induced ABA signaling and biosynthesis, particularly during seed germination and early seedling development in Arabidopsis.

  16. The upregulation of thiamine (vitamin B1 biosynthesis in Arabidopsis thaliana seedlings under salt and osmotic stress conditions is mediated by abscisic acid at the early stages of this stress response

    Directory of Open Access Journals (Sweden)

    Rapala-Kozik Maria

    2012-01-01

    Full Text Available Abstract Background Recent reports suggest that vitamin B1 (thiamine participates in the processes underlying plant adaptations to certain types of abiotic and biotic stress, mainly oxidative stress. Most of the genes coding for enzymes involved in thiamine biosynthesis in Arabidopsis thaliana have been identified. In our present study, we examined the expression of thiamine biosynthetic genes, of genes encoding thiamine diphosphate-dependent enzymes and the levels of thiamine compounds during the early (sensing and late (adaptation responses of Arabidopsis seedlings to oxidative, salinity and osmotic stress. The possible roles of plant hormones in the regulation of the thiamine contribution to stress responses were also explored. Results The expression of Arabidopsis genes involved in the thiamine diphosphate biosynthesis pathway, including that of THI1, THIC, TH1 and TPK, was analyzed for 48 h in seedlings subjected to NaCl or sorbitol treatment. These genes were found to be predominantly up-regulated in the early phase (2-6 h of the stress response. The changes in these gene transcript levels were further found to correlate with increases in thiamine and its diphosphate ester content in seedlings, as well as with the enhancement of gene expression for enzymes which require thiamine diphosphate as a cofactor, mainly α-ketoglutarate dehydrogenase, pyruvate dehydrogenase and transketolase. In the case of the phytohormones including the salicylic, jasmonic and abscisic acids which are known to be involved in plant stress responses, only abscisic acid was found to significantly influence the expression of thiamine biosynthetic genes, the thiamine diphosphate levels, as well as the expression of genes coding for main thiamine diphosphate-dependent enzymes. Using Arabidopsis mutant plants defective in abscisic acid production, we demonstrate that this phytohormone is important in the regulation of THI1 and THIC gene expression during salt stress

  17. Knockout of AtDjB1, a J-domain protein from Arabidopsis thaliana, alters plant responses to osmotic stress and abscisic acid.

    Science.gov (United States)

    Wang, Xingxing; Jia, Ning; Zhao, Chunlan; Fang, Yulu; Lv, Tingting; Zhou, Wei; Sun, Yongzhen; Li, Bing

    2014-10-01

    AtDjB1 is a member of the Arabidopsis thaliana J-protein family. AtDjB1 is targeted to the mitochondria and plays a crucial role in A. thaliana heat and oxidative stress resistance. Herein, the role of AtDjB1 in adapting to saline and drought stress was studied in A. thaliana. AtDjB1 expression was induced through salinity, dehydration and abscisic acid (ABA) in young seedlings. Reverse genetic analyses indicate that AtDjB1 is a negative regulator in plant osmotic stress tolerance. Further, AtDjB1 knockout mutant plants (atj1-1) exhibited greater ABA sensitivity compared with the wild-type (WT) plants and the mutant lines with a rescued AtDjB1 gene. AtDjB1 gene knockout also altered the expression of several ABA-responsive genes, which suggests that AtDjB1 is involved in osmotic stress tolerance through its effects on ABA signaling pathways. Moreover, atj1-1 plants exhibited higher glucose levels and greater glucose sensitivity in the post-germination development stage. Applying glucose promoted an ABA response in seedlings, and the promotion was more evident in atj1-1 than WT seedlings. Taken together, higher glucose levels in atj1-1 plants are likely responsible for the greater ABA sensitivity and increased osmotic stress tolerance. PMID:24521401

  18. The surgically induced stress response.

    Science.gov (United States)

    Finnerty, Celeste C; Mabvuure, Nigel Tapiwa; Ali, Arham; Kozar, Rosemary A; Herndon, David N

    2013-09-01

    The stress response to surgery, critical illness, trauma, and burns encompasses derangements of metabolic and physiological processes that induce perturbations in the inflammatory, acute phase, hormonal, and genomic responses. Hypermetabolism and hypercatabolism result, leading to muscle wasting, impaired immune function and wound healing, organ failure, and death. The surgery-induced stress response is largely similar to that triggered by traumatic injuries; the duration of the stress response, however, varies according to the severity of injury (surgical or traumatic). This spectrum of injuries and insults ranges from small lacerations to severe insults such as large poly-traumatic and burn injuries. Burn injuries provide an extreme model of trauma induced stress responses that can be used to study the long-term effects of a prolonged stress response. Although the stress response to acute trauma evolved to confer improved chances of survival following injury, in modern surgical practice the stress response can be detrimental. PMID:24009246

  19. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-09-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. PMID:27466284

  20. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-09-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.

  1. Changes in free amino acids and polyamine levels in Satsuma leaves in response to Asian citrus psyllid infestation and water stress.

    Science.gov (United States)

    Malik, Nasir S A; Perez, Jose L; Kunta, Madhurababu; Patt, Joseph M; Mangan, Robert L

    2014-12-01

    The effects of biotic and abiotic stresses on changes in amino acids and polyamine levels in Satsuma orange (Citrus unshiu; cultivar Owari) leaves were investigated. Asian citrus psyllids Diaphorina citri (Kuwayama) (ACP) infestation was used to induce biotic stress while a water deficit was imposed to induce abiotic stress. Potted trees were infested by placing 50 psyllids on 3 citrus leaves enclosed in nylon mesh bags for 5 d. A parallel set of plants were kept water stressed by maintaining the soil at 20% water holding capacity for 5 d. Levels of total free amino acids were higher in water stressed and ACP infested leaves. Polyamine putrescine increased in infested leaves but not in water stressed leaves. Proline was the most abundant amino acid and its levels significantly increased by both biotic and abiotic stresses. Proline levels in infested leaves were significantly higher than the water stressed leaves. Histidine, methionine, asparagine, arginine, serine, and leucine levels also increased significantly in infested leaves, but in water stressed leaves only leucine, methionine, and threonine increased. Levels of amino acids, such as tyrosine, isoleucine, phenylalanine, glutamic acid, and alanine, declined in infested leaves. Under water stress asparagine, phenylalanine, serine, and histidine also declined compared to controls. This indicates that while proteolysis occurred under both stresses, metabolic conversion of amino acids was different under the two stresses. In ACP infested leaves some amino acids may be used as feeding material and/or converted into secondary metabolites for defense. PMID:24178691

  2. Fatty acid oxidation and its impact on response of spontaneously hypertensive rat hearts to an adrenergic stress: benefits of a medium-chain fatty acid.

    Science.gov (United States)

    Labarthe, François; Khairallah, Maya; Bouchard, Bertrand; Stanley, William C; Des Rosiers, Christine

    2005-03-01

    The spontaneously hypertensive rat (SHR) is a model of cardiomyopathy characterized by a restricted use of exogenous long-chain fatty acid (LCFA) for energy production. The aims of the present study were to document the functional and metabolic response of the SHR heart under conditions of increased energy demand and the effects of a medium-chain fatty acid (MCFA; octanoate) supplementation in this situation. Hearts were perfused ex vivo in a working mode with physiological concentrations of substrates and hormones and subjected to an adrenergic stimulation (epinephrine, 10 microM). (13)C-labeled substrates were used to assess substrate selection for energy production. Compared with control Wistar rat hearts, SHR hearts showed an impaired response to the adrenergic stimulation as reflected by 1) a smaller increase in contractility and developed pressure, 2) a faster decline in the aortic flow, and 3) greater cardiac tissue damage (lactate dehydrogenase release: 1,577 +/- 118 vs. 825 +/- 44 mU/min, P citric acid cycle flux (16 +/- 1 vs. 44 +/- 4%, P acid contribution to energy metabolism (23.7 +/- 1.3 vs. 15.8 +/- 0.8%, P acid oxidation to energy production by MCFA supplementation.

  3. The Surgically Induced Stress Response

    OpenAIRE

    Finnerty, Celeste C.; Mabvuure, Nigel Tapiwa; Ali, Arham; Kozar, Rosemary A.; Herndon, David N

    2013-01-01

    The stress response to surgery, critical illness, trauma, and burns encompasses derangements of metabolic and physiological processes which induce perturbations in the inflammatory, acute phase, hormonal, and genomic responses. Hypermetabolism and hypercatabolism result, leading to muscle wasting, impaired immune function and wound healing, organ failure, and death. The surgery-induced stress response is largely similar to that triggered by traumatic injuries; the duration of the stress respo...

  4. Preventive effects of omega-3 and omega-6 Fatty acids on peroxide mediated oxidative stress responses in primary human trabecular meshwork cells.

    Directory of Open Access Journals (Sweden)

    Theofilos Tourtas

    Full Text Available Pathologic processes in glaucoma include increased apoptosis, accumulation of extracellular material in the trabecular meshwork and optic nerve, condensations of the cytoskeleton and precocious cellular senescence. Oxidative stress was shown to generate these alterations in primary ocular cells. Fatty acids omega-3 and -6 are alleged to constitute a prophylaxis against these deleterious effects. Here, we tested actual preventive effects omega-3 and -6 against peroxide induced stress responses in primary human trabecular meshwork cells. Changes of mitochondrial activity, proliferation, heat shock proteins, extracellular matrix components, and inflammatory markers were evaluated. Alterations of the cytoskeleton were evaluated by phalloidin labeling. Here we report a repressive effect of omega-6 on metabolic activity and proliferation, which was not detected for omega-3. Both agents were able to prevent the anti-proliferative effect of H₂O₂, but only omega-3 prevented metabolic repression. Expression of heat shock protein 27 was unaltered by both fatty acids, whereas heat shock protein 90 was significantly induced by both. Omega-6 increased fibronectin and connective tissue growth factor synthesis, as well as the amount of secreted fibronectin. Omega-3, instead, induced plasminogen activator inhibitor 1 synthesis. H₂O₂ further increased fibronectin production in omega-6 supplemented cells, which was not the case in omega-3 treated cells. H₂O₂ stimulation of plasminogen activator inhibitor 1 and connective tissue growth factor was repressed by both fatty acids. Both fatty acids appeared to abolish H₂O₂ mediated stimulation of nuclear factor κB and IL-6, but not IL-1α and IL-8. H₂O₂ induced formation of cross-linked actin networks and stress fibers, which was reduced by preemptive application of omega-3. Omega-6, in contrast, had no protective effect on that, and even seemed to promote condensation. Based on the observed side

  5. Mutation of the NADH Oxidase Gene (nox) Reveals an Overlap of the Oxygen- and Acid-Mediated Stress Responses in Streptococcus mutans

    OpenAIRE

    Derr, Adam M.; Faustoferri, Roberta C.; Betzenhauser, Matthew J.; Gonzalez, Kaisha; Marquis, Robert E.; Quivey, Robert G.

    2012-01-01

    NADH oxidase (Nox) is a flavin-containing enzyme used by Streptococcus mutans to reduce dissolved oxygen encountered during growth in the oral cavity. In this study, we characterized the role of the NADH oxidase in the oxidative and acid stress responses of S. mutans. A nox-defective mutant strain of S. mutans and its parental strain, the genomic type strain UA159, were exposed to various oxygen concentrations at pH values of 5 and 7 to better understand the adaptive mechanisms used by the or...

  6. The Surgically Induced Stress Response

    Science.gov (United States)

    Finnerty, Celeste C.; Mabvuure, Nigel Tapiwa; Ali, Arham; Kozar, Rosemary A.; Herndon, David N.

    2013-01-01

    The stress response to surgery, critical illness, trauma, and burns encompasses derangements of metabolic and physiological processes which induce perturbations in the inflammatory, acute phase, hormonal, and genomic responses. Hypermetabolism and hypercatabolism result, leading to muscle wasting, impaired immune function and wound healing, organ failure, and death. The surgery-induced stress response is largely similar to that triggered by traumatic injuries; the duration of the stress response, however, varies according to the severity of injury (surgical or traumatic). This spectrum of injuries and insults ranges from small lacerations to severe insults such as large poly-traumatic and burn injuries. Although the stress response to acute trauma evolved to improve chances of survival following injury, in modern surgical practice the stress response can be detrimental. PMID:24009246

  7. Nordihydroguaiaretic Acid from Creosote Bush (Larrea tridentata Mitigates 12-O-Tetradecanoylphorbol-13-Acetate-Induced Inflammatory and Oxidative Stress Responses of Tumor Promotion Cascade in Mouse Skin

    Directory of Open Access Journals (Sweden)

    Shakilur Rahman

    2011-01-01

    Full Text Available Nordihydroguaiaretic acid (NDGA is a phenolic antioxidant found in the leaves and twigs of the evergreen desert shrub, Larrea tridentata (Sesse and Moc. ex DC Coville (creosote bush. It has a long history of traditional medicinal use by the Native Americans and Mexicans. The modulatory effects of topically applied NDGA was studied on acute inflammatory and oxidative stress responses in mouse skin induced by stage I tumor promoting agent, 12-O-tetradecanoylphorbol-13-acetate (TPA. Double TPA treatment adversely altered many of the marker responses of stage I skin tumor promotion cascade. Pretreatment of NDGA in TPA-treated mice mitigated cutaneous lipid peroxidation and inhibited production of hydrogen peroxide. NDGA treatment also restored reduced glutathione level and activities of antioxidant enzymes. Elevated activities of myeloperoxidase, xanthine oxidase and skin edema formation in TPA-treated mice were also lowered by NDGA indicating a restrained inflammatory response. Furthermore, results of histological study demonstrated inhibitory effect of NDGA on cellular inflammatory responses. This study provides a direct evidence of antioxidative and anti-inflammatory properties of NDGA against TPA-induced cutaneous inflammation and oxidative stress corroborating its chemopreventive potential against skin cancer.

  8. Responses of antioxidant enzyme and photosynthesis in rape seedling to the combined stresses of acid rain and ultraviolet-B radiation

    Institute of Scientific and Technical Information of China (English)

    LIANG Chan-juan; HUANG Xiao-hua; TAO Wen-yi; ZHOU Qing

    2005-01-01

    Effects of the simulated acid rain(AR) and ultraviolet-B(UV-B, 280-320 nm) radiation with a single or two ways simultaneously (AR + UV-B) on the antioxidant enzyme and photosynthesis of the rape seedlings were investigated by the hydroponic culture. The results of static experiment indicated that the tolerance of rape seedling to single stress(AR or UV-B) is stronger than that to dual stresses(AR +UV-B). Furthermore, the dual stresses had additive effect on catalase activity, and a synergistic effect on MDA content, net photosynthesis rate, water use efficiency as well as intercellular CO2 concentration. Meanwhile, it has an independent effect on chlorophyll content, stomatal conductance, and transpiration rate as well as membrane permeability. During 64 h restoration course, the dynamic change in the curves of physiological and biochemical indices were not identical, and none of them show a simple linear variation.According to the static and dynamic experiments, it was found that a responsive sequence of catalase activity, membrane permeability,M DA content and photosynthetic characteristics to the above-mentioned stresses was as follows: AR + UV-B > UV-B > AR.

  9. A STRESS-RESPONSIVE NAC1-regulated protein phosphatase gene rice protein phosphatase18 modulates drought and oxidative stress tolerance through abscisic acid-independent reactive oxygen species scavenging in rice.

    Science.gov (United States)

    You, Jun; Zong, Wei; Hu, Honghong; Li, Xianghua; Xiao, Jinghua; Xiong, Lizhong

    2014-12-01

    Plants respond to abiotic stresses through a complexity of signaling pathways, and the dephosphorylation mediated by protein phosphatase (PP) is an important event in this process. We identified a rice (Oryza sativa) PP2C gene, OsPP18, as a STRESS-RESPONSIVE NAC1 (SNAC1)-regulated downstream gene. The ospp18 mutant was more sensitive than wild-type plants to drought stress at both the seedling and panicle development stages. Rice plants with OsPP18 suppressed through artificial microRNA were also hypersensitive to drought stress. Microarray analysis of the mutant revealed that genes encoding reactive oxygen species (ROS) scavenging enzymes were down-regulated in the ospp18 mutant, and the mutant exhibited reduced activities of ROS scavenging enzymes and increased sensitivity to oxidative stresses. Overexpression of OsPP18 in rice led to enhanced osmotic and oxidative stress tolerance. The expression of OsPP18 was induced by drought stress but not induced by abscisic acid (ABA). Although OsPP18 is a typical PP2C with enzymatic activity, it did not interact with SNF1-RELATED PROTEIN KINASE2 protein kinases, which function in ABA signaling. Meanwhile, the expression of ABA-responsive genes was not affected in the ospp18 mutant, and the ABA sensitivities of the ospp18 mutant and OsPP18-overexpressing plants were also not altered. Together, these findings suggest that OsPP18 is a unique PP2C gene that is regulated by SNAC1 and confers drought and oxidative stress tolerance by regulating ROS homeostasis through ABA-independent pathways.

  10. Effect of Poly(γ-glutamic acid) on the Physiological Responses and Calcium Signaling of Rape Seedlings (Brassica napus L.) under Cold Stress.

    Science.gov (United States)

    Lei, Peng; Xu, Zongqi; Ding, Yan; Tang, Bao; Zhang, Yunxia; Li, Huashan; Feng, Xiaohai; Xu, Hong

    2015-12-01

    Cold stress adversely affects plant growth and development. Poly(γ-glutamic acid) (γ-PGA) is a potential plant growth regulator that may be an effective cryoprotectant that prevents crops from damage during cold weather. In this study, the effects of γ-PGA on the physiological responses of rape seedlings subject to cold stress were investigated using hydroponic experiments. We determined that the malondialdehyde content was decreased by 33.4% and the proline content was increased by 62.5% by γ-PGA after 144 h under cold stress. Antioxidant enzymes activities were also evidently enhanced after treatment with γ-PGA. These responses counteracted increases in the fresh weight and chlorophyll content of rape seedlings, which increased by 24.5 and 50.9%, respectively, after 144 h, which meant that growth inhibition caused by cold was mitigated by γ-PGA. Our results also showed that γ-PGA also regulated Ca(2+) concentrations in the cytoplasm and calcium-dependent protein kinases, which are associated with cold resistance. In conclusion, we suggest that the Ca(2+)/CPKs signal pathway is involved in the γ-PGA-mediated enhancement of cold resistance in rape seedlings. PMID:26585291

  11. Four Arabidopsis AREB/ABF transcription factors function predominantly in gene expression downstream of SnRK2 kinases in abscisic acid signalling in response to osmotic stress.

    Science.gov (United States)

    Yoshida, Takuya; Fujita, Yasunari; Maruyama, Kyonoshin; Mogami, Junro; Todaka, Daisuke; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-01-01

    Under osmotic stress conditions such as drought and high salinity, the plant hormone abscisic acid (ABA) plays important roles in stress-responsive gene expression mainly through three bZIP transcription factors, AREB1/ABF2, AREB2/ABF4 and ABF3, which are activated by SNF1-related kinase 2s (SnRK2s) such as SRK2D/SnRK2.2, SRK2E/SnRK2.6 and SRK2I/SnRK2.3 (SRK2D/E/I). However, since the three AREB/ABFs are crucial, but not exclusive, for the SnRK2-mediated gene expression, transcriptional pathways governed by SRK2D/E/I are not fully understood. Here, we show that a bZIP transcription factor, ABF1, is a functional homolog of AREB1, AREB2 and ABF3 in ABA-dependent gene expression in Arabidopsis. Despite lower expression levels of ABF1 than those of the three AREB/ABFs, the areb1 areb2 abf3 abf1 mutant plants displayed increased sensitivity to drought and decreased sensitivity to ABA in primary root growth compared with the areb1 areb2 abf3 mutant. Genome-wide transcriptome analyses revealed that expression of downstream genes of SRK2D/E/I, which include many genes functioning in osmotic stress responses and tolerance such as transcription factors and LEA proteins, was mostly impaired in the quadruple mutant. Thus, these results indicate that the four AREB/ABFs are the predominant transcription factors downstream of SRK2D/E/I in ABA signalling in response to osmotic stress during vegetative growth.

  12. Neuronal responses to physiological stress

    DEFF Research Database (Denmark)

    Kagias, Konstantinos; Nehammer, Camilla; Pocock, Roger David John

    2012-01-01

    damage during aging that results in decline and eventual death. Studies have shown that the nervous system plays a pivotal role in responding to stress. Neurons not only receive and process information from the environment but also actively respond to various stresses to promote survival. These responses...... include changes in the expression of molecules such as transcription factors and microRNAs that regulate stress resistance and adaptation. Moreover, both intrinsic and extrinsic stresses have a tremendous impact on neuronal development and maintenance with implications in many diseases. Here, we review...... the responses of neurons to various physiological stressors at the molecular and cellular level....

  13. Characterization of VuMATE1 expression in response to iron nutrition and aluminum stress reveals adaptation of rice bean (Vigna umbellata to acid soils through cis regulation

    Directory of Open Access Journals (Sweden)

    Meiya eLiu

    2016-04-01

    Full Text Available Rice bean (Vigna umbellata VuMATE1 appears to be constitutively expressed at vascular system but root apex, and Al stress extends its expression to root apex. Whether VuMATE1 participates in both Al tolerance and Fe nutrition, and how VuMATE1 expression is regulated is of great interest. In this study, the role of VuMATE1 in Fe nutrition was characterized through in planta complementation assays. The transcriptional regulation of VuMATE1 was investigated through promoter analysis and promoter-GUS reporter assays. The results showed that the expression of VuMATE1 was regulated by Al stress but not Fe status. Complementation of frd3-1 with VuMATE1 under VuMATE1 promoter could not restore phenotype, but restored with 35SCaMV promoter. Immunostaining of VuMATE1 revealed abnormal localization of VuMATE1 in vasculature. In planta GUS reporter assay identified Al-responsive cis-acting elements resided between -1228 and -574 bp. Promoter analysis revealed several cis-acting elements, but transcription is not simply regulated by one of these elements. We demonstrated that cis regulation of VuMATE1 expression is involved in Al tolerance mechanism, while not involved in Fe nutrition. These results reveal the evolution of VuMATE1 expression for better adaptation of rice bean to acidic soils where Al stress imposed but Fe deficiency pressure released.

  14. Neuronal responses to physiological stress

    Directory of Open Access Journals (Sweden)

    Konstantinos eKagias

    2012-10-01

    Full Text Available Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. Physiological stress can be divided into three different aspects: environmental stress, intrinsic developmental stress and aging. Throughout life all living organisms are challenged by changes in the environment. Fluctuations in oxygen levels, temperature and redox state for example, trigger molecular events that enable an organism to adapt, survive and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner chemistry during normal development. For example, conditions such as intrinsic hypoxia and oxidative stress, which result from an increase in tissue mass, have to be confronted by developing embryos in order to complete their development. Finally, organisms face the challenge of stochastic accumulation of molecular damage during aging that results in decline and eventual death. Studies have shown that the nervous system plays a pivotal role in responding to stress. Neurons not only receive and process information from the environment but also actively respond to various stresses to promote survival. These responses include changes in the expression of molecules such as transcription factors and microRNAs that regulate stress resistance and adaptation. Moreover, both intrinsic and extrinsic stresses have a tremendous impact on neuronal development and maintenance with implications in many diseases. Here, we review the responses of neurons to various physiological stressors at the molecular and cellular level.

  15. Interleukin-6 deficiency reduces the brain inflammatory response and increases oxidative stress and neurodegeneration after kainic acid-induced seizures

    DEFF Research Database (Denmark)

    Penkowa, M; Molinero, A; Carrasco, J;

    2001-01-01

    The role of interleukin-6 in hippocampal tissue damage after injection with kainic acid, a rigid glutamate analogue inducing epileptic seizures, has been studied by means of interleukin-6 null mice. At 35mg/kg, kainic acid induced convulsions in both control (75%) and interleukin-6 null (100%) mi...

  16. An overview of stress response proteomes in Listeria monocytogenes

    OpenAIRE

    Soni, K A; Nannapaneni, R; Tasara, T

    2011-01-01

    Listeria monocytogenes adapts to diverse stress conditions including cold, osmotic, heat, acid, and alkali stresses encountered during food processing and preservation which is a serious food safety threat. In this review, we have presented the major findings on this bacterium’s stress response proteomes to date along with the different approaches used for its proteomic analysis. The key proteome findings on cold, heat shock, salt, acid, alkaline and HHP stresses illustrate that the cellular ...

  17. Neuronal responses to physiological stress.

    Science.gov (United States)

    Kagias, Konstantinos; Nehammer, Camilla; Pocock, Roger

    2012-01-01

    Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. It can be divided into three different aspects: environmental stress, intrinsic developmental stress, and aging. Throughout life all living organisms are challenged by changes in the environment. Fluctuations in oxygen levels, temperature, and redox state for example, trigger molecular events that enable an organism to adapt, survive, and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner chemistry during normal development. For example, conditions such as intrinsic hypoxia and oxidative stress, due to an increase in tissue mass, have to be confronted by developing embryos in order to complete their development. Finally, organisms face the challenge of stochastic accumulation of molecular damage during aging that results in decline and eventual death. Studies have shown that the nervous system plays a pivotal role in responding to stress. Neurons not only receive and process information from the environment but also actively respond to various stresses to promote survival. These responses include changes in the expression of molecules such as transcription factors and microRNAs that regulate stress resistance and adaptation. Moreover, both intrinsic and extrinsic stresses have a tremendous impact on neuronal development and maintenance with implications in many diseases. Here, we review the responses of neurons to various physiological stressors at the molecular and cellular level. PMID:23112806

  18. Response of Fe-S cluster assembly machinery of Escherichia coli to mechanical stress in a model of amino-acid crystal fermentation.

    Science.gov (United States)

    Okutani, Satoshi; Iwai, Takayoshi; Iwatani, Shintaro; Matsuno, Kiyoshi; Takahashi, Yasuhiro; Hase, Toshiharu

    2015-09-01

    During amino-acid crystal fermentation, mechanical stress on bacterial cells caused by crystal collision often impacts negatively on bacterial growth and amino-acid production. When Escherichia coli cells were cultivated under mechanical stress of polyvinyl chloride particles as a model of the crystal fermentation, activities of iron-sulfur (Fe-S) cluster-containing enzymes were apparently decreased. Based on an assumption that function of Fe-S cluster assembly machinery would be elevated to recover the enzyme activities in such stressed cells, we analyzed levels of various components of Fe-S cluster assembly machinery by western blotting. It was found that the expression of HscA, a chaperon component of the machinery, was up-regulated and that shorter forms of HscA with the N-terminal region truncated were accumulated, suggesting an important role of HscA against the mechanical stress. An overexpression of HscA gene in E. coli cells gave a positive effect on rescue of the stress-induced decrease of the activity of Fe-S cluster-containing enzyme. These results may provide a new strategy to alleviate the mechanical stress during the amino-acid crystal fermentation.

  19. Acid Tolerance Response of Anaerobic Sludge with Butyric Acid Stress during the Enhanced Biohydrogen Process%生物产氢过程中厌氧污泥耐酸响应的生物化学机制

    Institute of Scientific and Technical Information of China (English)

    孟影; 张光生; 王爱杰; 严群

    2012-01-01

    During the anaerobic digestion of biomass,large amounts of organic acids were produced. This results in an inhibitory effect on anaerobic microbiology,which in turn inhibits large-scale production of hydrogen. In this study, butyric acid was use as stress on the sludge, and it was found that the production rates of butyric acid, acetic acid and hydrogenwas reached at 400 mmol/mol, 1100 mmol/mol, 3690 mL/mol, respectively, which was higher 110%, 54% and 65% than that of the corresponding values in the control group. Moreover, glutamate acid decarboxylase (GAD) activity, dehydrogenase activity and the content of DNA was in-creased to 11. 6 ,μm/(g · TS · h), 6982. 12 μg TF/(g · TS · h) 14. 72 ng/mL, with an increment of 48%, 50%, 10.7%, respectively, and the content of extracellular polymeric substances (EPS) have improved significantly, loose bound protein, loose bound polysaccharide, tight bound protein and tight bound polysaccharide content were 147%, 34. 8%, 35%, 21. 6% higher than that of the control. The results demonstrate that the appropriate concentration of butyric acid stress on sludge can excite acid tolerance response (Acid tolerance response, ATR) and to improve acid tolerance of sludge, and improve the efficiency of anaerobic hydrogen production.%生物质厌氧发酵产氢过程中积累的大量酸性物质,会对厌氧微生物产生抑制作用,进而制约氢气的持续产生.作者采用不同浓度丁酸对污泥进行胁迫,结果表明:当丁酸胁迫质量浓度为6 g/L时,污泥厌氧发酵过程中丁酸、乙酸以及氢气产量最高,分别达到1 071 mmol/mol,462mmol/mol和3 690 mL/mol,比对照组分别提高了110%,54%和65%;此外,产氢过程中谷氨酸脱羧酶(glutamic acid decarboxylase,GAD)、脱氢酶以及DNA总量活性最高达到11.6μmol/(g·TS·h),6 982.12 μg TF/(g·TS·h),14.72 ng/mL,相对于对照组分别提高了48%,50%,10.7%;同时,经过酸胁迫后,

  20. Plant Responses to Nanoparticle Stress

    Directory of Open Access Journals (Sweden)

    Zahed Hossain

    2015-11-01

    Full Text Available With the rapid advancement in nanotechnology, release of nanoscale materials into the environment is inevitable. Such contamination may negatively influence the functioning of the ecosystems. Many manufactured nanoparticles (NPs contain heavy metals, which can cause soil and water contamination. Proteomic techniques have contributed substantially in understanding the molecular mechanisms of plant responses against various stresses by providing a link between gene expression and cell metabolism. As the coding regions of genome are responsible for plant adaptation to adverse conditions, protein signatures provide insights into the phytotoxicity of NPs at proteome level. This review summarizes the recent contributions of plant proteomic research to elaborate the complex molecular pathways of plant response to NPs stress.

  1. Cortical and subcortical gamma amino acid butyric acid deficits in anxiety and stress disorders: Clinical implications

    OpenAIRE

    Goddard, Andrew W

    2016-01-01

    Anxiety and stress disorders are a major public health issue. However, their pathophysiology is still unclear. The gamma amino acid butyric acid (GABA) neurochemical system has been strongly implicated in their pathogenesis and treatment by numerous preclinical and clinical studies, the most recent of which have been highlighted and critical review in this paper. Changes in cortical GABA appear related to normal personality styles and responses to stress. While there is accumulating animal an...

  2. How plants handle multiple stresses: hormonal interactions underlying responses to abiotic stress and insect herbivory.

    Science.gov (United States)

    Nguyen, Duy; Rieu, Ivo; Mariani, Celestina; van Dam, Nicole M

    2016-08-01

    Adaptive plant responses to specific abiotic stresses or biotic agents are fine-tuned by a network of hormonal signaling cascades, including abscisic acid (ABA), ethylene, jasmonic acid (JA) and salicylic acid. Moreover, hormonal cross-talk modulates plant responses to abiotic stresses and defenses against insect herbivores when they occur simultaneously. How such interactions affect plant responses under multiple stresses, however, is less understood, even though this may frequently occur in natural environments. Here, we review our current knowledge on how hormonal signaling regulates abiotic stress responses and defenses against insects, and discuss the few recent studies that attempted to dissect hormonal interactions occurring under simultaneous abiotic stress and herbivory. Based on this we hypothesize that drought stress enhances insect resistance due to synergistic interactions between JA and ABA signaling. Responses to flooding or waterlogging involve ethylene signaling, which likely reduces plant resistance to chewing herbivores due to its negative cross-talk with JA. However, the outcome of interactions between biotic and abiotic stress signaling is often plant and/or insect species-dependent and cannot simply be predicted based on general knowledge on the involvement of signaling pathways in single stress responses. More experimental data on non-model plant and insect species are needed to reveal general patterns and better understand the molecular mechanisms allowing plants to optimize their responses in complex environments. PMID:27095445

  3. [Response of reactive oxygen metabolism in melon chloroplasts to short-term salinity-alkalinity stress regulated by exogenous γ-aminobutyric acid].

    Science.gov (United States)

    Xiang, Li-xia; Hu, Li-pan; Hu, Xiao-hui; Pan, Xiong-bo; Ren, Wen-qi

    2015-12-01

    The regulatory effect of exogenous γ-aminobutyric acid (GABA) on metabolism of reactive oxygen species (ROS) in melon chloroplasts under short-term salinity-alkalinity stress were investigated in melon variety 'Jinhui No. 1', which was cultured with deep flow hydroponics. The result showed that under salinity-alkalinity stress, the photosynthetic pigment content, MDA content, superoxide anion (O₂·) production rate and hydrogen peroxide (H₂O₂) content in chloroplast increased significantly, the contents of antioxidants ascorbic acid (AsA) and glutathione (GSH) increased, and the activities of H⁺-ATPase and H⁺-PPiase were inhibited obviously. With exogenous GABA application, the accumulations of O₂·, MDA and H₂O₂ induced by salinity-alkalinity stress were inhibited. Exogenous GABA alleviated the increase of photosynthetic pigment content, improved the activity of SOD, enzymes of AsA-GSH cycle, total AsA and total GSH while decreased the AsA/DHA ratio and GSH/GSSH ratio. Foliar GABA could enhance the H⁺-ATPase and H⁺-PPiase activities. Our results suggested that the exogenous GABA could accelerate the ROS metabolism in chloroplast, promote the recycle of AsA-GSH, and maintain the permeability of cell membrane to improve the ability of melon chloroplast against salinity-alkalinity stress. PMID:27112014

  4. [Response of reactive oxygen metabolism in melon chloroplasts to short-term salinity-alkalinity stress regulated by exogenous γ-aminobutyric acid].

    Science.gov (United States)

    Xiang, Li-xia; Hu, Li-pan; Hu, Xiao-hui; Pan, Xiong-bo; Ren, Wen-qi

    2015-12-01

    The regulatory effect of exogenous γ-aminobutyric acid (GABA) on metabolism of reactive oxygen species (ROS) in melon chloroplasts under short-term salinity-alkalinity stress were investigated in melon variety 'Jinhui No. 1', which was cultured with deep flow hydroponics. The result showed that under salinity-alkalinity stress, the photosynthetic pigment content, MDA content, superoxide anion (O₂·) production rate and hydrogen peroxide (H₂O₂) content in chloroplast increased significantly, the contents of antioxidants ascorbic acid (AsA) and glutathione (GSH) increased, and the activities of H⁺-ATPase and H⁺-PPiase were inhibited obviously. With exogenous GABA application, the accumulations of O₂·, MDA and H₂O₂ induced by salinity-alkalinity stress were inhibited. Exogenous GABA alleviated the increase of photosynthetic pigment content, improved the activity of SOD, enzymes of AsA-GSH cycle, total AsA and total GSH while decreased the AsA/DHA ratio and GSH/GSSH ratio. Foliar GABA could enhance the H⁺-ATPase and H⁺-PPiase activities. Our results suggested that the exogenous GABA could accelerate the ROS metabolism in chloroplast, promote the recycle of AsA-GSH, and maintain the permeability of cell membrane to improve the ability of melon chloroplast against salinity-alkalinity stress.

  5. Hyperglycemic stress response in Crustacea

    Directory of Open Access Journals (Sweden)

    S Lorenzon

    2005-09-01

    Full Text Available Blood glucose level in crustaceans is controlled by the crustacean Hyperglycemic Hormone (cHH,released from the eyestalk neuroendocrine centres both under physiological and environmental stressconditions. Hyperglycemia is a typical response of many aquatic animals to pollutants and stress and,in crustaceans, increased circulating cHH and hyperglycemia are reported to result from exposure toseveral environmental stressors. Biogenic amines and enkephalin have been found to mediate therelease of several neurohormones from crustacean neuroendocrine tissue and a model of thecontrolling network is proposed.

  6. Combinatorial stress responses: direct coupling of two major stress responses in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Daniel R. Brown

    2014-09-01

    Full Text Available Nitrogen is an essential element for all life, and this is no different for the bacterial cell. Numerous cellular macromolecules contain nitrogen, including proteins, nucleic acids and cell wall components. In Escherichia coli and related bacteria, the nitrogen stress (Ntr response allows cells to rapidly sense and adapt to nitrogen limitation by scavenging for alternative nitrogen sources through the transcriptional activation of transport systems and catabolic and biosynthetic operons by the global transcriptional regulator NtrC. Nitrogen-starved bacterial cells also synthesize the (pppGpp effector molecules of a second global bacterial stress response - the stringent response. Recently, we showed that the transcription of relA, the gene which encodes the major (pppGpp synthetase in E. coli, is activated by NtrC during nitrogen starvation. Our results revealed that in E. coli and related bacteria, NtrC functions in combinatorial stress and serves to couple two major stress responses, the Ntr response and stringent response.

  7. Ascorbic Acid and/or 24-Epibrassinolide Trigger Physiological and Biochemical Responses for the Salt Stress Mitigation in Potato (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Chandrama Prakash Upadhyaya

    2015-12-01

    Full Text Available In the present study, we examined the role of ascorbic acid (AsA, vitamin C and/or 24-epibrassinolide (EBL, an active BR in mitigation of salt-induced stress in potato (Solanum tuberousum L. The 10-d-old plants were exposed to 150 mM NaCl and they were subsequently treated by ASA and/or EBL. The salt stress reduced significantly the plant growth, tuber yield, total chlorophyll and increased proline content and electrolyte leakage in the leaves. Toxic effects induced by salt stress were completely overcome by the combined exogenous application of AsA and EBL. The AsA and/or EBL treatments improved the growth parameters of the salt treated plants, such as shoot length, tuber number and size, fresh and dry mass and other physiological parameters. Our data also indicated that applications of AsA and EBL up-regulated the stress regulating plant hormone such as IAA, IBA and activities of the antioxidant enzymes, such as catalase (CAT, peroxidase (POX, superoxide dismutase (SOD, ascorbate peroxidase (APX and under salt stress.

  8. Transcriptional profiling of the PDR gene family in rice roots in response to plant growth regulators, redox perturbations and weak organic acid stresses.

    Science.gov (United States)

    Moons, Ann

    2008-12-01

    The role of plant pleiotropic drug resistance (PDR) type ATP-binding cassette (ABC) transporters remains poorly understood. We characterized the expression of the rice pleiotropic drug resistance (PDR) gene family in roots, where PDR transporters are believed to have major functions. A prototypical oligonucleotide array was developed containing 70-mers chosen in the gene-specific 3' untranslated regions of the rice PDR genes, other full-molecule rice ABC transporter genes and relevant marker genes. Jasmonates, which are involved in plant defense and secondary metabolism, proved major inducers of PDR gene expression. Over half of the PDR genes were JA-induced in roots of rice; OsPDR9 to the highest level. Salicylic acid, involved in plant pathogen defense, markedly induced the expression of OsPDR20. OsPDR20 was cDNA cloned and characterized. Abscisic acid, typically involved in water deficit responses, particularly induced OsPDR3 in roots and shoot and OsPDR6 in rice leaves. OsPDR9 and OsPDR20 were furthermore up-regulated in response to dithiothreitol- or glutathione-induced redox perturbations. Exogenous application of the weak organic acids lactic acid, malic acid, and citric acid differentially induced the expression of OsPDR3, OsPDR8, OsPDR9 and OsPDR20 in rice seedling roots. This transcriptional survey represents a guide for the further functional analysis of individual PDR transporters in roots of rice.

  9. Abscisic Acid and Abiotic Stress Tolerance in Crop Plants.

    Science.gov (United States)

    Sah, Saroj K; Reddy, Kambham R; Li, Jiaxu

    2016-01-01

    Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, abscisic acid (ABA) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression. PMID:27200044

  10. Effects of ionizing radiations on 1-aminocyclo-propane-1-carloxylic acid metabolism in climateric fruits. Analysis of stress response and implication in fruit ripening

    International Nuclear Information System (INIS)

    Ethylene is a plant hormone which regulates many aspects of ripening, senescence and stress response. The results show that irradiation can also be considered as a stress factor. Ethylene production enhancement which follows irradiation is the consequence of ACC synthase activation, and results from a de novo synthesis of the enzyme and in some cases from a very fast (15 mn) translation of already presents mRNAS. In cherry tomatoe fruits the onset of the ripening process occurs earlier. This modification is the consequence of two contradictory effects: - the short term activation of the ACC metabolism. - the ionization impact on genome and the consecutive impairing of transcriptional processes. These two aspects are dependent on the irradiation dose. They bring in cherry tomatoes a synchronization of the ripening process. The stress response towards ionization and CuC12 was also investigated on cell fruit suspensions. Results are dependent on the stress nature, material and physiological cell condition. They confirm the previous observed activation of ACC synthesis, which seems to be a general feature in non senescent systems

  11. Cytoplasmic pH Response to Acid Stress in Individual Cells of Escherichia coli and Bacillus subtilis Observed by Fluorescence Ratio Imaging Microscopy

    OpenAIRE

    Martinez, Keith A.; Ryan D Kitko; Mershon, J. Patrick; Adcox, Haley E.; Malek, Kotiba A.; Berkmen, Melanie B.; Slonczewski, Joan L.

    2012-01-01

    The ability of Escherichia coli and Bacillus subtilis to regulate their cytoplasmic pH is well studied in cell suspensions but is poorly understood in individual adherent cells and biofilms. We observed the cytoplasmic pH of individual cells using ratiometric pHluorin. A standard curve equating the fluorescence ratio with pH was obtained by perfusion at a range of external pH 5.0 to 9.0, with uncouplers that collapse the transmembrane pH difference. Adherent cells were acid stressed by switch...

  12. Effects of {sup 12}C{sup 6+} ion radiation and ferulic acid on the zebrafish (Danio rerio) embryonic oxidative stress response and gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Si, Jing [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Zhang, Hong, E-mail: zhangh@impcas.ac.cn [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Wang, Zhenhua; Wu, Zhenhua [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Lu, Jiang [Key Laboratory of Xinjiang Phytomedicine Resources, College of Pharmacy, Shihezi University, Shihezi 832002 (China); Di, Cuixia; Zhou, Xin [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Wang, Xiaowei [Key Laboratory of Xinjiang Phytomedicine Resources, College of Pharmacy, Shihezi University, Shihezi 832002 (China)

    2013-05-15

    Highlights: • Carbon ion radiation increased the oxidative stress in zebrafish embryos. • Carbon ion radiation induced transcriptional level effects. • The transcriptional level displayed more sensitivity to low dose radiation than the antioxidant enzyme activities. • FA induced radioprotective effects by the inhibition of oxidative stress. - Abstract: The effects of carbon ion irradiation and ferulic acid (FA) on the induction of oxidative stress and alteration of gene expression were studied in zebrafish (Danio rerio) embryos. Zebrafish embryos at 8 hpf were divided into seven groups: the control group; the 1 Gy, 3 Gy and 7 Gy irradiation groups; and three FA-pre-treated irradiation groups. In the irradiated groups, a significant increase in the teratogenesis of the zebrafish embryos and oxidative stress was accompanied by increased malondialdehyde (MDA) content, decreased glutathione (GSH) content and alterations in antioxidant enzyme activities (such as catalase [CAT] and superoxide dismutase [SOD]). Moreover, the mRNA levels for Cu/Zn–sod, Mn–sod, cat and gpx, the genes encoding these antioxidant proteins, were altered significantly. However, the mRNA expression patterns were not in accordance with those of the antioxidant enzymes and were more sensitive under low-dose irradiation. In addition, we detected the mRNA expression of ucp-2 and bcl-2, which are located at the mitochondrial inner membrane and related to reactive oxidative species (ROS) production. In the irradiated groups, the mRNA level of ucp-2 was significantly increased, whereas the mRNA level of bcl-2 was significantly decreased. Supplementation with FA, an antioxidant, was better able to reduce the irradiation-induced oxidative damage marked by changes in mortality, morphology, antioxidant enzyme activities and the MDA and GSH content, as well as in the mRNA expression levels. Overall, this study provided helpful information about the transcriptional effects of irradiation to better

  13. Sumo and the cellular stress response

    OpenAIRE

    Enserink, Jorrit M.

    2015-01-01

    The ubiquitin family member Sumo has important functions in many cellular processes including DNA repair, transcription and cell division. Numerous studies have shown that Sumo is essential for maintaining cell homeostasis when the cell encounters endogenous or environmental stress, such as osmotic stress, hypoxia, heat shock, genotoxic stress, and nutrient stress. Regulation of transcription is a key component of the Sumo stress response, and multiple mechanisms have been described by which ...

  14. Transgenerational response to stress in Arabidopsis thaliana

    OpenAIRE

    Boyko, Alex; Kovalchuk, Igor

    2010-01-01

    Plants exposed to stress pass the memory of exposure to stress to the progeny. Previously, we showed that the phenomenon of transgenerational memory of stress is of epigenetic nature and depends on the function of Dicer-like (DCL) 2 and DCL3 proteins. Here, we discuss a possible role of DNA methylation and function of small RNAs in establishing and maintaining transgenerational responses to stress. Our new data report that memory of stress is passed to the progeny predominantly through the fe...

  15. Phosphate-dependent root system architecture responses to salt stress

    KAUST Repository

    Kawa, Dorota

    2016-05-20

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced main root length and increased the number of lateral roots of Arabidopsis Col-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75mM) on all measured RSA components. At higher NaCl concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid (ABA) signaling compared to the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By Genome Wide Association Mapping (GWAS) 13 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses.

  16. Agreeableness, Extraversion, Stressor and Physiological Stress Response

    OpenAIRE

    Xiaoyuan Chu; Zhentao Ma; Yuan Li; Jing Han

    2015-01-01

    Based on the theoretical analysis, with first-hand data collection and using multiple regression models, this study explored the relationship between agreeableness, extraversion, stressor and stress response and figured out interactive effect of agreeableness, extraversion, and stressor on stress response. We draw on the following conclusions: (1) the interaction term of stressor (work) and agreeableness can negatively predict physiological stress response; (2) the interaction term of stresso...

  17. Stress responses in probiotic Lactobacillus casei.

    Science.gov (United States)

    Hosseini Nezhad, Marzieh; Hussain, Malik Altaf; Britz, Margaret Lorraine

    2015-01-01

    Survival in harsh environments is critical to both the industrial performance of lactic acid bacteria (LAB) and their competitiveness in complex microbial ecologies. Among the LAB, members of the Lactobacillus casei group have industrial applications as acid-producing starter cultures for milk fermentations and as specialty cultures for the intensification and acceleration of flavor development in certain bacterial-ripened cheese varieties. They are amongst the most common organisms in the gastrointestinal (GI) tract of humans and other animals, and have the potential to function as probiotics. Whether used in industrial or probiotic applications, environmental stresses will affect the physiological status and properties of cells, including altering their functionality and biochemistry. Understanding the mechanisms of how LAB cope with different environments is of great biotechnological importance, from both a fundamental and applied perspective: hence, interaction between these strains and their environment has gained increased interest in recent years. This paper presents an overview of the important features of stress responses in Lb. casei, and related proteomic or gene expression patterns that may improve their use as starter cultures and probiotics.

  18. Neuronal responses to physiological stress

    OpenAIRE

    Konstantinos eKagias; Camilla eNehammer; Roger ePocock

    2012-01-01

    Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. Physiological stress can be divided into three different aspects: environmental stress, intrinsic developmental stress and aging. Throughout life all living organisms are challenged by changes in the environment. Fluctuations in oxygen levels, temperature and redox state for example, trigger molecular events that enable an organism to adapt, survive and reproduce...

  19. Plant Core Environmental Stress Response Genes Are Systemically Coordinated during Abiotic Stresses

    Directory of Open Access Journals (Sweden)

    Kenneth W. Berendzen

    2013-04-01

    Full Text Available Studying plant stress responses is an important issue in a world threatened by global warming. Unfortunately, comparative analyses are hampered by varying experimental setups. In contrast, the AtGenExpress abiotic stress experiment displays intercomparability. Importantly, six of the nine stresses (wounding, genotoxic, oxidative, UV-B light, osmotic and salt can be examined for their capacity to generate systemic signals between the shoot and root, which might be essential to regain homeostasis in Arabidopsis thaliana. We classified the systemic responses into two groups: genes that are regulated in the non-treated tissue only are defined as type I responsive and, accordingly, genes that react in both tissues are termed type II responsive. Analysis of type I and II systemic responses suggest distinct functionalities, but also significant overlap between different stresses. Comparison with salicylic acid (SA and methyl-jasmonate (MeJA responsive genes implies that MeJA is involved in the systemic stress response. Certain genes are predominantly responding in only one of the categories, e.g., WRKY genes respond mainly non-systemically. Instead, genes of the plant core environmental stress response (PCESR, e.g., ZAT10, ZAT12, ERD9 or MES9, are part of different response types. Moreover, several PCESR genes switch between the categories in a stress-specific manner.

  20. Stress responses and pre-eclampsia.

    Science.gov (United States)

    Redman, C W G

    2013-04-01

    Biological stress may affect individual cells, tissues or whole organisms, arising from disturbed homoeostasis of any cause. Stress is rarely localised. Because biological systems are closely integrated, it spreads to involve other systems. Stress responses are highly integrated and work to restore homoeostasis. Different response pathways overlap and interlink. If the responses fail or decompensate, distress ensues, of which the end-stage is death. Pre-eclampsia results from a series of biological stresses, possibly from conception, which become established by abnormal placentation and affect the mother, her foetus and her placenta. The stresses involve dialogue between mother and placenta. Even a normal placenta imposes substantial stress on maternal systems. When placental growth and perfusion is abnormal (poor placentation) then the placenta, particularly its outer trophoblast layer, becomes stressed - loosely denoted hypoxic damage or oxidative stress. Signals from the placenta spread the stress to the mother, who develops signs of pre-eclampsia. Cellular stress sensors initiate stress responses. Different stresses may trigger similar responses in specific cell types. The first cell response is reduced protein synthesis. However some synthetic pathways are spared or activated to produce stress signals. In relation to pre-eclampsia and the placenta, an excessive release of sFlt-1 a soluble decoy receptor for vascular endothelial growth factor (VEGF) is a trophoblast related stress signal. SFlt1 perturbs the angiogenic balance in the maternal circulation and is considered to cause many of the specific features of the maternal syndrome in pre-eclampsia. Three key points will be emphasised. First, multiple stressors, not simply hypoxia, stimulate the release of sFlt-1 from trophoblast. Second, sFlt-1 is only one of the group of stress signals delivered by trophoblast to the mother. Third, sFlt-1 is not the only trophoblast derived factor to perturb the maternal

  1. Induction of aromatic amino acids and phenylpropanoid compounds in Scrophularia striata Boiss. cell culture in response to chitosan-induced oxidative stress.

    Science.gov (United States)

    Kamalipourazad, Maryam; Sharifi, Mohsen; Maivan, Hassan Zare; Behmanesh, Mehrdad; Chashmi, Najmeh Ahmadian

    2016-10-01

    Manipulation of cell culture media by elicitors is one of most important strategies to inducing secondary metabolism for the production of valuable metabolites. In this investigation, inducing effect of chitosan on physiological, biochemical, and molecular parameters were investigated in cell suspension cultures of Scrophularia striata Boiss. The results showed that chitosan concentration and time of elicitation are determinants of the effectiveness of the elicitor. Accumulation of aromatic amino acids (phenylalanine [Phe] and tyrosine [Tyr]), phenylpropanoid compounds (phenolic acids [PAs] and echinacoside [ECH]), hydrogen peroxide (H2O2) production, phenylalanine ammonia-lyase (PAL) activity and gene expression, and antioxidant enzymes (superoxide dismutase [SOD], peroxidase [POX], catalase [CAT]) activities were altered by changing the exposure time of elicitation. Results showed that, upon elicitation with chitosan, oxidative events were induced, antioxidant responses of S. striata cells were boosted through enhanced activity of an effective series of scavenging enzymes (SOD, CAT, and POX), and biosynthesis of non-enzymatic antioxidants (ECH and PAs [cinnamic, p-coumaric and, caffeic acids]). The increase in amino acid content and PAL activity at early days of exposure to chitosan was related with rises in phenolic compounds. These results provide evidence that chitosan by up-regulation of PAL gene differentially improves the production of phenylpropanoid compounds, which are of medical commercial value with good biotechnological prospects.

  2. Induction of aromatic amino acids and phenylpropanoid compounds in Scrophularia striata Boiss. cell culture in response to chitosan-induced oxidative stress.

    Science.gov (United States)

    Kamalipourazad, Maryam; Sharifi, Mohsen; Maivan, Hassan Zare; Behmanesh, Mehrdad; Chashmi, Najmeh Ahmadian

    2016-10-01

    Manipulation of cell culture media by elicitors is one of most important strategies to inducing secondary metabolism for the production of valuable metabolites. In this investigation, inducing effect of chitosan on physiological, biochemical, and molecular parameters were investigated in cell suspension cultures of Scrophularia striata Boiss. The results showed that chitosan concentration and time of elicitation are determinants of the effectiveness of the elicitor. Accumulation of aromatic amino acids (phenylalanine [Phe] and tyrosine [Tyr]), phenylpropanoid compounds (phenolic acids [PAs] and echinacoside [ECH]), hydrogen peroxide (H2O2) production, phenylalanine ammonia-lyase (PAL) activity and gene expression, and antioxidant enzymes (superoxide dismutase [SOD], peroxidase [POX], catalase [CAT]) activities were altered by changing the exposure time of elicitation. Results showed that, upon elicitation with chitosan, oxidative events were induced, antioxidant responses of S. striata cells were boosted through enhanced activity of an effective series of scavenging enzymes (SOD, CAT, and POX), and biosynthesis of non-enzymatic antioxidants (ECH and PAs [cinnamic, p-coumaric and, caffeic acids]). The increase in amino acid content and PAL activity at early days of exposure to chitosan was related with rises in phenolic compounds. These results provide evidence that chitosan by up-regulation of PAL gene differentially improves the production of phenylpropanoid compounds, which are of medical commercial value with good biotechnological prospects. PMID:27392152

  3. Feeding rumen-protected gamma-aminobutyric acid enhances the immune response and antioxidant status of heat-stressed lactating dairy cows.

    Science.gov (United States)

    Cheng, Jianbo; Zheng, Nan; Sun, Xianzhi; Li, Songli; Wang, Jiaqi; Zhang, Yangdong

    2016-08-01

    This experiment was conducted to investigate the effects of rumen-protected gamma-aminobutyric acid (GABA) on immune function and antioxidant status in heat-stressed dairy cows. Sixty Holstein dairy cows were randomly assigned to 1 of 4 treatments according to a completely randomized block design. The treatments consisted of 0 (control), 40, 80, or 120mg of GABA/kg DM from rumen-protected GABA. The trial lasted 10 weeks. The average temperature-humidity indices at 0700, 1400 and 2200h were 78.4, 80.2 and 78.7, respectively. Rectal temperatures decreased linearly at 0700, 1400, and 2200h with increasing GABA. As the GABA increased, the immunoglobulin (Ig) A and IgG contents and the proportions of CD4(+) and CD8(+) T lymphocytes increased linearly (PAOC) increased linearly (P<0.05), whereas malondialdehyde (MDA) content decreased linearly (P<0.05) with increasing GABA. These results indicate that rumen-protected GABA supplementation to heat-stressed dairy cows can improve their immune function and antioxidant activity. PMID:27503722

  4. Neuronal Responses to Physiological Stress

    OpenAIRE

    Kagias, Konstantinos; Nehammer, Camilla; Pocock, Roger

    2012-01-01

    Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. It can be divided into three different aspects: environmental stress, intrinsic developmental stress, and aging. Throughout life all living organisms are challenged by changes in the environment. Fluctuations in oxygen levels, temperature, and redox state for example, trigger molecular events that enable an organism to adapt, survive, and reproduce. In addition t...

  5. Stress Generation and Adolescent Depression: Contribution of Interpersonal Stress Responses

    OpenAIRE

    Flynn, Megan; Rudolph, Karen D.

    2011-01-01

    This research examined the proposal that ineffective responses to common interpersonal problems disrupt youths’ relationships, which, in turn, contributes to depression during adolescence. Youth (86 girls, 81 boys; M age = 12.41, SD = 1.19) and their primary female caregivers participated in a three-wave longitudinal study. Youth completed a measure assessing interpersonal stress responses; youth and caregivers completed semi-structured interviews assessing youths’ life stress and psychopatho...

  6. General Stress Responses in the Honey Bee

    Directory of Open Access Journals (Sweden)

    Naïla Even

    2012-12-01

    Full Text Available The biological concept of stress originated in mammals, where a “General Adaptation Syndrome” describes a set of common integrated physiological responses to diverse noxious agents. Physiological mechanisms of stress in mammals have been extensively investigated through diverse behavioral and physiological studies. One of the main elements of the stress response pathway is the endocrine hypothalamo-pituitary-adrenal (HPA axis, which underlies the “fight-or-flight” response via a hormonal cascade of catecholamines and corticoid hormones. Physiological responses to stress have been studied more recently in insects: they involve biogenic amines (octopamine, dopamine, neuropeptides (allatostatin, corazonin and metabolic hormones (adipokinetic hormone, diuretic hormone. Here, we review elements of the physiological stress response that are or may be specific to honey bees, given the economical and ecological impact of this species. This review proposes a hypothetical integrated honey bee stress pathway somewhat analogous to the mammalian HPA, involving the brain and, particularly, the neurohemal organ corpora cardiaca and peripheral targets, including energy storage organs (fat body and crop. We discuss how this system can organize rapid coordinated changes in metabolic activity and arousal, in response to adverse environmental stimuli. We highlight physiological elements of the general stress responses that are specific to honey bees, and the areas in which we lack information to stimulate more research into how this fascinating and vital insect responds to stress.

