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Sample records for heat stress response

  1. The Chlamydomonas heat stress response.

    PubMed

    Schroda, Michael; Hemme, Dorothea; Mühlhaus, Timo

    2015-05-01

    Heat waves occurring at increased frequency as a consequence of global warming jeopardize crop yield safety. One way to encounter this problem is to genetically engineer crop plants toward increased thermotolerance. To identify entry points for genetic engineering, a thorough understanding of how plant cells perceive heat stress and respond to it is required. Using the unicellular green alga Chlamydomonas reinhardtii as a model system to study the fundamental mechanisms of the plant heat stress response has several advantages. Most prominent among them is the suitability of Chlamydomonas for studying stress responses system-wide and in a time-resolved manner under controlled conditions. Here we review current knowledge on how heat is sensed and signaled to trigger temporally and functionally grouped sub-responses termed response elements to prevent damage and to maintain cellular homeostasis in plant cells. PMID:25754362

  2. Human Cardiovascular Responses to Passive Heat Stress

    PubMed Central

    Crandall, Craig G.; Wilson, Thad E.

    2016-01-01

    Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur. PMID:25589263

  3. Human cardiovascular responses to passive heat stress.

    PubMed

    Crandall, Craig G; Wilson, Thad E

    2015-01-01

    Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur. PMID:25589263

  4. Plant Heat Adaptation: priming in response to heat stress

    PubMed Central

    Bäurle, Isabel

    2016-01-01

    Abiotic stress is a major threat to crop yield stability. Plants can be primed by heat stress, which enables them to subsequently survive temperatures that are lethal to a plant in the naïve state. This is a rapid response that has been known for many years and that is highly conserved across kingdoms. Interestingly, recent studies in Arabidopsis and rice show that this thermo-priming lasts for several days at normal growth temperatures and that it is an active process that is genetically separable from the priming itself. This is referred to as maintenance of acquired thermotolerance or heat stress memory. Such a memory conceivably has adaptive advantages under natural conditions, where heat stress often is chronic or recurring. In this review, I will focus on recent advances in the mechanistic understanding of heat stress memory. PMID:27134736

  5. Molecular mechanisms of the plant heat stress response

    SciTech Connect

    Qu, Ai-Li; Ding, Yan-Fei; Jiang, Qiong; Zhu, Cheng

    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.

  6. Proteomics Analysis of Alfalfa Response to Heat Stress

    PubMed Central

    Li, Weimin; Wei, Zhenwu; Qiao, Zhihong; Wu, Zinian; Cheng, Lixiang; Wang, Yuyang

    2013-01-01

    The proteome responses to heat stress have not been well understood. In this study, alfalfa (Medicago sativa L. cv. Huaiyin) seedlings were exposed to 25°C (control) and 40°C (heat stress) in growth chambers, and leaves were collected at 24, 48 and 72 h after treatment, respectively. The morphological, physiological and proteomic processes were negatively affected under heat stress. Proteins were extracted and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE), and differentially expressed protein spots were identified by mass spectrometry (MS). Totally, 81 differentially expressed proteins were identified successfully by MALDI-TOF/TOF. These proteins were categorized into nine classes: including metabolism, energy, protein synthesis, protein destination/storage, transporters, intracellular traffic, cell structure, signal transduction and disease/defence. Five proteins were further analyzed for mRNA levels. The results of the proteomics analyses provide a better understanding of the molecular basis of heat-stress responses in alfalfa. PMID:24324825

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

    PubMed

    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

  8. Chloroplast Retrograde Regulation of Heat Stress Responses in Plants

    PubMed Central

    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

  9. Carotid baroreflex responsiveness in heat-stressed humans

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.

    2000-01-01

    The effects of whole body heating on human baroreflex function are relatively unknown. The purpose of this project was to identify whether whole body heating reduces the maximal slope of the carotid baroreflex. In 12 subjects, carotid-vasomotor and carotid-cardiac baroreflex responsiveness were assessed in normothermia and during whole body heating. Whole body heating increased sublingual temperature (from 36.4 +/- 0.1 to 37.4 +/- 0.1 degrees C, P < 0.01) and increased heart rate (from 59 +/- 3 to 83 +/- 3 beats/min, P < 0. 01), whereas mean arterial blood pressure (MAP) was slightly decreased (from 88 +/- 2 to 83 +/- 2 mmHg, P < 0.01). Carotid-vasomotor and carotid-cardiac responsiveness were assessed by identifying the maximal gain of MAP and heart rate to R wave-triggered changes in carotid sinus transmural pressure. Whole body heating significantly decreased the responsiveness of the carotid-vasomotor baroreflex (from -0.20 +/- 0.02 to -0.13 +/- 0.02 mmHg/mmHg, P < 0.01) without altering the responsiveness of the carotid-cardiac baroreflex (from -0.40 +/- 0.05 to -0.36 +/- 0.02 beats x min(-1) x mmHg(-1), P = 0.21). Carotid-vasomotor and carotid-cardiac baroreflex curves were shifted downward and upward, respectively, to accommodate the decrease in blood pressure and increase in heart rate that accompanied the heat stress. Moreover, the operating point of the carotid-cardiac baroreflex was shifted closer to threshold (P = 0.02) by the heat stress. Reduced carotid-vasomotor baroreflex responsiveness, coupled with a reduction in the functional reserve for the carotid baroreflex to increase heart rate during a hypotensive challenge, may contribute to increased susceptibility to orthostatic intolerance during a heat stress.

  10. Physiological responses of heat-stressed broilers fed nicarbazin.

    PubMed

    Beers, K W; Raup, T J; Bottje, W G; Odom, T W

    1989-03-01

    Two experiments were conducted to determine physiological responses in heat-stressed broilers fed a control diet or one containing 125 ppm Nicarbazin. Male birds were surgically implanted with a carotid catheter and fitted with a chest movement transducer and rectal probe. In Experiment 1, birds were exposed to an abrupt change from thermoneutral (22.5 C, 70% relative humidity [RH]) to heat stress (37 C and 40 to 50% RH) conditions within 10 min and maintained in this environment for 120 min. In Experiment 2, birds were exposed to a gradual change from thermoneutral to heat stress (38 C, 68% RH) conditions over 4 h and maintained in this environment for an additional 1 h. Heart rate (HR), respiration rate (RR), and body temperature (Tb) were monitored throughout each experiment, and arterial samples were obtained for determination of acid-base balance and lactate. Birds fed Nicarbazin had higher (P less than .05) Tb and lower (P less than .05) blood PCO2 and bicarbonate during heat stress than controls in both experiments. Thermal polypnea was observed in both experiments, but, although there were no treatment differences in Experiment 1, RR was lower (P less than .05) in the last hour of heat stress for Nicarbazin-fed birds in Experiment 2. In the second experiment, birds fed Nicarbazin exhibited higher (P less than .05) HR and blood lactate during heat stress than control-fed birds. The results of this study indicate that Nicarbazin, by an as yet unidentified mechanism, increases Tb in heat-stressed birds, which results in greater deviations in blood acid-base balance, blood lactate, and HR than in control-fed birds. PMID:2704700

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

    PubMed Central

    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. PMID:26904076

  12. Peripheral vascular responses to heat stress after hindlimb suspension

    NASA Technical Reports Server (NTRS)

    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.

  13. Quantifying livestock responses for heat stress management: a review

    NASA Astrophysics Data System (ADS)

    Nienaber, J. A.; Hahn, G. L.; Eigenberg, R. A.

    Hot weather challenges livestock production but technology exists to offset the challenge if producers have made appropriate strategic decisions. Key issues include understanding the hazards of heat stress, being prepared to offer relief from the heat, recognizing when an animal is in danger, and taking appropriate action. This paper describes our efforts to develop biological response functions; assesses climatic probabilities and performs associated risk analyses; provides inputs for computer models used to make environmental management decisions; and evaluates threshold temperatures as estimates of critical temperature limits for swine, cattle and sheep.

  14. Quantifying livestock responses for heat stress management: a review.

    PubMed

    Nienaber, J A; Hahn, G L; Eigenberg, R A

    1999-04-01

    Hot weather challenges livestock production but technology exists to offset the challenge if producers have made appropriate strategic decisions. Key issues include understanding the hazards of heat stress, being prepared to offer relief from the heat, recognizing when an animal is in danger, and taking appropriate action. This paper describes our efforts to develop biological response functions; assesses climatic probabilities and performs associated risk analyses; provides inputs for computer models used to make environmental management decisions; and evaluates threshold temperatures as estimates of critical temperature limits for swine, cattle and sheep. PMID:10232054

  15. Inhibition of the oxidative stress response by heat stress in Caenorhabditis elegans.

    PubMed

    Crombie, Timothy A; Tang, Lanlan; Choe, Keith P; Julian, David

    2016-07-15

    It has long been recognized that simultaneous exposure to heat stress and oxidative stress shows a synergistic interaction that reduces organismal fitness, but relatively little is known about the mechanisms underlying this interaction. We investigated the role of molecular stress responses in driving this synergistic interaction using the nematode Caenorhabditis elegans To induce oxidative stress, we used the pro-oxidant compounds acrylamide, paraquat and juglone. As expected, we found that heat stress and oxidative stress interact synergistically to reduce survival. Compared with exposure to each stressor alone, during simultaneous sublethal exposure to heat stress and oxidative stress the normal induction of key oxidative-stress response (OxSR) genes was generally inhibited, whereas the induction of key heat-shock response (HSR) genes was not. Genetically activating the SKN-1-dependent OxSR increased a marker for protein aggregation and decreased whole-worm survival during heat stress alone, with the latter being independent of HSF-1. In contrast, compared with wild-type worms, inactivating the HSR by HSF-1 knockdown, which would be expected to decrease basal heat shock protein expression, increased survival during oxidative stress alone. Taken together, these data suggest that, in C. elegans, the HSR and OxSR cannot be simultaneously activated to the same extent that each can be activated during a single stressor exposure. We conclude that the observed synergistic reduction in survival during combined exposure to heat stress and oxidative stress is due, at least in part, to inhibition of the OxSR during activation of the HSR. PMID:27207646

  16. Heat Stress

    MedlinePlus

    ... Stress Learn some tips to protect workers including: acclimatization, rest breaks, and fluid recommendations. NIOSH Workplace Solution: ... Blog: Adjusting to Work in the Heat: Why Acclimatization Matters The natural adaptation to the heat takes ...

  17. Can intradermal administration of angiotensin II influence human heat loss responses during whole body heat stress?

    PubMed Central

    Fujii, Naoto; Meade, Robert D.; Paull, Gabrielle; McGinn, Ryan; Foudil-bey, Imane; Akbari, Pegah

    2015-01-01

    It is unclear if angiotensin II, which can increase the production of reactive oxygen species (oxidative stress), modulates heat loss responses of cutaneous blood flow and sweating. We tested the hypothesis that angiotensin II-induced increases in oxidative stress impair cutaneous perfusion and sweating during rest and exercise in the heat. Eleven young (24 ± 4 yr) healthy adults performed two 30-min cycling bouts at a fixed rate of metabolic heat production (400 W) in the heat (35°C). The first and second exercises were followed by a 20- and 40-min recovery. Four microdialysis fibers were placed in the forearm skin for continuous administration of either: 1) lactated Ringer (control), 2) 10 μM angiotensin II, 3) 10 mM ascorbate (an antioxidant), or 4) a combination of 10 μM angiotensin II + 10 mM ascorbate. Cutaneous vascular conductance (CVC; laser-Doppler perfusion units/mean arterial pressure) and sweating (ventilated capsule) were evaluated at each skin site. Compared with control, angiotensin II reduced both CVC and sweating at baseline resting and during each recovery in the heat (all P < 0.05). However, during both exercise bouts, there were no differences in CVC or sweating between the treatment sites (all P > 0.05). When ascorbate was coinfused with angiotensin II, the effect of angiotensin II on sweating was abolished (all P > 0.05); however, its effect on CVC at baseline resting and during each recovery remained intact (all P < 0.05). We show angiotensin II impairs cutaneous perfusion independent of oxidative stress, while it impairs sweating through increasing oxidative stress during exposure to an ambient heat stress before and following exercise. PMID:25767030

  18. Can intradermal administration of angiotensin II influence human heat loss responses during whole body heat stress?

    PubMed

    Fujii, Naoto; Meade, Robert D; Paull, Gabrielle; McGinn, Ryan; Foudil-bey, Imane; Akbari, Pegah; Kenny, Glen P

    2015-05-01

    It is unclear if angiotensin II, which can increase the production of reactive oxygen species (oxidative stress), modulates heat loss responses of cutaneous blood flow and sweating. We tested the hypothesis that angiotensin II-induced increases in oxidative stress impair cutaneous perfusion and sweating during rest and exercise in the heat. Eleven young (24 ± 4 yr) healthy adults performed two 30-min cycling bouts at a fixed rate of metabolic heat production (400 W) in the heat (35°C). The first and second exercises were followed by a 20- and 40-min recovery. Four microdialysis fibers were placed in the forearm skin for continuous administration of either: 1) lactated Ringer (control), 2) 10 μM angiotensin II, 3) 10 mM ascorbate (an antioxidant), or 4) a combination of 10 μM angiotensin II + 10 mM ascorbate. Cutaneous vascular conductance (CVC; laser-Doppler perfusion units/mean arterial pressure) and sweating (ventilated capsule) were evaluated at each skin site. Compared with control, angiotensin II reduced both CVC and sweating at baseline resting and during each recovery in the heat (all P < 0.05). However, during both exercise bouts, there were no differences in CVC or sweating between the treatment sites (all P > 0.05). When ascorbate was coinfused with angiotensin II, the effect of angiotensin II on sweating was abolished (all P > 0.05); however, its effect on CVC at baseline resting and during each recovery remained intact (all P < 0.05). We show angiotensin II impairs cutaneous perfusion independent of oxidative stress, while it impairs sweating through increasing oxidative stress during exposure to an ambient heat stress before and following exercise. PMID:25767030

  19. Chronic Heat Stress Induces Immune Response, Oxidative Stress Response, and Apoptosis of Finishing Pig Liver: A Proteomic Approach

    PubMed Central

    Cui, Yanjun; Hao, Yue; Li, Jielei; Bao, Weiguang; Li, Gan; Gao, Yanli; Gu, Xianhong

    2016-01-01

    Heat stress (HS) negatively affects human health, animal welfare, and livestock production. We analyzed the hepatic proteomes of finishing pigs subjected to chronic heat stress (HS), thermal neutral (TN), and restricted feed intake conditions, identifying differences between direct and indirect (via reduced feed intake) HS. Twenty-four castrated male pigs were randomly allocated to three treatments for three weeks: (1) thermal neutral (TN) (22 °C) with ad libitum feeding; (2) chronic HS (30 °C) with ad libitum feeding; and (3) TN, pair-fed to HS intake (PF). Hepatic proteome analysis was conducted using two-dimensional gel electrophoresis and mass spectrometry. Both HS and PF significantly reduced liver weight (p < 0.05). Forty-five hepatic proteins were differentially abundant when comparing HS with TN (37), PF with TN (29), and HS with PF (16). These proteins are involved in heat shock response and immune defense, oxidative stress response, cellular apoptosis, metabolism, signal transduction, and cytoskeleton. We also observed increased abundance of proteins and enzymes associated with heat shock response and immune defense, reduced the redox state, enhanced multiple antioxidant abilities, and increased apoptosis in HS liver. Heat-load, independent of reduced feed intake, induced an innate immune response, while food restriction caused stress and cellular apoptosis. Our results provide novel insights into the effects of chronic HS on liver. PMID:27187351

  20. Chronic Heat Stress Induces Immune Response, Oxidative Stress Response, and Apoptosis of Finishing Pig Liver: A Proteomic Approach.

    PubMed

    Cui, Yanjun; Hao, Yue; Li, Jielei; Bao, Weiguang; Li, Gan; Gao, Yanli; Gu, Xianhong

    2016-01-01

    Heat stress (HS) negatively affects human health, animal welfare, and livestock production. We analyzed the hepatic proteomes of finishing pigs subjected to chronic heat stress (HS), thermal neutral (TN), and restricted feed intake conditions, identifying differences between direct and indirect (via reduced feed intake) HS. Twenty-four castrated male pigs were randomly allocated to three treatments for three weeks: (1) thermal neutral (TN) (22 °C) with ad libitum feeding; (2) chronic HS (30 °C) with ad libitum feeding; and (3) TN, pair-fed to HS intake (PF). Hepatic proteome analysis was conducted using two-dimensional gel electrophoresis and mass spectrometry. Both HS and PF significantly reduced liver weight (p < 0.05). Forty-five hepatic proteins were differentially abundant when comparing HS with TN (37), PF with TN (29), and HS with PF (16). These proteins are involved in heat shock response and immune defense, oxidative stress response, cellular apoptosis, metabolism, signal transduction, and cytoskeleton. We also observed increased abundance of proteins and enzymes associated with heat shock response and immune defense, reduced the redox state, enhanced multiple antioxidant abilities, and increased apoptosis in HS liver. Heat-load, independent of reduced feed intake, induced an innate immune response, while food restriction caused stress and cellular apoptosis. Our results provide novel insights into the effects of chronic HS on liver. PMID:27187351

  1. Genetic variations alter production and behavioral responses following heat stress in two strains of laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress is a problem for both egg production and hen well-being. Given a stressor, genetic differences alter the type and degree of hens’ responses and their adaptation. This study examined heat stress responses of two strains of White Leghorns: Dekalb XL (DXL), a commercial strain individually ...

  2. Genome scale transcriptional response diversity among ten ecotypes of Arabidopsis thaliana during heat stress

    PubMed Central

    Barah, Pankaj; Jayavelu, Naresh D.; Mundy, John; Bones, Atle M.

    2013-01-01

    In the scenario of global warming and climate change, heat stress is a serious threat to crop production worldwide. Being sessile, plants cannot escape from heat. Plants have developed various adaptive mechanisms to survive heat stress. Several studies have focused on diversity of heat tolerance levels in divergent Arabidopsis thaliana (A. thaliana) ecotypes, but comprehensive genome scale understanding of heat stress response in plants is still lacking. Here we report the genome scale transcript responses to heat stress of 10 A. thaliana ecotypes (Col, Ler, C24, Cvi, Kas1, An1, Sha, Kyo2, Eri, and Kond) originated from different geographical locations. During the experiment, A. thaliana plants were subjected to heat stress (38°C) and transcript responses were monitored using Arabidopsis NimbleGen ATH6 microarrays. The responses of A. thaliana ecotypes exhibited considerable variation in the transcript abundance levels. In total, 3644 transcripts were significantly heat regulated (p < 0.01) in the 10 ecotypes, including 244 transcription factors and 203 transposable elements. By employing a systems genetics approach- Network Component Analysis (NCA), we have constructed an in silico transcript regulatory network model for 35 heat responsive transcription factors during cellular responses to heat stress in A. thaliana. The computed activities of the 35 transcription factors showed ecotype specific responses to the heat treatment. PMID:24409190

  3. Identification of heat stress-responsive genes in heat-adapted thermal Agrostis scabra by suppression subtractive hybridization.

    PubMed

    Tian, Jiang; Belanger, Faith C; Huang, Bingru

    2009-04-01

    To gain insights into molecular mechanisms of grass tolerance to heat stress, we constructed a suppression subtractive cDNA library to identify heat-responsive genes for a C(3) grass species, thermal Agrostis scabra adapted to heat stress in geothermal areas in Yellowstone National Park. Plants were exposed to 20 degrees C (control) or 35 degrees C for 12d. The SSH analysis was performed with control samples as the driver and heat-stressed samples as the tester. Differentially expressed cDNA fragments were cloned to screen the heat up-regulated library. The SSH analysis identified 120 non-redundant putative heat-responsive cDNAs out of 1180 clones. Genes with homology to known proteins were categorized into six functional groups, with the largest group of genes involved in stress/defense, followed by the group of genes related to protein metabolism. Immunoblot analysis confirmed increases in transcripts of selected genes under heat stress. Transcripts of seven and eight genes were strongly enhanced or induced in shoots and roots, respectively, while two genes were only induced in roots under heat stress. The heat up-regulated genes in thermal A. scabra adapted to long-term heat stress are potential candidate genes for engineering stress-tolerant grasses and for revealing molecular mechanisms of grass adaptation to heat stress. PMID:18950897

  4. Regulation of Non-coding RNAs in Heat Stress Responses of Plants

    PubMed Central

    Zhao, Jianguo; He, Qingsong; Chen, Gang; Wang, Li; Jin, Biao

    2016-01-01

    Heat stress is an important factor limiting plant growth, development, and productivity; thus, plants have evolved special adaptive mechanisms to cope with high-temperature stress. Non-coding RNAs (ncRNAs) are a class of regulatory RNAs that play an important role in many biological processes. Recently developed advanced technologies, such as genome-wide transcriptomic analysis, have revealed that abundant ncRNAs are expressed under heat stress. Although this area of research is still in its infancy, an increasing number of several classes of regulatory ncRNA (i.e., miRNA, siRNA, and lncRNA) related to heat stress responses have been reported. In this mini-review, we discuss our current understanding of the role of ncRNAs in heat stress responses in plants, especially miRNAs, siRNAs, and their targets. For example, the miR398-CSD/CCS-HSF, miR396-WRKY6, miR159-GAMYB, and TAS1-HTT-HSF pathways regulate plant heat tolerance. We highlight the hormone/development-related miRNAs involved in heat stress, and discuss the regulatory networks of miRNA-targets. We also note that DNA methylation and alternative splicing could affect miRNA expression under heat stress, and some lncRNAs could respond to heat stress. Finally, we briefly discuss future prospects concerning the ncRNA-related mechanisms of heat stress responses in plants. PMID:27588021

  5. Regulation of Non-coding RNAs in Heat Stress Responses of Plants.

    PubMed

    Zhao, Jianguo; He, Qingsong; Chen, Gang; Wang, Li; Jin, Biao

    2016-01-01

    Heat stress is an important factor limiting plant growth, development, and productivity; thus, plants have evolved special adaptive mechanisms to cope with high-temperature stress. Non-coding RNAs (ncRNAs) are a class of regulatory RNAs that play an important role in many biological processes. Recently developed advanced technologies, such as genome-wide transcriptomic analysis, have revealed that abundant ncRNAs are expressed under heat stress. Although this area of research is still in its infancy, an increasing number of several classes of regulatory ncRNA (i.e., miRNA, siRNA, and lncRNA) related to heat stress responses have been reported. In this mini-review, we discuss our current understanding of the role of ncRNAs in heat stress responses in plants, especially miRNAs, siRNAs, and their targets. For example, the miR398-CSD/CCS-HSF, miR396-WRKY6, miR159-GAMYB, and TAS1-HTT-HSF pathways regulate plant heat tolerance. We highlight the hormone/development-related miRNAs involved in heat stress, and discuss the regulatory networks of miRNA-targets. We also note that DNA methylation and alternative splicing could affect miRNA expression under heat stress, and some lncRNAs could respond to heat stress. Finally, we briefly discuss future prospects concerning the ncRNA-related mechanisms of heat stress responses in plants. PMID:27588021

  6. Plastic and evolutionary responses to heat stress in a temperate dung fly: negative correlation between basal and induced heat tolerance?

    PubMed

    Esperk, T; Kjaersgaard, A; Walters, R J; Berger, D; Blanckenhorn, W U

    2016-05-01

    Extreme weather events such as heat waves are becoming more frequent and intense. Populations can cope with elevated heat stress by evolving higher basal heat tolerance (evolutionary response) and/or stronger induced heat tolerance (plastic response). However, there is ongoing debate about whether basal and induced heat tolerance are negatively correlated and whether adaptive potential in heat tolerance is sufficient under ongoing climate warming. To evaluate the evolutionary potential of basal and induced heat tolerance, we performed experimental evolution on a temperate source population of the dung fly Sepsis punctum. Offspring of flies adapted to three thermal selection regimes (Hot, Cold and Reference) were subjected to acute heat stress after having been exposed to either a hot-acclimation or non-acclimation pretreatment. As different traits may respond differently to temperature stress, several physiological and life history traits were assessed. Condition dependence of the response was evaluated by exposing juveniles to different levels of developmental (food restriction/rearing density) stress. Heat knockdown times were highest, whereas acclimation effects were lowest in the Hot selection regime, indicating a negative association between basal and induced heat tolerance. However, survival, adult longevity, fecundity and fertility did not show such a pattern. Acclimation had positive effects in heat-shocked flies, but in the absence of heat stress hot-acclimated flies had reduced life spans relative to non-acclimated ones, thereby revealing a potential cost of acclimation. Moreover, body size positively affected heat tolerance and unstressed individuals were less prone to heat stress than stressed flies, offering support for energetic costs associated with heat tolerance. Overall, our results indicate that heat tolerance of temperate insects can evolve under rising temperatures, but this response could be limited by a negative relationship between basal and

  7. Testing the responses of four wheat crop models to heat stress at anthesis and grain filling.

    PubMed

    Liu, Bing; Asseng, Senthold; Liu, Leilei; Tang, Liang; Cao, Weixing; Zhu, Yan

    2016-05-01

    Higher temperatures caused by future climate change will bring more frequent heat stress events and pose an increasing risk to global wheat production. Crop models have been widely used to simulate future crop productivity but are rarely tested with observed heat stress experimental datasets. Four wheat models (DSSAT-CERES-Wheat, DSSAT-Nwheat, APSIM-Wheat, and WheatGrow) were evaluated with 4 years of environment-controlled phytotron experimental datasets with two wheat cultivars under heat stress at anthesis and grain filling stages. Heat stress at anthesis reduced observed grain numbers per unit area and individual grain size, while heat stress during grain filling mainly decreased the size of the individual grains. The observed impact of heat stress on grain filling duration, total aboveground biomass, grain yield, and grain protein concentration (GPC) varied depending on cultivar and accumulated heat stress. For every unit increase of heat degree days (HDD, degree days over 30 °C), grain filling duration was reduced by 0.30-0.60%, total aboveground biomass was reduced by 0.37-0.43%, and grain yield was reduced by 1.0-1.6%, but GPC was increased by 0.50% for cv Yangmai16 and 0.80% for cv Xumai30. The tested crop simulation models could reproduce some of the observed reductions in grain filling duration, final total aboveground biomass, and grain yield, as well as the observed increase in GPC due to heat stress. Most of the crop models tended to reproduce heat stress impacts better during grain filling than at anthesis. Some of the tested models require improvements in the response to heat stress during grain filling, but all models need improvements in simulating heat stress effects on grain set during anthesis. The observed significant genetic variability in the response of wheat to heat stress needs to be considered through cultivar parameters in future simulation studies. PMID:26725507

  8. Comparison of heat dissipation response between Malaysian and Japanese males during exercise in humid heat stress

    NASA Astrophysics Data System (ADS)

    Wakabayashi, Hitoshi; Wijayanto, Titis; Lee, Joo-Young; Hashiguchi, Nobuko; Saat, Mohamed; Tochihara, Yutaka

    2011-07-01

    This study investigated the differences in heat dissipation response to intense heat stress during exercise in hot and humid environments between tropical and temperate indigenes with matched physical characteristics. Ten Japanese (JP) and ten Malaysian (MY) males participated in this study. Subjects performed exercise for 60 min at 55% peak oxygen uptake in 32°C air with 70% relative humidity, followed by 30 min recovery. The increase in rectal temperature ( T re) was smaller in MY during exercise compared to JP. The local sweat rate and total body mass loss were similar in both groups. Both skin blood flow and mean skin temperature was lower in MY compared to JP. A significantly greater increase in hand skin temperature was observed in MY during exercise, which is attributable to heat loss due to the greater surface area to mass ratio and large number of arteriovenous anastomoses. Also, the smaller increase in T re in MY may be explained by the presence of a significantly greater core-skin temperature gradient in MY than JP. The thermal gradient is also a major factor in increasing the convective heat transfer from core to skin as well as skin blood flow. It is concluded that the greater core-skin temperature gradient observed in MY is responsible for the smaller increase in T re.

  9. Histological, ultrastructural and heat shock protein 70 (HSP70) responses to heat stress in the sea cucumber Apostichopus japonicus.

    PubMed

    Xu, Dongxue; Sun, Lina; Liu, Shilin; Zhang, Libin; Yang, Hongsheng

    2015-08-01

    The aquaculture industry for Apostichopus japonicus has suffered severe economic and resource losses due to high temperature in recent summers. There is increasing concern about the effect of high temperature on this species. Histological, ultrastructural and HSP70 responses to heat stress were investigated in the intestine of A. japonicus. Tissue degradation was observed in muscular, submucosal and mucosal layers, with significant decrease in plicae circulares of the mucosal layer. Ultrastructural damage intensified with increasing stress time, and indicators of cell apoptosis were evident after 192 h heat stress. Immunostaining showed HSP70 mainly in mucosa and serosa, with faint staining in non-stressed individuals (the control group) and denser staining under stress (the 6, 48 and 192 h groups). Western blot detection confirmed ocurrence of HSP70 in all groups and significant up-regulation under stress. The rapid and persistent response of HSP70 implies its critical role in the heat shock response of A. japonicus. PMID:25917397

  10. Epigenetic responses to heat stress at different time scales and the involvement of small RNAs

    PubMed Central

    Stief, Anna; Brzezinka, Krzysztof; Lämke, Jörn; Bäurle, Isabel

    2014-01-01

    The hypothesis that plants can benefit from a memory of past stress exposure has recently attracted a lot of attention. Here, we discuss two different examples of heat stress memory to elucidate the potential benefits that epigenetic responses may provide at both the level of acclimation of the individual plant and adaptation at a species-wide level. Specifically, we discuss how microRNAs regulate the heat stress memory and thereby increase survival upon a recurring heat stress. Secondly, we review how a prolonged heat stress in a small interfering RNA-deficient background induces retrotransposition that is transmitted to the next generation, thus creating genetic variation for natural selection to act on. Collectively, these studies reveal a crucial role of short RNAs in heat stress memory across different time scales. PMID:25482804

  11. Phosphoproteomic analysis of the response of maize leaves to drought, heat and their combination stress

    PubMed Central

    Hu, Xiuli; Wu, Liuji; Zhao, Feiyun; Zhang, Dayong; Li, Nana; Zhu, Guohui; Li, Chaohao; Wang, Wei

    2015-01-01

    Drought and heat stress, especially their combination, greatly affect crop production. Many studies have described transcriptome, proteome and phosphoproteome changes in response of plants to drought or heat stress. However, the study about the phosphoproteomic changes in response of crops to the combination stress is scare. To understand the mechanism of maize responses to the drought and heat combination stress, phosphoproteomic analysis was performed on maize leaves by using multiplex iTRAQ-based quantitative proteomic and LC-MS/MS methods. Five-leaf-stage maize was subjected to drought, heat or their combination, and the leaves were collected. Globally, heat, drought and the combined stress significantly changed the phosphorylation levels of 172, 149, and 144 phosphopeptides, respectively. These phosphopeptides corresponded to 282 proteins. Among them, 23 only responded to the combined stress and could not be predicted from their responses to single stressors; 30 and 75 only responded to drought and heat, respectively. Notably, 19 proteins were phosphorylated on different sites in response to the single and combination stresses. Of the seven significantly enriched phosphorylation motifs identified, two were common for all stresses, two were common for heat and the combined stress, and one was specific to the combined stress. The signaling pathways in which the phosphoproteins were involved clearly differed among the three stresses. Functional characterization of the phosphoproteins and the pathways identified here could lead to new targets for the enhancement of crop stress tolerance, which will be particularly important in the face of climate change and the increasing prevalence of abiotic stressors. PMID:25999967

  12. Use of heat stress responsive gene expression levels for early selection of heat tolerant cabbage (Brassica oleracea L.).

    PubMed

    Park, Hyun Ji; Jung, Won Yong; Lee, Sang Sook; Song, Jun Ho; Kwon, Suk-Yoon; Kim, Hyeran; Kim, Chulwook; Ahn, Jun Cheul; Cho, Hye Sun

    2013-01-01

    Cabbage is a relatively robust vegetable at low temperatures. However, at high temperatures, cabbage has disadvantages, such as reduced disease tolerance and lower yields. Thus, selection of heat-tolerant cabbage is an important goal in cabbage breeding. Easier or faster selection of superior varieties of cabbage, which are tolerant to heat and disease and have improved taste and quality, can be achieved with molecular and biological methods. We compared heat-responsive gene expression between a heat-tolerant cabbage line (HTCL), "HO", and a heat-sensitive cabbage line (HSCL), "JK", by Genechip assay. Expression levels of specific heat stress-related genes were increased in response to high-temperature stress, according to Genechip assays. We performed quantitative RT-PCR (qRT-PCR) to compare expression levels of these heat stress-related genes in four HTCLs and four HSCLs. Transcript levels for heat shock protein BoHsp70 and transcription factor BoGRAS (SCL13) were more strongly expressed only in all HTCLs compared to all HSCLs, showing much lower level expressions at the young plant stage under heat stress (HS). Thus, we suggest that expression levels of these genes may be early selection markers for HTCLs in cabbage breeding. In addition, several genes that are involved in the secondary metabolite pathway were differentially regulated in HTCL and HSCL exposed to heat stress. PMID:23736694

  13. Gene expression changes in response to aging compared to heat stress, oxidative stress and ionizing radiation in Drosophila melanogaster

    PubMed Central

    Landis, Gary; Tower, John

    2012-01-01

    Gene expression changes in response to aging, heat stress, hyperoxia, hydrogen peroxide, and ionizing radiation were compared using microarrays. A set of 18 genes were up-regulated across all conditions, indicating a general stress response shared with aging, including the heat shock protein (Hsp) genes Hsp70, Hsp83 and l(2)efl, the glutathione-S-transferase gene GstD2, and the mitochondrial unfolded protein response (mUPR) gene ref(2)P. Selected gene expression changes were confirmed using quantitative PCR, Northern analysis and GstD-GFP reporter constructs. Certain genes were altered in only a subset of the conditions, for example, up-regulation of numerous developmental pathway and signaling genes in response to hydrogen peroxide. While aging shared features with each stress, aging was more similar to the stresses most associated with oxidative stress (hyperoxia, hydrogen peroxide, ionizing radiation) than to heat stress. Aging is associated with down-regulation of numerous mitochondrial genes, including electron-transport-chain (ETC) genes and mitochondrial metabolism genes, and a sub-set of these changes was also observed upon hydrogen peroxide stress and ionizing radiation stress. Aging shared the largest number of gene expression changes with hyperoxia. The extensive down-regulation of mitochondrial and ETC genes during aging is consistent with an aging-associated failure in mitochondrial maintenance, which may underlie the oxidative stress-like and proteotoxic stress-like responses observed during aging. PMID:23211361

  14. Chromatin changes in response to drought, salinity, heat, and cold stresses in plants

    PubMed Central

    Kim, Jong-Myong; Sasaki, Taku; Ueda, Minoru; Sako, Kaori; Seki, Motoaki

    2015-01-01

    Chromatin regulation is essential to regulate genes and genome activities. In plants, the alteration of histone modification and DNA methylation are coordinated with changes in the expression of stress-responsive genes to adapt to environmental changes. Several chromatin regulators have been shown to be involved in the regulation of stress-responsive gene networks under abiotic stress conditions. Specific histone modification sites and the histone modifiers that regulate key stress-responsive genes have been identified by genetic and biochemical approaches, revealing the importance of chromatin regulation in plant stress responses. Recent studies have also suggested that histone modification plays an important role in plant stress memory. In this review, we summarize recent progress on the regulation and alteration of histone modification (acetylation, methylation, phosphorylation, and SUMOylation) in response to the abiotic stresses, drought, high-salinity, heat, and cold in plants. PMID:25784920

  15. Boechera Species Exhibit Species-Specific Responses to Combined Heat and High Light Stress

    PubMed Central

    Gallas, Genna; Waters, Elizabeth R.

    2015-01-01

    As sessile organisms, plants must be able to complete their life cycle in place and therefore tolerance to abiotic stress has had a major role in shaping biogeographical patterns. However, much of what we know about plant tolerance to abiotic stresses is based on studies of just a few plant species, most notably the model species Arabidopsis thaliana. In this study we examine natural variation in the stress responses of five diverse Boechera (Brassicaceae) species. Boechera plants were exposed to basal and acquired combined heat and high light stress. Plant response to these stresses was evaluated based on chlorophyll fluorescence measurements, induction of leaf chlorosis, and gene expression. Many of the Boechera species were more tolerant to heat and high light stress than A. thaliana. Gene expression data indicates that two important marker genes for stress responses: APX2 (Ascorbate peroxidase 2) and HsfA2 (Heat shock transcription factor A2) have distinct species-specific expression patterns. The findings of species-specific responses and tolerance to stress indicate that stress pathways are evolutionarily labile even among closely related species. PMID:26030823

  16. Oxidative Stress and Heat-Shock Responses in Desulfovibrio vulgaris by Genome-Wide Transcriptomic Analysis

    SciTech Connect

    Zhang, Weiwen; Culley, David E.; Hogan, Mike; Vitiritti, Luigi; Brockman, Fred J.

    2006-05-30

    Abstract Sulfate-reducing bacteria, like Desulfovibrio vulgaris have developed a set of reactions allowing them to survive in environments. To obtain further knowledge of the protecting mechanisms employed in D. vulgaris against the oxidative stress and heat shock, we performed a genome-wide transcriptomic analysis to determine the cellular responses to both stimuli. The results showed that 130 genes were responsive to oxidative stress, while 427 genes responsive to heat-shock, respectively. Functional analyses suggested that the genes regulated were involved in a variety of cellular functions. Metabolic analysis showed that amino acid biosynthetic pathways were induced by both oxidative stress and heat shock treatments, while fatty acid metabolism, purine and cofactor biosynthesis were induced by heat shock only. Rubrerythrin gene (rbR) were upregulated by the oxidative stress, suggesting its important role in the oxidative resistance, whereas the expression of rubredoxin oxidoreductase (rbO), superoxide ismutase (sodB) and catalase (katA) genes were not subjected to regulation by oxidative stress in D. vulgaris. In addition, the results showed that thioredoxin reductase (trxB) was responsive to oxidative stress, suggesting the thiol-specific redox system might be involved in oxidative protection in D. vulgaris. Comparison of cellular responses to oxidative stress and heat-shock allowed the identification of 66 genes that showed a similar drastic response to both environmental stimuli, implying that they might be part of the general stress response (GSR) network in D. vulgaris, which was further supported by the finding of a conserved motif upstream these common-responsive genes.