  7. Stress-induced biosynthesis of dicaffeoylquinic acids in globe artichoke.

    Science.gov (United States)

    Moglia, Andrea; Lanteri, Sergio; Comino, Cinzia; Acquadro, Alberto; de Vos, Ric; Beekwilder, Jules

    2008-09-24

    Leaf extracts from globe artichoke ( Cynara cardunculus L. var. scolymus) have been widely used in medicine as hepatoprotectant and choleretic agents. Globe artichoke leaves represent a natural source of phenolic acids with dicaffeoylquinic acids, such as cynarin (1,3-dicaffeoylquinic acid), along with its biosynthetic precursor chlorogenic acid (5-caffeoylquinic acid) as the most abundant molecules. This paper reports the development of an experimental system to induce caffeoylquinic acids. This system may serve to study the regulation of the biosynthesis of (poly)phenolic compounds in globe artichoke and the genetic basis of this metabolic regulation. By means of HPLC-PDA and accurate mass LC-QTOF MS and MS/MS analyses, the major phenolic compounds in globe artichoke leaves were identified: four isomers of dicaffeoylquinic acid, three isomers of caffeoylquinic acid, and the flavone luteolin 7-glucoside. Next, plant material was identified in which the concentration of phenolic compounds was comparable in the absence of particular treatments, with the aim to use this material to test the effect of stress application on the regulation of biosynthesis of caffeoylquinic acids. Using this material, the effect of UV-C, methyl jasmonate, and salicylic acid treatments on (poly)phenolic compounds was tested in different globe artichoke genotypes. UV-C exposure consistently increased the levels of dicaffeoylquinic acids in all genotypes, whereas the effect on compounds from the same biosynthetic pathway, for example, chlorogenic acid and luteolin-7-glucoside, was much less pronounced and was not statistically significant. No effect of methyl jasmonate or salicylic acid was found. Time-response experiments indicated that the level of dicaffeoylquinic acids reached a maximum at 24 h after UV radiation. On the basis of these results a role of dicaffeoylquinic acids in UV protection in globe artichoke is hypothesized. PMID:18710252

  8. Abiotic stressors and stress responses

    DEFF Research Database (Denmark)

    Sulmon, Cecile; Van Baaren, Joan; Cabello-Hurtado, Francisco;

    2015-01-01

    Abstract Organisms are regularly subjected to abiotic stressors related to increasing anthropogenic activities, including chemicals and climatic changes that induce major stresses. Based on various key taxa involved in ecosystem functioning (photosynthetic microorganisms, plants, invertebrates), ...

  9. Role of auxin-responsive genes in biotic stress responses

    OpenAIRE

    Ghanashyam, Challa; Jain, Mukesh

    2009-01-01

    Although the phytohormone auxin has been implicated primarily in developmental processes, some recent studies suggest its involvement in stress/defense responses as well. Recently, we identified auxin-responsive genes and reported their comprehensive transcript profiling during various stages of development and abiotic stress responses in crop plant rice. The analysis revealed tissue-specific and overlapping expression profiles of auxin-responsive genes during various stages of reproductive d...

  10. Induction and Degradation of Phosphatidic Acid in the Response of Plants to Stresses%磷脂酸的诱导和降解在植物逆境响应中的作用

    Institute of Scientific and Technical Information of China (English)

    张洁; 樊若溪; 李唯奇

    2011-01-01

    磷脂酸(phosphatidic acid,PA)是植物中重要的脂质信号分子,被称为"脂质第二信使",参与多种逆境胁迫相关的信号传导途径.植物体内的PA可通过直接的磷脂酶D途径和间接的磷脂酶C途径产生.当植物受到胁迫刺激后,细胞内的PA含量会在几分钟内升高,在胁迫消失后经磷酸化作用形成甘油二酯焦磷酸降解,恢复到正常水平.本文结合当前国内外的研究进展,就膜脂中PA的诱导和降解在植物逆境响应中的作用进行探讨与展望.%Phosphatidic acid (PA) is an important lipid signal molecule and emerge as a lipid second messenger in plants involved in various biotic and abiotic stress conditions. Two signaling pathways are predominantly responsible for its formation. PA is directly formed via activation of phospholipase D, and indirectly via activation of a phospholipase C pathway. The level of PA increases after a wide variety of stress treatments and goes back to the normal level when the stresses disappear. The enhanced signal level of PA is rapidly attenuated through the formation of diacylglycerol pyrophosphate via phosphorylating PA. In this paper, we discussed the research progress on the function of induction and degradation of PA in the response of plants to stresses.

  11. Tomato ABSCISIC ACID STRESS RIPENING (ASR gene family revisited.

    Directory of Open Access Journals (Sweden)

    Ido Golan

    Full Text Available Tomato ABSCISIC ACID RIPENING 1 (ASR1 was the first cloned plant ASR gene. ASR orthologs were then cloned from a large number of monocot, dicot and gymnosperm plants, where they are mostly involved in response to abiotic (drought and salinity stress and fruit ripening. The tomato genome encodes five ASR genes: ASR1, 2, 3 and 5 encode low-molecular-weight proteins (ca. 110 amino acid residues each, whereas ASR4 encodes a 297-residue polypeptide. Information on the expression of the tomato ASR gene family is scarce. We used quantitative RT-PCR to assay the expression of this gene family in plant development and in response to salt and osmotic stresses. ASR1 and ASR4 were the main expressed genes in all tested organs and conditions, whereas ASR2 and ASR3/5 expression was two to three orders of magnitude lower (with the exception of cotyledons. ASR1 is expressed in all plant tissues tested whereas ASR4 expression is limited to photosynthetic organs and stamens. Essentially, ASR1 accounted for most of ASR gene expression in roots, stems and fruits at all developmental stages, whereas ASR4 was the major gene expressed in cotyledons and young and fully developed leaves. Both ASR1 and ASR4 were expressed in flower organs, with ASR1 expression dominating in stamens and pistils, ASR4 in sepals and petals. Steady-state levels of ASR1 and ASR4 were upregulated in plant vegetative organs following exposure to salt stress, osmotic stress or the plant abiotic stress hormone abscisic acid (ABA. Tomato plants overexpressing ASR1 displayed enhanced survival rates under conditions of water stress, whereas ASR1-antisense plants displayed marginal hypersensitivity to water withholding.

  12. Soybean toxin (SBTX impairs fungal growth by interfering with molecular transport, carbohydrate/amino acid metabolism and drug/stress responses.

    Directory of Open Access Journals (Sweden)

    Janne K S Morais

    Full Text Available Soybean toxin (SBTX is an antifungal protein from soybeans with broad inhibitory activity against the growth and filamentation of many fungi, including human and plant pathogenic species such as Candida albicans, Candida parapsilosis, Aspergillus niger, Penicillium herquei, Cercospora sojina and Cercospora kikuchii. Understanding the mechanism by which SBTX acts on fungi and yeasts may contribute to the design of novel antifungal drugs and/or the development of transgenic plants resistant to pathogens. To this end, the polymorphic yeast C. albicans was chosen as a model organism and changes in the gene expression profile of strain SC5314 upon exposure to SBTX were examined. Genes that were differentially regulated in the presence of SBTX were involved in glucose transport and starvation-associated stress responses as well as in the control of both the induction and repression of C. albicans hyphal formation. Transmission electron microscopy showed that C. albicans cells exposed to SBTX displayed severe signs of starvation and were heavily granulated. Our data were indicative of C. albicans cell starvation despite sufficient nutrient availability in the medium; therefore, it can be speculated that SBTX blocks nutrient uptake systems. Because neither the starvation signal nor the alkaline response pathway lead to the induction of hyphae, we hypothesise that conflicting signals are transmitted to the complex regulatory network controlling morphogenesis, eventually preventing the filamentation signal from reaching a significant threshold.

  13. Soybean toxin (SBTX) impairs fungal growth by interfering with molecular transport, carbohydrate/amino acid metabolism and drug/stress responses.

    Science.gov (United States)

    Morais, Janne K S; Bader, Oliver; Weig, Michael; Oliveira, Jose Tadeu A; Arantes, Mariana R; Gomes, Valdirene M; Da Cunha, Maura; Oliveira, Hermogenes D; Sousa, Daniele O B; Lourencao, Andre L; Vasconcelos, Ilka M

    2013-01-01

    Soybean toxin (SBTX) is an antifungal protein from soybeans with broad inhibitory activity against the growth and filamentation of many fungi, including human and plant pathogenic species such as Candida albicans, Candida parapsilosis, Aspergillus niger, Penicillium herquei, Cercospora sojina and Cercospora kikuchii. Understanding the mechanism by which SBTX acts on fungi and yeasts may contribute to the design of novel antifungal drugs and/or the development of transgenic plants resistant to pathogens. To this end, the polymorphic yeast C. albicans was chosen as a model organism and changes in the gene expression profile of strain SC5314 upon exposure to SBTX were examined. Genes that were differentially regulated in the presence of SBTX were involved in glucose transport and starvation-associated stress responses as well as in the control of both the induction and repression of C. albicans hyphal formation. Transmission electron microscopy showed that C. albicans cells exposed to SBTX displayed severe signs of starvation and were heavily granulated. Our data were indicative of C. albicans cell starvation despite sufficient nutrient availability in the medium; therefore, it can be speculated that SBTX blocks nutrient uptake systems. Because neither the starvation signal nor the alkaline response pathway lead to the induction of hyphae, we hypothesise that conflicting signals are transmitted to the complex regulatory network controlling morphogenesis, eventually preventing the filamentation signal from reaching a significant threshold.

  14. Process Control Minitoring by Stress Response

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.; Stahl, David A.

    2006-04-17

    Environmental contamination with a variety of pollutants hasprompted the development of effective bioremediation strategies. But howcan these processes be best monitored and controlled? One avenue underinvestigation is the development of stress response systems as tools foreffective and general process control. Although the microbial stressresponse has been the subject of intensive laboratory investigation, theenvironmental reflection of the laboratory response to specific stresseshas been little explored. However, it is only within an environmentalcontext, in which microorganisms are constantly exposed to multiplechanging environmental stresses, that there will be full understanding ofmicrobial adaptive resiliency. Knowledge of the stress response in theenvironment will facilitate the control of bioremediation and otherprocesses mediated by complex microbial communities.

  15. Stress, stress-induced cortisol responses, and eyewitness identification performance.

    Science.gov (United States)

    Sauerland, Melanie; Raymaekers, Linsey H C; Otgaar, Henry; Memon, Amina; Waltjen, Thijs T; Nivo, Maud; Slegers, Chiel; Broers, Nick J; Smeets, Tom

    2016-07-01

    In the eyewitness identification literature, stress and arousal at the time of encoding are considered to adversely influence identification performance. This assumption is in contrast with findings from the neurobiology field of learning and memory, showing that stress and stress hormones are critically involved in forming enduring memories. This discrepancy may be related to methodological differences between the two fields of research, such as the tendency for immediate testing or the use of very short (1-2 hours) retention intervals in eyewitness research, while neurobiology studies insert at least 24 hours. Other differences refer to the extent to which stress-responsive systems (i.e., the hypothalamic-pituitary-adrenal axis) are stimulated effectively under laboratory conditions. The aim of the current study was to conduct an experiment that accounts for the contemporary state of knowledge in both fields. In all, 123 participants witnessed a live staged theft while being exposed to a laboratory stressor that reliably elicits autonomic and glucocorticoid stress responses or while performing a control task. Salivary cortisol levels were measured to control for the effectiveness of the stress induction. One week later, participants attempted to identify the thief from target-present and target-absent line-ups. According to regression and receiver operating characteristic analyses, stress did not have robust detrimental effects on identification performance. Copyright © 2016 John Wiley & Sons, Ltd. © 2016 The Authors Behavioral Sciences & the Law Published by John Wiley & Sons Ltd. PMID:27417874

  16. Quinolinic Acid: Neurotoxin or Oxidative Stress Modulator?

    Directory of Open Access Journals (Sweden)

    Lenka Kubicova

    2013-10-01

    Full Text Available Quinolinic acid (2,3-pyridinedicarboxylic acid, QUIN is a well-known neurotoxin. Consequently, QUIN could produce reactive oxygen species (ROS. ROS are generated in reactions catalyzed by transition metals, especially iron (Fe. QUIN can form coordination complexes with iron. A combination of differential pulse voltammetry, deoxyribose degradation and Fe(II autoxidation assays was used for explorating ROS formation in redox reactions that are catalyzed by iron in QUIN-Fe complexes. Differential pulse voltammetry showed an anodic shift of the iron redox potential if iron was liganded by QUIN. In the H2O2/FeCl3/ascorbic acid variant of the deoxyribose degradation assay, the dose-response curve was U-shaped. In the FeCl3/ascorbic acid variant, QUIN unambiguously showed antioxidant effects. In the Fe(II autoxidation assay, QUIN decreased the rate of ROS production caused by Fe(II oxidation. Our study confirms that QUIN toxicity may be caused by ROS generation via the Fenton reaction. This, however, applies only for unnaturally high concentrations that were used in attempts to provide support for the neurotoxic effect. In lower concentrations, we show that by liganding iron, QUIN affects the Fe(II/Fe(III ratios that are beneficial to homeostasis. Our results support the notion that redox chemistry can contribute to explaining the hormetic dose-response effects.

  17. Response of Desulfovibrio vulgaris to Alkaline Stress

    Energy Technology Data Exchange (ETDEWEB)

    Stolyar, S.; He, Q.; He, Z.; Yang, Z.; Borglin, S.E.; Joyner, D.; Huang, K.; Alm, E.; Hazen, T.C.; Zhou, J.; Wall, J.D.; Arkin, A.P.; Stahl, D.A.

    2007-11-30

    The response of exponentially growing Desulfovibrio vulgarisHildenborough to pH 10 stress was studied using oligonucleotidemicroarrays and a study set of mutants with genes suggested by microarraydata to be involved in the alkaline stress response deleted. The datashowed that the response of D. vulgaris to increased pH is generallysimilar to that of Escherichia coli but is apparently controlled byunique regulatory circuits since the alternative sigma factors (sigma Sand sigma E) contributing to this stress response in E. coli appear to beabsent in D. vulgaris. Genes previously reported to be up-regulated in E.coli were up-regulated in D. vulgaris; these genes included three ATPasegenes and a tryptophan synthase gene. Transcription of chaperone andprotease genes (encoding ATP-dependent Clp and La proteases and DnaK) wasalso elevated in D. vulgaris. As in E. coli, genes involved in flagellumsynthesis were down-regulated. The transcriptional data also identifiedregulators, distinct from sigma S and sigma E, that are likely part of aD. vulgaris Hildenborough-specific stress response system.Characterization of a study set of mutants with genes implicated inalkaline stress response deleted confirmed that there was protectiveinvolvement of the sodium/proton antiporter NhaC-2, tryptophanase A, andtwo putative regulators/histidine kinases (DVU0331 andDVU2580).

  18. Stress Response and Recovery in Atlantic Salmon (Salmo salar L.) Fed Diets Low in the Marine n-3 Fatty Acids EPA and DHA

    OpenAIRE

    Cai, Chan

    2014-01-01

    With the fast growth of today's aquaculture industry, the demand for aquafeeds is expanding dramatically. Finding sustainable alternative sources to fishmeal and fish oil (FO) is becoming an urgent issue; vegetable oil (VO) and plant meal are potential candidates. Replacing the fishmeal and FO with plant materials means fish eat low levels of polyunsaturated fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); this may affect the fish growth and health such as s...

  19. Neuroendocrine Stress Response after Burn Trauma

    OpenAIRE

    Lindahl, Andreas

    2013-01-01

    Some aspects of the stress response during acute intensive care for severe burns are described and quantified by measuring hormonal and neuroendocrine patterns and relating these to organ function in the short term. This includes an assessment of whether there are markers for the severity of stress that are better than conventional descriptors of the severity of a burn in predicting failing organ function. P-CgA after a major burn injury is an independent and better predictor of organ dysfunc...

  20. Prenatal Stress Enhances Responsiveness to Cocaine

    OpenAIRE

    Kippin, Tod E.; Szumlinski, Karen K.; Kapasova, Zuzana; Rezner, Betsy; See, Ronald E.

    2007-01-01

    Early environmental events have profound influences on a wide range of adult behavior. In the current study, we assessed the influence of maternal stress during gestation on psychostimulant and neurochemical responsiveness to cocaine, cocaine self-administration, and reinstatement of cocaine-seeking in adult offspring. Pregnant, female Sprague–Dawley rats were subjected to either no treatment or to restraint stress three times per day for the last 7 days of gestation and cocaine-related behav...

  1. Endocannabinoids and the cardiovascular response to stress.

    Science.gov (United States)

    O'Sullivan, Saoirse E; Kendall, Patrick J; Kendall, David A

    2012-01-01

    Stress activates the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS), resulting in cardiovascular responses. The endocannabinoid system (ECS), a ubiquitously expressed lipid signalling system, modulates both HPA and SNS activity. The purpose of this review is to explore the possible involvement/role of the ECS in the cardiovascular response to stress. The ECS has numerous cardiovascular effects including modulation of blood pressure, heart rate, the baroreflex, and direct vascular actions. It is also involved in a protective manner in response to stressors in cardiac preconditioning, and various stressors (for example, pain, orthostasis and social stress) increase plasma levels of endocannabinoids. Given the multitude of vascular effects of endocannabinoids, this is bound to have consequences. Beneficial effects of ECS upregulation could include cardioprotection, vasodilatation, CB(2)-mediated anti-inflammatory effects and activation of peroxisome proliferator-activated receptors. Negative effects of endocannabinoids could include mediation of the effects of glucocorticoids, CB(1)-mediated metabolic changes, and metabolism to vasoconstrictor products. It is also likely that there is a central role for the ECS in modulating cardiovascular activity via the HPA and SNS. However, much more work is required to fully integrate the role of the ECS in mediating many of the physiological responses to stress, including cardiovascular responses.

  2. The transcriptional regulatory network in the drought response and its crosstalk in abiotic stress responses including drought, cold, and heat

    OpenAIRE

    Nakashima, Kazuo; Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

    2014-01-01

    Drought negatively impacts plant growth and the productivity of crops around the world. Understanding the molecular mechanisms in the drought response is important for improvement of drought tolerance using molecular techniques. In plants, abscisic acid (ABA) is accumulated under osmotic stress conditions caused by drought, and has a key role in stress responses and tolerance. Comprehensive molecular analyses have shown that ABA regulates the expression of many genes under osmotic stress cond...

  3. Dysfunctional stress responses in chronic pain.

    Science.gov (United States)

    Woda, Alain; Picard, Pascale; Dutheil, Frédéric

    2016-09-01

    Many dysfunctional and chronic pain conditions overlap. This review describes the different modes of chronic deregulation of the adaptive response to stress which may be a common factor for these conditions. Several types of dysfunction can be identified within the hypothalamo-pituitary-adrenal axis: basal hypercortisolism, hyper-reactivity, basal hypocortisolism and hypo-reactivity. Neuroactive steroid synthesis is another component of the adaptive response to stress. Dehydroepiandrosterone (DHEA) and its sulfated form DHEA-S, and progesterone and its derivatives are synthetized in cutaneous, nervous, and adipose cells. They are neuroactive factors that act locally. They may have a role in the localization of the symptoms and their levels can vary both in the central nervous system and in the periphery. Persistent changes in neuroactive steroid levels or precursors can induce localized neurodegeneration. The autonomic nervous system is another component of the stress response. Its dysfunction in chronic stress responses can be expressed by decreased basal parasympathethic activity, increased basal sympathetic activity or sympathetic hyporeactivity to a stressful stimulus. The immune and genetic systems also participate. The helper-T cells Th1 secrete pro-inflammatory cytokines such as IL-1-β, IL-2, IL-6, IL-8, IL-12, IFN-γ, and TNF-α, whereas Th2 secrete anti-inflammatory cytokines: IL-4, IL-10, IGF-10, IL-13. Chronic deregulation of the Th1/Th2 balance can occur in favor of anti- or pro-inflammatory direction, locally or systemically. Individual vulnerability to stress can be due to environmental factors but can also be genetically influenced. Genetic polymorphisms and epigenetics are the main keys to understanding the influence of genetics on the response of individuals to constraints. PMID:27262345

  4. Dynamics of active cellular response under stress

    Science.gov (United States)

    de, Rumi; Zemel, Assaf; Safran, Samuel

    2008-03-01

    Forces exerted by and on adherent cells are important for many physiological processes such as wound healing and tissue formation. In addition, recent experiments have shown that stem cell differentiation is controlled, at least in part, by the elasticity of the surrounding matrix. Using a simple theoretical model that includes the forces due to both the mechanosensitive nature of cells and the elastic response of the matrix, we predict the dynamics of orientation of cells. The model predicts many features observed in measurements of cellular forces and orientation including the increase with time of the forces generated by cells in the absence of applied stress and the consequent decrease of the force in the presence of quasi-static stresses. We also explain the puzzling observation of parallel alignment of cells for static and quasi-static stresses and of nearly perpendicular alignment for dynamically varying stresses. In addition, we predict the response of the cellular orientation to a sinusoidally varying applied stress as a function of frequency. The dependence of the cell orientation angle on the Poisson ratio of the surrounding material can be used to distinguish systems in which cell activity is controlled by stress from those where cell activity is controlled by strain. Reference: Nature Physics, vol. 3, pp 655 (2007).

  5. Phosphatidic acid, a versatile water-stress signal in roots

    Directory of Open Access Journals (Sweden)

    Fionn eMcLoughlin

    2013-12-01

    Full Text Available Adequate water supply is of utmost importance for growth and reproduction of plants. In order to cope with water deprivation, plants have to adapt their development and metabolism to ensure survival. To maximize water use efficiency, plants use a large array of signaling mediators such as hormones, protein kinases and phosphatases, Ca2+, reactive oxygen species and low abundant phospholipids that together form complex signaling cascades. Phosphatidic acid (PA is a signaling lipid that rapidly accumulates in response to a wide array of abiotic stress stimuli. PA formation provides the cell with spatial and transient information about the external environment by acting as a protein-docking site in cellular membranes. PA reportedly binds to a number of proteins that play a role during water limiting conditions, such as drought and salinity and has been shown to play an important role in maintaining root system architecture. Members of two osmotic stress-activated protein kinase families, sucrose non-fermenting 1-related protein kinase 2 (SnRK2 and mitogen activated protein kinases (MAPKs were recently shown bind PA and are also involved in the maintenance of root system architecture and salinity stress tolerance. In addition, PA regulates several proteins involved in abscisic acid (ABA-signaling. PA-dependent recruitment of glyceraldehyde-3-phosphate dehydrogenase (GAPDH under water limiting conditions indicates a role in regulating metabolic processes. Finally, a recent study also shows the PA recruits the clathrin heavy chain and a potassium channel subunit, hinting towards additional roles in cellular trafficking and potassium homeostasis. Taken together, the rapidly increasing number of proteins reported to interact with PA implies a broad role for this versatile signaling phospholipid in mediating salt and water stress responses.

  6. Two Lactococcus lactis thioredoxin paralogues play different roles in responses to arsenate and oxidative stress

    DEFF Research Database (Denmark)

    Efler, Petr; Kilstrup, Mogens; Johnsen, Stig;

    2015-01-01

    Thioredoxin (Trx) maintains intracellular thiol groups in a reduced state and is involved in a wide range of cellular processes, including ribonucleotide reduction, sulphur assimilation, oxidative stress responses and arsenate detoxification. The industrially important lactic acid bacterium Lacto...

  7. Corporate Responsibility for Systemic Occupational Stress Prevention

    Directory of Open Access Journals (Sweden)

    R. Kasperczyk

    2014-09-01

    Full Text Available The purpose of this paper is twofold: to highlight the increased focus on corporate governance responsibility for managing employees’ psychological health, and to present an argument for a systemic approach to prevention of occupational stress. The paper commences with a brief description of the problem posed by occupational stress as a threat to organisational effectiveness. It then discusses the types of currently observed organisational responses to this issue and the extent to which they are shaped by beliefs about occupational stress. There are two fundamental approaches to dealing with work stress, one aimed at the individual and the other, at the organisation. The more comprehensive approaches have been increasingly reported to be more effective. The argument for a systemic approach to its prevention is then developed, in line with the risk management framework currently being adopted by Government jurisdictions governing Occupational Health and Safety in Australia and New Zealand. As the stress issue is now couched in health and safety terms, it is a moral and legal duty of the Board to satisfy itself that it is effectively addressed.

  8. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress

    OpenAIRE

    Lin Zhou; Hui Xu; Sue Mischke; Meinhardt, Lyndel W.; Dapeng Zhang; Xujun Zhu; Xinghui Li; Wanping Fang

    2014-01-01

    Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant under drought stress is essential to develop drought-tolerant tea genotypes, along with crop management practices that can mitigate drought stress. The objective of the present investigation is evaluat...

  9. Transcriptome Analysis of Enterococcus faecalis in Response to Alkaline Stress

    Directory of Open Access Journals (Sweden)

    Ran eshujun

    2015-08-01

    Full Text Available E. faecalis is the most commonly isolated species from endodontic failure root canals; its persistence in treated root canals has been attributed to its ability to resist high pH stress. The goal of this study was to characterize the E. faecalis transcriptome and to identify candidate genes for response and resistance to alkaline stress using Illumina HiSeq 2000 sequencing.We found that E. faecalis could survive and form biofilms in a pH 10 environment and that alkaline stress had a great impact on the transcription of many genes in the E. faecalis genome. The transcriptome sequencing results revealed that 613 genes were differentially expressed (DEGs for E. faecalis grown in pH 10 medium; 211 genes were found to be differentially up-regulated and 402 genes differentially down-regulated. Many of the down-regulated genes found are involved in cell energy production and metabolism and carbohydrate and amino acid metabolism, and the up-regulated genes are mostly related to nucleotide transport and metabolism. The results presented here reveal that cultivation of E. faecalis in alkaline stress has a profound impact on its transcriptome. The observed regulation of genes and pathways revealed that E. faecalis reduced its carbohydrate and amino acid metabolism and increased nucleotide synthesis to adapt and grow in alkaline stress. A number of the regulated genes may be useful candidates for the development of new therapeutic approaches for the treatment of E. faecalis infections.

  10. Transcriptional Regulation of Arabidopsis in Response to Salt Stress

    Institute of Scientific and Technical Information of China (English)

    Zhulong Chan

    2012-01-01

    biotic stress related genes were significantly changed by Sha ecotype effect.Several metabolic pathways such as tricarboxylic acid cycle and redox,and the Gene Ontology terms involved in oxidation and defense response were enriched by both salinity and ecotype effects.All these results indicated that the all transgenic plants and Sha ecotype were possibly preconditioned to salt stress.These comparative transcriptomic and analytical results also confirm the complexity of salt stress tolerance mechanisms,and they suggest additional targets for improving tolerance.

  11. The Effect of Acid Stress Treatment on Viability and Membrane Fatty Acid Composition of Oenococcus oeni SD-2a

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen-ying; LI Hua; WANG Hua; LI Zhong-chao; WANG Ai-lian

    2009-01-01

    To obtain ready-to-use wine malolactic starter cultures with high viability, the effects of acid stress treatments on the growth, inoculation viability, freeze-drying viability, and membrane fatty acid composition of the native Oenococcus oeni SD-2a strain were studied. The results showed that pH 3.5 and 3.2 adaptive treatments did not strongly decrease cell biomass but increased distinctly inoculation viability and freeze-drying viability. Concerning the membrane fatty acid composition, it was observed that acid stress conditions increased significantly the relative concentration of lactobacillic acid (C19cycl 1) and the unsaturated:saturated fatty acid ratio in cell membrane lipids. We assumed that acid-induced cross protective responses could be used in preparing ready-to-use O. oeni SD-2a malolactic starter cultures, and the accumulation of lactobacillic acid in the membrane of O. oeni SD-2a cells appears as an acid stress response mechanism,which might be related with the enhanced viability.

  12. Polyunsaturated Branched-Chain Fatty Acid Geranylgeranoic Acid Induces Unfolded Protein Response in Human Hepatoma Cells.

    Directory of Open Access Journals (Sweden)

    Chieko Iwao

    Full Text Available The acyclic diterpenoid acid geranylgeranoic acid (GGA has been reported to induce autophagic cell death in several human hepatoma-derived cell lines; however, the molecular mechanism for this remains unknown. In the present study, several diterpenoids were examined for ability to induce XBP1 splicing and/or lipotoxicity for human hepatoma cell lines. Here we show that three groups of diterpenoids emerged: 1 GGA, 2,3-dihydro GGA and 9-cis retinoic acid induce cell death and XBP1 splicing; 2 all-trans retinoic acid induces XBP1 splicing but little cell death; and 3 phytanic acid, phytenic acid and geranylgeraniol induce neither cell death nor XBP1 splicing. GGA-induced ER stress/ unfolded protein response (UPR and its lipotoxicity were both blocked by co-treatment with oleic acid. The blocking activity of oleic acid for GGA-induced XBP1 splicing was not attenuated by methylation of oleic acid. These findings strongly suggest that GGA at micromolar concentrations induces the so-called lipid-induced ER stress response/UPR, which is oleate-suppressive, and shows its lipotoxicity in human hepatoma cells.

  13. Influence of omega-3 fatty acid status on the way rats adapt to chronic restraint stress.

    Directory of Open Access Journals (Sweden)

    Marie Hennebelle

    Full Text Available Omega-3 fatty acids are important for several neuronal and cognitive functions. Altered omega-3 fatty acid status has been implicated in reduced resistance to stress and mood disorders. We therefore evaluated the effects of repeated restraint stress (6 h/day for 21 days on adult rats fed omega-3 deficient, control or omega-3 enriched diets from conception. We measured body weight, plasma corticosterone and hippocampus glucocorticoid receptors and correlated these data with emotional and depression-like behaviour assessed by their open-field (OF activity, anxiety in the elevated-plus maze (EPM, the sucrose preference test and the startle response. We also determined their plasma and brain membrane lipid profiles by gas chromatography. Repeated restraint stress caused rats fed a control diet to lose weight. Their plasma corticosterone increased and they showed moderate behavioural changes, with increases only in grooming (OF test and entries into the open arms (EPM. Rats fed the omega-3 enriched diet had a lower stress-induced weight loss and plasma corticosterone peak, and reduced grooming. Rats chronically lacking omega-3 fatty acid exhibited an increased startle response, a stress-induced decrease in locomotor activity and exaggerated grooming. The brain omega-3 fatty acids increased as the dietary omega-3 fatty acids increased; diets containing preformed long-chain omega-3 fatty acid were better than diets containing the precursor alpha-linolenic acid. However, the restraint stress reduced the amounts of omega-3 incorporated. These data showed that the response to chronic restraint stress was modulated by the omega-3 fatty acid supply, a dietary deficiency was deleterious while enrichment protecting against stress.

  14. The Progress of Proteomics Technology and Its Application in Lactic Acid Bacteria's Responses to Environmental Stress%蛋白组学技术在乳酸菌环境胁迫应激研究中的应用

    Institute of Scientific and Technical Information of China (English)

    周方方; 吴正钧; 艾连中; 刘振民

    2012-01-01

    文中介绍了蛋白质组学新技术原理及常用技术路线,着重论述了该技术对乳酸菌在各种不同环境胁迫应激研究中的应用,从酸胁迫、冷胁迫、胆盐胁迫、渗透压胁迫及氧化胁迫等方面分别做了应用分析,并对该技术在分子生物学领域尤其是乳酸菌分子生物学研究方面未来的发展做了展望。%The progress of proteomics technology was reviewed in this paper. The application of proteomics tech- nology to analyze the response of lactic acid bacteria to environmental stress was also summarized. The predominant environmental stress factors influencing the physiology of Lactic acid bacteria including acidity stress, cold stress, bile salt stress, osmotic stress and oxidative stress were discussed. Development and future direction were also suggested for proteomics technology in the field of molecular biology, especially in lactic acid bacteria molecular biology.

  15. Transcriptome Analysis of High-Temperature Stress in Developing Barley Caryopses :Early Stress Responses and Effects on Storage Compound Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Elke Mangelsen; Joachim Kilian; Klaus Harter; Christer Jansson; Dierk Wanke; Eva Sundberg

    2011-01-01

    High-temperature stress,like any abiotic stress,impairs the physiology and development of plants,including the stages of seed setting and ripening.We used the Aflymetrix 22K Barley1 GeneChip microarray to investigate the response of developing barley(Hordeum vulgare)seeds,termed caryopses,after 0.5,3,and 6 h of heat stress exposure;958 induced and 1122 repressed genes exhibited spatial and temporal expression patterns that provide a detailed insight into the caryopses'early heat stress responses.Down-regulation of genes related to storage compound biosynthesis and cell growth provides evidence for a rapid impairment of the caryopsis' development.Increased levels of sugars and amino acids were indicative for both production of compatible solutes and feedback-induced accumulation of substrates for storage compound biosynthesis.Metadata analysis identified embryo and endosperm as primary locations of heat stress responses,indicating a strong impact of short-term heat stress on central developmental functions of the caryopsis.A comparison with heat stress responses in Arabidopsis shoots and drought stress responses in barley caryopses identified both conserved and presumably heat-and caryopsis-specific stress-responsive genes.Summarized,our data provide an important basis for further investigation of gene functions in order to aid an improved heat tolerance and reduced losses of yield in barley as a model for cereal crops.

  16. Physiological Responses to Thermal Stress and Exercise

    Science.gov (United States)

    Iyota, Hiroyuki; Ohya, Akira; Yamagata, Junko; Suzuki, Takashi; Miyagawa, Toshiaki; Kawabata, Takashi

    The simple and noninvasive measuring methods of bioinstrumentation in humans is required for optimization of air conditioning and management of thermal environments, taking into consideration the individual specificity of the human body as well as the stress conditions affecting each. Changes in human blood circulation were induced with environmental factors such as heat, cold, exercise, mental stress, and so on. In this study, the physiological responses of human body to heat stress and exercise were investigated in the initial phase of the developmental research. We measured the body core and skin temperatures, skin blood flow, and pulse wave as the indices of the adaptation of the cardiovascular system. A laser Doppler skin blood flowmetry using an optical-sensor with a small portable data logger was employed for the measurement. These results reveal the heat-stress and exercise-induced circulatory responses, which are under the control of the sympathetic nerve system. Furthermore, it was suggested that the activity of the sympathetic nervous system could be evaluated from the signals of the pulse wave included in the signals derived from skin blood flow by means of heart rate variability assessments and detecting peak heights of velocity-plethysmogram.

  17. Arabidopsis YAK1 regulates abscisic acid response and drought resistance.

    Science.gov (United States)

    Kim, Dongjin; Ntui, Valentine Otang; Xiong, Liming

    2016-07-01

    Abscisic acid (ABA) is an important phytohormone that controls several plant processes such as seed germination, seedling growth, and abiotic stress response. Here, we report that AtYak1 plays an important role in ABA signaling and postgermination growth in Arabidopsis. AtYak1 knockout mutant plants were hyposensitive to ABA inhibition of seed germination, cotyledon greening, seedling growth, and stomatal movement. atyak1-1 mutant plants display reduced drought stress resistance, as evidenced by water loss rate and survival rate. Molecular genetic analysis revealed that AtYak1 deficiency led to elevated expression of stomatal-related gene, MYB60, and down-regulation of several stress-responsive genes. Altogether, these results indicate that AtYak1 plays a role as a positive regulator in ABA-mediated drought response in Arabidopsis. PMID:27264339

  18. Long Term Salinity Stress Reveals Variety Specific Differences in Root Oxidative Stress Response

    Institute of Scientific and Technical Information of China (English)

    Prasad SENADHEERA; Shamala TIRIMANNE; Frans J M MAATHUIS

    2012-01-01

    Salinity stress induces oxidative stress caused by reactive oxygen species (ROS):superoxide radicals,hydrogen peroxide (H2O2) and hydroxyl radicals.Activities of both enzymatic and non-enzymatic components of the antioxidant system and related growth parameters were studied in the roots of the salt tolerant rice variety FL478 and the sensitive variety IR29 in response to long term stress (12 d) induced by 50 mmol/L NaCl.The comparative study showed that FL478maintained higher relative growth rate and lower Na+/K+ in the roots than IR29 due to a higher membrane stability index that effectively exclude Na+.Lower TBARS (thiobarbituric acid reactive substance) content in FL478 roots indicated that its membrane was relatively unaffected by ROS despite high H2O2 content recorded under the salinity stress.Relatively higher superoxide dismutase activity along with a parallel increase in transcript level of superoxide dismutase (Os07946990) in FL478 indicated that this protein might make a vital contribution to salt stress tolerance.Although the content of ascorbic acid remained unchanged in FL478,the activity of ascorbic peroxidases (APOXs) was reduced comparably in the both varieties.Transcriptomic data showed that a larger number of peroxidase genes were upregulated in FL478 compared to IR29 and several of which might provide engineering targets to improve rice salt tolerance.

  19. Stressed out? Associations between perceived and physiological stress responses in adolescents: The TRAILS study

    OpenAIRE

    Oldehinkel, Albertine J.; Ormel, Johan; Bosch, Nienke M.; Bouma, Esther M. C.; Van Roon, Arie M.; Rosmalen, Judith G. M.; Riese, Harriette

    2011-01-01

    Studies regarding the interrelation of perceived and physiological stress indices have shown diverging results. Using a population sample of adolescents (N=715, 50.9% girls, mean age 16.11 years, SD=0.59), we tested three hypotheses: (1) perceived responses during social stress covary with concurrent physiological stress responses; (2) high pretest levels of perceived stress predict large physiological responses; and (3) large physiological responses to social stress predict low posttest perc...

  20. Sorbic acid stress activates the Candida glabrata high osmolarity glycerol MAP kinase pathway

    Directory of Open Access Journals (Sweden)

    Zeljkica eJandric

    2013-11-01

    Full Text Available Weak organic acids such as sorbic acid are important food preservatives and powerful fungistatic agents. These compounds accumulate in the cytosol and disturb the cellular pH and energy homeostasis. Candida glabrata is in many aspects similar to Saccharomyces cerevisiae. However, with regard to confrontation to sorbic acid, two of the principal response pathways behave differently in Candida glabrata. In yeast, sorbic acid stress causes activation of many genes via the transcription factors Msn2 and Msn4. The C. glabrata homologues CgMsn2 and CgMsn4 are apparently not activated by sorbic acid. In contrast, in C. glabrata the high osmolarity glycerol (HOG pathway is activated by sorbic acid. Here we show that the MAP kinase of the HOG pathway, CgHog1, becomes phosphorylated and has a function for weak acid stress resistance. Transcript profiling of weak acid treated C. glabrata cells suggests a broad and very similar response pattern of cells lacking CgHog1 compared to wild type which is over lapping with but distinct from S. cerevisiae. The PDR12 gene was the highest induced gene in both species, and required CgHog1 for full expression. Our results support flexibility of the response cues for general stress signaling pathways, even between closely related yeasts, and functional extension of a specific response pathway.

  1. Neural and cardiovascular responses to emotional stress in humans

    OpenAIRE

    Carter, Jason R.; Durocher, John J.; Kern, Rosalie P.

    2008-01-01

    Sympathetic neural responses to mental stress are well documented but controversial, whereas sympathetic neural responses to emotional stress are unknown. The purpose of this study was to investigate neural and cardiovascular responses to emotional stress evoked by negative pictures and reexamine the relationship between muscle sympathetic nerve activity (MSNA) and perceived stress. Mean arterial pressure (MAP), heart rate (HR), MSNA, and perceived stress levels were recorded in 18 men during...

  2. The transcriptional regulatory network in the drought response and its crosstalk in abiotic stress responses including drought, cold and heat

    Directory of Open Access Journals (Sweden)

    Kazuo eNakashima

    2014-05-01

    Full Text Available Drought negatively impacts plant growth and the productivity of crops around the world. Understanding the molecular mechanisms in the drought response is important for improvement of drought tolerance using molecular techniques. In plants, abscisic acid (ABA is accumulated under osmotic stress conditions caused by drought, and has a key role in stress responses and tolerance. Comprehensive molecular analyses have shown that ABA regulates the expression of many genes under osmotic stress conditions, and the ABA-responsive element (ABRE is the major cis-element for ABA-responsive gene expression. Transcription factors (TFs are master regulators of gene expression. ABRE-binding protein (AREB and ABRE-binding factor (ABF TFs control gene expression in an ABA-dependent manner. SNF1-related protein kinases 2, group A 2C-type protein phosphatases, and ABA receptors were shown to control the ABA signaling pathway. ABA-independent signaling pathways such as dehydration-responsive element-binding protein (DREB TFs and NAC TFs are also involved in stress responses including drought, heat and cold. Recent studies have suggested that there are interactions between the major ABA signaling pathway and other signaling factors in stress responses. The important roles of these transcription factors in crosstalk among abiotic stress responses will be discussed. Control of ABA or stress signaling factor expression can improve tolerance to environmental stresses. Recent studies using crops have shown that stress-specific overexpression of TFs improves drought tolerance and grain yield compared with controls in the field.

  3. The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Wang, Zhenyu

    2011-05-01

    Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA biosynthesis, we screened for Arabidopsis thaliana mutants that failed to induce the NCED3 genee xpression in response to osmotic stress treatments. The ced1 (for 9-cis epoxycarotenoid dioxy genase defective 1) mutant isolated in this study showed markedly reduced expression of NCED3 in response to osmotic stress (polyethylene glycol)treatments compared with the wild type. Other ABA biosynthesis genes are also greatly reduced in ced1 under osmotic stress. ced1 mutant plants are very sensitive to even mild osmotic stress. Map-based cloning revealed unexpectedly thatCED1 encodes a putative a/b hydrolase domain-containing protein and is allelic to the BODYGUARD gene that was recently shown to be essential for cuticle biogenesis. Further studies discovered that other cut in biosynthesis mutants are also impaired in osmotic stress induction of ABA biosynthesis genes and are sensitive to osmotic stress. Our work demonstrates that the cuticle functions not merely as a physical barrier to minimize water loss but also mediates osmotic stress signaling and tolerance by regulating ABA biosynthesis and signaling. © 2011 American Society of Plant Biologists. All rights reserved.

  4. Stress response and apoptosis in pro- and antiinflammatory macrophages.

    Science.gov (United States)

    Malyshev, I Yu; Kruglov, S V; Bakhtina, L Yu; Malysheva, E V; Zubin, M; Norkin, M

    2004-08-01

    We showed that stress response and apoptosis in macrophages depend on the phenotype of their secretory activity and specific biological and physical characteristics of the factor inducing stress-response or apoptosis.

  5. Effects of organic acids on thermal inactivation of acid and cold stressed Enterococcus faecium.

    Science.gov (United States)

    Fernández, Ana; Alvarez-Ordóñez, Avelino; López, Mercedes; Bernardo, Ana

    2009-08-01

    In this study the adaptative response to heat (70 degrees C) of Enterococcus faecium using fresh and refrigerated (at 4 degrees C for up to 1 month) stationary phase cells grown in Brain Heart Infusion (BHI) buffered at pH 7.4 (non-acid-adapted cells) and acidified BHI at pH values of 6.4 and 5.4 with acetic, ascorbic, citric, lactic, malic and hydrochloric acids (acid-adapted cells) was evaluated. In all cases, the survival curves obtained were concave upward. A mathematical model based on the Weibull distribution accurately described the inactivation kinetic. The results indicate that previous adaptation to a low pH increased the bacterial heat resistance, whereas the subsequent cold storage of cells reduced E. faecium thermal tolerance. Fresh acid-adapted cells showed t(2.5)-values (time needed to obtain an inactivation level of 2.5 log10 cycles) ranging from 2.57 to 9.51 min, while non-acid-adapted cells showed t(2.5)-values of 1.92 min. The extent of increased heat tolerance varied with the acid examined, resulting in the following order: citric > or = acetic > malic > or = lactic > hydrochloric > or = ascorbic. In contrast, cold storage progressively decreased E. faecium thermal resistance. The t(2.5) values found at the end of the period studied were about 2-3-fold lower than those corresponding to non-refrigerated cells, although this decrease was more marked (about 5-fold) when cells were grown in buffered BHI and BHI acidified at pH 5.4 with hydrochloric acid. These findings highlight the need for a better understanding of microbial response to various preservation stresses in order to increase the efficiency of thermal processes and to indicate the convenience of counterbalancing the benefits of the hurdle concept.

  6. Repeated forced swim stress differentially affects formalin-evoked nociceptive behaviour and the endocannabinoid system in stress normo-responsive and stress hyper-responsive rat strains.

    Science.gov (United States)

    Jennings, Elaine M; Okine, Bright N; Olango, Weredeselam M; Roche, Michelle; Finn, David P

    2016-01-01

    Repeated exposure to a homotypic stressor such as forced swimming enhances nociceptive responding in rats. However, the influence of genetic background on this stress-induced hyperalgesia is poorly understood. The aim of the present study was to compare the effects of repeated forced swim stress on nociceptive responding in Sprague-Dawley (SD) rats versus the Wistar Kyoto (WKY) rat strain, a genetic background that is susceptible to stress, negative affect and hyperalgesia. Given the well-documented role of the endocannabinoid system in stress and pain, we investigated associated alterations in endocannabinoid signalling in the dorsal horn of the spinal cord and amygdala. In SD rats, repeated forced swim stress for 10 days was associated with enhanced late phase formalin-evoked nociceptive behaviour, compared with naive, non-stressed SD controls. In contrast, WKY rats exposed to 10 days of swim stress displayed reduced late phase formalin-evoked nociceptive behaviour. Swim stress increased levels of monoacylglycerol lipase (MAGL) mRNA in the ipsilateral side of the dorsal spinal cord of SD rats, an effect not observed in WKY rats. In the amygdala, swim stress reduced anandamide (AEA) levels in the contralateral amygdala of SD rats, but not WKY rats. Additional within-strain differences in levels of CB1 receptor and fatty acid amide hydrolase (FAAH) mRNA and levels of 2-arachidonylglycerol (2-AG) were observed between the ipsilateral and contralateral sides of the dorsal horn and/or amygdala. These data indicate that the effects of repeated stress on inflammatory pain-related behaviour are different in two rat strains that differ with respect to stress responsivity and affective state and implicate the endocannabinoid system in the spinal cord and amygdala in these differences.

  7. Immune responses to stress after stress management training in patients with rheumatoid arthritis

    OpenAIRE

    de Brouwer, Sabine JM; van Middendorp, Henriët; Kraaimaat, Floris W.; Radstake, Timothy RDJ; Joosten, Irma; Donders, A Rogier T; Eijsbouts, Agnes; Koulil, Saskia Spillekom-van; van Riel, Piet LCM; Evers, Andrea WM

    2013-01-01

    Introduction Psychological stress may alter immune function by activating physiological stress pathways. Building on our previous study, in which we report that stress management training led to an altered self-reported and cortisol response to psychological stress in patients with rheumatoid arthritis (RA), we explored the effects of this stress management intervention on the immune response to a psychological stress task in patients with RA. Methods In this study, 74 patients with RA, who w...

  8. The early stress responses in fish larvae.

    Science.gov (United States)

    Pederzoli, Aurora; Mola, Lucrezia

    2016-05-01

    During the life cycle of fish the larval stages are the most interesting and variable. Teleost larvae undergo a daily increase in adaptability and many organs differentiate and become active. These processes are concerted and require an early neuro-immune-endocrine integration. In larvae communication among the nervous, endocrine and immune systems utilizes several known signal molecule families which could be different from those of the adult fish. The immune-neuroendocrine system was studied in several fish species, among which in particular the sea bass (Dicentrarchus labrax), that is a species of great commercial interest, very important in aquaculture and thus highly studied. Indeed the immune system of this species is the best known among marine teleosts. In this review the data on main signal molecules of stress carried out on larvae of fish are considered and discussed. For sea bass active roles in the early immunological responses of some well-known molecules involved in the stress, such as ACTH, nitric oxide, CRF, HSP-70 and cortisol have been proposed. These molecules and/or their receptors are biologically active mainly in the gut before complete differentiation of gut-associated lymphoid tissue (GALT), probably acting in an autocrine/paracrine way. An intriguing idea emerges from all results of these researches; the molecules involved in stress responses, expressed in the adult cells of the hypothalamic-pituitary axis, during the larval life of fish are present in several other localizations, where they perform probably the same role. It may be hypothesized that the functions performed by hypothalamic-pituitary system are particularly important for the survival of the larva and therefore they comprises several other localizations of body. Indeed the larval stages of fish are very crucial phases that include many physiological changes and several possible stress both internal and environmental. PMID:26968620

  9. Cannibalism stress response in Bacillus subtilis.

    Science.gov (United States)

    Höfler, Carolin; Heckmann, Judith; Fritsch, Anne; Popp, Philipp; Gebhard, Susanne; Fritz, Georg; Mascher, Thorsten

    2016-01-01

    When faced with carbon source limitation, the Gram-positive soil organism Bacillus subtilis initiates a survival strategy called sporulation, which leads to the formation of highly resistant endospores that allow B. subtilis to survive even long periods of starvation. In order to avoid commitment to this energy-demanding and irreversible process, B. subtilis employs another strategy called 'cannibalism' to delay sporulation as long as possible. Cannibalism involves the production and secretion of two cannibalism toxins, sporulation delaying protein (SDP) and sporulation killing factor (SKF), which are able to lyse sensitive siblings. The lysed cells are thought to then provide nutrients for the cannibals to slow down or even prevent them from entering sporulation. In this study, we uncovered the role of the cell envelope stress response (CESR), especially the Bce-like antimicrobial peptide detoxification modules, in the cannibalism stress response during the stationary phase. SDP and SKF specifically induce Bce-like systems and some extracytoplasmic function σ factors in stationary-phase cultures, but only the latter provide some degree of protection. A full Bce response is only triggered by mature toxins, and not by toxin precursors. Our study provides insights into the close relationship between stationary-phase survival and the CESR of B. subtilis. PMID:26364265

  10. [Metabolic response to trauma and stress].

    Science.gov (United States)

    Omerbegović, Meldijana; Durić, Amira; Muratović, Nusreta; Mulalić, Lejla; Hamzanija, Emina

    2003-01-01

    Trauma, surgery, burns and infection are accompanied with catabolic response which is characterized by enhanced protelysis, enhanced excretion of nitrogen, neoglucogenesis and resistance of peripheral tissues to insulin. This catabolic response is mediated through neural pathways and neuroendocrine axis. The purpose of this response is restoration of adequate perfusion and oxygenation and releasing of energy and substrates for the tissues, organs and systems which functions are essential for the survival. Metabolic response to injury and severe infection leads to decomposition of skeletal muscle proteins to amino acids, intensive liver gluconcogenesis from lactate, glycerol and alanin with enhanced oxidation of aminoacids. These substrates are necessary for synthesis of various mediators of protein or lipid nature, which are important for the defense and tissue regeneration. The changes result in negative balance of nitrogen, loss of body weight, and lower plasma concentration of all aminoacids. Patients who were unable to develop this hypercatabolic response have poor prognosis, and the patients with hypercatabolic response rapidly lose their body cell mass and without metabolic and nutritive support have more complications and higher mortality. Although neoglucogenesis, proteolysis and lipolysis are resistant to exogenous nutrients, metabolic support in critical illness improves the chances for survival until the healing of the disease. Casual therapy in such conditions is elimination of "stressors" which maintain abnormal endocrine and metabolic response. Adequate oxygenation, hemostasis, infection control and control of extracellular compartment expansion and low flows, are essential for the efficacy of nutritive support and that is the only way to convalescence and wound healing. PMID:15017867

  11. Tomato NAC transcription factor SlSRN1 positively regulates defense response against biotic stress but negatively regulates abiotic stress response.

    Directory of Open Access Journals (Sweden)

    Bo Liu

    Full Text Available Biotic and abiotic stresses are major unfavorable factors that affect crop productivity worldwide. NAC proteins comprise a large family of transcription factors that play important roles in plant growth and development as well as in responses to biotic and abiotic stresses. In a virus-induced gene silencing-based screening to identify genes that are involved in defense response against Botrytis cinerea, we identified a tomato NAC gene SlSRN1 (Solanum lycopersicum Stress-related NAC1. SlSRN1 is a plasma membrane-localized protein with transactivation activity in yeast. Expression of SlSRN1 was significantly induced by infection with B. cinerea or Pseudomonas syringae pv. tomato (Pst DC3000, leading to 6-8 folds higher than that in the mock-inoculated plants. Expression of SlSRN1 was also induced by salicylic acid, jasmonic acid and 1-amino cyclopropane-1-carboxylic acid and by drought stress. Silencing of SlSRN1 resulted in increased severity of diseases caused by B. cinerea and Pst DC3000. However, silencing of SlSRN1 resulted in increased tolerance against oxidative and drought stresses. Furthermore, silencing of SlSRN1 accelerated accumulation of reactive oxygen species but attenuated expression of defense genes after infection by B. cinerea. Our results demonstrate that SlSRN1 is a positive regulator of defense response against B. cinerea and Pst DC3000 but is a negative regulator for oxidative and drought stress response in tomato.

  12. Chronic intermittent psychological stress promotes macrophage reverse cholesterol transport by impairing bile acid absorption in mice.

    Science.gov (United States)

    Silvennoinen, Reija; Quesada, Helena; Kareinen, Ilona; Julve, Josep; Kaipiainen, Leena; Gylling, Helena; Blanco-Vaca, Francisco; Escola-Gil, Joan Carles; Kovanen, Petri T; Lee-Rueckert, Miriam

    2015-05-11

    Psychological stress is a risk factor for atherosclerosis, yet the pathophysiological mechanisms involved remain elusive. The transfer of cholesterol from macrophage foam cells to liver and feces (the macrophage-specific reverse cholesterol transport, m-RCT) is an important antiatherogenic pathway. Because exposure of mice to physical restraint, a model of psychological stress, increases serum levels of corticosterone, and as bile acid homeostasis is disrupted in glucocorticoid-treated animals, we investigated if chronic intermittent restraint stress would modify m-RCT by altering the enterohepatic circulation of bile acids. C57Bl/6J mice exposed to intermittent stress for 5 days exhibited increased transit through the large intestine and enhanced fecal bile acid excretion. Of the transcription factors and transporters that regulate bile acid homeostasis, the mRNA expression levels of the hepatic farnesoid X receptor (FXR), the bile salt export pump (BSEP), and the intestinal fibroblast growth factor 15 (FGF15) were reduced, whereas those of the ileal apical sodium-dependent bile acid transporter (ASBT), responsible for active bile acid absorption, remained unchanged. Neither did the hepatic expression of cholesterol 7α-hydroxylase (CYP7A1), the key enzyme regulating bile acid synthesis, change in the stressed mice. Evaluation of the functionality of the m-RCT pathway revealed increased fecal excretion of bile acids that had been synthesized from macrophage-derived cholesterol. Overall, our study reveals that chronic intermittent stress in mice accelerates m-RCT specifically by increasing fecal excretion of bile acids. This novel mechanism of m-RCT induction could have antiatherogenic potential under conditions of chronic stress. PMID:25969465

  13. Job stress factors, stress response, and social support in association with insomnia of Japanese male workers.

    Science.gov (United States)

    Nishitani, Naoko; Sakakibara, Hisataka

    2010-01-01

    The aim of the present study was to examine the relation of insomnia with job stress factors, stress response, and social support. A self-completed questionnaire survey was conducted in 212 male Japanese workers at a synthetic fiber plant. With regard to insomnia, subjects were asked the first 5 of the 8 questions on the Athens Insomnia Scale (AIS). Job stress factors, stress response and social support were assessed using the Job Stress Questionnaire. Multiple regression analyses showed that psychological job stress factors of poor appropriateness of work and high qualitative workload were associated with insomnia. The psychological stress response of depression and physical stress responses were also related with insomnia. Depression was also related to appropriateness of work. The present results showed that insomnia was closely related with the psychological job stress factor of appropriateness of work and the psychological response of depression. These mutual relationships between insomnia and poor mental health need be investigated further. PMID:20424348

  14. Avaliação de genótipos de aveia branca sob estresse de ácidos orgânicos Responses of white oat genotypes to stresses of organic acids

    Directory of Open Access Journals (Sweden)

    Mauricio Marini Kopp

    2009-01-01

    Full Text Available A ocorrência de condições anaeróbias nos solos hidromórficos, associada com a presença de matéria orgânica favorece o desenvolvimento de microrganismos anaeróbios que produzem substâncias fitotóxicas, principalmente ácidos orgânicos de cadeia curta. O objetivo do trabalho foi avaliar a resposta de 20 genótipos de aveia (Avena sativa L. aos ácidos acético, propiônico e butírico. O trabalho foi executado em sistema de hidroponia com três doses (0; 3 e 6 mM da mistura dos três ácidos na relação 6:3:1 respectivamente. O delineamento utilizado foi em blocos casualizados com três repetições em esquema fatorial. As variáveis mensuradas foram: comprimento de raízes (CR e parte aérea (CPA, número de raízes (NR e matéria seca de raízes (MSR e parte aérea (MSPA. Foram procedidas análise de variância e ajustes de regressão. Os efeitos de interação entre doses x genótipos para as variáveis CR e MSR revelaram significância e as regressões estabelecidas para estas variáveis, revelaram dois genótipos com estabilidade de crescimento radicular (OR-3 e FAPA-5 e três com estabilidade de acúmulo de matéria seca (OR-3, UFRGS-17 e UPF-15 frente ao estresse por ácidos orgânicos. A caracterização destes genótipos à ação fitotóxica dos ácidos orgânicos é importante fonte de recursos aos programas de melhoramento genético que visem obter genótipos com elevada capacidade produtiva, em solos de várzea do Sul do Brasil sob plantio direto ou cultivo mínimo.The association of anaerobic conditions with high organic matter content in hydromorphic soils favors the development of anaerobic microorganisms that produce phytotoxic substances, especially short chain organic acids. The objective of this investigation was to evaluate the response of 20 oat (Avena sativa L. genotypes to the exposure of acetic, propionic and butyric acids in hydroponic system. Three doses (0; 3 and 6 mM of a mixture of the three acids at a 6

  15. Hydration state controls stress responsiveness and social behavior

    OpenAIRE

    Krause, Eric G.; de Kloet, Annette D.; Flak, Jonathan N.; Smeltzer, Michael D.; Solomon, Matia B.; Evanson, Nathan K.; Woods, Stephen C; Sakai, Randall R.; Herman, James P.

    2011-01-01

    Life stress frequently occurs within the context of homeostatic challenge, requiring integration of physiological and psychological need into appropriate hormonal, cardiovascular and behavioral responses. To test neural mechanisms underlying stress integration within the context of homeostatic adversity, we evaluated the impact of a pronounced physiological (hypernatremia) challenge on hypothalamic-pituitary-adrenal (HPA), cardiovascular and behavioral responses to an acute psychogenic stress...

  16. Isolation of an osmotic stress- and abscisic acid-induced gene encoding an acidic endochitinase from Lycopersicon chilense.

    Science.gov (United States)

    Chen, R D; Yu, L X; Greer, A F; Cheriti, H; Tabaeizadeh, Z

    1994-10-28

    We have identified one osmotic stress- and abscisic acid-responsive member of the endochitinase (EC 3.2.1.14) gene family from leaves of drought-stressed Lycopersicon chilense plants, a natural inhabitant of extremely arid regions in South America. The 966-bp full-length cDNA (designated pcht28) encodes an acidic chitinase precursor with an amino-terminal signal peptide. The mature protein is predicted to have 229 amino acid residues with a relative molecular mass of 24,943 and pI value of 6.2. Sequence analysis revealed that pcht28 has a high degree of homology with class II chitinases (EC 3.2.1.14) from tomato and tobacco. Expression of the pcht28 protein in Escherichia coli verified that it is indeed a chitinase. Northern blot analysis indicated that this gene has evolved a different pattern of expression from that of other family members reported thus far. It is highly induced by both osmotic stress and the plant hormone abscisic acid. Southern blot analysis of genomic DNA suggested that the pcht28-related genes may form a small multigene family in this species. The efficiency of induction of the gene by drought stress, in leaves and stems, is significantly higher in L. chilense than in the cultivated tomato. It is speculated that, besides its general defensive function, the pcht28-encoded chitinase may play a particular role in plant development or in protecting plants from pathogen attack during water stress. PMID:7816027

  17. What is stress?: dose-response effects in commonly used in vitro stress assays

    OpenAIRE

    Claeys, Hannes; Van Landeghem, Sofie; Dubois, Marieke; Maleux, Katrien; Inzé, Dirk

    2014-01-01

    In vitro stress assays are commonly used to study the responses of plants to abiotic stress and to assess stress tolerance. A literature review reveals that most studies use very high stress levels and measure criteria such as germination, plant survival, or the development of visual symptoms such as bleaching. However, we show that these parameters are indicators of very severe stress, and such studies thus only provide incomplete information about stress sensitivity in Arabidopsis (Arabidop...

  18. Psychophysiological responses to stress after stress management training in patients with rheumatoid arthritis.

    OpenAIRE

    de Brouwer, Sabine J. M.; Kraaimaat, Floris W.; Sweep, Fred C. G. J.; Donders, Rogier T.; Agnes Eijsbouts; Saskia van Koulil; van Riel, Piet L C M; Evers, Andrea W. M.

    2011-01-01

    BACKGROUND: Stress management interventions may prove useful in preventing the detrimental effects of stress on health. This study assessed the effects of a stress management intervention on the psychophysiological response to stress in patients with rheumatoid arthritis (RA). METHODS: Seventy-four patients with RA, who were randomly assigned to either a control group or a group that received short-term stress management training, performed a standardized psychosocial stress task (Trier Socia...

  19. Cortical and subcortical gamma amino acid butyric acid deficits in anxiety and stress disorders: Clinical implications

    Science.gov (United States)

    Goddard, Andrew W

    2016-01-01

    Anxiety and stress disorders are a major public health issue. However, their pathophysiology is still unclear. The gamma amino acid butyric acid (GABA) neurochemical system has been strongly implicated in their pathogenesis and treatment by numerous preclinical and clinical studies, the most recent of which have been highlighted and critical review in this paper. Changes in cortical GABA appear related to normal personality styles and responses to stress. While there is accumulating animal and human neuroimaging evidence of cortical and subcortical GABA deficits across a number of anxiety conditions, a clear pattern of findings in specific brain regions for a given disorder is yet to emerge. Neuropsychiatric conditions with anxiety as a clinical feature may have GABA deficits as an underlying feature. Different classes of anxiolytic therapies support GABA function, and this may be an area in which newer GABA neuroimaging techniques could soon offer more personalized therapy. Novel GABAergic pharmacotherapies in development offer potential improvements over current therapies in reducing sedative and physiologic dependency effects, while offering rapid anxiolysis. PMID:27014597

  20. Citraturic response to oral citric acid load

    Science.gov (United States)

    Sakhaee, K.; Alpern, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    It is possible that some orally administered citrate may appear in urine by escaping oxidation in vivo. To determine whether this mechanism contributes to the citraturic response to potassium citrate, we measured serum and urinary citrate for 4 hours after a single oral load of citric acid (40 mEq.) in 6 normal subjects. Since citric acid does not alter acid-base balance, the effect of absorbed citrate could be isolated from that of alkali load. Serum citrate concentration increased significantly (p less than 0.05) 30 minutes after a single oral dose of citric acid and remained significantly elevated for 3 hours after citric acid load. Commensurate with this change, urinary citrate excretion peaked at 2 hours and gradually decreased during the next 2 hours after citric acid load. In contrast, serum and urinary citrate remained unaltered following the control load (no drug). Differences of the citratemic and citraturic effects between phases were significant (p less than 0.05) at 2 and 3 hours. Urinary pH, carbon dioxide pressure, bicarbonate, total carbon dioxide and ammonium did not change at any time after citric acid load, and did not differ between the 2 phases. No significant difference was noted in serum electrolytes, arterialized venous pH and carbon dioxide pressure at any time after citric acid load and between the 2 phases. Thus, the citraturic and citratemic effects of oral citric acid are largely accountable by provision of absorbed citrate, which has escaped in vivo degradation.

  1. Physiological and molecular responses to drought in Petunia: the importance of stress severity

    OpenAIRE

    Kim, Jongyun; Malladi, Anish; van Iersel, Marc W.

    2012-01-01

    Plant responses to drought stress vary depending on the severity of stress and the stage of drought progression. To improve the understanding of such responses, the leaf physiology, abscisic acid (ABA) concentration, and expression of genes associated with ABA metabolism and signalling were investigated in Petunia × hybrida. Plants were exposed to different specific substrate water contents (θ = 0.10, 0.20, 0.30, or 0.40 m3·m–3) to induce varying levels of drought stress. Plant responses were...

  2. Understanding the responses of rice to environmental stress using proteomics.

    Science.gov (United States)

    Singh, Raksha; Jwa, Nam-Soo

    2013-11-01

    Diverse abiotic and biotic stresses have marked effects on plant growth and productivity. To combat such stresses, plants have evolved complex but not well understood responses. Common effects upon perception of environmental stress are differential expression of the plant proteome and the synthesis of novel regulatory proteins for protection from and acclimation to stress conditions. Plants respond differently in terms of activation of stress-responsive signaling pathways depending upon the type and nature of the stresses to which they are exposed. Progress in proteomics and systems biology approaches has made it possible to identify the novel proteins and their interactions that function in abiotic stress responses. This will enable elucidation of the functions of individual proteins and their roles in signaling networks. Proteomic analysis of the responses to various stress conditions is performed most commonly using 2D gel electrophoresis and high-throughput identification by LC-MS/MS. Because of recent developments in proteomics techniques, numerous proteomics studies of rice under abiotic stress conditions have been performed. In this review, proteomics studies addressing rice responses to the major environmental stresses--including cold, heat, drought, salt, heavy metals, minerals, UV radiation, and ozone--are discussed. Unique or common protein responses to these stress conditions are summarized and interpreted according to their possible physiological responses in each stress. Additionally, proteomics studies on various plant systems under various abiotic stress conditions are compared to provide deeper understanding of specific and common proteome responses in rice and other plant systems, which will further contribute to the identification of abiotic stress tolerance factor at protein level. Functional analysis of stress-responsive proteins will provide new research objectives with the aim of achieving stable crop productivity in the face of the

  3. Weak organic acid stress in Bacillus subtilis

    NARCIS (Netherlands)

    A.S. ter Beek

    2009-01-01

    Weak organic acids are commonly used food preservatives that protect food products from bacterial contamination. A variety of spore-forming bacterial species pose a serious problem to the food industry by causing extensive food spoilage or even food poisoning. Understanding the mechanisms of bacteri

  4. Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens

    2007-01-01

    Lack of post-sampling stability of ascorbate and dehydroascorbic acid and failure to block their in vivo equilibrium have lowered their value as biomarkers of oxidative stress and limited the ability to further investigate their possible role in disease prevention. In the present paper......, the analytical reproducibility was tested by repeated analysis of plasma aliquots from one individual over four years. The plasma was subjected to acidic deproteinization with an equal volume of 10% meta-phosphoric acid containing 2 mM EDTA and analyzed for ascorbate and dehydroascorbic acid by high...

  5. The Plant Heat Stress Transcription Factors (HSFs): Structure, Regulation, and Function in Response to Abiotic Stresses.

    Science.gov (United States)

    Guo, Meng; Liu, Jin-Hong; Ma, Xiao; Luo, De-Xu; Gong, Zhen-Hui; Lu, Ming-Hui

    2016-01-01

    Abiotic stresses such as high temperature, salinity, and drought adversely affect the survival, growth, and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological, and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs), including heat stress transcription factors (HSFs). HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps). In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  6. The plant heat stress transcription factors (HSFs: structure, regulation and function in response to abiotic stresses

    Directory of Open Access Journals (Sweden)

    Meng eGuo

    2016-02-01

    Full Text Available Abiotic stresses such as high temperature, salinity and drought adversely affect the survival, growth and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs, including heat stress transcription factors (HSFs. HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps. In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  7. Epigenetic regulation of stress responses in plants

    OpenAIRE

    Chinnusamy, Viswanathan; Zhu, Jian-Kang

    2009-01-01

    Gene expression driven by developmental and stress cues often depends on nucleosome histone post-translational modifications and sometimes on DNA methylation. A number of studies have shown that these DNA and histone modifications play a key role in gene expression and plant development under stress. Most of these stress-induced modifications are reset to the basal level once the stress is relieved, while some of the modifications may be stable, that is, may be carried forward as ‘stress memo...

  8. Biotechnological Approaches to Study Plant Responses to Stress

    OpenAIRE

    Pérez-Clemente, Rosa M; Vicente Vives; Zandalinas, Sara I.; López-Climent, María F.; Valeria Muñoz; Aurelio Gómez-Cadenas

    2013-01-01

    Multiple biotic and abiotic environmental stress factors affect negatively various aspects of plant growth, development, and crop productivity. Plants, as sessile organisms, have developed, in the course of their evolution, efficient strategies of response to avoid, tolerate, or adapt to different types of stress situations. The diverse stress factors that plants have to face often activate similar cell signaling pathways and cellular responses, such as the production of stress proteins, upre...

  9. Biological stress response terminology: Integrating the concepts of adaptive response and preconditioning stress within a hormetic dose-response framework.

    Science.gov (United States)

    Calabrese, Edward J; Bachmann, Kenneth A; Bailer, A John; Bolger, P Michael; Borak, Jonathan; Cai, Lu; Cedergreen, Nina; Cherian, M George; Chiueh, Chuang C; Clarkson, Thomas W; Cook, Ralph R; Diamond, David M; Doolittle, David J; Dorato, Michael A; Duke, Stephen O; Feinendegen, Ludwig; Gardner, Donald E; Hart, Ronald W; Hastings, Kenneth L; Hayes, A Wallace; Hoffmann, George R; Ives, John A; Jaworowski, Zbigniew; Johnson, Thomas E; Jonas, Wayne B; Kaminski, Norbert E; Keller, John G; Klaunig, James E; Knudsen, Thomas B; Kozumbo, Walter J; Lettieri, Teresa; Liu, Shu-Zheng; Maisseu, Andre; Maynard, Kenneth I; Masoro, Edward J; McClellan, Roger O; Mehendale, Harihara M; Mothersill, Carmel; Newlin, David B; Nigg, Herbert N; Oehme, Frederick W; Phalen, Robert F; Philbert, Martin A; Rattan, Suresh I S; Riviere, Jim E; Rodricks, Joseph; Sapolsky, Robert M; Scott, Bobby R; Seymour, Colin; Sinclair, David A; Smith-Sonneborn, Joan; Snow, Elizabeth T; Spear, Linda; Stevenson, Donald E; Thomas, Yolene; Tubiana, Maurice; Williams, Gary M; Mattson, Mark P

    2007-07-01

    Many biological subdisciplines that regularly assess dose-response relationships have identified an evolutionarily conserved process in which a low dose of a stressful stimulus activates an adaptive response that increases the resistance of the cell or organism to a moderate to severe level of stress. Due to a lack of frequent interaction among scientists in these many areas, there has emerged a broad range of terms that describe such dose-response relationships. This situation has become problematic because the different terms describe a family of similar biological responses (e.g., adaptive response, preconditioning, hormesis), adversely affecting interdisciplinary communication, and possibly even obscuring generalizable features and central biological concepts. With support from scientists in a broad range of disciplines, this article offers a set of recommendations we believe can achieve greater conceptual harmony in dose-response terminology, as well as better understanding and communication across the broad spectrum of biological disciplines.

  10. Overexpression of a cytosolic abiotic stress responsive universal stress protein (SbUSP mitigates salt and osmotic stress in transgenic tobacco plants

    Directory of Open Access Journals (Sweden)

    Pushpika eUdawat

    2016-04-01

    Full Text Available The Universal Stress Protein (USP is a ubiquitous protein and plays an indispensable role in plant abiotic stress tolerance. The genome of Salicornia brachiata contains two homologues of intron less SbUSP gene which encodes for salt and osmotic responsive universal stress protein. In vivo localization reveals that SbUSP is a membrane bound cytosolic protein. The role of the gene was functionally validated by developing transgenic tobacco and compared with control (wild type and vector control plants under different abiotic stress condition. Transgenic lines (T1 exhibited higher chlorophyll, relative water, proline, total sugar, reducing sugar, free amino acids, polyphenol contents, osmotic potential, membrane stability and lower electrolyte leakage and lipid peroxidation (malondialdehyde content under stress treatments than control (WT and VC plants. Lower accumulation of H2O2 and O2- radicals was also detected in transgenic lines compared to control plants under stress conditions. Present study confers that overexpression of the SbUSP gene enhances plant growth, alleviates ROS buildup, maintains ion homeostasis and improves the physiological status of the plant under salt and osmotic stresses. Principal component analysis (PCA exhibited a statistical distinction of plant response to salinity stress, and a significant response was observed for transgenic lines under stress, which provides stress endurance to the plant. A possible signaling role is proposed that some downstream genes may get activated by abiotic stress responsive cytosolic SbUSP, which leads to the protection of cell from oxidative damages. The study unveils that ectopic expression of the gene mitigates salt or osmotic stress by scavenging ROS and modulating the physiological process of the plant.

  11. Salicylic acid alleviates cold-induced photosynthesis inhibition and oxidative stress in Jasminum sambac

    OpenAIRE

    CAI, HAN; He, Mengying; Ma, Kun; HUANG, YONGGAO; Wang, Yun

    2015-01-01

    Salicylic acid (SA) is a signal molecule that mediates many biotic and abiotic stress-induced physiological responses in plants. In the current study the protective effects of SA on cold stress-caused oxidative damage and photosynthesis inhibition in jasmine plants (Jasminum sambac) were examined. Jasmine seedlings were pretreated with 100 µM SA for 3 days and then subjected to cold stress (4 °C) for 15 days. The amounts of superoxide radicals (O_2^{-}) and hydrogen peroxide (H_{2}O_{2}) sign...

  12. Effects of Exogenous Abscisic Acid and Water Stress on the Growth Response of Subterranean Clover of Different Genotypes%外源ABA和水分胁迫对不同基因型三叶草生长的影响

    Institute of Scientific and Technical Information of China (English)

    许兴; 郑国琦; 邓西平

    2002-01-01

    The response of subterranean clover (Trifolium subterraneum L.) to different abscisic acid (ABA) concentrations (10-6, 10-5, 10-4 mol/L) in nutrient solution and to water stress were studied in growth room. Six cultivars of contrasting yield capacity were compared. Plants remained growing in Hoagland solution or pots until at least four full-developed leaves appeared. The ABA was then applied and the fresh weight, leaf number and length of the largest root were measured at 1, 4, 7 and 11 d after ABA treatment. The above parameters were also measured at 15 d under water stress. In all the tested genotypes ABA caused similar reduction in these growth parameters, as well as a significant decrease of leaf water potential which was dependent on ABA concentration. The average growth reduction after 11 d under 10-4 mol/L ABA coincided with the range of these crops under water stress in pot experiments. On average of the different genotypes, leaf number, area of full-developed leaf and the dry weight per plant decreased by about 50% whereas the root/shoot ratio increased by 80%.The genotype variation and ranking for this treatment were rather similar to the same genotypes in pot experiments. The genotypes, Clare, Nuba and Seaton Park, showed the best results under both control and ABA treated conditions and water stress conditions. The similarity between the response to ABA in nutrient solution and to water stress opens the possibility to use this approach as a way to quantify the drought resistance of subterranean clover genotypes.%在室内研究了不同浓度外源ABA处理和不同水分胁迫对6种不同基因型的三叶草(Trifolium subterraneum L.)生长的影响.当三叶草的第四片叶完全展开时,向营养液中施加不同浓度的ABA时对盆栽土壤进行控水.在处理的1,4,7和11 d,测定植株鲜重、叶片数、最长根长,以表示三叶草的生长状况.各参试品种以上三项生长指标均受外源ABA和水分胁迫的影响而呈

  13. Regulation of oxidative stress response by CosR, an essential response regulator in Campylobacter jejuni.

    Directory of Open Access Journals (Sweden)

    Sunyoung Hwang

    Full Text Available CosR (Campylobacter oxidative stress regulator; Cj0355c is an OmpR-type response regulator essential for the viability of Campylobacter jejuni, a leading foodborne pathogen causing human gastroenteritis worldwide. Despite importance, the function of CosR remains completely unknown mainly because of cell death caused by its knockout mutation. To overcome this technical limitation, in this study, antisense technology was used to investigate the regulatory function of CosR by modulating the level of CosR expression. Two-dimensional gel electrophoresis (2DGE was performed to identify the CosR regulon either by suppressing CosR expression with antisense peptide nucleic acid (PNA or by overexpressing CosR in C. jejuni. According to the results of 2DGE, CosR regulated 32 proteins involved in various cellular processes. Notably, CosR negatively regulated a few key proteins of the oxidative stress response of C. jejuni, such as SodB, Dps, Rrc and LuxS, whereas CosR positively controlled AhpC. Electrophoretic mobility shift assay showed that CosR directly bound to the promoter region of the oxidative stress genes. DNase I footprinting assays identified 21-bp CosR binding sequences in the sodB and ahpC promoters, suggesting CosR specifically recognizes and binds to the regulated genes. Interestingly, the level of CosR protein was significantly reduced by paraquat (a superoxide generator but not by hydrogen peroxide. Consistent with the overall negative regulation of oxidative stress defense proteins by CosR, the CosR knockdown by antisense rendered C. jejuni more resistant to oxidative stress compared to the wild type. Overall, this study reveals the important role played by the essential response regulator CosR in the oxidative stress defense of C. jejuni.

  14. Neurovascular responses to mental stress in prehypertensive humans

    OpenAIRE

    Schwartz, Christopher E.; Durocher, John J.; Carter, Jason R.

    2010-01-01

    Neurovascular responses to mental stress have been linked to several cardiovascular diseases, including hypertension. Mean arterial pressure (MAP), muscle sympathetic nerve activity (MSNA), and forearm vascular responses to mental stress are well documented in normotensive (NT) subjects, but responses in prehypertensive (PHT) subjects remain unclear. We tested the hypothesis that PHT would elicit a more dramatic increase of MAP during mental stress via augmented MSNA and blunted forearm vascu...

  15. Plasma transcortin influences endocrine and behavioral stress responses in mice

    OpenAIRE

    Richard, Elodie M.; Helbling, Jean-Christophe; Tridon, Claudine; Desmedt, Aline; Minni, Amandine; Cador, Martine; Pourtau, Line; Konsman, Jan Peter; Mormède, Pierre; Moisan, Marie-Pierre

    2010-01-01

    Glucocorticoids are released after hypothalamus-pituitary-adrenal axis stimulation by stress and act both in the periphery and in the brain to bring about adaptive responses that are essential for life. Dysregulation of the stress response can precipitate psychiatric diseases, in particular depression. Recent genetic studies have suggested that the glucocorticoid carrier transcortin, also called corticosteroid-binding globulin (CBG), may have an important role in stress response. We have inve...

  16. Protective effects of gallic acid against spinal cord injury-induced oxidative stress.

    Science.gov (United States)

    Yang, Yong Hong; Wang, Zao; Zheng, Jie; Wang, Ran

    2015-08-01

    The present study aimed to investigate the role of gallic acid in oxidative stress induced during spinal cord injury (SCI). In order to measure oxidative stress, the levels of lipid peroxide, protein carbonyl, reactive oxygen species and nitrates/nitrites were determined. In addition, the antioxidant status during SCI injury and the protective role of gallic acid were investigated by determining glutathione levels as well as the activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione-S-transferase. Adenosine triphophatase (ATPase) enzyme activities were determined to evaluate the role of gallic acid in SCI-induced deregulation of the activity of enzymes involved in ion homeostasis. The levels of inflammatory markers such as nuclear factor (NF)-κB and cycloxygenase (COX)-2 were determined by western blot analysis. Treatment with gallic acid was observed to significantly mitigate SCI-induced oxidative stress and the inflammatory response by reducing the oxidative stress, decreasing the expression of NF-κB and COX-2 as well as increasing the antioxidant status of cells. In addition, gallic acid modulated the activity of ATPase enzymes. Thus the present study indicated that gallic acid may have a role as a potent antioxidant and anti-inflammatory agent against SCI. PMID:25955644

  17. Identification of Arabidopsis candidate genes in response to biotic and abiotic stresses using comparative microarrays.

    Directory of Open Access Journals (Sweden)

    Arjun Sham

    Full Text Available Plants have evolved with intricate mechanisms to cope with multiple environmental stresses. To adapt with biotic and abiotic stresses, plant responses involve changes at the cellular and molecular levels. The current study was designed to investigate the effects of combinations of different environmental stresses on the transcriptome level of Arabidopsis genome using public microarray databases. We investigated the role of cyclopentenones in mediating plant responses to environmental stress through TGA (TGACG motif-binding factor transcription factor, independently from jasmonic acid. Candidate genes were identified by comparing plants inoculated with Botrytis cinerea or treated with heat, salt or osmotic stress with non-inoculated or non-treated tissues. About 2.5% heat-, 19% salinity- and 41% osmotic stress-induced genes were commonly upregulated by B. cinerea-treatment; and 7.6%, 19% and 48% of genes were commonly downregulated by B. cinerea-treatment, respectively. Our results indicate that plant responses to biotic and abiotic stresses are mediated by several common regulatory genes. Comparisons between transcriptome data from Arabidopsis stressed-plants support our hypothesis that some molecular and biological processes involved in biotic and abiotic stress response are conserved. Thirteen of the common regulated genes to abiotic and biotic stresses were studied in detail to determine their role in plant resistance to B. cinerea. Moreover, a T-DNA insertion mutant of the Responsive to Dehydration gene (rd20, encoding for a member of the caleosin (lipid surface protein family, showed an enhanced sensitivity to B. cinerea infection and drought. Overall, the overlapping of plant responses to abiotic and biotic stresses, coupled with the sensitivity of the rd20 mutant, may provide new interesting programs for increased plant resistance to multiple environmental stresses, and ultimately increases its chances to survive. Future research

  18. Origins of asymmetric stress-strain response in phase transformations

    Energy Technology Data Exchange (ETDEWEB)

    Sehitoglu, H.; Gall, K. [Univ. of Illinois, Urbana, IL (United States)

    1997-12-31

    It has been determined that the transformation stress-strain behavior of CuZnAl and NiTi shape memory alloys is dependent on the applied stress state. The uniaxial compressive stress necessary to macroscopically trigger the transformation is approximately 34% (CuZnAl) and 26% (NiTi) larger than the required uniaxial tensile stress. For three dimensional stress states, the response of either alloy system is dependent on the directions of the dominant principal stresses along with the hydrostatic stress component of the stress state. The stress state effects are dominated by the favored growth and nucleation of more martensite plates in tension versus compression. The effect of different hydrostatic pressure levels between stress states on martensite plates volume change is considered small.

  19. Exogenous Application of Citric Acid Ameliorates the Adverse Effect of Heat Stress in Tall Fescue (Lolium arundinaceum).

    Science.gov (United States)

    Hu, Longxing; Zhang, Zhifei; Xiang, Zuoxiang; Yang, Zhijian

    2016-01-01

    Citric acid may be involved in plant response to high temperature. The objective of this study was to investigate whether exogenous citric acid could improve heat tolerance in a cool-season turfgrass species, tall fescue (Lolium arundinaceum), and to determine the physiological mechanisms of citric acid effects on heat stress tolerance. The grasses were subjected to four citric acid levels (0, 0.2, 2, and 20 mM) and two temperature levels (25/20 and 35/30 ± 0.5°C, day/night) treatments in growth chambers. Heat stress increased an electrolyte leakage (EL) and malonaldehyde (MDA) content, while reduced plant growth, chlorophyll (Chl) content, photochemical efficiency (Fv/Fm), root activity and antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD). External citric acid alleviated the detrimental effects of heat stress on tall fescue, which was evidenced by decreased EL and MDA content, and improved plant growth under stress conditions. Additionally, the reduction in Chl content, Fv/Fm, SOD, POD, CAT and root activity were ameliorated in citric acid treated plants under heat stressed conditions. High temperature induced the expression of heat shock protein (HSP) genes, which exhibited greater expression levels after citric acid treatment under heat stress. These results suggest that exogenous citric acid application may alleviate growth and physiological damage caused by high temperature. In addition, the exogenously applied citric acid might be responsible for maintaining membrane stability, root activity, and activation of antioxidant response and HSP genes which could contribute to the protective roles of citric acid in tall fescue responses to heat stress.

  20. Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism.

    Science.gov (United States)

    Kissoudis, Christos; Sunarti, Sri; van de Wiel, Clemens; Visser, Richard G F; van der Linden, C Gerard; Bai, Yuling

    2016-09-01

    Stress conditions in agricultural ecosystems can occur at variable intensities. Different resistance mechanisms against abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of different levels of salt stress ranging from mild to severe (50, 100, and 150mM NaCl) on powdery mildew resistance and overall performance of tomato introgression lines with contrasting levels of partial resistance, as well as near-isogenic lines (NILs) carrying the resistance gene Ol-1 (associated with a slow hypersensitivity response; HR), ol-2 (an mlo mutant associated with papilla formation), and Ol-4 (an R gene associated with a fast HR). Powdery mildew resistance was affected by salt stress in a genotype- and stress intensity-dependent manner. In susceptible and partial resistant lines, increased susceptibility was observed under mild salt stress (50mM) which was accompanied by accelerated cell death-like senescence. In contrast, severe salt stress (150mM) reduced disease symptoms. Na(+) and Cl(-) accumulation in the leaves was linearly related to the decreased pathogen symptoms under severe stress. In contrast, complete resistance mediated by ol-2 and Ol-4 was unaffected under all treatment combinations, and was associated with a decreased growth penalty. Increased susceptibility and senescence under combined stress in NIL-Ol-1 was associated with the induction of ethylene and jasmonic acid pathway genes and the cell wall invertase gene LIN6. These results highlight the significance of stress severity and resistance type on the plant's performance under the combination of abiotic and biotic stress.

  1. Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism.

    Science.gov (United States)

    Kissoudis, Christos; Sunarti, Sri; van de Wiel, Clemens; Visser, Richard G F; van der Linden, C Gerard; Bai, Yuling

    2016-09-01

    Stress conditions in agricultural ecosystems can occur at variable intensities. Different resistance mechanisms against abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of different levels of salt stress ranging from mild to severe (50, 100, and 150mM NaCl) on powdery mildew resistance and overall performance of tomato introgression lines with contrasting levels of partial resistance, as well as near-isogenic lines (NILs) carrying the resistance gene Ol-1 (associated with a slow hypersensitivity response; HR), ol-2 (an mlo mutant associated with papilla formation), and Ol-4 (an R gene associated with a fast HR). Powdery mildew resistance was affected by salt stress in a genotype- and stress intensity-dependent manner. In susceptible and partial resistant lines, increased susceptibility was observed under mild salt stress (50mM) which was accompanied by accelerated cell death-like senescence. In contrast, severe salt stress (150mM) reduced disease symptoms. Na(+) and Cl(-) accumulation in the leaves was linearly related to the decreased pathogen symptoms under severe stress. In contrast, complete resistance mediated by ol-2 and Ol-4 was unaffected under all treatment combinations, and was associated with a decreased growth penalty. Increased susceptibility and senescence under combined stress in NIL-Ol-1 was associated with the induction of ethylene and jasmonic acid pathway genes and the cell wall invertase gene LIN6. These results highlight the significance of stress severity and resistance type on the plant's performance under the combination of abiotic and biotic stress. PMID:27436279

  2. Adulthood stress responses in rats are variably altered as a factor of adolescent stress exposure.

    Science.gov (United States)

    Moore, Nicole L T; Altman, Daniel E; Gauchan, Sangeeta; Genovese, Raymond F

    2016-05-01

    Stress exposure during development may influence adulthood stress response severity. The present study investigates persisting effects of two adolescent stressors upon adulthood response to predator exposure (PE). Rats were exposed to underwater trauma (UWT) or PE during adolescence, then to PE after reaching adulthood. Rats were then exposed to predator odor (PO) to test responses to predator cues alone. Behavioral and neuroendocrine assessments were conducted to determine acute effects of each stress experience. Adolescent stress altered behavioral response to adulthood PE. Acoustic startle response was blunted. Bidirectional changes in plus maze exploration were revealed as a factor of adolescent stress type. Neuroendocrine response magnitude did not predict severity of adolescent or adult stress response, suggesting that different adolescent stress events may differentially alter developmental outcomes regardless of acute behavioral or neuroendocrine response. We report that exposure to two different stressors in adolescence may differentially affect stress response outcomes in adulthood. Acute response to an adolescent stressor may not be consistent across all stressors or all dependent measures, and may not predict alterations in developmental outcomes pertaining to adulthood stress exposure. Further studies are needed to characterize factors underlying long-term effects of a developmental stressor.

  3. A central role of abscisic acid in stress-regulated carbohydrate metabolism.

    Directory of Open Access Journals (Sweden)

    Stefan Kempa

    Full Text Available BACKGROUND: Abiotic stresses adversely affect plant growth and development. The hormone abscisic acid (ABA plays a central role in the response and adaptation to environmental constraints. However, apart from the well established role of ABA in regulating gene expression programmes, little is known about its function in plant stress metabolism. PRINCIPAL FINDINGS: Using an integrative multiparallel approach of metabolome and transcriptome analyses, we studied the dynamic response of the model glyophyte Arabidopsis thaliana to ABA and high salt conditions. Our work shows that salt stress induces complex re-adjustment of carbohydrate metabolism and that ABA triggers the initial steps of carbon mobilisation. SIGNIFICANCE: These findings open new perspectives on how high salinity and ABA impact on central carbohydrate metabolism and highlight the power of iterative combinatorial approaches of non-targeted and hypothesis-driven experiments in stress biology.

  4. Role of Abscisic Acid and Water Stress on the Activities of Antioxidant Enzymes in Wheat

    Directory of Open Access Journals (Sweden)

    Hadeesa Naz

    2014-07-01

    Full Text Available Eight wheat varieties (Chinese Spring, Pavon, Gabo, Saleem-2000, Zamindar-04, Siren, NR-264 and Marvi were compared for their response to exogenous application of abscisic acid (ABA, Water Stress (WS and Control (C during invitro condition. Their responses were studied in the form of seedlings growth and antioxidant enzymes. Exogenous application of ABA reflected ameliorating effect on catalase activity. Water stress treatment led to increase in levels of catalase except Pavon. Increased activity of antioxidant enzymes showed tolerance capacity under water stress. Correlation coefficient analysis reflected negative and significant relationship between total protein contents and peroxidase and catalase. Further, investigations are needed to enhance the understanding on the effect of different abiotic stresses and growth hormones during early seed development.

  5. Immune responses to stress in rheumatoid arthritis and psoriasis

    NARCIS (Netherlands)

    Brouwer, S.J. dr; Middendorp, H. van; Stormink, C.; Kraaimaat, F.W.; Joosten, I.; Radstake, T.R.; Jong, E.M. de; Schalkwijk, J.; Donders, A.R.; Eijsbouts, A.M.M.; Kerkhof, P.C.M. van de; Riel, P.L.C.M. van; Evers, A.W.

    2014-01-01

    OBJECTIVE: Stress is one of the factors that may exacerbate the progression of chronic inflammatory diseases such as RA and psoriasis. We exploratively compared the effects of acute stress on levels of circulating cytokines involved in disease progression and/or the stress response in patients with

  6. The Stress Response Regulator AflSkn7 Influences Morphological Development, Stress Response, and Pathogenicity in the Fungus Aspergillus flavus

    Science.gov (United States)

    Zhang, Feng; Xu, Gaopo; Geng, Longpo; Lu, Xiaoyan; Yang, Kunlong; Yuan, Jun; Nie, Xinyi; Zhuang, Zhenhong; Wang, Shihua

    2016-01-01

    This study focused on AflSkn7, which is a stress response regulator in the aflatoxin-producing Aspergillus flavus. The ΔAflSkn7 mutants exhibited partially defective conidial formation and a complete inability to generate sclerotia, indicating AflSkn7 affects A. flavus asexual and sexual development. The mutants tolerated osmotic stress but were partially susceptible to the effects of cell wall stress. Additionally, the ΔAflSkn7 mutants were especially sensitive to oxidative stress. These observations confirmed that AflSkn7 influences oxidative stress responses rather than osmotic stress responses. Additionally, AflSkn7 was observed to increase aflatoxin biosynthesis and seed infection rates. These results indicate AflSkn7 affects A. flavus morphological development, stress response, aflatoxin production, and pathogenicity. The results of this study may facilitate the development of new methods to manage A. flavus infections. PMID:27399770

  7. Detection of Acid Rain Stress Effect on Plant Using Hyperspectral Data in Three Gorges Region,China

    Institute of Scientific and Technical Information of China (English)

    SONG Xiaodong; JIANG Hong; YU Shuquan; ZHOU Guomo

    2008-01-01

    This paper aims to use hyperspectral data to detect the spectral change caused by acid stress to a native forest type in the Three Gorges region of China.For this purpose,a ground-based hyperspectral experiment was conducted at the Three Gorges region to detect acid deposition that caused Masson pine (Pinus massoniana) forest degradation.Continuum removal method was used to isolate wavebands more responsive to stress in wavelengths 450-750nm.The differences in chlorophyll concentrations and needle thickness caused by acidic stress are found to be explicable to the different spectral reflectance patterns in the visible and near-infrared wavelengths.Two new chlorotic indices were utilized to explain the stress-caused leaf chiorosis.The comparison of simulated vegetation indices and principal component analysis (PCA) results suggests that it would be possible to monitor acid rain stress effect on forest ecosystem from some wider spectral regions.

  8. Cellular stress responses for monitoring and modulating ageing

    DEFF Research Database (Denmark)

    Demirovic, Dino; Schnebert, Sylvianne; Nizard, Carine;

    2013-01-01

    protectors and stimulators of homeodynamics, and create a kind of “gold-standard” for monitoring the efficacy of other potential antiageing and pro-survival natural and synthetic compounds. We have so far standardised an effective method for detecting all seven stress response pathways, by several......Cellular stress response is a crucial factor in maintaining efficient homeodynamics for survival, health and longevity. Both the immediate and delayed responses to external and internal stressors effectively determine the molecular biochemical and physiological stability in a dynamic...... and interactive manner. There are three main aspects of stress responses: (i) immediate stress response involving extra- and intra-cellular signaling during the period of disturbance and exposure to the stressors; (ii) delayed stress response involving sensors and modulators in the presence of stressors or after...

  9. Regulation of Stress Responses and Translational Control by Coronavirus

    Science.gov (United States)

    Fung, To Sing; Liao, Ying; Liu, Ding Xiang

    2016-01-01

    Similar to other viruses, coronavirus infection triggers cellular stress responses in infected host cells. The close association of coronavirus replication with the endoplasmic reticulum (ER) results in the ER stress responses, which impose a challenge to the viruses. Viruses, in turn, have come up with various mechanisms to block or subvert these responses. One of the ER stress responses is inhibition of the global protein synthesis to reduce the amount of unfolded proteins inside the ER lumen. Viruses have evolved the capacity to overcome the protein translation shutoff to ensure viral protein production. Here, we review the strategies exploited by coronavirus to modulate cellular stress response pathways. The involvement of coronavirus-induced stress responses and translational control in viral pathogenesis will also be briefly discussed. PMID:27384577

  10. Regulation of Stress Responses and Translational Control by Coronavirus

    Directory of Open Access Journals (Sweden)

    To Sing Fung

    2016-07-01

    Full Text Available Similar to other viruses, coronavirus infection triggers cellular stress responses in infected host cells. The close association of coronavirus replication with the endoplasmic reticulum (ER results in the ER stress responses, which impose a challenge to the viruses. Viruses, in turn, have come up with various mechanisms to block or subvert these responses. One of the ER stress responses is inhibition of the global protein synthesis to reduce the amount of unfolded proteins inside the ER lumen. Viruses have evolved the capacity to overcome the protein translation shutoff to ensure viral protein production. Here, we review the strategies exploited by coronavirus to modulate cellular stress response pathways. The involvement of coronavirus-induced stress responses and translational control in viral pathogenesis will also be briefly discussed.

  11. Relation between stress-precipitated seizures and the stress response in childhood epilepsy.

    Science.gov (United States)

    van Campen, Jolien S; Jansen, Floor E; Pet, Milou A; Otte, Willem M; Hillegers, Manon H J; Joels, Marian; Braun, Kees P J

    2015-08-01

    The majority of patients with epilepsy report that seizures are sometimes triggered or provoked. Stress is the most frequently self-reported seizure-precipitant. The mechanisms underlying stress-sensitivity of seizures are currently unresolved. We hypothesized that stress-sensitivity of seizures relates to alteration of the stress response, which could affect neuronal excitability and hence trigger seizures. To study this, children with epilepsy between 6 and 17 years of age and healthy controls, with similar age, sex and intelligence, were exposed to a standardized acute psychosocial stressor (the Trier Social Stress Test for Children), during which salivary cortisol and sympathetic parameters were measured. Beforehand, the relation between stress and seizures in children with epilepsy was assessed by (i) a retrospective questionnaire; and (ii) a prospective 6-week diary on stress and seizure occurrence. Sixty-four children with epilepsy and 40 control subjects were included in the study. Of all children with epilepsy, 49% reported that seizures were precipitated by acute stress. Diary analysis showed a positive association between acute stress and seizures in 62% of children who experienced at least one seizure during the diary period. The acute social stress test was completed by 56 children with epilepsy and 37 control subjects. Children with sensitivity of seizures for acute stress, either determined by the questionnaire or by the prospective diary, showed a blunted cortisol response to stress compared with patients without acute stress-precipitated seizures and healthy controls (questionnaire-based F = 2.74, P = 0.018; diary-based F = 4.40, P = 0.007). No baseline differences in cortisol were observed, nor differences in sympathetic stress response. The relation between acute stress-sensitivity of seizures and the cortisol response to stress remained significant in multivariable analysis (β = -0.30, P = 0.03). Other variables associated with the acute stress

  12. Increasing fatty acid oxidation remodels the hypothalamic neurometabolome to mitigate stress and inflammation.

    Directory of Open Access Journals (Sweden)

    Joseph W McFadden

    Full Text Available Modification of hypothalamic fatty acid (FA metabolism can improve energy homeostasis and prevent hyperphagia and excessive weight gain in diet-induced obesity (DIO from a diet high in saturated fatty acids. We have shown previously that C75, a stimulator of carnitine palmitoyl transferase-1 (CPT-1 and fatty acid oxidation (FAOx, exerts at least some of its hypophagic effects via neuronal mechanisms in the hypothalamus. In the present work, we characterized the effects of C75 and another anorexigenic compound, the glycerol-3-phosphate acyltransferase (GPAT inhibitor FSG67, on FA metabolism, metabolomics profiles, and metabolic stress responses in cultured hypothalamic neurons and hypothalamic neuronal cell lines during lipid excess with palmitate. Both compounds enhanced palmitate oxidation, increased ATP, and inactivated AMP-activated protein kinase (AMPK in hypothalamic neurons in vitro. Lipidomics and untargeted metabolomics revealed that enhanced catabolism of FA decreased palmitate availability and prevented the production of fatty acylglycerols, ceramides, and cholesterol esters, lipids that are associated with lipotoxicity-provoked metabolic stress. This improved metabolic signature was accompanied by increased levels of reactive oxygen species (ROS, and yet favorable changes in oxidative stress, overt ER stress, and inflammation. We propose that enhancing FAOx in hypothalamic neurons exposed to excess lipids promotes metabolic remodeling that reduces local inflammatory and cell stress responses. This shift would restore mitochondrial function such that increased FAOx can produce hypothalamic neuronal ATP and lead to decreased food intake and body weight to improve systemic metabolism.

  13. Psychophysiological responses to stress after stress management training in patients with rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Sabine J M de Brouwer

    Full Text Available BACKGROUND: Stress management interventions may prove useful in preventing the detrimental effects of stress on health. This study assessed the effects of a stress management intervention on the psychophysiological response to stress in patients with rheumatoid arthritis (RA. METHODS: Seventy-four patients with RA, who were randomly assigned to either a control group or a group that received short-term stress management training, performed a standardized psychosocial stress task (Trier Social Stress Test; TSST 1 week after the stress management training and at a 9-week follow-up. Psychological and physical functioning, and the acute psychophysiological response to the stress test were assessed. RESULTS: Patients in the intervention group showed significantly lower psychological distress levels of anxiety after the training than did the controls. While there were no between-group differences in stress-induced tension levels, and autonomic (α-amylase or endocrine (cortisol responses to the stress test 1 week after the intervention, levels of stress-induced tension and cortisol were significantly lower in the intervention group at the 9-week follow-up. Overall, the response to the intervention was particularly evident in a subgroup of patients with a psychological risk profile. CONCLUSION: A relatively short stress management intervention can improve psychological functioning and influences the psychophysiological response to stress in patients with RA, particularly those psychologically at risk. These findings might help understand how stress can affect health and the role of individual differences in stress responsiveness. TRIAL REGISTRATION: TrialRegister.nl NTR1193.

  14. Proteomic studies of drought stress response in Fabaceae

    Directory of Open Access Journals (Sweden)

    Tanja ZADRAŽNIK

    2015-11-01

    Full Text Available Drought stress is a serious threat to crop production that influences plant growth and development and subsequently causes reduced quantity and quality of the yield. Plant stress induces changes in cell metabolism, which includes differential expression of proteins. Proteomics offer a powerful approach to analyse proteins involved in drought stress response of plants. Analyses of changes in protein abundance of legumes under drought stress are very important, as legumes play an important role in human and animal diet and are often exposed to drought. The presented results of proteomic studies of selected legumes enable better understanding of molecular mechanisms of drought stress response. The study of drought stress response of plants with proteomic approach may contribute to the development of potential drought-response markers and to the development of drought-tolerant cultivars of different legume crop species.

  15. Stress in university students and cardiovascular response to academic stressors

    OpenAIRE

    Guimarães, Teresa; Silva, Ana Patrícia; Monteiro, Iolanda; Gomes, Rui

    2014-01-01

    Introduction: University students are frequently exposed to events that can cause stress and anxiety, producing elevated cardiovascular responses. Repeated exposure to academic stress has implications to students’ success and well-being and may contribute to the development of long-term health problems. Objective: To identify stress levels and coping strategies in university students and assess the impact of stress experience in heart rate variability (HRV). Methods: 17 university students, 1...

  16. Proteomic studies of drought stress response in Fabaceae

    OpenAIRE

    Zadražnik, Tanja; Jelka ŠUŠTAR-VOZLIČ

    2015-01-01

    Drought stress is a serious threat to crop production that influences plant growth and development and subsequently causes reduced quantity and quality of the yield. Plant stress induces changes in cell metabolism, which includes differential expression of proteins. Proteomics offer a powerful approach to analyse proteins involved in drought stress response of plants. Analyses of changes in protein abundance of legumes under drought stress are very important, as legumes play an important role...

  17. Hormonal modulation of the heat shock response: insights from fish with divergent cortisol stress responses

    DEFF Research Database (Denmark)

    LeBlanc, Sacha; Höglund, Erik; Gilmour, Kathleen M.;

    2012-01-01

    shock response, we capitalized on two lines of rainbow trout specifically bred for their high (HR) and low (LR) cortisol response to stress. We predicted that LR fish, with a low cortisol but high catecholamine response to stress, would induce higher levels of HSPs after acute heat stress than HR trout......Acute temperature stress in animals results in increases in heat shock proteins (HSPs) and stress hormones. There is evidence that stress hormones influence the magnitude of the heat shock response; however, their role is equivocal. To determine whether and how stress hormones may affect the heat....... We found that HR fish have significantly higher increases in both catecholamines and cortisol compared with LR fish, and LR fish had no appreciable stress hormone response to heat shock. This unexpected finding prevented further interpretation of the hormonal modulation of the heat shock response...

  18. Context and strain-dependent behavioral response to stress

    OpenAIRE

    Baum Amber E; Ahmadiyeh Nasim; Andrus Brian M; Dennis Kristen; Nosek Katarzyna; Woods Leah; Redei Eva E

    2008-01-01

    Abstract Background This study posed the question whether strain differences in stress-reactivity lead to differential behavioral responses in two different tests of anxiety. Strain differences in anxiety-measures are known, but strain differences in the behavioral responses to acute prior stress are not well characterized. Methods We studied male Fisher 344 (F344) and Wistar Kyoto (WKY) rats basally and immediately after one hour restraint stress. To distinguish between the effects of novelt...

  19. Arabidopsis PYL8 Plays an Important Role for ABA Signaling and Drought Stress Responses

    OpenAIRE

    Lim, Chae Woo; Baek, Woonhee; Han, Sang-Wook; Lee, Sung Chul

    2013-01-01

    Plants are frequently exposed to numerous environmental stresses such as dehydration and high salinity, and have developed elaborate mechanisms to counteract the deleterious effects of stress. The phytohormone abscisic acid (ABA) plays a critical role as an integrator of plant responses to water-limited condition to activate ABA signal transduction pathway. Although perception of ABA has been suggested to be important, the function of each ABA receptor remains elusive in dehydration condition...

  20. Unraveling uranium induced oxidative stress related responses in Arabidopsis thaliana seedlings. Part II: responses in the leaves and general conclusions

    Energy Technology Data Exchange (ETDEWEB)

    Vanhoudt, Nathalie, E-mail: nvanhoud@sckcen.be [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Cuypers, Ann [Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Horemans, Nele [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Remans, Tony; Opdenakker, Kelly; Smeets, Karen [Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Bello, Daniel Martinez [Hasselt University, Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Agoralaan Building D, 3590 Diepenbeek (Belgium); Havaux, Michel [Commissariat a l' Energie Atomique (CEA)/Cadarache, Direction des Sciences du Vivant, Departement d' Ecophysiologie Vegetale et de Microbiologie, Laboratoire d' Ecophysiologie de la Photosynthese, 13108 Saint-Paul-lez-Durance (France); Wannijn, Jean; Van Hees, May [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Vangronsveld, Jaco [Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Vandenhove, Hildegarde [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium)

    2011-06-15

    The cellular redox balance seems an important modulator under heavy metal stress. While for other heavy metals these processes are well studied, oxidative stress related responses are also known to be triggered under uranium stress but information remains limited. This study aimed to further unravel the mechanisms by which plants respond to uranium stress. Seventeen-day-old Arabidopsis thaliana seedlings, grown on a modified Hoagland solution under controlled conditions, were exposed to 0, 0.1, 1, 10 and 100 {mu}M uranium for 1, 3 and 7 days. While in Part I of this study oxidative stress related responses in the roots were discussed, this second Part II discusses oxidative stress related responses in the leaves and general conclusions drawn from the results of the roots and the leaves will be presented. As several responses were already visible following 1 day exposure, when uranium concentrations in the leaves were negligible, a root-to-shoot signaling system was suggested in which plastids could be important sensing sites. While lipid peroxidation, based on the amount of thiobarbituric acid reactive compounds, was observed after exposure to 100 {mu}M uranium, affecting membrane structure and function, a transient concentration dependent response pattern was visible for lipoxygenase initiated lipid peroxidation. This transient character of uranium stress responses in leaves was emphasized by results of lipoxygenase (LOX2) and antioxidative enzyme transcript levels, enzyme capacities and glutathione concentrations both in time as with concentration. The ascorbate redox balance seemed an important modulator of uranium stress responses in the leaves as in addition to the previous transient responses, the total ascorbate concentration and ascorbate/dehydroascorbate redox balance increased in a concentration and time dependent manner. This could represent either a slow transient response or a stable increase with regard to plant acclimation to uranium stress

  1. Effects of orthostasis on endocrine responses to psychosocial stress.

    Science.gov (United States)

    Nater, Urs M; Ditzen, Beate; Strahler, Jana; Ehlert, Ulrike

    2013-12-01

    Standardized psychological procedures have been designed to induce physiological stress responses. However, the impact of standing (orthostasis) on the physiological reaction after psychological stress remains unclear. The purpose of the current analysis was to examine and quantify the relative contribution of orthostasis to the physiological stress response by comparing a "standing with stress" to a "standing without stress" condition. We investigated the effect of standing with and without stress on responses of the sympathetic-adrenomedullary (SAM) system and the hypothalamic-pituitary-adrenal (HPA) axis using a standardized psychosocial stress protocol (Trier Social Stress Test) and a non-stress condition in a repeated measures design. Subjects (N=30) were exposed to both conditions in randomized order and had to maintain a standing, upright position for 10minutes. In the "standing with stress" condition, significant increases in repeatedly assessed plasma norepinephrine (NE) and epinephrine (EP), as well as in saliva cortisol were found, while in the "standing without stress" condition, no significant changes in plasma epinephrine and saliva cortisol were observed. Calculations of the relative contribution of orthostasis to physiological stress responses revealed that 25.61% of the NE increase, 82.94% of the EP increase, and 68.91% of the cortisol increase, could be attributed to psychosocial stress adjusted for the effects of orthostasis and basal endocrine output. Although these results are indicative for a marked endocrine reaction that is caused by psychosocial stress alone, our findings show that the contribution of orthostasis must be taken into account when interpreting endocrine data collected in a psychosocial stress test.

  2. Brain Endoplasmic Reticulum Stress Mechanistically Distinguishes the Saline-Intake and Hypertensive Response to DOCA-Salt

    OpenAIRE

    Jo, Fusakazu; Jo, Hiromi; Hilzendeger, Aline M.; Thompson, Anthony P.; Cassell, Martin D.; Rutkowski, D. Thomas; Davisson, Robin L.; Grobe, Justin L.; Sigmund, Curt D.

    2015-01-01

    Endoplasmic reticulum stress has become an important mechanism in hypertension. We examined the role of endoplasmic reticulum stress in mediating the increased saline intake and hypertensive effects in response to DOCA-salt. Intracerebroventricular delivery of the endoplasmic reticulum stress-reducing chemical chaperone Tauroursodeoxycholic acid did not affect the magnitude of hypertension, but markedly decreased saline intake in response to DOCA-salt. Increased saline intake returned after T...

  3. Disrupted glucocorticoid--Immune interactions during stress response in schizophrenia.

    Science.gov (United States)

    Chiappelli, Joshua; Shi, Qiaoyun; Kodi, Priyadurga; Savransky, Anya; Kochunov, Peter; Rowland, Laura M; Nugent, Katie L; Hong, L Elliot

    2016-01-01

    Glucocorticoid and immune pathways typically interact dynamically to optimize adaptation to stressful environmental challenges. We tested the hypothesis that a dysfunctional glucocorticoid-immune relationship contributes to abnormal stress response in schizophrenia. Saliva samples from 34 individuals with schizophrenia (20 male, 14 female) and 40 healthy controls (20 male, 20 female) were collected prior to and at 3 time points following completion of a computerized psychological challenge meant to be frustrating. Salivary concentrations of cortisol and interleukin-6 (IL-6) and their response to the challenge were examined. Both cortisol and IL-6 significantly increased in response to stress in the combined sample (both pschizophrenia patients (r=.379, p=.027). The trends were significantly different (Z=3.7, p=.0002). This stress paradigm induces a rise in both cortisol and IL-6. In healthy controls, a more robust acute cortisol response was associated with a steeper decline of IL-6 levels following stress, corresponding to the expected anti-inflammatory effects of cortisol. Patients exhibited the opposite relationship, suggesting an inability to down-regulate inflammatory responses to psychological stress in schizophrenia; or even a paradoxical increase of IL-6 response. This finding may partially underlie abnormalities in inflammatory and stress pathways previously found in the illness, implicating dysregulated stress response in the chronic inflammatory state in schizophrenia.

  4. Molecular Mechanism of Rice in Response to Salt Stress

    Institute of Scientific and Technical Information of China (English)

    E Zhi-guo; ZHANG Li-jing; WANG Lei

    2011-01-01

    Rice is moderately sensitive to salinity,and the response to salt stress is a complex process,including the perception and transduction of salt stress signal,the activation of specific transcriptional factors and the expression of downstream stress-responsive genes.The functions of Na+ transporters which are involved in the maintenance and reconstruction of the ion homeostasis,transcriptional regulators and osmotic regulation genes were reviewed.Salt tolerance of plants are enhanced by Na+ vacuolar compartmentation or efflux or high levels of osmoprotectants accumulation in cytoplasm.%Rice is moderately sensitive to salinity,and the response to salt stress is a complex process,including the perception and transduction of salt stress signal,the activation of specific transcriptional factors and the expression of downstream stress-respon

  5. Sex differences in synaptic plasticity in stress-responsive brain regions following chronic variable stress

    OpenAIRE

    Carvalho-Netto, Eduardo F.; Myers, Brent; Jones, Kenneth; Solomon, Matia B.; Herman, James P.

    2011-01-01

    Increased stress responsiveness is implicated in the etiology of mood and anxiety disorders, including depression and post-traumatic stress disorder. Additionally, stress-related affective disorders have a higher incidence in women than men. Chronic stress in rodents produces numerous neuromorphological changes in a variety of limbic brain regions. Here, we examined the sex-dependent differences in presynaptic innervation of the paraventricular nucleus of the hypothalamus (PVN), prefrontal co...

  6. Molecular mechanisms of the plant heat stress response

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Ai-Li; Ding, Yan-Fei; Jiang, Qiong [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China); Zhu, Cheng, E-mail: pzhch@cjlu.edu.cn [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China)

    2013-03-08

    Highlights: ► This review elaborates the response networks of heat stress in plants. ► It elaborates proteins responding to heat stress in special physiological period. ► The proteins and pathways have formed a basic network of the heat stress response. ► Achievements of the various technologies are also combined. -- Abstract: High temperature has become a global concern, which seriously affects the growth and production of plants, particularly crops. Thus, the molecular mechanism of the heat stress response and breeding of heat-tolerant plants is necessary to protect food production and ensure crop safety. This review elaborates on the response networks of heat stress in plants, including the Hsf and Hsp response pathways, the response of ROS and the network of the hormones. In addition, the production of heat stress response elements during particular physiological periods of the plant is described. We also discuss the existing problems and future prospects concerning the molecular mechanisms of the heat stress response in plants.

  7. Post-stress rumination predicts HPA axis responses to repeated acute stress.

    Science.gov (United States)

    Gianferante, Danielle; Thoma, Myriam V; Hanlin, Luke; Chen, Xuejie; Breines, Juliana G; Zoccola, Peggy M; Rohleder, Nicolas

    2014-11-01

    Failure of the hypothalamus-pituitary-adrenal (HPA) axis to habituate to repeated stress exposure is related with adverse health outcomes, but our knowledge of predictors of non-habituation is limited. Rumination, defined as repetitive and unwanted past-centered negative thinking, is related with exaggerated HPA axis stress responses and poor health outcomes. The aim of this study was to test whether post-stress rumination was related with non-habituation of cortisol to repeated stress exposure. Twenty-seven participants (n=13 females) were exposed to the Trier Social Stress Test (TSST) twice on consecutive afternoons. Post-stress rumination was measured after the first TSST, and HPA axis responses were assessed by measuring salivary cortisol 1 min before, and 1, 10, 20, 60, and 120 min after both TSSTs. Stress exposure induced HPA axis activation on both days, and this activation showed habituation indicated by lower responses to the second TSST (F=3.7, p=0.015). Post-stress rumination after the first TSST was associated with greater cortisol reactivity after the initial stress test (r=0.45, pHPA axis responses. This finding implicates rumination as one possible mechanism mediating maladaptive stress response patterns, and it might also offer a pathway through which rumination might lead to negative health outcomes.

  8. Involvement of Histone Modifications in Plant Abiotic Stress Responses

    Institute of Scientific and Technical Information of China (English)

    Lianyu Yuan; Xuncheng Liu; Ming Luo; Songguang Yang; Keqiang Wu

    2013-01-01

    As sessile organisms, plants encounter various environmental stimuli including abiotic stresses during their lifecycle. To survive under adverse conditions, plants have evolved intricate mechanisms to perceive external signals and respond accordingly. Responses to various stresses largely depend on the plant capacity to modulate the transcriptome rapidly and specifically. A number of studies have shown that the molecular mechanisms driving the responses of plants to environmental stresses often depend on nucleosome histone post-translational modifications including histone acetylation, methylation, ubiquitination, and phosphorylation. The combined effects of these modifications play an essential role in the regulation of stress responsive gene expression. In this review, we highlight our current understanding of the epigenetic mechanisms of histone modifications and their roles in plant abiotic stress response.

  9. Stress corrosion cracking of zirconium in nitric acid

    International Nuclear Information System (INIS)

    The susceptibility of zirconium and its common alloys to stress corrosion cracking (SCC) in nitric acid was investigated by slow strain-rate and constant deflection techniques. Cracking occurred at 250C over a wide range of acid concentrations and electrochemical potentials. The crack velocity increased slightly with increasing temperature. The failure mode was transgranular and the morphology was similar to SCC failures of zirconium alloys in other environments. The fracture was very orientation-dependent suggesting that it occurs on a single crystallographic plane in the material. The results of the study are not consistent with a hydrogen mechanism for cracking

  10. Natural variation in abiotic stress responsive gene expression and local adaptation to climate in Arabidopsis thaliana.