  17. Sub-lethal heat stress causes apoptosis in an Antarctic fish that lacks an inducible heat shock response.

    PubMed

    Sleadd, Isaac M; Lee, Marissa; Hassumani, Daniel O; Stecyk, Tonya M A; Zeitz, Otto K; Buckley, Bradley A

    2014-08-01

    The endemic fish fauna of the Southern Ocean are cold-adapted stenotherms and are acutely sensitive to elevated temperature. Many of these species lack a heat shock response and cannot increase the production of heat shock proteins in their tissues. However, some species retain the ability to induce other stress-responsive genes, some of which are involved in cell cycle arrest and apoptosis. Here, the effect of heat on cell cycle stage and its ability to induce apoptosis were tested in thermally stressed hepatocytes from a common Antarctic fish species from McMurdo Sound in the Ross Sea. Levels of proliferating cell nuclear antigen were also measured as a marker of progression through the cell cycle. The results of these studies demonstrate that even sub-lethal heat stress can have deleterious impacts at the cellular level on these environmentally sensitive species. PMID:25086982

  18. Gene expression profiling of potato responses to cold, heat, and salt stress.

    PubMed

    Rensink, Willem Albert; Iobst, Stacey; Hart, Amy; Stegalkina, Svetlana; Liu, Jia; Buell, C Robin

    2005-10-01

    In order to identify genes involved in abiotic stress responses in potato, seedlings were grown under controlled conditions and subjected to cold (4 degrees C), heat (35 degrees C), or salt (100 mM NaCl) stress for up to 27 h. Using an approximately 12,000 clone potato cDNA microarray, expression profiles were captured at three time points following initiation of the stress (3, 9, and 27 h) from two different tissues, roots and leaves. A total of 3,314 clones could be identified as significantly up- or down-regulated in response to at least one stress condition. The genes represented by these clones encode transcription factors, signal transduction factors, and heat-shock proteins which have been associated with abiotic stress responses in Arabidopsis and rice, suggesting similar response pathways function in potato. These stress-regulated clones could be separated into either stress-specific or shared-response clones, suggesting the existence of general response pathways as well as more stress-specific pathways. In addition, we identified expression profiles which are indicative for the type of stress applied to the plants. PMID:15856349

  19. Transgenerational phenotypic and epigenetic changes in response to heat stress in Arabidopsis thaliana.

    PubMed

    Migicovsky, Zoë; Yao, Youli; Kovalchuk, Igor

    2014-01-01

    Exposure to heat stress causes physiological and epigenetic changes in plants, which may also be altered in the progeny. We compared the progeny of stressed and control Arabidopsis thaliana wild type and Dicer-like mutant dcl2, dcl3, and dcl4 plants for variations in physiology and molecular profile, including global genome methylation, mRNA levels, and histone modifications in the subset of differentially expressed genes at normal conditions and in response to heat stress. We found that the immediate progeny of heat-stressed plants had fewer, but larger leaves, and tended to bolt earlier. Transposon expression was elevated in the progeny of heat-stressed plants, and heat stress in the same generation tended to decrease global genome methylation. Progeny of stressed plants had increased expression of HSFA2, and reduction in MSH2, ROS1, and several SUVH genes. Gene expression positively correlated with permissive histone marks and negatively correlated with repressive marks. Overall, the progeny of heat stressed plants varied in both their physiology and epigenome and dcl2 and dcl3 mutants were partially deficient for these changes. PMID:24513700

  20. Leaf Proteome Analysis Reveals Prospective Drought and Heat Stress Response Mechanisms in Soybean.

    PubMed

    Das, Aayudh; Eldakak, Moustafa; Paudel, Bimal; Kim, Dea-Wook; Hemmati, Homa; Basu, Chhandak; Rohila, Jai S

    2016-01-01

    Drought and heat are among the major abiotic stresses that affect soybean crops worldwide. During the current investigation, the effect of drought, heat, and drought plus heat stresses was compared in the leaves of two soybean varieties, Surge and Davison, combining 2D-DIGE proteomic data with physiology and biochemical analyses. We demonstrated how 25 differentially expressed photosynthesis-related proteins affect RuBisCO regulation, electron transport, Calvin cycle, and carbon fixation during drought and heat stress. We also observed higher abundance of heat stress-induced EF-Tu protein in Surge. It is possible that EF-Tu might have activated heat tolerance mechanisms in the soybean. Higher level expressions of heat shock-related protein seem to be regulating the heat tolerance mechanisms. This study identifies the differential expression of various abiotic stress-responsive proteins that regulate various molecular processes and signaling cascades. One inevitable outcome from the biochemical and proteomics assays of this study is that increase of ROS levels during drought stress does not show significant changes at the phenotypic level in Davison and this seems to be due to a higher amount of carbonic anhydrase accumulation in the cell which aids the cell to become more resistant to cytotoxic concentrations of H2O2. PMID:27034942

  1. Leaf Proteome Analysis Reveals Prospective Drought and Heat Stress Response Mechanisms in Soybean

    PubMed Central

    Das, Aayudh; Eldakak, Moustafa; Paudel, Bimal; Kim, Dea-Wook; Hemmati, Homa; Basu, Chhandak

    2016-01-01

    Drought and heat are among the major abiotic stresses that affect soybean crops worldwide. During the current investigation, the effect of drought, heat, and drought plus heat stresses was compared in the leaves of two soybean varieties, Surge and Davison, combining 2D-DIGE proteomic data with physiology and biochemical analyses. We demonstrated how 25 differentially expressed photosynthesis-related proteins affect RuBisCO regulation, electron transport, Calvin cycle, and carbon fixation during drought and heat stress. We also observed higher abundance of heat stress-induced EF-Tu protein in Surge. It is possible that EF-Tu might have activated heat tolerance mechanisms in the soybean. Higher level expressions of heat shock-related protein seem to be regulating the heat tolerance mechanisms. This study identifies the differential expression of various abiotic stress-responsive proteins that regulate various molecular processes and signaling cascades. One inevitable outcome from the biochemical and proteomics assays of this study is that increase of ROS levels during drought stress does not show significant changes at the phenotypic level in Davison and this seems to be due to a higher amount of carbonic anhydrase accumulation in the cell which aids the cell to become more resistant to cytotoxic concentrations of H2O2. PMID:27034942

  2. Heat Stress Responses in Cultured Plant Cells 1

    PubMed Central

    Wu, Min-Tze; Wallner, Stephen J.; Waddell, John W.

    1984-01-01

    The pipetting of pear (Pyrus communis cv Bartlett) suspension cultures was followed by a substantial but transient decrease in heat sensitivity. During a culture cycle, pear cells were most sensitive to heat at day 3, which coincided with the period of most active cell division. To minimize serious artifacts, the influence of culture handling and age on parameters such as heat sensitivity must be standardized. PMID:16663538

  3. Transcriptome analysis of heat stress response in switchgrass (Panicum virgatum L.)

    PubMed Central

    2013-01-01

    Background Global warming predictions indicate that temperatures will increase by another 2-6°C by the end of this century. High temperature is a major abiotic stress limiting plant growth and productivity in many areas of the world. Switchgrass (Panicum virgatum L.) is a model herbaceous bioenergy crop, due to its rapid growth rate, reliable biomass yield, minimal requirements of water and nutrients, adaptability to grow on marginal lands and widespread distribution throughout North America. The effect of high temperature on switchgrass physiology, cell wall composition and biomass yields has been reported. However, there is void in the knowledge of the molecular responses to heat stress in switchgrass. Results We conducted long-term heat stress treatment (38°/30°C, day/night, for 50 days) in the switchgrass cultivar Alamo. A significant decrease in the plant height and total biomass was evident in the heat stressed plants compared to controls. Total RNA from control and heat stress samples were used for transcriptome analysis with switchgrass Affymetrix genechips. Following normalization and pre-processing, 5365 probesets were identified as differentially expressed using a 2-fold cutoff. Of these, 2233 probesets (2000 switchgrass unigenes) were up-regulated, and 3132 probesets (2809 unigenes) were down-regulated. Differential expression of 42 randomly selected genes from this list was validated using RT-PCR. Rice orthologs were retrieved for 78.7% of the heat stress responsive switchgrass probesets. Gene ontology (GOs) enrichment analysis using AgriGO program showed that genes related to ATPase regulator, chaperone binding, and protein folding was significantly up-regulated. GOs associated with protein modification, transcription, phosphorus and nitrogen metabolic processes, were significantly down-regulated by heat stress. Conclusions Plausible connections were identified between the identified GOs, physiological responses and heat response phenotype

  4. Gene Expression Profile in the Long-Living Lotus: Insights into the Heat Stress Response Mechanism

    PubMed Central

    Li, Naiwei; Chang, Yajun; Yao, Dongrui

    2016-01-01

    Lotus (Nelumbo Adans) is an aquatic perennial plant that flourished during the middle Albian stage. In this study, we characterized the digital gene expression signatures for China Antique lotus under conditions of heat shock stress. Using RNA-seq technology, we sequenced four libraries, specifically, two biological replicates for control plant samples and two for heat stress samples. As a result, 6,528,866 to 8,771,183 clean reads were mapped to the reference genome, accounting for 92–96% total clean reads. A total of 396 significantly altered genes were detected across the genome, among which 315 were upregulated and 81 were downregulated by heat shock stress. Gene ontology (GO) enrichment of differentially expressed genes revealed protein folding, cell morphogenesis and cellular component morphogenesis as the top three functional terms under heat shock stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis led to the identification of protein processing in endoplasmic reticulum, plant-pathogen interactions, spliceosome, endocytosis, and protein export as significantly enriched pathways. Among the upregulated genes, small heat shock proteins (sHsps) and genes related to cell morphogenesis were particularly abundant under heat stress. Data from the current study provide valuable clues that may help elucidate the molecular events underlying heat stress response in China Antique lotus. PMID:27018792

  5. Gene Expression Profile in the Long-Living Lotus: Insights into the Heat Stress Response Mechanism.

    PubMed

    Liu, Xiaojing; Du, Fengfeng; Li, Naiwei; Chang, Yajun; Yao, Dongrui

    2016-01-01

    Lotus (Nelumbo Adans) is an aquatic perennial plant that flourished during the middle Albian stage. In this study, we characterized the digital gene expression signatures for China Antique lotus under conditions of heat shock stress. Using RNA-seq technology, we sequenced four libraries, specifically, two biological replicates for control plant samples and two for heat stress samples. As a result, 6,528,866 to 8,771,183 clean reads were mapped to the reference genome, accounting for 92-96% total clean reads. A total of 396 significantly altered genes were detected across the genome, among which 315 were upregulated and 81 were downregulated by heat shock stress. Gene ontology (GO) enrichment of differentially expressed genes revealed protein folding, cell morphogenesis and cellular component morphogenesis as the top three functional terms under heat shock stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis led to the identification of protein processing in endoplasmic reticulum, plant-pathogen interactions, spliceosome, endocytosis, and protein export as significantly enriched pathways. Among the upregulated genes, small heat shock proteins (sHsps) and genes related to cell morphogenesis were particularly abundant under heat stress. Data from the current study provide valuable clues that may help elucidate the molecular events underlying heat stress response in China Antique lotus. PMID:27018792

  6. Expression of heat shock protein genes in insect stress responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The heat shock proteins (HSPs) that are abundantly expressed in insects are important modulators of insect survival. Expression of HSP genes in insects is not only developmentally regulated, but also induced by various stressors in order to confer protection against such stressors. The expression o...

  7. Whole-body heating decreases skin vascular response to low orthostatic stress in the lower extremities.

    PubMed

    Yamazaki, Fumio; Nakayama, Yoshiro; Sone, Ryoko

    2006-04-01

    To elucidate the influence of heat stress on cutaneous vascular response in the lower extremities during orthostatic stress, a head-up tilt (HUT) test at angles of 15 degrees, 30 degrees, 45 degrees, and 60 degrees for 4 min each was conducted under normothermic control conditions followed by whole-body heat stress produced by a hot water-perfused suit in healthy volunteers. Skin blood flows (SkBF) in the forearm, thigh, and calf were monitored using laser-Doppler flowmetry throughout the experiment. Furthermore, to elucidate the effects of increased core and local skin temperatures on the local vascular response in calf skin under increasing orthostatic stress, the thigh was occluded at 20, 30, 50, 70, and 80 mmHg with a cuff in both the normothermic condition and the whole-body or local heating condition. Significant decreases in forearm SkBF during HUT were observed at an angle of 60 degrees during normothermia and at 30 degrees or more during heating. SkBF in the thigh and calf was decreased significantly by HUT at 15 degrees and above during normothermia, and there was no significant reduction of SkBF in these sites during HUT at the lower angles (15 degrees -45 degrees ) during whole-body heating. Significant decreases of calf SkBF were observed at cuff pressures of 20 mmHg and above during normothermia and of 30 mmHg and above during whole-body and local heating, respectively. These results suggest that SkBF in the lower extremities shows a marked reduction compared with the upper extremities during low orthostatic stress in normothermia, and the enhanced skin vasoconstrictor response in the lower extremities is diminished by both whole-body and local heat stress. PMID:16839449

  8. Transcriptionally and post-transcriptionally regulated microRNAs in heat stress response in barley

    PubMed Central

    Kruszka, Katarzyna; Pacak, Andrzej; Swida-Barteczka, Aleksandra; Nuc, Przemyslaw; Alaba, Sylwia; Wroblewska, Zuzanna; Karlowski, Wojciech; Jarmolowski, Artur; Szweykowska-Kulinska, Zofia

    2014-01-01

    Heat stress is one of the major abiotic factors that can induce severe plant damage, leading to a decrease in crop plant productivity. Despite barley being a cereal of great economic importance, few data are available concerning its thermotolerance mechanisms. In this work microRNAs (miRNAs) involved in heat stress response in barley were investigated. The level of selected barley mature miRNAs was examined by hybridization. Quantitative real-time PCR (RT-qPCR) was used to monitor the changes in the expression profiles of primary miRNA (pri-miRNA) precursors, as well as novel and conserved target genes during heat stress. The miRNA-mediated cleavage sites in the target transcripts were confirmed by degradome analysis and the 5’ RACE (rapid amplification of cDNA ends) approach. Four barley miRNAs (miR160a, 166a, 167h, and 5175a) were found which are heat stress up-regulated at the level of both mature miRNAs and precursor pri-miRNAs. Moreover, the splicing of introns hosting miR160a and miR5175a is also heat induced. The results demonstrate transcriptional and post-transcriptional regulation of heat-responsive miRNAs in barley. The observed induction of miRNA expression is correlated with the down-regulation of the expression level of their experimentally identified new and conservative target genes. PMID:25183744

  9. Specific microRNAs regulate heat stress responses in Caenorhabditis elegans.

    PubMed

    Nehammer, Camilla; Podolska, Agnieszka; Mackowiak, Sebastian D; Kagias, Konstantinos; Pocock, Roger

    2015-01-01

    The ability of animals to sense and respond to elevated temperature is essential for survival. Transcriptional control of the heat stress response has been much studied, whereas its posttranscriptional regulation by microRNAs (miRNAs) is not well understood. Here we analyzed the miRNA response to heat stress in Caenorhabditis elegans and show that a discrete subset of miRNAs is thermoregulated. Using in-depth phenotypic analyses of miRNA deletion mutant strains we reveal multiple developmental and post-developmental survival and behavioral functions for specific miRNAs during heat stress. We have identified additional functions for already known players (mir-71 and mir-239) as well as identifying mir-80 and the mir-229 mir-64-66 cluster as important regulators of the heat stress response in C. elegans. These findings uncover an additional layer of complexity to the regulation of stress signaling that enables animals to robustly respond to the changing environment. PMID:25746291

  10. Specific microRNAs Regulate Heat Stress Responses in Caenorhabditis elegans

    PubMed Central

    Nehammer, Camilla; Podolska, Agnieszka; Mackowiak, Sebastian D.; Kagias, Konstantinos; Pocock, Roger

    2015-01-01

    The ability of animals to sense and respond to elevated temperature is essential for survival. Transcriptional control of the heat stress response has been much studied, whereas its posttranscriptional regulation by microRNAs (miRNAs) is not well understood. Here we analyzed the miRNA response to heat stress in Caenorhabditis elegans and show that a discrete subset of miRNAs is thermoregulated. Using in-depth phenotypic analyses of miRNA deletion mutant strains we reveal multiple developmental and post-developmental survival and behavioral functions for specific miRNAs during heat stress. We have identified additional functions for already known players (mir-71 and mir-239) as well as identifying mir-80 and the mir-229 mir-64-66 cluster as important regulators of the heat stress response in C. elegans. These findings uncover an additional layer of complexity to the regulation of stress signaling that enables animals to robustly respond to the changing environment. PMID:25746291

  11. The Response to Heat Shock and Oxidative Stress in Saccharomyces cerevisiae

    PubMed Central

    Morano, Kevin A.; Grant, Chris M.; Moye-Rowley, W. Scott

    2012-01-01

    A common need for microbial cells is the ability to respond to potentially toxic environmental insults. Here we review the progress in understanding the response of the yeast Saccharomyces cerevisiae to two important environmental stresses: heat shock and oxidative stress. Both of these stresses are fundamental challenges that microbes of all types will experience. The study of these environmental stress responses in S. cerevisiae has illuminated many of the features now viewed as central to our understanding of eukaryotic cell biology. Transcriptional activation plays an important role in driving the multifaceted reaction to elevated temperature and levels of reactive oxygen species. Advances provided by the development of whole genome analyses have led to an appreciation of the global reorganization of gene expression and its integration between different stress regimens. While the precise nature of the signal eliciting the heat shock response remains elusive, recent progress in the understanding of induction of the oxidative stress response is summarized here. Although these stress conditions represent ancient challenges to S. cerevisiae and other microbes, much remains to be learned about the mechanisms dedicated to dealing with these environmental parameters. PMID:22209905

  12. Water availability as dominant control of heat stress responses in two contrasting tree species.

    PubMed

    Ruehr, Nadine K; Gast, Andreas; Weber, Christina; Daub, Baerbel; Arneth, Almut

    2016-02-01

    Heat waves that trigger severe droughts are predicted to increase globally; however, we lack an understanding of how trees respond to the combined change of extreme temperatures and water availability. Here, we studied the impacts of two consecutive heat waves as well as post-stress recovery in young Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) and Robinia pseudoacacia L. (black locust) growing under controlled conditions. Responses were compared under water supply close to the long-term average and under reduced irrigation to represent drought. Exposure to high temperatures (+10 °C above ambient) and vapour pressure deficit strongly affected the trees in terms of water relations, photosynthesis and growth. Douglas-fir used water resources conservatively, and transpiration decreased in response to mild soil water limitation. In black locust, heat stress led to pronounced tree water deficits (stem diameter shrinkage), accompanied by leaf shedding to alleviate stress on the hydraulic system. The importance of water availability during the heat waves became further apparent by a concurrent decline in photosynthesis and stomatal conductance with increasing leaf temperatures in both species, reaching the lowest rates in the heat-drought treatments. Stress severity determined both the speed and the amount of recovery. Upon release of stress, photosynthesis recovered rapidly in drought-treated black locust, while it remained below control rates in heat (t = -2.4, P < 0.05) and heat-drought stressed trees (t = 2.96, P < 0.05). In Douglas-fir, photosynthesis recovered quickly, while water-use efficiency increased in heat-drought trees because stomatal conductance remained reduced (t = -2.92, P < 0.05). Moreover, Douglas-fir was able to compensate for stem-growth reductions following heat (-40%) and heat-drought stress (-68%), but most likely at the expense of storage and other growth processes. Our results highlight the importance of studying heat waves alongside

  13. Characterization of a Novel DWD Protein that Participates in Heat Stress Response in Arabidopsis

    PubMed Central

    Kim, Soon-Hee; Lee, Joon-Hyun; Seo, Kyoung-In; Ryu, Boyeong; Sung, Yongju; Chung, Taijoon; Deng, Xing Wang; Lee, Jae-Hoon

    2014-01-01

    Cullin4-RING ubiquitin ligase (CRL4) is a family of multi-subunit E3 ligases. To investigate the possible involvement of CRL4 in heat stress response, we screened T-DNA insertion mutants of putative CRL4 substrate receptors that exhibited altered patterns in response to heat stress. One of the mutants exhibited heat stress tolerance and was named heat stress tolerant DWD1 (htd1). Introduction of HTD1 gene into htd1-1 led to recovery of heat sensitivity to the wild type level, confirming that the decrease of HTD1 transcripts resulted in heat tolerance. Therefore, HTD1 plays a negative role in thermotolerance in Arabidopsis. Additionally, HTD1 directly interacted with DDB1a in yeast two-hybrid assays and associated with DDB1b in vivo, supporting that it could be a part of a CRL4 complex. Various heat-inducible genes such as HSP14.7, HSP21, At2g03020 and WRKY28 were hyper-induced in htd1-1, indicating that HTD1 could function as a negative regulator for the expression of such genes and that these genes might contribute to thermotolerance of htd1-1, at least in part. HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo, even though the decrease of HTD1 did not affect the accumulation pattern of HSP90-1 in Arabidopsis. These findings indicate that a negative role of HTD1 in thermotolerance might be achieved through its association with HSP90-1, possibly by disturbing the action of HSP90-1, not by the degradation of HSP90-1. This study will serve as an important step toward understanding of the functional connection between CRL4-mediated processes and plant heat stress signaling. PMID:25358503

  14. Response of NBS encoding resistance genes linked to both heat and fungal stress in Brassica oleracea.

    PubMed

    Kim, Young-Wook; Jung, Hee-Jeong; Park, Jong-In; Hur, Yoonkang; Nou, Ill-Sup

    2015-01-01

    Environmental stresses, including both abiotic and biotic stresses, cause considerable yield loss in crops and can significantly affect their development. Under field conditions, crops are exposed to a variety of concurrent stresses. Among abiotic and biotic stresses, heat and Fusarium oxysporum, are the most important factors affecting development and yield productivity of Brassica oleracea. Genes encoding the nucleotide-binding site (NBS) motif are known to be related to responses to abiotic and biotic stresses in many plants. Hence, this study was conducted to characterize the NBS encoding genes obtained from transcriptome profiles of two cabbage genotypes with contrasting responses to heat stress, and to test expression levels of selected NBS- leucine reich repeat (LRR) genes in F. oxysporum infected plants. We selected 80 up-regulated genes from a total of 264 loci, among which 17 were confirmed to be complete and incomplete members of the TIR-NBS-LRR (TNL) class families, and another identified as an NFYA-HAP2 family member. Expression analysis using qRT-PCR revealed that eight genes showed significant responses to heat shock treatment and F. oxysporum infection. Additionally, in the commercial B. oleracea cultivars with resistance to F. oxysporum, the Bol007132, Bol016084, and Bol030522 genes showed dramatically higher expression in the F. oxysporum resistant line than in the intermediate and susceptible lines. The results of this study will facilitate the identification and the development of molecular markers based on multiple stress resistance genes related to heat and fungal stress under field conditions in B. oleracea. PMID:25461701

  15. Assessing climate change and heat stress responses in the Tarai region of Nepal.

    PubMed

    Pradhan, Bandana; Shrestha, Shailendra; Shrestha, Ranjana; Pradhanang, Sadhana; Kayastha, Birendra; Pradhan, Pushkar

    2013-01-01

    This paper intends to analyse responses of the working people to heat stress in Nepal's Tarai region. Here, the heat stress responses refer to the working environments- indoor and outdoor settings, prevailing diseases, and adaptive measures by the workers. Data were gathered from the sample households by using household survey, observation, and informal discussions. Environmental conditions in terms of heat exposure in the working areas have been measured with heat index, humidity index, and WBGT, based on the HOTHAPS approach. The findings are that: the average temperature during the peak hot months reached to over 39°C and the environmental conditions in the selected factories during the hot summer months were too hot to the workers to work continuously during the day, where there was inadequacy of facilities to combat against the hot. Males were more exposed than females to the heat due to heavy type of works in outdoor settings. Few workers found to have adapted coping measures such as shift in working time, wearing thin cotton clothes, etc but they were inadequate against the heat stress. More quantitative measurements of workers' health effects and productivity loss will be of interest for future works. PMID:23411760

  16. Functions of heat shock transcription factors involved in response to photooxidative stresses in Arabidopsis.

    PubMed

    Yabuta, Yukinori

    2016-07-01

    Because plants are continually exposed to various environmental stresses, they possess numerous transcription factors that regulate metabolism to adapt and acclimate to those conditions. To clarify the gene regulation systems activated in response to photooxidative stress, we isolated 76 high light and heat shock stress-inducible genes, including heat shock transcription factor (Hsf) A2 from Arabidopsis. Unlike yeast or animals, more than 20 genes encoding putative Hsfs are present in the genomes of higher plants, and they are categorized into three classes based on their structural characterization. However, the multiplicity of Hsfs in plants remains unknown. Furthermore, the individual functions of Hsfs are also largely unknown because of their genetic redundancy. Recently, the developments of T-DNA insertion knockout mutant lines and chimeric repressor gene-silencing technology have provided effective tools for exploring the individual functions of Hsfs. This review describes the current knowledge on the individual functions and activation mechanisms of Hsfs. PMID:27095030

  17. Tomato yellow leaf curl virus infection mitigates the heat stress response of plants grown at high temperatures

    PubMed Central

    Ghandi, Anfoka; Adi, Moshe; Lilia, Fridman; Linoy, Amrani; Or, Rotem; Mikhail, Kolot; Mouhammad, Zeidan; Henryk, Czosnek; Rena, Gorovits

    2016-01-01

    Cultured tomatoes are often exposed to a combination of extreme heat and infection with Tomato yellow leaf curl virus (TYLCV). This stress combination leads to intense disease symptoms and yield losses. The response of TYLCV-susceptible and resistant tomatoes to heat stress together with viral infection was compared. The plant heat-stress response was undermined in TYLCV infected plants. The decline correlated with the down-regulation of heat shock transcription factors (HSFs) HSFA2 and HSFB1, and consequently, of HSF-regulated genes Hsp17, Apx1, Apx2 and Hsp90. We proposed that the weakened heat stress response was due to the decreased capacity of HSFA2 to translocate into the nuclei of infected cells. All the six TYLCV proteins were able to interact with tomato HSFA2 in vitro, moreover, coat protein developed complexes with HSFA2 in nuclei. Capturing of HSFA2 by viral proteins could suppress the transcriptional activation of heat stress response genes. Application of both heat and TYLCV stresses was accompanied by the development of intracellular large protein aggregates containing TYLCV proteins and DNA. The maintenance of cellular chaperones in the aggregated state, even after recovery from heat stress, prevents the circulation of free soluble chaperones, causing an additional decrease in stress response efficiency. PMID:26792235

  18. Elevated local skin temperature impairs cutaneous vasoconstrictor responses to a simulated haemorrhagic challenge while heat stressed

    PubMed Central

    Pearson, J.; Lucas, R. A. I.; Crandall, C. G.

    2016-01-01

    During a simulated haemorrhagic challenge, syncopal symptoms develop sooner when individuals are hyperthermic relative to normothermic. This is due, in part, to a large displacement of blood to the cutaneous circulation during hyperthermia, coupled with inadequate cutaneous vasoconstriction during the hypotensive challenge. The influence of local skin temperature on these cutaneous vasoconstrictor responses is unclear. This project tested the hypothesis that local skin temperature modulates cutaneous vasoconstriction during simulated haemorrhage in hyperthermic humans. Eight healthy participants (four men and four women; 32 ± 7 years old; 75.2 ± 10.8 kg) underwent lower-body negative pressure to presyncope while heat stressed via a water-perfused suit sufficiently to increase core temperature by 1.2 ± 0.2°C. At forearm skin sites distal to the water-perfused suit, local skin temperature was either 35.2 ± 0.6 (mild heating) or 38.2 ± 0.2°C (moderate heating) throughout heat stress and lower-body negative pressure, and remained at these temperatures until presyncope. The reduction in cutaneous vascular conductance during the final 90 s of lower-body negative pressure, relative to heat-stress baseline, was greatest at the mildly heated site (−10 ± 15% reduction) relative to the moderately heated site (−2 ± 12%; P = 0.05 for the magnitude of the reduction in cutaneous vascular conductance between sites), because vasoconstriction at the moderately heated site was either absent or negligible. In hyperthermic individuals, the extent of cutaneous vasoconstriction during a simulated haemorrhage can be modulated by local skin temperature. In situations where skin temperature is at least 38°C, as is the case in soldiers operating in warm climatic conditions, a haemorrhagic insult is unlikely to be accompanied by cutaneous vasoconstriction. PMID:22903981

  19. Experience Modulates the Reproductive Response to Heat Stress in C. elegans via Multiple Physiological Processes

    PubMed Central

    Gouvêa, Devin Y.; Aprison, Erin Z.; Ruvinsky, Ilya

    2015-01-01

    Natural environments are considerably more variable than laboratory settings and often involve transient exposure to stressful conditions. To fully understand how organisms have evolved to respond to any given stress, prior experience must therefore be considered. We investigated the effects of individual and ancestral experience on C. elegans reproduction. We documented ways in which cultivation at 15°C or 25°C affects developmental time, lifetime fecundity, and reproductive performance after severe heat stress that exceeds the fertile range of the organism but is compatible with survival and future fecundity. We found that experience modulates multiple aspects of reproductive physiology, including the male and female germ lines and the interaction between them. These responses vary in their environmental sensitivity, suggesting the existence of complex mechanisms for coping with unpredictable and stressful environments. PMID:26713620

  20. Assessment of male anthropometric trends and the effects on simulated heat stress responses.

    PubMed

    Yokota, Miyo; Bathalon, Gaston P; Berglund, Larry G

    2008-09-01

    Assessing temporal changes in anthropometrics and body composition of US Army soldiers is important because these changes may affect fitness, performance, and safety. This study investigated differences in body dimensions (height, weight, percent body fat (%BF)) of US Army male soldiers by comparing 2004 and 1988 databases. Anthropometric somatotypes were identified and physiological responses of the different somatotypes to simulated heat stress (35 degrees C/50%rh, approximately 550 W work rate, carrying 12 kg load including battle dress uniform and body armor, rest for 30 min and walk for 70 min) using a thermal regulatory model were evaluated. A significant increase in body weight (2.4 kg) was observed between the 2004 and 1988 data (P < 0.05, after Bonferroni correction). However, changes in height and circumference measurements for %BF were insignificant, with the magnitude of the changes not exceeding inter-observer errors. Multivariate analyses demonstrated that anthropometric distributions did not differ between the two databases and identified five primary somatotypes: "tall-fat", "tall-lean", "average", "short-lean", and "short-fat." Within each database, anthropometric values differed among the somatotypes. However, simulated physiological responses to heat stress in each somatotype were similar in the 2004 and 1988 populations. In conclusion, an increase in body weight was the primary change observed in this sample of US Army male soldiers. Temporal changes in somatotypes of soldiers over a 16-year period had minimal impact on simulated physiological response to heat stress using a thermal regulatory model. PMID:18196265

  1. Relationship between Aflatoxin Contamination and Physiological Responses of Corn Plants under Drought and Heat Stress

    PubMed Central

    Kebede, Hirut; Abbas, Hamed K.; Fisher, Daniel K.; Bellaloui, Nacer

    2012-01-01

    Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54) at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination. PMID:23202322

  2. Long-term heat stress induces the inflammatory response in dairy cows revealed by plasma proteome analysis.

    PubMed

    Min, Li; Zheng, Nan; Zhao, Shengguo; Cheng, Jianbo; Yang, Yongxin; Zhang, Yangdong; Yang, Hongjian; Wang, Jiaqi

    2016-03-01

    In this work we employed a comparative proteomic approach to evaluate seasonal heat stress and investigate proteomic alterations in plasma of dairy cows. Twelve lactating Holstein dairy cows were used and the treatments were: heat stress (n = 6) in hot summer (at the beginning of the moderate heat stress) and no heat stress (n = 6) in spring natural ambient environment, respectively. Subsequently, heat stress treatment lasted 23 days (at the end of the moderate heat stress) to investigate the alterations of plasma proteins, which might be employed as long-term moderate heat stress response in dairy cows. Changes in plasma proteins were analyzed by two-dimensional electrophoresis (2-DE) combined with mass spectrometry. Analysis of the properties of the identified proteins revealed that the alterations of plasma proteins were related to inflammation in long-term moderate heat stress. Furthermore, the increase in plasma tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) directly demonstrated that long-term moderate heat stress caused an inflammatory response in dairy cows. PMID:26851364

  3. The Heat Stress Response and Diabetes: More Room for Mitochondrial Implication.

    PubMed

    Miova, Biljana; Dimitrovska, Maja; Dinevska-Kjovkarovska, Suzana; Esplugues, Juan V; Apostolova, Nadezda

    2016-01-01

    Heat preconditioning is a rapid cellular adaptive mechanism shared by many cells/ organs / organisms that results in synthesis and accumulation of heat shock proteins (HSPs), which are responsible for increased tolerance and survival of animals during and after heat stress (HS). HSPs function as molecular chaperones by restoring cellular homeostasis and promoting cell survival, and their major functions include protection of cells from injury by preventing protein damage and aggregation. Abundant evidence points to the ability of one kind of stress caused by external factors that induce primary adaptations in the organism to provide protection against additional stress of the same or another type, a phenomenon known as cross-tolerance. Diabetes mellitus (DM) is one of the diseases which have been associated with increased tissue sensitivity and vulnerability due to incorrect protein folding. Thus, HSPs may play an important role in minimizing the protein damage that can occur under the stressful conditions created by the disease. By increasing HSP production, heat preconditioning may be a promising therapy for patients with lifestylerelated diseases such as hypercholesterolemia, hypertension, DM and obesity. Also, pancreatic β-cells exposed to acute HS activate defence mechanisms which include HSP synthesis and are less sensitive to the effects of cytotoxic agents such as NO, oxygen radicals and β-cytotoxic diabetogenic agents, such as streptozotocin (STZ). Mitochondrial dysfunction and mitochondria-specific cell stress are associated and can even be a primary abnormality caused by DMinduced hyperglycaemia and oxidative stress. There are an increasing number of genetic and/or pharmacological modulations of HSPs that have revealed the connection between HSPs, mitochondria and diabetes. HSPs may affect mitochondrial function in multiple ways, but the influence on skeletal muscle and adipose tissue, as well as on the pancreas, has attracted most interest as a key

  4. Heat Shock Factor Genes of Tall Fescue and Perennial Ryegrass in Response to Temperature Stress by RNA-Seq Analysis

    PubMed Central

    Wang, Yan; Dai, Ya; Tao, Xiang; Wang, Jia-Zhen; Cheng, Hai-Yang; Yang, Hong; Ma, Xin-Rong

    2016-01-01

    Heat shock factors (Hsfs) are important regulators of stress-response in plants. However, our understanding of Hsf genes and their responses to temperature stresses in two Pooideae cool-season grasses, Festuca arundinacea, and Lolium perenne, is limited. Here we conducted comparative transcriptome analyses of plant leaves exposed to heat or cold stress for 10 h. Approximately, 30% and 25% of the genes expressed in the two species showed significant changes under heat and cold stress, respectively, including subsets of Hsfs and their target genes. We uncovered 74 Hsfs in F. arundinacea and 52 Hsfs in L. perenne, and categorized these genes into three subfamilies, HsfA, HsfB, and HsfC based on protein sequence homology to known Hsf members in model organisms. The Hsfs showed a strong response to heat and/or cold stress. The expression of HsfAs was elevated under heat stress, especially in class HsfA2, which exhibited the most dramatic responses. HsfBs were upregulated by the both temperature conditions, and HsfCs mainly showed an increase in expression under cold stress. The target genes of Hsfs, such as heat shock protein (HSP), ascorbate peroxidase (APX), inositol-3-phosphate synthase (IPS), and galactinol synthase (GOLS1), showed strong and unique responses to different stressors. We comprehensively detected Hsfs and their target genes in F. arundinacea and L. perenne, providing a foundation for future gene function studies and genetic engineering to improve stress tolerance in grasses and other crops. PMID:26793208

  5. Review of comparative responses of men and women to heat stress

    SciTech Connect

    Kenney, W.L.

    1985-01-01

    Most of their present knowledge regarding human responses to thermal stress is primarily a result of research conducted on male subjects. Recently, as women have moved into the industrial workplace and forefront of athletic activity, attention has turned to comparative responses of men and women. Very limited research on preadolescent children suggests no physiological thermoregulatory sex differences except for a slightly higher sweat rate in lean boys as compared to lean girls of a similar age. Boys also tended to be more tolerant of higher temperatures. Current beliefs regarding men and women are: (1) women, as a population, are less tolerant to a given imposed heat stress however, if cardiovascular fitness level, body size, and acclimation state are standardized, the differences tend to disappear; (2) women have a lower sweat rate than men of equal fitness, size, and acclimation which is disadvantageous in hot-dry environments, but advantageous in hot-wet environments; and (3) menstrual cycle effects are minimal. It is concluded that aerobic capacity, surface area-to-mass ratio, and state of acclimation are more important than sex in determining physiological responses to heat stress.

  6. Thermotolerant yeasts selected by adaptive evolution express heat stress response at 30 °C

    PubMed Central

    Caspeta, Luis; Chen, Yun; Nielsen, Jens

    2016-01-01

    Exposure to long-term environmental changes across >100s of generations results in adapted phenotypes, but little is known about how metabolic and transcriptional responses are optimized in these processes. Here, we show that thermotolerant yeast strains selected by adaptive laboratory evolution to grow at increased temperature, activated a constitutive heat stress response when grown at the optimal ancestral temperature, and that this is associated with a reduced growth rate. This preventive response was perfected by additional transcriptional changes activated when the cultivation temperature is increased. Remarkably, the sum of global transcriptional changes activated in the thermotolerant strains when transferred from the optimal to the high temperature, corresponded, in magnitude and direction, to the global changes observed in the ancestral strain exposed to the same transition. This demonstrates robustness of the yeast transcriptional program when exposed to heat, and that the thermotolerant strains streamlined their path to rapidly and optimally reach post-stress transcriptional and metabolic levels. Thus, long-term adaptation to heat improved yeasts ability to rapidly adapt to increased temperatures, but this also causes a trade-off in the growth rate at the optimal ancestral temperature. PMID:27229477

  7. Thermotolerant yeasts selected by adaptive evolution express heat stress response at 30 °C.

    PubMed

    Caspeta, Luis; Chen, Yun; Nielsen, Jens

    2016-01-01

    Exposure to long-term environmental changes across >100s of generations results in adapted phenotypes, but little is known about how metabolic and transcriptional responses are optimized in these processes. Here, we show that thermotolerant yeast strains selected by adaptive laboratory evolution to grow at increased temperature, activated a constitutive heat stress response when grown at the optimal ancestral temperature, and that this is associated with a reduced growth rate. This preventive response was perfected by additional transcriptional changes activated when the cultivation temperature is increased. Remarkably, the sum of global transcriptional changes activated in the thermotolerant strains when transferred from the optimal to the high temperature, corresponded, in magnitude and direction, to the global changes observed in the ancestral strain exposed to the same transition. This demonstrates robustness of the yeast transcriptional program when exposed to heat, and that the thermotolerant strains streamlined their path to rapidly and optimally reach post-stress transcriptional and metabolic levels. Thus, long-term adaptation to heat improved yeasts ability to rapidly adapt to increased temperatures, but this also causes a trade-off in the growth rate at the optimal ancestral temperature. PMID:27229477

  8. Inactivation of GABAA receptor is related to heat shock stress response in organism model Caenorhabditis elegans.

    PubMed

    Camargo, Gabriela; Elizalde, Alejandro; Trujillo, Xochitl; Montoya-Pérez, Rocío; Mendoza-Magaña, María Luisa; Hernandez-Chavez, Abel; Hernandez, Leonardo

    2016-09-01

    The mechanisms underlying oxidative stress (OS) resistance are not completely clear. Caenorhabditis elegans (C. elegans) is a good organism model to study OS because it displays stress responses similar to those in mammals. Among these mechanisms, the insulin/IGF-1 signaling (IIS) pathway is thought to affect GABAergic neurotransmission. The aim of this study was to determine the influence of heat shock stress (HS) on GABAergic activity in C. elegans. For this purpose, we tested the effect of exposure to picrotoxin (PTX), gamma-aminobutyric acid (GABA), hydrogen peroxide, and HS on the occurrence of a shrinking response (SR) after nose touch stimulus in N2 (WT) worms. Moreover, the effect of HS on the expression of UNC-49 (GABAA receptor ortholog) in the EG1653 strain and the effect of GABA and PTX exposure on HSP-16.2 expression in the TJ375 strain were analyzed. PTX 1 mM- or H2O2 0.7 mM-exposed worms displayed a SR in about 80 % of trials. GABA exposure did not cause a SR. HS prompted the occurrence of a SR as did PTX 1 mM or H2O2 0.7 mM exposure. In addition, HS increased UNC-49 expression, and PTX augmented HSP-16.2 expression. Thus, the results of the present study suggest that oxidative stress, through either H2O2 exposure or application of heat shock, inactivates the GABAergic system, which subsequently would affect the oxidative stress response, perhaps by enhancing the activity of transcription factors DAF-16 and HSF-1, both regulated by the IIS pathway and related to hsp-16.2 expression. PMID:27230213

  9. The impact of heat stress targeting on the hormonal and transcriptomic response in Arabidopsis.

    PubMed

    Dobrá, Jana; Černý, Martin; Štorchová, Helena; Dobrev, Petre; Skalák, Jan; Jedelský, Petr L; Lukšanová, Hana; Gaudinová, Alena; Pešek, Bedřich; Malbeck, Jiří; Vanek, Tomas; Brzobohatý, Břetislav; Vanková, Radomíra

    2015-02-01

    Targeting of the heat stress (HS, 40°C) to shoots, roots or whole plants substantially affects Arabidopsis physiological responses. Effective stress targeting was proved by determination of the expression of HS markers, HsfA2 and HSA32, which were quickly stimulated in the targeted organ(s), but remained low in non-stressed tissues for at least 2h. When shoots or whole plants were subjected to HS, a transient decrease in abscisic acid, accompanied by a small increase in active cytokinin levels, was observed in leaves, consistent with stimulation of transpiration, the main cooling mechanism in leaves. HS application targeted to part of plant resulted in a rapid stimulation of expression of components of cytokinin signaling pathway (especially of receptor genes) in the non-exposed tissues, which indicated fast inter-organ communication. Under all HS treatments, shoot apices responded by transient elevation of active cytokinin contents and stimulation of transcription of genes involved in photosynthesis and carbohydrate metabolism. Duration of this stimulation was negatively correlated with stress strength. The impact of targeted HS on the expression of 63 selected genes, including those coding regulatory 14-3-3 proteins, was compared. Stimulation of GRF9 (GRF14μ) in stressed organs after 2-6h may be associated with plant stress adaptation. PMID:25575991

  10. Heat stroke activates a stress-induced cytokine response in skeletal muscle.

    PubMed

    Welc, Steven S; Clanton, Thomas L; Dineen, Shauna M; Leon, Lisa R

    2013-10-15

    Heat stroke (HS) induces a rapid elevation in a number of circulating cytokines. This is often attributed to the stimulatory effects of endotoxin, released from damaged intestine, on immune cells. However, parenchymal cells also produce cytokines, and skeletal muscle, comprising a large proportion of body mass, is thought to participate. We tested the hypothesis that skeletal muscle exhibits a cytokine response to HS that parallels the systemic response in conscious mice heated to a core temperature of 42.4°C (TcMax). Diaphragm and hindlimb muscles showed a rapid rise in interleukin-6 (IL-6) and interleuin-10 (IL-10) mRNA and transient inhibition of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) throughout early recovery, a pattern that parallels changes in circulating cytokines. IL-6 protein was transiently elevated in both muscles at ∼32 min after reaching TcMax. Other responses observed included an upregulation of toll-like receptor-4 (TLR-4) and heat shock protein-72 (HSP-72) mRNA but no change in TLR-2 or HSP25 mRNA. Furthermore, c-jun and c-fos mRNA increased. Together, c-jun/c-fos form the activator protein-1 (AP-1) transcription factor, critical for stress-induced regulation of IL-6. Interestingly, a second "late-phase" (24 h) cytokine response, with increases in IL-6, IL-10, IL-1β, and TNF-α protein, were observed in hindlimb but not diaphragm muscle. These results demonstrate that skeletal muscle responds to HS with a distinct "stress-induced immune response," characterized by an early upregulation of IL-6, IL-10, and TLR-4 and suppression of IL-1β and TNF-α mRNA, a pattern discrete from classic innate immune cytokine responses. PMID:23928112

  11. ROLE OF ENVIRONMENTAL HEAT AND COLD STRESS ON THE PHYSIOLOGICAL RESPONSE TO ORGANOPHOSPHATES AND OTHER TOXICANTS.

    EPA Science Inventory

    Most toxicological and pharmacological studies are performed in laboratory rodents maintained under comfortable environmental conditions. However, exposure to toxicants as well as some drugs can occur under stressful conditions during rest or while exercising. Heat stress can exa...