    Science.gov (United States)

    Lasky, Jesse R; Des Marais, David L; Lowry, David B; Povolotskaya, Inna; McKay, John K; Richards, James H; Keitt, Timothy H; Juenger, Thomas E

    2014-09-01

    Gene expression varies widely in natural populations, yet the proximate and ultimate causes of this variation are poorly known. Understanding how variation in gene expression affects abiotic stress tolerance, fitness, and adaptation is central to the field of evolutionary genetics. We tested the hypothesis that genes with natural genetic variation in their expression responses to abiotic stress are likely to be involved in local adaptation to climate in Arabidopsis thaliana. Specifically, we compared genes with consistent expression responses to environmental stress (expression stress responsive, "eSR") to genes with genetically variable responses to abiotic stress (expression genotype-by-environment interaction, "eGEI"). We found that on average genes that exhibited eGEI in response to drought or cold had greater polymorphism in promoter regions and stronger associations with climate than those of eSR genes or genomic controls. We also found that transcription factor binding sites known to respond to environmental stressors, especially abscisic acid responsive elements, showed significantly higher polymorphism in drought eGEI genes in comparison to eSR genes. By contrast, eSR genes tended to exhibit relatively greater pairwise haplotype sharing, lower promoter diversity, and fewer nonsynonymous polymorphisms, suggesting purifying selection or selective sweeps. Our results indicate that cis-regulatory evolution and genetic variation in stress responsive gene expression may be important mechanisms of local adaptation to climatic selective gradients.

  11. Nitric Oxide Signaling in Plant Responses to Abiotic Stresses

    Institute of Scientific and Technical Information of China (English)

    Weihua Qiao; LiuMin Fan

    2008-01-01

    Nitric oxide (NO) plays important roles in diverse physiological processes In plants. NO can provoke both beneficial and harmful effects, which depend on the concentration and location of NO in plant cells. This review is focused on NO synthesis and the functions of NO in plant responses to abiotic environmental stresses. Abiotic stresses mostly induce NO production in plants. NO alleviates the harmfulness of reactive oxygen species, and reacts with other target molecules, and regulates the expression of stress responsive genes under various stress conditions.

  12. [Cardioprotective properties of new glutamic acid derivative under stress conditions].

    Science.gov (United States)

    Perfilova, V N; Sadikova, N V; Berestovitskaia, V M; Vasil'eva, O S

    2014-01-01

    The effect of new glutamic acid derivative on the cardiac ino- and chronotropic functions has been studied in experiments on rats exposed to 24-hour immobilization-and-pain stress. It is established that glutamic acid derivative RGPU-238 (glufimet) at a dose of 28.7 mg/kg increases the increment of myocardial contractility and relaxation rates and left ventricular pressure in stress-tested animals by 13 1,1, 72.4, and 118.6%, respectively, as compared to the control group during the test for adrenoreactivity. Compound RGPU-238 increases the increment of the maximum intensity of myocardium functioning by 196.5 % at 30 sec of isometric workload as compared to the control group. The cardioprotective effect of compound RGPU-238 is 1.5 - 2 times higher than that of the reference drug phenibut. PMID:25365864

  13. AMPK-independent inhibition of human macrophage ER stress response by AICAR.

    Science.gov (United States)

    Boß, Marcel; Newbatt, Yvette; Gupta, Sahil; Collins, Ian; Brüne, Bernhard; Namgaladze, Dmitry

    2016-01-01

    Obesity-associated insulin resistance is driven by inflammatory processes in response to metabolic overload. Obesity-associated inflammation can be recapitulated in cell culture by exposing macrophages to saturated fatty acids (SFA), and endoplasmic reticulum (ER) stress responses essentially contribute to pro-inflammatory signalling. AMP-activated protein kinase (AMPK) is a central metabolic regulator with established anti-inflammatory actions. Whether pharmacological AMPK activation suppresses SFA-induced inflammation in a human system is unclear. In a setting of hypoxia-potentiated inflammation induced by SFA palmitate, we found that the AMP-mimetic AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) potently suppressed upregulation of ER stress marker mRNAs and pro-inflammatory cytokines. Furthermore, AICAR inhibited macrophage ER stress responses triggered by ER-stressors thapsigargin or tunicamycin. Surprisingly, AICAR acted independent of AMPK or AICAR conversion to 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl monophosphate (ZMP) while requiring intracellular uptake via the equilibrative nucleoside transporter (ENT) ENT1 or the concentrative nucleoside transporter (CNT) CNT3. AICAR did not affect the initiation of the ER stress response, but inhibited the expression of major ER stress transcriptional effectors. Furthermore, AICAR inhibited autophosphorylation of the ER stress sensor inositol-requiring enzyme 1α (IRE1α), while activating its endoribonuclease activity in vitro. Our results suggest that AMPK-independent inhibition of ER stress responses contributes to anti-inflammatory and anti-diabetic effects of AICAR. PMID:27562249

  14. Dynamical theory of active cellular response to external stress.

    Science.gov (United States)

    De, Rumi; Safran, Samuel A

    2008-09-01

    We present a comprehensive, theoretical treatment of the orientational response to external stress of active, contractile cells embedded in a gel-like elastic medium. The theory includes both the forces that arise from the deformation of the matrix as well as forces due to the internal regulation of the stress fibers and focal adhesions of the cell. We calculate the time-dependent response of both the magnitude and the direction of the elastic dipole that characterizes the active forces exerted by the cell, for various situations. For static or quasistatic external stress, cells orient parallel to the stress while for high frequency dynamic external stress, cells orient nearly perpendicular. Both numerical and analytical calculations of these effects are presented. In addition we predict the relaxation time for the cellular response for both slowly and rapidly varying external stresses; several characteristic scaling regimes for the relaxation time as a function of applied frequency are predicted. We also treat the case of cells for which the regulation of the stress fibers and focal adhesions is controlled by strain (instead of stress) and show that the predicted dependence of the cellular orientation on the Poisson ratio of the matrix can differentiate strain vs stress regulation of cellular response.

  15. Dynamical theory of active cellular response to external stress

    Science.gov (United States)

    de, Rumi; Safran, Samuel A.

    2008-09-01

    We present a comprehensive, theoretical treatment of the orientational response to external stress of active, contractile cells embedded in a gel-like elastic medium. The theory includes both the forces that arise from the deformation of the matrix as well as forces due to the internal regulation of the stress fibers and focal adhesions of the cell. We calculate the time-dependent response of both the magnitude and the direction of the elastic dipole that characterizes the active forces exerted by the cell, for various situations. For static or quasistatic external stress, cells orient parallel to the stress while for high frequency dynamic external stress, cells orient nearly perpendicular. Both numerical and analytical calculations of these effects are presented. In addition we predict the relaxation time for the cellular response for both slowly and rapidly varying external stresses; several characteristic scaling regimes for the relaxation time as a function of applied frequency are predicted. We also treat the case of cells for which the regulation of the stress fibers and focal adhesions is controlled by strain (instead of stress) and show that the predicted dependence of the cellular orientation on the Poisson ratio of the matrix can differentiate strain vs stress regulation of cellular response.

  16. Stearic acid protects primary cultured cortical neurons against oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Ze-jian WANG; Cui-ling LIANG; Guang-mei LI; Cai-yi YU; Ming YIN

    2007-01-01

    Aim: To observe the effects of stearic acid against oxidative stress in primary cultured cortical neurons. Methods: Cortical neurons were exposed to glutamate,hydrogen peroxide (H202), or NaN3 insult in the presence or absence of stearic acid. Cell viability of cortical neurons was determined by MTT assay and LDH release. Endogenous antioxidant enzymes activity[superoxide dismutases (SOD),glutathione peroxidase (GSH-Px), and catalase (CAT)] and lipid peroxidation in cultured cortical neurons were evaluated using commercial kits. {3-[1(p-chloro-benzyl)-5-(isopropyl)-3-t-butylthiondol-2-yl]-2,2-dimethylpropanoic acid, Na}[MK886; 5 pmol/L; a noncompetitive inhibitor of proliferator-activated receptor(PPAR)α], bisphenol A diglycidyl ether (BADGE; 100 μmol/L; an antagonist of PPARγ), and cycloheximide (CHX; 30 μmol/L, an inhibitor of protein synthesis)were tested for their effects on the neuroprotection afforded by stearic acid.Western blotting was used to determine the PPARγ protein level in cortical neurons.Results: Stearic acid dose-dependently protected cortical neurons against glutamate or H202 injury and increased glutamate uptake in cultured neurons.This protection was concomitant to the inhibition of lipid peroxidation and to the promotion activity of Cu/Zn SOD and CAT in cultured cortical neurons. Its neuroprotective effects were completely blocked by BADGE and CHX. After incubation with H2O2 for 24 h, the expression of the PPARγ protein decreased significantly (P<0.05), and the inhibitory effect of H2O2 on the expression of PPARγ can be attenuated by stearic acid. Conclusion: Stearic acid can protect cortical neurons against oxidative stress by boosting the internal antioxidant enzymes.Its neuroprotective effect may be mainly mediated by the activation of PPARγ and new protein synthesis in cortical neurons.

  17. Oxidative Stress in Dog with Heart Failure: The Role of Dietary Fatty Acids and Antioxidants

    Directory of Open Access Journals (Sweden)

    Emmanuelle Sagols

    2011-01-01

    Full Text Available In dogs with heart failure, cell oxygenation and cellular metabolism do not work properly, leading to the production of a large amount of free radicals. In the organism, these free radicals are responsible of major cellular damages: this is oxidative stress. However, a suitable food intake plays an important role in limiting this phenomenon: on the one hand, the presence of essential fatty acids in the composition of membranes decreases sensitivity of cells to free radicals and constitutes a first protection against the oxidative stress; on the other hand, coenzyme Q10, vitamin E, and polyphenols are antioxidant molecules which can help cells to neutralize these free radicals.

  18. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress

    Science.gov (United States)

    Martinez, Vicente; Mestre, Teresa C.; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A.; Mittler, Ron; Rivero, Rosa M.

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance. PMID:27379130

  19. Extracytoplasmic Stress Responses Induced by Antimicrobial Cationic Polyethylenimines

    OpenAIRE

    Lander, Blaine A.; Checchi, Kyle D.; Koplin, Stephen A.; Smith, Virginia F.; Domanski, Tammy L.; Isaac, Daniel D.; Lin, Shirley

    2012-01-01

    The ability of an antimicrobial, cationic polyethylenimine (PEI+) to induce the three known extracytoplasmic stress responses of Escherichia coli was quantified. Exposure of E. coli to PEI+ in solution revealed specific, concentration-dependent induction of the Cpx extracytoplasmic cellular stress response, ~2.0-2.5 fold at 320 μg/mL after 1.5 hours without significant induction of the σE or Bae stress responses. In comparison, exposure of E. coli to a non-antimicrobial polymer, polyethylene ...

  20. Regulation of dopamine system responsivity and its adaptive and pathological response to stress

    OpenAIRE

    Belujon, Pauline; Grace, Anthony A.

    2015-01-01

    Although, historically, the norepinephrine system has attracted the majority of attention in the study of the stress response, the dopamine system has also been consistently implicated. It has long been established that stress plays a crucial role in the pathogenesis of psychiatric disorders. However, the neurobiological mechanisms that mediate the stress response and its effect in psychiatric diseases are not well understood. The dopamine system can play distinct roles in stress and psychiat...

  1. Stress Response and Translation Control in Rotavirus Infection.

    Science.gov (United States)

    López, Susana; Oceguera, Alfonso; Sandoval-Jaime, Carlos

    2016-01-01

    The general stress and innate immune responses are closely linked and overlap at many levels. The outcomes of these responses serve to reprogram host expression patterns to prevent viral invasions. In turn, viruses counter attack these cell responses to ensure their replication. The mechanisms by which viruses attempt to control host cell responses are as varied as the number of different virus families. One of the most recurrent strategies used by viruses to control the antiviral response of the cell is to hijack the translation machinery of the host, such that viral proteins are preferentially synthesized, while the expression of the stress and antiviral responses of the cell are blocked at the translation level. Here, we will review how rotaviruses, an important agent of acute severe gastroenteritis in children, overcome the stress responses of the cell to establish a productive infectious cycle. PMID:27338442

  2. Stress Response and Translation Control in Rotavirus Infection

    Directory of Open Access Journals (Sweden)

    Susana López

    2016-06-01

    Full Text Available The general stress and innate immune responses are closely linked and overlap at many levels. The outcomes of these responses serve to reprogram host expression patterns to prevent viral invasions. In turn, viruses counter attack these cell responses to ensure their replication. The mechanisms by which viruses attempt to control host cell responses are as varied as the number of different virus families. One of the most recurrent strategies used by viruses to control the antiviral response of the cell is to hijack the translation machinery of the host, such that viral proteins are preferentially synthesized, while the expression of the stress and antiviral responses of the cell are blocked at the translation level. Here, we will review how rotaviruses, an important agent of acute severe gastroenteritis in children, overcome the stress responses of the cell to establish a productive infectious cycle.

  3. Stress Response and Translation Control in Rotavirus Infection

    Science.gov (United States)

    López, Susana; Oceguera, Alfonso; Sandoval-Jaime, Carlos

    2016-01-01

    The general stress and innate immune responses are closely linked and overlap at many levels. The outcomes of these responses serve to reprogram host expression patterns to prevent viral invasions. In turn, viruses counter attack these cell responses to ensure their replication. The mechanisms by which viruses attempt to control host cell responses are as varied as the number of different virus families. One of the most recurrent strategies used by viruses to control the antiviral response of the cell is to hijack the translation machinery of the host, such that viral proteins are preferentially synthesized, while the expression of the stress and antiviral responses of the cell are blocked at the translation level. Here, we will review how rotaviruses, an important agent of acute severe gastroenteritis in children, overcome the stress responses of the cell to establish a productive infectious cycle. PMID:27338442

  4. Stress Generation and Adolescent Depression: Contribution of Interpersonal Stress Responses

    Science.gov (United States)

    Flynn, Megan; Rudolph, Karen D.

    2011-01-01

    This research examined the proposal that ineffective responses to common interpersonal problems disrupt youths' relationships, which, in turn, contributes to depression during adolescence. Youth (86 girls, 81 boys; M age = 12.41, SD = 1.19) and their primary female caregivers participated in a three-wave longitudinal study. Youth completed a…

  5. Antioxidant responses of wheat plants under stress

    Directory of Open Access Journals (Sweden)

    Andréia Caverzan

    2016-03-01

    Full Text Available Abstract Currently, food security depends on the increased production of cereals such as wheat (Triticum aestivum L., which is an important source of calories and protein for humans. However, cells of the crop have suffered from the accumulation of reactive oxygen species (ROS, which can cause severe oxidative damage to the plants, due to environmental stresses. ROS are toxic molecules found in various subcellular compartments. The equilibrium between the production and detoxification of ROS is sustained by enzymatic and nonenzymatic antioxidants. In the present review, we offer a brief summary of antioxidant defense and hydrogen peroxide (H2O2 signaling in wheat plants. Wheat plants increase antioxidant defense mechanisms under abiotic stresses, such as drought, cold, heat, salinity and UV-B radiation, to alleviate oxidative damage. Moreover, H2O2 signaling is an important factor contributing to stress tolerance in cereals.

  6. Effects of regional analgesia on stress responses to pediatric surgery.

    Science.gov (United States)

    Wolf, Andrew R

    2012-01-01

    Invasive surgery induces a combination of local response to tissue injury and generalized activation of systemic metabolic and hormonal pathways via afferent nerve pathways and the central nervous system. The local inflammatory responses and the parallel neurohumoral responses are not isolated but linked through complex signaling networks, some of which remain poorly understood. The magnitude of the response is broadly related to the site of injury (greater in regions with visceral pain afferents such as abdomen and thorax) and the extent of the trauma. The changes include alterations in metabolic, hormonal, inflammatory, and immune systems that can be collectively termed the stress response. Integral to the stress responses are the effects of nociceptive afferent stimuli on systemic and pulmonary vascular resistance, heart rate, and blood pressure, which are a combination of efferent autonomic response and catecholamine release via the adrenal medulla. Therefore, pain responses, cardiovascular responses, and stress responses need to be considered as different aspects of a combined bodily reaction to surgery and trauma. It is important at the outset to understand that not all components of the stress response are suppressed together and that this is important when discussing different analgesic modalities (i.e. opioids vs regional anesthesia). For example, in terms of the use of fentanyl in the infant, the dose required to provide analgesia (1-5 mcg·kg(-1)) is less than that required for hemodynamic stability in response to stimuli (5-10 mcg·kg(-1)) (1) and that this in turn is less than that required to suppress most aspects of the stress response (25-50 mcg·kg(-1)) (2). In contrast to this considerable dose dependency, central local anesthetic blocks allow blockade of the afferent and efferent sympathetic pathways at relatively low doses resulting in profound suppression of hemodynamic and stress responses to surgery. PMID:21999144

  7. Modulation of immune responses in stress by Yoga

    OpenAIRE

    Arora Sarika; Bhattacharjee Jayashree

    2008-01-01

    Stress is a constant factor in today′s fastpaced life that can jeopardize our health if left unchecked. It is only in the last half century that the role of stress in every ailment from the common cold to AIDS has been emphasized, and the mechanisms involved in this process have been studied. Stress influences the immune response presumably through the activation of the hypothalamic-pituitary adrenal axis, hypothalamic pituitary-gonadal axis, and the sympathetic-adrenal-medullary syste...

  8. Sympathetic neural responses to mental stress during acute simulated microgravity

    OpenAIRE

    Durocher, John J.; Schwartz, Christopher E.; Carter, Jason R.

    2009-01-01

    Neural and cardiovascular responses to mental stress and acute 6° head-down tilt (HDT) were examined separately and combined. We hypothesized sympathoexcitation during mental stress, sympathoinhibition during HDT, and an additive neural interaction during combined mental stress and HDT. Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate (HR) were recorded in 16 healthy subjects (8 men, 8 women) in the supine position during three randomized trials: 1) menta...

  9. Acute Stress Reduces Reward Responsiveness: Implications for Depression

    OpenAIRE

    Bogdan, Ryan; Pizzagalli, Diego

    2006-01-01

    Background: Stress, one of the strongest risk factors for depression, has been linked to "anbedonic" behavior and dysfunctional reward-related neural circuitry in preclinical models. Methods: To test if acute stress reduces reward responsiveness (i.e., the ability to modulate behavior as a function of past reward), a signal-detection task coupled with a differential reinforcement schedule was utilized. Eighty female participants completed the task under both a stress condition, either threat-...

  10. The Teenage Brain: The Stress Response and the Adolescent Brain

    OpenAIRE

    Romeo, Russell D.

    2013-01-01

    Adolescence is a time of many psychosocial and physiological changes. One such change is how an individual responds to stressors. Specifically, adolescence is marked by significant shifts in hypothalamic-pituitary-adrenal (HPA) axis reactivity, resulting in heightened stress-induced hormonal responses. It is presently unclear what mediates these changes in stress reactivity and what impacts they may have on an adolescent individual. However, stress-sensitive limbic and corti...

  11. Habitual Response to Stress in Recovering Adolescent Anorexic Patients

    Science.gov (United States)

    Miller, Samantha P.; Erickson, Sarah J.; Branom, Christina; Steiner, Hans

    2009-01-01

    Objective: Although previous research has investigated the stress response in acutely anorexic patients, there is currently little research addressing this response in recovering adolescent anorexic girls. Therefore, this study investigated partially and fully weight-restored anorexic adolescent girls' psychological and physiological response to a…

  12. Quantification of Bacillus cereus stress responses

    NARCIS (Netherlands)

    Besten, den H.M.W.

    2010-01-01

    The microbial stability and safety of minimally processed foods is controlled by a deliberate combination of preservation hurdles. However, this preservation strategy is challenged by the ability of spoilage bacteria and food-borne pathogens to adapt to stressing environments providing cell robustne

  13. Acute Stress Response in Critically Ill Children

    NARCIS (Netherlands)

    M. den Brinker (Marieke)

    2006-01-01

    textabstractThe understanding of the endocrine changes in critically ill children is important, as it provides insights in the pathophysiology of the acute stress in children and its differences compared with adults. Furthermore, it delineates prognostic factors for survival and supports the rati

  14. Cell Wall Metabolism in Response to Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Hyacinthe Le Gall

    2015-02-01

    Full Text Available This review focuses on the responses of the plant cell wall to several abiotic stresses including drought, flooding, heat, cold, salt, heavy metals, light, and air pollutants. The effects of stress on cell wall metabolism are discussed at the physiological (morphogenic, transcriptomic, proteomic and biochemical levels. The analysis of a large set of data shows that the plant response is highly complex. The overall effects of most abiotic stress are often dependent on the plant species, the genotype, the age of the plant, the timing of the stress application, and the intensity of this stress. This shows the difficulty of identifying a common pattern of stress response in cell wall architecture that could enable adaptation and/or resistance to abiotic stress. However, in most cases, two main mechanisms can be highlighted: (i an increased level in xyloglucan endotransglucosylase/hydrolase (XTH and expansin proteins, associated with an increase in the degree of rhamnogalacturonan I branching that maintains cell wall plasticity and (ii an increased cell wall thickening by reinforcement of the secondary wall with hemicellulose and lignin deposition. Taken together, these results show the need to undertake large-scale analyses, using multidisciplinary approaches, to unravel the consequences of stress on the cell wall. This will help identify the key components that could be targeted to improve biomass production under stress conditions.

  15. Personality, Stressful Life Events, and Treatment Response in Major Depression

    Science.gov (United States)

    Bulmash, Eric; Harkness, Kate L.; Stewart, Jeremy G.; Bagby, R. Michael

    2009-01-01

    The current study examined whether the personality traits of self-criticism or dependency moderated the effect of stressful life events on treatment response. Depressed outpatients (N = 113) were randomized to 16 weeks of cognitive-behavioral therapy, interpersonal psychotherapy, or antidepressant medication (ADM). Stressful life events were…

  16. Quorum Sensing Enhances the Stress Response in Vibrio cholerae▿

    OpenAIRE

    Joelsson, Adam; Kan, Biao; Jun ZHU

    2007-01-01

    Vibrio cholerae lives in aquatic environments and causes cholera. Here, we show that quorum sensing enhances V. cholerae viability under certain stress conditions by upregulating the expression of RpoS, and this regulation acts through HapR, suggesting that a quorum-sensing-enhanced stress response plays a role in V. cholerae environmental survival.

  17. Traumatic Experience in Infancy: How Responses to Stress Affect Development

    Science.gov (United States)

    Witten, Molly Romer

    2010-01-01

    Responses to traumatic stress during the earliest years of life can change quickly and can be difficult to identify because of the young child's rapid rate of development. The symptoms of traumatic stress will depend on the child's developmental level and individual coping styles, as well as the quality and nature of the child's most important…

  18. The psychophysiological stress response in psoriasis and rheumatoid arthritis

    NARCIS (Netherlands)

    Brouwer, S.J.M. de; Middendorp, H. van; Stormink, C.; Kraaimaat, F.W.; Sweep, F.C.; Jong, E.M.G.J. de; Schalkwijk, J.; Eijsbouts, A.M.M.; Donders, A.R.T.; Kerkhof, P.C.M. van de; Riel, P.L.C.M. van; Evers, A.W.M.

    2014-01-01

    BACKGROUND: Psychosocial stress can be a risk factor for the maintenance and exacerbation of chronic inflammatory diseases, such as psoriasis and rheumatoid arthritis (RA). OBJECTIVES: To gain insight into the specificity of the psychophysiological stress response during chronic inflammation, we ass

  19. Differentiating anticipatory from reactive cortisol responses to psychosocial stress

    NARCIS (Netherlands)

    Engert, V.; Efanov, S.I.; Duchesne, A.; Vogel, S.; Corbo, V.; Pruessner, J.C.

    2013-01-01

    Most psychosocial stress studies assess the overall cortisol response without further identifying the temporal dynamics within hormone levels. It has been shown, however, that the amplitude of anticipatory cortisol stress levels has a unique predictive value for psychological health. So far, no "bes

  20. Shared and unique responses of plants to multiple individual stresses and stress combinations: physiological and molecular mechanisms

    OpenAIRE

    Pandey, Prachi; Ramegowda, Venkategowda; Senthil-Kumar, Muthappa

    2015-01-01

    In field conditions, plants are often simultaneously exposed to multiple biotic and abiotic stresses resulting in substantial yield loss. Plants have evolved various physiological and molecular adaptations to protect themselves under stress combinations. Emerging evidences suggest that plant responses to a combination of stresses are unique from individual stress responses. In addition, plants exhibit shared responses which are common to individual stresses and stress combination. In this rev...

  1. Oxidative stress response pathways: Fission yeast as archetype

    DEFF Research Database (Denmark)

    Papadakis, Manos A.; Workman, Christopher

    2015-01-01

    Schizosaccharomyces pombe is a popular model eukaryotic organism to study diverse aspects of mammalian biology, including responses to cellular stress triggered by redox imbalances within its compartments. The review considers the current knowledge on the signaling pathways that govern the...

  2. [The effect of stressor experiences and optimism upon stress responses].

    Science.gov (United States)

    Tonan, K; Sonoda, A

    1994-10-01

    The present studies investigated whether or not optimism/pessimism is a cognitive mediator of future depression for people who have experienced many negative life events. Subjects were administered optimism scales, stress response scales at Time 1. They then completed the stressor scale and stress response scales at Time 2, about six weeks later. The results showed the interaction of stressor experiences and optimistic diathesis: Subjects who have higher stressor experiences and higher stable and global explanatory style for negative events showed higher depressive responses. Other indices of optimistic diathesis--Life Orientation, Cognitive Style, and Internality dimension of Attributional Style--did not produce this interaction effect. Moreover, this interaction did not appear in the psychological stress response other than depression. These results were consistent with diathesis-stress model of depression. PMID:7861687

  3. GH3-mediated auxin homeostasis links growth regulation with stress adaptation response in Arabidopsis.

    Science.gov (United States)

    Park, Jung-Eun; Park, Ju-Young; Kim, Youn-Sung; Staswick, Paul E; Jeon, Jin; Yun, Ju; Kim, Sun-Young; Kim, Jungmook; Lee, Yong-Hwan; Park, Chung-Mo

    2007-03-30

    Plants constantly monitor environmental fluctuations to optimize their growth and metabolism. One example is adaptive growth occurring in response to biotic and abiotic stresses. Here, we demonstrate that GH3-mediated auxin homeostasis is an essential constituent of the complex network of auxin actions that regulates stress adaptation responses in Arabidopsis. Endogenous auxin pool is regulated, at least in part, through negative feedback by a group of auxin-inducible GH3 genes encoding auxin-conjugating enzymes. An Arabidopsis mutant, wes1-D, in which a GH3 gene WES1 is activated by nearby insertion of the (35)S enhancer, exhibited auxin-deficient traits, including reduced growth and altered leaf shape. Interestingly, WES1 is also induced by various stress conditions as well as by salicylic acid and abscisic acid. Accordingly, wes1-D was resistant to both biotic and abiotic stresses, and stress-responsive genes, such as pathogenesis-related genes and CBF genes, were upregulated in this mutant. In contrast, a T-DNA insertional mutant showed reduced stress resistance. We therefore propose that GH3-mediated growth suppression directs reallocation of metabolic resources to resistance establishment and represents the fitness costs of induced resistance.

  4. A Mycobacterium avium subsp. paratuberculosis predicted serine protease is associated with acid stress and intraphagosomal survival

    Directory of Open Access Journals (Sweden)

    Abirami Kugadas

    2016-08-01

    Full Text Available AbstractThe ability to maintain intra-cellular pH is crucial for bacteria and other microbes to survive in diverse environments, particularly those that undergo fluctuations in pH. Mechanisms of acid resistance remain poorly understood in mycobacteria. Although studies investigating acid stress in M. tuberculosis are gaining traction, few center on Mycobacterium avium subsp. paratuberculosis (MAP, the etiological agent of chronic enteritis in ruminants. We identified a MAP acid stress response network involved in macrophage infection. The central node of this network was MAP0403, a predicted serine protease that shared an 86% amino acid identity with MarP in M. tuberculosis. Previous studies confirmed MarP as a serine protease integral to maintaining intra-bacterial pH and survival in acid in vitro and in vivo. We show that MAP0403 is upregulated in infected macrophage and MAC-T cells and coincided with phagosome acidification. Treatment of mammalian cells with bafilomcyin A1, a potent inhibitor of phagosomal vATPases, diminished MAP0403 transcription. MAP0403 expression was also noted in acidic medium. A surrogate host, M. smegmatis mc2 155, was designed to express MAP0403 and when exposed to either macrophages or in vitro acid stress had increase bacterial cell viability, which corresponds to maintenance of intra-bacterial pH in acidic (pH = 5 conditions. These data suggest that MAP0403 may be the equivalent of MarP in MAP. Future studies confirming MAP0403 as a serine protease and exploring its structure and possible substrates are warranted.

  5. A Mycobacterium avium subsp. paratuberculosis Predicted Serine Protease Is Associated with Acid Stress and Intraphagosomal Survival.

    Science.gov (United States)

    Kugadas, Abirami; Lamont, Elise A; Bannantine, John P; Shoyama, Fernanda M; Brenner, Evan; Janagama, Harish K; Sreevatsan, Srinand

    2016-01-01

    The ability to maintain intra-cellular pH is crucial for bacteria and other microbes to survive in diverse environments, particularly those that undergo fluctuations in pH. Mechanisms of acid resistance remain poorly understood in mycobacteria. Although, studies investigating acid stress in M. tuberculosis are gaining traction, few center on Mycobacterium avium subsp. paratuberculosis (MAP), the etiological agent of chronic enteritis in ruminants. We identified a MAP acid stress response network involved in macrophage infection. The central node of this network was MAP0403, a predicted serine protease that shared an 86% amino acid identity with MarP in M. tuberculosis. Previous studies confirmed MarP as a serine protease integral to maintaining intra-bacterial pH and survival in acid in vitro and in vivo. We show that MAP0403 is upregulated in infected macrophages and MAC-T cells that coincided with phagosome acidification. Treatment of mammalian cells with bafilomcyin A1, a potent inhibitor of phagosomal vATPases, diminished MAP0403 transcription. MAP0403 expression was also noted in acidic medium. A surrogate host, M. smegmatis mc(2) 155, was designed to express MAP0403 and when exposed to either macrophages or in vitro acid stress had increased bacterial cell viability, which corresponds to maintenance of intra-bacterial pH in acidic (pH = 5) conditions, compared to the parent strain. These data suggest that MAP0403 may be the equivalent of MarP in MAP. Future studies confirming MAP0403 as a serine protease and exploring its structure and possible substrates are warranted. PMID:27597934

  6. A Mycobacterium avium subsp. paratuberculosis Predicted Serine Protease Is Associated with Acid Stress and Intraphagosomal Survival

    Science.gov (United States)

    Kugadas, Abirami; Lamont, Elise A.; Bannantine, John P.; Shoyama, Fernanda M.; Brenner, Evan; Janagama, Harish K.; Sreevatsan, Srinand

    2016-01-01

    The ability to maintain intra-cellular pH is crucial for bacteria and other microbes to survive in diverse environments, particularly those that undergo fluctuations in pH. Mechanisms of acid resistance remain poorly understood in mycobacteria. Although, studies investigating acid stress in M. tuberculosis are gaining traction, few center on Mycobacterium avium subsp. paratuberculosis (MAP), the etiological agent of chronic enteritis in ruminants. We identified a MAP acid stress response network involved in macrophage infection. The central node of this network was MAP0403, a predicted serine protease that shared an 86% amino acid identity with MarP in M. tuberculosis. Previous studies confirmed MarP as a serine protease integral to maintaining intra-bacterial pH and survival in acid in vitro and in vivo. We show that MAP0403 is upregulated in infected macrophages and MAC-T cells that coincided with phagosome acidification. Treatment of mammalian cells with bafilomcyin A1, a potent inhibitor of phagosomal vATPases, diminished MAP0403 transcription. MAP0403 expression was also noted in acidic medium. A surrogate host, M. smegmatis mc2 155, was designed to express MAP0403 and when exposed to either macrophages or in vitro acid stress had increased bacterial cell viability, which corresponds to maintenance of intra-bacterial pH in acidic (pH = 5) conditions, compared to the parent strain. These data suggest that MAP0403 may be the equivalent of MarP in MAP. Future studies confirming MAP0403 as a serine protease and exploring its structure and possible substrates are warranted. PMID:27597934

  7. Stability analysis of Reynolds stress response functional candidates

    Energy Technology Data Exchange (ETDEWEB)

    Dafinger, M.; Hallatschek, K. [Max-Planck-Institute for Plasma Physics, EURATOM-IPP Association, Garching (Germany); Itoh, K. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2013-04-15

    Complete information on the behavior of zonal flows in turbulence systems is coded in the turbulent stress response to the respective flow pattern. We show that turbulence stress response functionals containing only the linear first order wavenumber dependence on the flow pattern result in unstable structures up to the system size. A minimal augmentation to reproduce the flow patterns observed in turbulence simulations is discussed.

  8. Anger responses to psychosocial stress predict heart rate and cortisol stress responses in men but not women.

    Science.gov (United States)

    Lupis, Sarah B; Lerman, Michelle; Wolf, Jutta M

    2014-11-01

    While previous research has suggested that anger and fear responses to stress are linked to distinct sympathetic nervous system (SNS) stress responses, little is known about how these emotions predict hypothalamus-pituitary-adrenal (HPA) axis reactivity. Further, earlier research primarily relied on retrospective self-report of emotion. The current study aimed at addressing both issues in male and female individuals by assessing the role of anger and fear in predicting heart rate and cortisol stress responses using both self-report and facial coding analysis to assess emotion responses. We exposed 32 healthy students (18 female; 19.6±1.7 yr) to an acute psychosocial stress paradigm (TSST) and measured heart rate and salivary cortisol levels throughout the protocol. Anger and fear before and after stress exposure was assessed by self-report, and video recordings of the TSST were assessed by a certified facial coder to determine emotion expression (FACS). Self-reported emotions and emotion expressions did not correlate (all p>.23). Increases in self-reported fear predicted blunted cortisol responses in men (β=0.41, p=.04). Also for men, longer durations of anger expression predicted exaggerated cortisol responses (β=0.67 p=.004), and more anger incidences predicted exaggerated cortisol and heart rate responses (β=0.51, p=.033; β=0.46, p=.066, resp.). Anger and fear did not predict SNS or HPA activity for females (all p>.23). The current differential self-report and facial coding findings support the use of multiple modes of emotion assessment. Particularly, FACS but not self-report revealed a robust anger-stress association that could have important downstream health effects for men. For women, future research may clarify the role of other emotions, such as self-conscious expressions of shame, for physiological stress responses. A better understanding of the emotion-stress link may contribute to behavioral interventions targeting health-promoting ways of

  9. STIFDB2: An Updated Version of Plant Stress-Responsive TranscrIption Factor DataBase with Additional Stress Signals, Stress-Responsive Transcription Factor Binding Sites and Stress-Responsive Genes in Arabidopsis and Rice

    OpenAIRE

    Naika, Mahantesha; Shameer, Khader; Mathew, Oommen K; Gowda, Ramanjini; Sowdhamini, Ramanathan

    2013-01-01

    Understanding the principles of abiotic and biotic stress responses, tolerance and adaptation remains important in plant physiology research to develop better varieties of crop plants. Better understanding of plant stress response mechanisms and application of knowledge derived from integrated experimental and bioinformatics approaches are gaining importance. Earlier, we showed that compiling a database of stress-responsive transcription factors and their corresponding target binding sites in...

  10. Context and strain-dependent behavioral response to stress

    Directory of Open Access Journals (Sweden)

    Baum Amber E

    2008-06-01

    Full Text Available Abstract Background This study posed the question whether strain differences in stress-reactivity lead to differential behavioral responses in two different tests of anxiety. Strain differences in anxiety-measures are known, but strain differences in the behavioral responses to acute prior stress are not well characterized. Methods We studied male Fisher 344 (F344 and Wistar Kyoto (WKY rats basally and immediately after one hour restraint stress. To distinguish between the effects of novelty and prior stress, we also investigated behavior after repeated exposure to the test chamber. Two behavioral tests were explored; the elevated plus maze (EPM and the open field (OFT, both of which are thought to measure activity, exploration and anxiety-like behaviors. Additionally, rearing, a voluntary behavior, and grooming, a relatively automatic, stress-responsive stereotyped behavior were measured in both tests. Results Prior exposure to the test environment increased anxiety-related measures regardless of prior stress, reflecting context-dependent learning process in both tests and strains. Activity decreased in response to repeated testing in both tests and both strains, but prior stress decreased activity only in the OFT which was reversed by repeated testing. Prior stress decreased anxiety-related measures in the EPM, only in F344s, while in the OFT, stress led to increased freezing mainly in WKYs. Conclusion Data suggest that differences in stressfulness of these tests predict the behavior of the two strains of animals according to their stress-reactivity and coping style, but that repeated testing can overcome some of these differences.

  11. Low-stress and high-stress singing have contrasting effects on glucocorticoid response

    Directory of Open Access Journals (Sweden)

    Daisy eFancourt

    2015-09-01

    Full Text Available Performing music in public is widely recognised as a potentially stress-inducing activity. However, despite the interest in music performance as an acute psychosocial stressor, there has been relatively little research on the effects of public performance on the endocrine system. This study examined the impact of singing in a low-stress performance situation and a high-stress live concert on levels of glucocorticoids (cortisol and cortisone in 15 professional singers. The results showed a significant decrease in both cortisol and cortisone across the low-stress condition, suggesting that singing in itself is a stress-reducing (and possibly health-promoting activity, but significant increases across the high-stress condition. This is the first study to demonstrate that singing affects glucocorticoid responses and that these responses are modulated by the conditions of performance.

  12. Recent Molecular Advances on Downstream Plant Responses to Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Cláudia Regina Batista de Souza

    2012-07-01

    Full Text Available Abiotic stresses such as extremes of temperature and pH, high salinity and drought, comprise some of the major factors causing extensive losses to crop production worldwide. Understanding how plants respond and adapt at cellular and molecular levels to continuous environmental changes is a pre-requisite for the generation of resistant or tolerant plants to abiotic stresses. In this review we aimed to present the recent advances on mechanisms of downstream plant responses to abiotic stresses and the use of stress-related genes in the development of genetically engineered crops.

  13. When does stress help or harm? The effects of stress controllability and subjective stress response on Stroop performance.

    Directory of Open Access Journals (Sweden)

    Roselinde Kaiser Henderson

    2012-06-01

    Full Text Available The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing to clinical therapy. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual’s response to stressors: moderate responses to stress can lead to improved performance while extreme (high or low responses can lead to impaired performance. The present studies tested the hypothesis that 1 learning to behaviorally control stressors leads to improved performance on a test of general executive functioning, the color-word Stroop, and that 2 this improvement emerges specifically for people who report moderate (subjective responses to stress. Experiment 1: Stroop performance, measured before and after a stress manipulation, was compared across groups of undergraduate participants (n=109. People who learned to control a noise stressor and received accurate performance feedback demonstrated reduced Stroop interference compared with people exposed to uncontrollable noise stress and feedback indicating an exaggerated rate of failure. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest reduction in Stroop interference. In contrast, in the group exposed to uncontrollable events, self-reported stress failed to predict performance. Experiment 2: In a second sample (n=90, we specifically investigated the role of controllability by keeping the rate of failure feedback constant across groups. In the group who learned behavioral control, those who reported moderate levels of stress

  14. Production of Polyamines Is Enhanced by Endogenous Abscisic Acid in Maize Seedlings Subjected to Salt Stress

    Institute of Scientific and Technical Information of China (English)

    Jun LIU; Ming-Yi JIANG; Yi-Feng ZHOU; You-Liang LIU

    2005-01-01

    It is known that salt stress and exogenously applied abscisic acid (ABA) can enhance the polyamine content in plants and that salt stress itself can lead to an increase in endogenous ABA production.In the present study, the relationships between salt-induced ABA and polyamine accumulation were investigated using ABA-deficient mutant (vp5/vp5) maize (Zea mays L.) seedlings and ABA and polyamine :biosynthesis inhibitors. The results show that reduced endogenous ABA levels, as a result of either the mutation or by using a chemical inhibitor (sodium tungstate), also reduced the accumulation of polyamines in salt-stressed leaves of maize seedlings. The polyamine synthesis inhibitors D-arginine and αdifluoromethylornithine also reduced the polyamine content of the leaves of maize seedling under salt stress. Both ABA and polyamine enhanced the dry weight accumulation of salt-stressed seedlings and also increased the activities of the two dominant tonoplast membrane enzymes, H+-ATPase and H+-PPase, when plants were under salt stress. The results suggest that salt stress induces an increase in endogenous ABA levels, which then enhances polyamine synthesis. Such responses may increase a plant's tolerance to salt.

  15. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu

    2014-11-21

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  16. Roles of Hsp70s in Stress Responses of Microorganisms, Plants, and Animals

    Directory of Open Access Journals (Sweden)

    Anmin Yu

    2015-01-01

    Full Text Available Hsp70s (heat shock protein 70s are a class of molecular chaperones that are highly conserved and ubiquitous in organisms ranging from microorganisms to plants and humans. Most research on Hsp70s has focused on the mechanisms of their functions as molecular chaperones, but recently, studies on stress responses are coming to the forefront. Hsp70s play key roles in cellular development and protecting living organisms from environmental stresses such as heat, drought, salinity, acidity, and cold. Moreover, functions of human Hsp70s are related to diseases including neurological disorders, cancer, and virus infection. In this review, we provide an overview of the specific roles of Hsp70s in response to stress, particularly abiotic stress, in all living organisms.

  17. Phosphatidic acid: a multifunctional stress-signalling lipid in plants.

    NARCIS (Netherlands)

    C. Testerink; T. Munnik

    2005-01-01

    Phosphatidic acid (PA) has only recently been identified as an important signaling molecule in both plants and animals. Nonetheless, it already promises to rival the importance of the classic second messengers Ca(2+) and cAMP. In plants, its formation is triggered in response to various biotic and a

  18. Modulation of immune responses in stress by Yoga

    Directory of Open Access Journals (Sweden)

    Arora Sarika

    2008-01-01

    Full Text Available Stress is a constant factor in today′s fastpaced life that can jeopardize our health if left unchecked. It is only in the last half century that the role of stress in every ailment from the common cold to AIDS has been emphasized, and the mechanisms involved in this process have been studied. Stress influences the immune response presumably through the activation of the hypothalamic-pituitary adrenal axis, hypothalamic pituitary-gonadal axis, and the sympathetic-adrenal-medullary system. Various neurotransmitters, neuropeptides, hormones, and cytokines mediate these complex bidirectional interactions between the central nervous system (CNS and the immune system. The effects of stress on the immune responses result in alterations in the number of immune cells and cytokine dysregulation. Various stress management strategies such as meditation, yoga, hypnosis, and muscle relaxation have been shown to reduce the psychological and physiological effects of stress in cancers and HIV infection. This review aims to discuss the effect of stress on the immune system and examine how relaxation techniques such as Yoga and meditation could regulate the cytokine levels and hence, the immune responses during stress.

  19. Sex differences in the stress response in SD rats.

    Science.gov (United States)

    Lu, Jing; Wu, Xue-Yan; Zhu, Qiong-Bin; Li, Jia; Shi, Li-Gen; Wu, Juan-Li; Zhang, Qi-Jun; Huang, Man-Li; Bao, Ai-Min

    2015-05-01

    Sex differences play an important role in depression, the basis of which is an excessive stress response. We aimed at revealing the neurobiological sex differences in the same study in acute- and chronically-stressed rats. Female Sprague-Dawley (SD) rats were randomly divided into 6 groups: chronic unpredictable mild stress (CUMS), acute foot shock (FS) and controls, animals in all 3 groups were sacrificed in proestrus or diestrus. Male SD rats were randomly divided into 3 groups: CUMS, FS and controls. Comparisons were made of behavioral changes in CUMS and control rats, plasma levels of corticosterone (CORT), testosterone (T) and estradiol (E2), and of the hypothalamic mRNA-expression of stress-related molecules, i.e. estrogen receptor α and β, androgen receptor, aromatase, mineralocorticoid receptor, glucocorticoid receptor, corticotropin-releasing hormone, arginine vasopressin and oxytocin. CUMS resulted in disordered estrus cycles, more behavioral and hypothalamic stress-related molecules changes and a stronger CORT response in female rats compared with male rats. Female rats also showed decreased E2 and T levels after FS and CUMS, while male FS rats showed increased E2 and male CUMS rats showed decreased T levels. Stress affects the behavioral, endocrine and the molecular response of the stress systems in the hypothalamus of SD rats in a clear sexual dimorphic way, which has parallels in human data on stress and depression. PMID:25687843

  20. Gpx3-dependent responses against oxidative stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kho, Chang Won; Lee, Phil Young; Bae, Kwang-Hee; Kang, Sunghyun; Cho, Sayeon; Lee, Do Hee; Sun, Choong-Hyun; Yi, Gwan-Su; Park, Byoung Chul; Park, Sung Goo

    2008-02-01

    The yeast Saccharomyces cerevisiae has defense mechanisms identical to higher eukaryotes. It offers the potential for genome-wide experimental approaches owing to its smaller genome size and the availability of the complete sequence. It therefore represents an ideal eukaryotic model for studying cellular redox control and oxidative stress responses. S. cerevisiae Yap1 is a well-known transcription factor that is required for H2O2-dependent stress responses. Yap1 is involved in various signaling pathways in an oxidative stress response. The Gpx3 (Orp1/PHGpx3) protein is one of the factors related to these signaling pathways. It plays the role of a transducer that transfers the hydroperoxide signal to Yap1. In this study, using extensive proteomic and bioinformatics analyses, the function of the Gpx3 protein in an adaptive response against oxidative stress was investigated in wild-type, gpx3-deletion mutant, and gpx3-deletion mutant overexpressing Gpx3 protein strains. We identified 30 proteins that are related to the Gpx3- dependent oxidative stress responses and 17 proteins that are changed in a Gpx3-dependent manner regardless of oxidative stress. As expected, H2O2-responsive Gpx3-dependent proteins include a number of antioxidants related with cell rescue and defense. In addition, they contain a variety of proteins related to energy and carbohydrate metabolism, transcription, and protein fate. Based upon the experimental results, it is suggested that Gpx3-dependent stress adaptive response includes the regulation of genes related to the capacity to detoxify oxidants and repair oxidative stress-induced damages affected by Yap1 as well as metabolism and protein fate independent from Yap1. PMID:18309271

  1. Expression Profiling of Abiotic Stress-Inducible Genes in response to Multiple Stresses in Rice (Oryza sativa L. Varieties with Contrasting Level of Stress Tolerance

    Directory of Open Access Journals (Sweden)

    Supratim Basu

    2014-01-01

    Full Text Available The present study considered transcriptional profiles and protein expression analyses from shoot and/or root tissues under three abiotic stress conditions, namely, salinity, dehydration, and cold, as well as following exogenous abscisic acid treatment, at different time points of stress exposure in three indica rice varieties, IR-29 (salt sensitive, Pokkali, and Nonabokra (both salt tolerant. The candidate genes chosen for expression studies were HKT-1, SOS-3, NHX-1, SAPK5, SAPK7, NAC-1, Rab16A, OSBZ8, DREBP2, CRT/DREBP, WRKY24, and WRKY71, along with the candidate proteins OSBZ8, SAMDC, and GST. Gene expression profile revealed considerable differences between the salt-sensitive and salt-tolerant rice varieties, as the expression in the latter was higher even at the constitutive level, whereas it was inducible only by corresponding stress signals in IR-29. Whether in roots or shoots, the transcriptional responses to different stressors peaked following 24 h of stress/ABA exposure, and the transcript levels enhanced gradually with the period of exposure. The generality of stress responses at the transcriptional level was therefore time dependent. Heat map data also showed differential transcript abundance in the three varieties, correlating the observation with transcript profiling. In silico analysis of the upstream regions of all the genes represented the existence of conserved sequence motifs in single or multiple copies that are indispensable to abiotic stress response. Overall, the transcriptome and proteome analysis undertaken in the present study indicated that genes/proteins conferring tolerance, belonging to different functional classes, were overrepresented, thus providing novel insight into the functional basis of multiple stress tolerance in indica rice varieties. The present work will pave the way in future to select gene(s for overexpression, so as to generate broad spectrum resistance to multiple stresses simultaneously.

  2. Arbuscular mycorrhizal fungal responses to abiotic stresses: A review.

    Science.gov (United States)

    Lenoir, Ingrid; Fontaine, Joël; Lounès-Hadj Sahraoui, Anissa

    2016-03-01

    The majority of plants live in close collaboration with a diversity of soil organisms among which arbuscular mycorrhizal fungi (AMF) play an essential role. Mycorrhizal symbioses contribute to plant growth and plant protection against various environmental stresses. Whereas the resistance mechanisms induced in mycorrhizal plants after exposure to abiotic stresses, such as drought, salinity and pollution, are well documented, the knowledge about the stress tolerance mechanisms implemented by the AMF themselves is limited. This review provides an overview of the impacts of various abiotic stresses (pollution, salinity, drought, extreme temperatures, CO2, calcareous, acidity) on biodiversity, abundance and development of AMF and examines the morphological, biochemical and molecular mechanisms implemented by AMF to survive in the presence of these stresses. PMID:26803396

  3. Genes Acting on Transcriptional Control during Abiotic Stress Responses

    Directory of Open Access Journals (Sweden)

    Glacy Jaqueline da Silva

    2014-01-01

    Full Text Available Abiotic stresses are the major cause of yield loss in crops around the world. Greater genetic gains are possible by combining the classical genetic improvement with advanced molecular biology techniques. The understanding of mechanisms triggered by plants to meet conditions of stress is of fundamental importance for the elucidation of these processes. Current genetically modified crops help to mitigate the effects of these stresses, increasing genetic gains in order to supply the agricultural market and the demand for better quality food throughout the world. To obtain safe genetic modified organisms for planting and consumption, a thorough grasp of the routes and genes that act in response to these stresses is necessary. This work was developed in order to collect important information about essential TF gene families for transcriptional control under abiotic stress responses.

  4. Fatty acids and oxidative stress in psychiatric disorders

    Directory of Open Access Journals (Sweden)

    Tonello Lucio

    2008-04-01

    Full Text Available Abstract Background The aim of this study was to determine whether there is published evidence for increased oxidative stress in neuropsychiatric disorders. Methods A PubMed search was carried out using the MeSH search term 'oxidative stress' in conjunction with each of the DSM-IV-TR diagnostic categories of the American Psychiatric Association in order to identify potential studies. Results There was published evidence of increased oxidative stress in the following DSM-IV-TR diagnostic categories: mental retardation; autistic disorder; Rett's disorder; attention-deficit hyperactivity disorder; delirium; dementia; amnestic disorders; alcohol-related disorders; amphetamine (or amphetamine-like-related disorders; hallucinogen-related disorders; nicotine-related disorders; opioid-related disorders; schizophrenia and other psychotic disorders; mood disorders; anxiety disorders; sexual dysfunctions; eating disorders; and sleep disorders. Conclusion Most psychiatric disorders are associated with increased oxidative stress. Patients suffering from that subgroup of these psychiatric disorders in which there is increased lipid peroxidation might therefore benefit from fatty acid supplementation (preferably with the inclusion of an antioxidant-rich diet while patients suffering from all these psychiatric disorders might benefit from a change to a whole-food plant-based diet devoid of refined carbohydrate products.

  5. The role of the HvNAC6 transcription factor in response to biotic and abiotic stress in barley

    DEFF Research Database (Denmark)

    Chen, Yan-Jun

    -mediated transformation methods could be used to study stress responses at the whole-plant level. The abscisic acid (ABA) and salicylic acid (SA) levels were measured during Bgh infection to investigate the involvement of these hormones and TF in the basal resistance. HvNAC6 RNAi plants were also subjected to dehydration...

  6. Crop and medicinal plants proteomics in response to salt stress

    Directory of Open Access Journals (Sweden)

    Keyvan eAghaei

    2013-01-01

    Full Text Available Increasing of world population marks a serious need to create new crop cultivars and medicinal plants with high growth and production at any environmental situations. Among the environmental unfavorable conditions, salinity is the most widespread in the world. Crop production and growth severely decreases under salt stress; however, some crop cultivars show significant tolerance against the negative effects of salinity. Among salt stress responses of crops, proteomic responses play a pivotal role in their ability to cope with it and have become the main center of notification. Many physiological responses are detectable in terms of protein increase and decrease even before physiological responses take place. Thus proteomic approach makes a short cut in the way of inferring how crops response to salt stress. Nowadays many salt-responsive proteins such as heat shock proteins, pathogen related proteins, protein kinases, ascorbate peroxidase, osmotin, ornithine decarboxylase and some transcription factors, have been detected in some major crops which are thought to give them the ability of withstanding against salt stress. Proteomic analysis of medicinal plants also revealed that alkaloid biosynthesis related proteins such as tryptophan synthase, codeinone reductase, strictosidine synthase and 12-oxophytodienoate reductase might have major role in production of secondary metabolites. In this review we are comparing some different or similar proteomic responses of several crops and medicinal plants to salt stress and discuss about the future prospects.

  7. Stressed out? Associations between perceived and physiological stress responses in adolescents : The TRAILS study

    NARCIS (Netherlands)

    Oldehinkel, Albertine J.; Ormel, Johan; Bosch, Nienke M.; Bouma, Esther M. C.; Van Roon, Arie M.; Rosmalen, Judith G. M.; Riese, Harriette

    2011-01-01

    Studies regarding the interrelation of perceived and physiological stress indices have shown diverging results. Using a population sample of adolescents (N=715, 50.9% girls, mean age 16.11 years, SD=0.59), we tested three hypotheses: (1) perceived responses during social stress covary with concurren

  8. Hemodynamic responses to mental stress during salt loading

    DEFF Research Database (Denmark)

    Gefke, Maria; Christensen, Niels Juel; Bech, Per;

    2016-01-01

    PURPOSE: The purpose was to examine whether prolonged moderate stress associated with a student exam would increase the blood pressure response to a salt load in young healthy normotensive individuals. METHODS: Ten healthy young subjects were examined at two different occasions in random order (i......) during preparation for a medical exam (prolonged stress) and (ii) outside the exam period (low stress). All subjects consumed a controlled diet for 3 days with low- or high-salt content in randomized order. The subjective stress was measured by Spielberger's State-Trait Anxiety Inventory-Scale, SCL...... Symptom Checklist for stress and the Visual Analogue Scale. On each level of stress, 24-h ambulatory blood pressure and cardiac output (CO) were measured. Furthermore, plasma norepinephrine (NE), epinephrine (E) and plasma renin activity (PRA) were measured. RESULTS: Twenty-four-hour ABP, 24-h heart rate...

  9. Plant Responses to Simultaneous Biotic and Abiotic Stress: Molecular Mechanisms

    Directory of Open Access Journals (Sweden)

    Ines Ben Rejeb

    2014-10-01

    Full Text Available Plants are constantly confronted to both abiotic and biotic stresses that seriously reduce their productivity. Plant responses to these stresses are complex and involve numerous physiological, molecular, and cellular adaptations. Recent evidence shows that a combination of abiotic and biotic stress can have a positive effect on plant performance by reducing the susceptibility to biotic stress. Such an interaction between both types of stress points to a crosstalk between their respective signaling pathways. This crosstalk may be synergistic and/or antagonistic and include among others the involvement of phytohormones, transcription factors, kinase cascades, and reactive oxygen species (ROS. In certain cases, such crosstalk can lead to a cross-tolerance and enhancement of a plant’s resistance against pathogens. This review aims at giving an insight into cross-tolerance between abiotic and biotic stress, focusing on the molecular level and regulatory pathways.

  10. Comparison of Proteome Response to Saline and Zinc Stress in Lettuce

    Directory of Open Access Journals (Sweden)

    Luigi eLucini

    2015-04-01

    Full Text Available Zinc salts occurring in soils can exert an osmotic stress toward plants. However, being zinc a heavy metal, some more specific effects on plant metabolisms can be forecast. In this work, lettuce has been used as a model to investigate salt and zinc stresses at proteome level through a shotgun tandem MS proteomic approach. The effect of zinc stress in lettuce, in comparison with NaCl stress, was evaluated to dissect between osmotic/oxidative stress-related effects, from those changes specifically related to zinc.The analysis of proteins exhibiting a fold change of 3 as minimum (on log 2 normalized abundances, revealed the involvement of photosynthesis (via stimulation of chlorophyll synthesis and enhanced role of photosystem I as well as stimulation of photophosphorylation. Increased glycolytic supply of energy substrates and ammonium assimilation (through formation of glutamine synthetase were also induced by zinc in soil. Similarly, protein metabolism (at both transcriptional and ribosomal level, heat shock proteins and proteolysis were affected. According to their biosynthetic enzymes, hormones appear to be altered by both the treatment and the time point considered: ethylene biosynthesis was enhanced, while production of abscisic acid was up-regulated at the earlier time point to decrease markedly and gibberellins were decreased at the later one.Besides aquaporin PIP2 synthesis, other osmotic/oxidative stress related compounds were enhanced under zinc stress, i.e. proline, hydroxycinnamic acids, ascorbate, sesquiterpene lactones and terpenoids biosynthesis.Although the proteins involved in the response to zinc stress and to salinity were substantially the same, their abundance changed between the two treatments. Lettuce response to zinc was more prominent at the first sampling point, yet showing a faster adaptation than under NaCl stress. Indeed, lettuce plants showed an adaptation after 30 days of stress, in a more pronounced way in the case

  11. Plant transcriptomics and responses to environmental stress: an overview

    Indian Academy of Sciences (India)

    Sameen Ruqia Imadi; Alvina Gul Kazi; Mohammad Abass Ahanger; Salih Gucel; Parvaiz Ahmad

    2015-09-01

    Different stresses include nutrient deficiency, pathogen attack, exposure to toxic chemicals etc. Transcriptomic studies have been mainly applied to only a few plant species including the model plant, Arabidopsis thaliana. These studies have provided valuable insights into the genetic networks of plant stress responses. Transcriptomics applied to cash crops including barley, rice, sugarcane, wheat and maize have further helped in understanding physiological and molecular responses in terms of genome sequence, gene regulation, gene differentiation, posttranscriptional modifications and gene splicing. On the other hand, comparative transcriptomics has provided more information about plant’s response to diverse stresses. Thus, transcriptomics, together with other biotechnological approaches helps in development of stress tolerance in crops against the climate change.

  12. Exogenous salicylic acid protects phospholipids against cadmium stress in flax (Linum usitatissimum L.).

    Science.gov (United States)

    Belkadhi, Aïcha; De Haro, Antonio; Obregon, Sara; Chaïbi, Wided; Djebali, Wahbi

    2015-10-01

    Salicylic acid (SA) promotes plant defense responses against toxic metal stresses. The present study addressed the hypothesis that 8-h SA pretreatment, would alter membrane lipids in a way that would protect against Cd toxicity. Flax seeds were pre-soaked for 8h in SA (0, 250 and 1000µM) and then subjected, at seedling stage, to cadmium (Cd) stress. At 100µM CdCl2, significant decreases in the percentages of phosphatidylcholine (PC), phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and monogalactosyldiacylglycerol (MGDG) and changes in their relative fatty acid composition were observed in Cd-treated roots in comparison with controls. However, in roots of 8-h SA pretreated plantlets, results showed that the amounts of PC and PE were significantly higher as compared to non-pretreated plantlets. Additionally, in both lipid classes, the proportion of linolenic acid (18:3) increased upon the pretreatment with SA. This resulted in a significant increase in the fatty acid unsaturation ratio of the root PC and PE classes. As the exogenous application of SA was found to be protective of flax lipid metabolism, the possible mechanisms of protection against Cd stress in flax roots were discussed.

  13. the response of plants to drought stress

    Directory of Open Access Journals (Sweden)

    Rys Magdalena

    2015-08-01

    a wider spectrum of compounds scattering the radiation in the leaves tested, and their subsequent comparative analysis. The impact of drought on metabolism of soybean was clearly visible on spectra and confirmed using cluster analysis. The technical problem of the influence of leaf water content on measurements, which appeared in studies, will be discussed. To conclude, FT-Raman spectroscopy may be a good complement to other non-invasive methods, e.g., fluorescent methods, in assessing the stress-induced damage of crops.

  14. Involvement of endoplasmic reticulum stress response in orofacial inflammatory pain.

    Science.gov (United States)

    Yang, Eun Sun; Bae, Jin Young; Kim, Tae Heon; Kim, Yun Sook; Suk, Kyoungho; Bae, Yong Chul

    2014-12-01

    Endoplasmic reticulum (ER) stress is involved in many neurological diseases and inflammatory responses. Inflammatory mediators induce neuronal damage and trigger the neuropathic or inflammatory pain. But there is very little data on the role of the ER stress response in pain mechanisms. In this study, we explored whether the ER stress response is involved in orofacial inflammatory pain by using a complete Freund's adjuvant (CFA)-injected rat model. The thermal pain hypersensitivity increased significantly after CFA injection. We found that the protein and mRNA levels of ER stress response genes, GRP78/Bip and p-eIF2α, increased significantly in trigeminal ganglion (TG) of CFA-injected rats compared to control animals. In immunofluorescence analysis, a significant increase of GRP78 and p-eIF2α immunopositive neurons was observed in CFA-injected TG compared to control TG. When we administered an ER stress modulator, salubrinal, CFA-induced thermal pain hypersensitivity was temporally reduced. Thus, our study suggests that ER stress responses in TG neurons contribute to CFA-induced inflammatory pain, and may comprise an important molecular mechanism underlying the orofacial inflammatory pain pathway. PMID:25548537

  15. Chloroplast Retrograde Regulation of Heat Stress Responses in Plants.

    Science.gov (United States)

    Sun, Ai-Zhen; Guo, Fang-Qing

    2016-01-01

    It is well known that intracellular signaling from chloroplast to nucleus plays a vital role in stress responses to survive environmental perturbations. The chloroplasts were proposed as sensors to heat stress since components of the photosynthetic apparatus housed in the chloroplast are the major targets of thermal damage in plants. Thus, communicating subcellular perturbations to the nucleus is critical during exposure to extreme environmental conditions such as heat stress. By coordinating expression of stress specific nuclear genes essential for adaptive responses to hostile environment, plants optimize different cell functions and activate acclimation responses through retrograde signaling pathways. The efficient communication between plastids and the nucleus is highly required for such diverse metabolic and biosynthetic functions during adaptation processes to environmental stresses. In recent years, several putative retrograde signals released from plastids that regulate nuclear genes have been identified and signaling pathways have been proposed. In this review, we provide an update on retrograde signals derived from tetrapyrroles, carotenoids, reactive oxygen species (ROS) and organellar gene expression (OGE) in the context of heat stress responses and address their roles in retrograde regulation of heat-responsive gene expression, systemic acquired acclimation, and cellular coordination in plants. PMID:27066042

  16. Contrasting urban and rural heat stress responses to climate change

    Science.gov (United States)

    Fischer, E. M.; Oleson, K. W.; Lawrence, D. M.

    2012-02-01

    Hot temperatures in combination with high humidity cause human discomfort and may increase morbidity and mortality. A global climate model with an embedded urban model is used to explore the urban-rural contrast in the wet-bulb globe temperature, a heat stress index accounting for temperature and humidity. Wet-bulb globe temperatures are calculated at each model time step to resolve the heat stress diurnal cycle. The model simulates substantially higher heat stress in urban areas compared to neighbouring rural areas. Urban humidity deficit only weakly offsets the enhanced heat stress due to the large night-time urban heat island. The urban-rural contrast in heat stress is most pronounced at night and over mid-latitudes and subtropics. During heatwaves, the urban heat stress amplification is particularly pronounced. Heat stress strongly increases with doubled CO2 concentrations over both urban and rural surfaces. The tropics experience the greatest increase in number of high-heat-stress nights, despite a relatively weak ˜2°C warming. Given the lack of a distinct annual cycle and high relative humidity, the modest tropical warming leads to exceedance of the present-day record levels during more than half of the year in tropical regions, where adaptive capacity is often low. While the absolute urban and rural heat stress response to 2 × CO2 is similar, the occurrence of nights with extremely high heat stress increases more in cities than surrounding rural areas.

  17. Transcriptome Sequencing in Response to Salicylic Acid in Salvia miltiorrhiza.

    Science.gov (United States)

    Zhang, Xiaoru; Dong, Juane; Liu, Hailong; Wang, Jiao; Qi, Yuexin; Liang, Zongsuo

    2016-01-01

    Salvia miltiorrhiza is a traditional Chinese herbal medicine, whose quality and yield are often affected by diseases and environmental stresses during its growing season. Salicylic acid (SA) plays a significant role in plants responding to biotic and abiotic stresses, but the involved regulatory factors and their signaling mechanisms are largely unknown. In order to identify the genes involved in SA signaling, the RNA sequencing (RNA-seq) strategy was employed to evaluate the transcriptional profiles in S. miltiorrhiza cell cultures. A total of 50,778 unigenes were assembled, in which 5,316 unigenes were differentially expressed among 0-, 2-, and 8-h SA induction. The up-regulated genes were mainly involved in stimulus response and multi-organism process. A core set of candidate novel genes coding SA signaling component proteins was identified. Many transcription factors (e.g., WRKY, bHLH and GRAS) and genes involved in hormone signal transduction were differentially expressed in response to SA induction. Detailed analysis revealed that genes associated with defense signaling, such as antioxidant system genes, cytochrome P450s and ATP-binding cassette transporters, were significantly overexpressed, which can be used as genetic tools to investigate disease resistance. Our transcriptome analysis will help understand SA signaling and its mechanism of defense systems in S. miltiorrhiza. PMID:26808150

  18. Response to osmotic stress and temperature of the fungus Ustilago maydis.

    Science.gov (United States)

    Salmerón-Santiago, Karina Gabriela; Pardo, Juan Pablo; Flores-Herrera, Oscar; Mendoza-Hernández, Guillermo; Miranda-Arango, Manuel; Guerra-Sánchez, Guadalupe

    2011-10-01

    Ustilago maydis is a fungal pathogen which is exposed during its life cycle to both abiotic and biotic stresses before and after the infection of maize. To cope with extreme environmental changes, microorganisms usually accumulate the disaccharide trehalose. We have investigated both the accumulation of trehalose and the activity of trehalase during the adaptation of U. maydis haploid cells to thermal, sorbitol, and NaCl stresses. Sorbitol and sodium chloride induced sustained accumulation of trehalose, while a transient increase was observed under heat stress. Sorbitol stressed cells showed higher trehalase activity compared with control cells and to those stressed by NaCl and high temperature. Addition of cycloheximide, a protein synthesis inhibitor, did not affect the trehalose accumulation during the first 15 min, but basal levels of trehalose were reached after the second period of 15 min. The proteomic analysis of the response of U. maydis to temperature, sorbitol, and salt stresses indicated a complex pattern which highlights the change of 18 proteins involved in carbohydrate and amino acid metabolism, protein folding, redox regulation, ion homeostasis, and stress response. We hypothesize that trehalose accumulation during sorbitol stress in U. maydis might be related to the adaptation of this organism during plant infection.

  19. Molecular and biochemical responses of Volvox carteri to oxidative stress

    Science.gov (United States)

    Lingappa, U.; Rankin-Gee, E. K.; Lera, M.; Bebour, B.; Marcu, O.

    2014-03-01

    Understanding the intracellular response to environmental stresses is a key aspect to understanding the limits of habitability for life as we know it. A wide range of relevant stressors, from heat shock to radiation, result in the intracellular production of reactive oxygen species (ROS). ROS are used physiologically as signaling molecules to cause changes in gene expression and metabolism. However, ROS, including superoxide (O2-) and peroxides, are also highly reactive molecules that cause oxidative damage to proteins, lipids and DNA. Here we studied stress response in the multicellular, eukaryotic green alga Volvox carteri, after exposure to heat shock conditions. We show that the ROS response to heat stress is paralleled by changes in photosynthetic metabolism, antioxidant enzyme activity and gene expression, and fluctuations in the elemental composition of cells. Metabolism, as measured by pulse amplitude modulated (PAM) fluorometry over two hours of heat stress, showed a linear decrease in the photosynthetic efficiency of Volvox. ROS quantification uncovered an increase in ROS in the culture medium, paralleled by a decrease in ROS within the Volvox colonies, suggesting an export mechanism is utilized to mitigate stress. Enzyme kinetics indicated an increase in superoxide dismutase (SOD) activity over the heat stress timecourse. Using X-ray fluorescence (XRF) at the Stanford Synchrotron Radiation Lightsource, we show that these changes coincide with cell-specific import/export and intracellular redistribution of transition elements and halides, suggesting that the cellular metallome is also engaged in mediating oxidative stress in Volvox.

  20. Mechanistic insights into aging, cell cycle progression, and stress response

    Directory of Open Access Journals (Sweden)

    Troy Anthony Alan Harkness

    2012-06-01

    Full Text Available The longevity of an organism depends on the health of its cells. Throughout life cells are exposed to numerous intrinsic and extrinsic stresses, such as free radicals, generated through mitochondrial electron transport, and ultraviolet irradiation. The cell has evolved numerous mechanisms to scavenge free radicals and repair damage induced by these insults. One mechanism employed by the yeast Saccharomyces cerevisiae to combat stress utilizes the Anaphase Promoting Complex (APC, an essential multi-subunit ubiquitin-protein ligase structurally and functionally conserved from yeast to humans that controls progression through mitosis and G1. We have observed that yeast cells expressing compromised APC subunits are sensitive to multiple stresses and have shorter replicative and chronological lifespans. In a pathway that runs parallel to that regulated by the APC, members of the Forkhead box (Fox transcription factor family also regulate stress responses. The yeast Fox orthologues Fkh1 and Fkh2 appear to drive the transcription of stress response factors and slow early G1 progression, while the APC seems to regulate chromatin structure, chromosome segregation, and resetting of the transcriptome in early G1. In contrast, under non-stress conditions, the Fkhs play a complex role in cell cycle progression, partially through activation of the APC. Direct and indirect interactions between the APC and the yeast Fkhs appear to be pivotal for lifespan determination. Here we explore the potential for these interactions to be evolutionarily conserved as a mechanism to balance cell cycle regulation with stress responses.

  1. Gene Response to Salt Stress in Populus euphratica

    Institute of Scientific and Technical Information of China (English)

    Shen Xin; Thomas Teichmenn; Wang Yiqin; Bai Genben; Yu Guangjun; Wang Shasheng

    2003-01-01

    Through construction of a subtracted cDNA library and library screening, a number of salt-induced cDNA fragmentshave been cloned from Populus euphratica. Based on the results of DNA sequencing and Northern analysis, the gene response ofPopulus euphratica to salt stress is discussed. It is indicated that in response to salt treatment the transcription level for some genes ofPopulus euphratica increases by about 1.5 times and significant difference between the responses to osmotic stress and to ion stresshas been observed in gene activity.

  2. Integrated quantitative analysis of nitrogen stress response in Chlamydomonas reinhardtii using metabolite and protein profiling.

    Science.gov (United States)

    Wase, Nishikant; Black, Paul N; Stanley, Bruce A; DiRusso, Concetta C

    2014-03-01

    Nitrogen starvation induces a global stress response in microalgae that results in the accumulation of lipids as a potential source of biofuel. Using GC-MS-based metabolite and iTRAQ-labeled protein profiling, we examined and correlated the metabolic and proteomic response of Chlamydomonas reinhardtii under nitrogen stress. Key amino acids and metabolites involved in nitrogen sparing pathways, methyl group transfer reactions, and energy production were decreased in abundance, whereas certain fatty acids, citric acid, methionine, citramalic acid, triethanolamine, nicotianamine, trehalose, and sorbitol were increased in abundance. Proteins involved in nitrogen assimilation, amino acid metabolism, oxidative phosphorylation, glycolysis, TCA cycle, starch, and lipid metabolism were elevated compared with nonstressed cultures. In contrast, the enzymes of the glyoxylate cycle, one carbon metabolism, pentose phosphate pathway, the Calvin cycle, photosynthetic and light harvesting complex, and ribosomes were reduced. A noteworthy observation was that citrate accumulated during nitrogen stress coordinate with alterations in the enzymes that produce or utilize this metabolite, demonstrating the value of comparing protein and metabolite profiles to understand complex patterns of metabolic flow. Thus, the current study provides unique insight into the global metabolic adjustments leading to lipid storage during N starvation for application toward advanced biofuel production technologies.

  3. Keratins Are Altered in Intestinal Disease-Related Stress Responses

    Science.gov (United States)

    Helenius, Terhi O.; Antman, Cecilia A.; Asghar, Muhammad Nadeem; Nyström, Joel H.; Toivola, Diana M.

    2016-01-01

    Keratin (K) intermediate filaments can be divided into type I/type II proteins, which form obligate heteropolymers. Epithelial cells express type I-type II keratin pairs, and K7, K8 (type II) and K18, K19 and K20 (type I) are the primary keratins found in the single-layered intestinal epithelium. Keratins are upregulated during stress in liver, pancreas, lung, kidney and skin, however, little is known about their dynamics in the intestinal stress response. Here, keratin mRNA, protein and phosphorylation levels were studied in response to murine colonic stresses modeling human conditions, and in colorectal cancer HT29 cells. Dextran sulphate sodium (DSS)-colitis was used as a model for intestinal inflammatory stress, which elicited a strong upregulation and widened crypt distribution of K7 and K20. K8 levels were slightly downregulated in acute DSS, while stress-responsive K8 serine-74 phosphorylation (K8 pS74) was increased. By eliminating colonic microflora using antibiotics, K8 pS74 in proliferating cells was significantly increased, together with an upregulation of K8 and K19. In the aging mouse colon, most colonic keratins were upregulated. In vitro, K8, K19 and K8 pS74 levels were increased in response to lipopolysaccharide (LPS)-induced inflammation in HT29 cells. In conclusion, intestinal keratins are differentially and dynamically upregulated and post-translationally modified during stress and recovery. PMID:27626448

  4. Keratins Are Altered in Intestinal Disease-Related Stress Responses.

    Science.gov (United States)

    Helenius, Terhi O; Antman, Cecilia A; Asghar, Muhammad Nadeem; Nyström, Joel H; Toivola, Diana M

    2016-01-01

    Keratin (K) intermediate filaments can be divided into type I/type II proteins, which form obligate heteropolymers. Epithelial cells express type I-type II keratin pairs, and K7, K8 (type II) and K18, K19 and K20 (type I) are the primary keratins found in the single-layered intestinal epithelium. Keratins are upregulated during stress in liver, pancreas, lung, kidney and skin, however, little is known about their dynamics in the intestinal stress response. Here, keratin mRNA, protein and phosphorylation levels were studied in response to murine colonic stresses modeling human conditions, and in colorectal cancer HT29 cells. Dextran sulphate sodium (DSS)-colitis was used as a model for intestinal inflammatory stress, which elicited a strong upregulation and widened crypt distribution of K7 and K20. K8 levels were slightly downregulated in acute DSS, while stress-responsive K8 serine-74 phosphorylation (K8 pS74) was increased. By eliminating colonic microflora using antibiotics, K8 pS74 in proliferating cells was significantly increased, together with an upregulation of K8 and K19. In the aging mouse colon, most colonic keratins were upregulated. In vitro, K8, K19 and K8 pS74 levels were increased in response to lipopolysaccharide (LPS)-induced inflammation in HT29 cells. In conclusion, intestinal keratins are differentially and dynamically upregulated and post-translationally modified during stress and recovery. PMID:27626448

  5. Effects of oxidative stress on fatty acid- and one-carbon-metabolism in psychiatric and cardiovascular disease comorbidity

    OpenAIRE

    Assies, J.; Mocking, R J T; Lok, A; Ruhé, H.G.; Pouwer, F.; Schene, A. H.

    2014-01-01

    Objective Cardiovascular disease (CVD) is the leading cause of death in severe psychiatric disorders (depression, schizophrenia). Here, we provide evidence of how the effects of oxidative stress on fatty acid (FA) and one-carbon (1-C) cycle metabolism, which may initially represent adaptive responses, might underlie comorbidity between CVD and psychiatric disorders. Method We conducted a literature search and integrated data in a narrative review. Results Oxidative stress, mainly generated in...

  6. Oxidative stress impairs the heat stress response and delays unfolded protein recovery.

    Directory of Open Access Journals (Sweden)

    Masaaki Adachi

    Full Text Available BACKGROUND: Environmental changes, air pollution and ozone depletion are increasing oxidative stress, and global warming threatens health by heat stress. We now face a high risk of simultaneous exposure to heat and oxidative stress. However, there have been few studies investigating their combined adverse effects on cell viability. PRINCIPAL FINDINGS: Pretreatment of hydrogen peroxide (H(2O(2 specifically and highly sensitized cells to heat stress, and enhanced loss of mitochondrial membrane potential. H(2O(2 exposure impaired the HSP40/HSP70 induction as heat shock response (HSR and the unfolded protein recovery, and enhanced eIF2alpha phosphorylation and/or XBP1 splicing, land marks of ER stress. These H(2O(2-mediated effects mimicked enhanced heat sensitivity in HSF1 knockdown or knockout cells. Importantly, thermal preconditioning blocked H(2O(2-mediated inhibitory effects on refolding activity and rescued HSF1 +/+ MEFs, but neither blocked the effects nor rescued HSF1 -/- MEFs. These data strongly suggest that inhibition of HSR and refolding activity is crucial for H(2O(2-mediated enhanced heat sensitivity. CONCLUSIONS: H(2O(2 blocks HSR and refolding activity under heat stress, thereby leading to insufficient quality control and enhancing ER stress. These uncontrolled stress responses may enhance cell death. Our data thus highlight oxidative stress as a crucial factor affecting heat tolerance.

  7. Bacillus cereus cell response upon exposure to acid environment: towards the identification of potential biomarkers

    Directory of Open Access Journals (Sweden)

    Noémie eDESRIAC

    2013-10-01

    Full Text Available Microorganisms are able to adapt to different environments and evolve rapidly, allowing them to cope with their new environments. Such adaptive response and associated protections towards other lethal stresses, is a crucial survival strategy for a wide spectrum of microorganisms, including food spoilage bacteria, pathogens and organisms used in functional food applications. The growing demand for minimal processed food yields to an increasing use of combination of hurdles or mild preservation factors in the food industry. A commonly used hurdle is low pH which allows the decrease in bacterial growth rate but also the inactivation of pathogens or spoilage microorganisms. Bacillus cereus is a well-known food-borne pathogen leading to economical and safety issues in food industry. Because survival mechanisms implemented will allow bacteria to cope with environmental changes, it is important to provide understanding of B. cereus stress response. Thus this review deals with the adaptive traits of B. cereus cells facing to acid stress conditions. The acid stress response of B. cereus could be divided into four groups (i general stress response (ii pH homeostasis, (iii metabolic modifications and alkali production and (iv secondary oxidative stress response. This current knowledge may be useful to understand how B. cereus cells may cope to acid environment such as encountered in food products and thus to find some molecular biomarkers of the bacterial behaviour. These biomarkers could be furthermore used to develop new microbial behaviour prediction tools which can provide insights into underlying molecular physiological states which govern the behaviour of microorganisms and thus opening the avenue toward the detection of stress adaptive behaviour at an early stage and the control of stress-induced resistance throughout the food chain.

  8. Responses of marine plankton to pollutant stress

    DEFF Research Database (Denmark)

    Hjorth, M.

    The thesis analyses effects of pollutants on natural plankton communities on the basis of three independent mesocosm experiments and a series of laboratory experiments performed in Denmark and Greenland. The work focus on integrating functional and structural measures of community responses to...

  9. Yokukansan inhibits neuronal death during ER stress by regulating the unfolded protein response.

    Directory of Open Access Journals (Sweden)

    Toru Hiratsuka

    Full Text Available BACKGROUND: Recently, several studies have reported Yokukansan (Tsumura TJ-54, a traditional Japanese medicine, as a potential new drug for the treatment of Alzheimer's disease (AD. Endoplasmic reticulum (ER stress is known to play an important role in the pathogenesis of AD, particularly in neuronal death. Therefore, we examined the effect of Yokukansan on ER stress-induced neurotoxicity and on familial AD-linked presenilin-1 mutation-associated cell death. METHODS: We employed the WST-1 assay and monitored morphological changes to evaluate cell viability following Yokukansan treatment or treatment with its components. Western blotting and PCR were used to observe the expression levels of GRP78/BiP, caspase-4 and C/EBP homologous protein. RESULTS: Yokukansan inhibited neuronal death during ER stress, with Cnidii Rhizoma (Senkyu, a component of Yokukansan, being particularly effective. We also showed that Yokukansan and Senkyu affect the unfolded protein response following ER stress and that these drugs inhibit the activation of caspase-4, resulting in the inhibition of ER stress-induced neuronal death. Furthermore, we found that the protective effect of Yokukansan and Senkyu against ER stress could be attributed to the ferulic acid content of these two drugs. CONCLUSIONS: Our results indicate that Yokukansan, Senkyu and ferulic acid are protective against ER stress-induced neuronal cell death and may provide a possible new treatment for AD.

  10. Apoplastic reactive oxygen species transiently decrease auxin signaling and cause stress-induced morphogenic response in Arabidopsis.

    Science.gov (United States)

    Blomster, Tiina; Salojärvi, Jarkko; Sipari, Nina; Brosché, Mikael; Ahlfors, Reetta; Keinänen, Markku; Overmyer, Kirk; Kangasjärvi, Jaakko

    2011-12-01

    Reactive oxygen species (ROS) are ubiquitous signaling molecules in plant stress and development. To gain further insight into the plant transcriptional response to apoplastic ROS, the phytotoxic atmospheric pollutant ozone was used as a model ROS inducer in Arabidopsis (Arabidopsis thaliana) and gene expression was analyzed with microarrays. In contrast to the increase in signaling via the stress hormones salicylic acid, abscisic acid, jasmonic acid (JA), and ethylene, ROS treatment caused auxin signaling to be transiently suppressed, which was confirmed with a DR5-uidA auxin reporter construct. Transcriptomic data revealed that various aspects of auxin homeostasis and signaling were modified by apoplastic ROS. Furthermore, a detailed analysis of auxin signaling showed that transcripts of several auxin receptors and Auxin/Indole-3-Acetic Acid (Aux/IAA) transcriptional repressors were reduced in response to apoplastic ROS. The ROS-derived changes in the expression of auxin signaling genes partially overlapped with abiotic stress, pathogen responses, and salicylic acid signaling. Several mechanisms known to suppress auxin signaling during biotic stress were excluded, indicating that ROS regulated auxin responses via a novel mechanism. Using mutants defective in various auxin (axr1, nit1, aux1, tir1 afb2, iaa28-1, iaa28-2) and JA (axr1, coi1-16) responses, ROS-induced cell death was found to be regulated by JA but not by auxin. Chronic ROS treatment resulted in altered leaf morphology, a stress response known as "stress-induced morphogenic response." Altered leaf shape of tir1 afb2 suggests that auxin was a negative regulator of stress-induced morphogenic response in the rosette.

  11. Metabolomics to Detect Response of Lettuce (Lactuca sativa) to Cu(OH)2 Nanopesticides: Oxidative Stress Response and Detoxification Mechanisms.

    Science.gov (United States)

    Zhao, Lijuan; Ortiz, Cruz; Adeleye, Adeyemi S; Hu, Qirui; Zhou, Hongjun; Huang, Yuxiong; Keller, Arturo A

    2016-09-01

    There has been an increasing influx of nanopesticides into agriculture in recent years. Understanding the interaction between nanopesticides and edible plants is crucial in evaluating the potential impact of nanotechnology on the environment and agriculture. Here we exposed lettuce plants to Cu(OH)2 nanopesticides (1050-2100 mg/L) through foliar spray for one month. Inductively coupled plasma-mass spectrometry (ICP-MS) results indicate that 97-99% (1353-2501 mg/kg) of copper was sequestered in the leaves and only a small percentage (1-3%) (17.5-56.9 mg/kg) was translocated to root tissues through phloem loading. Gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS) based metabolomics combined with partial least squares-discriminant analysis (PLS-DA) multivariate analysis revealed that Cu(OH)2 nanopesticides altered metabolite levels of lettuce leaves. Tricarboxylic (TCA) cycle and a number of amino acid-related biological pathways were disturbed. Some antioxidant levels (cis-caffeic acid, chlorogenic acid, 3,4-dihydroxycinnamic acid, dehydroascorbic acid) were significantly decreased compared to the control, indicating that oxidative stress and a defense response occurred. Nicotianamine, a copper chelator, increased by 12-27 fold compared to the control, which may represent a detoxification mechanism. The up-regulation of polyamines (spermidine and putrescine) and potassium may mitigate oxidative stress and enhance tolerance. The data presented here provide a molecular-scale perspective on the response of plants to copper nanopesticides. PMID:27483188

  12. Individual differences in cortisol stress response predict increases in voice pitch during exam stress.

    Science.gov (United States)

    Pisanski, Katarzyna; Nowak, Judyta; Sorokowski, Piotr

    2016-09-01

    Despite a long history of empirical research, the potential vocal markers of stress remain unclear. Previous studies examining speech under stress most consistently report an increase in voice pitch (the acoustic correlate of fundamental frequency, F0), however numerous studies have failed to replicate this finding. In the present study we tested the prediction that these inconsistencies are tied to variation in the severity of the stress response, wherein voice changes may be observed predominantly among individuals who show a cortisol stress response (i.e., an increase in free cortisol levels) above a critical threshold. Voice recordings and saliva samples were collected from university psychology students at baseline and again immediately prior to an oral examination. Voice recordings included both read and spontaneous speech, from which we measured mean, minimum, maximum, and the standard deviation in F0. We observed an increase in mean and minimum F0 under stress in both read and spontaneous speech, whereas maximum F0 and its standard deviation showed no systematic changes under stress. Our results confirmed that free cortisol levels increased by an average of 74% (ranging from 0 to 270%) under stress. Critically, increases in cortisol concentrations significantly predicted increases in mean F0 under stress for both speech types, but did not predict variation in F0 at baseline. On average, stress-induced increases in voice pitch occurred only when free cortisol levels more than doubled their baseline concentrations. Our results suggest that researchers examining speech under stress should control for individual differences in the magnitude of the stress response. PMID:27188981

  13. Abscisic Acid Catabolism in Maize Kernels in Response to Water Deficit at Early Endosperm Development

    OpenAIRE

    Wang, Zhaolong; MAMBELLI, STEFANIA; SETTER, TIM L.

    2002-01-01

    To further our understanding of the greater susceptibility of apical kernels in maize inflorescences to water stress, abscisic acid (ABA) catabolism activity was evaluated in developing kernels with chirally separated (+)‐[3H]ABA. The predominant pathway of ABA catabolism was via 8′‐hydroxylase to form phaseic acid, while conjugation to glucose was minor. In response to water deficit imposed on whole plants during kernel development, ABA accumulated to higher concentrations in apical than bas...

  14. Chloroplast retrograde regulation of heat stress responses in plants

    Directory of Open Access Journals (Sweden)

    Ai-Zhen eSun

    2016-03-01

    Full Text Available It is well known that intracellular signaling from chloroplast to nucleus plays a vital role in stress responses to survive environmental perturbations. The chloroplasts were proposed as sensors to heat stress since components of the photosynthetic apparatus housed in the chloroplast are the primary susceptible targets of thermal damage in plants. Thus, communicating subcellular perturbations to the nucleus is critical during exposure to extreme environmental conditions such as heat stress. By coordinating expression of stress specific nuclear genes essential for adaptive responses to hostile environment, plants optimize different cell functions and activate acclimation responses through retrograde signaling pathways. Such diverse metabolic and biosynthetic functions require efficient communication between plastids and the nucleus. In recent years several putative retrograde signals released from plastids that regulate nuclear genes have been identified and signaling pathways have been proposed. In this review, we provide an update on retrograde signals derived from tetrapyrroles, carotenoids, reactive oxygen species (ROS and organellar gene expression (OGE in the context of heat stress responses and address their roles in retrograde regulation of heat-responsive gene expression, systemic acquired acclimation and cellular coordination in plants.

  15. Physiological roles of plastid terminal oxidase in plant stress responses

    Indian Academy of Sciences (India)

    Xin Sun; Tao Wen

    2011-12-01

    The plastid terminal oxidase (PTOX) is a plastoquinol oxidase localized in the plastids of plants. It is able to transfer electrons from plastoquinone (PQ) to molecular oxygen with the formation of water. Recent studies have suggested that PTOX is beneficial for plants under environmental stresses, since it is involved in the synthesis of photoprotective carotenoids and chlororespiration, which could potentially protect the chloroplast electron transport chain (ETC) from over-reduction. The absence of PTOX in plants usually results in photo-bleached variegated leaves and impaired adaptation to environment alteration. Although PTOX level and activity has been found to increase under a wide range of stress conditions, the functions of plant PTOX in stress responses are still disputed now. In this paper, the possible physiological roles of PTOX in plant stress responses are discussed based on the recent progress.

  16. Dynamic modeling of cellular response to DNA damage based on p53 stress response networks

    Institute of Scientific and Technical Information of China (English)

    Jinpeng Qi; Yongsheng Ding; Shihuang Shao

    2009-01-01

    Under acute perturbations from the outside, cells can trigger self-defensive mechanisms to fight against genome stress. To investigate the cellular response to continuous ion radiation (IR), a dynamic model for p53 stress response networks at the cellular level is proposed. The model can successfully be used to simulate the dynamic processes of double-strand breaks (DSBs) generation and their repair, switch-like ataxia telangiectasia mutated (ATM) activation, oscillations occurring in the p53-MDM2 feedback loop, as well as toxins elimination triggered by p53 stress response networks. Especially, the model can predict the plausible outcomes of cellular response under different IR dose regimes.

  17. Time course transcriptome changes in Shewanella algae in response to salt stress.

    Directory of Open Access Journals (Sweden)

    Xiuping Fu

    Full Text Available Shewanella algae, which produces tetrodotoxin and exists in various seafoods, can cause human diseases, such as spondylodiscitis and bloody diarrhea. In the present study, we focused on the temporal, dynamic process in salt-stressed S. algae by monitoring the gene transcript levels at different time points after high salt exposure. Transcript changes in amino acid metabolism, carbohydrate metabolism, energy metabolism, membrane transport, regulatory functions, and cellular signaling were found to be important for the high salt response in S. algae. The most common strategies used by bacteria to survive and grow in high salt environments, such as Na+ efflux, K+ uptake, glutamate transport and biosynthesis, and the accumulation of compatible solutes, were also observed in S. algae. In particular, genes involved in peptidoglycan biosynthesis and DNA repair were highly and steadily up-regulated, accompanied by rapid and instantaneous enhancement of the transcription of large- and small-ribosome subunits, which suggested that the structural changes in the cell wall and some stressful responses occurred in S. algae. Furthermore, the transcription of genes involved in the tricarboxylic acid (TCA cycle and the glycolytic pathway was decreased, whereas the transcription of genes involved in anaerobic respiration was increased. These results, demonstrating the multi-pathway reactions of S. algae in response to salt stress, increase our understanding of the microbial stress response mechanisms.

  18. Acid adaptation induces cross-protection against environmental stresses in Salmonella typhimurium.

    OpenAIRE

    Leyer, G J; Johnson, E A

    1993-01-01

    The relationship of acid adaptation to tolerance of other environmental stresses was examined in Salmonella typhimurium. S. typhimurium was adapted to acid by exposing the cells to mildly acidic conditions (pH 5.8) for one to two cell doublings. Acid-adapted cells were found to have increased tolerance towards various stresses including heat, salt, an activated lactoperoxidase system, and the surface-active agents crystal violet and polymyxin B. Acid adaptation increased cell surface hydropho...

  19. Swim stress differentially blocks CRF receptor mediated responses in dorsal raphe nucleus.

    Science.gov (United States)

    Lamy, Christophe M; Beck, Sheryl G

    2010-10-01

    Modulation of the serotonergic (5-HT) neurotransmitter system arising from the dorsal raphe nucleus (DR) is thought to support the behavioral effects of swim stress, i.e., immobility. In vivo pharmacological and anatomical studies suggest that corticotropin-releasing factor (CRF) and γ-aminobutyric acid (GABA) synaptic transmission closely interact to set the response of the DR to swim stress. To investigate the cellular basis of these physiological mechanisms the effects of ovine CRF (oCRF) on GABA(A)-dependent miniature inhibitory postsynaptic currents (mIPSCs) in 5-HT and non-5-HT DR neurons in acute mesencephalic slices obtained from rats either naïve or 24h after a 15 min swim stress session were tested. In this study, the effect of swim stress alone was to decrease the holding current, i.e., hyperpolarize the neuron, and to increase the amplitude and charge of mIPSCs recorded from non-5-HT neurons. Ovine CRF (10 nM) induced an increase in mIPSC frequency in 5-HT neurons recorded from naïve rats, an effect that was suppressed by swim stress. The inward current elicited by oCRF in both 5-HT and non-5-HT neurons was also blocked by swim stress. Ovine CRF increased mIPSCs amplitude and charge in both 5-HT and non-5-HT neurons, but this effect was not modified by swim stress. In concert with our previous findings that swim stress decreased input resistance, action potential threshold and action potential duration and increased glutamatergic synaptic activity the overall primary effect of swim stress is to increase the excitability of 5-HT neurons. These data provide a mechanism at the cellular level for the immobility induced by swim stress and identifies critical components of the raphe circuitry responsible for the altered output of 5-HT neurons induced by swim stress.

  20. Identification of Drought-Responsive Universal Stress Proteins in Viridiplantae

    OpenAIRE

    Isokpehi, Raphael D.; Simmons, Shaneka S.; Cohly, Hari H. P.; Ekunwe, Stephen I.N.; Begonia, Gregorio B.; Ayensu, Wellington K.

    2011-01-01

    Genes encoding proteins that contain the universal stress protein (USP) domain are known to provide bacteria, archaea, fungi, protozoa, and plants with the ability to respond to a plethora of environmental stresses. Specifically in plants, drought tolerance is a desirable phenotype. However, limited focused and organized functional genomic datasets exist on drought-responsive plant USP genes to facilitate their characterization. The overall objective of the investigation was to identify diver...

  1. Historical Temperature Variability Affects Coral Response to Heat Stress

    OpenAIRE

    Jessica Carilli; Donner, Simon D.; Hartmann, Aaron C.

    2012-01-01

    Coral bleaching is the breakdown of symbiosis between coral animal hosts and their dinoflagellate algae symbionts in response to environmental stress. On large spatial scales, heat stress is the most common factor causing bleaching, which is predicted to increase in frequency and severity as the climate warms. There is evidence that the temperature threshold at which bleaching occurs varies with local environmental conditions and background climate conditions. We investigated the influence of...

  2. Mutation as a Stress Response and the Regulation of Evolvability

    OpenAIRE

    Galhardo, Rodrigo S.; Hastings, P. J.; Rosenberg, Susan M.

    2007-01-01

    Our concept of a stable genome is evolving to one in which genomes are plastic and responsive to environmental changes. Growing evidence shows that a variety of environmental stresses induce genomic instability in bacteria, yeast, and human cancer cells, generating occasional fitter mutants and potentially accelerating adaptive evolution. The emerging molecular mechanisms of stress-induced mutagenesis vary but share telling common components that underscore two common themes. The first is the...

  3. Erythropoietin Action in Stress Response, Tissue Maintenance and Metabolism

    OpenAIRE

    Yuanyuan Zhang; Li Wang; Soumyadeep Dey; Mawadda Alnaeeli; Sukanya Suresh; Heather Rogers; Ruifeng Teng; Constance Tom Noguchi

    2014-01-01

    Erythropoietin (EPO) regulation of red blood cell production and its induction at reduced oxygen tension provides for the important erythropoietic response to ischemic stress. The cloning and production of recombinant human EPO has led to its clinical use in patients with anemia for two and half decades and has facilitated studies of EPO action. Reports of animal and cell models of ischemic stress in vitro and injury suggest potential EPO benefit beyond red blood cell production including vas...

  4. Empathy and stress related neural responses in maternal decision making

    OpenAIRE

    Ho, S. Shaun; Konrath, Sara; Brown, Stephanie; Swain, James E.

    2014-01-01

    Mothers need to make caregiving decisions to meet the needs of children, which may or may not result in positive child feedback. Variations in caregivers' emotional reactivity to unpleasant child-feedback may be partially explained by their dispositional empathy levels. Furthermore, empathic response to the child's unpleasant feedback likely helps mothers to regulate their own stress. We investigated the relationship between maternal dispositional empathy, stress reactivity, and neural correl...

  5. Empathy and Stress Related Neural Responses in Maternal Decision Making

    OpenAIRE

    SaraKonrath; StephanieBrown; JamesESwain

    2014-01-01

    Mothers need to make caregiving decisions to meet the needs of children, which may or may not result in positive child feedback. Variations in caregivers’ emotional reactivity to unpleasant child-feedback may be partially explained by their dispositional empathy levels. Furthermore, empathic response to the child’s unpleasant feedback likely helps mothers to regulate their own stress. We investigated the relationship between maternal dispositional empathy, stress reactivity, and neural corre...

  6. Forearm vascular responses to mental stress in healthy older adults

    OpenAIRE

    Heffernan, Matthew J.; Patel, Hardikkumar M.; Muller, Matthew D.

    2013-01-01

    Abstract Forearm vascular conductance (FVC) increases in response to mental stress (verbal mental arithmetic) in young people. However, the effect of healthy aging and mental stress on FVC is unknown. In this study, we tested the hypothesis that FVC and cutaneous vascular conductance (CVC) would be attenuated in older adults compared to young adults. In 13 young (27 ± 1 year) and 11 older (62 ± 1 year) subjects, we quantified heart rate (HR), mean arterial pressure (MAP), FVC (Doppler ultraso...

  7. Response of Serum Prolactin to Thermal Stress During Water Immersion

    OpenAIRE

    Matsumoto, Takaaki; Kosaka, Mitsuo; Yamauchi, Masaki; Nakamura, Koichi; Yamashita, Shunichi; Izumi, Motomori; Nagataki, Shigenobu

    1988-01-01

    Physiological action of prolactin is not well-known in human except those concerning pregnancy and lactation. Elevated serum prolactin level due to various stresses such as heat load, physical exercise, surgery, gastroscopy has been reported. In order to elucidate the response of serum prolactin to thermal stress, preliminary experiments were done in a male subject. Three different thermal stimuli were applied by head-out water immersion (water temperature: 28.5, 34 and 40℃, respectively) for...

  8. Stress response and mode of ventilation in preterm infants

    OpenAIRE

    Quinn, M.; de Boer, R C; Ansari, N.; Baumer, J

    1998-01-01

    AIM—To assess the change in stress response in preterm babies changed from patient triggered ventilation (PTV) to conventional mandatory ventilation (CMV) and vice versa; to determine outcome in relation to stress hormone concentrations.
METHODS—A randomised controlled study was conducted in two district general hospital neonatal intensive care units. Thirty babies, treated initially with CMV, were randomly assigned to remain on CMV or to change to PTV. A second group of 29 ...

  9. Stress, Roles and Responsibilities of Single Mothers in Malaysia

    OpenAIRE

    Mohd Hashim Intan Hashimah; Azmawati Azman Azwan; Endut Noraida

    2015-01-01

    Life as a single mother is often associated with great demands and many challenges. This study examines how a group of single mothers in Malaysia views sources of stress and challenges in their lives. It also investigates perceived roles and responsibilities of single mothers. Three hundred single mothers from all over Malaysia were interviewed in this study. Single mothers reported relatively low level of stress that was mostly related to financial (insufficient pay) and day-to-day living. T...

  10. The behavioural effects of predator-induced stress responses in the cricket (Gryllus texensis): the upside of the stress response.

    Science.gov (United States)

    Adamo, Shelley A; Kovalko, Ilya; Mosher, Brianna

    2013-12-15

    Predator-induced stress responses are thought to reduce an animal's risk of being eaten. Therefore, these stress responses should enhance anti-predator behaviour. We found that individual insects (the cricket Gryllus texensis) show reliable behavioural responses (i.e. behavioural types) in a plus-shaped maze. An individual's behaviour in the plus maze remained consistent for at least 1/2 of its adult life. However, after exposure to a model predator, both male and female crickets showed a reduced period of immobility and an increased amount of time spent under shelter compared with controls. These changes could be mimicked by injections of the insect stress neurohormone octopamine. These behavioural changes probably aid crickets in evading predators. Exposure to a model predator increased the ability of crickets to escape a live predator (a bearded dragon, Pogona vitticeps). An injection of octopamine had the same effect, showing that stress hormones can reduce predation. Using crickets to study the fitness consequences of predator-induced stress responses will help integrate ecological and biomedical concepts of 'stress'. PMID:24307711

  11. Neonatal handling alters maternal emotional response to stress.

    Science.gov (United States)

    Reis, Adolfo R; Jacobs, Silvana; Menegotto, Pâmela R; Silveira, Patrícia P; Lucion, Aldo B

    2016-07-01

    Neonatal handling is an experimental procedure used to analyze the effects of environmental interventions during early postpartum days (PPD). Long-lasting effects of repeated stress exposure in the neonatal period on the maternal side are poorly studied in this model. The aim of this study was to verify if handling the pups induces enduring effects on damśstress responses, increasing their risk for depression. Dams were divided into two groups (NH-Non-handled and H-Handled) based on the handling procedure (pups were handled for 1 min/per day from PPD1-PPD10) and then subdivided into four groups (NH, NH + S, H, and H + S) based on the exposure or not to restraint stress after weaning (1 hr/per day for 7 days, PPD22-PPD28). We analyzed damśbehavior in the forced swimming test (FST PPD29-PPD30), plasma basal corticosterone and BDNF levels, as well as adrenal weight (PPD31). The results show that handling alters the stress response of dams to acute and chronic stress, as evidenced by dams of the H group having increased immobility in the first day of FST (p handling may induce a long-lasting effect on maternal stress response; these changes in the damśemotional reactivity increase their susceptibility for the development of psychiatric disorders such as depression. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58: 614-622, 2016. PMID:27020142

  12. Transcriptomic responses to heat stress and bleaching in the elkhorn coral Acropora palmata

    KAUST Repository

    DeSalvo, MK

    2010-03-08

    The emergence of genomic tools for reef-building corals and symbiotic anemones comes at a time when alarming losses in coral cover are being observed worldwide. These tools hold great promise in elucidating novel and unforeseen cellular processes underlying the successful mutualism between corals and their dinoflagellate endosymbionts Symbiodinium spp. Since thermal stress triggers a breakdown in the symbiosis (coral bleaching), measuring the transcriptomic response to thermal stress-induced bleaching offers an extraordinary view of cellular processes that are specific to coral–algal symbioses. In the present study, we utilized a cDNA microarray containing 2059 genes of the threatened Caribbean elkhorn coral Acropora palmata to identify genes that are differentially expressed upon thermal stress. Fragments from replicate colonies were exposed to elevated temperature for 2 d, and samples were frozen for microarray analysis after 24 and 48 h. Totals of 204 and 104 genes were differentially expressed in samples that were collected 1 and 2 d after thermal stress, respectively. Analysis of the differentially expressed genes indicates a cellular stress response in A. palmata involving (1) growth arrest, (2) chaperone activity, (3) nucleic acid stabilization and repair, and (4) removal of damaged macromolecules. Other differentially expressed processes include sensory perception, metabolite transfer between host and endosymbiont, nitric oxide signaling, and modifications to the actin cytoskeleton and extracellular matrix. The results are compared with those from a previous coral microarray study of thermal stress in Montastraea faveolata, and point to an overall evolutionary conserved bleaching response in scleractinian corals.

  13. Stress responses in alfalfa (Medicago sativa L. )

    Energy Technology Data Exchange (ETDEWEB)

    Kessmann, H.; Edwards, R.; Dixon, R.A. (Samuel Roberts Noble Foundation, Ardmore, OK (USA)); Geno, P.W. (Oklahoma State Univ., Stillwater (USA))

    1990-09-01

    The isoflavonoid conjugates medicarpin-3-O-glucoside-6{double prime}-O-malonate (MGM), afrormosin-7-O-glucoside (AG), and afrormosin-7-O-glucoside-6{double prime}-O-malonate (AGM) were isolated and characterized from cell suspension cultures of alfalfa (Medicago sativa L.), where they were the major constitutive secondary metabolites. They were also found in alfalfa roots but not in other parts of the plant. The phytoalexin medicarpin accumulated rapidly in suspension cultured cells treated with elicitor from Colletotrichum lindemuthianum, and this was subsequently accompanied by an increase in the levels of MGM. In contrast, net accumulation of afrormosin conjugates was not affected by elicitor treatment. Labeling studies with ({sup 14}C)phenylalanine indicated that afrormosin conjugates were the major de novo synthesized isoflavonoid products in unelicited cells. During elicitation, ({sup 14}C)phenylalanine was incorporated predominantly into medicarpin, although a significant proportion of the newly synthesized medicarpin was also conjugated. Treatment of {sup 14}C-labeled, elicited cells with L-{alpha}-aminooxy-{beta}-phenylpropionic acid, a potent inhibitor of PAL activity in vivo, resulted in the initial appearance of labeled medicarpin of very low specific activity, suggesting that the phytoalexin could be released from a preformed conjugate under these conditions. Our data draw attention to the involvement of isoflavone hydroxylases during the constitutive and elicitor-induced accumulation of isoflavonoids and their conjugates in alfalfa cell cultures.

  14. Stress responses in alfalfa (Medicago sativa L.)

    International Nuclear Information System (INIS)

    The isoflavonoid conjugates medicarpin-3-O-glucoside-6 double-prime-O-malonate (MGM), afrormosin-7-O-glucoside (AG), and afrormosin-7-O-glucoside-6 double-prime-O-malonate (AGM) were isolated and characterized from cell suspension cultures of alfalfa (Medicago sativa L.), where they were the major constitutive secondary metabolites. They were also found in alfalfa roots but not in other parts of the plant. The phytoalexin medicarpin accumulated rapidly in suspension cultured cells treated with elicitor from Colletotrichum lindemuthianum, and this was subsequently accompanied by an increase in the levels of MGM. In contrast, net accumulation of afrormosin conjugates was not affected by elicitor treatment. Labeling studies with [14C]phenylalanine indicated that afrormosin conjugates were the major de novo synthesized isoflavonoid products in unelicited cells. During elicitation, [14C]phenylalanine was incorporated predominantly into medicarpin, although a significant proportion of the newly synthesized medicarpin was also conjugated. Treatment of 14C-labeled, elicited cells with L-α-aminooxy-β-phenylpropionic acid, a potent inhibitor of PAL activity in vivo, resulted in the initial appearance of labeled medicarpin of very low specific activity, suggesting that the phytoalexin could be released from a preformed conjugate under these conditions. Our data draw attention to the involvement of isoflavone hydroxylases during the constitutive and elicitor-induced accumulation of isoflavonoids and their conjugates in alfalfa cell cultures

  15. Pharmacological modification of the perioperative stress response in noncardiac surgery.

    Science.gov (United States)

    Priebe, Hans-Joachim

    2016-06-01

    The perioperative period is associated with alterations in the neuroendocrine, metabolic, and immune systems, referred to as "stress response." The resultant increased sympathetic activity and elevated serum concentrations of catecholamines may adversely affect the cardiovascular system, resulting in cardiovascular instability (hypertension, tachycardia, and arrhythmia), morbidity (myocardial ischemia, myocardial infarction, and stroke), and mortality (cardiac death and fatal stroke), particularly in patients at an elevated cardiovascular risk and with reduced cardiovascular reserve. Various strategies have been used to ameliorate the adverse perioperative cardiovascular sequelae of the perioperative stress response. Effective pharmacologic blunting of the stress response plays a crucial role in perioperative cardiac risk reduction strategies. In this context, the role of beta-adrenoceptor blockers, alpha2-adrenoceptor agonists, and statins has been extensively examined. This chapter evaluates the available evidence with respect to treatment efficacy of these commonly prescribed drugs in patients undergoing noncardiac surgery. PMID:27396805

  16. Orientational Polarizability and Stress Response of Biological Cells

    Science.gov (United States)

    Safran, S. A.; de, R.; Zemel, A.

    We present a theoretical treatment of the orientational response to external stress of active, contractile cells embedded in a gel-like elastic medium. The theory includes random forces as well as forces that arise from the deformation of the matrix and those due to the internal regulation of the stress fibers and focal adhesions of the cell. We calculate both the static and high frequency limits of the orientational response in terms of the cellular polarizability. For systems in which the forces due to regulation and activity dominate the mechanical forces, we show that there is a non-linear dynamical response which, in the high frequency limit, causes the cell to orient nearly perpendicular to the direction of the applied stress.

  17. Lipid Biosynthesis Coordinates a Mitochondrial-to-Cytosolic Stress Response.

    Science.gov (United States)

    Kim, Hyun-Eui; Grant, Ana Rodrigues; Simic, Milos S; Kohnz, Rebecca A; Nomura, Daniel K; Durieux, Jenni; Riera, Celine E; Sanchez, Melissa; Kapernick, Erik; Wolff, Suzanne; Dillin, Andrew

    2016-09-01

    Defects in mitochondrial metabolism have been increasingly linked with age-onset protein-misfolding diseases such as Alzheimer's, Parkinson's, and Huntington's. In response to protein-folding stress, compartment-specific unfolded protein responses (UPRs) within the ER, mitochondria, and cytosol work in parallel to ensure cellular protein homeostasis. While perturbation of individual compartments can make other compartments more susceptible to protein stress, the cellular conditions that trigger cross-communication between the individual UPRs remain poorly understood. We have uncovered a conserved, robust mechanism linking mitochondrial protein homeostasis and the cytosolic folding environment through changes in lipid homeostasis. Metabolic restructuring caused by mitochondrial stress or small-molecule activators trigger changes in gene expression coordinated uniquely by both the mitochondrial and cytosolic UPRs, protecting the cell from disease-associated proteins. Our data suggest an intricate and unique system of communication between UPRs in response to metabolic changes that could unveil new targets for diseases of protein misfolding. PMID:27610574

  18. Abscisic acid regulates root growth under osmotic stress conditions via an interacting hormonal network with cytokinin, ethylene and auxin.

    Science.gov (United States)

    Rowe, James H; Topping, Jennifer F; Liu, Junli; Lindsey, Keith

    2016-07-01

    Understanding the mechanisms regulating root development under drought conditions is an important question for plant biology and world agriculture. We examine the effect of osmotic stress on abscisic acid (ABA), cytokinin and ethylene responses and how they mediate auxin transport, distribution and root growth through effects on PIN proteins. We integrate experimental data to construct hormonal crosstalk networks to formulate a systems view of root growth regulation by multiple hormones. Experimental analysis shows: that ABA-dependent and ABA-independent stress responses increase under osmotic stress, but cytokinin responses are only slightly reduced; inhibition of root growth under osmotic stress does not require ethylene signalling, but auxin can rescue root growth and meristem size; osmotic stress modulates auxin transporter levels and localization, reducing root auxin concentrations; PIN1 levels are reduced under stress in an ABA-dependent manner, overriding ethylene effects; and the interplay among ABA, ethylene, cytokinin and auxin is tissue-specific, as evidenced by differential responses of PIN1 and PIN2 to osmotic stress. Combining experimental analysis with network construction reveals that ABA regulates root growth under osmotic stress conditions via an interacting hormonal network with cytokinin, ethylene and auxin. PMID:26889752

  19. Transcriptional responses of Arabidopsis thaliana plants to As (V stress

    Directory of Open Access Journals (Sweden)

    Yuan Joshua S

    2008-08-01

    Full Text Available Abstract Background Arsenic is toxic to plants and a common environmental pollutant. There is a strong chemical similarity between arsenate [As (V] and phosphate (Pi. Whole genome oligonucleotide microarrays were employed to investigate the transcriptional responses of Arabidopsis thaliana plants to As (V stress. Results Antioxidant-related genes (i.e. coding for superoxide dismutases and peroxidases play prominent roles in response to arsenate. The microarray experiment revealed induction of chloroplast Cu/Zn superoxide dismutase (SOD (at2g28190, Cu/Zn SOD (at1g08830, as well as an SOD copper chaperone (at1g12520. On the other hand, Fe SODs were strongly repressed in response to As (V stress. Non-parametric rank product statistics were used to detect differentially expressed genes. Arsenate stress resulted in the repression of numerous genes known to be induced by phosphate starvation. These observations were confirmed with qRT-PCR and SOD activity assays. Conclusion Microarray data suggest that As (V induces genes involved in response to oxidative stress and represses transcription of genes induced by phosphate starvation. This study implicates As (V as a phosphate mimic in the cell by repressing genes normally induced when available phosphate is scarce. Most importantly, these data reveal that arsenate stress affects the expression of several genes with little or unknown biological functions, thereby providing new putative gene targets for future research.

  20. Stress for invasion success? Temperature stress of preceding generations modifies the response to insecticide stress in an invasive pest insect.

    Science.gov (United States)

    Piiroinen, Saija; Lyytinen, Anne; Lindström, Leena

    2013-02-01

    Adaptation to stressful environments is one important factor influencing species invasion success. Tolerance to one stress may be complicated by exposure to other stressors experienced by the preceding generations. We studied whether parental temperature stress affects tolerance to insecticide in the invasive Colorado potato beetle Leptinotarsa decemlineata. Field-collected pyrethroid-resistant beetles were reared under either stressful (17°C) or favourable (23°C) insecticide-free environments for three generations. Then, larvae were exposed to pyrethroid insecticides in common garden conditions (23°C). Beetles were in general tolerant to stress. The parental temperature stress alone affected beetles positively (increased adult weight) but it impaired their tolerance to insecticide exposure. In contrast, offspring from the favourable temperature regime showed compensatory weight gain in response to insecticide exposure. Our study emphasizes the potential of cross-generational effects modifying species stress tolerance. When resistant pest populations invade benign environments, a re-application of insecticides may enhance their performance via hormetic effects. In turn, opposite effects may arise if parental generations have been exposed to temperature stress. Thus, the outcome of management practices of invasive pest species is difficult to predict unless we also incorporate knowledge of the evolutionary and recent (preceding generations) stress history of the given populations into pest management. PMID:23467574

  1. Formaldehyde stress responses in bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Nathan Houqian Chen

    2016-03-01

    Full Text Available Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those dependent upon glutathione. The more prevalent thiol-dependent formaldehyde detoxification system is found in many bacterial pathogens, almost all of which do not metabolize methane or methanol. This review describes the endogenous and exogenous sources of formaldehyde, its toxic effects and mechanisms of detoxification. The methods of formaldehyde sensing are also described with a focus on the formaldehyde responsive transcription factors HxlR, FrmR and NmlR. Finally, the physiological relevance of detoxification systems for formaldehyde in bacterial pathogens is discussed.