  12. Proteome profiling of heat, oxidative, and salt stress responses in Thermococcus kodakarensis KOD1

    PubMed Central

    Jia, Baolei; Liu, Jinliang; Van Duyet, Le; Sun, Ying; Xuan, Yuan H.; Cheong, Gang-Won

    2015-01-01

    The thermophilic species, Thermococcus kodakarensis KOD1, a model microorganism for studying hyperthermophiles, has adapted to optimal growth under conditions of high temperature and salinity. However, the environmental conditions for the strain are not always stable, and this strain might face different stresses. In the present study, we compared the proteome response of T. kodakarensis to heat, oxidative, and salt stresses using two-dimensional electrophoresis, and protein spots were identified through MALDI-TOF/MS. Fifty-nine, forty-two, and twenty-nine spots were induced under heat, oxidative, and salt stresses, respectively. Among the up-regulated proteins, four proteins (a hypothetical protein, pyridoxal biosynthesis lyase, peroxiredoxin, and protein disulphide oxidoreductase) were associated with all three stresses. Gene ontology analysis showed that these proteins were primarily involved metabolic and cellular processes. The KEGG pathway analysis suggested that the main metabolic pathways involving these enzymes were related to carbohydrate metabolism, secondary metabolite synthesis, and amino acid biosynthesis. These data might enhance our understanding of the functions and molecular mechanisms of thermophilic Archaea for survival and adaptation in extreme environments. PMID:26150806

  13. Wheat cultivars differing in heat tolerance show a differential response to oxidative stress during monocarpic senescence under high temperature stress.

    PubMed

    Khanna-Chopra, Renu; Chauhan, Shakti

    2015-09-01

    Wheat crop may experience heat stress during post-anthesis phase associated with oxidative stress, enhanced senescence, and reduced productivity. Stay green is a desirable character for the selection for heat tolerance in wheat. In the present study, antioxidant metabolism was studied under post-anthesis heat stress in field during monocarpic senescence by comparing two wheat genotypes, namely Hindi62 (heat tolerant and delayed senescent) and PBW343 (heat susceptible and early senescent). Hindi62 exhibited lesser oxidative stress, membrane damage, and coordinated antioxidant defense as compared to PBW343 under heat stress during post-anthesis stage. Higher activity of SOD, CAT, APX, GR, and MDHAR under heat stress contributed towards delayed senescence in Hindi62 compared to PBW343. GSH/GSSG ratio was also maintained at higher level in Hindi62 under heat stress compared to PBW343 during senescence. Hence, the present study clearly shows that upregulated level of the total antioxidant capacity during grain development contributed towards delayed senescence and heat tolerance in Hindi62 compared to the heat-susceptible PBW343. PMID:25586109

  14. Oxidative, heat and anthelminthic stress responses in four species of Trichinella: comparative study.

    PubMed

    Martinez, Javier; Perez-Serrano, Jorge; Bernadina, W E; Rodriguez-Caabeiro, Filomena

    2002-12-01

    The aim of this study was to compare levels of stress proteins in four Trichinella species when exposed to different stressors. Heat shock protein (HSP) 60, 70 and 90 responses were evaluated in infective larvae (L(1)) of four classic Trichinella species following exposure to oxidative, anthelminthic and thermal stress. Larvae of T. nativa, T nelsoni, T. pseudospiralis and T. spiralis were exposed to peroxide shock (0.2%, 1%, or 2% H(2)O(2)for 2h), high temperatures (40 degrees C or 45 degrees C for 2h), or 0.1 microg/ml of the benzimidazole anthelminthics: mebendazole (MBZ), albendazole (ALB) or thiabendazole (TBZ) for 4h. Following exposures, the L(1) were tested for induced morphological changes. Those observed were: (i) no change (in all species exposed to 40 degrees C) (ii) aberrant forms (in all species exposed to anthelminthics, in T. nativa, T. nelsoni and T. spiralis exposed to 45 degrees C, and in T. spiralis and T. nelsoni exposed to 0.2% H(2)O(2)) and (iii) severe degradation or death (in T. nativa and T. pseudospiralis exposed to 0.2% H(2)O(2), and in all species at 1% and 2% H(2)O(2)). In Western blot analyses, L(1) proteins were probed with monoclonal antibodies (mAbs) specific for the three HSPs. Greater changes in HSP levels occurred following H(2)O(2) exposure than with other stresses in all Trichinella species, while accumulation of a 50 kDa HSP was only observed in T. spiralis and T. pseudospiralis. Anthelminthic stress only caused decreased HSP levels in T. nativa. Thermal stress caused no significant changes in the HSP response of any species. It is suggested that other stress proteins (e.g., glucose-regulated proteins) may be involved in adaptation to thermal stress. PMID:12410594

  15. Ebola Response: Modeling the Risk of Heat Stress from Personal Protective Clothing

    PubMed Central

    Potter, Adam W.; Gonzalez, Julio A.; Xu, Xiaojiang

    2015-01-01

    Introduction A significant number of healthcare workers have responded to aid in the relief and containment of the 2013 Ebola virus disease (EVD) outbreak in West Africa. Healthcare workers are required to wear personal protective clothing (PPC) to impede the transmission of the virus; however, the impermeable design and the hot humid environment lead to risk of heat stress. Objective Provide healthcare workers quantitative modeling and analysis to aid in the prevention of heat stress while wearing PPC in West Africa. Methods A sweating thermal manikin was used to measure the thermal (Rct) and evaporative resistance (Ret) of the five currently used levels of PPC for healthcare workers in the West Africa EVD response. Mathematical methods of predicting the rise in core body temperature (Tc) in response to clothing, activity, and environment was used to simulate different responses to PPC levels, individual body sizes, and two hot humid conditions: morning/evening (air temperature: 25°C, relative humidity: 40%, mean radiant temperature: 35°C, wind velocity: 1 m/s) and mid-day (30°C, 60%, 70°C, 1 m/s). Results Nearly still air (0.4 m/s) measures of Rct ranged from 0.18 to 0.26 m2 K/W and Ret ranged from 25.53 to 340.26 m2 Pa/W. Conclusion Biophysical assessments and modeling in this study provide quantitative guidance for prevention of heat stress of healthcare workers wearing PPC responding to the EVD outbreak in West Africa. PMID:26575389

  16. The hypophagic response to heat stress is not mediated by GPR109A or peripheral β-OH butyrate.

    PubMed

    Hepler, Chelsea; Foy, Caroline E; Higgins, Mark R; Renquist, Benjamin J

    2016-05-15

    Rising temperatures resulting from climate change will increase the incidence of heat stress, negatively impacting the labor force and food animal production. Heat stress elevates circulating β-OH butyrate, which induces vasodilation through GPR109a. Interestingly, both heat stress and intraperitoneal β-OH butyrate administration induce hypophagia. Thus, we aimed to investigate the role of β-OH butyrate in heat stress hypophagia in mice. We found that niacin, a β-OH butyrate mimetic that cannot be oxidized to generate ATP, also reduces food intake. Interestingly, the depression in food intake as a result of 8-h intraperitoneal niacin or 48-h heat exposure did not result from changes in hypothalamic expression of orexigenic or anorexigenic signals (AgRP, NPY, or POMC). Genetically eliminating GPR109a expression did not prevent the hypophagic response to heat exposure, intraperitoneal β-OH butyrate (5.7 mmol/kg), or niacin (0.8 mmol/kg). Hepatic vagotomy eliminated the hypophagic response to β-OH butyrate and niacin but did not affect the hypophagic response to heat exposure. We subsequently hypothesized that the hypophagic response to heat stress may depend on direct effects of β-OH butyrate at the central nervous system: β-OH butyrate induced hormonal changes (hyperinsulinemia, hypercorticosteronemia, and hyperleptinemia), or gene expression changes. To test these possibilities, we blocked expression of hepatic hydroxyl methyl glutaryl CoA synthase II (HMGCS2) to prevent hepatic β-OH butyrate synthesis. Mice that lack HMGCS2 maintain a hypophagic response to heat stress. Herein, we establish that the hypophagia of heat stress is independent of GPR109a, the hepatic vagus afferent nerve, and hepatic ketone body synthesis. PMID:26936786

  17. Arabidopsis non-specific phospholipase C1: characterization and its involvement in response to heat stress.

    PubMed

    Krčková, Zuzana; Brouzdová, Jitka; Daněk, Michal; Kocourková, Daniela; Rainteau, Dominique; Ruelland, Eric; Valentová, Olga; Pejchar, Přemysl; Martinec, Jan

    2015-01-01

    The Arabidopsis non-specific phospholipase C (NPC) protein family is encoded by the genes NPC1 - NPC6. It has been shown that NPC4 and NPC5 possess phospholipase C activity; NPC3 has lysophosphatidic acid phosphatase activity. NPC3, 4 and 5 play roles in the responses to hormones and abiotic stresses. NPC1, 2 and 6 has not been studied functionally yet. We found that Arabidopsis NPC1 expressed in Escherichia coli possesses phospholipase C activity in vitro. This protein was able to hydrolyse phosphatidylcholine to diacylglycerol. NPC1-green fluorescent protein was localized to secretory pathway compartments in Arabidopsis roots. In the knock out T-DNA insertion line NPC1 (npc1) basal thermotolerance was impaired compared with wild-type (WT); npc1 exhibited significant decreases in survival rate and chlorophyll content at the seventh day after heat stress (HS). Conversely, plants overexpressing NPC1 (NPC1-OE) were more resistant to HS compared with WT. These findings suggest that NPC1 is involved in the plant response to heat. PMID:26581502

  18. Arabidopsis non-specific phospholipase C1: characterization and its involvement in response to heat stress

    PubMed Central

    Krčková, Zuzana; Brouzdová, Jitka; Daněk, Michal; Kocourková, Daniela; Rainteau, Dominique; Ruelland, Eric; Valentová, Olga; Pejchar, Přemysl; Martinec, Jan

    2015-01-01

    The Arabidopsis non-specific phospholipase C1 (NPC) protein family is encoded by the genes NPC1 – NPC6. It has been shown that NPC4 and NPC5 possess phospholipase C activity; NPC3 has lysophosphatidic acid phosphatase activity. NPC3, 4 and 5 play roles in the responses to hormones and abiotic stresses. NPC1, 2 and 6 has not been studied functionally yet. We found that Arabidopsis NPC1 expressed in Escherichia coli possesses phospholipase C activity in vitro. This protein was able to hydrolyse phosphatidylcholine to diacylglycerol. NPC1-green fluorescent protein was localized to secretory pathway compartments in Arabidopsis roots. In the knock out T-DNA insertion line NPC1 (npc1) basal thermotolerance was impaired compared with wild-type (WT); npc1 exhibited significant decreases in survival rate and chlorophyll content at the seventh day after heat stress (HS). Conversely, plants overexpressing NPC1 (NPC1-OE) were more resistant to HS compared with WT. These findings suggest that NPC1 is involved in the plant response to heat. PMID:26581502

  19. Oligo-microarray analysis and identification of stress-immune response genes from manila clam (Ruditapes philippinarum) exposure to heat and cold stresses.

    PubMed

    Menike, Udeni; Lee, Youngdeuk; Oh, Chulhong; Wickramaarachchi, W D N; Premachandra, H K A; Park, Se Chang; Lee, Jehee; De Zoysa, Mahanama

    2014-10-01

    Thermal stress regulates the complex system of gene expression and downstream biochemical and physiological responses in aquatic species. To identify genes involved in heat stress responses in manila clam (Ruditapes philippinarum), microarray analysis was conducted using clam transcriptome generated by pyrosequencing of cDNA library. Manila clams were exposed to heat (30 ± 1 °C) and cold (4 ± 1 °C) stresses and compared with control animals (18 ± 1 °C). Heat stressed animals have changed greater number of transcripts (8,306) than cold stress (7,573). Results of both heat and cold exposure has shown that over 2-fold up-regulated or down regulated (>2-or <2-fold) transcripts were higher at 24 h than at 6 h. It suggests that silent and constitutive express genes can activate at critical stage of thermal stress which could be between 6 and 24 h post stresses. We identified wide range of stress-immune response genes such as transcription factors, heat shock proteins, antioxidant and detoxification enzymes, inflammatory and apoptosis related genes, cell adhesion molecules, cytokines, and IFN regulatory proteins. Histological results revealed that non-specific cellular alterations such as lesions, hypertrophy, and necrosis in stressed gills could be due to decrease of gas exchange rate which may cause hypoxia. PMID:25024045

  20. Physiological and Metabolic Changes of Purslane (Portulaca oleracea L.) in Response to Drought, Heat, and Combined Stresses

    PubMed Central

    Jin, Rui; Wang, Yanping; Liu, Ruijie; Gou, Junbo; Chan, Zhulong

    2016-01-01

    Purslane (Portulaca oleracea L.) is a fleshy herbaceous plant. So far, little information is available on the response of this plant to combined drought and heat stress. In this study, changes in physiological and metabolic levels were characterized after treatments with drought, heat and combined stresses. Both individual and combined stress treatments increased malondialdehyde (MDA), electrolyte leakage (EL), O2•− and activities of superoxide dismutase (SOD), peroxidase (POD), while declined chlorophyll content. No significant differences were found between control and treatments in leaf water content (LWC) and catalase (CAT) activity. Additionally, 37 metabolic compounds were detected in purslane. Through pathway analysis, 17 metabolites were directly involved in the glycolysis metabolic pathway. The present study indicated that combined drought and heat stress caused more serious damage in purslane than individual stress. To survive, purslane has a high capability to cope with environmental stress conditions through activation of physiological and metabolic pathways. PMID:26779204

  1. Proteomic changes of the porcine small intestine in response to chronic heat stress

    PubMed Central

    Cui, Yanjun; Gu, Xianhong

    2015-01-01

    Acute heat stress (HS) negatively affects intestinal integrity and barrier function. In contrast, chronic mild HS poses a distinct challenge to animals. Therefore, this study integrates biochemical, histological and proteomic approaches to investigate the effects of chronic HS on the intestine in finishing pigs. Castrated male crossbreeds (79.00±1.50 kg BW) were subjected to either thermal neutral (TN, 21 °C; 55%±5% humidity; n=8) or HS conditions (30 °C; 55%±5% humidity; n=8) for 3 weeks. The pigs were sacrificed after 3 weeks of high environmental exposure and the plasma hormones, the intestinal morphology, integrity, and protein profiles of the jejunum mucosa were determined. Chronic HS reduced the free triiodothyronine (FT3) and GH levels. HS damaged intestinal morphology, increased plasma d-lactate concentrations and decreased alkaline phosphatase activity of intestinal mucosa. Proteome analysis of the jejunum mucosa was conducted by 2D gel electrophoresis and mass spectrometry. Fifty-three intestinal proteins were found to be differentially abundant, 18 of which were related to cell structure and motility, and their changes in abundance could comprise intestinal integrity and function. The down-regulation of proteins involved in tricarboxylic acid cycle (TCA cycle), electron transport chain (ETC), and oxidative phosphorylation suggested that chronic HS impaired energy metabolism and thus induced oxidative stress. Moreover, the changes of ten proteins in abundance related to stress response and defense indicated pigs mediated long-term heat exposure and counteracted its negative effects of heat exposure. These findings have important implications for understanding the effect of chronic HS on intestines. PMID:26416815

  2. Proteomic changes of the porcine small intestine in response to chronic heat stress.

    PubMed

    Cui, Yanjun; Gu, Xianhong

    2015-12-01

    Acute heat stress (HS) negatively affects intestinal integrity and barrier function. In contrast, chronic mild HS poses a distinct challenge to animals. Therefore, this study integrates biochemical, histological and proteomic approaches to investigate the effects of chronic HS on the intestine in finishing pigs. Castrated male crossbreeds (79.00 ± 1.50 kg BW) were subjected to either thermal neutral (TN, 21 °C; 55% ± 5% humidity; n=8) or HS conditions (30 °C; 55% ± 5% humidity; n=8) for 3 weeks. The pigs were sacrificed after 3 weeks of high environmental exposure and the plasma hormones, the intestinal morphology, integrity, and protein profiles of the jejunum mucosa were determined. Chronic HS reduced the free triiodothyronine (FT3) and GH levels. HS damaged intestinal morphology, increased plasma d-lactate concentrations and decreased alkaline phosphatase activity of intestinal mucosa. Proteome analysis of the jejunum mucosa was conducted by 2D gel electrophoresis and mass spectrometry. Fifty-three intestinal proteins were found to be differentially abundant, 18 of which were related to cell structure and motility, and their changes in abundance could comprise intestinal integrity and function. The down-regulation of proteins involved in tricarboxylic acid cycle (TCA cycle), electron transport chain (ETC), and oxidative phosphorylation suggested that chronic HS impaired energy metabolism and thus induced oxidative stress. Moreover, the changes of ten proteins in abundance related to stress response and defense indicated pigs mediated long-term heat exposure and counteracted its negative effects of heat exposure. These findings have important implications for understanding the effect of chronic HS on intestines. PMID:26416815

  3. Characterization of physiological response and identification of associated genes under heat stress in rice seedlings.

    PubMed

    Xue, Da-Wei; Jiang, Hua; Hu, Jiang; Zhang, Xiao-Qin; Guo, Long-Biao; Zeng, Da-Li; Dong, Guo-Jun; Sun, Guo-Chang; Qian, Qian

    2012-12-01

    Global warming, which is caused by greenhouse gas emissions, makes food crops more vulnerable to heat stress. Understanding the heat stress-related mechanisms in crops and classifying heat stress-related genes can increase our knowledge in heat-resistant molecular biology and propel developments in molecular design breeding, which can help rice cope with unfavorable temperatures. In this study, we carried out a physiological analysis of rice plants after heat stress. The results show a dramatic increase in malondialdehyde contents and SOD activities. We successfully isolated 11 heat-related rice genes with known function annotation through DNSH, which is an improved SSH method for screening long cDNA fragments. The reanalysis of microarray data from public database revealed that all these genes displayed various expression patterns after heat stress, drought, cold and salt. Quantitative real-time reverse transcription PCR was also performed to validate the expression of these genes after heat stress. The expressions in 10 genes were all significantly changed except for contig 77, which is a CBL-interacting protein kinase. Several reports have been published about the members of the same gene family. PMID:23037947

  4. Cognitive and perceptual responses during passive heat stress in younger and older adults.

    PubMed

    Schlader, Zachary J; Gagnon, Daniel; Adams, Amy; Rivas, Eric; Cullum, C Munro; Crandall, Craig G

    2015-05-15

    We tested the hypothesis that attention, memory, and executive function are impaired to a greater extent in passively heat-stressed older adults than in passively heat-stressed younger adults. In a randomized, crossover design, 15 older (age: 69 ± 5 yr) and 14 younger (age: 30 ± 4 yr) healthy subjects underwent passive heat stress and time control trials. Cognitive tests (outcomes: accuracy and reaction time) from the CANTAB battery evaluated attention [rapid visual processing (RVP), choice reaction time (CRT)], memory [spatial span (SSP), pattern recognition memory (PRM)], and executive function [one touch stockings of Cambridge (OTS)]. Testing was undertaken on two occasions during each trial, at baseline and after internal temperature had increased by 1.0 ± 0.2°C or after a time control period. For tests that measured attention, reaction time during RVP and CRT was slower (P ≤ 0.01) in the older group. During heat stress, RVP reaction time improved (P < 0.01) in both groups. Heat stress had no effect (P ≥ 0.09) on RVP or CRT accuracy in either group. For tests that measured memory, accuracy on SSP and PRM was lower (P < 0.01) in the older group, but there was no effect of heat stress (P ≥ 0.14). For tests that measured executive function, overall, accuracy on OTS was lower, and reaction time was slower in the older group (P ≤ 0.05). Reaction time generally improved during heat stress, but there was no effect of heat stress on accuracy in either group. These data indicate that moderate increases in body temperature during passive heat stress do not differentially compromise cognitive function in younger and older adults. PMID:25786484

  5. Cognitive and perceptual responses during passive heat stress in younger and older adults

    PubMed Central

    Schlader, Zachary J.; Gagnon, Daniel; Adams, Amy; Rivas, Eric; Cullum, C. Munro

    2015-01-01

    We tested the hypothesis that attention, memory, and executive function are impaired to a greater extent in passively heat-stressed older adults than in passively heat-stressed younger adults. In a randomized, crossover design, 15 older (age: 69 ± 5 yr) and 14 younger (age: 30 ± 4 yr) healthy subjects underwent passive heat stress and time control trials. Cognitive tests (outcomes: accuracy and reaction time) from the CANTAB battery evaluated attention [rapid visual processing (RVP), choice reaction time (CRT)], memory [spatial span (SSP), pattern recognition memory (PRM)], and executive function [one touch stockings of Cambridge (OTS)]. Testing was undertaken on two occasions during each trial, at baseline and after internal temperature had increased by 1.0 ± 0.2°C or after a time control period. For tests that measured attention, reaction time during RVP and CRT was slower (P ≤ 0.01) in the older group. During heat stress, RVP reaction time improved (P < 0.01) in both groups. Heat stress had no effect (P ≥ 0.09) on RVP or CRT accuracy in either group. For tests that measured memory, accuracy on SSP and PRM was lower (P < 0.01) in the older group, but there was no effect of heat stress (P ≥ 0.14). For tests that measured executive function, overall, accuracy on OTS was lower, and reaction time was slower in the older group (P ≤ 0.05). Reaction time generally improved during heat stress, but there was no effect of heat stress on accuracy in either group. These data indicate that moderate increases in body temperature during passive heat stress do not differentially compromise cognitive function in younger and older adults. PMID:25786484

  6. Transgenic sickle cell trait mice do not exhibit abnormal thermoregulatory and stress responses to heat shock exposure.

    PubMed

    Chen, Yifan; Islam, Aminul

    2016-07-01

    There remains controversy over whether individuals with sickle cell trait (SCT) are vulnerable to health risks during physical activity in high temperatures. We examined thermoregulatory and stress-related responses to heat exposure in SCT and wild-type (WT) mice. No significant differences in core temperature (Tc) were observed between SCT and WT mice during heat exposure. There was no correlation between peak Tc during heat exposure and levels of hemoglobin S in SCT mice. Basal levels of circulating inflammatory and stress-related markers were not significantly different between SCT and WT mice. Although heat exposure caused significant increases in plasma interleukins 1β and 6, and 8-isoprostane in SCT and WT mice, no differences were found between SCT and WT mice with similar thermal response profiles during heat exposure. SCT mice had significantly higher expression of heat shock protein 72 in heart, liver and gastrocnemius muscle than WT mice under control and post-heat conditions. In conclusion, there is neither thermoregulatory dysfunction nor abnormal stress-related response in SCT mice exposed to moderate heat. The hemoglobin variant in mice is associated with altered tissue stress protein homeostasis. PMID:27282581

  7. Deteriorated Stress Response in Stationary-Phase Yeast: Sir2 and Yap1 Are Essential for Hsf1 Activation by Heat Shock and Oxidative Stress, Respectively

    PubMed Central

    Cohen, Aviv; Bar-Nun, Shoshana

    2014-01-01

    Stationary-phase cultures have been used as an important model of aging, a complex process involving multiple pathways and signaling networks. However, the molecular processes underlying stress response of non-dividing cells are poorly understood, although deteriorated stress response is one of the hallmarks of aging. The budding yeast Saccharomyces cerevisiae is a valuable model organism to study the genetics of aging, because yeast ages within days and are amenable to genetic manipulations. As a unicellular organism, yeast has evolved robust systems to respond to environmental challenges. This response is orchestrated largely by the conserved transcription factor Hsf1, which in S. cerevisiae regulates expression of multiple genes in response to diverse stresses. Here we demonstrate that Hsf1 response to heat shock and oxidative stress deteriorates during yeast transition from exponential growth to stationary-phase, whereas Hsf1 activation by glucose starvation is maintained. Overexpressing Hsf1 does not significantly improve heat shock response, indicating that Hsf1 dwindling is not the major cause for Hsf1 attenuated response in stationary-phase yeast. Rather, factors that participate in Hsf1 activation appear to be compromised. We uncover two factors, Yap1 and Sir2, which discretely function in Hsf1 activation by oxidative stress and heat shock. In Δyap1 mutant, Hsf1 does not respond to oxidative stress, while in Δsir2 mutant, Hsf1 does not respond to heat shock. Moreover, excess Sir2 mimics the heat shock response. This role of the NAD+-dependent Sir2 is supported by our finding that supplementing NAD+ precursors improves Hsf1 heat shock response in stationary-phase yeast, especially when combined with expression of excess Sir2. Finally, the combination of excess Hsf1, excess Sir2 and NAD+ precursors rejuvenates the heat shock response. PMID:25356557

  8. Differential proteomic analysis of grapevine leaves by iTRAQ reveals responses to heat stress and subsequent recovery

    PubMed Central

    2014-01-01

    Background High temperature is a major environmental factor limiting grape yield and affecting berry quality. Thermotolerance includes the direct response to heat stress and the ability to recover from heat stress. To better understand the mechanism of the thermotolerance of Vitis, we combined a physiological analysis with iTRAQ-based proteomics of Vitis vinifera cv Cabernet Sauvignon, subjected to 43°C for 6 h, and then followed by recovery at 25/18°C. Results High temperature increased the concentrations of TBARS and inhibited electronic transport in photosynthesis apparatus, indicating that grape leaves were damaged by heat stress. However, these physiological changes rapidly returned to control levels during the subsequent recovery phase from heat stress. One hundred and seventy-four proteins were differentially expressed under heat stress and/or during the recovery phase, in comparison to unstressed controls, respectively. Stress and recovery conditions shared 42 proteins, while 113 and 103 proteins were respectively identified under heat stress and recovery conditions alone. Based on MapMan ontology, functional categories for these dysregulated proteins included mainly photosynthesis (about 20%), proteins (13%), and stress (8%). The subcellular localization using TargetP showed most proteins were located in the chloroplasts (34%), secretory pathways (8%) and mitochondrion (3%). Conclusion On the basis of these findings, we proposed that some proteins related to electron transport chain of photosynthesis, antioxidant enzymes, HSPs and other stress response proteins, and glycolysis may play key roles in enhancing grapevine adaptation to and recovery capacity from heat stress. These results provide a better understanding of the proteins involved in, and mechanisms of thermotolerance in grapevines. PMID:24774513

  9. Antioxidant responses to heat and light stress differ with habitat in a common reef coral

    NASA Astrophysics Data System (ADS)

    Hawkins, Thomas D.; Krueger, Thomas; Wilkinson, Shaun P.; Fisher, Paul L.; Davy, Simon K.

    2015-12-01

    Coral bleaching—the stress-induced collapse of the coral- Symbiodinium symbiosis—is a significant driver of worldwide coral reef degradation. Yet, not all corals are equally susceptible to bleaching, and we lack a clear understanding of the mechanisms underpinning their differential susceptibilities. Here, we focus on cellular redox regulation as a potential determinant of bleaching susceptibility in the reef coral Stylophora pistillata. Using slow heating (1 °C d-1) and altered irradiance, we induced bleaching in S. pistillata colonies sampled from two depths [5-8 m (shallow) and 15-18 m (deep)]. There was significant depth-dependent variability in the timing and extent of bleaching (loss of symbiont cells), as well as in host enzymatic antioxidant activity [specifically, superoxide dismutase and catalase (CAT)]. However, among the coral fragments that bleached, most did so without displaying any evidence of a host enzymatic antioxidant response. For example, both deep and shallow corals suffered significant symbiont loss at elevated temperature, but only deep colonies exposed to high temperature and high light displayed any up-regulation of host antioxidant enzyme activity (CAT). Surprisingly, this preceded the equivalent antioxidant responses of the symbiont, which raises questions about the source(s) of hydrogen peroxide in the symbiosis. Overall, changes in enzymatic antioxidant activity in the symbionts were driven primarily by irradiance rather than temperature, and responses were similar across depth groups. Taken together, our results suggest that in the absence of light stress, heating of 1 °C d-1 to 4 °C above ambient is not sufficient to induce a substantial oxidative challenge in S. pistillata. We provide some of the first evidence that regulation of coral enzymatic antioxidants can vary significantly depending on habitat, and, in terms of determining bleaching susceptibility, our results suggest a significant role for the host's differential

  10. The response of Bacillus licheniformis to heat and ethanol stress and the role of the SigB regulon.

    PubMed

    Voigt, Birgit; Schroeter, Rebecca; Jürgen, Britta; Albrecht, Dirk; Evers, Stefan; Bongaerts, Johannes; Maurer, Karl-Heinz; Schweder, Thomas; Hecker, Michael

    2013-07-01

    The heat and ethanol stress response of Bacillus licheniformis DSM13 was analyzed at the transcriptional and/or translational level. During heat shock, regulons known to be heat-induced in Bacillus subtilis 168 are upregulated in B. licheniformis, such as the HrcA, SigB, CtsR, and CssRS regulon. Upregulation of the SigY regulon and of genes controlled by other extracytoplasmic function (ECF) sigma factors indicates a cell-wall stress triggered by the heat shock. Furthermore, tryptophan synthesis enzymes were upregulated in heat stressed cells as well as regulons involved in usage of alternative carbon and nitrogen sources. Ethanol stress led to an induction of the SigB, HrcA, and CtsR regulons. As indicated by the upregulation of a SigM-dependent protein, ethanol also triggered a cell wall stress. To characterize the SigB regulon of B. licheniformis, we analyzed the heat stress response of a sigB mutant. It is shown that the B. licheniformis SigB regulon comprises additional genes, some of which do not exist in B. subtilis, such as BLi03885, encoding a hypothetical protein, the Na/solute symporter gene BLi02212, the arginase homolog-encoding gene BLi00198 and mcrA, encoding a protein with endonuclease activity. PMID:23592518

  11. Different Responses to Heat Shock Stress Revealed Heteromorphic Adaptation Strategy of Pyropia haitanensis (Bangiales, Rhodophyta)

    PubMed Central

    Zhu, Zhujun; Yang, Rui; Qian, Feijian; Chen, Haimin; Yan, Xiaojun

    2014-01-01

    Pyropia has a unique heteromorphic life cycle with alternation stages between thallus and conchocelis, which lives at different water temperatures in different seasons. To better understand the different adaptation strategies for temperature stress, we tried to observe comparative biochemical changes of Pyropia haitanensis based on a short term heat shock model. The results showed that: (1) At normal temperature, free-living conchocelis contains significantly higher levels of H2O2, fatty acid-derived volatiles, the copy number of Phrboh and Phhsp70 genes,the activities of NADPH oxidase and floridoside than those in thallus. The released H2O2 and NADPH oxidase activity of conchocelis were more than 7 times higher than those of thallus. The copy number of Phrboh in conchocelis was 32 times that in thallus. (2) After experiencing heat shock at 35°C for 30 min, the H2O2 contents, the mRNA levels of Phrboh and Phhsp70, NADPH oxidase activity and the floridoside content in thallus were all significantly increased. The mRNA levels of Phrboh increased 5.78 times in 5 min, NADPH oxidase activity increased 8.45 times in 20 min. (3) Whereas, in conchocelis, the changes in fatty acids and their down-stream volatiles predominated, significantly increasing levels of saturated fatty acids and decreasing levels of polyunsaturated fatty acids occurred, and the 8-carbon volatiles were accumulated. However, the changes in H2O2 content and expression of oxidant-related genes and enzymatic activity were not obvious. Overall, these results indicate that conchocelis maintains a high level of active protective apparatus to endure its survival at high temperature, while thallus exhibit typical stress responses to heat shock. It is concluded that Pyropia haitanensis has evolved a delicate strategy for temperature adaptation for its heteromorphic life cycle. PMID:24709783

  12. Heat Stress Monitor

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The heavy, cumbersome body protection suits worn by members of hazardous materials response teams cause marked elevation of body temperatures, which can reduce effectiveness and lead to heat stress and injury. The CorTemp System, marketed by Human Technologies, Inc., provides the basis for a body temperature monitoring alarm system. Encased in a three-quarter-inch ingestible capsule, the system includes a mini-thermometer, miniature telemetry system, a microbattery and temperature sensor. It makes its way through the digestive system, continuously monitoring temperature. Findings are sent to the recorder by telemetry, and then displayed and stored for transfer to a computer.

  13. Environmental heat stress modulates thyroid status and its response to repeated endotoxin (LPS) challenge in steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thyroid hormones are important in the adaptation to heat stress, allowing the adjustment of metabolic rates in favor of decreased energy utilization and heat production. Thyroid status is compromised in a variety of acute and chronic infections and toxin-mediated disease states. Our objective was to...

  14. Sweat mineral element responses during 7 h of exercise-heat stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Uncertainty exists regarding the effect of sustained sweating on sweat mineral element composition. This study determined the effect of multiple hours of exercise-heat stress on sweat mineral concentrations. Seven heat acclimated subjects (6 males, 1 female) completed 5 consecutive 60 min bouts of...

  15. Proteomic and Physiological Analysis of the Response of Oat (Avena sativa) Seeds to Heat Stress under Different Moisture Conditions

    PubMed Central

    Chen, Lingling; Chen, Quanzhu; Kong, Lingqi; Xia, Fangshan; Yan, Huifang; Zhu, Yanqiao; Mao, Peisheng

    2016-01-01

    Seeds lose their viability when they are exposed to high temperature and moisture content (MC) during storage. The expression and metabolism of proteins plays a critical role in seed resistance to heat stress. However, the proteome response to heat stress in oat (Avena sativa) seeds during storage has not been revealed. To understand mechanisms of heat stress acclimation and tolerance in oat seeds, an integrated physiological and comparative proteomic analysis was performed on oat seeds with different MC during heat stress. Oat seeds with 10% and 16% MC were subjected to high temperatures (35, 45, and 50°C) for 24 and 2 days, respectively, and changes in physiological and biochemical characteristics were analyzed. The results showed that seed vigor decreased significantly with temperature increase from 35 to 50°C. Also, the proline content in 10% MC seeds decreased significantly (p < 0.05) whereas that in 16% MC seeds increased significantly (p < 0.05) during heat treatment from 35 to 50°C. There were no significant differences in malondialdehyde content in 10% MC seeds with temperature from 35 to 50°C, but a significant (p < 0.05) decline occurred in 16% MC seeds at 45°C. Proteome analysis revealed 21 significantly different proteins, including 19 down-regulated and two up-regulated proteins. The down-regulated proteins, notably six heat shock proteins and two ATP synthases, have important roles in the mobilization of carbohydrates and energy, and in the balance between synthesis and degradation of other proteins during seed deterioration. The up-regulation of argininosuccinate synthase participated in proline biosynthesis at 16% MC, which is important for maintaining reactive oxygen species homeostasis for the resistance of heat stress. In summary, heat-responsive protein species and mitochondrial respiratory metabolism were sensitive to high temperature and MC treatment. These studies provide a new insight into acclimation and tolerance to heat stress in

  16. Proteomic and Physiological Analysis of the Response of Oat (Avena sativa) Seeds to Heat Stress under Different Moisture Conditions.

    PubMed

    Chen, Lingling; Chen, Quanzhu; Kong, Lingqi; Xia, Fangshan; Yan, Huifang; Zhu, Yanqiao; Mao, Peisheng

    2016-01-01

    Seeds lose their viability when they are exposed to high temperature and moisture content (MC) during storage. The expression and metabolism of proteins plays a critical role in seed resistance to heat stress. However, the proteome response to heat stress in oat (Avena sativa) seeds during storage has not been revealed. To understand mechanisms of heat stress acclimation and tolerance in oat seeds, an integrated physiological and comparative proteomic analysis was performed on oat seeds with different MC during heat stress. Oat seeds with 10% and 16% MC were subjected to high temperatures (35, 45, and 50°C) for 24 and 2 days, respectively, and changes in physiological and biochemical characteristics were analyzed. The results showed that seed vigor decreased significantly with temperature increase from 35 to 50°C. Also, the proline content in 10% MC seeds decreased significantly (p < 0.05) whereas that in 16% MC seeds increased significantly (p < 0.05) during heat treatment from 35 to 50°C. There were no significant differences in malondialdehyde content in 10% MC seeds with temperature from 35 to 50°C, but a significant (p < 0.05) decline occurred in 16% MC seeds at 45°C. Proteome analysis revealed 21 significantly different proteins, including 19 down-regulated and two up-regulated proteins. The down-regulated proteins, notably six heat shock proteins and two ATP synthases, have important roles in the mobilization of carbohydrates and energy, and in the balance between synthesis and degradation of other proteins during seed deterioration. The up-regulation of argininosuccinate synthase participated in proline biosynthesis at 16% MC, which is important for maintaining reactive oxygen species homeostasis for the resistance of heat stress. In summary, heat-responsive protein species and mitochondrial respiratory metabolism were sensitive to high temperature and MC treatment. These studies provide a new insight into acclimation and tolerance to heat stress in

  17. Traditional Chinese Medicine Prescriptions Enhance Growth Performance of Heat Stressed Beef Cattle by Relieving Heat Stress Responses and Increasing Apparent Nutrient Digestibility

    PubMed Central

    Song, Xiaozhen; Luo, Junrong; Fu, Daibo; Zhao, Xianghui; Bunlue, Kornmatitsuk; Xu, Zhensong; Qu, Mingren

    2014-01-01

    The present aim was to investigate the effects of traditional Chinese medicine prescriptions (TCM) on body temperature, blood physiological parameters, nutrient apparent digestibility and growth performance of beef cattle under heat stress conditions. Twenty-seven beef cattle were randomly divided into three groups as following; i) high temperature control (HTC), ii) traditional Chinese medicine prescriptions I+high temperature (TCM I) and iii) traditional Chinese medicine prescriptions II+high temperature (TCM II) (n = 9 per group). The results showed that the mean body temperature declined in TCM II treatment (p<0.05). Serum T3 and T4 levels with TCM I and TCM II treatments elevated (p<0.05), and serum cortisol levels of TCM I treatments decreased (p<0.05), compared with the HTC group. Total protein, albumin, globulin in TCM II treatments elevated and blood urea nitrogen levels of both TCM treatments increased, but glucose levels of both TCM treatments decreased, compared with the HTC group (p<0.05). The apparent digestibility of organic matter and crude protein with TCM I treatment increased, and the apparent digestibility of acid detergent fiber elevated in both TCM treatments (p<0.05). Average daily feed intake was not different among three groups, however average daily gain increased and the feed:gain ratio decreased with both TCM treatments, compared with the HTC group (p<0.05). The present results suggest that dietary supplementation with TCM I or TCM II improves growth performance of heat stressed beef cattle by relieving heat stress responses and increasing nutrient apparent digestibility. PMID:25178304

  18. Heat Shock Protein 90 in Plants: Molecular Mechanisms and Roles in Stress Responses

    PubMed Central

    Xu, Zhao-Shi; Li, Zhi-Yong; Chen, Yang; Chen, Ming; Li, Lian-Cheng; Ma, You-Zhi

    2012-01-01

    The heat shock protein 90 (Hsp90) family mediates stress signal transduction, and plays important roles in the control of normal growth of human cells and in promoting development of tumor cells. Hsp90s have become a currently important subject in cellular immunity, signal transduction, and anti-cancer research. Studies on the physiological functions of Hsp90s began much later in plants than in animals and fungi. Significant progress has been made in understanding complex mechanisms of HSP90s in plants, including ATPase-coupled conformational changes and interactions with cochaperone proteins. A wide range of signaling proteins interact with HSP90s. Recent studies revealed that plant Hsp90s are important in plant development, environmental stress response, and disease and pest resistance. In this study, the plant HSP90 family was classified into three clusters on the basis of phylogenetic relationships, gene structure, and biological functions. We discuss the molecular functions of Hsp90s, and systematically review recent progress of Hsp90 research in plants. PMID:23443089

  19. The response of contrasting tomato genotypes to combined heat and drought stress.

    PubMed

    Nankishore, Alliea; Farrell, Aidan D

    2016-09-01

    Efforts to maximize yields of food crops can be undermined by abiotic stress factors, particularly those related to climate change. Here, we use a range of physiological methods to detect the individual and combined effects of heat and drought stress on three contrasting varieties of tomato: Hybrid 61, Moskvich, and Nagcarlang. Seedlings were acclimated under the following treatment regimes: CONTROL (25-36°C; well-watered), DRY (25-36°C; 20% field capacity), HOT (25-42°C; well-watered) and HOT+DRY (25-42°C; 20% field capacity). In each treatment, stomatal conductance, leaf temperature, chlorophyll content, and several chlorophyll fluorescence variables (both in situ and in vitro following a heat shock treatment) were measured. Plants from the HOT treatment remained statistically similar to the CONTROL plants in most of the measured parameters, while those from the DRY treatment and especially the HOT+DRY treatment showed clear effects of abiotic stress. Hybrid 61 showed considerable resilience to heat and drought stress compared to the other varieties, with significantly cooler leaves (one day after treatments imposed) and significantly higher Fv/Fm values both in situ and in vitro. The genotypic differences in resilience to heat stress were only apparent under water-limited conditions, highlighting the need to consider leaf temperature rather than air temperature when testing for tolerance to heat stress. The most effective parameters for discriminating genotypic variation in heat and drought stress were in vitro Fv/Fm and chlorophyll content. PMID:27467552

  20. Cerebrovascular responsiveness to steady-state changes in end-tidal CO2 during passive heat stress

    PubMed Central

    Low, David A.; Wingo, Jonathan E.; Keller, David M.; Davis, Scott L.; Zhang, Rong; Crandall, Craig G.