  2. Formaldehyde Stress Responses in Bacterial Pathogens.

    Science.gov (United States)

    Chen, Nathan H; Djoko, Karrera Y; Veyrier, Frédéric J; McEwan, Alastair G

    2016-01-01

    Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those dependent upon glutathione. The more prevalent thiol-dependent formaldehyde detoxification system is found in many bacterial pathogens, almost all of which do not metabolize methane or methanol. This review describes the endogenous and exogenous sources of formaldehyde, its toxic effects and mechanisms of detoxification. The methods of formaldehyde sensing are also described with a focus on the formaldehyde responsive transcription factors HxlR, FrmR, and NmlR. Finally, the physiological relevance of detoxification systems for formaldehyde in bacterial pathogens is discussed. PMID:26973631

  3. Eccentric-exercise induced inflammation attenuates the vascular responses to mental stress

    NARCIS (Netherlands)

    N.J. Paine; C. Ring; S. Aldred; J.A. Bosch; A.J. Wadley; J.J.C.S. Veldhuijzen van Zanten

    2013-01-01

    Mental stress has been identified as a trigger of myocardial infarction (MI), with inflammation and vascular responses to mental stress independently implicated as contributing factors. This study examined whether inflammation moderates the vascular responses to mental stress. Eighteen healthy male

  4. Stretching the stress boundary: Linking air pollution health effects to a neurohormonal stress response.

    Science.gov (United States)

    Kodavanti, Urmila P

    2016-12-01

    Inhaled pollutants produce effects in virtually all organ systems in our body and have been linked to chronic diseases including hypertension, atherosclerosis, Alzheimer's and diabetes. A neurohormonal stress response (referred to here as a systemic response produced by activation of the sympathetic nervous system and hypothalamus-pituitary-adrenal (HPA)-axis) has been implicated in a variety of psychological and physical stresses, which involves immune and metabolic homeostatic mechanisms affecting all organs in the body. In this review, we provide new evidence for the involvement of this well-characterized neurohormonal stress response in mediating systemic and pulmonary effects of a prototypic air pollutant - ozone. A plethora of systemic metabolic and immune effects are induced in animals exposed to inhaled pollutants, which could result from increased circulating stress hormones. The release of adrenal-derived stress hormones in response to ozone exposure not only mediates systemic immune and metabolic responses, but by doing so, also modulates pulmonary injury and inflammation. With recurring pollutant exposures, these effects can contribute to multi-organ chronic conditions associated with air pollution. This review will cover, 1) the potential mechanisms by which air pollutants can initiate the relay of signals from respiratory tract to brain through trigeminal and vagus nerves, and activate stress responsive regions including hypothalamus; and 2) the contribution of sympathetic and HPA-axis activation in mediating systemic homeostatic metabolic and immune effects of ozone in various organs. The potential contribution of chronic environmental stress in cardiovascular, neurological, reproductive and metabolic diseases, and the knowledge gaps are also discussed. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu.

  5. A 2-Cys peroxiredoxin in response to oxidative stress in the pine wood nematode, Bursaphelenchus xylophilus

    OpenAIRE

    Zhen Li; Qingwen Zhang; Xuguo Zhou

    2016-01-01

    The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease that has devastated pine forests in Asia. Parasitic nematodes are known to have evolved antioxidant stress responses that defend against host plant defenses. In this study, the infestation of whitebark pine, Pinus bungean, with B. xylophilus led to a significant increase in plant hydrogen peroxide (H2O2) and salicylic acid levels. Correspondingly, the expression of an antioxidative enzyme, 2-Cysteine ...

  6. Response to stress in Drosophila is mediated by gender, age and stress paradigm.

    Science.gov (United States)

    Neckameyer, Wendi S; Nieto-Romero, Andres R

    2015-01-01

    All living organisms must maintain equilibrium in response to internal and external challenges within their environment. Changes in neural plasticity (alterations in neuronal populations, dendritic remodeling, and synaptic turnover) are critical components of the homeostatic response to stress, which has been strongly implicated in the onset of affective disorders. However, stress is differentially perceived depending on the type of stress and its context, as well as genetic background, age and sex; therefore, an individual's maintenance of neuronal homeostasis must differ depending upon these variables. We established Drosophila as a model to analyze homeostatic responses to stress. Sexually immature and mature females and males from an isogenic wild-type strain raised under controlled environmental conditions were exposed to four reproducible and high-throughput translatable stressors to facilitate the analysis of a large number of animals for direct comparisons. These animals were assessed in an open-field arena, in a light-dark box, and in a forced swim test, as well as for sensitivity to the sedative effects of ethanol. These studies establish that immature and mature females and males represent behaviorally distinct populations under control conditions as well as after exposure to different stressors. Therefore, the neural substrates mediating the stress response must be differentially expressed depending upon the hormonal status of the brain. In addition, an adaptive response to a given stressor in one paradigm was not predictive for outcomes in other paradigms.

  7. Stress effects on mood, HPA axis, and autonomic response: comparison of three psychosocial stress paradigms.

    Science.gov (United States)

    Giles, Grace E; Mahoney, Caroline R; Brunyé, Tad T; Taylor, Holly A; Kanarek, Robin B

    2014-01-01

    Extensive experimental psychology research has attempted to parse the complex relationship between psychosocial stress, mood, cognitive performance, and physiological changes. To do so, it is necessary to have effective, validated methods to experimentally induce psychosocial stress. The Trier Social Stress Test (TSST) is the most commonly used method of experimentally inducing psychosocial stress, but it is resource intensive. Less resource intense psychosocial stress tasks include the Socially Evaluative Cold Pressor Task (SECPT) and a computerized mental arithmetic task (MAT). These tasks effectively produce a physiological and psychological stress response and have the benefits of requiring fewer experimenters and affording data collection from multiple participants simultaneously. The objective of this study was to compare the magnitude and duration of these three experimental psychosocial stress induction paradigms. On each of four separate days, participants completed either a control non-stressful task or one of the three experimental stressors: the TSST, SECPT, or MAT. We measured mood, working memory performance, salivary cortisol and alpha-amylase (AA), and heart rate. The TSST and SECPT exerted the most robust effects on mood and physiological measures. TSST effects were generally evident immediately post-stress as well as 10- and 20-minutes after stress cessation, whereas SECPT effects were generally limited to the duration of the stressor. The stress duration is a key determinant when planning a study that utilizes an experimental stressor, as researchers may be interested in collecting dependent measures prior to stress cessation. In this way, the TSST would allow the investigator a longer window to administer tasks of interest.

  8. Inhibiting influence of testosterone on stress responsiveness during adolescence.

    Science.gov (United States)

    Lürzel, Stephanie; Kaiser, Sylvia; Krüger, Christine; Sachser, Norbert

    2011-11-01

    The maturation of the hypothalamo-pituitary-adrenal (HPA) axis is a key-component of the changes that occur during adolescence. In guinea pigs, HPA responsiveness during late adolescence depends strongly on the quantity and quality of social interactions: Males that lived in a large mixed-sex colony over the course of adolescence exhibit a lower stress response than males that were kept in pairs (one male/one female). Since colony-housed males have higher testosterone (T) levels than pair-housed males, and inhibiting effects of T on HPA function are well known, we tested the hypothesis that the decrease in stress responsiveness found in colony-housed males is due to their high T concentrations. We manipulated T levels in two experiments: 1) gonadectomy/sham-gonadectomy of colony-housed males (which usually have high T levels), 2) application of T undecanoate/vehicle to pair-housed males (which usually have low T levels). As expected, gonadectomized males showed a significantly increased stress response in comparison with sham-gonadectomized males, and T-injected males had a significantly lower stress response than vehicle-injected males. Both experiments thus confirm an inhibiting effect of T on HPA responsiveness during adolescence, which can mediate the influence of social interactions. The reduction in stress responsiveness is hypothesized to have a biologically adaptive value: A sudden increase in glucocorticoid concentrations can enhance aggressive behavior. Thus, pair-housed males might be adapted to aggressively defend their female ('resource defense strategy'), whereas colony-housed males display little aggressive behavior and are capable of integrating themselves into a colony ('queuing strategy'). PMID:21983230

  9. Stress response of brown pelican nestlings to ectoparasite infestation

    Science.gov (United States)

    Eggert, L.M.F.; Jodice, P.G.R.; O'Reilly, K. M.

    2010-01-01

    Measurement of corticosterone has become a useful tool for assessing the response of individuals to ecological stressors of interest. Enhanced corticosterone levels can promote survival of stressful events; however, in situations where a stressor persists and corticosterone levels remain elevated, the adrenocortical response can be detrimental. A potential ecological stressor for wild birds is parasitism by ectoparasites. We studied the stress response of 11-23-day-old brown pelican (Pelecanus occidentalis) nestlings by measuring plasma corticosterone levels in relation to the presence of the soft tick Carios capensis at two colonies in South Carolina in 2005. We expected to see higher baseline and stress-induced levels of corticosterone for parasitized chicks compared to those nestlings with no ticks. Although nestlings mounted a response to capture stress, tick category was not associated with corticosterone levels at either colony. Our results appear to contrast those of previous studies and indicate that the adrenocortical response of the host is likely dependent on the type of ectoparasite and the degree of infestation. ?? 2009 Elsevier Inc.

  10. Renal Function and Cardiovascular Response to Mental Stress

    Science.gov (United States)

    Seliger, Stephen L.; Katzel, Leslie I.; Fink, Jeffrey C.; Weir, Matthew R.; Waldstein, Shari R.

    2008-01-01

    Background/Aims Cardiovascular reactivity (CVR), defined as an exaggerated hemodynamic response to mental stress, is a putative vascular risk factor and may reflect sympathetic hyperactivity. Chronic kidney disease (CKD) is also associated with sympathetic hyperactivity and vascular risk, but its relationship with CVR is unknown. Methods CVR was assessed in 107 individuals without overt cardiovascular disease or diabetes. Blood pressure and heart rate responses were elicited by three experimental tasks designed to evoke mental stress. Glomerular filtration rate (eGFR) was estimated using the MDRD formula. General linear models estimated the association between renal function and CVR, adjusting for potential confounders. Results Mean age was 66 years and 11% had eGFR of <60 ml/min/1.73 m2. After multivariate adjustment, a low eGFR was associated with a greater stress response of systolic blood pressure, heart rate, and pulse pressure. Associations were only partially attenuated after adjustment for lipids and glucose tolerance. When considered as a continuous variable, lower eGFR was associated with a greater blood pressure response after adjustment for glycemia. Conclusion Although there were relatively few participants with CKD, these results suggest a relationship between CKD and greater CVR. Further investigation is warranted into factors that mediate this relationship and potential clinical consequences of this exaggerated response to stress in CKD. PMID:18025779

  11. Response of Saccharomyces cerevisiae to cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia], e-mail: luamatu@uol.com.br; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Ativacao Neutronica], e-mail: menezes@cdtn.br; Rosa, Carlos Augusto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: carlrosa@icb.ufmg

    2009-07-01

    The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K{sup +} and Na{sup +}) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

  12. Early life stress dampens stress responsiveness in adolescence: Evaluation of neuroendocrine reactivity and coping behavior.

    Science.gov (United States)

    Hsiao, Young-Ming; Tsai, Tsung-Chih; Lin, Yu-Ting; Chen, Chien-Chung; Huang, Chiung-Chun; Hsu, Kuei-Sen

    2016-05-01

    Stressful experiences during early life (ELS) can affect brain development, thereby exerting a profound and long-lasting influence on mental development and psychological health. The stress inoculation hypothesis presupposes that individuals who have early experienced an attenuated form of stressors may gain immunity to its more virulent forms later in life. Increasing evidence demonstrates that ELS may promote the development of subsequent stress resistance, but the mechanisms underlying such adaptive changes are not fully understood. The present study evaluated the impact of fragmented dam-pup interactions by limiting the bedding and nesting material in the cage during postnatal days 2-9, a naturalistic animal model of chronic ELS, on the physiological and behavioral responses to different stressors in adolescent mice and characterized the possible underlying mechanisms. We found that ELS mice showed less social interaction deficits after chronic social defeat stress and acute restraint-tailshock stress-induced impaired long-term potentiation (LTP) and enhanced long-term depression (LTD) in hippocampal CA1 region compared with control mice. The effects of ELS on LTP and LTD were rescued by adrenalectomy. While ELS did not cause alterations in basal emotional behaviors, it significantly enhanced stress coping behaviors in both the tail suspension and the forced swimming tests. ELS mice exhibited a significant decrease in corticosterone response and trafficking of glucocorticoid receptors to the nucleus in response to acute restraint stress. Altogether, our data support the hypothesis that stress inoculation training, via early exposure to manageable stress, may enhance resistance to other unrelated extreme stressors in adolescence. PMID:26881834

  13. ATF4 is involved in the regulation of simulated microgravity induced integrated stress response

    Science.gov (United States)

    Li, Yingxian; Li, Qi; Wang, Xiaogang; Sun, Qiao; Wan, Yumin; Li, Yinghui; Bai, Yanqiang

    Objective: Many important metabolic and signaling pathways have been identified as being affected by microgravity, thereby altering cellular functions such as proliferation, differentiation, maturation and cell survival. It has been demonstrated that microgravity could induce all kinds of stress response such as endoplasmic reticulum stress and oxidative stress et al. ATF4 belongs to the ATF/CREB family of basic region leucine zipper transcription factors. ATF4 is induced by stress signals including anoxia/hypoxia, ER stress, amino acid deprivation and oxidative stress. ATF4 regulates the expression of genes involved in oxidative stress, amino acid synthesis, differentiation, metastasis and angiogenesis. The aim of this study was to examine the changes of ATF4 under microgravity, and to investigate the role of ATF4 in microgravity induced stress. MethodsMEF cells were cultured in clinostat to simulate microgravity. Reverse transcription polymerase chain reaction (RT-PCR) and western blotting were used to examine mRNA and protein levels of ATF4 expression under simulated microgravity in MEF cells. ROS levels were measured with the use of the fluorescent signal H2DCF-DA. GFP-XBP1 stably transfected cell lines was used to detect the extent of ER stress under microgravity by the intensity of GFP. Dual luciferase reporter assay was used to detect the activity of ATF4. Co-immunoprecipitation was performed to analyze protein interaction. Results: ATF4 protein levels in MEF cells increased under simulated microgravity. However, ATF4 mRNA levels were consistent. XBP1 splicing can be induced due to ER stress caused by simulated microgravity. At the same time, ROS levels were also increased. Increased ATF4 could promote the expression of CHOP, which is responsible for cell apoptosis. ATF4 also play an important role in cellular anti-oxidant stress. In ATF4 -/-MEF cells, the ROS levels after H2O2 treatment were obviously higher than that of wild type cells. HDAC4 was

  14. Reactive oxygen species in response of plants to gravity stress

    Science.gov (United States)

    Jadko, Sergiy

    2016-07-01

    Reactive oxygen species (ROS) as second messengers can induce stress response of plants. Thioredoxins (Trx) and peroxiredoxins (Prx) can function as sensors and transmitters of the ROS in stress signaling and antioxidant response. 12-14 days old tissue culture of Arabidopsis thaliana have been investigated. Hypergravity stress was induced by centrifugation at 10 and 20 g during 30 and 90 min and than intensity of spontaneous chemiluminescence (SChL/ROS content), Trx and Prx activities were determined. All experiments were repeated from 3 to 5 times and the obtained data were statistically treated. In the tissue culture under development of the stress there were an increase in intensity of SChL and Trx and Prx activities. Thus, under hypergravity stress in the plant occurred early increase in the ROS level and the ROS induced the increase in the Trx and Prx activities. Prx and Trx can also participate in the formation of stress respons as acceptors and transducers of the redox signals. Increase in the activity of these enzymes primarily aimed at increasing of the total antioxidant activity in the cells to prevent of the plant to development of oxidative degradation by ROS.

  15. Adult hippocampal neurogenesis buffers stress responses and depressive behaviour.

    Science.gov (United States)

    Snyder, Jason S; Soumier, Amélie; Brewer, Michelle; Pickel, James; Cameron, Heather A

    2011-08-03

    Glucocorticoids are released in response to stressful experiences and serve many beneficial homeostatic functions. However, dysregulation of glucocorticoids is associated with cognitive impairments and depressive illness. In the hippocampus, a brain region densely populated with receptors for stress hormones, stress and glucocorticoids strongly inhibit adult neurogenesis. Decreased neurogenesis has been implicated in the pathogenesis of anxiety and depression, but direct evidence for this role is lacking. Here we show that adult-born hippocampal neurons are required for normal expression of the endocrine and behavioural components of the stress response. Using either transgenic or radiation methods to inhibit adult neurogenesis specifically, we find that glucocorticoid levels are slower to recover after moderate stress and are less suppressed by dexamethasone in neurogenesis-deficient mice than intact mice, consistent with a role for the hippocampus in regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Relative to controls, neurogenesis-deficient mice also showed increased food avoidance in a novel environment after acute stress, increased behavioural despair in the forced swim test, and decreased sucrose preference, a measure of anhedonia. These findings identify a small subset of neurons within the dentate gyrus that are critical for hippocampal negative control of the HPA axis and support a direct role for adult neurogenesis in depressive illness.

  16. Fusaric acid induces mitochondrial stress in human hepatocellular carcinoma (HepG2) cells.

    Science.gov (United States)

    Sheik Abdul, Naeem; Nagiah, Savania; Chuturgoon, Anil A

    2016-09-01

    Fusarium spp are common contaminants of maize and produce many mycotoxins, including the fusariotoxin fusaric acid (FA). FA is a niacin related compound, chelator of divalent cations, and mediates toxicity via oxidative stress and possible mitochondrial dysregulation. Sirtuin 3 (SIRT3) is a stress response deacetylase that maintains proper mitochondrial function. We investigated the effect of FA on SIRT3 and oxidative and mitochondrial stress pathways in the hepatocellular carcinoma (HepG2) cell line. We determined FA toxicity (24 h incubation; IC50 = 104 μg/ml) on mitochondrial output, cellular and mitochondrial stress responses, mitochondrial biogenesis and markers of cell death using spectrophotometry, luminometry, qPCR and western blots. FA caused a dose dependent decrease in metabolic activity along with significant depletion of intracellular ATP. FA induced a significant increase in lipid peroxidation, despite up-regulation of the antioxidant transcription factor, Nrf2. FA significantly decreased expression of SIRT3 mRNA with a concomitant decrease in protein expression. Lon protease was also significantly down-regulated. FA induced aberrant mitochondrial biogenesis as evidenced by significantly decreased protein expressions of: PGC-1α, p-CREB, NRF1 and HSP70. Finally, FA activated apoptosis as noted by the significantly increased activity of caspases 3/7 and also induced cellular necrosis. This study provides insight into the molecular mechanisms of FA (a neglected mycotoxin) induced hepatotoxicity. PMID:27390038

  17. Understanding Abiotic Stress Tolerance Mechanisms: Recent Studies on Stress Response in Rice

    Institute of Scientific and Technical Information of China (English)

    Ji-Ping Gao; Dai-Yin Chao; Hong-Xuan Lin

    2007-01-01

    Abiotic stress is the main factor negatively affecting crop growth and productivity worldwide. The advances in physiology, genetics, and molecular biology have greatly improved our understanding of plant responses to stresses. Rice plants are sensitive to various abiotic stresses. In this short review, we present recent progresses in adaptation of rice to salinity, water deficit and submergence. Many studies show that salt tolerance is tightly associated with the ability to maintain ion homeostasis under salinity. Na+ transporter SKC1 unloads NaMrom xylem, plasma membrane NaVHTantiporter SOS1 excludes sodium out of cytosol and tonoplast Na+/H+antiporter NHX1 sequesters Na+ into the vacuole. Silicon deposition in exodermis and endodermis of rice root reduces sodium transport through the apoplastic pathway. A number of transcription factors regulate stress-inducible gene expression that leads to initiating stress responses and establishing plant stress tolerance. Overexpression of some transcription factors, including DREB/CBF and MAC, enhances salt, drought, and cold tolerance in rice. A variant of one of ERF family genes, Sub1A-1, confers immersion tolerance to lowland rice. These findings and their exploitation will hold promise for engineering breeding to protect crop plants from certain abiotic stresses.

  18. Osmotic stress, endogenous abscisic acid and the control of leaf morphology in Hippuris vulgaris L

    Science.gov (United States)

    Goliber, T. E.; Feldman, L. J.

    1989-01-01

    Previous reports indicate that heterophyllous aquatic plants can be induced to form aerial-type leaves on submerged shoots when they are grown in exogenous abscisic acid (ABA). This study reports on the relationship between osmotic stress (e.g. the situation encountered by a shoot tip when it grows above the water surface), endogenous ABA (as measured by gas chromatography-electron capture detector) and leaf morphology in the heterophyllous aquatic plant, Hippuris vulgaris. Free ABA could not be detected in submerged shoots of H. vulgaris but in aerial shoots ABA occurred at ca. 40 ng (g fr wt)-1. When submerged shoots were osmotically stressed ABA appeared at levels of 26 to 40 ng (g fr wt)-1. These and other data support two main conclusions: (1) Osmotically stressing a submerged shoot causes the appearance of detectable levels of ABA. (2) The rise of ABA in osmotically stressed submerged shoots in turn induces a change in leaf morphology from the submerged to the aerial form. This corroborates the hypothesis that, in the natural environment, ABA levels rise in response to the osmotic stress encountered when a submerged shoot grows up through the water/air interface and that the increased ABA leads to the production of aerial-type leaves.

  19. Microinjection of valproic acid into the ventrolateral orbital cortex enhances stress-related memory formation.

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    Full Text Available There is collecting evidence suggesting that the process of chromatin remodeling such as changes in histone acetylation contribute to the formation of stress-related memory. Recently, the ventrolateral orbital cortex (VLO, a major subdivision of orbitofrontal cortex (OFC, was shown to be involved in antidepressant-like actions through epigenetic mechanisms. Here, we further investigated the effects of the histone deacetylase inhibitor (HDACi valproic acid (VPA on stress-related memory formation and the underlying molecular mechanisms by using the traditional two-day forced swimming test (FST. The results showed that VPA significantly increased the immobility time on day 2 when infused into the VLO before the initial forced swim stress on day 1. The learned immobility response to the stress was associated with increased phosphorylation of extracellular signal-regulated kinase (ERK in VLO and hippocampus on the first day. The levels of phosphorylated ERK (phospho-ERK in VLO and hippocampus were significantly decreased when retested 24 h later. The pretreatment with intra-VLO VPA infusion further reduced the activation of ERK on day 2 and day 7 compared with the saline controls. Moreover, the VPA infusion pretreatment also induced a significantly decreased BDNF level in the VLO on day 2, whereas no change was detected in the hippocampus. These findings suggest that VPA enhance the memories of emotionally stressful events and the ERK activity is implicated in stimulating adaptive and mnemonic processes in case the event would recur.

  20. Neural regulation of the stress response: glucocorticoid feedback mechanisms

    Directory of Open Access Journals (Sweden)

    J.P. Herman

    2012-04-01

    Full Text Available The mammalian stress response is an integrated physiological and psychological reaction to real or perceived adversity. Glucocorticoids are an important component of this response, acting to redistribute energy resources to both optimize survival in the face of challenge and to restore homeostasis after the immediate challenge has subsided. Release of glucocorticoids is mediated by the hypothalamo-pituitary-adrenal (HPA axis, driven by a neural signal originating in the paraventricular nucleus (PVN. Stress levels of glucocorticoids bind to glucocorticoid receptors in multiple body compartments, including the brain, and consequently have wide-reaching actions. For this reason, glucocorticoids serve a vital function in negative feedback inhibition of their own secretion. Negative feedback inhibition is mediated by a diverse collection of mechanisms, including fast, non-genomic feedback at the level of the PVN, stress-shut-off at the level of the limbic system, and attenuation of ascending excitatory input through destabilization of mRNAs encoding neuropeptide drivers of the HPA axis. In addition, there is evidence that glucocorticoids participate in stress activation via feed-forward mechanisms at the level of the amygdala. Feedback deficits are associated with numerous disease states, underscoring the necessity for adequate control of glucocorticoid homeostasis. Thus, rather than having a single, defined feedback ‘switch’, control of the stress response requires a wide-reaching feedback ‘network’ that coordinates HPA activity to suit the overall needs of multiple body systems.

  1. Proteomic Analysis of Tomato Seedlings Response to Salt Stress

    Institute of Scientific and Technical Information of China (English)

    Xue Zhao; Feng Han; Shihua Shen

    2012-01-01

    The two species (Solanum pimpinellifolium-PI and S.lycopersicum-MM) of tomato showed marked differences in their responses to NaCI stress.PI appeared to be more tolerant to salt than MM.Comparative two-dimensional electrophoresis revealed that 187 and 110 protein spots were differentially expressed in the roots of PI and MM,respectively,in response to salt stress.Out of these spots,a total of 96 and 61 proteins were identified by MALDI-TOF MS analysis.The proteins identified included many previously characterized stress-responsive proteins and others related to processes including scavenging for reactive species; metabolism of energy,signal transduction; protein synthesis,cell growth and differentiation et al.The role of some of the proteins involved in the antioxidant defense mechanism,ion transport and compartmentalization of ions,and cell signaling pathways were discussed.Collectively,this work suggest that PI has more efficient antioxidant and defense machinery than MM,and that this is important for adapting to salt stress and for withstanding the oxidative stress imposed by high salt levels.

  2. Silver nanoparticles induce endoplasmatic reticulum stress response in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Verena [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Capelle, Martinus [Crucell, P.O. Box 2048, NL-2301 Leiden (Netherlands); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich, Department of Environmental Systems Science, CH-8092 Zürich (Switzerland)

    2013-10-15

    Silver nanoparticles (AgNPs) find increasing applications, and therefore humans and the environment are increasingly exposed to them. However, potential toxicological implications are not sufficiently known. Here we investigate effects of AgNPs (average size 120 nm) on zebrafish in vitro and in vivo, and compare them to human hepatoma cells (Huh7). AgNPs are incorporated in zebrafish liver cells (ZFL) and Huh7, and in zebrafish embryos. In ZFL cells AgNPs lead to induction of reactive oxygen species (ROS), endoplasmatic reticulum (ER) stress response, and TNF-α. Transcriptional alterations also occur in pro-apoptotic genes p53 and Bax. The transcriptional profile differed in ZFL and Huh7 cells. In ZFL cells, the ER stress marker BiP is induced, concomitant with the ER stress marker ATF-6 and spliced XBP-1 after 6 h and 24 h exposure to 0.5 g/L and 0.05 g/L AgNPs, respectively. This indicates the induction of different pathways of the ER stress response. Moreover, AgNPs induce TNF-α. In zebrafish embryos exposed to 0.01, 0.1, 1 and 5 mg/L AgNPs hatching was affected and morphological defects occurred at high concentrations. ER stress related gene transcripts BiP and Synv are significantly up-regulated after 24 h at 0.1 and 5 mg/L AgNPs. Furthermore, transcriptional alterations occurred in the pro-apoptotic genes Noxa and p21. The ER stress response was strong in ZFL cells and occurred in zebrafish embryos as well. Our data demonstrate for the first time that AgNPs lead to induction of ER stress in zebrafish. The induction of ER stress can have several consequences including the activation of apoptotic and inflammatory pathways. - Highlights: • Effects of silver nanoparticles (120 nm AgNPs) are investigated in zebrafish. • AgNPs induce all ER stress reponses in vitro in zebrafish liver cells. • AgNPs induce weak ER stress in zebrafish embryos. • AgNPs induce oxidative stress and transcripts of pro-apoptosis genes.

  3. Erythropoietin Action in Stress Response, Tissue Maintenance and Metabolism

    Directory of Open Access Journals (Sweden)

    Yuanyuan Zhang

    2014-06-01

    Full Text Available Erythropoietin (EPO regulation of red blood cell production and its induction at reduced oxygen tension provides for the important erythropoietic response to ischemic stress. The cloning and production of recombinant human EPO has led to its clinical use in patients with anemia for two and half decades and has facilitated studies of EPO action. Reports of animal and cell models of ischemic stress in vitro and injury suggest potential EPO benefit beyond red blood cell production including vascular endothelial response to increase nitric oxide production, which facilitates oxygen delivery to brain, heart and other non-hematopoietic tissues. This review discusses these and other reports of EPO action beyond red blood cell production, including EPO response affecting metabolism and obesity in animal models. Observations of EPO activity in cell and animal model systems, including mice with tissue specific deletion of EPO receptor (EpoR, suggest the potential for EPO response in metabolism and disease.

  4. Simple Experiments To Demonstrate Proton Flux in Pseudomonas after Alkaline or Acidic Stress

    Science.gov (United States)

    Previtali, Gabriela; Giordano, Walter; Domenech, Carlos E.

    2003-12-01

    This laboratory introduces chemistry students to the ability of microorganisms to adapt to acidic or alkaline environmental conditions. A laboratory experiment to ascertain the bacterial response to the stress produced by suspension in different pH solutions has been developed. The experiment may be performed in several versions depending on the availability of lab equipment and the chemistry level of the students. This laboratory experiment has the pedagogical advantage of giving chemistry students experience with the application of various pH levels to a biological system and enables the students to expand their understanding of pH to mean more than a strictly chemical concept.

  5. Response and energy dissipation of rock under stochastic stress waves

    Institute of Scientific and Technical Information of China (English)

    DENG Jian; BIAN Li

    2007-01-01

    The response and energy dissipation of rock under stochastic stress waves were analyzed based on dynamic fracture criterion of brittle materials integrating with Fourier transform methods of spectral analysis When the stochastic stress waves transnut through rocks,the frequency and energy ratio of harmonic components were calculated by analytical and discrete analysis methods.The stress waves in shale, malmstone and liparite were taken as examples to illustrate the proposed analysis methods.The results show the harder the rock, the less absorption of energy,the more the useless elastic waves transmitting through rock, and the narrower the cutoff frequency to fracture rock.When the whole stress energy doubles either by doubling the duration time or byincreasing the amplitude of stress wave, ratio of the energy of elastic waves transmitting through rock to me whole stress energy (i.e.energy dissipation ratio)is decreased to 10%-15%. When doubling the duration time.the cutoff frequency to fracture rock remains constant.However, with the increase of the amplitude of stress wave. the cutoff frequency increases accordingly.

  6. REM SLEEP REBOUND AS AN ADAPTIVE RESPONSE TO STRESSFUL SITUATIONS

    Directory of Open Access Journals (Sweden)

    Deborah eSuchecki

    2012-04-01

    Full Text Available Stress and sleep are related to each other in a bidirectional way. If on one hand poor or inadequate sleep exacerbates emotional, behavioral and stress-related responses, on the other hand acute stress induces sleep rebound, most likely as a form to cope with the adverse stimuli. Chronic stress, conversely, has been claimed to be one of the triggering factors of emotional-related sleep disorders, such as insomnia, depressive- and anxiety-disorders. These outcomes are dependent on individual psychobiological characteristics, which confer more complexity to the stress-sleep relationship. Its neurobiology has only recently begun to be explored, through animal models, which are also valuable for the development of potential therapeutic agents and preventive actions. This review seeks to present data on the effects of stress on sleep and the different approaches used to study this relationship as well as possible neurobiological underpinnings and mechanisms involved. The results of numerous studies in humans and animals indicate that increased sleep, especially the REM phase, following a stressful situation is an important adaptive behavior for recovery. However, this endogenous advantage appears to be impaired in human beings and rodent strains that exhibit high levels of anxiety and anxiety-like behavior.

  7. Role of Glyoxylate Shunt in Oxidative Stress Response.

    Science.gov (United States)

    Ahn, Sungeun; Jung, Jaejoon; Jang, In-Ae; Madsen, Eugene L; Park, Woojun

    2016-05-27

    The glyoxylate shunt (GS) is a two-step metabolic pathway (isocitrate lyase, aceA; and malate synthase, glcB) that serves as an alternative to the tricarboxylic acid cycle. The GS bypasses the carbon dioxide-producing steps of the tricarboxylic acid cycle and is essential for acetate and fatty acid metabolism in bacteria. GS can be up-regulated under conditions of oxidative stress, antibiotic stress, and host infection, which implies that it plays important but poorly explored roles in stress defense and pathogenesis. In many bacterial species, including Pseudomonas aeruginosa, aceA and glcB are not in an operon, unlike in Escherichia coli In P. aeruginosa, we explored relationships between GS genes and growth, transcription profiles, and biofilm formation. Contrary to our expectations, deletion of aceA in P. aeruginosa improved cell growth under conditions of oxidative and antibiotic stress. Transcriptome data suggested that aceA mutants underwent a metabolic shift toward aerobic denitrification; this was supported by additional evidence, including up-regulation of denitrification-related genes, decreased oxygen consumption without lowering ATP yield, increased production of denitrification intermediates (NO and N2O), and increased cyanide resistance. The aceA mutants also produced a thicker exopolysaccharide layer; that is, a phenotype consistent with aerobic denitrification. A bioinformatic survey across known bacterial genomes showed that only microorganisms capable of aerobic metabolism possess the glyoxylate shunt. This trend is consistent with the hypothesis that the GS plays a previously unrecognized role in allowing bacteria to tolerate oxidative stress. PMID:27036942

  8. ADRENERGIC RESPONSES TO STRESS: TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL CHANGES

    OpenAIRE

    Wong, Dona L.; Tai, T. C.; Wong-Faull, David C.; Claycomb, Robert; Kvetnansky, Richard

    2008-01-01

    Stress effects on adrenergic responses in rats were examined in adrenal medulla, the primary source of circulating epinephrine (Epi). Irrespective of duration, immobilization (IMMO) increased adrenal corticosterone to the same extent. In contrast, epinephrine changed little, suggesting that Epi synthesis replenishes adrenal pools and sustains circulating levels for the heightened alertness and physiological changes required of the "flight or fight" response. IMMO also induced the epinephrine-...

  9. Husbandry of zebrafish, Danio rerio, and the cortisol stress response.

    Science.gov (United States)

    Pavlidis, Michail; Digka, Nikoletta; Theodoridi, Antonia; Campo, Aurora; Barsakis, Konstantinos; Skouradakis, Gregoris; Samaras, Athanasios; Tsalafouta, Alexandra

    2013-12-01

    The effect of common husbandry conditions (crowding, social environment, water quality, handling, and background color) on the cortisol stress response in adult zebrafish, Danio rerio, was investigated to check the usefulness of zebrafish as a model organism in aquaculture research. In addition, a noninvasive methodology for assessing stress was evaluated. Zebrafish showed a fast cortisol response with high values at 30 min that returned to basal levels within 2 h of poststress. There was a significant positive correlation between trunk cortisol concentrations and the free water cortisol rate (r(2)=0.829-0.850, pzebrafish. It is concluded that adult laboratory zebrafish had a preference for a transparent or black background aquarium, at a number of 10 individuals per 2 L of available water volume, to express their normal behavior and avoid increased cortisol stress reaction.

  10. Enterovirus Control of Translation and RNA Granule Stress Responses

    Directory of Open Access Journals (Sweden)

    Richard E. Lloyd

    2016-03-01

    Full Text Available Enteroviruses such as poliovirus (PV and coxsackievirus B3 (CVB3 have evolved several parallel strategies to regulate cellular gene expression and stress responses to ensure efficient expression of the viral genome. Enteroviruses utilize their encoded proteinases to take over the cellular translation apparatus and direct ribosomes to viral mRNAs. In addition, viral proteinases are used to control and repress the two main types of cytoplasmic RNA granules, stress granules (SGs and processing bodies (P-bodies, PBs, which are stress-responsive dynamic structures involved in repression of gene expression. This review discusses these processes and the current understanding of the underlying mechanisms with respect to enterovirus infections. In addition, the review discusses accumulating data suggesting linkage exists between RNA granule formation and innate immune sensing and activation.

  11. Enterovirus Control of Translation and RNA Granule Stress Responses

    Science.gov (United States)

    Lloyd, Richard E.

    2016-01-01

    Enteroviruses such as poliovirus (PV) and coxsackievirus B3 (CVB3) have evolved several parallel strategies to regulate cellular gene expression and stress responses to ensure efficient expression of the viral genome. Enteroviruses utilize their encoded proteinases to take over the cellular translation apparatus and direct ribosomes to viral mRNAs. In addition, viral proteinases are used to control and repress the two main types of cytoplasmic RNA granules, stress granules (SGs) and processing bodies (P-bodies, PBs), which are stress-responsive dynamic structures involved in repression of gene expression. This review discusses these processes and the current understanding of the underlying mechanisms with respect to enterovirus infections. In addition, the review discusses accumulating data suggesting linkage exists between RNA granule formation and innate immune sensing and activation. PMID:27043612

  12. Genome-wide identification, expression analysis of auxin-responsive GH3 family genes in maize (Zea mays L.) under abiotic stresses

    Institute of Scientific and Technical Information of China (English)

    Shangguo Feng; Runqing Yue; Sun Tao Yanjun Yang; Lei Zhang; Mingfeng Xu; Huizhong Wang; Chenjia Shen

    2015-01-01

    Auxin is involved in different aspects of plant growth and development by regulating the expression of auxin-responsive family genes. As one of the three major auxin-responsive families, GH3 (Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid (IAA) to amino acids. However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown. Here, the latest updated maize (Zea mays L.) reference genome sequence was used to characterize and analyze the ZmGH3 family genes from maize. The results showed that 13 ZmGH3 genes were mapped on five maize chromosomes (total 10 chromosomes). Highly diversified gene structures and tissue-specific expression patterns suggested the possibility of function diversification for these genes in response to environmental stresses and hormone stimuli. The expression patterns of ZmGH3 genes are responsive to several abiotic stresses (salt, drought and cadmium) and major stress-related hormones (abscisic acid, salicylic acid and jasmonic acid). Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The respon-siveness of ZmGH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that ZmGH3s are involved in maize tolerance to environmental stresses.

  13. Stress and fear responses in the teleost pallium

    DEFF Research Database (Denmark)

    Silva, Patricia Isabel da Mota E.; Martins, C.I.M.; Khan, Uniza Wahid;

    2015-01-01

    largely unknown. In the present study the involvement of Dl and Dm in such responses was investigated by exposing Nile tilapia (Oreochromis niloticus) to a standardized confinement stress and to skin extract from conspecifics. Nile tilapia develops a characteristic anticipatory behaviour to hand feeding...

  14. Behaviour and stress responses in horses with gastric ulceration

    DEFF Research Database (Denmark)

    Malmkvist, Jens; Poulsen, Janne Møller; Luthersson, Nanna;

    2012-01-01

    Only little is known about behaviour and stress responses in horses with gastric ulceration, despite the high prevalence of this condition. Our objectives in the present study was to (i) describe the severity of gastric ulceration in horses, housed under relatively standardised conditions, and (ii...... may be e.g. trained differently dependent on breeding line. Ulcer horses pawed more (P biting...

  15. Physiological Response to Drought Stress at Different Stages in Peanut

    Science.gov (United States)

    Drought is a major factor in reducing productivity in peanut (Arachis hypogaea L.). The objectives of this study were to: 1) investigate the response patterns of relative water content (RWC), specific leaf area (SLA), and leaf dry mater content (LDMC) to drought stress at three stages of 30 60, and ...

  16. The insect capa neuropeptides impact desiccation and cold stress responses

    Science.gov (United States)

    Background: Insects are so successful because of great resistance to environmental stress, yet little is known about how such responses may be mediated by the neuroendocrine system. Results: We provide evidence that the capability (capa) neuropeptide gene and peptide are critical mediators of desic...

  17. Sympathetic and parasympathetic responses to social stress across adolescence

    NARCIS (Netherlands)

    Hollenstein, T.P.; McNeely, A.; Eastabrook, J.; Mackey, A.; Flynn, J.

    2012-01-01

    Many transformations that occur in adolescence are related to emotion and emotion regulation, yet very little is known about the autonomic underpinnings of these changes. The aim of the study was to document age-related differences in autonomic responses to social stress and relations to emotion reg

  18. CENTRAL AMYGDALOID INVOLVEMENT IN NEUROENDOCRINE CORRELATES OF CONDITIONED STRESS RESPONSES

    NARCIS (Netherlands)

    ROOZENDAAL, B; KOOLHAAS, JM; BOHUS, B

    1992-01-01

    The purpose of this study was to examine the effects of bilateral electrolytic lesions of the central nucleus of the amygdala (CEA) in comparison with sham lesions on neuroendocrine responses during conditioned emotional stress in male Wistar rats. Lesions in the CEA, made either before or after the

  19. Phospholipid signaling responses in salt-stressed rice leaves

    NARCIS (Netherlands)

    E. Darwish; C. Testerink; M. Khalil; O. El-Shihy; T. Munnik

    2009-01-01

    Salinity is one of the major environmental factors limiting growth and productivity of rice plants. In this study, the effect of salt stress on phospholipid signaling responses in rice leaves was investigated. Leaf cuts were radiolabeled with 32 P-orthophosphate and the lipids extracted and analyzed

  20. Adaptive Patterns of Stress Responsivity: A Preliminary Investigation

    Science.gov (United States)

    Del Giudice, Marco; Hinnant, J. Benjamin; Ellis, Bruce J.; El-Sheikh, Mona

    2012-01-01

    The adaptive calibration model (ACM) is an evolutionary-developmental theory of individual differences in stress responsivity. In this article, we tested some key predictions of the ACM in a middle childhood sample (N = 256). Measures of autonomic nervous system activity across the sympathetic and parasympathetic branches validated the 4-pattern…

  1. Stress response signaling and virulence: insights from entomopathogenic fungi.

    Science.gov (United States)

    Ortiz-Urquiza, Almudena; Keyhani, Nemat O

    2015-08-01

    The Ascomycete fungal insect pathogens, Beauveria and Metarhizium spp. have emerged as model systems with which to probe diverse aspects of fungal growth, stress response, and pathogenesis. Due to the availability of genomic resources and the development of robust methods for genetic manipulation, the last 5 years have witnessed a rapid increase in the molecular characterization of genes and their pathways involved in stress response and signal transduction in these fungi. These studies have been performed mainly via characterization of gene deletion/knockout mutants and have included the targeting of general proteins involved in stress response and/or virulence, e.g. catalases, superoxide dismutases, and osmolyte balance maintenance enzymes, membrane proteins and signaling pathways including GPI anchored proteins and G-protein coupled membrane receptors, MAPK pathways, e.g. (i) the pheromone/nutrient sensing, Fus3/Kss1, (ii) the cell wall integrity, Mpk1, and (iii) the high osmolarity, Hog1, the PKA/adenyl cyclase pathway, and various downstream transcription factors, e.g. Msn2, CreA and Pac1. Here, we will discuss current research that strongly suggests extensive underlying contributions of these biochemical and signaling pathways to both abiotic stress response and virulence. PMID:25113413

  2. Fatty-acid metabolism is involved in stress-resistance mechanisms of Caenorhabditis elegans

    OpenAIRE

    Horikawa, Makoto; Sakamoto, Kazuichi

    2009-01-01

    Fatty acids are the major components of the phospholipid bilayer and are involved in several functions of cell membrane. We previously reported that fatty-acid metabolism is involved in the regulation of DAF-2/insulin signal in Caenorhabditis elegans. In this study, we investigate the role of fatty-acid metabolism in stress resistance with respect to daf-16 in nematode. We found that fatty-acid metabolism regulates heat, osmotic, and oxidative-stress resistance in C. elegans. RNA interference...

  3. β-aminobutyric acid mediated drought stress alleviation in maize (Zea mays L.).

    Science.gov (United States)

    Shaw, Arun K; Bhardwaj, Pardeep K; Ghosh, Supriya; Roy, Sankhajit; Saha, Suman; Sherpa, Ang R; Saha, Samir K; Hossain, Zahed

    2016-02-01

    The present study highlights the role of β-aminobutyric acid (BABA) in alleviating drought stress effects in maize (Zea mays L.). Chemical priming was imposed by pretreating 1-week-old plants with 600 μM BABA prior to applying drought stress. Specific activities of key antioxidant enzymes and metabolites (ascorbate and glutathione) levels of ascorbate-glutathione cycle were studied to unravel the priming-induced modulation of plant defense system. Furthermore, changes in endogenous ABA and JA concentrations as well as mRNA expressions of key genes involved in their respective biosynthesis pathways were monitored in BABA-primed (BABA+) and non-primed (BABA-) leaves of drought-challenged plants to better understand the mechanistic insights into the BABA-induced hormonal regulation of plant response to water-deficit stress. Accelerated stomatal closure, high relative water content, and less membrane damage were observed in BABA-primed leaves under water-deficit condition. Elevated APX and SOD activity in non-primed leaves found to be insufficient to scavenge all H2O2 and O2 (·-) resulting in oxidative burst as evident after histochemical staining with NBT and DAB. A higher proline accumulation in non-primed leaves also does not give much protection against drought stress. Increased GR activity supported with the enhanced mRNA and protein expressions might help the BABA-primed plants to maintain a high GSH pool essential for sustaining balanced redox status to counter drought-induced oxidative stress damages. Hormonal analysis suggests that in maize, BABA-potentiated drought tolerance is primarily mediated through JA-dependent pathway by the activation of antioxidant defense systems while ABA biosynthesis pathway also plays an important role in fine-tuning of drought stress response.

  4. Global metabolomic responses of Nitrosomonas europaea 19718 to cold stress and altered ammonia feeding patterns

    KAUST Repository

    Lu, Huijie

    2015-11-05

    © 2015 Springer-Verlag Berlin Heidelberg The model ammonia-oxidizing bacterium Nitrosomonas europaea represents one of the environmentally and biotechnologically significant microorganisms. Genome-based studies over the last decade have led to many intriguing discoveries about its cellular biochemistry and physiology. However, knowledge regarding the regulation of overall metabolic routes in response to various environmental stresses is limited due to a lack of comprehensive, time-resolved metabolomic analyses. In this study, gas chromatography–mass spectrometry (GC-MS)-based metabolic profiling was performed to characterize the temporal variations of N. europaea 19718 intercellular metabolites in response to varied temperature (23 and 10 °C) and ammonia feeding patterns (shock loading and continuous feeding of 20 mg N/L). Approximately 87 metabolites were successfully identified and mapped to the existing pathways of N. europaea 19718, allowing interpretation of the influence of temperature and feeding pattern on metabolite levels. In general, varied temperature had a more profound influence on the overall metabolism than varied feeding patterns. Total extracellular metabolite concentrations (relative to internal standards and normalized to biomass weight) were lower under cold stress and shock loading conditions compared with the control (continuous feeding at 23 °C). Cold stress caused the widespread downregulation of metabolites involved in central carbon metabolism, amino acid, and lipid synthesis (e.g., malonic acid, succinic acid, putrescine, and phosphonolpyruvate). Metabolites that showed differences under varied feeding patterns were mainly involved in nucleotide acid, amino acid, and lipid metabolism (e.g., adenine, uracil, and spermidine). This study highlighted the roles of central carbon and nitrogen metabolism in countering cold stress and altered ammonia availability. In addition, transcriptomic, proteomic, and metabolomic data from three

  5. Biochemical and molecular changes in response to aluminium-stress in highbush blueberry (Vaccinium corymbosum L.).

    Science.gov (United States)

    Inostroza-Blancheteau, Claudio; Reyes-Díaz, Marjorie; Aquea, Felipe; Nunes-Nesi, Adriano; Alberdi, Miren; Arce-Johnson, Patricio

    2011-09-01

    Aluminium (Al) stress is an important factor limiting crop yields in acid soils. Despite this, very little is known about the mechanisms of resistance to this stress in woody plants. To understand the mechanisms of Al-toxicity and response in blueberries, we compared the impact of Al-stress in Al-resistant and Al-sensitive genotypes using Vaccinium corymbosum L. (Ericaceae) as a plant model. We investigated the effect of Al-stress on the physiological performance, oxidative metabolism and expression of genes that encode antioxidant enzymes in two V. corymbosum cultivars maintained hydroponically with AlCl(3) (0 and 100 μM). Microscopic analyses of Al-treated root tips suggested a higher degree of Al-induced morphological injury in Bluegold (sensitive genotype) compared to Brigitta (resistant genotype). Furthermore, the results indicated that Brigitta had a greater ability to control oxidative stress under Al-toxicity, as reflected by enhancement of several antioxidative and physiological properties (radical scavenging activity: RSA, superoxide dismutase: SOD and catalase: CAT; maximum quantum yield: Fv/Fm, effective quantum yield: ФPSII, electron transport rate: ETR and non-photochemical quenching: NPQ). Finally, we analyzed the expression of genes homologous to GST and ALDH, which were identified in a global expression analysis. In the resistant genotype, the expression of these genes in response to Al-stress was greater in leaves than in roots.

  6. Mass spectrometry-based plant metabolomics: Metabolite responses to abiotic stress.

    Science.gov (United States)

    Jorge, Tiago F; Rodrigues, João A; Caldana, Camila; Schmidt, Romy; van Dongen, Joost T; Thomas-Oates, Jane; António, Carla

    2016-09-01

    Metabolomics is one omics approach that can be used to acquire comprehensive information on the composition of a metabolite pool to provide a functional screen of the cellular state. Studies of the plant metabolome include analysis of a wide range of chemical species with diverse physical properties, from ionic inorganic compounds to biochemically derived hydrophilic carbohydrates, organic and amino acids, and a range of hydrophobic lipid-related compounds. This complexitiy brings huge challenges to the analytical technologies employed in current plant metabolomics programs, and powerful analytical tools are required for the separation and characterization of this extremely high compound diversity present in biological sample matrices. The use of mass spectrometry (MS)-based analytical platforms to profile stress-responsive metabolites that allow some plants to adapt to adverse environmental conditions is fundamental in current plant biotechnology research programs for the understanding and development of stress-tolerant plants. In this review, we describe recent applications of metabolomics and emphasize its increasing application to study plant responses to environmental (stress-) factors, including drought, salt, low oxygen caused by waterlogging or flooding of the soil, temperature, light and oxidative stress (or a combination of them). Advances in understanding the global changes occurring in plant metabolism under specific abiotic stress conditions are fundamental to enhance plant fitness and increase stress tolerance. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 35:620-649, 2016. PMID:25589422

  7. Isolation and expression studies of the ERD15 gene involved in drought-stressed responses.

    Science.gov (United States)

    Shao, H H; Chen, S D; Zhang, K; Cao, Q H; Zhou, H; Ma, Q Q; He, B; Yuan, X H; Wang, Y; Chen, Y H; Yong, B

    2014-01-01

    The early response to the dehydration 15 (ERD15) gene is widely involved in the processes of signal transduction, programmed cell death, gene transcription, and stress tolerance in plants. In a previous study, the ERD15 gene was shown to be an important regulator of the abscisic acid response and salicylic acid-dependent defense pathway, acting as an important negative regulator of abscisic acid. The complete IbERD15 gene (accession No. KF723428) was isolated by reverse transcription-polymerase chain reaction. The IbERD15 gene contains an open reading frame of 504 bp, encodes a peptide of 167 amino acids, and has a molecular mass of 18.725 kDa. The transcript levels of the IbERD15 gene in a variety of tissues were examined by digital gene expression profiling. The roots of the sweet potato were treated by 3 degrees of polyethylene glycol, and the results indicate that the IbERD15 gene might play an important role in the defense response to drought stress. Moreover, the IbERD15 gene was successfully transformed into yeast cells for analysis of drought tolerance in transgenic yeast. PMID:25526205

  8. Expression analysis of bZIP transcription factor encoding genes in response to water deficit stress in rice.

    Science.gov (United States)

    Ali, Kishwar; Rai, R D; Tyagi, Aruna

    2016-05-01

    In plants, basic region/leucine zipper motif (bZIP) transcription factors regulate several developmental processes and activate genes in response to biotic and abiotic stresses. Role of stress responsive bZIP transcription factors was studied in paddy in relation to different stages of development and water deficit stress (WDS) in a drought tolerant cultivar N22 and susceptible IR 64. Further, relative water content (RWC), membrane stability index (MSI) and abscisic acid (ABA) content were measured as indices of WDS at different stages of development and levels of stress. Expression of stress responsive bZIP transcription factors was directly correlated to developmental stage and WDS and indirectly to RWC, MSI and ABA content. PMID:27319052

  9. Secondary stress responses of zebrafish to different pH: Evaluation in a seasonal manner

    Directory of Open Access Journals (Sweden)

    Md. Mahiuddin Zahangir

    2015-11-01

    Full Text Available Stress is one of the most critical factors in fish health. The response to stress in fish is characterized by the stimulation of the hypothalamus, which results in the activation of the neuroendocrine system and a subsequent cascade of metabolic and physiological changes. The present paper deals with the stress responses of water pH on certain biochemical indices and hematological parameters of zebrafish in a seasonal basis. Zebrafish were exposed to different pH e.g., 7.2, 5.0 and 10.0 and the secondary stress responses were observed. The result showed that exposure to pH 5.0 and 10.0 on zebrafish exerted stresses with reference to seasons. Higher values of blood glucose content observed in the month of summer than the month of winter and females showed higher values than males. Chronic effects of pH on the hematological parameters were also significant between these seasons. In conclusion, exposure to pH at sub-lethal concentrations induced biochemical and hematological alterations in zebrafish and offers a simple tool to evaluate the potential risk of polluted water (acid and base to fish.

  10. Expression Analysis of MYC Genes from Tamarix hispida in Response to Different Abiotic Stresses

    Directory of Open Access Journals (Sweden)

    Guifeng Liu

    2012-01-01

    Full Text Available The MYC genes are a group of transcription factors containing both bHLH and ZIP motifs that play important roles in the regulation of abscisic acid (ABA-responsive genes. In the present study, to investigate the roles of MYC genes under NaCl, osmotic and ABA stress conditions, nine MYC genes were cloned from Tamarix hispida. Real-time reverse-transcriptase (RT-PCR showed that all nine MYC genes were expressed in root, stem and leaf tissues, but that the levels of the transcripts of these genes in the various tissues differed notably. The MYC genes were highly induced in the roots in response to ABA, NaCl and osmotic stresses after 3 h; however, in the stem and leaf tissues, MYC genes were highly induced only when exposed to these stresses for 6 h. In addition, most of these MYC genes were highly expressed in roots in comparison with stems and leaves. Furthermore, the MYC genes were more highly induced in roots than in stem and leaf tissues, indicating that these genes may play roles in stress responses mainly in the roots rather than the stems and leaves. The results of this present study suggest that MYCs are involved in salt and osmotic stress tolerances and are controlled by the ABA signal transduction pathway.

  11. Transactional Associations between Youths' Responses to Peer Stress and Depression: The Moderating Roles of Sex and Stress Exposure

    Science.gov (United States)

    Agoston, Anna M.; Rudolph, Karen D.

    2011-01-01

    This study examined transactional associations between responses to peer stress and depression in youth. Specifically, it tested the hypotheses that (a) depression would predict fewer effortful responses and more involuntary, dysregulated responses to peer stress over time; and (b) fewer adaptive and more maladaptive responses would predict…

  12. Mitigating effects of salicylic acid against herbicidal stress

    Directory of Open Access Journals (Sweden)

    Singh N. B.

    2012-11-01

    Full Text Available Background, the context and purpose of the study: Pendimethalin [N-(1-ethyl propyl-2, 6-dinitro-3, 4 xylidine] is one of the most commonly used herbicides. It induces harmful effect on non-target plants besides controlling the weed emergence. Salicylic acid (SA plays an important role in abiotic stress tolerance. Present study was to assess the comparative efficacy of SA in combination with different concentrations of pendimethalin on black gram (Vigna mungo. The seeds of test plant were treated with field relevant concentrations (2, 5 and 10 ppm of pendimethalin (P and in combination with SA (0.5 mM to observe effect of SA against herbicide toxicity. Experiment was performed in petri dish as well as in pot culture. The toxic effect of pendimethalin and SA on seed germination (SG, radicle length (RL and mitotic index (MI was evaluated in petri dish culture. Seedling height, pigments, protein, sugar contents and lipid peroxidation (LP of 15 days old seedling were measured in pot culture. Total antioxidants (TA were monitored as plant defence against oxidative stress. Results, the main findings: Results showed that SG and seedling growth of Vigna mungo decreased under P1, P2 and P3 treatments. RL and MI were also reduced significantly (p<0.05 in treatments with herbicide and reduction was more pronounced in P3 treatment. A slight increase of SG and seedling growth was observed in P2 treatment compared to P1. Herbicide treatment remarkably declined pigment, protein and sugar contents of the seedlings when compared with control. TA and malondialdehyde (MDA content increase significantly under pendimethalin treated seedlings. Combined treatment (P+SA elevated growth of the seedlings. As a consequence of herbicidal stress, SA enhanced SG, RL, MI, pigment, protein and sugar content significantly. Under combined treatments,LP and TA were decreased when compared with pendimethalin treatment. Conclusions, brief summary and potential implications: SA

  13. Associations Between Paternal Responsiveness and Stress Responsiveness in the Biparental California Mouse, Peromyscus californicus

    OpenAIRE

    Chauke, Miyetani

    2012-01-01

    The mechanistic basis of paternal behavior in mammals is poorly understood. Assuming there are parallels between the factors mediating maternal and paternal behavior, it can be expected that the onset of paternal behavior is facilitated by reductions in stress responsiveness, as occurs in females of several mammalian species. This dissertation describes studies investigating the role of stress responsiveness in the expression of paternal behavior in biparental, monogamous California mice (Per...

  14. Regulation Systems of Bacteria such as Escherichia coli in Response to Nutrient Limitation and Environmental Stresses

    Directory of Open Access Journals (Sweden)

    Kazuyuki Shimizu

    2013-12-01

    Full Text Available An overview was made to understand the regulation system of a bacterial cell such as Escherichia coli in response to nutrient limitation such as carbon, nitrogen, phosphate, sulfur, ion sources, and environmental stresses such as oxidative stress, acid shock, heat shock, and solvent stresses. It is quite important to understand how the cell detects environmental signals, integrate such information, and how the cell system is regulated. As for catabolite regulation, F1,6B P (FDP, PEP, and PYR play important roles in enzyme level regulation together with transcriptional regulation by such transcription factors as Cra, Fis, CsrA, and cAMP-Crp. αKG plays an important role in the coordinated control between carbon (C- and nitrogen (N-limitations, where αKG inhibits enzyme I (EI of phosphotransferase system (PTS, thus regulating the glucose uptake rate in accordance with N level. As such, multiple regulation systems are co-ordinated for the cell synthesis and energy generation against nutrient limitations and environmental stresses. As for oxidative stress, the TCA cycle both generates and scavenges the reactive oxygen species (ROSs, where NADPH produced at ICDH and the oxidative pentose phosphate pathways play an important role in coping with oxidative stress. Solvent resistant mechanism was also considered for the stresses caused by biofuels and biochemicals production in the cell.