    2009-01-01

    This study tested the hypothesis that passive heat stress alters cerebrovascular responsiveness to steady-state changes in end-tidal CO2 (PetCO2). Nine healthy subjects (4 men and 5 women), each dressed in a water-perfused suit, underwent normoxic hypocapnic hyperventilation (decrease PetCO2 ~20 Torr) and normoxic hypercapnic (increase in PetCO2 ~9 Torr) challenges under normothermic and passive heat stress conditions. The slope of the relationship between calculated cerebrovascular conductance (CBVC; middle cerebral artery blood velocity/mean arterial blood pressure) and PetCO2 was used to evaluate cerebrovascular CO2 responsiveness. Passive heat stress increased core temperature (1.1 ± 0.2°C, P < 0.001) and reduced middle cerebral artery blood velocity by 8 ± 8 cm/s (P = 0.01), reduced CBVC by 0.09 ± 0.09 CBVC units (P = 0.02), and decreased PetCO2 by 3 ± 4 Torr (P = 0.07), while mean arterial blood pressure was well maintained (P = 0.36). The slope of the CBVC-PetCO2 relationship to the hypocapnic challenge was not different between normothermia and heat stress conditions (0.009 ± 0.006 vs. 0.009 ± 0.004 CBVC units/Torr, P = 0.63). Similarly, in response to the hypercapnic challenge, the slope of the CBVC-PetCO2 relationship was not different between normothermia and heat stress conditions (0.028 ± 0.020 vs. 0.023 ± 0.008 CBVC units/Torr, P = 0.31). These results indicate that cerebrovascular CO2 responsiveness, to the prescribed steady-state changes in PetCO2, is unchanged during passive heat stress. PMID:18218916

  1. Perspectives on deciphering mechanisms underlying plant heat stress response and thermotolerance

    PubMed Central

    Bokszczanin, Kamila L.; Fragkostefanakis, Sotirios

    2013-01-01

    Global warming is a major threat for agriculture and food safety and in many cases the negative effects are already apparent. The current challenge of basic and applied plant science is to decipher the molecular mechanisms of heat stress response (HSR) and thermotolerance in detail and use this information to identify genotypes that will withstand unfavorable environmental conditions. Nowadays X-omics approaches complement the findings of previous targeted studies and highlight the complexity of HSR mechanisms giving information for so far unrecognized genes, proteins and metabolites as potential key players of thermotolerance. Even more, roles of epigenetic mechanisms and the involvement of small RNAs in thermotolerance are currently emerging and thus open new directions of yet unexplored areas of plant HSR. In parallel it is emerging that although the whole plant is vulnerable to heat, specific organs are particularly sensitive to elevated temperatures. This has redirected research from the vegetative to generative tissues. The sexual reproduction phase is considered as the most sensitive to heat and specifically pollen exhibits the highest sensitivity and frequently an elevation of the temperature just a few degrees above the optimum during pollen development can have detrimental effects for crop production. Compared to our knowledge on HSR of vegetative tissues, the information on pollen is still scarce. Nowadays, several techniques for high-throughput X-omics approaches provide major tools to explore the principles of pollen HSR and thermotolerance mechanisms in specific genotypes. The collection of such information will provide an excellent support for improvement of breeding programs to facilitate the development of tolerant cultivars. The review aims at describing the current knowledge of thermotolerance mechanisms and the technical advances which will foster new insights into this process. PMID:23986766

  2. Dissecting the proteome dynamics of the early heat stress response leading to plant survival or death in Arabidopsis.

    PubMed

    Echevarría-Zomeño, Sira; Fernández-Calvino, Lourdes; Castro-Sanz, Ana B; López, Juan Antonio; Vázquez, Jesús; Castellano, M Mar

    2016-06-01

    In many plant species, an exposure to a sublethal temperature triggers an adaptative response called acclimation. This response involves an extensive molecular reprogramming that allows the plant to further survive to an otherwise lethal increase of temperature. A related response is also launched under an abrupt and lethal heat stress that, in this case, is unable to successfully promote thermotolerance and therefore ends up in plant death. Although these molecular programmes are expected to have common players, the overlapping degree and the specific regulators of each process are currently unknown. We have carried out a high-throughput comparative proteomics analysis during acclimation and during the early stages of the plant response to a severe heat stress that lead Arabidopsis seedlings either to survival or death. This analysis dissects these responses, unravels the common players and identifies the specific proteins associated with these different fates. Thermotolerance assays of mutants in genes with an uncharacterized role in heat stress demonstrate the relevance of this study to uncover both positive and negative heat regulators and pinpoint a pivotal role of JR1 and BAG6 in heat tolerance. PMID:26580143

  3. The oxygen reduction pathway and heat shock stress response are both required for Entamoeba histolytica pathogenicity.

    PubMed

    Olivos-García, Alfonso; Saavedra, Emma; Nequiz, Mario; Santos, Fabiola; Luis-García, Erika Rubí; Gudiño, Marco; Pérez-Tamayo, Ruy

    2016-05-01

    Several species belonging to the genus Entamoeba can colonize the mouth or the human gut; however, only Entamoeba histolytica is pathogenic to the host, causing the disease amoebiasis. This illness is responsible for one hundred thousand human deaths per year worldwide, affecting mainly underdeveloped countries. Throughout its entire life cycle and invasion of human tissues, the parasite is constantly subjected to stress conditions. Under in vitro culture, this microaerophilic parasite can tolerate up to 5 % oxygen concentrations; however, during tissue invasion the parasite has to cope with the higher oxygen content found in well-perfused tissues (4-14 %) and with reactive oxygen and nitrogen species derived from both host and parasite. In this work, the role of the amoebic oxygen reduction pathway (ORP) and heat shock response (HSP) are analyzed in relation to E. histolytica pathogenicity. The data suggest that in contrast with non-pathogenic E. dispar, the higher level of ORP and HSPs displayed by E. histolytica enables its survival in tissues by diminishing and detoxifying intracellular oxidants and repairing damaged proteins to allow metabolic fluxes, replication and immune evasion. PMID:26589893

  4. Genetic Variations of Physiological Responses Following Heat Stress in Laying Hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress (HS), also known as hyperthermia, is a major problem experienced by poultry during high-temperature conditions. The ability to manage the detrimental effects of HS can be attributed to many factors, including genetics. The objective of the present study was to determine the variation of ...

  5. Changes in the Heat Stress Response of Laying Hens Following Antioxidant Supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress (HS) is a major contributor to mortality and other welfare issues in the poultry industry. The objective of this study was to determine the benefits of an antioxidant supplement during HS. One hundred and twenty White Leghorns at 32 wk of age were randomly transferred to two adjacent roo...

  6. Cross-omics comparison of stress responses in mesothelial cells exposed to heat- versus filter-sterilized peritoneal dialysis fluids.

    PubMed

    Kratochwill, Klaus; Bender, Thorsten O; Lichtenauer, Anton M; Herzog, Rebecca; Tarantino, Silvia; Bialas, Katarzyna; Jörres, Achim; Aufricht, Christoph

    2015-01-01

    Recent research suggests that cytoprotective responses, such as expression of heat-shock proteins, might be inadequately induced in mesothelial cells by heat-sterilized peritoneal dialysis (PD) fluids. This study compares transcriptome data and multiple protein expression profiles for providing new insight into regulatory mechanisms. Two-dimensional difference gel electrophoresis (2D-DIGE) based proteomics and topic defined gene expression microarray-based transcriptomics techniques were used to evaluate stress responses in human omental peritoneal mesothelial cells in response to heat- or filter-sterilized PD fluids. Data from selected heat-shock proteins were validated by 2D western-blot analysis. Comparison of proteomics and transcriptomics data discriminated differentially regulated protein abundance into groups depending on correlating or noncorrelating transcripts. Inadequate abundance of several heat-shock proteins following exposure to heat-sterilized PD fluids is not reflected on the mRNA level indicating interference beyond transcriptional regulation. For the first time, this study describes evidence for posttranscriptional inadequacy of heat-shock protein expression by heat-sterilized PD fluids as a novel cytotoxic property. Cross-omics technologies introduce a novel way of understanding PDF bioincompatibility and searching for new interventions to reestablish adequate cytoprotective responses. PMID:26495307

  7. Coordination of chemical (trimethylamine oxide) and molecular (heat shock protein 70) chaperone responses to heat stress in elasmobranch red blood cells.

    PubMed

    Kolhatkar, Ashra; Robertson, Cayleih E; Thistle, Maria E; Gamperl, A Kurt; Currie, Suzanne

    2014-01-01

    Chemical and molecular chaperones are organic compounds that protect and stabilize proteins from damage and aggregation as a result of cellular stress. Using the dogfish (Squalus acanthias) red blood cell (RBC) as a model, we examined whether elasmobranch cells with naturally high concentrations of the chemical chaperone trimethylamine oxide (TMAO) would induce the molecular chaperone heat shock protein 70 (HSP70) when exposed to an acute thermal stress. Our hypothesis was that TMAO is itself capable of preventing damage and preserving cellular function during thermal stress and thus that the heat shock response would be inhibited/diminished. We incubated RBCs in vitro with and without physiologically relevant concentrations of TMAO at 13°C and then exposed cells to a 1-h acute heat shock at 24°C. HSP70 protein expression was elevated in dogfish RBCs after the acute heat stress, but this induction was inhibited by extracellular TMAO. Regardless of the presence of TMAO and/or HSP70, we did not observe any cell damage, as indicated by changes in caspase 3/7 activity, protein carbonyls, membrane viability, or levels of ubiquitin. We also saw no change in RBC cell function, as determined by hemoglobin oxygen affinity or carrying capacity, in cells lacking the heat shock response but protected by TMAO. This study demonstrates that there is cellular coordination between chemical and molecular chaperones in response to an acute thermal stress in dogfish RBCs and suggests that TMAO has a thermoprotective role in these cells, thus eliminating the need for a heat shock response. PMID:25244377

  8. Thermal stress response of General Purpose Heat Source (GPHS) aeroshell material

    NASA Technical Reports Server (NTRS)

    Grinberg, I. M.; Hulbert, L. E.; Luce, R. G.

    1980-01-01

    A thermal stress test was conducted to determine the ability of the GPHS aeroshell 3 D FWPF material to maintain physical integrity when exposed to a severe heat flux such as would occur from prompt reentry of GPHS modules. The test was performed in the Giant Planetary Facility at NASA's Ames Research Center. Good agreement was obtained between the theoretical and experimental results for both temperature and strain time histories. No physical damage was observed in the test specimen. These results provide initial corroboration both of the analysis techniques and that the GPHS reentry member will survive the reentry thermal stress levels expected.

  9. Protecting Yourself from Heat Stress

    MedlinePlus

    ... Contact NIOSH NIOSH Fast Facts: Protecting Yourself from Heat Stress Language: English Español (Spanish) Kreyol Haitien (Haitian ... as heat stroke, heat exhaustion, or heat cramps. Heat Stroke A condition that occurs when the body ...

  10. Impact of short-term heat stress on physiological responses and expression profile of HSPs in Barbari goats

    NASA Astrophysics Data System (ADS)

    Dangi, Satyaveer Singh; Gupta, Mahesh; Nagar, Vimla; Yadav, Vijay Pratap; Dangi, Saroj K.; Shankar, Om; Chouhan, Vikrant Singh; Kumar, Puneet; Singh, Gyanendra; Sarkar, Mihir

    2014-12-01

    Six, nonpregnant, Barbari goats aged 4-5 years were selected for the study. For the first 6 days, the animals were kept in psychrometric chamber at thermoneutral temperature for 6 h each day to make them acclimated to climatic chamber. On the 7th day, the animals were exposed to 41 °C temperature for 3 h and then to 45 °C for the next 3 h. Cardinal physiological responses were measured, and blood samples (3 ml) were collected at 1-h interval during the heat exposure period and then once after 6 h of the heat exposure. The rectal temperature (RT) and respiratory rate (RR) increased significantly ( P < 0.05) during the heat exposure compared to pre- and postexposure. The relative messenger RNA (mRNA) expression of heat shock protein (HSP)60, HSP70, and HSP90 increased significantly ( P < 0.05) within 1 h after exposure to heat stress at 41 and 45 °C and decreased significantly ( P < 0.05) in next 2 h but remain significantly ( P < 0.05) elevated from preexposure. HSP105/110 relative mRNA expression level remained unchanged during the first 4 h, and thereafter, it increased significantly ( P < 0.05) and reached the peak at 6 h. Relative protein expression pattern of HSPs during exposure to heat stress showed similar trend as observed for the relative mRNA expression. Given the response sensitivity and intensity of HSP genes to environmental stresses, HSP70 was found to be the most sensitive to temperature fluctuation, and it could be used as an important molecular biomarker to heat stress in animals.

  11. A novel heat shock protein alpha 8 (Hspa8) molecular network mediating responses to stress- and ethanol-related behaviors.

    PubMed

    Urquhart, Kyle R; Zhao, Yinghong; Baker, Jessica A; Lu, Ye; Yan, Lei; Cook, Melloni N; Jones, Byron C; Hamre, Kristin M; Lu, Lu

    2016-04-01

    Genetic differences mediate individual differences in susceptibility and responses to stress and ethanol, although, the specific molecular pathways that control these responses are not fully understood. Heat shock protein alpha 8 (Hspa8) is a molecular chaperone and member of the heat shock protein family that plays an integral role in the stress response and that has been implicated as an ethanol-responsive gene. Therefore, we assessed its role in mediating responses to stress and ethanol across varying genetic backgrounds. The hippocampus is an important mediator of these responses, and thus, was examined in the BXD family of mice in this study. We conducted bioinformatic analyses to dissect genetic factors modulating Hspa8 expression, identify downstream targets of Hspa8, and examined its role. Hspa8 is trans-regulated by a gene or genes on chromosome 14 and is part of a molecular network that regulates stress- and ethanol-related behaviors. To determine additional components of this network, we identified direct or indirect targets of Hspa8 and show that these genes, as predicted, participate in processes such as protein folding and organic substance metabolic processes. Two phenotypes that map to the Hspa8 locus are anxiety-related and numerous other anxiety- and/or ethanol-related behaviors significantly correlate with Hspa8 expression. To more directly assay this relationship, we examined differences in gene expression following exposure to stress or alcohol and showed treatment-related differential expression of Hspa8 and a subset of the members of its network. Our findings suggest that Hspa8 plays a vital role in genetic differences in responses to stress and ethanol and their interactions. PMID:26780340

  12. Global crop yield response to extreme heat stress under multiple climate change futures

    NASA Astrophysics Data System (ADS)

    Deryng, D.; Conway, D.; Ramankutty, N.; Price, J.; Warren, R.

    2014-12-01

    Extreme heat stress during the crop reproductive period can be critical for crop productivity. Projected changes in the frequency and severity of extreme climatic events are expected to negatively impact crop yields and global food production. This study applies the global crop model PEGASUS to quantify, for the first time at the global scale, impacts of extreme heat stress on maize, spring wheat and soybean yields resulting from 72 climate change scenarios for the 21st century. Our results project maize to face progressively worse impacts under a range of RCPs but spring wheat and soybean to improve globally through to the 2080s due to CO2 fertilization effects, even though parts of the tropic and sub-tropic regions could face substantial yield declines. We find extreme heat stress at anthesis (HSA) by the 2080s (relative to the 1980s) under RCP 8.5, taking into account CO2 fertilization effects, could double global losses of maize yield (dY = -12.8 ± 6.7% versus -7.0 ± 5.3% without HSA), reduce projected gains in spring wheat yield by half (dY = 34.3 ± 13.5% versus 72.0 ± 10.9% without HSA) and in soybean yield by a quarter (dY = 15.3 ± 26.5% versus 20.4 ± 22.1% without HSA). The range reflects uncertainty due to differences between climate model scenarios; soybean exhibits both positive and negative impacts, maize is generally negative and spring wheat generally positive. Furthermore, when assuming CO2 fertilization effects to be negligible, we observe drastic climate mitigation policy as in RCP 2.6 could avoid more than 80% of the global average yield losses otherwise expected by the 2080s under RCP 8.5. We show large disparities in climate impacts across regions and find extreme heat stress adversely affects major producing regions and lower income countries.

  13. Global crop yield response to extreme heat stress under multiple climate change futures

    NASA Astrophysics Data System (ADS)

    Deryng, Delphine; Conway, Declan; Ramankutty, Navin; Price, Jeff; Warren, Rachel

    2014-03-01

    Extreme heat stress during the crop reproductive period can be critical for crop productivity. Projected changes in the frequency and severity of extreme climatic events are expected to negatively impact crop yields and global food production. This study applies the global crop model PEGASUS to quantify, for the first time at the global scale, impacts of extreme heat stress on maize, spring wheat and soybean yields resulting from 72 climate change scenarios for the 21st century. Our results project maize to face progressively worse impacts under a range of RCPs but spring wheat and soybean to improve globally through to the 2080s due to CO2 fertilization effects, even though parts of the tropic and sub-tropic regions could face substantial yield declines. We find extreme heat stress at anthesis (HSA) by the 2080s (relative to the 1980s) under RCP 8.5, taking into account CO2 fertilization effects, could double global losses of maize yield (ΔY = -12.8 ± 6.7% versus - 7.0 ± 5.3% without HSA), reduce projected gains in spring wheat yield by half (ΔY = 34.3 ± 13.5% versus 72.0 ± 10.9% without HSA) and in soybean yield by a quarter (ΔY = 15.3 ± 26.5% versus 20.4 ± 22.1% without HSA). The range reflects uncertainty due to differences between climate model scenarios; soybean exhibits both positive and negative impacts, maize is generally negative and spring wheat generally positive. Furthermore, when assuming CO2 fertilization effects to be negligible, we observe drastic climate mitigation policy as in RCP 2.6 could avoid more than 80% of the global average yield losses otherwise expected by the 2080s under RCP 8.5. We show large disparities in climate impacts across regions and find extreme heat stress adversely affects major producing regions and lower income countries.

  14. Day and night heat stress trigger different transcriptomic responses in green and ripening grapevine (vitis vinifera) fruit

    PubMed Central

    2014-01-01

    Background Global climate change will noticeably affect plant vegetative and reproductive development. The recent increase in temperatures has already impacted yields and composition of berries in many grapevine-growing regions. Physiological processes underlying temperature response and tolerance of the grapevine fruit have not been extensively investigated. To date, all studies investigating the molecular regulation of fleshly fruit response to abiotic stress were only conducted during the day, overlooking possible critical night-specific variations. The present study explores the night and day transcriptomic response of grapevine fruit to heat stress at several developmental stages. Short heat stresses (2 h) were applied at day and night to vines bearing clusters sequentially ordered according to the developmental stages along their vertical axes. The recently proposed microvine model (DRCF-Dwarf Rapid Cycling and Continuous Flowering) was grown in climatic chambers in order to circumvent common constraints and biases inevitable in field experiments with perennial macrovines. Post-véraison berry heterogeneity within clusters was avoided by constituting homogenous batches following organic acids and sugars measurements of individual berries. A whole genome transcriptomic approach was subsequently conducted using NimbleGen 090818 Vitis 12X (30 K) microarrays. Results Present work reveals significant differences in heat stress responsive pathways according to day or night treatment, in particular regarding genes associated with acidity and phenylpropanoid metabolism. Precise distinction of ripening stages led to stage-specific detection of malic acid and anthocyanin-related transcripts modulated by heat stress. Important changes in cell wall modification related processes as well as indications for heat-induced delay of ripening and sugar accumulation were observed at véraison, an effect that was reversed at later stages. Conclusions This first day - night

  15. Stress and heat flow

    SciTech Connect

    Lachenbrunch, A.H.; McGarr, A.

    1990-01-01

    As the Pacific plate slides northward past the North American plate along the San Andreas fault, the frictional stress that resists plate motion there is overcome to cause earthquakes. However, the frictional heating predicted for the process has never been detected. Thus, in spite of its importance to an understanding of both plate motion and earthquakes, the size of this frictional stress is still uncertain, even in order of magnitude.

  16. Impact of Moderate Heat, Carvacrol, and Thymol Treatments on the Viability, Injury, and Stress Response of Listeria monocytogenes.

    PubMed

    Guevara, L; Antolinos, V; Palop, A; Periago, P M

    2015-01-01

    The microbial safety and stability of minimally processed foods are based on the application of combined preservative factors. Since microorganisms are able to develop adaptive networks to survive under conditions of stress, food safety may be affected, and therefore understanding of stress adaptive mechanisms plays a key role in designing safe food processing conditions. In the present study, the viability and the sublethal injury of Listeria monocytogenes exposed to moderate heat (55 °C) and/or essential oil compounds (carvacrol and thymol, 0.3 mM) treatments were studied. Synergistic effects were obtained when combining mild heat (55 °C) with one or both essential oil compounds, leading to inactivation kinetics values three to four times lower than when using heat alone. All the treatments applied caused some injury in the population. The injury levels ranged from around 20% of the surviving population under the mildest conditions to more than 99.99% under the most stringent conditions. Protein extracts of cells exposed to these treatments were analysed by two-dimensional gel electrophoresis. The results obtained revealed that stressed cells exhibited differential protein expression to control cells. The proteins upregulated under these stressing conditions were implicated, among other functions, in stress response, metabolism, and protein refolding. PMID:26539510

  17. Impact of Moderate Heat, Carvacrol, and Thymol Treatments on the Viability, Injury, and Stress Response of Listeria monocytogenes

    PubMed Central

    Guevara, L.; Antolinos, V.; Palop, A.; Periago, P. M.

    2015-01-01

    The microbial safety and stability of minimally processed foods are based on the application of combined preservative factors. Since microorganisms are able to develop adaptive networks to survive under conditions of stress, food safety may be affected, and therefore understanding of stress adaptive mechanisms plays a key role in designing safe food processing conditions. In the present study, the viability and the sublethal injury of Listeria monocytogenes exposed to moderate heat (55°C) and/or essential oil compounds (carvacrol and thymol, 0.3 mM) treatments were studied. Synergistic effects were obtained when combining mild heat (55°C) with one or both essential oil compounds, leading to inactivation kinetics values three to four times lower than when using heat alone. All the treatments applied caused some injury in the population. The injury levels ranged from around 20% of the surviving population under the mildest conditions to more than 99.99% under the most stringent conditions. Protein extracts of cells exposed to these treatments were analysed by two-dimensional gel electrophoresis. The results obtained revealed that stressed cells exhibited differential protein expression to control cells. The proteins upregulated under these stressing conditions were implicated, among other functions, in stress response, metabolism, and protein refolding. PMID:26539510

  18. Production and physiological responses of heat-stressed lactating dairy cattle to conductive cooling.

    PubMed

    Perano, Kristen M; Usack, Joseph G; Angenent, Largus T; Gebremedhin, Kifle G

    2015-08-01

    The objective of this research was to test the effectiveness of conductive cooling in alleviating heat stress of lactating dairy cows. A conductive cooling system was built with waterbeds (Dual Chamber Cow Waterbeds, Advanced Comfort Technology Inc., Reedsburg, WI) modified to circulate chilled water. The experiment lasted 7 wk. Eight first-lactation Holstein cows producing 34.4±3.7kg/d of milk at 166±28 d in milk were used in the study. Milk yield, dry matter intake (DMI), and rectal temperature were recorded twice daily, and respiration rate was recorded 5 times per day. During wk 1, the cows were not exposed to experimental heat stress or conductive cooling. For the remaining 6 wk, the cows were exposed to heat stress from 0900 to 1700h each day. During these 6 wk, 4 of the 8 cows were cooled with conductive cooling (experimental cows), and the other 4 were not cooled (control cows). The study consisted of 2 thermal environment exposures (temperature-humidity index mean ± standard deviation of 80.7±0.9 and 79.0±1.0) and 2 cooling water temperatures (circulating water through the water mattresses at temperatures of 4.5°C and 10°C). Thus, a total of 4 conductive cooling treatments were tested, with each treatment lasting 1 wk. During wk 6, the experimental and control cows were switched and the temperature-humidity index of 79.0±1.0 with 4.5°C cooling water treatment was repeated. During wk 7, waterbeds were placed directly on concrete stalls without actively cooling the water. Least squares means and P-values for the different treatments were calculated with multivariate mixed models. Conductively cooling the cows with 4.5°C water decreased rectal temperature by 1.0°C, decreased respiration rate by 18 breaths/min, increased milk yield by 5%, and increased DMI by 14% compared with the controls. When the results from the 2 cooling water temperatures (4.5°C and 10°C circulating water) were compared, we found that the rectal temperature from 4.5

  19. Beneficial effect of Oligonol supplementation on sweating response under heat stress in humans.

    PubMed

    Lee, Jeong Beom; Shin, Young Oh

    2014-10-01

    Oligonol is a low-molecular weight polyphenol that possesses antioxidant and anti-inflammatory properties. However, nothing is known regarding the impact of Oligonol on sudomotor activity. This study investigated the effects of Oligonol supplementation on sudomotor activity during heat load in humans. Initially, we conducted a placebo-controlled, cross-over trial where participants took a daily dose of Oligonol 200 mg or placebo for one week. After a 2 week washout period, the subjects were switched to the other study arm. As a heat load, half-body immersion into hot water (42 ± 0.5 °C for 30 min) was performed in an automated climate chamber. Tympanic and skin temperatures were measured. Sudomotor activity, including onset time, sweat rate (SR) and volume (SV), active sweat gland density (ASGD), and sweat gland output (SGO), was tested in four or eight areas of skin. When compared with placebo, Oligonol attenuated increases in tympanic and skin temperatures after the heat load. There was an increasing trend in local sweat onset time, but there was a decrease in local SR, SV, ASGD, and SGO for Oligonol compared to placebo. The mean ASGD was significantly higher in the Oligonol group than in the placebo group for 10, 20, and 30 min. This study demonstrates that Oligonol appears to be worthy of consideration as a natural supplement to support more economical use of body fluids against heat stress. PMID:25124490

  20. Menstrual cycle and sex affect hemodynamic responses to combined orthostatic and heat stress.

    PubMed

    Meendering, Jessica R; Torgrimson, Britta N; Houghton, Belinda L; Halliwill, John R; Minson, Christopher T

    2005-08-01

    Women have decreased orthostatic tolerance compared with men, and anecdotal evidence suggests women are more susceptible to orthostatic intolerance in warm environments. Because estrogen and progesterone affect numerous physiological variables that may alter orthostatic tolerance, the purpose of our study was to compare orthostatic tolerance across the menstrual cycle phases in women during combined orthostatic and heat stress and to compare these data with those of men. Eight normally menstruating women and eight males (22 +/- 4.0 and 23 +/- 3.5 yr, respectively) completed the protocol. Women were studied during their early follicular (EF), ovulatory (OV), and midluteal (ML) phases. Men were studied twice within 2-4 wk. Heart rate, cardiac output, blood pressure, core temperature (T(c)), and cutaneous vascular conductance (CVC) were measured during three head-up tilt tests, consisting of two tilts in the thermoneutral condition and one tilt after a 0.5 degrees C rise in T(c). There was no difference in orthostatic tolerance across the menstrual cycle phases, despite higher CVC in the ML phase after heating (EF, 42.3 +/- 4.8; OV, 40.1 +/- 3.7; ML, 57.5 +/- 4.5; P < 0.05). Orthostatic tolerance in the heat was greater in men than women (P < 0.05). These data suggest that although many physiological variables associated with blood pressure regulation fluctuate during the menstrual cycle, orthostatic tolerance in the heat remains unchanged. Additionally, our data support a clear sex difference in orthostatic tolerance and extend upon previous data to show that the sex difference in the heat is not attributable to fluctuating hormone profiles during the menstrual cycle. PMID:15778279

  1. Response of heat shock protein genes of the oriental fruit moth under diapause and thermal stress reveals multiple patterns dependent on the nature of stress exposure.

    PubMed

    Zhang, Bo; Peng, Yu; Zheng, Jincheng; Liang, Lina; Hoffmann, Ary A; Ma, Chun-Sen

    2016-07-01

    Heat shock protein gene (Hsp) families are thought to be important in thermal adaptation, but their expression patterns under various thermal stresses have still been poorly characterized outside of model systems. We have therefore characterized Hsp genes and their stress responses in the oriental fruit moth (OFM), Grapholita molesta, a widespread global orchard pest, and compared patterns of expression in this species to that of other insects. Genes from four Hsp families showed variable expression levels among tissues and developmental stages. Members of the Hsp40, 70, and 90 families were highly expressed under short exposures to heat and cold. Expression of Hsp40, 70, and Hsc70 family members increased in OFM undergoing diapause, while Hsp90 was downregulated. We found that there was strong sequence conservation of members of large Hsp families (Hsp40, Hsp60, Hsp70, Hsc70) across taxa, but this was not always matched by conservation of expression patterns. When the large Hsps as well as small Hsps from OFM were compared under acute and ramping heat stress, two groups of sHsps expression patterns were apparent, depending on whether expression increased or decreased immediately after stress exposure. These results highlight potential differences in conservation of function as opposed to sequence in this gene family and also point to Hsp genes potentially useful as bioindicators of diapause and thermal stress in OFM. PMID:27125786

  2. Dynamics of the Heat Stress Response of Ceramides with Different Fatty-Acyl Chain Lengths in Baker's Yeast.

    PubMed

    Chen, Po-Wei; Fonseca, Luis L; Hannun, Yusuf A; Voit, Eberhard O

    2015-08-01

    The article demonstrates that computational modeling has the capacity to convert metabolic snapshots, taken sequentially over time, into a description of cellular, dynamic strategies. The specific application is a detailed analysis of a set of actions with which Saccharomyces cerevisiae responds to heat stress. Using time dependent metabolic concentration data, we use a combination of mathematical modeling, reverse engineering, and optimization to infer dynamic changes in enzyme activities within the sphingolipid pathway. The details of the sphingolipid responses to heat stress are important, because they guide some of the longer-term alterations in gene expression, with which the cells adapt to the increased temperature. The analysis indicates that all enzyme activities in the system are affected and that the shapes of the time trends in activities depend on the fatty-acyl CoA chain lengths of the different ceramide species in the system. PMID:26241868

  3. SpiE interacts with Corynebacterium glutamicum WhcE and is involved in heat and oxidative stress responses.

    PubMed

    Park, Jung Chul; Park, Joon-Song; Kim, Younhee; Kim, Pil; Kim, Eung Soo; Lee, Heung-Shick

    2016-05-01

    The gene whcE in Corynebacterium glutamicum positively responds to oxidative and heat stress. To search for proteins that interact with WhcE, we employed a two-hybrid system with WhcE as the bait. Sequencing analysis of the isolated clones revealed peptide sequences, one of which showed high sequence identity to a hydrophobe/amphiphile efflux-1 family transporter encoded by NCgl1497. The interaction of the NCgl1497-encoded protein with WhcE in vivo was verified using reporter gene expression by real-time quantitative PCR (RT-qPCR). The WhcE protein strongly interacted with the NCgl1497-encoded protein in the presence of oxidative and heat stress. Furthermore, purified WhcE and NCgl1497-encoded proteins interacted in vitro, especially in the presence of the oxidant diamide, and the protein-protein interaction was disrupted in the presence of the reductant dithiothreitol. In addition, the transcription of NCgl1497 was activated approximately twofold in diamide- or heat-treated cells. To elucidate the function of the NCgl497 gene, an NCgl1497-deleted mutant strain was constructed. The mutant showed decreased viability in the presence of diamide and heat stress. The mutant strain also exhibited reduced transcription of the thioredoxin reductase gene, which is known to be regulated by whcE. Based on the results, NCgl1497 was named spiE (stress protein interacting with WhcE). Collectively, our data suggest that spiE is involved in the whcE-mediated oxidative stress response pathway of C. glutamicum. PMID:26996627

  4. Environmental heat stress modulates thyroid status and its response to repeated endotoxin challenge in steers.

    PubMed

    Kahl, S; Elsasser, T H; Rhoads, R P; Collier, R J; Baumgard, L H

    2015-07-01

    The objective of this study was to evaluate in cattle, the effects of acute exposure to a heat stress (HS) environment on the status of the pituitary (thyrotropin, TSH)-thyroid (thyroxine, T4)-peripheral tissue T4 deiodination (type 1 5'-deiodinase [D1]; triiodothyronine [T3]; reverse-triiodothyronine [rT3]) axis, and the further response of this pituitary-thyroid-peripheral tissue axis (PTTA) to perturbation caused by the induction of the proinflammatory innate immune state provoked by the administration of gram-negative bacteria endotoxin (lipopolysaccharide [LPS]). Ten steers (318 ± 49 kg body weight) housed in controlled environment chambers were subjected to either a thermoneutral (TN: constant 19°C) or HS temperature conditions (cyclical daily temperatures: 32.2°C-40.0°C) for a total period of 9 d. To minimize the effects of altered plane of nutrition due to HS, steers in TN were pair-fed to animals in HS conditions. Steers received 2 LPS challenges 3 d apart (LPS1 and LPS2; 0.2 μg/kg body weight, intravenously, Escherichia coli 055:B5) with the first challenge administered on day 4 relative to the start of the environmental conditioning. Jugular blood samples were collected at 0, 1, 2, 4, 7, and 24 h relative to the start of each LPS challenge. Plasma TSH, T4, T3, and rT3 were measured by radioimmunoassay. Liver D1 activity was measured in biopsy samples collected before the LPS1 (0 h) and 24 h after LPS2. Before the start of LPS1, HS decreased (P < 0.01 vs TN) plasma TSH (40%), T4 (45.4%), and T3 (25.9%), but did not affect rT3 concentrations. In TN steers, the LPS1 challenge decreased (P < 0.01 vs 0 h) plasma concentrations of TSH between 1 and 7 h and T4 and T3 at 7 and 24 h. In HS steers, plasma TSH concentrations were decreased at 2 h only (P < 0.05), whereas plasma T3 was decreased at 7 and 24 h (P < 0.01). Whereas plasma T4 concentrations were already depressed in HS steers at 0 h, LPS1 did not further affect the levels. Plasma rT3 concentrations

  5. Protecting Workers from Heat Stress

    MedlinePlus

    QUICK CARD TM Protecting Workers from Heat Stress Heat Illness Exposure to heat can cause illness and death. The most serious ... OSHA (6742) OSHA 3154 -06R 2014 QUICK CARD TM • Modify work schedules and arrange frequent rest periods ...

  6. Ensuring Reproduction at High Temperatures: The Heat Stress Response during Anther and Pollen Development

    PubMed Central

    Giorno, Filomena; Wolters-Arts, Mieke; Mariani, Celestina; Rieu, Ivo

    2013-01-01

    Sexual reproduction in flowering plants is very sensitive to environmental stresses, particularly to thermal insults which frequently occur when plants grow in field conditions in the warm season. Although abnormalities in both male and female reproductive organs due to high temperatures have been described in several crops, the failure to set fruits has mainly been attributed to the high sensitivity of developing anthers and pollen grains, particularly at certain developmental stages. A global view of the molecular mechanisms involved in the response to high temperatures in the male reproductive organs will be presented in this review. In addition, transcriptome and proteomic data, currently available, will be discussed in the light of physiological and metabolic changes occurring during anther and pollen development. A deep understanding of the molecular mechanisms involved in the stress response to high temperatures in flowers and, particularly, in the male reproductive organs will be a major step towards development of effective breeding strategies for high and stable production in crop plants. PMID:27137389

  7. Global Gene-Expression Analysis to Identify Differentially Expressed Genes Critical for the Heat Stress Response in Brassica rapa.

    PubMed

    Dong, Xiangshu; Yi, Hankuil; Lee, Jeongyeo; Nou, Ill-Sup; Han, Ching-Tack; Hur, Yoonkang

    2015-01-01

    Genome-wide dissection of the heat stress response (HSR) is necessary to overcome problems in crop production caused by global warming. To identify HSR genes, we profiled gene expression in two Chinese cabbage inbred lines with different thermotolerances, Chiifu and Kenshin. Many genes exhibited >2-fold changes in expression upon exposure to 0.5- 4 h at 45°C (high temperature, HT): 5.2% (2,142 genes) in Chiifu and 3.7% (1,535 genes) in Kenshin. The most enriched GO (Gene Ontology) items included 'response to heat', 'response to reactive oxygen species (ROS)', 'response to temperature stimulus', 'response to abiotic stimulus', and 'MAPKKK cascade'. In both lines, the genes most highly induced by HT encoded small heat shock proteins (Hsps) and heat shock factor (Hsf)-like proteins such as HsfB2A (Bra029292), whereas high-molecular weight Hsps were constitutively expressed. Other upstream HSR components were also up-regulated: ROS-scavenging genes like glutathione peroxidase 2 (BrGPX2, Bra022853), protein kinases, and phosphatases. Among heat stress (HS) marker genes in Arabidopsis, only exportin 1A (XPO1A) (Bra008580, Bra006382) can be applied to B. rapa for basal thermotolerance (BT) and short-term acquired thermotolerance (SAT) gene. CYP707A3 (Bra025083, Bra021965), which is involved in the dehydration response in Arabidopsis, was associated with membrane leakage in both lines following HS. Although many transcription factors (TF) genes, including DREB2A (Bra005852), were involved in HS tolerance in both lines, Bra024224 (MYB41) and Bra021735 (a bZIP/AIR1 [Anthocyanin-Impaired-Response-1]) were specific to Kenshin. Several candidate TFs involved in thermotolerance were confirmed as HSR genes by real-time PCR, and these assignments were further supported by promoter analysis. Although some of our findings are similar to those obtained using other plant species, clear differences in Brassica rapa reveal a distinct HSR in this species. Our data could also provide a

  8. Growth, immune, antioxidant, and bone responses of heat stress-exposed broilers fed diets supplemented with tomato pomace

    NASA Astrophysics Data System (ADS)

    Hosseini-Vashan, S. J.; Golian, A.; Yaghobfar, A.

    2015-11-01

    A study was conducted to investigate the effects of supplementation of dried tomato pomace (DTP) on growth performance, relative weights of viscera, serum biological parameters, antioxidant status, immune response, and bone composition of broilers exposed to a high ambient temperature. A total of 352 one-day-old male broiler chickens were randomly divided into four groups consisting of four replicates with 22 birds each. One group was reared under the thermoneutral zone and fed a corn-soybean meal basal diet. The other three groups were subjected to a cyclic heat stress from 29 to 42 days of age (34 ± 1 °C, 55 % RH, 5 h/day). These birds were fed corn-soybean meal basal diet or the same diet supplemented with 3 % DTP (420 mg lycopene/kg diet) or 5 % (708 mg lycopene/kg diet) of DTP. Blood samples were collected on days 28 and 42, and the birds were slaughtered at the same times. Supplementation of 5 % of DTP increased body weight and production index and decreased feed conversion ratio during 1-28 days of age. On day 28, the broilers supplemented with 5 % DTP had lower serum triglycerides and higher high-density lipoprotein (HDL) cholesterol concentration than those on the other dietary treatments. The activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were higher and the concentration of malondialdehyde (MDA) was lower in the broilers fed 5 % TP than those of the broilers fed other diets at 28 days of age. The effects of heat stress (HS) were impaired body weight, enhanced serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lipase, and MDA concentration while reducing the activities of GPx and SOD. Dried tomato pomace supplementation did not influence growth performance under HS but ameliorated the negative effects of HS on the serum enzyme activities, GPx activity, and lipid peroxidation. Heat stress did not change the relative weights of the lymphoid organs but reduced the total and IgG titers

  9. Growth, immune, antioxidant, and bone responses of heat stress-exposed broilers fed diets supplemented with tomato pomace

    NASA Astrophysics Data System (ADS)

    Hosseini-Vashan, S. J.; Golian, A.; Yaghobfar, A.

    2016-08-01

    A study was conducted to investigate the effects of supplementation of dried tomato pomace (DTP) on growth performance, relative weights of viscera, serum biological parameters, antioxidant status, immune response, and bone composition of broilers exposed to a high ambient temperature. A total of 352 one-day-old male broiler chickens were randomly divided into four groups consisting of four replicates with 22 birds each. One group was reared under the thermoneutral zone and fed a corn-soybean meal basal diet. The other three groups were subjected to a cyclic heat stress from 29 to 42 days of age (34 ± 1 °C, 55 % RH, 5 h/day). These birds were fed corn-soybean meal basal diet or the same diet supplemented with 3 % DTP (420 mg lycopene/kg diet) or 5 % (708 mg lycopene/kg diet) of DTP. Blood samples were collected on days 28 and 42, and the birds were slaughtered at the same times. Supplementation of 5 % of DTP increased body weight and production index and decreased feed conversion ratio during 1-28 days of age. On day 28, the broilers supplemented with 5 % DTP had lower serum triglycerides and higher high-density lipoprotein (HDL) cholesterol concentration than those on the other dietary treatments. The activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were higher and the concentration of malondialdehyde (MDA) was lower in the broilers fed 5 % TP than those of the broilers fed other diets at 28 days of age. The effects of heat stress (HS) were impaired body weight, enhanced serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lipase, and MDA concentration while reducing the activities of GPx and SOD. Dried tomato pomace supplementation did not influence growth performance under HS but ameliorated the negative effects of HS on the serum enzyme activities, GPx activity, and lipid peroxidation. Heat stress did not change the relative weights of the lymphoid organs but reduced the total and IgG titers

  10. Application of a Nonlinear Model to Transcript Levels of Upregulated Stress Response Gene ibpA in Stationary-Phase Salmonella enterica Subjected to Sublethal Heat Stress.