  15. Effect of Dietary Conjugated Linoleic Acid Supplementation on Early Inflammatory Responses during Cutaneous Wound Healing

    Directory of Open Access Journals (Sweden)

    Na-Young Park

    2010-01-01

    Full Text Available Inflammatory response is considered the most important period that regulates the entire healing process. Conjugated linoleic acid (CLA, a class of linoleic acid positional and geometric isomers, is well known for its antioxidant and anti-inflammatory properties. We hypothesized that dietary CLA supplementation accelerates cutaneous wound healing by regulating antioxidant and anti-inflammatory functions. To investigate wound closure rates and inflammatory responses, we used a full-thickness excisional wound model after 2-week treatments with control, 0.5%, or 1% CLA-supplemented diet. Mice fed dietary CLA supplementation had reduced levels of oxidative stress and inflammatory markers. Moreover, the wound closure rate was improved significantly in mice fed a 1% CLA-supplemented diet during early stage of wound healing (inflammatory stage. We conclude that dietary CLA supplementation enhances the early stage of cutaneous wound healing as a result of modulating oxidative stress and inflammatory responses.

  16. Transcriptomic Changes Drive Physiological Responses to Progressive Drought Stress and Rehydration in Tomato.

    Science.gov (United States)

    Iovieno, Paolo; Punzo, Paola; Guida, Gianpiero; Mistretta, Carmela; Van Oosten, Michael J; Nurcato, Roberta; Bostan, Hamed; Colantuono, Chiara; Costa, Antonello; Bagnaresi, Paolo; Chiusano, Maria L; Albrizio, Rossella; Giorio, Pasquale; Batelli, Giorgia; Grillo, Stefania

    2016-01-01

    Tomato is a major crop in the Mediterranean basin, where the cultivation in the open field is often vulnerable to drought. In order to adapt and survive to naturally occurring cycles of drought stress and recovery, plants employ a coordinated array of physiological, biochemical, and molecular responses. Transcriptomic studies on tomato responses to drought and subsequent recovery are few in number. As the search for novel traits to improve the genetic tolerance to drought increases, a better understanding of these responses is required. To address this need we designed a study in which we induced two cycles of prolonged drought stress and a single recovery by rewatering in tomato. In order to dissect the complexity of plant responses to drought, we analyzed the physiological responses (stomatal conductance, CO2 assimilation, and chlorophyll fluorescence), abscisic acid (ABA), and proline contents. In addition to the physiological and metabolite assays, we generated transcriptomes for multiple points during the stress and recovery cycles. Cluster analysis of differentially expressed genes (DEGs) between the conditions has revealed potential novel components in stress response. The observed reduction in leaf gas exchanges and efficiency of the photosystem PSII was concomitant with a general down-regulation of genes belonging to the photosynthesis, light harvesting, and photosystem I and II category induced by drought stress. Gene ontology (GO) categories such as cell proliferation and cell cycle were also significantly enriched in the down-regulated fraction of genes upon drought stress, which may contribute to explain the observed growth reduction. Several histone variants were also repressed during drought stress, indicating that chromatin associated processes are also affected by drought. As expected, ABA accumulated after prolonged water deficit, driving the observed enrichment of stress related GOs in the up-regulated gene fractions, which included transcripts

  17. TRANSCRIPTOMIC CHANGES DRIVE PHYSIOLOGICAL RESPONSES TO PROGRESSIVE DROUGHT STRESS AND REHYDRATION IN TOMATO

    Directory of Open Access Journals (Sweden)

    Paolo eIovieno

    2016-03-01

    Full Text Available Tomato is a major crop in the Mediterranean basin, where the cultivation in the open field is often vulnerable to drought. In order to adapt and survive to naturally occurring cycles of drought stress and recovery, plants employ a coordinated array of physiological, biochemical and molecular responses. Transcriptomic studies on tomato responses to drought and subsequent recovery are few in number. As the search for novel traits to improve the genetic tolerance to drought increases, a better understanding of these responses is required. To address this need we designed a study in which we induced two cycles of prolonged drought stress and a single recovery by rewatering in tomato. In order to dissect the complexity of plant responses to drought, we analyzed the physiological responses (stomatal conductance, CO2 assimilation and chlorophyll fluorescence, abscisic acid (ABA and proline contents. In addition to the physiological and metabolite assays, we generated transcriptomes for multiple points during the stress and recovery cycles. Cluster analysis of differentially expressed genes between the conditions has revealed potential novel components in stress response. The observed reduction in leaf gas exchanges and efficiency of the photosystem PSII was concomitant with a general down-regulation of genes belonging to the photosynthesis, light harvesting and photosystem I and II category induced by drought stress. Gene ontology (GO categories such as cell proliferation and cell cycle were also significantly enriched in the down-regulated fraction of genes upon drought stress, which may contribute to explain the observed growth reduction. Several histone variants were also repressed during drought stress, indicating that chromatin associated processes are also affected by drought. As expected, ABA accumulated after prolonged water deficit, driving the observed enrichment of stress related GOs in the up-regulated gene fractions, which included

  18. Gene Networks in Plant Ozone Stress Response and Tolerance

    Institute of Scientific and Technical Information of China (English)

    Agnieszka Ludwikow; Jan Sadowski

    2008-01-01

    For many plant species ozone stress has become much more severe in the last decade. The accumulating evidence for the significant effects of ozone pollutant on crop and forest yield situate ozone as one of the most important environmental stress factors that limits plant productivity woddwide. Today, transcdptomic approaches seem to give the best coverage of genome level responses. Therefore, microarray serves as an invaluable tool for global gene expression analyses, unravelling new information about gene pathways, in-species and crose-species gene expression comparison, and for the characterization of unknown relationships between genes. In this review we summadze the recent progress in the transcdptomics of ozone to demonstrate the benefits that can be harvested from the application of integrative and systematic analytical approaches to study ozone stress response. We focused our consideration on microarray analyses identifying gene networks responsible for response and tolerance to elevated ozone concentration. From these analyses it is now possible to notice how plant ozone defense responses depend on the interplay between many complex signaling pathways and metabolite signals.

  19. Transgenerational stress memory is not a general response in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Ales Pecinka

    Full Text Available Adverse conditions can trigger DNA damage as well as DNA repair responses in plants. A variety of stress factors are known to stimulate homologous recombination, the most accurate repair pathway, by increasing the concentration of necessary enzymatic components and the frequency of events. This effect has been reported to last into subsequent generations not exposed to the stress. To establish a basis for a genetic analysis of this transgenerational stress memory, a broad range of treatments was tested for quantitative effects on homologous recombination in the progeny. Several Arabidopsis lines, transgenic for well-established recombination traps, were exposed to 10 different physical and chemical stress treatments, and scored for the number of somatic homologous recombination (SHR events in the treated generation as well as in the two subsequent generations that were not treated. These numbers were related to the expression level of genes involved in homologous recombination and repair. SHR was enhanced after the majority of treatments, confirming previous data and adding new effective stress types, especially interference with chromatin. Compounds that directly modify DNA stimulated SHR to values exceeding previously described induction rates, concomitant with an induction of genes involved in SHR. In spite of the significant stimulation in the stressed generations, the two subsequent non-treated generations only showed a low and stochastic increase in SHR that did not correlate with the degree of stimulation in the parental plants. Transcripts coding for SHR enzymes generally returned to pre-treatment levels in the progeny. Thus, transgenerational effects on SHR frequency are not a general response to abiotic stress in Arabidopsis and may require special conditions.

  20. Ethylene is involved in stress responses induced by fusicoccin in sycamore cultured cells.

    Science.gov (United States)

    Malerba, Massimo; Crosti, Paolo; Cerana, Raffaella

    2010-11-15

    The phytohormone ethylene is involved in many physiological and developmental processes of plants, as well as in stress responses and in the development of disease resistance. Fusicoccin (FC) is a well-known phytotoxin, that in sycamore (Acer pseudoplatanus L.) cultured cells, induces a set of stress responses, including synthesis of ethylene. In this study, we investigated the possible involvement of ethylene in the FC-induced stress responses of sycamore cells by means of Co(2+), a well-known specific inhibitor of ethylene biosynthesis. Co(2+) inhibited the accumulation of dead cells in the culture, the production of nitric oxide (NO) and of the molecular chaperone Binding Protein (BiP) in the endoplasmic reticulum induced by FC. By contrast, Co(2+) was ineffective on the FC-induced accumulation of cells with fragmented DNA, production of H(2)O(2) and release of cytochrome c from the mitochondrion, and only partially reduced the accumulation of regulative 14-3-3 proteins in the cytosol. In addition, we compared the effect of FC on the above parameters with that of the ethylene-releasing compound ethephon (2-chloroethane phosphonic acid). The results suggest that ethylene is involved in several stress responses induced by FC in sycamore cells, including a form of cell death that does not show apoptotic features and possibly involves NO as a signaling molecule.

  1. Regulation of abiotic and biotic stress responses by plant hormones

    DEFF Research Database (Denmark)

    Grosskinsky, Dominik Kilian; van der Graaff, Eric; Roitsch, Thomas Georg

    2016-01-01

    Plant hormones (phytohormones) are signal molecules produced within the plant, and occur in very low concentrations. In the present chapter, the current knowledge on the regulation of biotic and biotic stress responses by plant hormones is summarized with special focus on the novel insights...... through ubiquitination. The wide range of biotic and abiotic stresses that affect crop plants limits agricultural production....... into the complex hormonal crosstalk of classical growth stimulating plant hormones within the naturally occurring biotic and abiotic multistress environment of higher plants. The MAPK- and phytohormone-cascades which comprise a multitude of single molecules on different signalling levels, as well as interactions...

  2. Molecular Responses of Groundnut (Arachis hypogea L. to Zinc Stress

    Directory of Open Access Journals (Sweden)

    A. John De Britto

    2013-08-01

    Full Text Available Heavy metals are important environmental pollutants and their toxicity is a problem of increasing significance for ecological, evolutionary and environmental reasons. The interference of germination related proteins by heavy metals has not been well documented at the proteomic and genomic level. In the current study, molecular responses of germinating groundnut seeds were investigated under Zinc stress. The SDS-PAGE showed the preliminary changes in the polypeptides patterns under Zinc stress. Restriction digestion banding pattern of EcoRI and Hind III enzymes showed distinct banding pattern in the treated plants.

  3. Family business: multiple members of major phytohormone classes orchestrate plant stress responses.

    Science.gov (United States)

    Erb, Matthias; Glauser, Gaetan

    2010-09-10

    Low-molecular-weight compounds such as jasmonic, abscisic and salicylic acids are commonly thought to be regulators of plant stress responses. However, it is becoming clear that these molecules, often referred to as phytohormones, are only a part of bigger groups of compounds with biological activity. We propose that the concept of "hormone families" may help to better understand plant physiological responses by taking into account not only the alleged main regulators, but also their precursors, conjugates and catabolites. Novel approaches to profile potentially active compounds in plants are discussed. PMID:20648494

  4. Mechanical stress induces neuroendocrine and immune responses of sea cucumber ( Apostichopus japonicus)

    Science.gov (United States)

    Tan, Jie; Li, Fenghui; Sun, Huiling; Gao, Fei; Yan, Jingping; Gai, Chunlei; Chen, Aihua; Wang, Qingyin

    2015-04-01

    Grading procedure in routine sea cucumber hatchery production is thought to affect juvenile sea cucumber immunological response. The present study investigated the impact of a 3-min mechanical perturbation mimicking the grading procedure on neuroendocrine and immune parameters of the sea cucumber Apostichopus japonicus. During the application of stress, concentrations of noradrenaline and dopamine in coelomic fluid increased significantly, indicating that the mechanical perturbation resulted in a transient state of stress in sea cucumbers. Coelomocytes concentration in coelomic fluid increased transiently after the beginning of stressing, and reached the maximum in 1 h. Whereas, coelomocytes phagocytosis at 3 min, superoxide anion production from 3 min to 0.5 h, acid phosphatase activity at 0.5 h, and phenoloxidase activity from 3 min to 0.5 h were all significantly down-regulated. All of the immune parameters recovered to baseline levels after the experiment was conducted for 8 h, and an immunostimulation occurred after the stress considering the phagocytosis and acid phosphatase activity. The results suggested that, as in other marine invertebrates, neuroendocrine/immune connections exist in sea cucumber A. japonicus. Mechanical stress can elicit a profound influence on sea cucumber neuroendocrine system. Neuroendocrine messengers act in turn to modulate the immunity functions. Therefore, these effects should be considered for developing better husbandry procedures.

  5. Listeria ivanovii ATCC 19119 strain behaviour is modulated by iron and acid stress.

    Science.gov (United States)

    Longhi, Catia; Ammendolia, Maria Grazia; Conte, Maria Pia; Seganti, Lucilla; Iosi, Francesca; Superti, Fabiana

    2014-09-01

    It has been suggested that the rarity of human listeriosis due to Listeria ivanovii reflects not only host tropism factors but also the rare occurrence of this species in the environment, compared with Listeria monocytogenes. In the present study we evaluate the effects on the reference strain L. ivanovii ATCC 19119 behaviour of two combined stresses, low iron availability and acid environment, that bacteria can encounter in the passage from saprophytic life to the host. In these conditions, L. ivanovii evidenced a different behaviour compared to L. monocytogenes exposed to similar conditions. L. ivanovii was not able to mount an acid tolerance response (ATR) even if, upon entry into the stationary phase in iron-loaded medium, growth phase-dependent acid resistance (AR) was evidenced. Moreover, bacteria grown in iron excess and acidic pH showed the higher invasion value in Caco-2 cells, even though it was not able to efficiently multiply. On the contrary, low iron and acidic conditions improved invasion ability in amniotic WISH cells.

  6. Stability of sublethal acid stress adaptaion and induced cross protection against lauric arginate in Listeria monocytogenes

    Science.gov (United States)

    The stability of acid stress adaptation in Listeria monocytogenes and its induced cross protection effect against GRAS (generally recognized as safe) antimicrobial compounds has never been investigated before. In the present study, the acid stress adaptation in L. monocytogenes was initially induced...

  7. Influence of temperature on acid-stress adaptation in Listeria monocytogenes

    Science.gov (United States)

    Several factors play critical roles in controlling the induction of acid-stress adaptation in L. monocytogenes. Our findings show that temperature plays a significant role in the induction of acid-stress adaptation in Listeria monocytogenes and two distinct patterns were observed: (I) Presence of su...

  8. Mongolian Almond (Prunus mongolica Maxim): The Morpho-Physiological, Biochemical and Transcriptomic Response to Drought Stress.

    Science.gov (United States)

    Wang, Jǖgang; Zheng, Rong; Bai, Shulan; Gao, Xiaomin; Liu, Min; Yan, Wei

    2015-01-01

    Prunus mongolica Maxim, which is widely established in the Gobi Desert, shows extreme tolerance to drought. However, there is a lack of available transcriptomic resources for this species related to its response to water deficiency. To investigate the mechanisms that allow P. mongolica to maintain growth in extremely arid environments, the response of P. mongolica seedlings to drought stress was analyzed using morphological, physiological, biochemical and high-throughput sequencing approaches. We generated 28,713,735 and 26,650,133 raw reads from no-stress control and drought-stressed P. mongolica seedlings, respectively. In total, we obtained 67,352 transcripts with an average length of 874.44 bp. Compared with the no-stress control, 3,365 transcripts were differentially expressed in the drought-stressed seedlings, including 55.75% (1,876 transcripts) up-regulated and 44.25% (1,489 transcripts) down-regulated transcripts. The photosynthesis response showed a decreasing tendency under drought stress, but the changes in the levels of hormones (auxins, cytokinins and abscisic acid) resulted in the closing of stomata and decreased cell enlargement and division; these changes were effective for promoting P. mongolica survival in Gobi Desert. Next, we analyzed the aquaporin and superoxide dismutase gene families due to their importance in plant resistance to drought stress. We found that all of the plasma membrane intrinsic protein transcripts were down-regulated in the drought-stressed treatment, whereas drought did not affect the expression of nodulin intrinsic protein or small basic intrinsic protein transcripts in P. mongolica seedlings. In addition, activation of iron superoxide dismutase transcription and enhanced transcription of manganese superoxide dismutase were observed in P. mongolica to promote tolerance of drought stress. This study identified drought response genes in P. mongolica seedlings. Our results provide a significant contribution to the

  9. Mongolian Almond (Prunus mongolica Maxim: The Morpho-Physiological, Biochemical and Transcriptomic Response to Drought Stress.

    Directory of Open Access Journals (Sweden)

    Jǖgang Wang

    Full Text Available Prunus mongolica Maxim, which is widely established in the Gobi Desert, shows extreme tolerance to drought. However, there is a lack of available transcriptomic resources for this species related to its response to water deficiency. To investigate the mechanisms that allow P. mongolica to maintain growth in extremely arid environments, the response of P. mongolica seedlings to drought stress was analyzed using morphological, physiological, biochemical and high-throughput sequencing approaches. We generated 28,713,735 and 26,650,133 raw reads from no-stress control and drought-stressed P. mongolica seedlings, respectively. In total, we obtained 67,352 transcripts with an average length of 874.44 bp. Compared with the no-stress control, 3,365 transcripts were differentially expressed in the drought-stressed seedlings, including 55.75% (1,876 transcripts up-regulated and 44.25% (1,489 transcripts down-regulated transcripts. The photosynthesis response showed a decreasing tendency under drought stress, but the changes in the levels of hormones (auxins, cytokinins and abscisic acid resulted in the closing of stomata and decreased cell enlargement and division; these changes were effective for promoting P. mongolica survival in Gobi Desert. Next, we analyzed the aquaporin and superoxide dismutase gene families due to their importance in plant resistance to drought stress. We found that all of the plasma membrane intrinsic protein transcripts were down-regulated in the drought-stressed treatment, whereas drought did not affect the expression of nodulin intrinsic protein or small basic intrinsic protein transcripts in P. mongolica seedlings. In addition, activation of iron superoxide dismutase transcription and enhanced transcription of manganese superoxide dismutase were observed in P. mongolica to promote tolerance of drought stress. This study identified drought response genes in P. mongolica seedlings. Our results provide a significant contribution

  10. Calcium affecting protein expression in longan under simulated acid rain stress.

    Science.gov (United States)

    Pan, Tengfei; Li, Yongyu; Ma, Cuilan; Qiu, Dongliang

    2015-08-01

    Longan (Dimocarpus longana Lour. cv. Wulongling) of uniform one-aged seedlings grown in pots were selected to study specific proteins expressed in leaves under simulated acid rain (SiAR) stress and exogenous Ca(2+) regulation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results showed that there was a protein band specifically expressed under SiAR of pH 2.5 stress for 15 days with its molecular weight of about 23 kD. A 17 kD protein band specifically expressed after SiAR stress 5 days. Compared with pH 2.5, the pH 3.5 of SiAR made a less influence to protein expression. Two-dimensional electrophoresis (2-DE) results showed that six new specific proteins including C4 (20.2 kD pI 6.0), F (24 kD pI 6.35), B3 (22.3 kD pI 6.35), B4 (23.5 kD pI 6.5), C5 (21.8 kD pI 5.6), and C6 (20.2 kD pI 5.6) specifically expressed. C4 always expressed during SiAR stress. F expressed under the stress of pH 2.5 for 15 days and expressed in all pH SiAR stress for 20 days. The expression of proteins including B3, C5, and C6 was related to pH value and stress intensity of SiAR. The expression of B4 resulted from synergistic effects of SiAR and Ca. The expression of G1 (Mr 19.3 kD, pI 4.5), G2 (Mr 17.8 kD, pI 4.65), G3 (Mr 16.6 kD, pI 4.6), and G4 (Mr 14.7 kD, pI 4.4) enhanced under the treatment of 5 mM ethylene glycol tetraacetic acid (EGTA) and 2 mM chlorpromazine (CPZ). These proteins showed antagonistic effects and might be relative to the Ca-calmodulin (Ca-CaM) system of longan in response to SiAR stress. PMID:25893616

  11. Ethylene Response Factor Sl-ERF.B.3 Is Responsive to Abiotic Stresses and Mediates Salt and Cold Stress Response Regulation in Tomato

    Directory of Open Access Journals (Sweden)

    Imen Klay

    2014-01-01

    Full Text Available Sl-ERF.B.3 (Solanum lycopersicum ethylene response factor B.3 gene encodes for a tomato transcription factor of the ERF (ethylene responsive factor family. Our results of real-time RT-PCR showed that Sl-ERF.B.3 is an abiotic stress responsive gene, which is induced by cold, heat, and flooding, but downregulated by salinity and drought. To get more insight into the role of Sl-ERF.B.3 in plant response to separate salinity and cold, a comparative study between wild type and two Sl-ERF.B.3 antisense transgenic tomato lines was achieved. Compared with wild type, Sl-ERF.B.3 antisense transgenic plants exhibited a salt stress dependent growth inhibition. This inhibition was significantly enhanced in shoots but reduced in roots, leading to an increased root to shoot ratio. Furthermore, the cold stress essay clearly revealed that introducing antisense Sl-ERF.B.3 in transgenic tomato plants reduces their cell injury and enhances their tolerance against 14 d of cold stress. All these results suggest that Sl-ERF.B.3 gene is involved in plant response to abiotic stresses and may play a role in the layout of stress symptoms under cold stress and in growth regulation under salinity.

  12. Ethylene response factor Sl-ERF.B.3 is responsive to abiotic stresses and mediates salt and cold stress response regulation in tomato.

    Science.gov (United States)

    Klay, Imen; Pirrello, Julien; Riahi, Leila; Bernadac, Anne; Cherif, Ameur; Bouzayen, Mondher; Bouzid, Sadok

    2014-01-01

    Sl-ERF.B.3 (Solanum lycopersicum ethylene response factor B.3) gene encodes for a tomato transcription factor of the ERF (ethylene responsive factor) family. Our results of real-time RT-PCR showed that Sl-ERF.B.3 is an abiotic stress responsive gene, which is induced by cold, heat, and flooding, but downregulated by salinity and drought. To get more insight into the role of Sl-ERF.B.3 in plant response to separate salinity and cold, a comparative study between wild type and two Sl-ERF.B.3 antisense transgenic tomato lines was achieved. Compared with wild type, Sl-ERF.B.3 antisense transgenic plants exhibited a salt stress dependent growth inhibition. This inhibition was significantly enhanced in shoots but reduced in roots, leading to an increased root to shoot ratio. Furthermore, the cold stress essay clearly revealed that introducing antisense Sl-ERF.B.3 in transgenic tomato plants reduces their cell injury and enhances their tolerance against 14 d of cold stress. All these results suggest that Sl-ERF.B.3 gene is involved in plant response to abiotic stresses and may play a role in the layout of stress symptoms under cold stress and in growth regulation under salinity. PMID:25215313

  13. Proteomic response of wheat embryos to fosthiazate stress in a protected vegetable soil

    Institute of Scientific and Technical Information of China (English)

    Chunyan Yin; Ying Teng; Yongming Luo; Peter Christie

    2012-01-01

    A proteomic analysis of wheat defense response induced by the widely used organophosphorus nematicide fosthiazate is reported.Seed germination and two-dimensional gel electrophoresis (2-DE) experiments were performed using a Chinese wheat cultivar,Zhenmai No.5.Root and shoot elongation decreased but thiobarbituric acid reactive substances (TBARS) content in embryos increased with increasing pesticide concentration.More than 1000 protein spots were reproducibly detected in each silver-stained gel.Thirty-seven protein spots with at least 2-fold changes were identified using MALDI-TOF MS/MS analysis.Of these,24 spots were up-regulated and 13 were down-regulated.Proteins identified included some well-known classical stress responsive proteins under abiotic or biotic stresses as well as some unusual responsive proteins.Ten responsive proteins were reported for the first time at the proteomic level,including fatty acyl CoA reductase,dihydrodipicolinate synthase,DEAD-box ATPase-RNA-helicase,fimbriata-like protein,waxy B1,rust resistance kinase Lrl0,putative In2.1 protein,retinoblastoma-related protein 1,pollen allergen-like protein and S-adenosyl-Lmethionine:phosphoethanolamine N-methyltransferase.The proteins identified were involved in several processes such as metabolism,defense/detoxification,cell structure/cell growth,signal transduction/transcription,photosynthesis and energy.Seven candidate proteins were further analyzed at the mRNA level by RT-PCR to compare transcript and protein accumulation patterns,revealing that not all the genes were correlated well with the protein level.Identification of these responsive proteins may provide new insight into the molecular basis of the fosthiazate-stress response in the early developmental stages of plants and may be useful in stress monitoring or stress-tolerant crop breeding for environmentally friendly agricultural production.

  14. Stress responses from the endoplasmic reticulum in cancer

    Directory of Open Access Journals (Sweden)

    Hironori eKato

    2015-04-01

    Full Text Available The endoplasmic reticulum (ER is a dynamic organelle that is essential for multiple cellular functions. During cellular stress conditions, including nutrient deprivation and dysregulation of protein synthesis, unfolded/misfolded proteins accumulate in the ER lumen, resulting in activation of the unfolded protein response (UPR. The UPR also contributes to the regulation of various intracellular signalling pathways such as calcium signalling and lipid signalling. More recently, the mitochondria-associated ER membrane (MAM, which is a site of close contact between the ER and mitochondria, has been shown to function as a platform for various intracellular stress responses including apoptotic signalling, inflammatory signalling, the autophagic response, and the UPR. Interestingly, in cancer, these signalling pathways from the ER are often dysregulated, contributing to cancer cell metabolism. Thus, the signalling pathway from the ER may be a novel therapeutic target for various cancers. In this review, we discuss recent research on the roles of stress responses from the ER, including the MAM.

  15. Transcriptome Analysis of Spartina pectinata in Response to Freezing Stress.

    Science.gov (United States)

    Nah, Gyoungju; Lee, Moonsub; Kim, Do-Soon; Rayburn, A Lane; Voigt, Thomas; Lee, D K

    2016-01-01

    Prairie cordgrass (Spartina pectinata), a perennial C4 grass native to the North American prairie, has several distinctive characteristics that potentially make it a model crop for production in stressful environments. However, little is known about the transcriptome dynamics of prairie cordgrass despite its unique freezing stress tolerance. Therefore, the purpose of this work was to explore the transcriptome dynamics of prairie cordgrass in response to freezing stress at -5°C for 5 min and 30 min. We used a RNA-sequencing method to assemble the S. pectinata leaf transcriptome and performed gene-expression profiling of the transcripts under freezing treatment. Six differentially expressed gene (DEG) groups were categorized from the profiling. In addition, two major consecutive orders of gene expression were observed in response to freezing; the first being the acute up-regulation of genes involved in plasma membrane modification, calcium-mediated signaling, proteasome-related proteins, and transcription regulators (e.g., MYB and WRKY). The follow-up and second response was of genes involved in encoding the putative anti-freezing protein and the previously known DNA and cell-damage-repair proteins. Moreover, we identified the genes involved in epigenetic regulation and circadian-clock expression. Our results indicate that freezing response in S. pectinata reflects dynamic changes in rapid-time duration, as well as in metabolic, transcriptional, post-translational, and epigenetic regulation. PMID:27032112

  16. EFFECT OF SALICYLIC ACID AND ASCORBIC ACID ON GERMINATION INDEXES AND ENZYME ACTIVITY OF SORGHUM SEEDS UNDER DROUGHT STRESS

    OpenAIRE

    Tabatabaei S. A.

    2013-01-01

    Seed priming methods have been used to increase germination characteristics under stress conditions. The effects of drought stress (0, -4, -8, -12 and -16 bar) and salicylic acid 25 ppm at 15 °C for 15 h and ascorbic acid 25 ppm at 15 °C for 15 h on germination percentage, germination index, means time to germination, normal seedling percentage and enzyme activity were assessed in the laboratory for sorghum seeds (Sorghum bicolor L.). Results showed that the ...

  17. A simple melatonin treatment protocol attenuates the response to acute stress in the sole Solea senegalensis

    DEFF Research Database (Denmark)

    Gesto, Manuel; Álvarez-Otero, Rosa; Conde-Sieira, Marta;

    2016-01-01

    Several compounds have been tested in fish in order to attenuate the effects of different stressors, most often following previous observations in mammals. The hormone melatonin (MEL) and the amino acid L-tryptophan have been tested for this purpose with different degree of success. In Senegalese...... sole (Solea senegalensis) we have previously observed that during prolonged exposure to relatively mild stressors, the presence of MEL in the water helped to reduce the stress response. Here, we aimed to investigate the potential anti-stress effects of a short melatonin exposure that could be easily...... in Senegalese sole. In view of the observed anti-stress effects of MEL, further research is warranted in order to optimize doses and timing of application to improve the effectiveness of the MEL treatment for aquaculture purposes....

  18. Characterization of the physiological stress response in lingcod

    Science.gov (United States)

    Milston, R.H.; Davis, M.W.; Parker, S.J.; Olla, B.L.; Clements, S.; Schreck, C.B.

    2006-01-01

    The goal of this study was to describe the duration and magnitude of the physiological stress response in lingcod Ophiodon elongatus after exposure to brief handling and sublethal air stressors. The response to these stressors was determined during a 24-h recovery period by measuring concentrations of plasma cortisol, lactate, glucose, sodium, and potassium. Lingcod were subjected to brief handling followed by either a 15-min or a 45-min air stressor in the laboratory. After the 15-min stressor, an increase in cortisol or glucose could not be detected until after 5 min of recovery. Peak concentrations were measured after 30 min for cortisol and after 60 min for glucose and lactate. Glucose and lactate had returned to basal levels after 12 h, whereas cortisol did not return to basal levels until after 24 h of recovery. Immediately following a 45-min air stressor, all measured parameters were significantly elevated over levels in prestressor control fish. Cortisol concentrations tended to increase and reached a measured peak after 8 h of recovery, whereas glucose and lactate reached a measured peak after 1 h of recovery. Cortisol and lactate returned to basal levels within 24 h. Glucose, however, remained elevated even after 24 h of recovery. Plasma ions initially increased during the first hour of recovery, and the concentrations then declined to a level below that measured in control fish for the remainder of the 24-h recovery period. In addition, we evaluated the effect of fish size on the stress response. There was no significant difference between the stress response of smaller (41-49-cm [total length] and larger (50-67-cm) lingcod after 45 min air exposure. In general, both the magnitude and duration of the primary and secondary stress responses in lingcod are comparable to those of salmonids. ?? Copyright by the American Fisheries Society 2006.

  19. Deciphering hepatocellular responses to metabolic and oncogenic stress

    Directory of Open Access Journals (Sweden)

    Kathrina L. Marcelo

    2015-08-01

    Full Text Available Each cell type responds uniquely to stress and fractionally contributes to global and tissue-specific stress responses. Hepatocytes, liver macrophages (MΦ, and sinusoidal endothelial cells (SEC play functionally important and interdependent roles in adaptive processes such as obesity and tumor growth. Although these cell types demonstrate significant phenotypic and functional heterogeneity, their distinctions enabling disease-specific responses remain understudied. We developed a strategy for the simultaneous isolation and quantification of these liver cell types based on antigenic cell surface marker expression. To demonstrate the utility and applicability of this technique, we quantified liver cell-specific responses to high-fat diet (HFD or diethylnitrosamine (DEN, a liver-specific carcinogen, and found that while there was only a marginal increase in hepatocyte number, MΦ and SEC populations were quantitatively increased. Global gene expression profiling of hepatocytes, MΦ and SEC identified characteristic gene signatures that define each cell type in their distinct physiological or pathological states. Integration of hepatic gene signatures with available human obesity and liver cancer microarray data provides further insight into the cell-specific responses to metabolic or oncogenic stress. Our data reveal unique gene expression patterns that serve as molecular “fingerprints” for the cell-centric responses to pathologic stimuli in the distinct microenvironment of the liver. The technical advance highlighted in this study provides an essential resource for assessing hepatic cell-specific contributions to metabolic and oncogenic stress, information that could unveil previously unappreciated molecular mechanisms for the cellular crosstalk that underlies the continuum from metabolic disruption to obesity and ultimately hepatic cancer.

  20. EFFECT OF DEXMEDETOMIDINE ON STRESS RESPONSE TO ENDOTRACHEAL INTUBATION

    Directory of Open Access Journals (Sweden)

    Sathee Devi

    2015-03-01

    Full Text Available Laryngoscopy as well as tracheal intubation cause changes in the hemodynamics of the patients. A similar set of hemodynamic events have been noticed by various studies during tracheal extubation also. These responses may produce myocardial ischemia or infarction in susceptible patients. Various agents like lignocaine, e smolol, sodium nitropruside, nitroglycerine etc . have been proved to be effective in attenuating these response. Dexmedetomidine, an alpha 2 agonist have been successfully used for attenuating the sympathetic response during endotracheal extubation. We conducted an observational study to examine the rol e of dexmedetomidine on hemodynamic response during endotracheal intubation. A bolus dose of Dexmedetomidine 0.7 - 1 mcg /kg over 10mts prior to endotracheal intubation provided hemodynamic stability than inj. lignocaine hydrochloride ( G old standard .This c an prove beneficial for patients where the stress response to intubation is highly undesirable.

  1. Brain 5-HT deficiency increases stress vulnerability and impairs antidepressant responses following psychosocial stress.

    Science.gov (United States)

    Sachs, Benjamin D; Ni, Jason R; Caron, Marc G

    2015-02-24

    Brain serotonin (5-HT) deficiency and exposure to psychosocial stress have both been implicated in the etiology of depression and anxiety disorders, but whether 5-HT deficiency influences susceptibility to depression- and anxiety-like phenotypes induced by psychosocial stress has not been formally established. Most clinically effective antidepressants increase the extracellular levels of 5-HT, and thus it has been hypothesized that antidepressant responses result from the reversal of endogenous 5-HT deficiency, but this hypothesis remains highly controversial. Here we evaluated the impact of brain 5-HT deficiency on stress susceptibility and antidepressant-like responses using tryptophan hydroxylase 2 knockin (Tph2KI) mice, which display 60-80% reductions in brain 5-HT. Our results demonstrate that 5-HT deficiency leads to increased susceptibility to social defeat stress (SDS), a model of psychosocial stress, and prevents the fluoxetine (FLX)-induced reversal of SDS-induced social avoidance, suggesting that 5-HT deficiency may impair antidepressant responses. In light of recent clinical and preclinical studies highlighting the potential of inhibiting the lateral habenula (LHb) to achieve antidepressant and antidepressant-like responses, we also examined whether LHb inhibition could achieve antidepressant-like responses in FLX-insensitive Tph2KI mice subjected to SDS. Our data reveal that using designer receptors exclusively activated by designer drugs (DREADDs) to inhibit LHb activity leads to reduced SDS-induced social avoidance behavior in both WT and Tph2KI mice. This observation provides additional preclinical evidence that inhibiting the LHb might represent a promising alternative therapeutic approach under conditions in which selective 5-HT reuptake inhibitors are ineffective.

  2. The cellular response to curvature-induced stress

    Science.gov (United States)

    Biton, Y. Y.; Safran, S. A.

    2009-12-01

    We present a theoretical model to explain recent observations of the orientational response of cells to unidirectional curvature. Experiments show that some cell types when plated on a rigid cylindrical surface tend to reorient their shape and stress fibers along the axis of the cylinder, while others align their stress fibers perpendicular to that axis. Our model focuses on the competition of the shear stress—that results from cell adhesion and active contractility—and the anisotropic bending stiffness of the stress fibers. We predict the cell orientation angle that results from the balance of these two forces in a mechanical equilibrium. The conditions under which the different experimental observations can be obtained are discussed in terms of the theory.

  3. Quorum sensing regulates the osmotic stress response in Vibrio harveyi.

    Science.gov (United States)

    van Kessel, Julia C; Rutherford, Steven T; Cong, Jian-Ping; Quinodoz, Sofia; Healy, James; Bassler, Bonnie L

    2015-01-01

    Bacteria use a chemical communication process called quorum sensing to monitor cell density and to alter behavior in response to fluctuations in population numbers. Previous studies with Vibrio harveyi have shown that LuxR, the master quorum-sensing regulator, activates and represses >600 genes. These include six genes that encode homologs of the Escherichia coli Bet and ProU systems for synthesis and transport, respectively, of glycine betaine, an osmoprotectant used during osmotic stress. Here we show that LuxR activates expression of the glycine betaine operon betIBA-proXWV, which enhances growth recovery under osmotic stress conditions. BetI, an autorepressor of the V. harveyi betIBA-proXWV operon, activates the expression of genes encoding regulatory small RNAs that control quorum-sensing transitions. Connecting quorum-sensing and glycine betaine pathways presumably enables V. harveyi to tune its execution of collective behaviors to its tolerance to stress.

  4. The plant response:stress in the daily environment

    Institute of Scientific and Technical Information of China (English)

    FERGUSON Ian B.

    2004-01-01

    @@STRESS IS NORMAL Like animals, plants have evolved to survive in almost every climatic and environmental niche available. They have, however, evolved more sophisticated and varied methods to enable them to survive environmental changes in light, temperature, atmosphere composition, water and nutrients and salinity. This, in part, is necessary because of the sessile nature of plants; they do not have the ability to move to more favourable environments. Stress conditions that plants encounter are not always as rare or unusual as we might at first think. The most common environmental variables, necessary for growth, can impose significant stresses on the plant. But should we think of these as unusual and extreme or just part of the normal diurnal responses experienced by the plant?

  5. Relative gene transcription and pathogenicity of enterohemorrhagic Escherichia coli after long-term adaptation to acid and salt stress

    DEFF Research Database (Denmark)

    Olesen, Inger; Jespersen, Lene

    2010-01-01

    Relative gene transcription and virulence potential, as measured by a Caco-2 adhesion assay, were investigated for three enterohemorrhagic Escherichia coli (EHEC) strains after long-term adaptation for 24 h to acid (BHI pH 5.5) and salt (BHI 4.5% (w/v) NaCl) stress. Five virulence genes (eae, lpf......A, stx1A, stx2A and tir) and three stress response genes (asr, gadA and rpoS) were selected for gene transcription studies and compared to the relative transcription after growth at standard condition (BHI pH 7.0). In general, long-term adaptation to acid and salt stress significantly repressed...... compared to EDL933 (O157:H7, raw hamburger). Long-term adaptation to salt stress significantly increased the adhesion of all three EHEC strains to Caco-2 compared to the non-stressed controls. The present study shows that long-term adaptation to food related stress factors such as acid and salt is capable...

  6. Release of brain amino acids during hyposmolar stress and energy deprivation.

    Science.gov (United States)

    Haugstad, T S; Langmoen, I A

    1996-04-01

    The release of 10 amino acids from rat hippocampal slices during exposure to hyposmotic stress or energy deprivation was measured by high-performance liquid chromatography. Exposing the slices to hyposmotic stress by lowering extracellular NaCl caused a 10-fold release of taurine (p alanine release (p isoelectric point) and hydropathy indexes. Energy deprivation increased the permissivity in the following order: acidic > neutral > basic. Among neutral amino acids, permissivity increased with increasing hydrophobicity. These results indicate that the mechanisms of amino acid release are different during cerebral ischemia and hyposmotic stress. PMID:8829565

  7. Insights into Vibrio parahaemolyticus CHN25 Response to Artificial Gastric Fluid Stress by Transcriptomic Analysis

    Directory of Open Access Journals (Sweden)

    Xuejiao Sun

    2014-12-01

    Full Text Available Vibrio parahaemolyticus is the causative agent of food-borne gastroenteritis disease. Once consumed, human acid gastric fluid is perhaps one of the most important environmental stresses imposed on the bacterium. Herein, for the first time, we investigated Vibrio parahaemolyticus CHN25 response to artificial gastric fluid (AGF stress by transcriptomic analysis. The bacterium at logarithmic growth phase (LGP displayed lower survival rates than that at stationary growth phase (SGP under a sub-lethal acid condition (pH 4.9. Transcriptome data revealed that 11.6% of the expressed genes in Vibrio parahaemolyticus CHN25 was up-regulated in LGP cells after exposed to AGF (pH 4.9 for 30 min, including those involved in sugar transport, nitrogen metabolism, energy production and protein biosynthesis, whereas 14.0% of the genes was down-regulated, such as ATP-binding cassette (ABC transporter and flagellar biosynthesis genes. In contrast, the AGF stress only elicited 3.4% of the genes from SGP cells, the majority of which were attenuated in expression. Moreover, the number of expressed regulator genes was also substantially reduced in SGP cells. Comparison of transcriptome profiles further revealed forty-one growth-phase independent genes in the AGF stress, however, half of which displayed distinct expression features between the two growth phases. Vibrio parahaemolyticus seemed to have evolved a number of molecular strategies for coping with the acid stress. The data here will facilitate future studies for environmental stresses and pathogenicity of the leading seafood-borne pathogen worldwide.

  8. CYP2J2-Derived Epoxyeicosatrienoic Acids Suppress Endoplasmic Reticulum Stress in Heart Failure

    OpenAIRE

    Wang, Xingxu; Ni, Li; Yang, Lei; Duan, Quanlu; Chen, Chen; Edin, Matthew L.; Zeldin, Darryl C.; WANG, DAO WEN

    2014-01-01

    Prolonged endoplasmic reticulum (ER) stress causes apoptosis and is associated with heart failure. Whether CYP2J2 and its arachidonic acid metabolites [epoxyeicosatrienoic acids (EETs)] have a protective influence on ER stress and heart failure has not been studied. Assays of myocardial samples from patients with end-stage heart failure showed evidence of ER stress. Chronic infusion of isoproterenol (ISO) or angiotensin II (AngII) by osmotic mini-pump induced cardiac hypertrophy and heart fai...

  9. Integrated stress response of vertebrates is regulated by four eIF2α kinases

    Science.gov (United States)

    Taniuchi, Shusuke; Miyake, Masato; Tsugawa, Kazue; Oyadomari, Miho; Oyadomari, Seiichi

    2016-01-01

    The integrated stress response (ISR) is a cytoprotective pathway initiated upon phosphorylation of the eukaryotic translation initiation factor 2 (eIF2α) residue designated serine-51, which is critical for translational control in response to various stress conditions. Four eIF2α kinases, namely heme-regulated inhibitor (HRI), protein kinase R (PKR), PKR-like endoplasmic reticulum kinase, (PERK) and general control non-depressible 2 (GCN2), have been identified thus far, and they are known to be activated by heme depletion, viral infection, endoplasmic reticulum stress, and amino acid starvation, respectively. Because eIF2α is phosphorylated under various stress conditions, the existence of an additional eIF2α kinase has been suggested. To validate the existence of the unidentified eIF2α kinase, we constructed an eIF2α kinase quadruple knockout cells (4KO cells) in which the four known eIF2α kinase genes were deleted using the CRISPR/Cas9-mediated genome editing. Phosphorylation of eIF2α was completely abolished in the 4KO cells by various stress stimulations. Our data suggests that the four known eIF2α kinases are sufficient for ISR and that there are no additional eIF2α kinases in vertebrates. PMID:27633668

  10. Integrated stress response of vertebrates is regulated by four eIF2α kinases.

    Science.gov (United States)

    Taniuchi, Shusuke; Miyake, Masato; Tsugawa, Kazue; Oyadomari, Miho; Oyadomari, Seiichi

    2016-01-01

    The integrated stress response (ISR) is a cytoprotective pathway initiated upon phosphorylation of the eukaryotic translation initiation factor 2 (eIF2α) residue designated serine-51, which is critical for translational control in response to various stress conditions. Four eIF2α kinases, namely heme-regulated inhibitor (HRI), protein kinase R (PKR), PKR-like endoplasmic reticulum kinase, (PERK) and general control non-depressible 2 (GCN2), have been identified thus far, and they are known to be activated by heme depletion, viral infection, endoplasmic reticulum stress, and amino acid starvation, respectively. Because eIF2α is phosphorylated under various stress conditions, the existence of an additional eIF2α kinase has been suggested. To validate the existence of the unidentified eIF2α kinase, we constructed an eIF2α kinase quadruple knockout cells (4KO cells) in which the four known eIF2α kinase genes were deleted using the CRISPR/Cas9-mediated genome editing. Phosphorylation of eIF2α was completely abolished in the 4KO cells by various stress stimulations. Our data suggests that the four known eIF2α kinases are sufficient for ISR and that there are no additional eIF2α kinases in vertebrates. PMID:27633668

  11. Transcriptional Analysis of Normal Human Fibroblast Responses to Microgravity Stress

    Institute of Scientific and Technical Information of China (English)

    Yongqing Liu; Eugenia Wang

    2008-01-01

    To understand the molecular mechanism (s) of how spaceflight affects cellular signaling pathways, quiescent normal human WI-38 fibroblasts were flown on the STS-93 space shuttle mission. Subsequently, RNA samples from the space flown and ground-control cells were used to construct two cDNA libraries, which were then processed for suppression subtractive hybridization (SSH) to identify spaceflight-specific gene expression. The SSH data show that key genes related to oxidative stress, DNA repair, and fatty acid oxidation are activated by spaceflight, suggesting the induction of cellular oxidative stress. This is further substantiated by the up-regulation of neuregulin 1 and the calcium-binding protein calmodulin 2. Another obvious stress sign is that spaceflight evokes the Ras/mitogen-activated protein kinase and phosphatidylinositol-3 kinase signaling pathways, along with up-regulating several G1-phase cell cycle traverse genes. Other genes showing up regulation of expression are involved in protein synthesis and pro-apoptosis, as well as pro-survival. Interactome analysis of functionally related genes shows that c-Myc is the "hub" for those genes showing significant changes. Hence, our results suggest that microgravity travel may impact changes in gene expression mostly associated with cellular stress signaling, directing cells to either apoptotic death or premature senescence.

  12. Protective Effects of Ferulic Acid against Heat Stress-Induced Intestinal Epithelial Barrier Dysfunction In Vitro and In Vivo.

    Directory of Open Access Journals (Sweden)

    Shasha He

    Full Text Available Heat stress is important in the pathogenesis of intestinal epithelial barrier dysfunction. Ferulic acid (FA, a phenolic acid widely found in fruits and vegetables, can scavenge free radicals and activate cell stress responses. This study is aimed at investigating protective effects of FA on heat stress-induced dysfunction of the intestinal epithelial barrier in vitro and in vivo. Intestinal epithelial (IEC-6 cells were pretreated with FA for 4 h and then exposed to heat stress. Heat stress caused decreased transepithelial electrical resistance (TER and increased permeability to 4-kDa fluorescein isothiocyanate (FITC-dextran (FD4. Both effects were inhibited by FA in a dose-dependent manner. FA significantly attenuated the decrease in occludin, ZO-1 and E-cadherin expression observed with heat stress. The distortion and redistribution of occludin, ZO-1 and E-cadherin proteins were also effectively prevented by FA pretreatment. Moreover, heat stress diminished electron-dense material detected in tight junctions (TJs, an effect also alleviated by FA in a dose-dependent manner. In an in vivo heat stress model, FA (50 mg/kg was administered to male Sprague-Dawley rats for 7 consecutive days prior to exposure to heat stress. FA pretreatment significantly attenuated the effects of heat stress on the small intestine, including the increased FD4 permeability, disrupted tight junctions and microvilli structure, and reduced occludin, ZO-1 and E-cadherin expression. Taken together, our results demonstrate that FA pretreatment is potentially protective against heat stress-induced intestinal epithelial barrier dysfunction.

  13. Oxidative Stress Responses in the Human Fungal Pathogen, Candida albicans

    Directory of Open Access Journals (Sweden)

    Alessandra da Silva Dantas

    2015-02-01

    Full Text Available Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS, such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen.

  14. Occupational stress among radiographers: the impact of sonography responsibility

    Directory of Open Access Journals (Sweden)

    Mr. Nnaoma Franza Oluware

    2009-01-01

    Full Text Available Role extension in any occupation can affect both psychosocial and biomechanical stress levels and thus, have some consequences on efficiency in service delivery. The study was aimed to determine the impact of role extension of medical radiographers into sonography. 50 self-administered questionnaires were distributed to radiographers and to sonographers (radiographers with sonography responsibility. The questionnaires included questions seeking information on the demographic profile of the radiographer and sonographer, anatomical regions of biomechanical symptoms/stress and visual analogue scale (VAS, which rated job satisfaction and anxiety levels. 96% of the questionnaires were returned and analyzed statistically using SPSS 11.0 software with P< 0.05 indicating level of significance. Sonographers had more prevalence of biomechanical stress symptoms than the radiographers. Job satisfaction for sonographers (58.75% was lower than that for radiographers (64.29%. Anxiety level was higher among sonographers even though this was not statistically significant. Sonography responsibility on radiographers did not have any significant effect on psychosocial stress. A balance in the extended role could aid efficiency in service delivery while improving the social strength of the individual.

  15. Osmotic stress response in the wine yeast Dekkera bruxellensis.

    Science.gov (United States)

    Galafassi, Silvia; Toscano, Marco; Vigentini, Ileana; Piškur, Jure; Compagno, Concetta

    2013-12-01

    Dekkera bruxellensis is mainly associated with lambic beer fermentation and wine production and may contribute in a positive or negative manner to the flavor development. This yeast is able to produce phenolic compounds, such as 4-ethylguaiacol and 4-ethylphenol which could spoil the wine, depending on their concentration. In this work we have investigated how this yeast responds when exposed to conditions causing osmotic stress, as high sorbitol or salt concentrations. We observed that osmotic stress determined the production and accumulation of intracellular glycerol, and the expression of NADH-dependent glycerol-3-phosphate dehydrogenase (GPD) activity was elevated. The involvement of the HOG MAPK pathway in response to this stress condition was also investigated. We show that in D. bruxellensis Hog1 protein is activated by phosphorylation under hyperosmotic conditions, highlighting the conserved role of HOG MAP kinase signaling pathway in the osmotic stress response. Gene Accession numbers in GenBank: DbHOG1: JX65361, DbSTL1: JX965362.

  16. Particle shape effects on the stress response of granular packings.

    Science.gov (United States)

    Athanassiadis, Athanasios G; Miskin, Marc Z; Kaplan, Paul; Rodenberg, Nicholas; Lee, Seung Hwan; Merritt, Jason; Brown, Eric; Amend, John; Lipson, Hod; Jaeger, Heinrich M

    2014-01-01

    We present measurements of the stress response of packings formed from a wide range of particle shapes. Besides spheres these include convex shapes such as the Platonic solids, truncated tetrahedra, and triangular bipyramids, as well as more complex, non-convex geometries such as hexapods with various arm lengths, dolos, and tetrahedral frames. All particles were 3D-printed in hard resin. Well-defined initial packing states were established through preconditioning by cyclic loading under given confinement pressure. Starting from such initial states, stress-strain relationships for axial compression were obtained at four different confining pressures for each particle type. While confining pressure has the largest overall effect on the mechanical response, we find that particle shape controls the details of the stress-strain curves and can be used to tune packing stiffness and yielding. By correlating the experimentally measured values for the effective Young's modulus under compression, yield stress and energy loss during cyclic loading, we identify trends among the various shapes that allow for designing a packing's aggregate behavior.

  17. Stress induced hypertensive response: should it be evaluated more carefully?

    Directory of Open Access Journals (Sweden)

    Kucukler Nagehan

    2011-08-01

    Full Text Available Abstract Various diagnostic methods have been used to evaluate hypertensive patients under physical and pharmacological stress. Several studies have shown that exercise hypertension has an independent, adverse impact on outcome; however, other prognostic studies have shown that exercise hypertension is a favorable prognostic indicator and associated with good outcome. Exercise hypertension may be encountered as a warning signal of hypertension at rest and future hypertensive left ventricular hypertrophy. The results of diagnostic stress tests support that hypertensive response to exercise is frequently associated with high rate-pressure product in hypertensives. In addition to the observations on high rate-pressure product and enhanced ventricular contractility in patients with hypertension, evaluation of myocardial contractility by Doppler tissue imaging has shown hyperdynamic myocardial function under pharmacological stress. These recent quantitative data in hypertensives suggest that hyperdynamic myocardial function and high rate-pressure product response to stress may be related to exaggerated hypertension, which may have more importance than that it has been already given in clinical practice.

  18. Peripheral vascular responses to heat stress after hindlimb suspension

    Science.gov (United States)

    Looft-Wilson, Robin C.; Gisolfi, Carl V.

    2002-01-01

    PURPOSE: The purpose of this study was to determine whether hindlimb suspension (which simulates the effects of microgravity) results in impaired hemodynamic responses to heat stress or alterations in mesenteric small artery sympathetic nerve innervation. METHODS: Over 28 d, 16 male Sprague-Dawley rats were hindlimb-suspended, and 13 control rats were housed in the same type of cage. After the treatment, mean arterial pressure (MAP), colonic temperature (Tcol), and superior mesenteric and iliac artery resistances (using Doppler flowmetry) were measured during heat stress [exposure to 42 degrees C until the endpoint of 80 mm Hg blood pressure was reached (75 +/- 9 min); endpoint Tcore = 43.6 +/- 0.2] while rats were anesthetized (sodium pentobarbital, 50 mg x kg(-1) BW). RESULTS: Hindlimb-suspended and control rats exhibited similar increases in Tcol, MAP, and superior mesenteric artery resistance, and similar decreases in iliac resistance during heat stress (endpoint was a fall in MAP below 80 mm Hg). Tyrosine hydroxylase immunostaining indicated similar sympathetic nerve innervation in small mesenteric arteries from both groups. CONCLUSION: Hindlimb suspension does not alter the hemodynamic or thermoregulatory responses to heat stress in the anesthetized rat or mesenteric sympathetic nerve innervation, suggesting that this sympathetic pathway is intact.

  19. Low dose radiation induced adaptive response upon salt stress and vacuum stress: a possible mechanism for the effect of saddle-like dose response curve

    International Nuclear Information System (INIS)

    To explore mechanism for the effect of saddle-like dose-response curve, the relationship of irradiation-vacuum stress, and irradiation-salt stress, was investigated with rice seeds irradiated to 60-560 Gy by 60Co γ-rays. The dose-response curve was simulated based on seedling height data, which showed obedient to linear-quadratic model. During germination,the irradiated rice seeds were stressed by 10-3 Pa vacuum, or by NaCl in different concentrations. After that, the dose-response curve manifested a saddle-like shape. The results indicate that while low dose irradiation could retard seedling growth synergistically with vacuum stress and salt stress, it could also induce adaptive response upon vacuum stress and salt stress. Low dose irradiation induced adaptive response upon environmental adverse factors could contribute to the mechanism for the effect of saddle-like dose-response curve. (authors)

  20. Cold-stress responses in the Antarctic basidiomycetous yeast Mrakia blollopis.

    Science.gov (United States)

    Tsuji, Masaharu

    2016-07-01

    Microbes growing at subzero temperatures encounter numerous growth constraints. However, fungi that inhabit cold environments can grow and decompose organic compounds under subzero temperatures. Thus, understanding the cold-adaptation strategies of fungi under extreme environments is critical for elucidating polar-region ecosystems. Here, I report that two strains of the Antarctic basidiomycetous yeast Mrakia blollopis exhibited distinct growth characteristics under subzero conditions: SK-4 grew efficiently, whereas TKG1-2 did not. I analysed the metabolite responses elicited by cold stress in these two M. blollopis strains by using capillary electrophoresis-time-of-flight mass spectrometry. M. blollopis SK-4, which grew well under subzero temperatures, accumulated high levels of TCA-cycle metabolites, lactic acid, aromatic amino acids and polyamines in response to cold shock. Polyamines are recognized to function in cell-growth and developmental processes, and aromatic amino acids are also known to improve cell growth at low temperatures. By contrast, in TKG1-2, which did not grow efficiently, cold stress strongly induced the metabolites of the TCA cycle, but other metabolites were not highly accumulated in the cell. Thus, these differences in metabolite responses could contribute to the distinct abilities of SK-4 and TKG1-2 cells to grow under subzero temperature conditions. PMID:27493768

  1. Proteomic Study for Responses to Cadmium Stress in Rice Seedlings

    Institute of Scientific and Technical Information of China (English)

    GE Cai-lin; WANG Ze-gang; WAN Ding-zhen; DING Yan; WANG Yu-long; SHANG Qi; LUO Shi-shi

    2009-01-01

    A proteomic approach including two-dimensional electrophoresis and mass spectrometric (MALDI-TOF MS) analyses was used to investigate the responses to cadmium (Cd) stress in seedlings of rice (Oryza sativa L.) varieties Shanyou 63 and Aizaizhan. Cd stress significantly inhibited root and shoot growth, and affected the global proteome in rice roots and leaves, which induced or upregulated the expression of corresponding proteins in rice roots and leaves when rice seedlings were exposed to 0.1 or 1.0 mmol/L Cd. The Cd-induced proteins are involved in chelation and compartmentation of Cd, elimination of active oxygen free radicals, detoxification of toxic substances, degradation of denatured proteins or inactivated enzymes, regulation of physiologic metabolism and induction of pathogenesis-related proteins. Comparing the Cd-induced proteins between the two varieties, the β-glucosidase and pathogenesis-related protein family 10 proteins were more drastically induced by Cd stress in roots and leaves of Aizaizhan, and the UDP-glucose protein transglucosylase and translational elongation factor Tu were induced by 0.1 mmol/L Cd stress in roots of Shanyou 63. This may be one of the important mechanisms for higher tolerance to Cd stress in Shanyou 63 than in Aizaizhan.

  2. Microbial modulation of behavior and stress responses in zebrafish larvae.

    Science.gov (United States)

    Davis, Daniel J; Bryda, Elizabeth C; Gillespie, Catherine H; Ericsson, Aaron C

    2016-09-15

    The influence of the microbiota on behavior and stress responses is poorly understood. Zebrafish larvae have unique characteristics that are advantageous for neuroimmune research, however, they are currently underutilized for such studies. Here, we used germ-free zebrafish to determine the effects of the microbiota on behavior and stress testing. The absence of a microbiota dramatically altered locomotor and anxiety-related behavior. Additionally, characteristic responses to an acute stressor were also obliterated in larvae lacking exposure to microbes. Lastly, treatment with the probiotic Lactobacillus plantarum was sufficient to attenuate anxiety-related behavior in conventionally-raised zebrafish larvae. These results underscore the importance of the microbiota in communicating to the CNS via the microbiome-gut-brain axis and set a foundation for using zebrafish larvae for neuroimmune research. PMID:27217102

  3. Elevated oxidative stress and sensorimotor deficits but normal cognition in mice that cannot synthesize ascorbic acid

    OpenAIRE

    Harrison, Fiona E.; Yu, S Sarah; Van Den Bossche, Kristen L; Li, Liying; May, James M.; McDonald, Michael P.

    2008-01-01

    Oxidative stress is implicated in the cognitive deterioration associated with normal aging as well as neurodegenerative disorders such as Alzheimer’s and Parkinson's diseases. We investigated the effect of ascorbic acid (vitamin C) on oxidative stress, cognition and motor abilities in mice null for gulono-γ-lactone oxidase (Gulo). Gulo−/− mice are unable to synthesize ascorbic acid and depend on dietary ascorbic acid for survival. Gulo−/− mice were given supplements that provided them either ...

  4. Nitrosative and oxidative stress responses in fungal pathogenicity

    OpenAIRE

    Brown, Alistair JP; Haynes, Ken; Quinn, Janet

    2009-01-01

    Fungal pathogenicity has arisen in polyphyletic manner during evolution, yielding fungal pathogens with diverse infection strategies and with differing degrees of evolutionary adaptation to their human host. Not surprisingly, these fungal pathogens display differing degrees of resistance to the reactive oxygen and nitrogen species used by human cells to counteract infection. Furthermore, whilst evolutionarily conserved regulators, such as Hog1, are central to such stress responses in many fun...

  5. Caenorhabditis elegans stress related gene responses to selected pesticides

    OpenAIRE

    Antoniou-Kourounioti, Melissa

    2010-01-01

    Pesticides are used widely and more than 2 million tons are released in the environment annually (data for 2000-2001, Kiely 2004). Details of their toxicity towards non-target organisms, are not complete for many of these pesticides and serious environmental issues have previously arisen as a result (e.g. effects of DDT on reproduction of wild birds). Unfavourable conditions, including the presence of toxicants, can induce the stress response pathways through which an organism attempts t...

  6. Predicting Performance Under Stressful Conditions Using Galvanic Skin Response

    OpenAIRE

    Mundell, Carter; Vielma, Juan Pablo; Zaman, Tauhid

    2016-01-01

    The rapid growth of the availability of wearable biosensors has created the opportunity for using biological signals to measure worker performance. An important question is how to use such signals to not just measure, but actually predict worker performance on a task under stressful and potentially high risk conditions. Here we show that the biological signal known as galvanic skin response (GSR) allows such a prediction. We conduct an experiment where subjects answer arithmetic questions und...

  7. Epigenetic responses to drought stress in rice (Oryza sativa L.)

    OpenAIRE

    Gayacharan; Joel, A. John

    2013-01-01

    Cytosine methylation polymorphism plays a key role in gene regulation, mainly in expression of genes in crop plants. The differential expression of cytosine methylation over drought stress response was analyzed in rice using drought susceptible but agronomically superior lines IR 20 and CO 43, and drought tolerant genotypes PL and PMK 3 and their F1 hybrids. The parents and hybrids were subjected to two moisture regimes viz., one under drought condition and another under control condition. Th...

  8. ABA biosynthesis defective mutants reduce some free amino acids accumulation under drought stress in tomato leaves in comparison with Arabidopsis plants tissues

    Directory of Open Access Journals (Sweden)

    Adnan Ali Al.Asbahi

    2012-05-01

    Full Text Available The ability of plants to tolerate drought conditions is crucial for plant survival and crop production worldwide. The present data confirm previous findings reported existence of a strong relation between abscisic acid (ABA content and amino acid accumulation as response water stress which is one of the most important defense mechanism activated during water stress in many plant species. Therefore, free amino acids were measured to determine any changes in the metabolite pool in relation to ABA content. The ABA defective mutants of Arabidopsis plants were subjected to leaf dehydration for Arabidopsis on Whatman 3 mm filter paper at room temperature while, tomato mutant plants were subjected to drought stresses for tomato plants by withholding water. To understand the signal transduction mechanisms underlying osmotic stress-regulating gene induction and activation of osmoprotectant free amino acid synthesizing genes, we carried out a genetic screen to isolate Arabidopsis mutants defective in ABA biosynthesis under drought stress conditions. The present results revealed an accumulation of specific free amino acid in water stressed tissues in which majority of free amino acids are increased especially those playing an osmoprotectant role such as proline and glycine. Drought stress related Amino acids contents are significantly reduced in the mutants under water stress condition while they are increased significantly in the wild types plants. The exhibited higher accumulation of other amino acids under stressed condition in the mutant plants suggest that, their expressions are regulated in an ABA independent pathways. In addition, free amino acids content changes during water stress condition suggest their contribution in drought toleration as common compatible osmolytes.

  9. Epidermal stem cells response to radiative genotoxic stress

    International Nuclear Information System (INIS)

    Human skin is the first organ exposed to various environmental stresses, which requires the development by skin stem cells of specific mechanisms to protect themselves and to ensure tissue homeostasis. As stem cells are responsible for the maintenance of epidermis during individual lifetime, the preservation of genomic integrity in these cells is essential. My PhD aimed at exploring the mechanisms set up by epidermal stem cells in order to protect themselves from two genotoxic stresses, ionizing radiation (Gamma Rays) and ultraviolet radiation (UVB). To begin my PhD, I have taken part of the demonstration of protective mechanisms used by keratinocyte stem cells after ionizing radiation. It has been shown that these cells are able to rapidly repair most types of radiation-induced DNA damage. Furthermore, we demonstrated that this repair is activated by the fibroblast growth factor 2 (FGF2). In order to know if this protective mechanism is also operating in cutaneous carcinoma stem cells, we investigated the response to gamma Rays of carcinoma stem cells isolated from a human carcinoma cell line. As in normal keratinocyte stem cells, we demonstrated that cancer stem cells could rapidly repair radio-induced DNA damage. Furthermore, fibroblast growth factor 2 also mediates this repair, notably thanks to its nuclear isoforms. The second project of my PhD was to study human epidermal stem cells and progenitors responses to UVB radiation. Once cytometry and irradiation conditions were set up, the toxicity of UVB radiation has been evaluate in the primary cell model. We then characterized UVB photons effects on cell viability, proliferation and repair of DNA damage. This study allowed us to bring out that responses of stem cells and their progeny to UVB are different, notably at the level of part of their repair activity of DNA damage. Moreover, progenitors and stem cells transcriptomic responses after UVB irradiation have been study in order to analyze the global

  10. Stress Response of Offshore Structures by Equivalent Polynomial Expansion Techniques

    DEFF Research Database (Denmark)

    Sigurdsson, Gudfinnur; Nielsen, Søren R.K.

    This paper concerns an investigation of the effects of nonlinearity of drag loading on offshore structures excited by 2D wave fields, where the nonlinear term in the Morison equation is replaced by an equivalent cubic expansion. The equivalent cubic expansion coefficients for the equivalent drag...... model are obtained using the least mean square procedure. Numerical results are given. The displacement response and stress response processes obtained using the above loading model are compared with simulation results and those obtained from equivalent linearization of the drag term....

  11. Longevity and the stress response in Drosophila

    DEFF Research Database (Denmark)

    Vermeulen, Corneel J.; Loeschcke, Volker

    2007-01-01

    substances. Do these same changes in patterns of expression have the ability to mitigate ageing and prolong lifespan? It appears that parts of this response indeed are also associated with extended longevity, whereas some elements are not, due to their high cost or long-term deleterious consequences. Here we...... briefly review the state of the art of research on ageing and longevity in the model organism Drosophila, with focus on the role of the general stress response. We will conclude by contemplating some of the implications of the findings in this research and will suggest several directions for future...

  12. Physical and psychological stress have similar effects on gastric acid and pepsin secretions in rat

    Directory of Open Access Journals (Sweden)

    Ehsan Salimi

    2011-05-01

    Full Text Available Stress is one of the most important health and social problems. Previous studies have demonstrated stress influence on the clinical course of a number of gastrointestinal diseases, but its physical and psychological effects on gastric acid and pepsin secretions are largely unknown. 48 male wistar rats weighing 200-250 gr were used in this study. Animals were divided into 6 groups (n=8; Control, Physical stress, Psychological stress, L-NAME+ Physical stress and L-NAME+ Psychological stress groups. In this study, electrical shock generated in a communication box was used as physical shock and the emotional stress was as psychological stress.Gastric juice was collected by washout technique. Acid output was also measured by digital titrator. Gastric pepsin and nitric oxide (NO metabolites were quantified using Anson and Griess micro assay methods respectively.Basal and stimulated gastric acid and pepsin in physical and psychological stress groups were significantly more than others. NO metabolites level of gastric tissue in physical and psychological stress groups (286.9 ± 5.8, 287.7 ± 5.7 μmol/gr weight wet tissue, respectively were significantly more than other groups. But no significant differences among basal and stimulated gastric acid, pepsin and NO metabolites level were seen in physical and psychological stress groups.

  13. Identification of Novel Stress-responsive Transcription Factor Genes in Rice by cDNA Array Analysis

    Institute of Scientific and Technical Information of China (English)

    Cong-Qing Wu; Hong-Hong Hu; Ya Zeng; Da-Cheng Liang; Ka-Bin Xie; Jian-Wei Zhang; Zhao-Hui Chu; Li-Zhong Xiong

    2006-01-01

    Numerous studies have shown that array of transcription factors has a role in regulating plant responses to environmental stresses. Only a small portion of them however, have been identified or characterized.More than 2 300 putative transcription factors were predicted in the rice genome and more than half of them were supported by expressed sequences. With an attempt to identify novel transcription factors involved in the stress responses, a cDNA array containing 753 putative rice transcription factors was generated to analyze the transcript profiles of these genes under drought and salinity stresses and abscisic acid treatment at seedling stage of rice. About 80% of these transcription factors showed detectable levels of transcript in seedling leaves. A total of 18 up-regulated transcription factors and 29 down-regulated transcription factors were detected with the folds of changes from 2.0 to 20.5 in at least one stress treatment.Most of these stress-responsive genes have not been reported and the expression patterns for five genes under stress conditions were further analyzed by RNA gel blot analysis. These novel stress-responsive transcription factors provide new opportunities to study the regulation of gene expression in plants under stress conditions.

  14. Genome-wide expression analysis offers new insights into the origin and evolution of Physcomitrella patens stress response

    KAUST Repository

    Khraiwesh, Basel

    2015-11-30

    Changes in the environment, such as those caused by climate change, can exert stress on plant growth, diversity and ultimately global food security. Thus, focused efforts to fully understand plant response to stress are urgently needed in order to develop strategies to cope with the effects of climate change. Because Physcomitrella patens holds a key evolutionary position bridging the gap between green algae and higher plants, and because it exhibits a well-developed stress tolerance, it is an excellent model for such exploration. Here, we have used Physcomitrella patens to study genome-wide responses to abiotic stress through transcriptomic analysis by a high-throughput sequencing platform. We report a comprehensive analysis of transcriptome dynamics, defining profiles of elicited gene regulation responses to abiotic stress-associated hormone Abscisic Acid (ABA), cold, drought, and salt treatments. We identified more than 20,000 genes expressed under each aforementioned stress treatments, of which 9,668 display differential expression in response to stress. The comparison of Physcomitrella patens stress regulated genes with unicellular algae, vascular and flowering plants revealed genomic delineation concomitant with the evolutionary movement to land, including a general gene family complexity and loss of genes associated with different functional groups.

  15. Analysis of Small RNAs in Streptococcus mutans under Acid Stress-A New Insight for Caries Research.

    Science.gov (United States)

    Liu, Shanshan; Tao, Ye; Yu, Lixia; Zhuang, Peilin; Zhi, Qinghui; Zhou, Yan; Lin, Huancai

    2016-01-01

    Streptococcus mutans (S. mutans) is the major clinical pathogen responsible for dental caries. Its acid tolerance has been identified as a significant virulence factor for its survival and cariogenicity in acidic conditions. Small RNAs (sRNAs) are recognized as key regulators of virulence and stress adaptation. Here, we constructed three libraries of sRNAs with small size exposed to acidic conditions for the first time, followed by verification using qRT-PCR. The levels of two sRNAs and target genes predicted to be bioinformatically related to acid tolerance were further evaluated under different acid stress conditions (pH 7.5, 6.5, 5.5, and 4.5) at three time points (0.5, 1, and 2 h). Meanwhile, bacterial growth characteristics and vitality were assessed. We obtained 1879 sRNAs with read counts of at least 100. One hundred and ten sRNAs were perfectly mapped to reported msRNAs in S. mutans. Ten out of 18 sRNAs were validated by qRT-PCR. The survival of bacteria declined as the acid was increased from pH 7.5 to 4.5 at each time point. The bacteria can proliferate under each pH except pH 4.5 with time. The levels of sRNAs gradually decreased from pH 7.5 to 5.5, and slightly increased in pH 4.5; however, the expression levels of target mRNAs were up-regulated in acidic conditions than in pH 7.5. These results indicate that some sRNAs are specially induced at acid stress conditions, involving acid adaptation, and provide a new insight into exploring the complex acid tolerance for S. mutans. PMID:27649155

  16. Differential oxidative stress responses in castor semilooper, Achaea janata.

    Science.gov (United States)

    Pavani, Ayinampudi; Chaitanya, R K; Chauhan, Vinod K; Dasgupta, Anwesha; Dutta-Gupta, Aparna

    2015-11-01

    Balance between reactive oxygen species (ROS) and the antioxidant (AO) defense mechanisms is vital for organism survival. Insects serve as an ideal model to elucidate oxidative stress responses as they are prone to different kinds of stress during their life cycle. The present study demonstrates the modulation of AO enzyme gene expression in the insect pest, Achaea janata (castor semilooper), when subjected to different oxidative stress stimuli. Antioxidant enzymes' (catalase (Cat), superoxide dismutase (Sod), glutathione-S-transferase (GST) and glutathione peroxidase (Gpx)) partial coding sequences were cloned and characterized from larval whole body. Tissue expression studies reveal a unique pattern of AO genes in the larval tissues with maximum expression in the gut and fat body. Ontogeny profile depicts differential expression pattern through the larval developmental stages for each AO gene studied. Using quantitative RT-PCR, the expression pattern of these genes was monitored during sugar-induced (d-galactose feeding), infection-induced (Gram positive, Gram negative and non-pathogenic bacteria) and pesticide-induced oxidative stress (Bt Cry toxin). d-Galactose feeding differentially modulates the expression of AO genes in the larval gut and fat body. Immune challenge with Escherichia coli induces robust upregulation of AO genes when compared to Bacillus coagulans and Bacillus cereus in the larval fat body and gut. Cry toxin feeding predominantly induced GST upregulation in the gut. The current study suggests that though there are multiple ways of generation of oxidative stress in the insect, the organism tailors its response by insult- and tissue-specific recruitment of the antioxidant players and their differential regulation for each inducer.

  17. Differential oxidative stress responses in castor semilooper, Achaea janata.

    Science.gov (United States)

    Pavani, Ayinampudi; Chaitanya, R K; Chauhan, Vinod K; Dasgupta, Anwesha; Dutta-Gupta, Aparna

    2015-11-01

    Balance between reactive oxygen species (ROS) and the antioxidant (AO) defense mechanisms is vital for organism survival. Insects serve as an ideal model to elucidate oxidative stress responses as they are prone to different kinds of stress during their life cycle. The present study demonstrates the modulation of AO enzyme gene expression in the insect pest, Achaea janata (castor semilooper), when subjected to different oxidative stress stimuli. Antioxidant enzymes' (catalase (Cat), superoxide dismutase (Sod), glutathione-S-transferase (GST) and glutathione peroxidase (Gpx)) partial coding sequences were cloned and characterized from larval whole body. Tissue expression studies reveal a unique pattern of AO genes in the larval tissues with maximum expression in the gut and fat body. Ontogeny profile depicts differential expression pattern through the larval developmental stages for each AO gene studied. Using quantitative RT-PCR, the expression pattern of these genes was monitored during sugar-induced (d-galactose feeding), infection-induced (Gram positive, Gram negative and non-pathogenic bacteria) and pesticide-induced oxidative stress (Bt Cry toxin). d-Galactose feeding differentially modulates the expression of AO genes in the larval gut and fat body. Immune challenge with Escherichia coli induces robust upregulation of AO genes when compared to Bacillus coagulans and Bacillus cereus in the larval fat body and gut. Cry toxin feeding predominantly induced GST upregulation in the gut. The current study suggests that though there are multiple ways of generation of oxidative stress in the insect, the organism tailors its response by insult- and tissue-specific recruitment of the antioxidant players and their differential regulation for each inducer. PMID:26455997

  18. Neutralization of Tumor Acidity Improves Antitumor Responses to Immunotherapy.

    Science.gov (United States)

    Pilon-Thomas, Shari; Kodumudi, Krithika N; El-Kenawi, Asmaa E; Russell, Shonagh; Weber, Amy M; Luddy, Kimberly; Damaghi, Mehdi; Wojtkowiak, Jonathan W; Mulé, James J; Ibrahim-Hashim, Arig; Gillies, Robert J

    2016-03-15

    Cancer immunotherapies, such as immune checkpoint blockade or adoptive T-cell transfer, can lead to durable responses in the clinic, but response rates remain low due to undefined suppression mechanisms. Solid tumors are characterized by a highly acidic microenvironment that might blunt the effectiveness of antitumor immunity. In this study, we directly investigated the effects of tumor acidity on the efficacy of immunotherapy. An acidic pH environment blocked T-cell activation and limited glycolysis in vitro. IFNγ release blocked by acidic pH did not occur at the level of steady-state mRNA, implying that the effect of acidity was posttranslational. Acidification did not affect cytoplasmic pH, suggesting that signals transduced by external acidity were likely mediated by specific acid-sensing receptors, four of which are expressed by T cells. Notably, neutralizing tumor acidity with bicarbonate monotherapy impaired the growth of some cancer types in mice where it was associated with increased T-cell infiltration. Furthermore, combining bicarbonate therapy with anti-CTLA-4, anti-PD1, or adoptive T-cell transfer improved antitumor responses in multiple models, including cures in some subjects. Overall, our findings show how raising intratumoral pH through oral buffers therapy can improve responses to immunotherapy, with the potential for immediate clinical translation. PMID:26719539

  19. Decreased response to social defeat stress in μ-opioid-receptor knockout mice

    OpenAIRE

    Komatsu, Hiroshi; Ohara, Arihisa; Sasaki, Kazumasu; Abe, Hiromi; Hattori, Hisaki; Hall, F Scott; Uhl, George R.; Sora, Ichiro

    2011-01-01

    Substantial evidence exists that opioid systems are involved in stress response and that changes in opioid systems in response to stressors affect both reward and analgesia. Reportedly, mice suffering chronic social defeat stress subsequently show aversion to social contact with unfamiliar mice. To further examine the role of opioid systems in stress response, the behavioral and neurochemical effects of chronic social defeat stress (psychosocial stress) were evaluated in μ-opioid-receptor kno...

  20. A robust and reliable non-invasive test for stress responsivity in mice

    OpenAIRE

    Zimprich, Annemarie; Garrett, Lillian; Deussing, Jan M.; Carsten T. Wotjak; Fuchs, Helmut; Gailus-Durner, Valerie; de Angelis, Martin Hrabě; Wurst, Wolfgang; Hölter, Sabine M.

    2014-01-01

    Stress and an altered stress response have been associated with many multifactorial diseases, such as psychiatric disorders or neurodegenerative diseases. As currently mouse mutants for each single gene are generated and phenotyped in a large-scale manner, it seems advisable also to test these mutants for alterations in their stress responses. Here we present the determinants of a robust and reliable non-invasive test for stress-responsivity in mice. Stress is applied through restraining the ...

  1. Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli.

    Energy Technology Data Exchange (ETDEWEB)

    Lennen, Rebecca M.; Kruziki, Max A.; Kumar, Kritika; Zinkel, Robert A.; Burnum, Kristin E.; Lipton, Mary S.; Hoover, Spencer W.; Ranatunga, Don Ruwan; Wittkopp, Tyler M.; Marner II, Wesley D.; Pfleger, Brian F.

    2011-11-01

    Microbially produced fatty acids are potential precursors to high energy density biofuels, including alkanes and alkyl ethyl esters by either catalytic conversion of free fatty acids (FFAs) or enzymatic conversions of acyl-acyl carrier protein or acyl-coenzyme A intermediates. Metabolic engineering efforts aimed at overproducing FFAs in Escherichia coli have achieved less than 30% of the maximum theoretical yield on the supplied carbon source. In this work, the viability, morphology, transcript levels, and protein levels of a strain of E. coli that overproduces medium chain length FFAs was compared to an engineered control strain. By early stationary phase, an 85% reduction in viable cell counts and exacerbated loss of inner membrane integrity were observed in the FFA overproducing strain. These effects were enhanced in strains endogenously producing FFAs compared to strains exposed to exogenously fed FFAs. Under two sets of cultivation conditions, long chain unsaturated fatty acid content greatly increased and the expression of genes and proteins required for unsaturated fatty acid biosynthesis were significantly decreased. Membrane stresses were further implicated by increased expression of genes and proteins of the phage shock response, the MarA/Rob/SoxS regulon, and the nuo and cyo operons of aerobic respiration. Gene deletion studies confirmed the importance of the phage shock proteins and Rob for maintaining cell viability, however little to no change in FFA titers was observed after 24 h cultivation. The results of this study serve as a baseline for future targeted attempts to improve FFA yields and titers in E. coli.

  2. Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

    Directory of Open Access Journals (Sweden)

    Su Zhen

    2011-07-01

    Full Text Available Abstract Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants.

  3. The role of cyclooxygenase-2/prostanoid pathway in visceral pain induced liver stress response in rats

    Institute of Scientific and Technical Information of China (English)

    PISTON Donald; WANG Shan; FENG Yi; YE Ying-jiang; ZHOU Jing; JIANG Ke-wei; XU Feng; ZHAO Yong; CUI Zhi-rong

    2007-01-01

    Background Cyclooxygenase (COX) is the rate-limiting enzyme in the production of prostanoids from arachidonic acid.COX-2 is the inducible enzyme in the COX family, together with the prostanoids forms the COX-2/prostanoid pathway.Research showed that the COX-2/prostanoid pathway is activated in hepatic diseases and liver stress reaction, such as fibrogenesis, portal hypertension, carcinogenesis, and ischemic/reperfusion injury. But there was no report on visceral pain induced liver stress. This study was to investigate the role of the COX-2/prostanoid pathway in liver stress response in rat acute colitis visceral pain liver stress model.Methods Fifty-three male SD rats were randomly divided into Naive, Model, NS398 treatment, and Morphine treatment groups. The rat acute colitis visceral pain liver stress model was established under anesthesia by the colonic administration of 0.5 ml of 6% acetic acid using a urethral catheter. NS398 and morphine were administrated 30 minutes prior to model establishment in NS398 and Morphine treatment groups respectively. Spontaneous activities and pain behavior were counted and the extent of colonic inflammation was assessed histologically. Liver tissue levels of Glutathione-S-Transferase (GST) activity, COX-2 mRNA, prostaglandin E2 (PGE2), thromboxane B2 (TXB2) and 6-Ketone-prostaglandin F1α (6-K-PGF1α) contents were assessed.Results Thirty minutes after the colonic administration of acetic acid, a significant decrease in spontaneous activities and an increase in pain behaviors were observed in Model group (P<0.01 and P<0.05 respectively), accompanied by colonic inflammation. Liver GST activity levels significantly dropped (P<0.05). Liver COX-2 mRNA expression significantly increased, accompanied by an increase in liver concentrations of PGE2 and TXB2, but no obvious change in 6-K-PGF1α concentrations. NS398 and morphine both ameliorated post-stress liver GST activity (P<0.05 and P<0.01respectively), decreased stress

  4. Severe Injury Is Associated With Insulin Resistance, Endoplasmic Reticulum Stress Response, and Unfolded Protein Response

    Science.gov (United States)

    Jeschke, Marc G.; Finnerty, Celeste C.; Herndon, David N.; Song, Juquan; Boehning, Darren; Tompkins, Ronald G.; Baker, Henry V.; Gauglitz, Gerd G.

    2012-01-01

    Objective We determined whether postburn hyperglycemia and insulin resistance are associated with endoplasmic reticulum (ER) stress/unfolded protein response (UPR) activation leading to impaired insulin receptor signaling. Background Inflammation and cellular stress, hallmarks of severely burned and critically ill patients, have been causally linked to insulin resistance in type 2 diabetes via induction of ER stress and the UPR. Methods Twenty severely burned pediatric patients were compared with 36 nonburned children. Clinical markers, protein, and GeneChip analysis were used to identify transcriptional changes in ER stress and UPR and insulin resistance–related signaling cascades in peripheral blood leukocytes, fat, and muscle at admission and up to 466 days postburn. Results Burn-induced inflammatory and stress responses are accompanied by profound insulin resistance and hyperglycemia. Genomic and protein analysis revealed that burn injury was associated with alterations in the signaling pathways that affect insulin resistance, ER/sarcoplasmic reticulum stress, inflammation, and cell growth/apoptosis up to 466 days postburn. Conclusion Burn-induced insulin resistance is associated with persistent ER/sarcoplasmic reticulum stress/UPR and subsequent suppressed insulin receptor signaling over a prolonged period of time. PMID:22241293

  5. Transcriptome-wide survey and expression analysis of stress-responsive NAC genes in Chrysanthemum lavandulifolium.

    Science.gov (United States)

    Huang, He; Wang, Yi; Wang, Shunli; Wu, Xuan; Yang, Ke; Niu, Yajing; Dai, Silan

    2012-09-01

    The plant-specific NAC (NAM, ATAF, and CUC) transcription factor family plays a vital role in various plant growth and developmental processes as well as in stress resistance. Using RNA sequencing, we found that the ClNAC genes (ClNAC1-44) were the most strongly up-regulated transcription factor family in Chrysanthemum lavandulifolium leaves under salt treatment. We carried out reverse transcriptase polymerase chain reaction to monitor ClNAC genes response against multiple stresses and hormonal treatments including salt, drought, cold, heat, abscisic acid and salicylic acid treatments. The results showed that 35 ClNAC genes were differentially expressed in different organ, and 32 ClNAC genes could respond to at least 2 kinds of treatments. Quantitative real time polymerase chain reaction showed that 10 ClNAC genes belonging to 7 different subfamilies could respond to at least 5 kinds of treatments. Over 50-fold variation in transcriptional levels of ClNAC17 and ClNAC21 genes was observed under 6 different types of treatments. In the present study, high-level expression of ClNAC genes under abiotic stresses and hormonal treatments suggests that the NAC transcription factors play important roles in abiotic stress tolerance and adaptation.

  6. Reconstructing a Network of Stress-Response Regulators via Dynamic System Modeling of Gene Regulation

    Directory of Open Access Journals (Sweden)

    Wei-Sheng Wu

    2008-01-01

    Full Text Available Unicellular organisms such as yeasts have evolved mechanisms to respond to environmental stresses by rapidly reorganizing the gene expression program. Although many stress-response genes in yeast have been discovered by DNA microarrays, the stress-response transcription factors (TFs that regulate these stress-response genes remain to be investigated. In this study, we use a dynamic system model of gene regulation to describe the mechanism of how TFs may control a gene’s expression. Then, based on the dynamic system model, we develop the Stress Regulator Identification Algorithm (SRIA to identify stress-response TFs for six kinds of stresses. We identified some general stress-response TFs that respond to various stresses and some specific stress-response TFs that respond to one specifi c stress. The biological significance of our findings is validated by the literature. We found that a small number of TFs is probably suffi cient to control a wide variety of expression patterns in yeast under different stresses. Two implications can be inferred from this observation. First, the response mechanisms to different stresses may have a bow-tie structure. Second, there may be regulatory cross-talks among different stress responses. In conclusion, this study proposes a network of stress-response regulators and the details of their actions.

  7. Reconstructing a network of stress-response regulators via dynamic system modeling of gene regulation.

    Science.gov (United States)

    Wu, Wei-Sheng; Li, Wen-Hsiung; Chen, Bor-Sen

    2008-02-10

    Unicellular organisms such as yeasts have evolved mechanisms to respond to environmental stresses by rapidly reorganizing the gene expression program. Although many stress-response genes in yeast have been discovered by DNA microarrays, the stress-response transcription factors (TFs) that regulate these stress-response genes remain to be investigated. In this study, we use a dynamic system model of gene regulation to describe the mechanism of how TFs may control a gene's expression. Then, based on the dynamic system model, we develop the Stress Regulator Identification Algorithm (SRIA) to identify stress-response TFs for six kinds of stresses. We identified some general stress-response TFs that respond to various stresses and some specific stress-response TFs that respond to one specific stress. The biological significance of our findings is validated by the literature. We found that a small number of TFs is probably sufficient to control a wide variety of expression patterns in yeast under different stresses. Two implications can be inferred from this observation. First, the response mechanisms to different stresses may have a bow-tie structure. Second, there may be regulatory cross-talks among different stress responses. In conclusion, this study proposes a network of stress-response regulators and the details of their actions.

  8. System-level understanding of the potential acid-tolerance components of Acidithiobacillus thiooxidans ZJJN-3 under extreme acid stress.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    In previous study, two extremely acidophilic strains Acidithiobacillus thiooxidans ZJJN-3 (collection site: bioleaching leachate) and ZJJN-5 (collection site: bioleaching wastewater) were isolated from a typical industrial bio-heap in China. Here, we unraveled the potential acid-tolerance components of ZJJN-3 by comparing the physiological differences with ZJJN-5 under different acid stresses. The parameters used for comparison included intracellular pH (pHin), capsule morphology, fatty acid composition of cell membrane, transcription of key molecular chaperones, H(+)-ATPase activities and NAD(+)/NADH ratio. It was indicated that the acid-tolerance of A. thiooxidans ZJJN-3 was systematically regulated. Capsule first thickened and then shed off along with increased acid stress. Cell membrane maintained the intracellular stability by up-regulating the proportion of unsaturated fatty acid and cyclopropane fatty acids. Meanwhile, the transcription of key repair molecular chaperones (GrpE-DnaK-DnaJ) was up-regulated by 2.2-3.5 folds for ensuring the proper folding of peptide. Moreover, low pHin promoted ZJJN-3 to biosynthesize more H(+)-ATPase for pumping H(+) out of cells. Furthermore, the NAD(+)/NADH ratio increased due to the decreased H(+) concentration. Based on the above physiological analysis, the potential acid-tolerance components of A. thiooxidans ZJJN-3 were first proposed and it would be useful for better understanding how these extremophiles responded to the high acid stress.

  9. System-level understanding of the potential acid-tolerance components of Acidithiobacillus thiooxidans ZJJN-3 under extreme acid stress.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    In previous study, two extremely acidophilic strains Acidithiobacillus thiooxidans ZJJN-3 (collection site: bioleaching leachate) and ZJJN-5 (collection site: bioleaching wastewater) were isolated from a typical industrial bio-heap in China. Here, we unraveled the potential acid-tolerance components of ZJJN-3 by comparing the physiological differences with ZJJN-5 under different acid stresses. The parameters used for comparison included intracellular pH (pHin), capsule morphology, fatty acid composition of cell membrane, transcription of key molecular chaperones, H(+)-ATPase activities and NAD(+)/NADH ratio. It was indicated that the acid-tolerance of A. thiooxidans ZJJN-3 was systematically regulated. Capsule first thickened and then shed off along with increased acid stress. Cell membrane maintained the intracellular stability by up-regulating the proportion of unsaturated fatty acid and cyclopropane fatty acids. Meanwhile, the transcription of key repair molecular chaperones (GrpE-DnaK-DnaJ) was up-regulated by 2.2-3.5 folds for ensuring the proper folding of peptide. Moreover, low pHin promoted ZJJN-3 to biosynthesize more H(+)-ATPase for pumping H(+) out of cells. Furthermore, the NAD(+)/NADH ratio increased due to the decreased H(+) concentration. Based on the above physiological analysis, the potential acid-tolerance components of A. thiooxidans ZJJN-3 were first proposed and it would be useful for better understanding how these extremophiles responded to the high acid stress. PMID:26264736

  10. Oxidative stress response induced by atrazine in Palaemonetes argentinus: the protective effect of vitamin E.

    Science.gov (United States)

    Griboff, Julieta; Morales, David; Bertrand, Lidwina; Bonansea, Rocío Inés; Monferrán, Magdalena Victoria; Asis, Ramón; Wunderlin, Daniel Alberto; Amé, María Valeria

    2014-10-01

    The widespread contamination and persistence of the herbicide atrazine residues in the environment resulted in the exposure of non-target organisms. The present study was undertaken to investigate the effect of atrazine in the response of oxidative stress biomarkers in the freshwater shrimp Palaemonetes argentinus and the protective effect of vitamin-E against atrazine-induced toxicity. Therefore, two batches of P. argentinus were fed for 21 days with a commercial food enriched in proteins (D1) or with D2, composed of D1 enriched with vitamin-E (6.8 and 16.0mg% of vitamin-E, respectively). Subsequently, half of the individuals of each group were exposed to atrazine (0.4mgL(-1)) for 24h and the others remained as controls. Atrazine promoted oxidative stress response in P. argentinus fed with D1 as indicated by enhanced H2O2 content and induction of superoxide dismutase, glutathione-S-transferases and glutathione reductase. This antioxidant activity would prevent the increment of thiobarbituric acid reactive substances in the shrimp tissues. P. argentinus fed with D2 reversed the response of the biomarkers measured. However, the activation of antioxidants response had an energetic cost, which was revealed by a decrease in lipids storage in shrimps. These results show the modulatory effect of vit-E on oxidative stress and its potential use as an effective antioxidant to be applied in chemoprotection strategies during aquaculture.

  11. Proteome analysis of alfalfa roots in response to water deifcit stress

    Institute of Scientific and Technical Information of China (English)

    Rahman Md Atikur; Kim Yong-Goo; AlamIftekhar; LIU Gong-she; Lee Hyoshin; Lee Jeung Joo; Lee Byung-Hyun

    2016-01-01

    To evaluate the response of alfalfa to water deifcit (WD) stress, WD-induced candidates were investigated through a proteomic approach. Alfalfa seedlings were exposed to WD stress for 12 and 15 days respectively, folowed by 3 days re-watering. Water deifcit increased H2O2content, lipid peroxidation, DPPH (1,1-diphenyl-2-picrylhydrazyl)-radical scavenging activity, and the free proline level in alfalfa roots. Root proteins were extracted and separated by two-dimentional polyacrylamide gel electrophoresis (2-DE). A total of 49 WD-responsive proteins were identiifed in alfalfa roots; 25 proteins were reproducibly found to be up-regulated and 24 were down-regulated. Two proteins, namely cytosolic ascorbate peroxidase (APx2) and putative F-box protein were newly detected on 2-DE maps of WD-treated plants. We identiifed several proteins including agamous-like 65, albumin b-32, inward rectifying potassium channel, and auxin-independent growth promoter. The identiifed proteins are involved in a variety of celular functions including calcium signaling, abacisic acid (ABA) biosynthesis, reactive oxygen species (ROS) regulation, transcription/ translation, antioxidant/detoxiifcation/stress defense, energy metabolism, signal transduction, and storage. These results indicate the potential candidates were responsible for adaptive response in alfalfa roots.

  12. Hormonal response of the premature primate to operative stress.

    Science.gov (United States)

    Taylor, A F; Lally, K P; Chwals, W J; McCurnin, D C; Gerstmann, D R; Shade, R A; deLemos, R A

    1993-06-01

    There are few data on the hormonal response to operation in the premature infant. Studies examining the response of newborn human infants have been performed on patients beyond the first few days of life, where some adaptation to postnatal life has occurred. This study evaluated the response of the newly born premature primate to surgical stress. Premature baboons (75% gestation) were intubated, mechanically ventilated and underwent thoracotomy at 2 hours of life with exposure of the ductus arteriosus (PDA). In group 1, formalin was infiltrated to keep the ductus patent. In group 2, the PDA was ligated. Controls had no operation. Blood was drawn at 0, 6, 24, 48, 72, and 96 hours of age. Echocardiograms were performed to confirm patency or closure of the ductus and to monitor cardiac function. Epinephrine, norepinephrine, renin, and cortisol levels were measured. Cortisol levels rose in all groups. Operation stimulated a marked increase in catecholamine and renin levels in both operative groups, which was more marked in the group with PDA ligation at 24 hours. These data reflect expected pathophysiology since early PDA ligation exerts additional hemodynamic demand on the heart. In conclusion, the premature primate is able to mount a significant and severity-dependent endocrine response to stress. PMID:8331518

  13. "Stress entropic load" as a transgenerational epigenetic response trigger.

    Science.gov (United States)

    Bienertová-Vašků, Julie; Nečesánek, Ivo; Novák, Jan; Vinklárek, Jan; Zlámal, Filip

    2014-03-01

    Epigenetic changes are generally based on the switching of alternative functional or structural states and result in the adaptation of cellular expression patterns during proliferation, differentiation or plastic changes in the adult organism, whereas some epigenetic information can be passed on other generations while other is not. Hence, the principal question is: why is some information reset or resolved during the meiosis process and other is passed from one generation to another, or, in other words: what "adaptation trigger" level initiates transgenerationally transmitted epigenome change? Hereto, we propose a theory which states that stress, or, more specifically, the energy cost of an individual's adaptation to stress, represents a viable candidate for the transgenerational transmission trigger of a given acquired trait. It has been reported recently that the higher lifetime entropy generation of a unit's body mass, the higher the entropy stress level (which is a measure of energy released by a unit's organ mass) and the irreversibility within the organ, resulting in faster organ degradation and consequent health problems for the entire biological system. We therefore suggest a new term: "stress entropic load" will reflect the actual energetic cost of an individual's adaptation and may be used to estimate the probability of inducing transgenerational response once characterized or measured.

  14. Transcriptome response mediated by cold stress in Lotus japonicus

    Directory of Open Access Journals (Sweden)

    Pablo Ignacio Calzadilla

    2016-03-01

    Full Text Available Members of the Lotus genus are important as agricultural forage sources under marginal environmental conditions given their high nutritional value and tolerance of various abiotic stresses. However, their dry matter production is drastically reduced in cooler seasons, while their response to such conditions is not well studied. This paper analyzes cold acclimation of the genus by studying Lotus japonicus over a stress period of 24 h. High-throughput RNA sequencing was used to identify and classify 1077 differentially expressed genes, of which 713 were up-regulated and 364 were down-regulated. Up-regulated genes were principally related to lipid, cell wall, phenylpropanoid, sugar, and proline regulation, while down-regulated genes affected the photosynthetic process and chloroplast development. Together, a total of 41 cold-inducible transcription factors were identified, including members of the AP2/ERF, NAC, MYB, and WRKY families; two of them were described as putative novel transcription factors. Finally, DREB1/CBFs were described with respect to their cold stress expression profiles. This is the first transcriptome profiling of the model legume L. japonicus under cold stress. Data obtained may be useful in identifying candidate genes for breeding modified species of forage legumes that more readily acclimate to low temperatures

  15. Stress response system and personality in rheumatoid arthritis patients

    Directory of Open Access Journals (Sweden)

    M. Marcenaro

    2011-09-01

    Full Text Available Various factors such as immunogenetic determinants, sex, age and stress paly an important role in the pathogenesis of rheumatoid arthritis (RA. The relationship between stress and RA is still unclear and undefined; however, various lines of research are developing in order to evaluate environmental, psychologic, and biologic stressors as predisposing factors. The aim of our study was to evaluate whether stress-related psychologic factors and personality disorders might be involved in the development of RA, by using a psychometric investigation-methodology in a series of patients. Twenty-three patients underwent a clinical inteview and other specific psychometric tests. Macro and microstressful life-events preceded RA in 83% of the cases. Sixty percent of the patients showed a correlation between flare-ups of the disease and appearance of microevents. An obsessive-compulsive personality was found in 26% of the patients. Anxia was detected in 40% of the patients. Among the group of patients with borderline disorder’s was also detected alexithymia. The high prevalence of major life-events preceding the onset of RA and the presence of personality disorders support the role of the altered stress response system as an importunat pathogenetic factor in the disease.

  16. Systems biology meets stress ecology: linking molecular and organismal stress responses in Daphnia magna

    OpenAIRE

    Heckmann, L. H.; Sibly, R.M; Connon, R.; Hooper, H. L.; Hutchinson, T H; Maund, S.J.; Hill, C. J.; Bouetard, A.; Callaghan, A

    2008-01-01

    Background: Ibuprofen and other nonsteroidal anti-inflammatory drugs have been designed to interrupt eicosanoid metabolism in mammals, but little is known of how they affect nontarget organisms. Here we report a systems biology study that simultaneously describes the transcriptomic and phenotypic stress responses of the model crustacean Daphnia magna after exposure to ibuprofen. Results: Our findings reveal intriguing similarities in the mode of action of ibuprofen between vertebrates and inv...

  17. Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism

    NARCIS (Netherlands)

    Kissoudis, Christos; Sri Sunarti, Sri; De Wiel, Van Clemens; Visser, Richard G.F.; Linden, van der Gerard; Bai, Yuling

    2016-01-01

    Stress conditions in agricultural ecosystems can occur at variable intensities. Different resistance mechanisms against abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effec

  18. Supplementary data: Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and mechanism of resistance

    NARCIS (Netherlands)

    Kissoudis, C.; Sri Sunarti, Sri; Wiel, van de C.C.M.; Visser, R.G.F.; Linden, van der C.G.; Bai, Y.

    2016-01-01

    Stress conditions in agricultural ecosystems can occur in variable intensities. Different resistance mechanisms to abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of

  19. Mitochondrial Composition,Function and Stress Response in Plants

    Institute of Scientific and Technical Information of China (English)

    Richard P.Jacoby; Lei Li; Shaobai Huang; Chun Pong Lee; A.Harvey Millar; Nicolas L.Taylor

    2012-01-01

    The primary function of mitochondria is respiration,where catabolism of substrates is coupled to ATP synthesis via oxidative phosphorylation.In plants,mitochondrial composition is relatively complex and flexible and has specific pathways to support photosynthetic processes in illuminated leaves.This review begins with outlining current models of mitochondrial composition in plant cells,with an emphasis upon the assembly of the complexes of the classical electron transport chain (ETC).Next,we focus upon the comparative analysis of mitochondrial function from different tissue types.A prominent theme in the plant mitochondrial literature involves linking mitochondrial composition to environmental stress responses,and this review then gives a detailed outline of how oxidative stress impacts upon the plant mitochondrial proteome with particular attention to the role of transition metals.This is followed by an analysis of the signaling capacity of mitochondrial reactive oxygen species,which studies the transcriptional changes of stress responsive genes as a framework to define specific signals emanating from the mitochondrion.Finally,specific mitochondrial roles during exposure to harsh environments are outlined,with attention paid to mitochondrial delivery of energy and intermediates,mitochondrial support for photosynthesis,and mitochondrial processes operating within root cells that mediate tolerance to anoxia and unfavorable soil chemistries.

  20. Multifaceted roles of aquaporins as molecular conduits in plant responses to abiotic stresses.

    Science.gov (United States)

    Srivastava, Ashish Kumar; Penna, Suprasanna; Nguyen, Dong Van; Tran, Lam-Son Phan

    2016-06-01

    Abiotic stress has become a challenge to food security due to occurrences of climate change and environmental degradation. Plants initiate molecular, cellular and physiological changes to respond and adapt to various types of abiotic stress. Understanding of plant response mechanisms will aid in strategies aimed at improving stress tolerance in crop plants. One of the most common and early symptoms associated with these stresses is the disturbance in plant-water homeostasis, which is regulated by a group of proteins called "aquaporins". Aquaporins constitute a small family of proteins which are classified further on the basis of their localization, such as plasma membrane intrinsic proteins, tonoplast intrinsic proteins, nodulin26-like intrinsic proteins (initially identified in symbiosomes of legumes but also found in the plasma membrane and endoplasmic reticulum), small basic intrinsic proteins localized in ER (endoplasmic reticulum) and X intrinsic proteins present in plasma membrane. Apart from water, aquaporins are also known to transport CO2, H2O2, urea, ammonia, silicic acid, arsenite and wide range of small uncharged solutes. Besides, aquaporins also function to modulate abiotic stress-induced signaling. Such kind of versatile functions has made aquaporins a suitable candidate for development of transgenic plants with increased tolerance toward different abiotic stress. Toward this endeavor, the present review describes the versatile functions of aquaporins in water uptake, nutrient balancing, long-distance signal transfer, nutrient/heavy metal acquisition and seed development. Various functional genomic studies showing the potential of specific aquaporin isoforms for enhancing plant abiotic stress tolerance are summarized and future research directions are given to design stress-tolerant crops. PMID:25430890

  1. Mcm2 phosphorylation and the response to replicative stress

    Directory of Open Access Journals (Sweden)

    Stead Brent E

    2012-05-01

    Full Text Available Abstract Background The replicative helicase in eukaryotic cells is comprised of minichromosome maintenance (Mcm proteins 2 through 7 (Mcm2-7 and is a key target for regulation of cell proliferation. In addition, it is regulated in response to replicative stress. One of the protein kinases that targets Mcm2-7 is the Dbf4-dependent kinase Cdc7 (DDK. In a previous study, we showed that alanine mutations of the DDK phosphorylation sites at S164 and S170 in Saccharomyces cerevisiae Mcm2 result in sensitivity to caffeine and methyl methanesulfonate (MMS leading us to suggest that DDK phosphorylation of Mcm2 is required in response to replicative stress. Results We show here that a strain with the mcm2 allele lacking DDK phosphorylation sites (mcm2AA is also sensitive to the ribonucleotide reductase inhibitor, hydroxyurea (HU and to the base analogue 5-fluorouracil (5-FU but not the radiomimetic drug, phleomycin. We screened the budding yeast non-essential deletion collection for synthetic lethal interactions with mcm2AA and isolated deletions that include genes involved in the control of genome integrity and oxidative stress. In addition, the spontaneous mutation rate, as measured by mutations in CAN1, was increased in the mcm2AA strain compared to wild type, whereas with a phosphomimetic allele (mcm2EE the mutation rate was decreased. These results led to the idea that the mcm2AA strain is unable to respond properly to DNA damage. We examined this by screening the deletion collection for suppressors of the caffeine sensitivity of mcm2AA. Deletions that decrease spontaneous DNA damage, increase homologous recombination or slow replication forks were isolated. Many of the suppressors of caffeine sensitivity suppressed other phenotypes of mcm2AA including sensitivity to genotoxic drugs, the increased frequency of cells with RPA foci and the increased mutation rate. Conclusions Together these observations point to a role for DDK-mediated phosphorylation

  2. Plant natriuretic peptides are apoplastic and paracrine stress response molecules

    KAUST Repository

    Wang, Yuhua

    2011-04-07

    Higher plants contain biologically active proteins that are recognized by antibodies against human atrial natriuretic peptide (ANP). We identified and isolated two Arabidopsis thaliana immunoreactive plant natriuretic peptide (PNP)-encoding genes, AtPNP-A and AtPNP-B, which are distantly related members of the expansin superfamily and have a role in the regulation of homeostasis in abiotic and biotic stresses, and have shown that AtPNP-A modulates the effects of ABA on stomata. Arabidopsis PNP (PNP-A) is mainly expressed in leaf mesophyll cells, and in protoplast assays we demonstrate that it is secreted using AtPNP-A:green fluorescent protein (GFP) reporter constructs and flow cytometry. Transient reporter assays provide evidence that AtPNP-A expression is enhanced by heat, osmotica and salt, and that AtPNP-A itself can enhance its own expression, thereby generating a response signature diagnostic for paracrine action and potentially also autocrine effects. Expression of native AtPNP-A is enhanced by osmotica and transiently by salt. Although AtPNP-A expression is induced by salt and osmotica, ABA does not significantly modulate AtPNP-A levels nor does recombinant AtPNP-A affect reporter expression of the ABA-responsive RD29A gene. Together, these results provide experimental evidence that AtPNP-A is stress responsive, secreted into the apoplastic space and can enhance its own expression. Furthermore, our findings support the idea that AtPNP-A, together with ABA, is an important component in complex plant stress responses and that, much like in animals, peptide signaling molecules can create diverse and modular signals essential for growth, development and defense under rapidly changing environmental conditions. © 2011 The Author.

  3. Pachymic acid inhibits growth and induces apoptosis of pancreatic cancer in vitro and in vivo by targeting ER stress.

    Science.gov (United States)

    Cheng, Shujie; Swanson, Kristen; Eliaz, Isaac; McClintick, Jeanette N; Sandusky, George E; Sliva, Daniel

    2015-01-01

    Pachymic acid (PA) is a purified triterpene extracted from medicinal fungus Poria cocos. In this paper, we investigated the anticancer effect of PA on human chemotherapy resistant pancreatic cancer. PA triggered apoptosis in gemcitabine-resistant pancreatic cancer cells PANC-1 and MIA PaCa-2. Comparative gene expression array analysis demonstrated that endoplasmic reticulum (ER) stress was induced by PA through activation of heat shock response and unfolded protein response related genes. Induced ER stress was confirmed by increasing expression of XBP-1s, ATF4, Hsp70, CHOP and phospho-eIF2α. Moreover, ER stress inhibitor tauroursodeoxycholic acid (TUDCA) blocked PA induced apoptosis. In addition, 25 mg kg-1 of PA significantly suppressed MIA PaCa-2 tumor growth in vivo without toxicity, which correlated with induction of apoptosis and expression of ER stress related proteins in tumor tissues. Taken together, growth inhibition and induction of apoptosis by PA in gemcitabine-resistant pancreatic cancer cells were associated with ER stress activation both in vitro and in vivo. PA may be potentially exploited for the use in treatment of chemotherapy resistant pancreatic cancer.

  4. Investigating the drought-stress response of hybrid poplar genotypes by metabolite profiling.

    Science.gov (United States)

    Barchet, Genoa L H; Dauwe, Rebecca; Guy, Robert D; Schroeder, William R; Soolanayakanahally, Raju Y; Campbell, Malcolm M; Mansfield, Shawn D

    2014-11-01

    Drought stress is perhaps the most commonly encountered abiotic stress plants experience in the natural environment, and it is one of the most important factors limiting plant productivity. Here, we employed untargeted metabolite profiling to examine four drought-stressed hybrid poplar (Populus spp.) genotypes for their metabolite content, using gas chromatography coupled to mass spectrometry. The primary objective of these analyses was to characterize the metabolite profile of poplar trees to assess relative drought resistance and to investigate the underlying biochemical mechanisms employed by the genotypes to combat drought. Metabolite profiling identified key metabolites that increased or decreased in relative abundance upon exposure to drought stress. Overall, amino acids, the antioxidant phenolic compounds catechin and kaempferol, as well as the osmolytes raffinose and galactinol exhibited increased abundance under drought stress, whereas metabolites involved in photorespiration, redox regulation and carbon fixation showed decreased abundance under drought stress. One clone in particular, Okanese, displayed unique responses to the imposed drought conditions. This clone was found to have higher leaf water potential, but lower growth rate relative to the other clones tested. Okanese also had lower accumulation of osmolytes such as raffinose, galactinol and proline, but higher overall levels of antioxidants such as catechin and dehydroascorbic acid. As such, it was proposed that osmotic adjustment as a mechanism for drought avoidance in this clone is not as well developed in comparison with the other clones investigated in this study, and that a possible alternative mechanism for the enhanced drought avoidance displayed by Okanese may be due to differential allocation of resources or better retention of water. PMID:24178982

  5. Oxidative stress and nucleic acid oxidation in patients with chronic kidney disease.

    Science.gov (United States)

    Sung, Chih-Chien; Hsu, Yu-Chuan; Chen, Chun-Chi; Lin, Yuh-Feng; Wu, Chia-Chao

    2013-01-01

    Patients with chronic kidney disease (CKD) have high cardiovascular mortality and morbidity and a high risk for developing malignancy. Excessive oxidative stress is thought to play a major role in elevating these risks by increasing oxidative nucleic acid damage. Oxidative stress results from an imbalance between reactive oxygen/nitrogen species (RONS) production and antioxidant defense mechanisms and can cause vascular and tissue injuries as well as nucleic acid damage in CKD patients. The increased production of RONS, impaired nonenzymatic or enzymatic antioxidant defense mechanisms, and other risk factors including gene polymorphisms, uremic toxins (indoxyl sulfate), deficiency of arylesterase/paraoxonase, hyperhomocysteinemia, dialysis-associated membrane bioincompatibility, and endotoxin in patients with CKD can inhibit normal cell function by damaging cell lipids, arachidonic acid derivatives, carbohydrates, proteins, amino acids, and nucleic acids. Several clinical biomarkers and techniques have been used to detect the antioxidant status and oxidative stress/oxidative nucleic acid damage associated with long-term complications such as inflammation, atherosclerosis, amyloidosis, and malignancy in CKD patients. Antioxidant therapies have been studied to reduce the oxidative stress and nucleic acid oxidation in patients with CKD, including alpha-tocopherol, N-acetylcysteine, ascorbic acid, glutathione, folic acid, bardoxolone methyl, angiotensin-converting enzyme inhibitor, and providing better dialysis strategies. This paper provides an overview of radical production, antioxidant defence, pathogenesis and biomarkers of oxidative stress in patients with CKD, and possible antioxidant therapies.

  6. Oxidative Stress and Nucleic Acid Oxidation in Patients with Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Chih-Chien Sung

    2013-01-01

    Full Text Available Patients with chronic kidney disease (CKD have high cardiovascular mortality and morbidity and a high risk for developing malignancy. Excessive oxidative stress is thought to play a major role in elevating these risks by increasing oxidative nucleic acid damage. Oxidative stress results from an imbalance between reactive oxygen/nitrogen species (RONS production and antioxidant defense mechanisms and can cause vascular and tissue injuries as well as nucleic acid damage in CKD patients. The increased production of RONS, impaired nonenzymatic or enzymatic antioxidant defense mechanisms, and other risk factors including gene polymorphisms, uremic toxins (indoxyl sulfate, deficiency of arylesterase/paraoxonase, hyperhomocysteinemia, dialysis-associated membrane bioincompatibility, and endotoxin in patients with CKD can inhibit normal cell function by damaging cell lipids, arachidonic acid derivatives, carbohydrates, proteins, amino acids, and nucleic acids. Several clinical biomarkers and techniques have been used to detect the antioxidant status and oxidative stress/oxidative nucleic acid damage associated with long-term complications such as inflammation, atherosclerosis, amyloidosis, and malignancy in CKD patients. Antioxidant therapies have been studied to reduce the oxidative stress and nucleic acid oxidation in patients with CKD, including alpha-tocopherol, N-acetylcysteine, ascorbic acid, glutathione, folic acid, bardoxolone methyl, angiotensin-converting enzyme inhibitor, and providing better dialysis strategies. This paper provides an overview of radical production, antioxidant defence, pathogenesis and biomarkers of oxidative stress in patients with CKD, and possible antioxidant therapies.

  7. Sch9 regulates intracellular protein ubiquitination by controlling stress responses

    Directory of Open Access Journals (Sweden)

    Beibei Qie

    2015-08-01

    Full Text Available Protein ubiquitination and the subsequent degradation are important means by which aberrant proteins are removed from cells, a key requirement for long-term survival. In this study, we found that the overall level of ubiquitinated proteins dramatically decreased as yeast cell grew from log to stationary phase. Deletion of SCH9, a gene encoding a key protein kinase for longevity control, decreased the level of ubiquitinated proteins in log phase and this effect could be reversed by restoring Sch9 function. We demonstrate here that the decrease of ubiquitinated proteins in sch9Δ cells in log phase is not caused by changes in ubiquitin expression, proteasome activity, or autophagy, but by enhanced expression of stress response factors and a decreased level of oxidative stress. Our results revealed for the first time how Sch9 regulates the level of ubiquitinated proteins and provides new insight into how Sch9 controls longevity.

  8. A tension stress loading unit designed for characterizing indentation response of single crystal silicon under tension stress

    Science.gov (United States)

    Huang, Hu; Zhao, Hongwei; Shi, Chengli; Hu, Xiaoli; Cui, Tao; Tian, Ye

    2013-09-01

    In this paper, a tension stress loading unit is designed to provide tension stress for brittle materials by combining the piezo actuator and the flexible hinge. The structure of the tension stress loading unit is analyzed and discussed via the theoretical method and finite element simulations. Effects of holding time, the installed specimen and hysteresis of the piezo actuator on output performances of the tension stress loading unit are studied in detail. An experiment system is established by combing the indentation testing unit and the developed tension stress loading unit to characterize indentation response of single crystal silicon under tension stress. Experiment results indicate that tension stress leads to increasing of indentation displacement for the same inden-tation load of single crystal silicon. This paper provides a new tool for studying indentation response of brittle materials under tension stress.

  9. Crucial roles of the pentatricopeptide repeat protein SOAR1 in Arabidopsis response to drought, salt and cold stresses.

    Science.gov (United States)

    Jiang, Shang-Chuan; Mei, Chao; Liang, Shan; Yu, Yong-Tao; Lu, Kai; Wu, Zhen; Wang, Xiao-Fang; Zhang, Da-Peng

    2015-07-01

    Whereas several mitochondrial/chloroplast pentatricopeptide repeat (PPR) proteins have been reported to regulate plant responses to abiotic stresses, no nucleus-localized PPR protein has been found to play role in these processes. In the present experiment, we provide evidence that a cytosol-nucleus dual-localized PPR protein SOAR1, functioning to negatively regulate abscisic acid (ABA) signaling in seed germination and postgermination growth, is a crucial, positive regulator of plant response to abiotic stresses. Downregulation of SOAR1 expression reduces, but upregulation of SOAR1 expression enhances, ABA sensitivity in ABA-induced promotion of stomatal closure and inhibition of stomatal opening, and plant tolerance to multiple, major abiotic stresses including drought, high salinity and low temperature. Interestingly and importantly, the SOAR1-overexpression lines display strong abilities to tolerate drought, salt and cold stresses, with surprisingly high resistance to salt stress in germination and postgermination growth of seeds that are able to potentially germinate in seawater, while no negative effect on plant growth and development was observed. So, the SOAR1 gene is likely useful for improvement of crops by transgenic manipulation to enhance crop productivity in stressful conditions. Further experimental data suggest that SOAR1 likely regulates plant stress responses at least partly by integrating ABA-dependent and independent signaling pathways, which is different from the ABI2/ABI1 type 2C protein phosphatase-mediated ABA signaling. These findings help to understand highly complicated stress and ABA signalling network. PMID:26093896

  10. Fatty acids and oxidative stress in psychiatric disorders

    OpenAIRE

    Tonello Lucio; Cocchi Massimo; Tsaluchidu Sofia; Puri Basant K

    2008-01-01