    PubMed

    Carroll, Laura M; Bergholz, Teresa M; Hildebrandt, Ian M; Marks, Bradley P

    2016-07-01

    Sublethal heating, which can occur during slow cooking of meat products, is known to induce increased thermal resistance in Salmonella. However, very few studies have addressed the kinetics of this response. Although several recent studies have reported improved thermal inactivation models that include the effect of prior sublethal history on subsequent thermal resistance, none of these models were based on cellular-level responses to sublethal thermal stress. The goal of this study was to determine whether a nonlinear model could accurately portray the response of Salmonella to heat stress induced by prolonged exposure to sublethal temperatures. To accomplish this, stationary-phase Salmonella Montevideo cultures were subjected to various heating profiles (held at either 40 or 45°C for 0, 5, 10, 15, 30, 60, 90, 180, or 240 min) using a PCR thermal cycler. Differential plating on selective and nonselective media was used to confirm the presence of cellular injury. Reverse transcription quantitative PCR was used to screen the transcript levels of six heat stress-related genes to find candidate genes for nonlinear modeling. Injury was detected in populations of Salmonella held at 45°C for 30, 60, and 90 min and at 40°C for 0, 5, and 90 min (P < 0.05), whereas no significant injury was found at 180 and 240 min (P > 0.05). The transcript levels of ibpA, which codes for a small heat shock protein associated with the ClpB and DnaK-DnaJ-GrpE chaperone systems, showed the greatest increase relative to the transcript levels at 0 min, which was significant at 5, 10, 15, 30, 60, 90, and 180 min at 45°C and at 5, 10, 15, 30, 60, and 90 min at 40°C (P < 0.05). Using ibpA transcript levels as an indicator of adaptation to thermal stress, a nonlinear model for sublethal injury is proposed. The use of variables indicating the physiological state of the pathogen during stress has the potential to increase the accuracy of thermal inactivation models that must account for

  11. Heat shock factors in carrot: genome-wide identification, classification, and expression profiles response to abiotic stress.

    PubMed

    Huang, Ying; Li, Meng-Yao; Wang, Feng; Xu, Zhi-Sheng; Huang, Wei; Wang, Guang-Long; Ma, Jing; Xiong, Ai-Sheng

    2015-05-01

    Heat shock factors (HSFs) play key roles in the response to abiotic stress in eukaryotes. In this study, 35 DcHSFs were identified from carrot (Daucus carota L.) based on the carrot genome database. All 35 DcHSFs were divided into three classes (A, B, and C) according to the structure and phylogenetic relationships of four different plants, namely, Arabidopsis thaliana, Vitis vinifera, Brassica rapa, and Oryza sativa. Comparative analysis of algae, gymnosperms, and angiosperms indicated that the numbers of HSF transcription factors were related to the plant's evolution. The expression profiles of five DcHsf genes (DcHsf 01, DcHsf 02, DcHsf 09, DcHsf 10, and DcHsf 16), which selected from each subfamily (A, B, and C), were detected by quantitative real-time PCR under abiotic stresses (cold, heat, high salinity, and drought) in two carrot cultivars, D. carota L. cvs. Kurodagosun and Junchuanhong. The expression levels of DcHsfs were markedly increased by heat stress, except that of DcHsf 10, which was down regulated. The expression profiles of different DcHsfs in the same class also differed under various stress treatments. The expression profiles of these DcHsfs were also different in tissues of two carrot cultivars. This study is the first to identify and characterize the DcHSF family transcription factors in plants of Apiaceae using whole-genome analysis. The results of this study provide an in-depth understanding of the DcHSF family transcription factors' structure, function, and evolution in carrot. PMID:25403331

  12. Global Gene-Expression Analysis to Identify Differentially Expressed Genes Critical for the Heat Stress Response in Brassica rapa

    PubMed Central

    Dong, Xiangshu; Yi, Hankuil; Lee, Jeongyeo; Nou, Ill-Sup; Han, Ching-Tack; Hur, Yoonkang

    2015-01-01

    Genome-wide dissection of the heat stress response (HSR) is necessary to overcome problems in crop production caused by global warming. To identify HSR genes, we profiled gene expression in two Chinese cabbage inbred lines with different thermotolerances, Chiifu and Kenshin. Many genes exhibited >2-fold changes in expression upon exposure to 0.5– 4 h at 45°C (high temperature, HT): 5.2% (2,142 genes) in Chiifu and 3.7% (1,535 genes) in Kenshin. The most enriched GO (Gene Ontology) items included ‘response to heat’, ‘response to reactive oxygen species (ROS)’, ‘response to temperature stimulus’, ‘response to abiotic stimulus’, and ‘MAPKKK cascade’. In both lines, the genes most highly induced by HT encoded small heat shock proteins (Hsps) and heat shock factor (Hsf)-like proteins such as HsfB2A (Bra029292), whereas high-molecular weight Hsps were constitutively expressed. Other upstream HSR components were also up-regulated: ROS-scavenging genes like glutathione peroxidase 2 (BrGPX2, Bra022853), protein kinases, and phosphatases. Among heat stress (HS) marker genes in Arabidopsis, only exportin 1A (XPO1A) (Bra008580, Bra006382) can be applied to B. rapa for basal thermotolerance (BT) and short-term acquired thermotolerance (SAT) gene. CYP707A3 (Bra025083, Bra021965), which is involved in the dehydration response in Arabidopsis, was associated with membrane leakage in both lines following HS. Although many transcription factors (TF) genes, including DREB2A (Bra005852), were involved in HS tolerance in both lines, Bra024224 (MYB41) and Bra021735 (a bZIP/AIR1 [Anthocyanin-Impaired-Response-1]) were specific to Kenshin. Several candidate TFs involved in thermotolerance were confirmed as HSR genes by real-time PCR, and these assignments were further supported by promoter analysis. Although some of our findings are similar to those obtained using other plant species, clear differences in Brassica rapa reveal a distinct HSR in this species. Our data

  13. Stress Responses of Small Heat Shock Protein Genes in Lepidoptera Point to Limited Conservation of Function across Phylogeny

    PubMed Central

    Zhang, Bo; Zheng, Jincheng; Peng, Yu; Liu, Xiaoxia; Hoffmann, Ary A.; Ma, Chun-Sen

    2015-01-01

    The small heat shock protein (sHsp) family is thought to play an important role in protein refolding and signal transduction, and thereby protect organisms from stress. However little is known about sHsp function and conservation across phylogenies. In the current study, we provide a comprehensive assessment of small Hsp genes and their stress responses in the oriental fruit moth (OFM), Grapholita molesta. Fourteen small heat shock proteins of OFM clustered with related Hsps in other Lepidoptera despite a high level of variability among them, and in contrast to the highly conserved Hsp11.1. The only known lepidopteran sHsp ortholog (Hsp21.3) was consistently unaffected under thermal stress in Lepidoptera where it has been characterized. However the phylogenetic position of the sHsps within the Lepidoptera was not associated with conservation of induction patterns under thermal extremes or diapause. These findings suggest that the sHsps have evolved rapidly to develop new functions within the Lepidoptera. PMID:26196395

  14. Heat stress in pigs is accompanied by adipose tissue-specific responses that favor increased triglyceride storage.

    PubMed

    Qu, H; Yan, H; Lu, H; Donkin, S S; Ajuwon, K M

    2016-05-01

    Heat stress (HS) negatively affects all aspects of performance in pigs. Although certain tissue-specific responses in the liver, skeletal muscle, and intestine are known, there is paucity of information on responses within the adipose tissue. Therefore, the objective of this study was to delineate adipose tissue responses during HS in pigs. Thirty crossbred (Ossabaw × Duroc × Landrace) pigs were assigned to 3 treatments for 7 d. Treatments were 1) control and libitum fed (CON) with room temperature set at 20°C ± 1°C, 2) pair fed (PF) with room temperature as the CON treatment but pair fed to HS pigs, and 3) HS with room temperature 35°C ± 1°C and ad libitum access to feed. Compared with CON pigs, HS pigs had decreased feed intake and elevated skin temperature and respiration rate ( < 0.01). Blood urea nitrogen was higher ( = 0.01) in HS pigs compared with CON pigs only in males. In both subcutaneous and mesenteric adipose tissue, mRNA abundance of phosphoenolpyruvate carboxykinase (PCK1) was more elevated ( < 0.01) in HS groups compared with the CON and PF groups. Heat stress also caused increased heat shock protein 70 (HSP70; = 0.067) and CCAT/enhancer-binding homologous protein (CHOP) content ( < 0.05) in the mesenteric fat compared with the CON treatment. In conclusion, induction of PCK1 expression in adipose tissue by HS suggests elevated glyceroneogenesis might be involved in the increased fat storage in pigs under HS. PMID:27285686

  15. Heat Stress-Induced DNA Damage

    PubMed Central

    Kantidze, O.L.; Velichko, A.K.; Luzhin, A.V.; Razin, S.V.

    2016-01-01

    Although the heat-stress response has been extensively studied for decades, very little is known about its effects on nucleic acids and nucleic acid-associated processes. This is due to the fact that the research has focused on the study of heat shock proteins and factors (HSPs and HSFs), their involvement in the regulation of transcription, protein homeostasis, etc. Recently, there has been some progress in the study of heat stress effects on DNA integrity. In this review, we summarize and discuss well-known and potential mechanisms of formation of various heat stress-induced DNA damage. PMID:27437141

  16. Effect of mild heat stress and mild infection pressure on immune responses to an E. coli infection in chickens.

    PubMed

    Norup, L R; Jensen, K H; Jørgensen, E; Sørensen, P; Juul-Madsen, H R

    2008-02-01

    Outdoor or organic farming demands robust chickens that are able to combat common infections before they spread to the flock. Priming the immune system of the chickens early in life with micro-organisms that they will encounter later in life prepares chickens to a life in environments where they are subjected to a more natural level of infection pressure. Also, exposure to non-infectious stressful situations may prepare the immune system to combat infectious challenges. The present study investigated whether the immune system could be primed by applying small doses of infective material to the chicken flock or by exposure to short-term non-infectious stimulation, and whether the effect of those stimuli would depend on the genetic material chosen. The effect of the stimulations was examined on selected immunological variables in two chicken strains, using small amounts of manure and litter from other chickens or short-term heat stress, respectively. After 6 weeks of treatment, all chickens were subjected to an Escherichia coli infection and followed for another 3 weeks. Measures of body weight gain, chicken mannan-binding lectin (cMBL), percentage of CD4+ and MHCII+ lymphocytes, mean fluorescence intensity (m.f.i.) of CD4 on CD4+ cells and MHCII on MHCII+ cells and antibody titres to E. coli were taken. In conclusion, the chickens redistribute lymphocyte populations in peripheral blood in response to potentially infectious agents as well as to stressful non-infectious treatments. Responses to stress situations were dependent on the frequencies of stress exposures and on the chicken breed. This may reflect the superiority of one breed over another in adapting to treatments or in discriminating whether a treatment is harmless or dangerous. However, the differences did not influence the disease resistance to infection with a mixture of E. coli O2, O11 and O78 in the present study. PMID:22445020

  17. Aging augments mitochondrial susceptibility to heat stress

    PubMed Central

    Haak, Jodie L.; Buettner, Garry R.; Spitz, Douglas R.; Kregel, Kevin C.

    2009-01-01

    The pathophysiology of aging is accompanied by a decline in tolerance to environmental stress. While mitochondria are primary suspects in the etiology of aging, little is known about their ability to tolerate perturbations to homeostasis in older organisms. To investigate the role of mitochondria in the increased susceptibility to heat stress that accompanies aging, young and old Fischer 344 rats underwent a heat stress protocol known to elicit exaggerated cellular damage with aging. At either 2 or 24 h after heat stress, livers were removed from animals, and hepatic mitochondria were isolated. Electron microscopy revealed extensive morphological damage to mitochondria from young and, to a greater extent, old rats after heat stress. There was also a significant loss of cytochrome c from old, but not young, mitochondria and a persistent increase in 4-hydroxynonenal-modified proteins in old vs. young mitochondria exposed to heat stress. Electron paramagnetic resonance measurements of superoxide indicate greater superoxide production from mitochondria of old compared with young animals and suggest that mitochondrial integrity was altered during heat stress. The mitochondrial stress response, which functions to correct stress-induced damage to mitochondrial proteins, was also blunted in old rats. Delayed and reduced levels of heat shock protein 60 (Hsp60), the main inducible mitochondrial stress protein, were observed in old compared with young mitochondria after heat stress. Additionally, the amount of Hsp10 protein increased in young, but not old, rat liver mitochondria after hyperthermic challenge. Taken together, these data suggest that mitochondria in old animals are more vulnerable to incurring and less able to repair oxidative damage that occurs in response to a physiologically relevant heat stress. PMID:19144753

  18. Heat stress proteins in hypertension

    SciTech Connect

    Malo, D.; Tremblay, J.; Pang, S.C.; Schlager, G.; Hamet, P.

    1986-03-05

    It has been described that spontaneously hypertensive rats (SHR) are more sensitive to an acute environmental heat stress and that cultured cardiomyocytes from neonatal SHR are demonstrated to be more thermosensitive. In addition, chronically heat exposed spontaneously hypertensive mice leads to a decrease of blood pressure in these animals. Heat shock is known to induce the synthesis of a new set of proteins (HSP) in every cell tested. This ubiquitous response seems to be involved in the induction of a thermotolerant state. The synthesis of 70K HSP was observed in lymphocytes isolated from the spleen of chronically heated mice. They used lymphocytes, previously isolated on a ficoll gradient, to evaluate the HSP induction in normotensive (WKY) and hypertensive (SHR) rats. The heat shock was induced by exposing the lymphocytes at 46/sup 0/C during 5 min in a hot water bath. The cells were then labeled with (/sup 75/Se)-methionine, washed, homogenized and separated on 5-30% SDS-polyacrylamide gel. Preliminary results suggest an abnormal pattern of induction of 70K and 90K HSP in hypertension. Heat sensitivity, thermotolerance and expression of HSP may, thus, be related to hypertension.

  19. Grape seed extract supplementation attenuates the heat stress-induced responses of jejunum epithelial cells in Simmental × Qinchuan steers.

    PubMed

    Li, Xiaomin; Yang, You; Liu, Shimin; Yang, Jing; Chen, Cheng; Sun, Zhihong

    2014-08-14

    Grape seed extract (GSE), a rich source of polyphenols, is reported to possess antioxidant, anti-inflammatory and immunomodulatory properties. The objective of the present study was to determine whether GSE could attenuate the heat stress-induced responses of jejunum epithelial cells (JEC) in cattle. The JEC of a steer (Simmental × Qinchuan) were exposed to heat stress for 2 h in the absence (0 μg/ml) or presence (10, 20, 40 and 80 μg/ml) of GSE in the culture medium. When cultured at 40°C, JEC supplemented with GSE exhibited increased glutathione peroxidase activity (P= 0·04), viability (P= 0·004), and mRNA expression of epidermal growth factor (EGF; P= 0·03) and EGF receptor (EGFR; P = 0·01). Under the same conditions, the cells exhibited decreased mRNA expression of IL-8 (P= 0·01) and TNF-α (P= 0·03) and decreased protein concentrations of IL-1β (P= 0·02), Toll-like receptor 4 (TLR4; P= 0·04) and heat shock protein 70 (HSP70; P< 0·001). When cultured at 43°C, JEC supplemented with GSE exhibited increased catalase activity (P= 0·04), viability (P< 0·001), and mRNA expression of EGF (P< 0·001) and EGFR (P< 0·001) and decreased protein concentrations of IL-1β (P< 0·001), TLR4 (P= 0·03) and HSP70 (P< 0·001), as well as mRNA expression of IL-8 (P< 0·001), TLR4 (P= 0·002) and TNF-α (P< 0·001). Temperature × GSE concentration interactions were also observed for the concentrations of IL-1β (P< 0·001), IL-8 (P< 0·001), TNF-α (P= 0·01) and HSP70 (P= 0·04) and viability (P< 0·001) of JEC. The results of the present study indicate that GSE can attenuate the responses of JEC induced by heat stress within a certain range of temperatures. PMID:24846452

  20. Acetylsalicylic acid does not alter thermo-effector responses during mild whole-body passive heat stress in young men.

    PubMed

    Carter, Stephen J; Herron, Robert L; Akers, S Zeb; Bishop, Phillip A

    2015-06-01

    Acetylsalicylic acid (ASA), aspirin, exerts potent systemic effects that may interfere with normal thermo-effector responses. We investigated the influence of commonly ingested ASA doses on measures of skin blood flow (SkBF) and local sweat rate (SR) during whole-body, passive heat stress. Seven male participants completed counter-balanced trials to compare ASA treatments (single dose 325 mg or 4 consecutive days 81 mg (4-d 81 mg)) to control (no ASA). Laser-Doppler flowmetry provided an index of SkBF. A ventilated capsule measured local sweat rate via capacitance hygrometry. Mean body temperature ([Formula: see text]) was increased by 1 °C above baseline using a water-perfused suit. [Formula: see text] was similar at the onset of cutaneous vasodilation among trials. Cutaneous vascular conductance, expressed as a percentage change from baseline, was not different among trials. Additionally, [Formula: see text] at the onset of local SR and SR sensitivity did not differ among trials. While ASA has previously been shown to influence SkBF during heat stress, it is possible our cohort's relatively young age may have contributed to our dissimilar results. PMID:25697227

  1. Heat Stress Effects on Growing-Finishing Swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the factors that create heat stress, the response of the animals while under heat stress, and the signs of heat-stressed swine are essential to making rational decisions for the selection, design, and management of their environments. Heat stressors include combinations of environment...

  2. Cardiorespiratory control and cytokine profile in response to heat stress, hypoxia, and lipopolysaccharide (LPS) exposure during early neonatal period.

    PubMed

    McDonald, Fiona B; Chandrasekharan, Kumaran; Wilson, Richard J A; Hasan, Shabih U

    2016-02-01

    Sudden infant death syndrome (SIDS) is one of the most common causes of postneonatal infant mortality in the developed world. An insufficient cardiorespiratory response to multiple environmental stressors (such as prone sleeping positioning, overwrapping, and infection), during a critical period of development in a vulnerable infant, may result in SIDS. However, the effect of multiple risk factors on cardiorespiratory responses has rarely been tested experimentally. Therefore, this study aimed to quantify the independent and possible interactive effects of infection, hyperthermia, and hypoxia on cardiorespiratory control in rats during the neonatal period. We hypothesized that lipopolysaccharide (LPS) administration will negatively impact cardiorespiratory responses to increased ambient temperature and hypoxia in neonatal rats. Sprague-Dawley neonatal rat pups were studied at postnatal day 6-8. Rats were examined at an ambient temperature of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 μg/kg) treatments. Cardiorespiratory and thermal responses were recorded and analyzed before, during, and after a hypoxic exposure (10% O2). Serum samples were taken at the end of each experiment to measure cytokine concentrations. LPS significantly increased cytokine concentrations (such as TNFα, IL-1β, MCP-1, and IL-10) compared to control. Our results do not support a three-way interaction between experimental factors on cardiorespiratory control. However, independently, heat stress decreased minute ventilation during normoxia and increased the hypoxic ventilatory response. Furthermore, LPS decreased hypoxia-induced tachycardia. Herein, we provide an extensive serum cytokine profile under various experimental conditions and new evidence that neonatal cardiorespiratory responses are adversely affected by dual interactions of environmental stress factors. PMID:26811056

  3. Histone acetyltransferase GCN5 is essential for heat stress-responsive gene activation and thermotolerance in Arabidopsis.

    PubMed

    Hu, Zhaorong; Song, Na; Zheng, Mei; Liu, Xinye; Liu, Zhenshan; Xing, Jiewen; Ma, Junhua; Guo, Weiwei; Yao, Yingyin; Peng, Huiru; Xin, Mingming; Zhou, Dao-Xiu; Ni, Zhongfu; Sun, Qixin

    2015-12-01

    Exposure to temperatures exceeding the normal optimum levels, or heat stress (HS), constitutes an environmental disruption for plants, resulting in severe growth and development retardation. Here we show that loss of function of the Arabidopsis histone acetyltransferase GCN5 results in serious defects in terms of thermotolerance, and considerably impairs the transcriptional activation of HS-responsive genes. Notably, expression of several key regulators such as the HS transcription factors HSFA2 and HSFA3, Multiprotein Bridging Factor 1c (MBF1c) and UV-HYPERSENSITIVE 6 (UVH6) is down-regulated in the gcn5 mutant under HS compared with the wild-type. Chromatin immunoprecipitation (ChIP) assays indicated that GCN5 protein is enriched at the promoter regions of HSFA3 and UVH6 genes, but not in HSFA2 and MBF1c, and that GCN5 facilitates H3K9 and H3K14 acetylation, which are associated with HSFA3 and UVH6 activation under HS. Moreover, constitutive expression of UVH6 in the gcn5 mutant partially restores heat tolerance. Taken together, our data indicate that GCN5 plays a key role in the preservation of thermotolerance via versatile regulation in Arabidopsis. In addition, expression of the wheat TaGCN5 gene re-establishes heat tolerance in Arabidopsis gcn5 mutant plants, suggesting that GCN5-mediated thermotolerance may be conserved between Arabidopsis and wheat. PMID:26576681

  4. Growth, immune, antioxidant, and bone responses of heat stress-exposed broilers fed diets supplemented with tomato pomace.

    PubMed

    Hosseini-Vashan, S J; Golian, A; Yaghobfar, A

    2016-08-01

    A study was conducted to investigate the effects of supplementation of dried tomato pomace (DTP) on growth performance, relative weights of viscera, serum biological parameters, antioxidant status, immune response, and bone composition of broilers exposed to a high ambient temperature. A total of 352 one-day-old male broiler chickens were randomly divided into four groups consisting of four replicates with 22 birds each. One group was reared under the thermoneutral zone and fed a corn-soybean meal basal diet. The other three groups were subjected to a cyclic heat stress from 29 to 42 days of age (34 ± 1 °C, 55 % RH, 5 h/day). These birds were fed corn-soybean meal basal diet or the same diet supplemented with 3 % DTP (420 mg lycopene/kg diet) or 5 % (708 mg lycopene/kg diet) of DTP. Blood samples were collected on days 28 and 42, and the birds were slaughtered at the same times. Supplementation of 5 % of DTP increased body weight and production index and decreased feed conversion ratio during 1-28 days of age. On day 28, the broilers supplemented with 5 % DTP had lower serum triglycerides and higher high-density lipoprotein (HDL) cholesterol concentration than those on the other dietary treatments. The activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were higher and the concentration of malondialdehyde (MDA) was lower in the broilers fed 5 % TP than those of the broilers fed other diets at 28 days of age. The effects of heat stress (HS) were impaired body weight, enhanced serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lipase, and MDA concentration while reducing the activities of GPx and SOD. Dried tomato pomace supplementation did not influence growth performance under HS but ameliorated the negative effects of HS on the serum enzyme activities, GPx activity, and lipid peroxidation. Heat stress did not change the relative weights of the lymphoid organs but reduced the

  5. Expression Profiles of the Heat Shock Protein 70 Gene in Response to Heat Stress in Agrotis c-nigrum (Lepidoptera: Noctuidae)

    PubMed Central

    Wang, Ling; Yang, Shuai; Zhao, Kuijun; Han, Lanlan

    2015-01-01

    Heat shock proteins (HSPs) are molecular chaperones, and their overexpression enhances the survivability and stress tolerance of the cell. To understand the characteristics of HSP70 in Agrotis c-nigrum Linnaeus larvae, the coding sequence of this protein was cloned, and the effect of heat stress on transcription and protein properties was assessed. The obtained cDNA sequence of HSP70 was 2,213 bp, which contained an ORF of 1,965 bp and encoded 654 amino acid residues. Isolated HSP70 cDNA demonstrated more than 80% identity with the sequences of other known insect HSP70s. Next, HSP70 was expressed in Escherichia coli BL21 (DE3) cells and identified using SDS-PAGE and western blotting analyses. In addition, anti-HSP70-specific antisera were prepared using a recombinant HSP70 protein, and the results showed that this antisera was very specific to AcHSP70. Real-time quantitative polymerase chain reaction detected the relative transcription of the HSP70 gene in larvae and the transcription of A. c-nigrum in response to high temperatures. Induction of HSP70 was up-regulated to peak expression at 36°C. PMID:25688087

  6. Heat stress in feedlot cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress in feedlot cattle is a common summer time occurrence in cattle-producing parts of the world (United States, Australia, Brazil, etc.). The impact of heat stress on feedlot animals is quite varied--from little to no effect in a brief exposure, to causing reductions in feed intake, growth,...

  7. Tuber Water and Pressure Potentials Decrease and Sucrose Contents Increase in Response to Moderate Drought and Heat Stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental stress during the growing season can reduce the quality of stored Solanum tuberosum (potato) tubers. Sugar end defect is a serious quality concern for growers and processors of russet potatoes that is initiated by drought or heat stress. Changes in tuber water potential and tuber compo...

  8. Resveratrol induces antioxidant and heat shock protein mRNA expression in response to heat stress in black-boned chickens.

    PubMed

    Liu, L L; He, J H; Xie, H B; Yang, Y S; Li, J C; Zou, Y

    2014-01-01

    This study investigated the effects of dietary resveratrol at 0, 200, 400, or 600 mg/kg of diet on the performance, immune organ growth index, serum parameters, and expression levels of heat shock protein (Hsp) 27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius, thymus, and spleen of 42-d-old female black-boned chickens exposed to heat stress at 37 ± 2°C for 15 d. The results showed that heat stress reduced daily feed intake and BW gain; decreased serum glutathione (GSH), growth hormone, and insulin-like growth factor-1 levels; and inhibited GSH peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities compared with birds subjected to thermo-neutral circumstances. Chickens that were fed diets supplemented with resveratrol exhibited a linear increase in feed intake and BW gain (P < 0.001); serum GSH, growth hormone, and insulin-like growth factor-1 levels (P ≤ 0.01); and GSH-Px, SOD, and CAT activities (P < 0.001) compared with chickens that were fed diets without resveratrol during heat stress. In contrast, serum malonaldehyde concentrations were decreased (P < 0.001) in the chickens fed a resveratrol-supplemented diet. Heat stress also reduced (P < 0.05) the growth index of the bursa of Fabricus and spleen; however, it had no effect on the growth index of the thymus. The growth index of the bursa of Fabricius and spleen increased (P < 0.05) upon heat stress and coincided with an increase in supplemental resveratrol levels. The expression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen were increased (P < 0.01), but those of Hsp27 and Hsp90 mRNA in thymus were decreased (P < 0.01) under heat stress compared with no heat stress. Resveratrol attenuated the heat stress-induced overexpression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen and increased the low expression of Hsp27 and Hsp90 mRNA in thymus upon heat stress. The results suggest that supplemental resveratrol improves growth performance

  9. Metabolic Response to Heat Stress in Late-Pregnant and Early Lactation Dairy Cows: Implications to Liver-Muscle Crosstalk

    PubMed Central

    Eslamizad, Mehdi; Weitzel, Joachim; Kuhla, Björn

    2016-01-01

    Climate changes lead to rising temperatures during summer periods and dramatic economic losses in dairy production. Modern high-yielding dairy cows experience severe metabolic stress during the transition period between late gestation and early lactation to meet the high energy and nutrient requirements of the fetus or the mammary gland, and additional thermal stress during this time has adverse implications on metabolism and welfare. The mechanisms enabling metabolic adaptation to heat apart from the decline in feed intake and milk yield are not fully elucidated yet. To distinguish between feed intake and heat stress related effects, German Holstein dairy cows were first kept at thermoneutral conditions at 15°C followed by exposure to heat-stressed (HS) at 28°C or pair-feeding (PF) at 15°C for 6 days; in late-pregnancy and again in early lactation. Liver and muscle biopsies and plasma samples were taken to assess major metabolic pathway regulation using real-time PCR and Western Blot. The results indicate that during heat stress, late pregnant cows activate Cahill but reduce Cori cycling, prevent increase in skeletal muscle fatty acid oxidation, and utilize increased amounts of pyruvate for gluconeogenesis, without altering ureagenesis despite reduced plane of nutrition. These homeorhetic adaptations are employed to reduce endogenous heat production while diverting amino acids to the growing fetus. Metabolic adaptation to heat stress in early lactation involves increased long-chain fatty acid degradation in muscle peroxisomes, allowance for muscle glucose utilization but diminished hepatic use of amino acid-derived pyruvate for gluconeogenesis and reduced peroxisomal fatty acid oxidation and ATP production in liver of HS compared to PF cows in early lactation. Consequently, metabolic adaptation to heat stress and reduced feed intake differ between late pregnancy and early lactation of dairy cows to maintain energy supply for fetus development or milk production

  10. Metabolic Response to Heat Stress in Late-Pregnant and Early Lactation Dairy Cows: Implications to Liver-Muscle Crosstalk.

    PubMed

    Koch, Franziska; Lamp, Ole; Eslamizad, Mehdi; Weitzel, Joachim; Kuhla, Björn

    2016-01-01

    Climate changes lead to rising temperatures during summer periods and dramatic economic losses in dairy production. Modern high-yielding dairy cows experience severe metabolic stress during the transition period between late gestation and early lactation to meet the high energy and nutrient requirements of the fetus or the mammary gland, and additional thermal stress during this time has adverse implications on metabolism and welfare. The mechanisms enabling metabolic adaptation to heat apart from the decline in feed intake and milk yield are not fully elucidated yet. To distinguish between feed intake and heat stress related effects, German Holstein dairy cows were first kept at thermoneutral conditions at 15°C followed by exposure to heat-stressed (HS) at 28°C or pair-feeding (PF) at 15°C for 6 days; in late-pregnancy and again in early lactation. Liver and muscle biopsies and plasma samples were taken to assess major metabolic pathway regulation using real-time PCR and Western Blot. The results indicate that during heat stress, late pregnant cows activate Cahill but reduce Cori cycling, prevent increase in skeletal muscle fatty acid oxidation, and utilize increased amounts of pyruvate for gluconeogenesis, without altering ureagenesis despite reduced plane of nutrition. These homeorhetic adaptations are employed to reduce endogenous heat production while diverting amino acids to the growing fetus. Metabolic adaptation to heat stress in early lactation involves increased long-chain fatty acid degradation in muscle peroxisomes, allowance for muscle glucose utilization but diminished hepatic use of amino acid-derived pyruvate for gluconeogenesis and reduced peroxisomal fatty acid oxidation and ATP production in liver of HS compared to PF cows in early lactation. Consequently, metabolic adaptation to heat stress and reduced feed intake differ between late pregnancy and early lactation of dairy cows to maintain energy supply for fetus development or milk production

  11. Interactions between 2-Cys peroxiredoxins and ascorbate in autophagosome formation during the heat stress response in Solanum lycopersicum

    PubMed Central

    Cheng, Fei; Yin, Ling-Ling; Zhou, Jie; Xia, Xiao-Jian; Shi, Kai; Yu, Jing-Quan; Zhou, Yan-Hong; Foyer, Christine Helen

    2016-01-01

    2-Cys peroxiredoxins (2-CPs) function in the removal of hydrogen peroxide and lipid peroxides but their precise roles in the induction of autophagy have not been characterized. Here we show that heat stress, which is known to induce oxidative stress, leads to the simultaneous accumulation of transcripts encoding 2-CPs and autophagy proteins, as well as autophagosomes, in tomato (Solanum lycopersicum) plants. Virus-induced gene silencing of the tomato peroxiredoxin genes 2-CP1, 2-CP2, and 2-CP1/2 resulted in an increased sensitivity of tomato plants to heat stress. Silencing 2-CP2 or 2-CP1/2 increased the levels of transcripts associated with ascorbate biosynthesis but had no effect on the glutathione pool in the absence of stress. However, the heat-induced accumulation of transcripts associated with the water-water cycle was compromised by the loss of 2-CP1/2 functions. The transcript levels of autophagy-related genes ATG5 and ATG7 were higher in plants with impaired 2-CP1/2 functions, and the formation of autophagosomes increased, together with an accumulation of oxidized and insoluble proteins. Silencing of ATG5 or ATG7 increased the levels of 2-CP transcripts and protein but decreased heat stress tolerance. These results demonstrate that 2-CPs fulfil a pivotal role in heat stress tolerance in tomato, via interactions with ascorbate-dependent pathways and autophagy. PMID:26834179

  12. Interactions between 2-Cys peroxiredoxins and ascorbate in autophagosome formation during the heat stress response in Solanum lycopersicum.

    PubMed

    Cheng, Fei; Yin, Ling-Ling; Zhou, Jie; Xia, Xiao-Jian; Shi, Kai; Yu, Jing-Quan; Zhou, Yan-Hong; Foyer, Christine Helen

    2016-03-01

    2-Cys peroxiredoxins (2-CPs) function in the removal of hydrogen peroxide and lipid peroxides but their precise roles in the induction of autophagy have not been characterized. Here we show that heat stress, which is known to induce oxidative stress, leads to the simultaneous accumulation of transcripts encoding 2-CPs and autophagy proteins, as well as autophagosomes, in tomato (Solanum lycopersicum) plants. Virus-induced gene silencing of the tomato peroxiredoxin genes 2-CP1, 2-CP2, and 2-CP1/2 resulted in an increased sensitivity of tomato plants to heat stress. Silencing 2-CP2 or 2-CP1/2 increased the levels of transcripts associated with ascorbate biosynthesis but had no effect on the glutathione pool in the absence of stress. However, the heat-induced accumulation of transcripts associated with the water-water cycle was compromised by the loss of 2-CP1/2 functions. The transcript levels of autophagy-related genes ATG5 and ATG7 were higher in plants with impaired 2-CP1/2 functions, and the formation of autophagosomes increased, together with an accumulation of oxidized and insoluble proteins. Silencing of ATG5 or ATG7 increased the levels of 2-CP transcripts and protein but decreased heat stress tolerance. These results demonstrate that 2-CPs fulfil a pivotal role in heat stress tolerance in tomato, via interactions with ascorbate-dependent pathways and autophagy. PMID:26834179

  13. Profiling of differential gene expression in the hypothalamus of broiler-type Taiwan country chickens in response to acute heat stress.

    PubMed

    Tu, Wei-Lin; Cheng, Chuen-Yu; Wang, Shih-Han; Tang, Pin-Chi; Chen, Chih-Feng; Chen, Hsin-Hsin; Lee, Yen-Pai; Chen, Shuen-Ei; Huang, San-Yuan

    2016-02-01

    Acute heat stress severely impacts poultry production. The hypothalamus acts as a crucial center to regulate body temperature, detect temperature changes, and modulate the autonomic nervous system and endocrine loop for heat retention and dissipation. The purpose of this study was to investigate global gene expression in the hypothalamus of broiler-type B strain Taiwan country chickens after acute heat stress. Twelve 30-week-old hens were allocated to four groups. Three heat-stressed groups were subjected to acute heat stress at 38 °C for 2 hours without recovery (H2R0), with 2 hours of recovery (H2R2), and with 6 hours of recovery (H2R6). The control hens were maintained at 25 °C. At the end, hypothalamus samples were collected for gene expression analysis. The results showed that 24, 11, and 25 genes were upregulated and 41, 15, and 42 genes were downregulated in H2R0, H2R2, and H2R6 treatments, respectively. The expressions of gonadotropin-releasing hormone 1 (GNRH1), heat shock 27-kDa protein 1 (HSPB1), neuropeptide Y (NPY), and heat shock protein 25 (HSP25) were upregulated at all recovery times after heat exposure. Conversely, the expression of TPH2 was downregulated at all recovery times. A gene ontology analysis showed that most of the differentially expressed genes were involved in biological processes including cellular processes, metabolic processes, localization, multicellular organismal processes, developmental processes, and biological regulation. A functional annotation analysis showed that the differentially expressed genes were related to the gene networks of responses to stress and reproductive functions. These differentially expressed genes might be essential and unique key factors in the heat stress response of the hypothalamus in chickens. PMID:26462659

  14. Expression analysis of ClpB/Hsp100 gene in faba bean (Vicia faba L.) plants in response to heat stress.

    PubMed

    Kumar, Ritesh; Singh, Amit Kumar; Lavania, Dhruv; Siddiqui, Manzer H; Al-Whaibi, Mohamed H; Grover, Anil

    2016-03-01

    Heat stress adversely affects the growth and yield of faba bean crop. Accumulation of ClpB/Hsp100 class of proteins is a critical parameter in induction of acquired heat stress tolerance in plants. Heat-induced expression of ClpB/Hsp100 genes has been noted in diverse plant species. Using primers complementary to soybean ClpB/Hsp100 gene, we analyzed the transcript expression profile of faba bean ClpB/Hsp100 gene in leaves of seedlings and flowering plants and in pollen grains. ClpB/Hsp100 protein accumulation profile was analyzed in leaves of faba bean seedlings using Arabidopsis thaliana cytoplasmic Hsp101 antibodies. The transcript and protein levels of faba bean ClpB/Hsp100 were significantly induced in response to heat stress. PMID:26981006

  15. The chloroplast Ndh complex mediates the dark reduction of the plastoquinone pool in response to heat stress in tobacco leaves.

    PubMed

    Sazanov, L A; Burrows, P A; Nixon, P J

    1998-06-01

    We have examined the effects of heat stress on electron transfer in the thylakoid membrane of an engineered plastid ndh deletion mutant, delta1, incapable of performing the Ndh-mediated reduction of the plastoquinone pool in the chloroplast. Upon heat stress in the dark, the rate of PSII-independent reduction of PSI after subsequent illumination by far-red light is dramatically enhanced in both delta1 and a wild-type control plant (WT). In contrast, in the dark, only the WT shows an increase in the reduction state of the plastoquinone pool. We conclude that the heat stress-induced reduction of the intersystem electron transport chain can be mediated by Ndh-independent pathways in the light but that in the dark the dominant pathway for reduction of the plastoquinone pool is catalysed by the Ndh complex. Our results therefore demonstrate a functional role for the Ndh complex in the dark. PMID:9657394

  16. Marine microbial symbiosis heats up: the phylogenetic and functional response of a sponge holobiont to thermal stress.

    PubMed

    Fan, Lu; Liu, Michael; Simister, Rachel; Webster, Nicole S; Thomas, Torsten

    2013-05-01

    Large-scale mortality of marine invertebrates is a major global concern for ocean ecosystems and many sessile, reef-building animals, such as sponges and corals, are experiencing significant declines through temperature-induced disease and bleaching. The health and survival of marine invertebrates is often dependent on intimate symbiotic associations with complex microbial communities, yet we have a very limited understanding of the detailed biology and ecology of both the host and the symbiont community in response to environmental stressors, such as elevated seawater temperatures. Here, we use the ecologically important sponge Rhopaloeides odorabile as a model to explore the changes in symbiosis during the development of temperature-induced necrosis. Expression profiling of the sponge host was examined in conjunction with the phylogenetic and functional structure and the expression profile of the symbiont community. Elevated temperature causes an immediate stress response in both the host and symbiont community, including reduced expression of functions that mediate their partnership. Disruption to nutritional interdependence and molecular interactions during early heat stress further destabilizes the holobiont, ultimately leading to the loss of archetypal sponge symbionts and the introduction of new microorganisms that have functional and expression profiles consistent with a scavenging lifestyle, a lack virulence functions and a high growth rate. Previous models have postulated various mechanisms of mortality and disease in marine invertebrates. Our study suggests that interruption of symbiotic interactions is a major determinant for mortality in marine sessile invertebrates. High symbiont specialization and low functional redundancy, thus make these holobionts extremely vulnerable to environmental perturbations, including climate change. PMID:23283017

  17. Marine microbial symbiosis heats up: the phylogenetic and functional response of a sponge holobiont to thermal stress

    PubMed Central

    Fan, Lu; Liu, Michael; Simister, Rachel; Webster, Nicole S; Thomas, Torsten

    2013-01-01

    Large-scale mortality of marine invertebrates is a major global concern for ocean ecosystems and many sessile, reef-building animals, such as sponges and corals, are experiencing significant declines through temperature-induced disease and bleaching. The health and survival of marine invertebrates is often dependent on intimate symbiotic associations with complex microbial communities, yet we have a very limited understanding of the detailed biology and ecology of both the host and the symbiont community in response to environmental stressors, such as elevated seawater temperatures. Here, we use the ecologically important sponge Rhopaloeides odorabile as a model to explore the changes in symbiosis during the development of temperature-induced necrosis. Expression profiling of the sponge host was examined in conjunction with the phylogenetic and functional structure and the expression profile of the symbiont community. Elevated temperature causes an immediate stress response in both the host and symbiont community, including reduced expression of functions that mediate their partnership. Disruption to nutritional interdependence and molecular interactions during early heat stress further destabilizes the holobiont, ultimately leading to the loss of archetypal sponge symbionts and the introduction of new microorganisms that have functional and expression profiles consistent with a scavenging lifestyle, a lack virulence functions and a high growth rate. Previous models have postulated various mechanisms of mortality and disease in marine invertebrates. Our study suggests that interruption of symbiotic interactions is a major determinant for mortality in marine sessile invertebrates. High symbiont specialization and low functional redundancy, thus make these holobionts extremely vulnerable to environmental perturbations, including climate change. PMID:23283017

  18. AsHSP17, a creeping bentgrass small heat shock protein modulates plant photosynthesis and ABA-dependent and independent signalling to attenuate plant response to abiotic stress.

    PubMed

    Sun, Xinbo; Sun, Chunyu; Li, Zhigang; Hu, Qian; Han, Liebao; Luo, Hong

    2016-06-01

    Heat shock proteins (HSPs) are molecular chaperones that accumulate in response to heat and other abiotic stressors. Small HSPs (sHSPs) belong to the most ubiquitous HSP subgroup with molecular weights ranging from 12 to 42 kDa. We have cloned a new sHSP gene, AsHSP17 from creeping bentgrass (Agrostis stolonifera) and studied its role in plant response to environmental stress. AsHSP17 encodes a protein of 17 kDa. Its expression was strongly induced by heat in both leaf and root tissues, and by salt and abscisic acid (ABA) in roots. Transgenic Arabidopsis plants constitutively expressing AsHSP17 exhibited enhanced sensitivity to heat and salt stress accompanied by reduced leaf chlorophyll content and decreased photosynthesis under both normal and stressed conditions compared to wild type. Overexpression of AsHSP17 also led to hypersensitivity to exogenous ABA and salinity during germination and post-germinative growth. Gene expression analysis indicated that AsHSP17 modulates expression of photosynthesis-related genes and regulates ABA biosynthesis, metabolism and ABA signalling as well as ABA-independent stress signalling. Our results suggest that AsHSP17 may function as a protein chaperone to negatively regulate plant responses to adverse environmental stresses through modulating photosynthesis and ABA-dependent and independent signalling pathways. PMID:26610288

  19. Thermal stress and the heat shock response in embryonic and young of the year juvenile lake whitefish.

    PubMed

    Stefanovic, Daniel I; Manzon, Lori A; McDougall, Chance S; Boreham, Douglas R; Somers, Christopher M; Wilson, Joanna Y; Manzon, Richard G

    2016-03-01

    We investigated the effects of thermal stress on embryonic (fin flutter, vitelline circulation stage) and young of the year (YOY) juvenile lake whitefish by characterizing the kinetics of the heat shock response (HSR). Lake whitefish were subjected to one of three different heat shock (HS) temperatures (3, 6, or 9°C above control) for six different lengths of time (0.25, 0.50, 1, 2, 3, or 4h) followed by a 2h recovery period at the control temperature of 2°C or 14°C for embryos and YOY juveniles, respectively. The duration of the HSR was examined by allowing the fish to recover for 1, 2, 4, 8, 12, 16, 24, 36, or 48h following a 2h HS. In embryos, at the fin flutter stage, only hsp70 mRNA levels were upregulated in response to the various HS treatments. By comparison, all three typically inducible hsps, hsp90α, hsp70 and hsp47, were upregulated in the YOY juveniles. In both instances the HSR was long lasting, but much more so in embryos where hsp70 mRNA levels continued to increase for 48h after a 2h HS and remained significantly higher than untreated controls. Collectively our data indicate that both embryo and YOY juvenile lake whitefish have a robust HSR which permits them to survive a 4h, 9°C HS. Moreover, both life history stages are capable of triggering a HSR following a moderate 3°C HS which is likely an important protective mechanism against environmental stressors during embryogenesis and early life history stages of lake whitefish. PMID:26658267

  20. Protective Response Mechanisms to Heat Stress in Interaction with High [CO2] Conditions in Coffea spp.

    PubMed Central

    Martins, Madlles Q.; Rodrigues, Weverton P.; Fortunato, Ana S.; Leitão, António E.; Rodrigues, Ana P.; Pais, Isabel P.; Martins, Lima D.; Silva, Maria J.; Reboredo, Fernando H.; Partelli, Fábio L.; Campostrini, Eliemar; Tomaz, Marcelo A.; Scotti-Campos, Paula; Ribeiro-Barros, Ana I.; Lidon, Fernando J. C.; DaMatta, Fábio M.; Ramalho, José C.

    2016-01-01

    Modeling studies have predicted that coffee crop will be endangered by future global warming, but recent reports highlighted that high [CO2] can mitigate heat impacts on coffee. This work aimed at identifying heat protective mechanisms promoted by CO2 in Coffea arabica (cv. Icatu and IPR108) and Coffea canephora cv. Conilon CL153. Plants were grown at 25/20°C (day/night), under 380 or 700 μL CO2 L−1, and then gradually submitted to 31/25, 37/30, and 42/34°C. Relevant heat tolerance up to 37/30°C for both [CO2] and all coffee genotypes was observed, likely supported by the maintenance or increase of the pools of several protective molecules (neoxanthin, lutein, carotenes, α-tocopherol, HSP70, raffinose), activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), and the upregulated expression of some genes (ELIP, Chaperonin 20). However, at 42/34°C a tolerance threshold was reached, mostly in the 380-plants and Icatu. Adjustments in raffinose, lutein, β-carotene, α-tocopherol and HSP70 pools, and the upregulated expression of genes related to protective (ELIPS, HSP70, Chape 20, and 60) and antioxidant (CAT, CuSOD2, APX Cyt, APX Chl) proteins were largely driven by temperature. However, enhanced [CO2] maintained higher activities of GR (Icatu) and CAT (Icatu and IPR108), kept (or even increased) the Cu,Zn-SOD, APX, and CAT activities, and promoted a greater upregulation of those enzyme genes, as well as those related to HSP70, ELIPs, Chaperonins in CL153, and Icatu. These changes likely favored the maintenance of reactive oxygen species (ROS) at controlled levels and contributed to mitigate of photosystem II photoinhibition at the highest temperature. Overall, our results highlighted the important role of enhanced [CO2] on the coffee crop acclimation and sustainability under predicted future global warming scenarios. PMID:27446174

  1. Protective Response Mechanisms to Heat Stress in Interaction with High [CO2] Conditions in Coffea spp.

    PubMed

    Martins, Madlles Q; Rodrigues, Weverton P; Fortunato, Ana S; Leitão, António E; Rodrigues, Ana P; Pais, Isabel P; Martins, Lima D; Silva, Maria J; Reboredo, Fernando H; Partelli, Fábio L; Campostrini, Eliemar; Tomaz, Marcelo A; Scotti-Campos, Paula; Ribeiro-Barros, Ana I; Lidon, Fernando J C; DaMatta, Fábio M; Ramalho, José C

    2016-01-01

    Modeling studies have predicted that coffee crop will be endangered by future global warming, but recent reports highlighted that high [CO2] can mitigate heat impacts on coffee. This work aimed at identifying heat protective mechanisms promoted by CO2 in Coffea arabica (cv. Icatu and IPR108) and Coffea canephora cv. Conilon CL153. Plants were grown at 25/20°C (day/night), under 380 or 700 μL CO2 L(-1), and then gradually submitted to 31/25, 37/30, and 42/34°C. Relevant heat tolerance up to 37/30°C for both [CO2] and all coffee genotypes was observed, likely supported by the maintenance or increase of the pools of several protective molecules (neoxanthin, lutein, carotenes, α-tocopherol, HSP70, raffinose), activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), and the upregulated expression of some genes (ELIP, Chaperonin 20). However, at 42/34°C a tolerance threshold was reached, mostly in the 380-plants and Icatu. Adjustments in raffinose, lutein, β-carotene, α-tocopherol and HSP70 pools, and the upregulated expression of genes related to protective (ELIPS, HSP70, Chape 20, and 60) and antioxidant (CAT, CuSOD2, APX Cyt, APX Chl) proteins were largely driven by temperature. However, enhanced [CO2] maintained higher activities of GR (Icatu) and CAT (Icatu and IPR108), kept (or even increased) the Cu,Zn-SOD, APX, and CAT activities, and promoted a greater upregulation of those enzyme genes, as well as those related to HSP70, ELIPs, Chaperonins in CL153, and Icatu. These changes likely favored the maintenance of reactive oxygen species (ROS) at controlled levels and contributed to mitigate of photosystem II photoinhibition at the highest temperature. Overall, our results highlighted the important role of enhanced [CO2] on the coffee crop acclimation and sustainability under predicted future global warming scenarios. PMID:27446174

  2. Drivers and barriers to heat stress resilience.

    PubMed

    Hatvani-Kovacs, Gertrud; Belusko, Martin; Skinner, Natalie; Pockett, John; Boland, John

    2016-11-15

    Heatwaves are the most dangerous natural hazard to health in Australia. The frequency and intensity of heatwaves will increase due to climate change and urban heat island effects in cities, aggravating the negative impacts of heatwaves. Two approaches exist to develop population heat stress resilience. Firstly, the most vulnerable social groups can be identified and public health services can prepare for the increased morbidity. Secondly, the population level of adaptation and the heat stress resistance of the built environment can be increased. The evaluation of these measures and their efficiencies has been fragmented across research disciplines. This study explored the relationships between the elements of heat stress resilience and their potential demographic and housing drivers and barriers. The responses of a representative online survey (N=393) about heat stress resilience at home and work from Adelaide, South Australia were analysed. The empirical findings demonstrate that heat stress resistant buildings increased adaptation capacity and decreased the number of health problems. Air-conditioning increased dependence upon it, limited passive adaptation and only people living in homes with whole-house air-conditioning had less health problems during heatwaves. Tenants and respondents with pre-existing health conditions were the most vulnerable, particularly as those with health conditions were not aware of their vulnerability. The introduction of an Energy Performance Certificate is proposed and discussed as an effective incentive to increase the heat stress resistance of and the general knowledge about the built environment. PMID:27432732

  3. Leaf proteome alterations in the context of physiological and morphological responses to drought and heat stress in barley (Hordeum vulgare L.).

    PubMed

    Rollins, J A; Habte, E; Templer, S E; Colby, T; Schmidt, J; von Korff, M

    2013-08-01

    The objective of this study was to identify barley leaf proteins differentially regulated in response to drought and heat and the combined stresses in context of the morphological and physiological changes that also occur. The Syrian landrace Arta and the Australian cultivar Keel were subjected to drought, high temperature, or a combination of both treatments starting at heading. Changes in the leaf proteome were identified using differential gel electrophoresis and mass spectrometry. The drought treatment caused strong reductions of biomass and yield, while photosynthetic performance and the proteome were not significantly changed. In contrast, the heat treatment and the combination of heat and drought reduced photosynthetic performance and caused changes of the leaf proteome. The proteomic analysis identified 99 protein spots differentially regulated in response to heat treatment, 14 of which were regulated in a genotype-specific manner. Differentially regulated proteins predominantly had functions in photosynthesis, but also in detoxification, energy metabolism, and protein biosynthesis. The analysis indicated that de novo protein biosynthesis, protein quality control mediated by chaperones and proteases, and the use of alternative energy resources, i.e. glycolysis, play important roles in adaptation to heat stress. In addition, genetic variation identified in the proteome, in plant growth and photosynthetic performance in response to drought and heat represent stress adaption mechanisms to be exploited in future crop breeding efforts. PMID:23918963

  4. Leaf proteome alterations in the context of physiological and morphological responses to drought and heat stress in barley (Hordeum vulgare L.)

    PubMed Central

    von Korff, M.

    2013-01-01

    The objective of this study was to identify barley leaf proteins differentially regulated in response to drought and heat and the combined stresses in context of the morphological and physiological changes that also occur. The Syrian landrace Arta and the Australian cultivar Keel were subjected to drought, high temperature, or a combination of both treatments starting at heading. Changes in the leaf proteome were identified using differential gel electrophoresis and mass spectrometry. The drought treatment caused strong reductions of biomass and yield, while photosynthetic performance and the proteome were not significantly changed. In contrast, the heat treatment and the combination of heat and drought reduced photosynthetic performance and caused changes of the leaf proteome. The proteomic analysis identified 99 protein spots differentially regulated in response to heat treatment, 14 of which were regulated in a genotype-specific manner. Differentially regulated proteins predominantly had functions in photosynthesis, but also in detoxification, energy metabolism, and protein biosynthesis. The analysis indicated that de novo protein biosynthesis, protein quality control mediated by chaperones and proteases, and the use of alternative energy resources, i.e. glycolysis, play important roles in adaptation to heat stress. In addition, genetic variation identified in the proteome, in plant growth and photosynthetic performance in response to drought and heat represent stress adaption mechanisms to be exploited in future crop breeding efforts. PMID:23918963

  5. A stress-responsive NAC transcription factor SNAC3 confers heat and drought tolerance through modulation of reactive oxygen species in rice

    PubMed Central

    Fang, Yujie; Liao, Kaifeng; Du, Hao; Xu, Yan; Song, Huazhi; Li, Xianghua; Xiong, Lizhong

    2015-01-01

    Adverse environmental conditions such as high temperature and drought stress greatly limit the growth and production of crops worldwide. Several NAC (NAM, ATAF1/2, and CUC2) proteins have been documented as important regulators in stress responses, but the molecular mechanisms are largely unknown. Here, a stress-responsive NAC gene, SNAC3 (ONAC003, LOC_Os01g09550), conferring drought and heat tolerance in rice is reported. SNAC3 was ubiquitously expressed and its transcript level was induced by drought, high temperature, salinity stress, and abscisic acid (ABA) treatment. Overexpression (OE) of SNAC3 in rice resulted in enhanced tolerance to high temperature, drought, and oxidative stress caused by methyl viologen (MV), whereas suppression of SNAC3 by RNAi resulted in increased sensitivity to these stresses. The SNAC3-OE transgenic plants exhibited significantly lower levels of H2O2, malondiadehyde (MDA), and relative electrolyte leakage than the wild-type control under heat stress conditions, implying that SNAC3 may confer stress tolerance by modulating reactive oxygen species (ROS) homeostasis. Quantitative PCR experiments showed that the expression of a large number of ROS-scavenging genes was dramatically increased in the SNAC3-OE plants, but significantly decreased in the SNAC3-RNAi transgenic plants. Five ROS-associated genes which were up-regulated in SNAC3-OE plants showed co-expression patterns with SNAC3, and three of the co-expressed ROS-associated enzyme genes were verified to be direct target genes of SNAC3. These results suggest that SNAC3 plays important roles in stress responses, and it is likely to be useful for engineering crops with improved tolerance to heat and drought stress. PMID:26261267

  6. Comparison of the heat stress induced variations in DNA methylation between heat-tolerant and heat-sensitive rapeseed seedlings

    PubMed Central

    Gao, Guizhen; Li, Jun; Li, Hao; Li, Feng; Xu, Kun; Yan, Guixin; Chen, Biyun; Qiao, Jiangwei; Wu, Xiaoming

    2014-01-01

    DNA methylation is responsive to various biotic and abiotic stresses. Heat stress is a serious threat to crop growth and development worldwide. Heat stress results in an array of morphological, physiological and biochemical changes in plants. The relationship between DNA methylation and heat stress in crops is relatively unknown. We investigated the differences in methylation levels and changes in the cytosine methylation patterns in seedlings of two rapeseed genotypes (heat-sensitive and heat-tolerant) under heat stress. Our results revealed that the methylation levels were different between a heat-tolerant genotype and a heat-sensitive one under control conditions. Under heat treatment, methylation increased more in the heat-sensitive genotype than in the heat-tolerant genotype. More DNA demethylation events occurred in the heat-tolerant genotype, while more DNA methylation occurred in the heat-sensitive genotype. A large and diverse set of genes were affected by heat stress via cytosine methylation changes, suggesting that these genes likely play important roles in the response and adaption to heat stress in Brassica napus L. This study indicated that the changes in DNA methylation differed between heat-tolerant and heat-sensitive genotypes of B. napus in response to heat stress, which further illuminates the molecular mechanisms of the adaption to heat stress in B. napus. PMID:24987298

  7. Gastric Fluid and Heat Stress Response of Listeria monocytogenes Inoculated on Frankfurters Formulated with 10%, 20%, and 30% Fat Content

    PubMed Central

    Kim, Hack-Youn; Kim, Cheon-Jei; Han, Sung Gu; Choi, Kyoung-Hee

    2014-01-01

    This study evaluated the effects of frankfurter fat content on Listeria monocytogenes resistance to heat stress and gastric fluid, and the Caco-2 cell invasion efficiency of the pathogen. A 10-strain mixture of L. monocytogenes was inoculated on frankfurters formulated with 10%, 20%, and 30% fat content (10%: F10, 20%: F20, 30%: F30) and stored at 10℃ for 30 d. The samples were analyzed for L. monocytogenes resistance to heat stress and a simulated gastric fluid challenge. The total bacteria and L. monocytogenes survival rates were measured on tryptic soy agar plus 0.6% yeast extract and Palcam agar, respectively. L. monocytogenes colonies inoculated on F10, F20, and F30 samples were used for a Caco-2 cell invasion assay. In general, no obvious differences were observed between the survival rates of total bacteria and L. monocytogenes grown on different fat contents under heat stress and gastric fluid challenge. However, L. monocytogenes obtained from the F30 samples had a significantly higher Caco-2 cell invasion efficiency than those in the F10 and F20 samples (p<0.05). These results indicate that although high fat content in food may not be related to L. monocytogenes resistance to heat stress and gastric fluid, it may increase the Caco-2 cell invasion efficiency of the pathogen. PMID:26760741

  8. The Quinone Methide Aurin Is a Heat Shock Response Inducer That Causes Proteotoxic Stress and Noxa-dependent Apoptosis in Malignant Melanoma Cells*

    PubMed Central

    Davis, Angela L.; Qiao, Shuxi; Lesson, Jessica L.; Rojo de la Vega, Montserrat; Park, Sophia L.; Seanez, Carol M.; Gokhale, Vijay; Cabello, Christopher M.; Wondrak, Georg T.

    2015-01-01

    Pharmacological induction of proteotoxic stress is rapidly emerging as a promising strategy for cancer cell-directed chemotherapeutic intervention. Here, we describe the identification of a novel drug-like heat shock response inducer for the therapeutic induction of proteotoxic stress targeting malignant human melanoma cells. Screening a focused library of compounds containing redox-directed electrophilic pharmacophores employing the Stress & Toxicity PathwayFinderTM PCR Array technology as a discovery tool, a drug-like triphenylmethane-derivative (aurin; 4-[bis(p-hydroxyphenyl)methylene]-2,5-cyclohexadien-1-one) was identified as an experimental cell stress modulator that causes (i) heat shock factor transcriptional activation, (ii) up-regulation of heat shock response gene expression (HSPA6, HSPA1A, DNAJB4, HMOX1), (iii) early unfolded protein response signaling (phospho-PERK, phospho-eIF2α, CHOP (CCAAT/enhancer-binding protein homologous protein)), (iv) proteasome impairment with increased protein-ubiquitination, and (v) oxidative stress with glutathione depletion. Fluorescence polarization-based experiments revealed that aurin displays activity as a geldanamycin-competitive Hsp90α-antagonist, a finding further substantiated by molecular docking and ATPase inhibition analysis. Aurin exposure caused caspase-dependent cell death in a panel of human malignant melanoma cells (A375, G361, LOX-IMVI) but not in non-malignant human skin cells (Hs27 fibroblasts, HaCaT keratinocytes, primary melanocytes) undergoing the aurin-induced heat shock response without impairment of viability. Aurin-induced melanoma cell apoptosis depends on Noxa up-regulation as confirmed by siRNA rescue experiments demonstrating that siPMAIP1-based target down-regulation suppresses aurin-induced cell death. Taken together, our data suggest feasibility of apoptotic elimination of malignant melanoma cells using the quinone methide-derived heat shock response inducer aurin. PMID:25477506

  9. Effects of obesity and mild hypohydration on local sweating and cutaneous vascular responses during passive heat stress in females.

    PubMed

    Moyen, Nicole E; Burchfield, Jenna M; Butts, Cory L; Glenn, Jordan M; Tucker, Matthew A; Treece, Keeley; Smith, Amber J; McDermott, Brendon P; Ganio, Matthew S

    2016-08-01

    The purpose of this study was to evaluate the effect of obesity and mild hypohydration on local sweating (LSR) and cutaneous vascular conductance (CVC) responses during passive heat stress in females. Thirteen obese (age, 24 ± 4 years; 45.4% ± 5.2% body fat) and 12 nonobese (age, 22 ± 2 years; 25.1% ± 3.9% body fat) females were passively heated (1.0 °C rectal temperature increase) while either euhydrated (EUHY) or mildly hypohydrated (HYPO; via fluid restriction). Chest and forearm LSR (ventilated capsule) and CVC (Laser Doppler flowmetry) onset, sensitivity, and plateau/steady state were recorded as mean body temperature increased (ΔTb). Participants began trials EUHY (urine specific gravity, Usg = 1.009 ± 0.006) or HYPO (Usg = 1.025 ± 0.004; p < 0.05), and remained EUHY or HYPO. Independent of obesity, HYPO decreased sweat sensitivity at the chest (HYPO = 0.79 ± 0.35, EUHY = 0.95 ± 0.39 Δmg·min(-1)·cm(-2)/°C ΔTb) and forearm (HYPO = 0.82 ± 0.39, EUHY = 1.06 ± 0.34 Δmg·min(-1)·cm(-2)/°C ΔTb); forearm LSR plateau was also decreased (HYPO = 0.66 ± 0.19, EUHY = 0.78 ± 0.23 mg·min(-1)·cm(-2); all p < 0.05). Overall, obese females had lower chest-sweat sensitivity (0.72 ± 0.35 vs. 1.01 ± 0.33 Δmg·min(-1)·cm(-2)/°C ΔTb) and plateau (0.55 ± 0.27 vs. 0.80 ± 0.25 mg·min(-1)·cm(-2); p < 0.05). While hypohydrated, obese females had a lower chest LSR (p < 0.05) versus nonobese females midway (0.45 ± 0.26 vs. 0.73 ± 0.23 mg·min(-1)·cm(-2)) and at the end (0.53 ± 0.27 vs. 0.81 ± 0.24 mg·min(-1)·cm(-2)) of heating. Furthermore, HYPO (relative to the EUHY trials) led to a greater decrease in CVC sensitivity in obese (-28 ± 27 Δ% maximal CVC/°C ΔTb) versus nonobese females (+9.2 ± 33 Δ% maximal CVC/°C ΔTb; p < 0.05). In conclusion, mild hypohydration impairs females' sweating responses during passive heat stress, and this effect is exacerbated when obese. PMID:27455036

  10. Ambiguous response of lung lamellar bodies to sauna-like heat stress in two age groups of adult male rats.

    PubMed

    Heino, M E

    1980-06-01

    Two groups of adult male rats, aged 2.5 and 5 months, were exposed daily for 12 min to 65 degrees C for five successive periods a week for 6 weeks. Both age groups, and in particular the young one, repeatedly suffered from exhausting heat stress. Lung specimens from cardiac lobes were prepared for light- and electron-microscopy. A significnat increase was noted in the lung lamellar body number in the old test rats, on comparison with old ones employed as controls (p < 0.05). The young group was unresponsive. Consequently, stress induced by increased sympathetic activity is not always a direct stimulus, as had been thought earlier. It seems, at least where heat stress is concerned, that it is the age, weight, and systemic reactions which exercise a great influence upon lamellar body production, and may even overrule the role of sympathetic activity. PMID:7417113

  11. Plastid casein kinase 2 knockout reduces abscisic acid (ABA) sensitivity, thermotolerance, and expression of ABA- and heat-stress-responsive nuclear genes.

    PubMed

    Wang, Yu; Chang, Hongping; Hu, Shuai; Lu, Xiutao; Yuan, Congying; Zhang, Chen; Wang, Ping; Xiao, Wenjun; Xiao, Langtao; Xue, Gang-Ping; Guo, Xinhong

    2014-08-01

    Plastid casein kinase 2 (CK2) is a major Ser/Thr-specific enzyme for protein phosphorylation in the chloroplast stroma and its kinase activity is regulated by redox signals. To understand the role of CK2 phosphorylation of chloroplast proteins in abiotic stress signalling, an Arabidopsis plastid CK2 (CKA4) knockout mutant was investigated in terms of the plant response to abscisic acid (ABA) and heat stress. CKA4 expression was upregulated by ABA and heat treatment. The cka4 mutant showed reduced sensitivity to ABA during seed germination and seedling growth, and increased stomatal aperture and leaf water loss with a slightly reduced leaf ABA level. The cka4 mutant was more sensitive to heat stress than the wild-type Columbia-0. The expression levels of a number of genes in the ABA regulatory network were reduced in the cka4 mutant. Many heat-upregulated genes (heat-shock factors and heat-shock proteins) were also reduced in the cka4 mutant. The cka4 mutant showed reduced expression levels of plastid-encoded RNA polymerase target genes (atpB and psbA). CKA4 knockout mutation also resulted in a reduction in expression of some critical genes (PTM, ABI4, and PRS1) involved in retrograde signalling from the chloroplast to the nucleus. Similar results were observed in mutant plants with the knockout mutation in both CKA4 and CKA3, which encodes a nuclear CK2 α3 subunit. CKA3 expression was not responsive to ABA and heat stress. These results suggest that CKA4 is an enhancing factor in abiotic stress signalling through modulating the expression of some molecular players in retrograde signalling. PMID:24803505

  12. Plastid casein kinase 2 knockout reduces abscisic acid (ABA) sensitivity, thermotolerance, and expression of ABA- and heat-stress-responsive nuclear genes

    PubMed Central

    Wang, Yu; Chang, Hongping; Hu, Shuai; Lu, Xiutao; Yuan, Congying; Zhang, Chen; Wang, Ping; Xiao, Wenjun; Xiao, Langtao; Xue, Gang-Ping; Guo, Xinhong

    2014-01-01

    Plastid casein kinase 2 (CK2) is a major Ser/Thr-specific enzyme for protein phosphorylation in the chloroplast stroma and its kinase activity is regulated by redox signals. To understand the role of CK2 phosphorylation of chloroplast proteins in abiotic stress signalling, an Arabidopsis plastid CK2 (CKA4) knockout mutant was investigated in terms of the plant response to abscisic acid (ABA) and heat stress. CKA4 expression was upregulated by ABA and heat treatment. The cka4 mutant showed reduced sensitivity to ABA during seed germination and seedling growth, and increased stomatal aperture and leaf water loss with a slightly reduced leaf ABA level. The cka4 mutant was more sensitive to heat stress than the wild-type Columbia-0. The expression levels of a number of genes in the ABA regulatory network were reduced in the cka4 mutant. Many heat-upregulated genes (heat-shock factors and heat-shock proteins) were also reduced in the cka4 mutant. The cka4 mutant showed reduced expression levels of plastid-encoded RNA polymerase target genes (atpB and psbA). CKA4 knockout mutation also resulted in a reduction in expression of some critical genes (PTM, ABI4, and PRS1) involved in retrograde signalling from the chloroplast to the nucleus. Similar results were observed in mutant plants with the knockout mutation in both CKA4 and CKA3, which encodes a nuclear CK2 α3 subunit. CKA3 expression was not responsive to ABA and heat stress. These results suggest that CKA4 is an enhancing factor in abiotic stress signalling through modulating the expression of some molecular players in retrograde signalling. PMID:24803505

  13. Improved Heat-Stress Algorithm

    NASA Technical Reports Server (NTRS)

    Teets, Edward H., Jr.; Fehn, Steven

    2007-01-01

    NASA Dryden presents an improved and automated site-specific algorithm for heat-stress approximation using standard atmospheric measurements routinely obtained from the Edwards Air Force Base weather detachment. Heat stress, which is the net heat load a worker may be exposed to, is officially measured using a thermal-environment monitoring system to calculate the wet-bulb globe temperature (WBGT). This instrument uses three independent thermometers to measure wet-bulb, dry-bulb, and the black-globe temperatures. By using these improvements, a more realistic WBGT estimation value can now be produced. This is extremely useful for researchers and other employees who are working on outdoor projects that are distant from the areas that the Web system monitors. Most importantly, the improved WBGT estimations will make outdoor work sites safer by reducing the likelihood of heat stress.

  14. Annotation of Differential Gene Expression in Small Yellow Follicles of a Broiler-Type Strain of Taiwan Country Chickens in Response to Acute Heat Stress

    PubMed Central

    Wang, Shih-Han; Tang, Pin-Chi; Chen, Chih-Feng; Chen, Hsin-Hsin; Lee, Yen-Pai; Chen, Shuen-Ei; Huang, San-Yuan

    2015-01-01

    This study investigated global gene expression in the small yellow follicles (6–8 mm diameter) of broiler-type B strain Taiwan country chickens (TCCs) in response to acute heat stress. Twelve 30-wk-old TCC hens were divided into four groups: control hens maintained at 25°C and hens subjected to 38°C acute heat stress for 2 h without recovery (H2R0), with 2-h recovery (H2R2), and with 6-h recovery (H2R6). Small yellow follicles were collected for RNA isolation and microarray analysis at the end of each time point. Results showed that 69, 51, and 76 genes were upregulated and 58, 15, 56 genes were downregulated after heat treatment of H2R0, H2R2, and H2R6, respectively, using a cutoff value of two-fold or higher. Gene ontology analysis revealed that these differentially expressed genes are associated with the biological processes of cell communication, developmental process, protein metabolic process, immune system process, and response to stimuli. Upregulation of heat shock protein 25, interleukin 6, metallopeptidase 1, and metalloproteinase 13, and downregulation of type II alpha 1 collagen, discoidin domain receptor tyrosine kinase 2, and Kruppel-like factor 2 suggested that acute heat stress induces proteolytic disintegration of the structural matrix and inflamed damage and adaptive responses of gene expression in the follicle cells. These suggestions were validated through gene expression, using quantitative real-time polymerase chain reaction. Functional annotation clarified that interleukin 6-related pathways play a critical role in regulating acute heat stress responses in the small yellow follicles of TCC hens. PMID:26587838

  15. Annotation of Differential Gene Expression in Small Yellow Follicles of a Broiler-Type Strain of Taiwan Country Chickens in Response to Acute Heat Stress.

    PubMed

    Cheng, Chuen-Yu; Tu, Wei-Lin; Wang, Shih-Han; Tang, Pin-Chi; Chen, Chih-Feng; Chen, Hsin-Hsin; Lee, Yen-Pai; Chen, Shuen-Ei; Huang, San-Yuan

    2015-01-01

    This study investigated global gene expression in the small yellow follicles (6-8 mm diameter) of broiler-type B strain Taiwan country chickens (TCCs) in response to acute heat stress. Twelve 30-wk-old TCC hens were divided into four groups: control hens maintained at 25°C and hens subjected to 38°C acute heat stress for 2 h without recovery (H2R0), with 2-h recovery (H2R2), and with 6-h recovery (H2R6). Small yellow follicles were collected for RNA isolation and microarray analysis at the end of each time point. Results showed that 69, 51, and 76 genes were upregulated and 58, 15, 56 genes were downregulated after heat treatment of H2R0, H2R2, and H2R6, respectively, using a cutoff value of two-fold or higher. Gene ontology analysis revealed that these differentially expressed genes are associated with the biological processes of cell communication, developmental process, protein metabolic process, immune system process, and response to stimuli. Upregulation of heat shock protein 25, interleukin 6, metallopeptidase 1, and metalloproteinase 13, and downregulation of type II alpha 1 collagen, discoidin domain receptor tyrosine kinase 2, and Kruppel-like factor 2 suggested that acute heat stress induces proteolytic disintegration of the structural matrix and inflamed damage and adaptive responses of gene expression in the follicle cells. These suggestions were validated through gene expression, using quantitative real-time polymerase chain reaction. Functional annotation clarified that interleukin 6-related pathways play a critical role in regulating acute heat stress responses in the small yellow follicles of TCC hens. PMID:26587838

  16. Gene Expression Profiles of Heat Shock Proteins 70 and 90 From Empoasca onukii (Hemiptera: Cicadellidae) in Response to Temperature Stress

    PubMed Central

    Qiao, Li; Wu, Jun X.; Qin, Dao Z.; Liu, Xiang C.; Lu, Zhao C.; Lv, Li Z.; Pan, Zi L.; Chen, Hao; Li, Guang W.

    2015-01-01

    Empoasca onukii Matsuda is a worldwide pest that causes great economic loss in tea growing areas and is significantly affected by temperatures. Heat shock protein (Hsp) genes are important in insects’ response to temperature stress. In this study, two full-length Hsp genes, Eohsp90 and Eohsp70, were cloned from E. onukii using rapid amplification of complementary DNA ends. The open reading frames of Eohsp90 and Eohsp70 were 2,172 bp and 2,016 bp in length, respectively. Their deduced amino acid sequences of Eohsp90 and Eohsp70 showed high homology with other species. Subsequently, the transcriptional expression of Eohsp90 and Eohsp70 in E. onukii adults exposed to various temperatures (−5, 0, 10, 15, 20, 25, 30, 35, 38, 41 and 44°C) for 1 h, and at extreme temperatures (0°C and 41°C) for various time duration (0, 20, 40, 60, 80, 100, and 120 min) were investigated via real-time quantitative polymerase chain reaction. The relative expression levels of both Eohsp90 and Eohsp70 in E. onukii adults were upregulated as the temperature rises or falls over time, except in the −5°C or 44°C temperature groups. Moreover, the expression level in the temperature elevated groups was higher than that of the lower temperature groups. In addition, the Eohsp70 generally demonstrated a higher transcriptional level than Eohsp90, and both genes had a higher expression profile in female adults compared with the males. The expression profiles indicated that Eohsp90 and Eohsp70 may play important roles in E. onukii adult responses to ecologically relevant environmental temperature threat. PMID:25888707

  17. Response of Urban Systems to Climate Change in Europe: Heat Stress Exposure and the Effect on Human Health

    NASA Astrophysics Data System (ADS)

    Stevens, Catherine; Thomas, Bart; Grommen, Mart

    2015-04-01

    Climate change is driven by global processes such as the global ocean circulation and its variability over time leading to changing weather patterns on regional scales as well as changes in the severity and occurrence of extreme events such as heavy rain- and windstorms, floods, drought, heat waves, etc. The summer 2003 European heat wave was the hottest summer on record in Europe over the past centuries leading to health crises in several countries like France and caused up to 70.000 excess deaths over four months in Central and Western Europe. The main risks induced by global climate change in urbanised areas are considered to be overheating and resulting health effects, increased exposure to flood events, increased damage losses from extreme weather conditions but also shortages in the provision of life-sustaining services. Moreover, the cities themselves create specific or inherent risks and urban adaptation is often very demanding. As most of Europe's inhabitants live in cities, it is of particular relevance to examine the impact of climate variability on urban areas and their populations. The present study focusses on the identification of heat stress variables related to human health and the extraction of this information by processing daily temperature statistics of local urban climate simulations over multiple timeframes of 20 years and three different European cities based on recent, near future and far future global climate predictions. The analyses have been conducted in the framework of the NACLIM FP7 project funded by the European Commission involving local stakeholders such as the cities of Antwerp (Belgium), Berlin (Germany) and Almada (Portugal) represented by different climate and urban characteristics. Apart from the urban-rural temperature increment (urban heat island effect), additional heat stress parameters such as the average number of heat wave days together with their duration and intensities have been covered during this research. In a

  18. Changes in polyphenol and sugar concentrations in wild type and genetically modified Nicotiana langsdorffii Weinmann in response to water and heat stress.

    PubMed

    Ancillotti, Claudia; Bogani, Patrizia; Biricolti, Stefano; Calistri, Elisa; Checchini, Leonardo; Ciofi, Lorenzo; Gonnelli, Cristina; Del Bubba, Massimo

    2015-12-01

    In this study wild type Nicotiana langsdorffii plants were genetically transformed by the insertion of the rat gene (gr) encoding the glucocorticoid receptor or the rolC gene and exposed to water and heat stress. Water stress was induced for 15 days by adding 20% PEG 6000 in the growth medium, whereas the heat treatment was performed at 50 °C for 2 h, after that a re-growing capability study was carried out. The plant response to stress was investigated by determining electrolyte leakage, dry weight biomass production and water content. These data were evaluated in relation to antiradical activity and concentrations of total polyphenols, selected phenolic compounds and some soluble sugars, as biochemical indicators of metabolic changes due to gene insertion and/or stress treatments. As regards the water stress, the measured physiological parameters evidenced an increasing stress level in the order rolC < gr < WT plants (e.g. about 100% and 50% electrolyte leakage increase in WT and gr samples, respectively) and complied with the biochemical pattern, which consisted in a general decrease of antiradical activity and phenolics, together with an increase in sugars. As regard heat stress, electrolyte leakage data were only in partial agreement with the re-growing capability study. In fact, according to this latter evaluation, gr was the genotype less affected by the heat shock. In this regard, sugars and especially phenolic compounds are informative of the long-term effects due to heat shock treatment. PMID:26410575

  19. Heat shock protein 47 stress responses in Chinese hamster ovary cells exposed to raw and reclaimed wastewater.

    PubMed

    Guizani, Mokhtar; Nogoshi, Yosuke; Ben Fredj, Fahmi; Han, Junkyu; Isoda, Hiroko; Funamizu, Naoyuki

    2012-02-01

    As wastewater reclamation and reuse becomes more widespread, risks of exposure to treated wastewater increase. Moreover, an unlimited number of pollutants can be identified in wastewater. Therefore, comprehensive toxicity assessment of treated wastewater is imperative. The objective of this study was to perform a comprehensive toxicity assessment of wastewater treatment systems using stress response bioassays. This powerful tool can comprehensively assess the toxicity of contaminants. In this study, samples from conventional activated sludge treatment, membrane bioreactors (MBRs) with different pore sizes and sludge retention times (SRTs), rapid sand filtration, coagulation, nano-filtration (NF) and reverse osmosis (RO) were investigated. The results of stress response bioassays confirmed that the secondary effluent showed higher stress response than influent indicating that biological treatment generates toxic compounds. The results obtained from molecular weight fractionation of water samples demonstrated that organic matter with a higher molecular weight fraction (>0.1 μm) causes toxicity in secondary effluent. Furthermore, supernatant from MBR reactors showed toxicity regardless of SRT. On the other hand, stress response was not detected in MBR permeates except for an MBR equipped with a larger pore size membrane (0.4 μm) and with a short SRT (12 days). While rapid sand filtration could not remove the toxic compounds found in secondary effluent, coagulation tests, operated at an appropriate pH, were effective for reducing stress response in the secondary effluent. Experimental findings also showed that stress response was not detected in cases of NF and RO permeate subsequent to MBR treatment. PMID:22159031

  20. Effects of heat stress on baroreflex function in humans

    NASA Technical Reports Server (NTRS)

    Crandall, Craig G.; Cui, Jian; Wilson, Thad E.

    2003-01-01

    INTRODUCTION: Heat stress significantly reduces orthostatic tolerance in humans. The mechanism(s) causing this response remain unknown. The purpose of this review article is to present data pertaining to the hypothesis that reduced orthostatic tolerance in heat stressed individuals is a result of heat stress induced alterations in baroflex function. METHODS: In both normothermic and heat stressed conditions baroreflex responsiveness was assessed via pharmacological and non-pharmacological methods. In addition, the effects of heat stress on post-synaptic vasoconstrictor responsiveness were assessed. RESULTS: Generally, whole body heating did not alter baroreflex sensitivity defined as the gain of the linear portion of the baroreflex curve around the operating point. However, whole body heating shifted the baroreflex curve to the prevailing (i.e. elevated) heart rate and muscle sympathetic nerve activity. Finally, the heat stress impaired vasoconstrictor responses to exogenous administration of adrenergic agonists. CONCLUSION: Current data do not support the hypothesis that reduced orthostatic tolerance associated with heat stress in humans is due to impaired baroreflex responsiveness. This phenomenon may be partially due to the effects of heat stress on reducing vasoconstrictor responsiveness.

  1. Heat and Osmotic Stress Responses of Probiotic Lactobacillus rhamnosus HN001 (DR20) in Relation to Viability after Drying

    PubMed Central

    Prasad, Jaya; McJarrow, Paul; Gopal, Pramod

    2003-01-01

    The viability of lactic acid bacteria in frozen, freeze-dried, and air-dried forms is of significant commercial interest to both the dairy and food industries. In this study we observed that when prestressed with either heat (50°C) or salt (0.6 M NaCl), Lactobacillus rhamnosus HN001 (also known as DR20) showed significant (P < 0.05) improvement in viability compared with the nonstressed control culture after storage at 30°C in the dried form. To investigate the mechanisms underlying this stress-related viability improvement in L. rhamnosus HN001, we analyzed protein synthesis in cultures subjected to different growth stages and stress conditions, using two-dimensional gel electrophoresis and N-terminal sequencing. Several proteins were up- or down-regulated after either heat or osmotic shock treatments. Eleven proteins were positively identified, including the classical heat shock proteins GroEL and DnaK and the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, enolase, phosphoglycerate kinase, and triose phosphate isomerase, as well as tagatose 1,6-diphosphate aldolase of the tagatose pathway. The phosphocarrier protein HPr (histidine-containing proteins) was up-regulated in cultures after the log phase irrespective of the stress treatments used. The relative synthesis of an ABC transport-related protein was also up-regulated after shock treatments. Carbohydrate analysis of cytoplasmic contents showed higher levels (20 ± 3 μg/mg of protein) in cell extracts (CFEs) derived from osmotically stressed cells than in the unstressed control (15 ± 3 μg/mg of protein). Liquid chromatography of these crude carbohydrate extracts showed significantly different profiles. Electrospray mass spectrometry analysis of CFEs revealed, in addition to normal mono-, di-, tri-, and tetrasaccharides, the presence of saccharides modified with glycerol. PMID:12571012

  2. Oxidative stress is involved in the heat stress-induced downregulation of TCR zeta chain expression and TCR/CD3-mediated [Ca(2+)](i) response in human T-lymphocytes.

    PubMed

    Nambiar, Madhusoodana P; Fisher, Carolyn U; Enyedy, Edith J; Warke, Vishal G; Kumar, Anil; Tsokos, George C

    2002-02-01

    Exposure of human T-lymphocytes to heat downregulates TCR zeta chain expression and inhibits (TCR)/CD3-mediated production of inositol triphosphate and [Ca(2+)](i) signaling. Here we investigated whether oxidative stress is involved in the heat-induced downregulation of TCR/CD3-mediated signaling. To this end, we have studied the effect of a thiol antioxidant, N-acetyl-L-cysteine (NAC), and a non-thiol antioxidant, allopurinol, on heat-induced downregulation of TCR/CD3-mediated signaling. We found that preincubation of cells with 10mM NAC significantly reversed the downregulation of TCR/CD3-mediated [Ca(2+)](i) response and restored the suppression of TCR zeta chain protein expression as well as prevented its increased membrane distribution in heat-treated cells. NAC also reversed the downregulation of TCR zeta chain mRNA expression and the active 94kDa TCR zeta chain transcription factor, Elf-1, in heat-treated cells. Consistent with the increase in the TCR zeta chain, preincubation with NAC increased the levels of antigen receptor-induced tyrosine phosphorylation of several cytosolic proteins. Finally, treatment with NAC was able to reverse the suppression of IL-2 production in heat-treated cells. Inactive analog, N-acetylserine, failed to reverse the heat-induced downregulation of TCR/CD3-mediated signaling. Allopurinol, another potent non-thiol antioxidant, also restored the TCR/CD3-mediated [Ca(2+)](i) response in heat-treated cells. These results demonstrate that antioxidants restore the expression of TCR zeta chain and reverse the TCR/CD3-mediated signaling abnormalities associated with heat stress and suggest that heat shock-induced oxidative stress is a mediator of the heat-induced biochemical damage that leads to downregulation of signaling in human T-lymphocytes. PMID:12202152

  3. Genome-Wide Transcriptome Analysis During Anthesis Reveals New Insights into the Molecular Basis of Heat Stress Responses in Tolerant and Sensitive Rice Varieties.

    PubMed

    González-Schain, Nahuel; Dreni, Ludovico; Lawas, Lovely M F; Galbiati, Massimo; Colombo, Lucia; Heuer, Sigrid; Jagadish, Krishna S V; Kater, Martin M

    2016-01-01

    Rice is one of the main food crops in the world. In the near future, yield is expected to be under pressure due to unfavorable climatic conditions, such as increasing temperatures. Therefore, improving rice germplasm in order to guarantee rice production under harsh environmental conditions is of top priority. Although many physiological studies have contributed to understanding heat responses during anthesis, the most heat-sensitive stage, molecular data are still largely lacking. In this study, an RNA-sequencing approach of heat- and control-treated reproductive tissues during anthesis was carried out using N22, one of the most heat-tolerant rice cultivars known to date. This analysis revealed that expression of genes encoding a number of transcription factor families, together with signal transduction and metabolic pathway genes, is repressed. On the other hand, expression of genes encoding heat shock factors and heat shock proteins was highly activated. Many of these genes are predominantly expressed at late stages of anther development. Further physiological experiments using heat-tolerant N22 and two sensitive cultivars suggest that reduced yield in heat-sensitive plants may be associated with poor pollen development or production in anthers prior to anthesis. In parallel, induction levels of a set of heat-responsive genes in these tissues correlated well with heat tolerance. Altogether, these findings suggest that proper expression of protective chaperones in anthers is needed before anthesis to overcome stress damage and to ensure fertilization. Genes putatively controlling this process were identified and are valuable candidates to consider for molecular breeding of highly productive heat-tolerant cultivars. PMID:26561535

  4. Performance traits and immune response of broiler chicks treated with zinc and ascorbic acid supplementation during cyclic heat stress

    NASA Astrophysics Data System (ADS)

    Chand, Naila; Naz, Shabana; Khan, Ajab; Khan, Sarzamin; Khan, Rifat Ullah

    2014-12-01

    This research was conducted to investigate the effect of supplementation of zinc (Zn) and ascorbic acid (AA) in heat-stressed broilers. A total of 160-day-old broiler chicks of approximately the same weight and appearance were divided into four treatment groups (control, T1, T2, and T3). Control group was fed a standard diet without any supplementation. T1 was supplemented with Zn at the rate of 60 mg/kg of feed, T2 was supplemented with 300 mg/kg of feed AA, and T3 was supplemented with combination of Zn and AA. From week 3 to 5, heat stress environment was provided at the rate of 12 h at 25 °C, 3 h at 25 to 34 °C, 6 h at 34 °C, and 3 h at 34 to 25 °C daily. The results revealed that feed intake, body weight and feed conversion ratio (FCR), and weight of thymus, spleen, and bursa of Fabricius improved significantly ( P < 0.05) in T3 compared to the other treatments. Antibody titer against Newcastle disease (ND), infectious bursal disease (IBD), and infectious bronchitis (IB) increased significantly ( P < 0.05) in T2 and T3 groups. However, total leucocytes count, lymphocytes, and monocytes increased ( P < 0.05) in all treated groups compared to control. The results indicated that the supplementation of Zn or AA alone or in combination improved the performance and immune status of broilers reared under heat stress.

  5. Effect of "heat shock" treatments on QPX disease and stress response in the hard clam, Mercenaria mercenaria.

    PubMed

    Wang, Kailai; Pales Espinosa, Emmanuelle; Allam, Bassem

    2016-07-01

    The hard clam, Mercenaria mercenaria, is one of the most valuable commercial mollusk species along the eastern coast of the United States. Throughout the past 2 decades, the hard clam industry in the Northeast was significantly impacted by disease outbreaks caused by a lethal protistan parasite known as Quahog Parasite Unknown (QPX). QPX is an opportunistic pathogen and the infection has been shown to be a cold water disease, where warmer conditions (above 21°C) lead to disease reduction and clam healing. In vitro studies also showed a sharp reduction in parasite growth and survivorship at temperatures exceeding 27°C. In this study, we evaluated the effect of short-term exposures to high temperatures on QPX disease dynamic and clam recovery. Infected clams were collected from an enzootic site and subsequently submitted to one of ten "heat shock" treatments involving a gradient of temperatures and exposure times. QPX prevalence was compared before and 10weeks after heat shock to assess the effect of each treatment on disease progress. Expression of several stress-related genes was measured 1 and 7days after heat shock using qPCR to evaluate the effect of each treatment on clam physiology. Anti-QPX activity in clam plasma was also measured in an attempt to link changes in defense factors to thermal stress and disease progress. Our results suggest that brief exposures to moderate high temperatures promote the greatest remission while imposing the mildest stress to clams. These results are discussed with the aim of providing the industry with possible strategies to mitigate QPX disease. PMID:27269885

  6. De novo assembly and characterization of Muscovy duck liver transcriptome and analysis of differentially regulated genes in response to heat stress.

    PubMed

    Zeng, Tao; Zhang, Liping; Li, Jinjun; Wang, Deqian; Tian, Yong; Lu, Lizhi

    2015-05-01

    High temperature is a major abiotic stress limiting animal growth and productivity worldwide. The Muscovy duck (Cairina moschata), sometimes called the Barbary drake, is a type of duck with a fairly unusual domestication history. In Southeast Asia, duck meat is one of the top meats consumed, and as such, the production of the meat is an important topic of research. The transcriptomic and genomic data presently available are insufficient to understanding the molecular mechanism underlying the heat tolerance of Muscovy ducks. Thus, transcriptome and expression profiling data for this species are required as important resource for identifying genes and developing molecular marker. In this study, de novo transcriptome assembly and gene expression analysis using Illumina sequencing technology were performed. More than 225 million clean reads were generated and assembled into 36,903 unique transcripts with an average length of 1,135 bp. A total of 21,221 (57.50 %) unigenes were annotated. Gene Ontology (GO) analysis of the annotated unigenes revealed that the majority of sequenced genes were associated with transcription, signal transduction, and apoptosis. We also performed gene expression profiling analysis upon heat treatment in Muscovy ducks and identified 470 heat-response unique transcripts. GO term enrichment showed that protein folding and chaperone binding were significant enrichment, whereas KEGG pathway analyses showed that Ras and MAPKs were activated after heat stress in Muscovy ducks. Our research enriched sequences information of Muscovy duck, provided novel insights into responses to heat stress in these ducks, and serve as candidate genes or markers that can be used to guide future efforts to breed heat-tolerant duck strains. PMID:25663538

  7. Glutathionylation of the Bacterial Hsp70 Chaperone DnaK Provides a Link between Oxidative Stress and the Heat Shock Response.

    PubMed

    Zhang, Hong; Yang, Jie; Wu, Si; Gong, Weibin; Chen, Chang; Perrett, Sarah

    2016-03-25

    DnaK is the major bacterial Hsp70, participating in DNA replication, protein folding, and the stress response. DnaK cooperates with the Hsp40 co-chaperone DnaJ and the nucleotide exchange factor GrpE. Under non-stress conditions, DnaK binds to the heat shock transcription factor σ(32)and facilitates its degradation. Oxidative stress results in temporary inactivation of DnaK due to depletion of cellular ATP and thiol modifications such as glutathionylation until normal cellular ATP levels and a reducing environment are restored. However, the biological significance of DnaK glutathionylation remains unknown, and the mechanisms by which glutathionylation may regulate the activity of DnaK are also unclear. We investigated the conditions under which Escherichia coli DnaK undergoesS-glutathionylation. We observed glutathionylation of DnaK in lysates of E. coli cells that had been subjected to oxidative stress. We also obtained homogeneously glutathionylated DnaK using purified DnaK in the apo state. We found that glutathionylation of DnaK reversibly changes the secondary structure and tertiary conformation, leading to reduced nucleotide and peptide binding ability. The chaperone activity of DnaK was reversibly down-regulated by glutathionylation, accompanying the structural changes. We found that interaction of DnaK with DnaJ, GrpE, or σ(32)becomes weaker when DnaK is glutathionylated, and the interaction is restored upon deglutathionylation. This study confirms that glutathionylation down-regulates the functions of DnaK under oxidizing conditions, and this down-regulation may facilitate release of σ(32)from its interaction with DnaK, thus triggering the heat shock response. Such a mechanism provides a link between oxidative stress and the heat shock response in bacteria. PMID:26823468

  8. Glutathionylation of the Bacterial Hsp70 Chaperone DnaK Provides a Link between Oxidative Stress and the Heat Shock Response*

    PubMed Central

    Zhang, Hong; Yang, Jie; Wu, Si; Gong, Weibin; Chen, Chang; Perrett, Sarah

    2016-01-01

    DnaK is the major bacterial Hsp70, participating in DNA replication, protein folding, and the stress response. DnaK cooperates with the Hsp40 co-chaperone DnaJ and the nucleotide exchange factor GrpE. Under non-stress conditions, DnaK binds to the heat shock transcription factor σ32 and facilitates its degradation. Oxidative stress results in temporary inactivation of DnaK due to depletion of cellular ATP and thiol modifications such as glutathionylation until normal cellular ATP levels and a reducing environment are restored. However, the biological significance of DnaK glutathionylation remains unknown, and the mechanisms by which glutathionylation may regulate the activity of DnaK are also unclear. We investigated the conditions under which Escherichia coli DnaK undergoes S-glutathionylation. We observed glutathionylation of DnaK in lysates of E. coli cells that had been subjected to oxidative stress. We also obtained homogeneously glutathionylated DnaK using purified DnaK in the apo state. We found that glutathionylation of DnaK reversibly changes the secondary structure and tertiary conformation, leading to reduced nucleotide and peptide binding ability. The chaperone activity of DnaK was reversibly down-regulated by glutathionylation, accompanying the structural changes. We found that interaction of DnaK with DnaJ, GrpE, or σ32 becomes weaker when DnaK is glutathionylated, and the interaction is restored upon deglutathionylation. This study confirms that glutathionylation down-regulates the functions of DnaK under oxidizing conditions, and this down-regulation may facilitate release of σ32 from its interaction with DnaK, thus triggering the heat shock response. Such a mechanism provides a link between oxidative stress and the heat shock response in bacteria. PMID:26823468

  9. Species–specific interactions between algal endosymbionts and coral hosts define their bleaching response to heat and light stress

    PubMed Central

    Abrego, David; Ulstrup, Karin E; Willis, Bette L; van Oppen, Madeleine J.H

    2008-01-01

    The impacts of warming seas on the frequency and severity of bleaching events are well documented, but the potential for different Symbiodinium types to enhance the physiological tolerance of reef corals is not well understood. Here we compare the functionality and physiological properties of juvenile corals when experimentally infected with one of two homologous Symbiodinium types and exposed to combined heat and light stress. A suite of physiological indicators including chlorophyll a fluorescence, oxygen production and respiration, as well as pigment concentration consistently demonstrated lower metabolic costs and enhanced physiological tolerance of Acropora tenuis juveniles when hosting Symbiodinium type C1 compared with type D. In other studies, the same D-type has been shown to confer higher thermal tolerance than both C2 in adults and C1 in juveniles of the closely related species Acropora millepora. Our results challenge speculations that associations with type D are universally most robust to thermal stress. Although the heat tolerance of corals may be contingent on the Symbiodinium strain in hospite, our results highlight the complexity of interactions between symbiotic partners and a potential role for host factors in determining the physiological performance of reef corals. PMID:18577506

  10. General stress response signaling

    PubMed Central

    Huo, Yi-Xin; Rosenthal, Adam Z.; Gralla, Jay D.

    2008-01-01

    E. coli responds to stress by a combination of specific and general transcription signaling pathways. The general pathways typically require the master stress regulator sigma38 (rpoS). Here we show that the signaling from multiple stresses that relax DNA is processed by a non-conserved 8 amino acid tail of the sigma 38 C-terminal domain (CTD). By contrast, responses to stresses that accumulate potassium glutamate do not rely on this short tail, but still require the overall CTD. In vitro transcription and footprinting studies suggest that multiple stresses can target a poised RNA polymerase and activate it by unwrapping DNA from a nucleosome-like state, allowing the RNA polymerase to escape into productive mode. This transition can be accomplished by either the DNA relaxation or potassium glutamate accumulation that characterizes many stresses. PMID:18761624

  11. Role of heat shock protein Hsp25 in the response of the orofacial nuclei motor system to physiological stress

    NASA Technical Reports Server (NTRS)

    Murashov, A. K.; Talebian, S.; Wolgemuth, D. J.

    1998-01-01

    Although expression of the small heat shock protein family member Hsp25 has been previously observed in the central nervous system (CNS), both constitutively and upon induction, its function in the CNS remains far from clear. In the present study we have characterized the spatial pattern of expression of Hsp25 in the normal adult mouse brain as well as the changes in expression patterns induced by subjecting mice to experimental hyperthermia or hypoxia. Immunohistochemical analysis revealed a surprisingly restricted pattern of constitutive expression of Hsp25 in the brain, limited to the facial, trigeminal, ambiguus, hypoglossal and vagal motor nuclei of the brainstem. After hyperthermia or hypoxia treatment, significant increases in the levels of Hsp25 were observed in these same areas and also in fibers of the facial and trigeminal nerve tracts. Immunoblot analysis of protein lysates from brainstem also showed the same pattern of induction of Hsp25. Surprisingly, no other area in the brain showed expression of Hsp25, in either control or stressed animals. The highly restricted expression of Hsp25 implies that this protein may have a specific physiological role in the orofacial motor nuclei, which govern precise coordination between muscles of mastication and the pharynx, larynx, and face. Its rapid induction after stress further suggests that Hsp25 may serve as a specific molecular chaperone in the lower cholinergic motor neurons and along their fibers under conditions of stress or injury. Copyright 1998 Elsevier Science B.V.

  12. Characterization of Small RNAs Derived from tRNAs, rRNAs and snoRNAs and Their Response to Heat Stress in Wheat Seedlings

    PubMed Central

    Sun, Qixin; Yao, Yingyin

    2016-01-01

    Small RNAs (sRNAs) derived from non-coding RNAs (ncRNAs), such as tRNAs, rRNAs and snoRNAs, have been identified in various organisms. Several observations have indicated that cleavage of tRNAs and rRNAs is induced by various stresses. To clarify whether sRNAs in wheat derived from tRNAs (stRNAs), rRNAs (srRNAs) and snoRNAs (sdRNAs) are produced specifically in association with heat stress responses, we carried out a bioinformatic analysis of sRNA libraries from wheat seedlings and performed comparisons between control and high-temperature-treated samples to measure the differential abundance of stRNAs, srRNAs and sdRNAs. We found that the production of sRNAs from tRNAs, 5.8S rRNAs, and 28S rRNAs was more specific than that from 5S rRNAs and 18S rRNAs, and more than 95% of the stRNAs were processed asymmetrically from the 3’ or 5’ ends of mature tRNAs. We identified 333 stRNAs and 8,822 srRNAs that were responsive to heat stress. Moreover, the expression of stRNAs derived from tRNA-Val-CAC, tRNA-Thr-UGU, tRNA-Tyr-GUA and tRNA-Ser-UGA was not only up-regulated under heat stress but also induced by osmotic stress, suggesting that the increased cleavage of tRNAs might be a mechanism that developed in wheat seedlings to help them cope with adverse environmental conditions. PMID:26963812

  13. Fever, hyperthermia and the heat shock response.

    PubMed

    Singh, Ishwar S; Hasday, Jeffrey D

    2013-08-01

    The heat shock response is a highly conserved primitive response that is essential for survival against a wide range of stresses, including extremes of temperature. Fever is a more recently evolved response, during which organisms raise their core body temperature and temporarily subject themselves to thermal stress in the face of infections. The present review documents studies showing the potential overlap between the febrile response and the heat shock response and how both activate the same common transcriptional programme (although with different magnitudes) including the stress-activated transcription factor, heat shock factor-1, to modify host defences in the context of infection, inflammation and injury. The review focuses primarily on how hyperthermia within the febrile range that often accompanies infections and inflammation acts as a biological response modifier and modifies innate immune responses. The characteristic 2-3 °C increase in core body temperature during fever activates and utilises elements of the heat shock response pathway to modify cytokine and chemokine gene expression, cellular signalling and immune cell mobilisation to sites of inflammation, infection and injury. Interestingly, typical proinflammatory agonists such as Toll-like receptor agonists modify the heat shock-induced transcriptional programme and expression of HSP genes following co-exposure to febrile range hyperthermia or heat shock, suggesting a complex reciprocal regulation between the inflammatory pathway and the heat shock response pathway. PMID:23863046

  14. Heat stress and strain in exercise and sport.

    PubMed

    Brotherhood, John R

    2008-01-01

    Heat stress arising from the thermal environment is of concern to sports medicine and to sports administration because of the perceived risk of heat casualties, in particular heat stroke. Many sports organizations recommend environmental indices such as the WBGT for assessing risk and setting environmental limits for training and competition. But the limits are not justified by evidence. This article describes the nature of heat stress in sport and how it may be assessed objectively. Heat stress and the principal human responses to exercise heat stress are reviewed briefly. Metabolic heat production and the thermal environment provoke separate and largely independent physiological strains. Metabolic heat production drives body core temperature, and the thermal environment drives skin temperature; the combined stresses are integrated to drive sweat rate. Control of core temperature depends on adequate sweat production and the capacity of the environment to evaporate the sweat. The nature of exercise heat stress is demonstrated by rational analysis of the physical heat exchanges between the body and the environment. The principles of this analysis are applied to critical review of current practice in the assessment of heat stress in sport. The article concludes with discussion of research to establish methods for objective sport-specific assessment of heat stress. PMID:17997136

  15. Nutritional interventions to alleviate the negative consequences of heat stress.

    PubMed

    Rhoads, Robert P; Baumgard, Lance H; Suagee, Jessica K; Sanders, Sara R

    2013-05-01

    Energy metabolism is a highly coordinated process, and preferred fuel(s) differ among tissues. The hierarchy of substrate use can be affected by physiological status and environmental factors including high ambient temperature. Unabated heat eventually overwhelms homeothermic mechanisms resulting in heat stress, which compromises animal health, farm animal production, and human performance. Various aspects of heat stress physiology have been extensively studied, yet a clear understanding of the metabolic changes occurring at the cellular, tissue, and whole-body levels in response to an environmental heat load remains ill-defined. For reasons not yet clarified, circulating nonesterified fatty acid levels are reduced during heat stress, even in the presence of elevated stress hormones (epinephrine, glucagon, and cortisol), and heat-stressed animals often have a blunted lipolytic response to catabolic signals. Either directly because of or in coordination with this, animals experiencing environmental hyperthermia exhibit a shift toward carbohydrate use. These metabolic alterations occur coincident with increased circulating basal and stimulated plasma insulin concentrations. Limited data indicate that proper insulin action is necessary to effectively mount a response to heat stress and minimize heat-induced damage. Consistent with this idea, nutritional interventions targeting increased insulin action may improve tolerance and productivity during heat stress. Further research is warranted to uncover the effects of heat on parameters associated with energy metabolism so that more appropriate and effective treatment methodologies can be designed. PMID:23674792

  16. Heat shock factor 2 is a stress-responsive mediator of neuronal migration defects in models of fetal alcohol syndrome.

    PubMed

    El Fatimy, Rachid; Miozzo, Federico; Le Mouël, Anne; Abane, Ryma; Schwendimann, Leslie; Sabéran-Djoneidi, Délara; de Thonel, Aurélie; Massaoudi, Illiasse; Paslaru, Liliana; Hashimoto-Torii, Kazue; Christians, Elisabeth; Rakic, Pasko; Gressens, Pierre; Mezger, Valérie

    2014-01-01

    Fetal alcohol spectrum disorder (FASD) is a frequent cause of mental retardation. However, the molecular mechanisms underlying brain development defects induced by maternal alcohol consumption during pregnancy are unclear. We used normal and Hsf2-deficient mice and cell systems to uncover a pivotal role for heat shock factor 2 (HSF2) in radial neuronal migration defects in the cortex, a hallmark of fetal alcohol exposure. Upon fetal alcohol exposure, HSF2 is essential for the triggering of HSF1 activation, which is accompanied by distinctive post-translational modifications, and HSF2 steers the formation of atypical alcohol-specific HSF1-HSF2 heterocomplexes. This perturbs the in vivo binding of HSF2 to heat shock elements (HSEs) in genes that control neuronal migration in normal conditions, such as p35 or the MAPs (microtubule-associated proteins, such as Dclk1 and Dcx), and alters their expression. In the absence of HSF2, migration defects as well as alterations in gene expression are reduced. Thus, HSF2, as a sensor for alcohol stress in the fetal brain, acts as a mediator of the neuronal migration defects associated with FASD. PMID:25027850

  17. Heat shock factor 2 is a stress-responsive mediator of neuronal migration defects in models of fetal alcohol syndrome

    PubMed Central

    El Fatimy, Rachid; Miozzo, Federico; Le Mouël, Anne; Abane, Ryma; Schwendimann, Leslie; Sabéran-Djoneidi, Délara; de Thonel, Aurélie; Massaoudi, Illiasse; Paslaru, Liliana; Hashimoto-Torii, Kazue; Christians, Elisabeth; Rakic, Pasko; Gressens, Pierre; Mezger, Valérie

    2014-01-01

    Fetal alcohol spectrum disorder (FASD) is a frequent cause of mental retardation. However, the molecular mechanisms underlying brain development defects induced by maternal alcohol consumption during pregnancy are unclear. We used normal and Hsf2-deficient mice and cell systems to uncover a pivotal role for heat shock factor 2 (HSF2) in radial neuronal migration defects in the cortex, a hallmark of fetal alcohol exposure. Upon fetal alcohol exposure, HSF2 is essential for the triggering of HSF1 activation, which is accompanied by distinctive post-translational modifications, and HSF2 steers the formation of atypical alcohol-specific HSF1–HSF2 heterocomplexes. This perturbs the in vivo binding of HSF2 to heat shock elements (HSEs) in genes that control neuronal migration in normal conditions, such as p35 or the MAPs (microtubule-associated proteins, such as Dclk1 and Dcx), and alters their expression. In the absence of HSF2, migration defects as well as alterations in gene expression are reduced. Thus, HSF2, as a sensor for alcohol stress in the fetal brain, acts as a mediator of the neuronal migration defects associated with FASD. Subject Categories Development & Differentiation; Neuroscience PMID:25027850

  18. Incubation temperature alters thermal preference and response to heat stress of broiler chickens along the rearing phase.

    PubMed

    Morita, V S; Almeida, V R; Matos Junior, J B; Vicentini, T I; van den Brand, H; Boleli, I C

    2016-08-01

    The current study aimed to investigate whether embryonic temperature manipulation may alter thermal preference throughout the rearing phase of broiler chickens and how this manipulation may affect response to thermal challenge, metabolism, growth rate and feed intake rate. Eggs were exposed to a constant incubation temperature [machine temperatures: 36°C (Low), 37.5°C (Control), and 39°C (High); eggshell temperature of 37.4 ± 0.08°C, 37.8 ± 0.15°C, and 38.8 ± 0.33°C, respectively] from d 13 till hatching. Low treatment chickens showed lower plasma T3 and GH levels at d 1 of age and lower T3 level at d 42 of age compared to the Control treatment. Preferred ambient, rectal temperature, T4 level, growth rate, food intake rate, and response to thermal challenge were not altered in these chickens. On the other hand, High-treatment chickens exhibited high preferred ambient temperature and rectal temperature during the first 2 wk post-hatch, lower plasma T3 level at d 21 and 42 and a delayed increase in respiratory movement in response to thermal challenge compared to the Control treatment. However, chickens subjected to the Control and High treatments did not differ in T4 and GH level and performance. We conclude that exposure to high temperature during late embryonic development has long-lasting effects on the thermoregulatory system of broiler chickens by affecting the heat tolerance of these chickens. Moreover, the preferred ambient temperature of the chickens from heat-treated eggs correspond to those recommended for the strain under study, whereas for the cold-treated and control-chickens it was 1°C below, indicating that incubation temperature might have consequences on the ambient temperature chickens require during the rearing phase. PMID:26994196

  19. The yeast PH domain proteins Slm1 and Slm2 are targets of sphingolipid signaling during the response to heat stress.

    PubMed

    Daquinag, Alexes; Fadri, Maria; Jung, Sung Yun; Qin, Jun; Kunz, Jeannette

    2007-01-01

    The PH domain-containing proteins Slm1 and Slm2 were previously identified as effectors of the phosphatidylinositol-4,5-bisphosphate (PI4,5P(2)) and TORC2 signaling pathways. Here, we demonstrate that Slm1 and Slm2 are also targets of sphingolipid signaling during the heat shock response. We show that upon depletion of cellular sphingolipid levels, Slm1 function becomes essential for survival under heat stress. We further demonstrate that Slm proteins are regulated by a phosphorylation/dephosphorylation cycle involving the sphingolipid-activated protein kinases Pkh1 and Pkh2 and the calcium/calmodulin-dependent protein phosphatase calcineurin. By using a combination of mass spectrometry and mutational analysis, we identified serine residue 659 in Slm1 as a site of phosphorylation. Characterization of Slm1 mutants that mimic dephosphorylated and phosphorylated states demonstrated that phosphorylation at serine 659 is vital for survival under heat stress and promotes the proper polarization of the actin cytoskeleton. Finally, we present evidence that Slm proteins are also required for the trafficking of the raft-associated arginine permease Can1 to the plasma membrane, a process that requires sphingolipid synthesis and actin polymerization. Together with previous work, our findings suggest that Slm proteins are subject to regulation by multiple signals, including PI4,5P(2), TORC2, and sphingolipids, and may thus integrate inputs from different signaling pathways to temporally and spatially control actin polarization. PMID:17101780

  20. Stress Responses of Shewanella

    PubMed Central

    Yin, Jianhua; Gao, Haichun

    2011-01-01

    The shewanellae are ubiquitous in aquatic and sedimentary systems that are chemically stratified on a permanent or seasonal basis. In addition to their ability to utilize a diverse array of terminal electron acceptors, the microorganisms have evolved both common and unique responding mechanisms to cope with various stresses. This paper focuses on the response and adaptive mechanism of the shewanellae, largely based on transcriptional data. PMID:21912550

  1. Heat shock protein 90 (HSP90) inhibitors activate the heat shock factor 1 (HSF1) stress response pathway and improve glucose regulation in diabetic mice.

    PubMed

    Lee, Jee-Hyung; Gao, Jiaping; Kosinski, Penelope A; Elliman, Stephen J; Hughes, Thomas E; Gromada, Jesper; Kemp, Daniel M

    2013-01-18

    The cytoprotective stress response factor HSF1 regulates the transcription of the chaperone HSP70, which exhibits anti-inflammatory effects and improves insulin sensitivity. We tested the therapeutic potential of this pathway in rodent models of diabetes using pharmacological tools. Activation of the HSF1 pathway was achieved using potent inhibitors of the upstream regulatory protein, HSP90. Treatment with AUY922, a selective HSP90 inhibitor led to robust inhibition of JNK1 phosphorylation, cytoprotection and improved insulin signaling in cells, consistent with effects observed with HSP70 treatment. Chronic dosing with HSP90 inhibitors reversed hyperglycemia in the diabetic db/db mouse model, and improved insulin sensitivity in the diet-induced obese mouse model of insulin resistance, further supporting the concept that the HSF1 pathway is a potentially viable anti-diabetes target. PMID:23261432

  2. Water Replacement Schedules in Heat Stress

    ERIC Educational Resources Information Center

    Londeree, Ben R.; and others

    1969-01-01

    Although early ingestion of cold water appears to lead to greater relief from heat stress during physical exertion than late ingestion, this difference is reduced toward the end of an hour's work in high heat and humidity. (CK)

  3. The bacterial translation stress response

    PubMed Central

    Starosta, Agata L.; Lassak, Jürgen; Jung, Kirsten; Wilson, Daniel N.

    2014-01-01

    Throughout their life, bacteria need to sense and respond to environmental stress. Thus, such stress responses can require dramatic cellular reprogramming, both at the transcriptional as well as the translational level. This review focuses on the protein factors that interact with the bacterial translational apparatus in order to respond to and cope with different types of environmental stress. For example, the stringent factor RelA interacts with the ribosome to generate ppGpp under nutrient deprivation, whereas a variety of factors have been identified that bind to the ribosome under unfavorable growth conditions to shut-down (RelE, pY, RMF, HPF and EttA) or re-program (MazF, EF4 and BipA) translation. Additional factors have been identified that rescue ribosomes stalled due to stress-induced mRNA truncation (tmRNA, ArfA, ArfB), translation of unfavorable protein sequences (EF-P), heat shock induced subunit dissociation (Hsp15) or antibiotic inhibition (TetM, FusB). Understanding the mechanism of how the bacterial cell responds to stress will not only provide fundamental insight into translation regulation, but will also be an important step to identifying new targets for the development of novel antimicrobial agents. PMID:25135187

  4. Oxidative stress in deep scattering layers: Heat shock response and antioxidant enzymes activities of myctophid fishes thriving in oxygen minimum zones

    NASA Astrophysics Data System (ADS)

    Lopes, Ana Rita; Trübenbach, Katja; Teixeira, Tatiana; Lopes, Vanessa M.; Pires, Vanessa; Baptista, Miguel; Repolho, Tiago; Calado, Ricardo; Diniz, Mário; Rosa, Rui

    2013-12-01

    Diel vertical migrators, such as myctophid fishes, are known to encounter oxygen minimum zones (OMZ) during daytime in the Eastern Pacific Ocean and, therefore, have to cope with temperature and oxidative stress that arise while ascending to warmer, normoxic surface waters at night-time. The aim of this study was to investigate the antioxidant defense strategies and heat shock response (HSR) in two myctophid species, namely Triphoturus mexicanus and Benthosema panamense, at shallow and warm surface waters (21 kPa, 20-25 °C) and at hypoxic, cold (≤1 kPa, 10 °C) mesopelagic depths. More specifically, we quantified (i) heat shock protein concentrations (HSP70/HSC70) (ii) antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], and (iii) lipid peroxidation [malondialdehyde (MDA) levels]. HSP70/HSC70 levels increased in both myctophid species at warmer, well-oxygenated surface waters probably to prevent cellular damage (oxidative stress) due to increased oxygen demand under elevated temperatures and reactive oxygen species (ROS) formation. On the other hand, CAT and GST activities were augmented under hypoxic conditions, probably as preparatory response to a burst of oxyradicals during the reoxygenation phase (while ascending). SOD activity decreased under hypoxia in B. panamense, but was kept unchanged in T. mexicanus. MDA levels in B. panamense did not change between the surface and deep-sea conditions, whereas T. mexicanus showed elevated MDA and HSP70/HSC70 concentrations at warmer surface waters. This indicated that T. mexicanus seems to be not so well tuned to temperature and oxidative stress associated to diel vertical migrations. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how different species might respond to the impacts of environmental stressors (e.g. expanding mesopelagic hypoxia

  5. Antioxidant and photoprotective responses to elevated CO(2) and heat stress during holm oak regeneration by resprouting, evaluated with NIRS (near-infrared reflectance spectroscopy).

    PubMed

    Pintó-Marijuan, M; Joffre, R; Casals, I; De Agazio, M; Zacchini, M; García-Plazaola, J-I; Esteban, R; Aranda, X; Guàrdia, M; Fleck, I

    2013-01-01

    Photosynthetic, photoprotective and antioxidant responses during high temperature stress were determined in leaves of evergreen holm oak (Quercus ilex L.), the main species in Mediterranean forests, during resprouting under elevated CO(2) (750 μl·l(-1) ). Leaf chemicals, chloroplast pigments and non-enzymatic antioxidants were quantified in a single measurement using NIRS (near-infrared spectroscopy), a rapid and suitable method for ecophysiological purposes. Resprouts from plants grown under elevated CO(2) (RE) showed photosynthetic down-regulation, higher starch content and lower stomatal conductance, but similar stomatal density, than plants grown under current CO(2) concentrations (350 μl·l(-1) ) (RA). The photosynthetic sink reduction and need for more antioxidants and photoprotection in RE were reflected in an increased concentration of ascorbate (Asc) and phenolic compounds and in the contribution of the xanthophyll (Z/VAZ) and lutein epoxide cycles to excess energy dissipation as heat, and also reflected in chlorophyll fluorescence measurements. CO(2) assimilation parameters were stable from 25 to 35 °C in RE and RA, declining thereafter in RA in spite of a 2.3 °C lower leaf temperature. RE showed a more marked decline in photorespiration above 35 °C and less sensitive stomatal responses to high temperature stress than RA. During heat stress, RE had higher Asc, Z/VAZ and phenolics content, together with delayed enhancement of chloroplast lipophilic antioxidant compounds (carotenes and tocopherols). The high contribution of photoprotective systems and high temperature tolerance in resprouts developed under elevated CO(2) would mitigate the effect of photosynthesis acclimation during the regeneration of Q. ilex plants under climate change. PMID:22243620

  6. Effects of dietary selenium and vitamin E on immune response and biological blood parameters of broilers reared under thermoneutral or heat stress conditions

    NASA Astrophysics Data System (ADS)

    Habibian, Mahmood; Ghazi, Shahab; Moeini, Mohammad Mehdi; Abdolmohammadi, Alireza

    2014-07-01

    A study was conducted using 360 broiler chickens to evaluate the effects of dietary vitamin E (0, 125 and 250 mg/kg), selenium (Se, 0, 0.5 and 1 mg/kg), or their different combinations on immune response and blood biological parameters of broilers raised under either thermoneutral (TN, 23.9 °C constant) or heat stress (HS, 23.9 to 37 °C cycling) conditions. Humoral immunity was assessed by intravenous injection of 7 % sheep red blood cell (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Heterophil to lymphocyte (H/L) ratio also determined as an indicator of stress. Furthermore, at the end of the experiment, birds were bled for determination of some biological parameters. There was a significant reduction in body weight and feed intake, but the feed conversion ratio increased when the birds were exposed to HS ( P < 0.05). Body weight and feed intake were not influenced significantly by dietary vitamin E and Se ( P > 0.05), whereas feed conversion was improved significantly by 125 mg/kg vitamin E ( P < 0.05). The liver and lymphoid organ weights as well as IgM and IgG, antibody titers for primary and secondary antibody responses to SRBC were reduced significantly under HS ( P < 0.05). Heat stress also resulted in a significant increase in H/L ratio ( P < 0.05). Dietary vitamin E resulted in improvement of primary and secondary antibody responses both in TN and HS broilers ( P < 0.05). The HS birds also showed an improved antibody titer in secondary response with high concentration of Se ( P < 0.05). Vitamin E and Se had interactive effects on anti-SRBC titers; however, no consistent differences were found between dietary levels during the study. The H/L ratio decreased by feeding vitamin E at both levels either under HS or TN conditions ( P < 0.05). The serum concentrations of glucose, triglycerides, total cholesterol, and LDL-cholesterol were increased but serum HDL-cholesterol decreased in HS broilers ( P < 0.05).

  7. The surgically induced stress response.

    PubMed

    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

  8. Stress state of a plate heated by a heat source

    SciTech Connect

    Motovilovets, I.A.

    1995-11-01

    THis article presents the solution to a thermoelastic problem concerning the stress-strain of an infinite plate heated by a heat source. It is assumed that the temperature and the source of heat change linearly through the thickness of the plate. Errors made in [2,5,6] in the derivation of the thermoelastic equations of state are explained.

  9. Unraveling Regulation of the Small Heat Shock Proteins by the Heat Shock Factor HvHsfB2c in Barley: Its Implications in Drought Stress Response and Seed Development

    PubMed Central

    Reddy, Palakolanu Sudhakar; Kavi Kishor, Polavarapu B.; Seiler, Christiane; Kuhlmann, Markus; Eschen-Lippold, Lennart; Lee, Justin; Reddy, Malireddy K.; Sreenivasulu, Nese

    2014-01-01

    The rapid increase in heat shock proteins upon exposure to damaging stresses and during plant development related to desiccation events reveal their dual importance in plant development and stress tolerance. Genome-wide sequence survey identified 20 non-redundant small heat shock proteins (sHsp) and 22 heat shock factor (Hsf) genes in barley. While all three major classes (A, B, C) of Hsfs are localized in nucleus, the 20 sHsp gene family members are localized in different cell organelles like cytoplasm, mitochondria, plastid and peroxisomes. Hsf and sHsp members are differentially regulated during drought and at different seed developmental stages suggesting the importance of chaperone role under drought as well as seed development. In silico cis-regulatory motif analysis of Hsf promoters showed an enrichment with abscisic acid responsive cis-elements (ABRE), implying regulatory role of ABA in mediating transcriptional response of HvsHsf genes. Gene regulatory network analysis identified HvHsfB2c as potential central regulator of the seed-specific expression of several HvsHsps including 17.5CI sHsp. These results indicate that HvHsfB2c is co-expressed in the central hub of small Hsps and therefore it may be regulating the expression of several HvsHsp subclasses HvHsp16.88-CI, HvHsp17.5-CI and HvHsp17.7-CI. The in vivo relevance of binding specificity of HvHsfB2C transcription factor to HSE-element present in the promoter of HvSHP17.5-CI under heat stress exposure is confirmed by gel shift and LUC-reporter assays. Further, we isolated 477 bp cDNA from barley encoding a 17.5 sHsp polypeptide, which was predominantly upregulated under drought stress treatments and also preferentially expressed in developing seeds. Recombinant HvsHsp17.5-CI protein was expressed in E. coli and purified to homogeneity, which displayed in vitro chaperone activity. The predicted structural model of HvsHsp-17.5-CI protein suggests that the α-crystallin domain is evolutionarily highly

  10. Heat pipe transient response approximation

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.

    2002-01-01

    A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit can also be incorporated into this routine for heat pipes with more closely coupled condensers. The advantages and obvious limitations of this approach are discussed. For reference, a source code listing for the approximation appears at the end of this paper. .

  11. Heat Stress in Older Adults

    MedlinePlus

    ... well as young people to sudden changes in temperature. They are more likely to have a chronic ... that impair the body's ability to regulate its temperature or that inhibit perspiration. Heat Stroke Heat stroke ...

  12. Modeling heat stress under different environmental conditions.

    PubMed

    Carabaño, M J; Logar, B; Bormann, J; Minet, J; Vanrobays, M-L; Díaz, C; Tychon, B; Gengler, N; Hammami, H

    2016-05-01

    Renewed interest in heat stress effects on livestock productivity derives from climate change, which is expected to increase temperatures and the frequency of extreme weather events. This study aimed at evaluating the effect of temperature and humidity on milk production in highly selected dairy cattle populations across 3 European regions differing in climate and production systems to detect differences and similarities that can be used to optimize heat stress (HS) effect modeling. Milk, fat, and protein test day data from official milk recording for 1999 to 2010 in 4 Holstein populations located in the Walloon Region of Belgium (BEL), Luxembourg (LUX), Slovenia (SLO), and southern Spain (SPA) were merged with temperature and humidity data provided by the state meteorological agencies. After merging, the number of test day records/cows per trait ranged from 686,726/49,655 in SLO to 1,982,047/136,746 in BEL. Values for the daily average and maximum temperature-humidity index (THIavg and THImax) ranges for THIavg/THImax were largest in SLO (22-74/28-84) and shortest in SPA (39-76/46-83). Change point techniques were used to determine comfort thresholds, which differed across traits and climatic regions. Milk yield showed an inverted U-shaped pattern of response across the THI scale with a HS threshold around 73 THImax units. For fat and protein, thresholds were lower than for milk yield and were shifted around 6 THI units toward larger values in SPA compared with the other countries. Fat showed lower HS thresholds than protein traits in all countries. The traditional broken line model was compared with quadratic and cubic fits of the pattern of response in production to increasing heat loads. A cubic polynomial model allowing for individual variation in patterns of response and THIavg as heat load measure showed the best statistical features. Higher/lower producing animals showed less/more persistent production (quantity and quality) across the THI scale. The

  13. Increased extracellular heat shock protein 90α in severe sepsis and SIRS associated with multiple organ failure and related to acute inflammatory-metabolic stress response in children

    PubMed Central

    Fitrolaki, Michaela-Diana; Dimitriou, Helen; Venihaki, Maria; Katrinaki, Marianna; Ilia, Stavroula; Briassoulis, George

    2016-01-01

    Abstract Mammalian heat-shock-protein (HSP) 90α rapidly responses to environmental insults. We examined the hypothesis that not only serum HSP72 but also HSP90α is increased in the systemic inflammatory response syndrome (SIRS), severe-sepsis (SS), and/or sepsis (S) compared to healthy children (H); we assessed HSP90α relation to (a) multiple organ system failure (MOSF) and (b) inflammatory-metabolic response and severity of illness. A total of 65 children with S, SS, or SIRS and 25 H were included. ELISA was used to evaluate extracellular HSP90α and HSP72, chemiluminescence interleukins (ILs), flow-cytometry neutrophil-CD64 (nCD64)-expression. HSP90α, along with HSP72, were dramatically increased among MOSF patients. Patients in septic groups and SIRS had elevated HSP90α compared to H (P < 0.01). HSP90α was independently related to predicted death rate and severity of illness; positively to HSP72, nCD64, ILs, length of stay, days on ventilator, and fever; negatively to HDL and LDL (P < 0.05). The HSP72 was increased in SS/S and related negatively to HDL and LDL (P < 0.05). Serum HSP90α is markedly elevated in children with severe sepsis and is associated with MOSF. Better than the HSP72, also increased in SS, SIRS, and MOSF, HSP90α is related to the inflammatory stress, fever, outcome endpoints, and predicted mortality and inversely related to the low-LDL/low-HDL stress metabolic pattern. PMID:27583886

  14. Increased extracellular heat shock protein 90α in severe sepsis and SIRS associated with multiple organ failure and related to acute inflammatory-metabolic stress response in children.

    PubMed

    Fitrolaki, Michaela-Diana; Dimitriou, Helen; Venihaki, Maria; Katrinaki, Marianna; Ilia, Stavroula; Briassoulis, George

    2016-08-01

    Mammalian heat-shock-protein (HSP) 90α rapidly responses to environmental insults. We examined the hypothesis that not only serum HSP72 but also HSP90α is increased in the systemic inflammatory response syndrome (SIRS), severe-sepsis (SS), and/or sepsis (S) compared to healthy children (H); we assessed HSP90α relation to (a) multiple organ system failure (MOSF) and (b) inflammatory-metabolic response and severity of illness.A total of 65 children with S, SS, or SIRS and 25 H were included. ELISA was used to evaluate extracellular HSP90α and HSP72, chemiluminescence interleukins (ILs), flow-cytometry neutrophil-CD64 (nCD64)-expression.HSP90α, along with HSP72, were dramatically increased among MOSF patients. Patients in septic groups and SIRS had elevated HSP90α compared to H (P < 0.01). HSP90α was independently related to predicted death rate and severity of illness; positively to HSP72, nCD64, ILs, length of stay, days on ventilator, and fever; negatively to HDL and LDL (P < 0.05). The HSP72 was increased in SS/S and related negatively to HDL and LDL (P < 0.05).Serum HSP90α is markedly elevated in children with severe sepsis and is associated with MOSF. Better than the HSP72, also increased in SS, SIRS, and MOSF, HSP90α is related to the inflammatory stress, fever, outcome endpoints, and predicted mortality and inversely related to the low-LDL/low-HDL stress metabolic pattern. PMID:27583886

  15. Dnajb8, a Member of the Heat Shock Protein 40 Family Has a Role in the Tumor Initiation and Resistance to Docetaxel but Is Dispensable for Stress Response

    PubMed Central

    Yamashita, Masamichi; Hirohashi, Yoshihiko; Torigoe, Toshihiko; Kusumoto, Hiroki; Murai, Aiko; Imagawa, Tomohiro; Sato, Noriyuki

    2016-01-01

    Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are defined by their abilities of tumor initiation, self-renewal and differentiation. In a previous study, we showed by gene knockdown using siRNA and gene overexpression experiments that Dnaj (Hsp40) homolog, subfamily B, member 8 (DNAJB8), a role in the maintenance, of renal cell carcinoma CSCs/CICs. In the present study, we established Dnajb8 knockout (KO) renal cell carcinoma (RCC) line cells (RenCa cells) and analyzed the cells to confirm the function of Dnajb8 in RCC CSCs/CICs. Dnajb8 KO cells showed reduced ratios of side population cells and reduced sphere forming ability. An in vivo single cell tumor initiation assay revealed that the numbers of CSCs/CICs were 3 in 4 wild-type RenCa cells and 1 in 4 Dnajb8 KO cells. Dnajb8 KO cells showed sensitivity to Docetaxel. On the other hand, Dnajb8 KO cells did not show any sensitivities to stresses including low pH, low glucose, heat shock and sensitivity to cisplatin. The results indicate that Dnajb8 has a role in tumor initiation, side population ratio and sphere formation but it is dispensable for stress responses. PMID:26751205

  16. Dnajb8, a Member of the Heat Shock Protein 40 Family Has a Role in the Tumor Initiation and Resistance to Docetaxel but Is Dispensable for Stress Response.

    PubMed

    Yamashita, Masamichi; Hirohashi, Yoshihiko; Torigoe, Toshihiko; Kusumoto, Hiroki; Murai, Aiko; Imagawa, Tomohiro; Sato, Noriyuki

    2016-01-01

    Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are defined by their abilities of tumor initiation, self-renewal and differentiation. In a previous study, we showed by gene knockdown using siRNA and gene overexpression experiments that Dnaj (Hsp40) homolog, subfamily B, member 8 (DNAJB8), a role in the maintenance, of renal cell carcinoma CSCs/CICs. In the present study, we established Dnajb8 knockout (KO) renal cell carcinoma (RCC) line cells (RenCa cells) and analyzed the cells to confirm the function of Dnajb8 in RCC CSCs/CICs. Dnajb8 KO cells showed reduced ratios of side population cells and reduced sphere forming ability. An in vivo single cell tumor initiation assay revealed that the numbers of CSCs/CICs were 3 in 4 wild-type RenCa cells and 1 in 4 Dnajb8 KO cells. Dnajb8 KO cells showed sensitivity to Docetaxel. On the other hand, Dnajb8 KO cells did not show any sensitivities to stresses including low pH, low glucose, heat shock and sensitivity to cisplatin. The results indicate that Dnajb8 has a role in tumor initiation, side population ratio and sphere formation but it is dispensable for stress responses. PMID:26751205

  17. Systems-wide analysis of acclimation responses to long-term heat stress and recovery in the photosynthetic model organism Chlamydomonas reinhardtii.

    PubMed

    Hemme, Dorothea; Veyel, Daniel; Mühlhaus, Timo; Sommer, Frederik; Jüppner, Jessica; Unger, Ann-Katrin; Sandmann, Michael; Fehrle, Ines; Schönfelder, Stephanie; Steup, Martin; Geimer, Stefan; Kopka, Joachim; Giavalisco, Patrick; Schroda, Michael

    2014-11-01

    We applied a top-down systems biology approach to understand how Chlamydomonas reinhardtii acclimates to long-term heat stress (HS) and recovers from it. For this, we shifted cells from 25 to 42°C for 24 h and back to 25°C for ≥8 h and monitored abundances of 1856 proteins/protein groups, 99 polar and 185 lipophilic metabolites, and cytological and photosynthesis parameters. Our data indicate that acclimation of Chlamydomonas to long-term HS consists of a temporally ordered, orchestrated implementation of response elements at various system levels. These comprise (1) cell cycle arrest; (2) catabolism of larger molecules to generate compounds with roles in stress protection; (3) accumulation of molecular chaperones to restore protein homeostasis together with compatible solutes; (4) redirection of photosynthetic energy and reducing power from the Calvin cycle to the de novo synthesis of saturated fatty acids to replace polyunsaturated ones in membrane lipids, which are deposited in lipid bodies; and (5) when sinks for photosynthetic energy and reducing power are depleted, resumption of Calvin cycle activity associated with increased photorespiration, accumulation of reactive oxygen species scavengers, and throttling of linear electron flow by antenna uncoupling. During recovery from HS, cells appear to focus on processes allowing rapid resumption of growth rather than restoring pre-HS conditions. PMID:25415976

  18. Systems-Wide Analysis of Acclimation Responses to Long-Term Heat Stress and Recovery in the Photosynthetic Model Organism Chlamydomonas reinhardtii[W][OPEN

    PubMed Central

    Hemme, Dorothea; Veyel, Daniel; Mühlhaus, Timo; Sommer, Frederik; Jüppner, Jessica; Unger, Ann-Katrin; Sandmann, Michael; Fehrle, Ines; Schönfelder, Stephanie; Steup, Martin; Geimer, Stefan; Kopka, Joachim; Giavalisco, Patrick; Schroda, Michael

    2014-01-01

    We applied a top-down systems biology approach to understand how Chlamydomonas reinhardtii acclimates to long-term heat stress (HS) and recovers from it. For this, we shifted cells from 25 to 42°C for 24 h and back to 25°C for ≥8 h and monitored abundances of 1856 proteins/protein groups, 99 polar and 185 lipophilic metabolites, and cytological and photosynthesis parameters. Our data indicate that acclimation of Chlamydomonas to long-term HS consists of a temporally ordered, orchestrated implementation of response elements at various system levels. These comprise (1) cell cycle arrest; (2) catabolism of larger molecules to generate compounds with roles in stress protection; (3) accumulation of molecular chaperones to restore protein homeostasis together with compatible solutes; (4) redirection of photosynthetic energy and reducing power from the Calvin cycle to the de novo synthesis of saturated fatty acids to replace polyunsaturated ones in membrane lipids, which are deposited in lipid bodies; and (5) when sinks for photosynthetic energy and reducing power are depleted, resumption of Calvin cycle activity associated with increased photorespiration, accumulation of reactive oxygen species scavengers, and throttling of linear electron flow by antenna uncoupling. During recovery from HS, cells appear to focus on processes allowing rapid resumption of growth rather than restoring pre-HS conditions. PMID:25415976

  19. Effect of prenatal temperature conditioning of laying hen embryos: Hatching, live performance and response to heat and cold stress during laying period.

    PubMed

    Kamanli, S; Durmuş, I; Yalçın, S; Yıldırım, U; Meral, Ö

    2015-07-01

    This study was designed to determine the effect of prenatal temperature conditioning on hatching and live performance of laying chickens, and response to heat and cold stress during laying period. A total of 3600 eggs obtained from ATAK-S brown parent stock were incubated at control (37.5°C, CONT-Inc), cyclic low (36.5°C/6h/d from 10 to 18d of incubation, LOW-Inc) or high (38.5°C/6h/d from 10-18d of incubation, HIGH-Inc) incubation temperatures. Hatched chicks per incubation temperature were reared under standard rearing conditions up to 26wk. From 27 to 30wk, hens from each incubation temperature were divided into 3 environmentally controlled rooms and reared at control (20±2°C, CONT-Room), low (12±2°C, COLDS) or high (32±2°C, HEATS) temperatures. Hatching performance, body weight, egg production, and plasma triiodothyronine (T3) and thyroxine (T4) levels and oxidant and antioxidant activities were evaluated. The highest hatchability was for LOW-Inc chicks while HIGH-Inc chick had similar hatchability to CONT-Inc. There was no effect of incubation temperatures on plasma MDA, GSH-Px, activities and T4 concentrations on day of hatch. LOW- Inc chicks had higher SOD activities and T3 concentrations compared to the other groups. Although chick weight was similar among incubation temperature groups, CONT-Inc chicks were heavier than those cyclic incubation temperature groups until 12wk of age. Incubation temperature had no effect on sexual maturity age and weight and egg production of laying hens. From 27 to 30wk, regardless of incubation temperature, HEATS hens lost weight from day 0 to 10, had the highest cloacal temperatures and lowest feed consumption and egg production while COLDS hens had the lowest cloacal temperatures. At day 5, T4 level was higher in LOW-Inc hens at COLDS but it was higher in HIGH-Inc hens at HEATS compared to CONT-Inc. These data may suggest a modification in thyroid activity of hens that were conditioned during the incubation period

  20. Transcriptome Profiles of Populus euphratica upon Heat Shock stress

    PubMed Central

    Chen, Jinhuan; Yin, Weilun; Xia, Xinli

    2014-01-01

    Heat stress, which strongly affects plant performance and often results in reduced vegetative growth and yields depression, has become an increasingly serious global problem. Populus euphratica Oliv. which has been considered as a tree model for the study of plant response to abiotic stresses, could be resistant to an extremely wide environmental temperature range (–40 °C to 45 °C). Previous study is mainly focused on its gene regulation upon drought and salt stress. However, little is known about gene regulation at the global transcriptome level upon heat stress. To understand the gene network controlling heat stress in P. euphratica, a transcriptome sequencing using Illumina Hiseq 2000 was performed to generate a 10 gigabases depth for each sample in the tissue of leaf. 119,573 unigeneswere generated with an average length of 474 bp. Approximately 49,605 (41.49%) unigenes exhibited significantly different expressions between two libraries. Among these unigenes, 11,165 (9.34%) were upregulated and 38,440 (32.15%) were down regulated. Heat shock proteins classified as molecular chaperones showed a significant percentage (1.13%) in the up regulated group. Heat responsive genes, such as polyubiquitins, were over expressed in heat treated sample. GO enrichment analysis revealed that the Go terms for differentially expressed unigenes were significantly enriched in hormone-mediated signal, biological process regulation and metabolic process regulation. Our data revealed a global transcriptome picture of P. euphratica in response to heat shock. The identified potential heat stress-related transcripts can be used to infer the gene regulation networks underlying the molecular mechanisms of heat response in P. euphratica. PMID:25435796

  1. Mechanisms of orthostatic intolerance during heat stress.

    PubMed

    Schlader, Zachary J; Wilson, Thad E; Crandall, Craig G

    2016-04-01

    Heat stress profoundly and unanimously reduces orthostatic tolerance. This review aims to provide an overview of the numerous and multifactorial mechanisms by which this occurs in humans. Potential causal factors include changes in arterial and venous vascular resistance and blood distribution, and the modulation of cardiac output, all of which contribute to the inability to maintain cerebral perfusion during heat and orthostatic stress. A number of countermeasures have been established to improve orthostatic tolerance during heat stress, which alleviate heat stress induced central hypovolemia (e.g., volume expansion) and/or increase peripheral vascular resistance (e.g., skin cooling). Unfortunately, these countermeasures can often be cumbersome to use with populations prone to syncopal episodes. Identifying the mechanisms of inter-individual differences in orthostatic intolerance during heat stress has proven elusive, but could provide greater insights into the development of novel and personalized countermeasures for maintaining or improving orthostatic tolerance during heat stress. This development will be especially impactful in occuational settings and clinical situations that present with orthostatic intolerance and/or central hypovolemia. Such investigations should be considered of vital importance given the impending increased incidence of heat events, and associated cardiovascular challenges that are predicted to occur with the ensuing changes in climate. PMID:26723547

  2. Heat stress in grapevine: the pros and cons of acclimation.

    PubMed

    Carvalho, Luísa C; Coito, João L; Colaço, Silvana; Sangiogo, Maurício; Amâncio, Sara

    2015-04-01

    Heat stress is a major limiting factor of grapevine production and quality. Acclimation and recovery are essential to ensure plant survival, and the recovery mechanisms can be independent of the heat response mechanisms. An experimental set up with and without acclimation to heat followed by recovery [stepwise acclimation and recovery (SAR) and stepwise recovery (SR), respectively] was applied to two grapevine varieties, Touriga Nacional (TN), and Trincadeira (TR), with different tolerance to abiotic stress. Major differences were found between leaves of SAR and SR, especially after recovery; in SAR, almost all parameters returned to basal levels while in SR they remained altered. Acclimation led to a swifter and short-term antioxidative response, affecting the plant to a lesser extent than SR. Significant differences were found among varieties: upon stress, TN significantly increased ascorbate and glutathione reduction levels, boosting the cell's redox-buffering capacity, while TR needed to synthesize both metabolites, its response being insufficient to keep the redox state at working levels. TR was affected by stress for a longer period and the up-regulation pattern of antioxidative stress genes was more obvious. In TN, heat shock proteins were significantly induced, but the canonical heat-stress gene signature was not evident probably because no shutdown of the housekeeping metabolism was needed. PMID:25211707

  3. A virtual rat for simulating environmental and exertional heat stress.

    PubMed

    Rakesh, Vineet; Stallings, Jonathan D; Reifman, Jaques

    2014-12-01

    Severe cases of environmental or exertional heat stress can lead to varying degrees of organ dysfunction. To understand heat-injury progression and develop efficient management and mitigation strategies, it is critical to determine the thermal response in susceptible organs under different heat-stress conditions. To this end, we used our previously published virtual rat, which is capable of computing the spatiotemporal temperature distribution in the animal, and extended it to simulate various heat-stress scenarios, including 1) different environmental conditions, 2) exertional heat stress, 3) circadian rhythm effect on the thermal response, and 4) whole body cooling. Our predictions were consistent with published in vivo temperature measurements for all cases, validating our simulations. We observed a differential thermal response in the organs, with the liver experiencing the highest temperatures for all environmental and exertional heat-stress cases. For every 3°C rise in the external temperature from 40 to 46°C, core and organ temperatures increased by ∼0.8°C. Core temperatures increased by 2.6 and 4.1°C for increases in exercise intensity from rest to 75 and 100% of maximal O2 consumption, respectively. We also found differences as large as 0.8°C in organ temperatures for the same heat stress induced at different times during the day. Even after whole body cooling at a relatively low external temperature (1°C for 20 min), average organ temperatures were still elevated by 2.3 to 2.5°C compared with normothermia. These results can be used to optimize experimental protocol designs, reduce the amount of animal experimentation, and design and test improved heat-stress prevention and management strategies. PMID:25277741

  4. Molecular Cloning and mRNA Expression of Heat Shock Protein Genes and Their Response to Cadmium Stress in the Grasshopper Oxya chinensis

    PubMed Central

    Zhang, Yuping; Liu, Yaoming; Zhang, Jianzhen; Guo, Yaping; Ma, Enbo

    2015-01-01

    Heat shock proteins (Hsps) are highly conserved molecular chaperones that are synthesized in response to stress. In this study, we cloned the full-length sequences of the Grp78 (glucose-regulated protein 78), Hsp70, Hsp90, and Hsp40 genes from the Chinese rice grasshopper Oxya chinensis. The full-length cDNA sequences of OcGrp78, OcHsp70, OcHsp90, and OcHsp40 contain open reading frames of 1947, 1920, 2172, and 1042 bp that encode proteins of 649, 640, 724, and 347 amino acids, respectively. Fluorescent real-time quantitative PCR (RT-qPCR) was performed to quantify the relative transcript levels of these Hsp genes in different tissues and developmental stages. The mRNAs encoding these four Hsp genes were present at all developmental stages and in all tissues examined but were expressed at varying levels. Additionally, we investigated the mRNA expression profiles of these four Hsps in O. chinensis subjected to Cadmium (Cd) stress. OcGrp78, OcHsp70, OcHsp90, and OcHsp40 mRNA expression was induced under acute Cd stress; the levels reached a maximum within a short time (6 h), were reduced significantly at 12 h, and were lowered to or below control levels by 48 h. Regarding induction efficiency, OcHsp70 was the most sensitive gene to acute Cd stress. Chronic Cd exposure showed that dietary Cd treatment induced increased OcGrp78, OcHsp90, and OcHsp40 expression. However, dietary Cd induced a significant reduction of OcHsp70 expression. In the period tested, no significant difference in the mortality of the grasshoppers was observed. Our results suggest that these four Hsps genes, especially OcHsp70, are sensitive to acute Cd stress and could be used as molecular markers for toxicology studies. However, our results also indicate that OcHsp70 is not suitable for use as a molecular marker of chronic Cd contamination. PMID:26135744

  5. Molecular Cloning and mRNA Expression of Heat Shock Protein Genes and Their Response to Cadmium Stress in the Grasshopper Oxya chinensis.

    PubMed

    Zhang, Yuping; Liu, Yaoming; Zhang, Jianzhen; Guo, Yaping; Ma, Enbo

    2015-01-01

    Heat shock proteins (Hsps) are highly conserved molecular chaperones that are synthesized in response to stress. In this study, we cloned the full-length sequences of the Grp78 (glucose-regulated protein 78), Hsp70, Hsp90, and Hsp40 genes from the Chinese rice grasshopper Oxya chinensis. The full-length cDNA sequences of OcGrp78, OcHsp70, OcHsp90, and OcHsp40 contain open reading frames of 1947, 1920, 2172, and 1042 bp that encode proteins of 649, 640, 724, and 347 amino acids, respectively. Fluorescent real-time quantitative PCR (RT-qPCR) was performed to quantify the relative transcript levels of these Hsp genes in different tissues and developmental stages. The mRNAs encoding these four Hsp genes were present at all developmental stages and in all tissues examined but were expressed at varying levels. Additionally, we investigated the mRNA expression profiles of these four Hsps in O. chinensis subjected to Cadmium (Cd) stress. OcGrp78, OcHsp70, OcHsp90, and OcHsp40 mRNA expression was induced under acute Cd stress; the levels reached a maximum within a short time (6 h), were reduced significantly at 12 h, and were lowered to or below control levels by 48 h. Regarding induction efficiency, OcHsp70 was the most sensitive gene to acute Cd stress. Chronic Cd exposure showed that dietary Cd treatment induced increased OcGrp78, OcHsp90, and OcHsp40 expression. However, dietary Cd induced a significant reduction of OcHsp70 expression. In the period tested, no significant difference in the mortality of the grasshoppers was observed. Our results suggest that these four Hsps genes, especially OcHsp70, are sensitive to acute Cd stress and could be used as molecular markers for toxicology studies. However, our results also indicate that OcHsp70 is not suitable for use as a molecular marker of chronic Cd contamination. PMID:26135744

  6. Immune responses and stress resistance in red sea bream, Pagrus major, after oral administration of heat-killed Lactobacillus plantarum and vitamin C.

    PubMed

    Dawood, Mahmoud A O; Koshio, Shunsuke; Ishikawa, Manabu; Yokoyama, Saichiro

    2016-07-01

    The present study evaluated the interactive benefits of dietary administration of heat-killed Lactobacillus plantarum (LP) and vitamin C (VC) on the growth, oxidative status and immune response of red sea bream (Pagrus major). A diet without LP and VC supplements was employed as a control diet. Four other test diets with 0 or 1 g LP kg(-1) combined with 0.5 or 1 g VC kg(-1) (2 × 2 factorial design) were fed to red sea bream (2 ± 0.01 g) for 56 days. A significant interaction was found between LP and VC on final body weight (FNW), weight gain (WG), hematocrit (HCT), serum bactericidal (BA) and lysozyme (LZY) activities, mucus LZY and peroxidase (PA) activities, nitro blue tetrazolium (NBT), catalase, mucus secretion and tolerance against low salinity stress test (LT50) (P < 0.05). In addition, FNW, WG, specific growth rate, feed and protein efficiency ratio, serum (BA, LZY, PA and NBT), mucus (LZY and PA), superoxide dismutase, malondialdehyde and mucus secretion were significantly affected by either LP or VC (P < 0.05). Furthermore, only LP was a significant factor on survival, plasma total cholesterol, mucus BA and alternative complement pathway (P < 0.05). However, VC supplementation affected on HCT and LT50. Interestingly, fish fed with both LP at 1 g kg(-1) diet with VC at 0.5 or 1 g kg(-1) diet showed higher growth, humoral and mucosal immune responses, anti-oxidative status, mucus secretion and LT50 as well as decreased plasma, triglyceride and total cholesterol levels than the fish fed control diet (P < 0.05). These results demonstrated that dietary LP and VC had a significant interaction for red sea bream with the capability of improving growth performance and enhancing stress resistance by immunomodulation. PMID:27095173

  7. Staphylococcal response to oxidative stress

    PubMed Central

    Gaupp, Rosmarie; Ledala, Nagender; Somerville, Greg A.

    2012-01-01

    Staphylococci are a versatile genus of bacteria that are capable of causing acute and chronic infections in diverse host species. The success of staphylococci as pathogens is due in part to their ability to mitigate endogenous and exogenous oxidative and nitrosative stress. Endogenous oxidative stress is a consequence of life in an aerobic environment; whereas, exogenous oxidative and nitrosative stress are often due to the bacteria's interaction with host immune systems. To overcome the deleterious effects of oxidative and nitrosative stress, staphylococci have evolved protection, detoxification, and repair mechanisms that are controlled by a network of regulators. In this review, we summarize the cellular targets of oxidative stress, the mechanisms by which staphylococci sense oxidative stress and damage, oxidative stress protection and repair mechanisms, and regulation of the oxidative stress response. When possible, special attention is given to how the oxidative stress defense mechanisms help staphylococci control oxidative stress in the host. PMID:22919625

  8. Heat Shock Protein 70 and 90 Genes in the Harmful Dinoflagellate Cochlodinium polykrikoides: Genomic Structures and Transcriptional Responses to Environmental Stresses

    PubMed Central

    Guo, Ruoyu; Youn, Seok Hyun; Ki, Jang-Seu

    2015-01-01

    The marine dinoflagellate Cochlodinium polykrikoides is responsible for harmful algal blooms in aquatic environments and has spread into the world's oceans. As a microeukaryote, it seems to have distinct genomic characteristics, like gene structure and regulation. In the present study, we characterized heat shock protein (HSP) 70/90 of C. polykrikoides and evaluated their transcriptional responses to environmental stresses. Both HSPs contained the conserved motif patterns, showing the highest homology with those of other dinoflagellates. Genomic analysis showed that the CpHSP70 had no intron but was encoded by tandem arrangement manner with separation of intergenic spacers. However, CpHSP90 had one intron in the coding genomic regions, and no intergenic region was found. Phylogenetic analyses of separate HSPs showed that CpHSP70 was closely related with the dinoflagellate Crypthecodinium cohnii and CpHSP90 with other Gymnodiniales in dinoflagellates. Gene expression analyses showed that both HSP genes were upregulated by the treatments of separate algicides CuSO4 and NaOCl; however, they displayed downregulation pattern with PCB treatment. The transcription of CpHSP90 and CpHSP70 showed similar expression patterns under the same toxicant treatment, suggesting that both genes might have cooperative functions for the toxicant induced gene regulation in the dinoflagellate. PMID:26064872

  9. The Surgically Induced Stress Response

    PubMed Central

    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

  10. Protective clothing and heat stress.

    PubMed

    Holmér, I

    1995-01-01

    The high level of protection required by protective clothing (PPC) severely impedes heat exchange by sweat evaporation. As a result work associated with wearing PPC, particularly in hot environments, implies considerable physiological strain and may render workers exhausted in a short time. Current methods of describing evaporative heat exchange with PPC are insufficient, will overestimate evaporative heat loss and should not be recommended. More reliable measures of the resistance to evaporative heat transfer by PPC should be developed and standardized. Direct measurements of evaporative resistance of PPC may be carried. However, a more promising method appears to be the definition of evaporative resistance on the basis of the icl-index for the fabric layers. The icl-index is a permeation efficiency ratio, which in combination with clothing insulation determines the evaporative heat transfer. Current methods should be further developed to account for effects of moisture condensation and microclimate ventilation. PMID:7875118

  11. Biophysical aspects of human thermoregulation during heat stress.

    PubMed

    Cramer, Matthew N; Jay, Ollie

    2016-04-01

    Humans maintain a relatively constant core temperature through the dynamic balance between endogenous heat production and heat dissipation to the surrounding environment. In response to metabolic or environmental disturbances to heat balance, the autonomic nervous system initiates cutaneous vasodilation and eccrine sweating to facilitate higher rates of dry (primarily convection and radiation) and evaporative transfer from the body surface; however, absolute heat losses are ultimately governed by the properties of the skin and the environment. Over the duration of a heat exposure, the cumulative imbalance between heat production and heat dissipation leads to body heat storage, but the consequent change in core temperature, which has implications for health and safety in occupational and athletic settings particularly among certain clinical populations, involves a complex interaction between changes in body heat content and the body's morphological characteristics (mass, surface area, and tissue composition) that collectively determine the body's thermal inertia. The aim of this review is to highlight the biophysical aspects of human core temperature regulation by outlining the principles of human energy exchange and examining the influence of body morphology during exercise and environmental heat stress. An understanding of the biophysical factors influencing core temperature will enable researchers and practitioners to better identify and treat individuals/populations most vulnerable to heat illness and injury during exercise and extreme heat events. Further, appropriate guidelines may be developed to optimize health, safety, and work performance during heat stress. PMID:26971392

  12. Thermoregulatory responses of Holstein and Brown Swiss Heat-Stressed dairy cows to two different cooling systems

    NASA Astrophysics Data System (ADS)

    Correa-Calderon, Abelardo; Armstrong, Dennis; Ray, Donald; DeNise, Sue; Enns, Mark; Howison, Christine

    . Thirty-seven Holstein and 26 Brown Swiss dairy cows were used to evaluate the effect of two different cooling systems on physiological and hormonal responses during the summer. A control group of cows had access only to shade (C). A second group was cooled with spray and fans (S/F) and the third group was under an evaporative cooling system called Korral Kool (KK). The maximum temperature humidity index during the trial was from 73 to 85. Rectal temperatures and respiration rates of the C group were higher (P < 0.05) than those of the S/F and KK groups in both Holstein and Brown Swiss cows. Triiodothyronine levels in milk were higher (P < 0.05) in the KK group than in the S/F and C groups, while cortisol levels were lower (P < 0.05) in the C group than in S/F and KK. There was no significant difference in the hormonal response of the two breeds. These results demonstrate that both cooling systems may be used increase the comfort of Holstein and Brown Swiss cows during summer in hot, dry climates.

  13. Cardiovascular function in the heat-stressed human.

    PubMed

    Crandall, C G; González-Alonso, J

    2010-08-01

    Heat stress, whether passive (i.e. exposure to elevated environmental temperatures) or via exercise, results in pronounced cardiovascular adjustments that are necessary for adequate temperature regulation as well as perfusion of the exercising muscle, heart and brain. The available data suggest that generally during passive heat stress baroreflex control of heart rate and sympathetic nerve activity are unchanged, while baroreflex control of systemic vascular resistance may be impaired perhaps due to attenuated vasoconstrictor responsiveness of the cutaneous circulation. Heat stress improves left ventricular systolic function, evidenced by increased cardiac contractility, thereby maintaining stroke volume despite large reductions in ventricular filling pressures. Heat stress-induced reductions in cerebral perfusion likely contribute to the recognized effect of this thermal condition in reducing orthostatic tolerance, although the mechanism(s) by which this occurs is not completely understood. The combination of intense whole-body exercise and environmental heat stress or dehydration-induced hyperthermia results in significant cardiovascular strain prior to exhaustion, which is characterized by reductions in cardiac output, stroke volume, arterial pressure and blood flow to the brain, skin and exercising muscle. These alterations in cardiovascular function and regulation late in heat stress/dehydration exercise might involve the interplay of both local and central reflexes, the contribution of which is presently unresolved. PMID:20345414

  14. Circulatory endotoxin concentration and cytokine profile in response to exertional-heat stress during a multi-stage ultra-marathon competition.

    PubMed

    Gill, Samantha K; Teixeira, Ana; Rama, Luis; Prestes, Jonato; Rosado, Fatima; Hankey, Joanne; Scheer, Volker; Hemmings, Krystal; Ansley-Robson, Paula; Costa, Ricardo J S

    2015-01-01

    Exertional-heat stress has the potential to disturb intestinal integrity, leading to enhanced permeability of enteric pathogenic micro-organisms and associated clinical manifestations. The study aimed to determine the circulatory endotoxin concentration and cytokine profile of ultra-endurance runners (UER, n=19) and a control group (CON, n=12) during a five stage 230km ultra-marathon (mean ± SD: 27h38min ± 3h55min) conducted in hot and dry environmental conditions (30ºC to 40ºC and 31% to 40% relative humidity). Body mass and tympanic temperature were measured, and venous blood samples were taken before (pre-stage) and immediately after (post-stage) each stage of the ultra-marathon for the analysis of gram-negative bacterial endotoxin, C-reactive protein, cytokine profile (IL-6, IL-1β, TNF-α, IFN-γ, IL-10, and IL- 1ra), and plasma osmolality. Gastrointestinal symptoms and perceptive thermal tolerance rating were also monitored throughout competition. Mean exercise-induced body mass loss over the five stages ranged 1.0% to 2.5%. Pre- and poststage plasma osmolality in UER ranged277 to 282mOsmol/kg and 286 to 297 mOsmol/kg, respectively. Pre-stage concentrations of endotoxin (peak: 21% at Stage 5), C-reactive protein (889% at Stage 3), IL-6 (152% at Stage 2), IL-1β (95% at Stage 5), TNF-α (168% at Stage 5), IFN-γ (102% at Stage 5),IL-10 (1271% at Stage 3), and IL-1ra (106% at Stage 5) increased as the ultra-marathon progressed in UER; while no changes in CON were observed (except for IL-1β, 71% at Stage 5). Pre- to post-stage increases were observed for endotoxin (peak: 22% at Stage 3), C-reactive protein (25% at Stage 1), IL-6 (238% at Stage 1), IL-1β (64% at Stage 1), TNF-α (101% at Stage 1), IFN-γ (39% at Stage 1), IL-10 (1100% at Stage 1), and IL-1ra(207% at Stage 1) concentrations in UER. Multi-stage ultra-marathon competition in the heat resulted in a modest circulatory endotoxaemia accompanied by a pronounced pro-inflammatory cytokinaemia by post

  15. Impacts of Individual Animal Response to Heat and Handling Stresses on Escherichia coli and E. coli O157:H7 Fecal Shedding by Feedlot Cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The reduction of foodborne pathogens in cattle destined for human consumption will require knowledge of the factors that impact the carriage and shedding of these organisms. The effects of heat and handling stress levels on the fecal shedding of Escherichia coli O157:H7 and generic E. coli by feedl...

  16. Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways.

    PubMed

    Dues, Dylan J; Andrews, Emily K; Schaar, Claire E; Bergsma, Alexis L; Senchuk, Megan M; Van Raamsdonk, Jeremy M

    2016-04-01

    In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxidative stress response, and the DAF-16-mediated stress response. We find that the decline in stress resistance with age is at least partially due to a decreased ability to activate protective mechanisms in response to stress. In contrast, we find that any baseline increase in stress caused by the advancing age is too mild to detectably upregulate any of the stress response pathways. Further exploration of how worms respond to stress with increasing age revealed that the ability to mount a hormetic response to heat stress is also lost with increasing age. Overall, this work demonstrates that resistance to all types of stress declines with age. Based on our data, we speculate that the decrease in stress resistance with advancing age results from a genetically-programmed inactivation of stress response pathways, not accumulation of damage. PMID:27053445

  17. Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways

    PubMed Central

    Bergsma, Alexis L.; Senchuk, Megan M.; Van Raamsdonk, Jeremy M.

    2016-01-01

    In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxidative stress response, and the DAF-16-mediated stress response. We find that the decline in stress resistance with age is at least partially due to a decreased ability to activate protective mechanisms in response to stress. In contrast, we find that any baseline increase in stress caused by the advancing age is too mild to detectably upregulate any of the stress response pathways. Further exploration of how worms respond to stress with increasing age revealed that the ability to mount a hormetic response to heat stress is also lost with increasing age. Overall, this work demonstrates that resistance to all types of stress declines with age. Based on our data, we speculate that the decrease in stress resistance with advancing age results from a genetically-programmed inactivation of stress response pathways, not accumulation of damage. PMID:27053445

  18. Sphingolipids are potential heat stress signals in Saccharomyces.

    PubMed

    Dickson, R C; Nagiec, E E; Skrzypek, M; Tillman, P; Wells, G B; Lester, R L

    1997-11-28

    The ability of organisms to quickly respond to stresses requires the activation of many intracellular signal transduction pathways. The sphingolipid intermediate ceramide is thought to be particularly important for activating and coordinating signaling pathways during mammalian stress responses. Here we present the first evidence that ceramide and other sphingolipid intermediates are signaling molecules in the Saccharomyces cerevisiae heat stress response. Our data show a 2-3-fold transient increase in the concentration of C18-dihydrosphingosine and C18-phytosphingosine, more than a 100-fold transient increase in C20-dihydrosphingosine and C20-phytosphingosine, and a more stable 2-fold increase in ceramide containing C18-phytosphingosine and a 5-fold increase in ceramide containing C20-phytosphingosine following heat stress. Treatment of cells with dihydrosphingosine activates transcription of the TPS2 gene encoding a subunit of trehalose synthase and causes trehalose, a known thermoprotectant, to accumulate. Dihydrosphingosine induces expression of a STRE-LacZ reporter gene, showing that the global stress response element, STRE, found in many yeast promoter sequences can be activated by sphingolipid signals. The TPS2 promoter contains four STREs that may mediate dihydrosphingosine responsiveness. Using genetic and other approaches it should be possible to identify sphingolipid signaling pathways in S. cerevisiae and quantify the importance of each during heat stress. PMID:9374502

  19. Heat stress causes oxidative stress but not inflammatory signaling in porcine skeletal muscle

    PubMed Central

    Montilla, Sandra I Rosado; Johnson, Theresa P; Pearce, Sarah C; Gardan-Salmon, Delphine; Gabler, Nicholas K; Ross, Jason W; Rhoads, Robert P; Baumgard, Lance H; Lonergan, Steven M; Selsby, Joshua T

    2014-01-01

    Heat stress is associated with death and other maladaptions including muscle dysfunction and impaired growth across species. Despite this common observation, the molecular effects leading to these pathologic changes remain unclear. The purpose of this study was to determine the extent to which heat stress disrupted redox balance and initiated an inflammatory response in oxidative and glycolytic skeletal muscle. Female pigs (5–6/group) were subjected to thermoneutral (20 °C) or heat stress (35 °C) conditions for 1 or 3 days and the semitendinosus removed and dissected into red (STR) and white (STW) portions. After 1 day of heat stress, relative abundance of proteins modified by malondialdehyde, a measure of oxidative damage, was increased 2.5-fold (P < 0.05) compared with thermoneutral in the STR but not the STW, before returning to thermoneutral conditions following 3 days of heat stress. This corresponded with increased catalase and superoxide dismutase-1 gene expression (P < 0.05) and superoxide dismutase-1 protein abundance (P < 0.05) in the STR but not the STW. In the STR catalase and total superoxide dismutase activity were increased by ~30% and ~130%, respectively (P < 0.05), after 1 day of heat stress and returned to thermoneutral levels by day 3. One or 3 days of heat stress did not increase inflammatory signaling through the NF-κB pathway in the STR or STW. These data suggest that oxidative muscle is more susceptible to heat stress-mediated changes in redox balance than glycolytic muscle during chronic heat stress.

  20. Effect of multiple microsporidian infections and temperature stress on the heat shock protein 70 (hsp70) response of the amphipod Gammarus pulex

    PubMed Central

    2014-01-01

    Background Increasing temperatures can be a significant stressor for aquatic organisms. Amphipods are one of the most abundant and functionally important groups of freshwater macroinvertebrates. Therefore, we conducted a laboratory experiment with Gammarus pulex, naturally infected with microsporidians. Methods In each group, 42 gammarids were exposed to 15°C and 25°C for 24 h. Sex of gammarids was determined and microsporidian infections were detected by specific PCR. To quantify stress levels of the amphipods, the 70 kDa heat shock proteins (hsp70) were analyzed by western blot. Results More males than females were detected in the randomized population sample (ratio of females/males: 0.87). No mortality occurred at 15°C, while 42.9% of gammarids died at 25°C. Sequences of three microsporidians (M1, M2, M3) were detected in this G. pulex population (99.7%-100% sequence identity to Microsporidium spp. from GenBank). Previous studies showed that M3 is vertically transmitted, while M1 and M2 are presumably horizontally transmitted. Prevalences, according to PCR, were 27.0%, 37.8% and 64.9% for Microsporidium sp. M1, M2 and M3, respectively. Cumulative prevalence was 82.4%. Multiple infections with all three microsporidians in single gammarids were detected with a prevalence of 8.1%, and bi-infections ranged between 12.2% and 25.7%. In dead gammarids, comparatively low prevalences were noted for M1 (males and females: 11.1%) and M2 (females: 11.1%; males 0%), while prevalence of M3 was higher (females: 66.7%; males: 88.9%). No significant effect of host sex on microsporidian infection was found. Significant effects of temperature and bi-infection with Microsporidium spp. M2 + M3 on hsp70 response were detected by analysis of the whole sample (15°C and 25°C group) and of M2 + M3 bi-infection and gammarid weight when analyzing the 25°C group separately. None of the parameters had a significant effect on hsp70 levels in the 15°C group. Conclusion This

  1. Body Temperature Versus Microclimate Selection in Heat Stressed Dairy Cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this study is to characterize the thermoregulatory responses of unrestrained heat-stressed dairy cows within a freestall environment using fan and spray configurations for cooling cows while lying or standing. An experimental treatment sprayed individual cows lying in freestalls from ...

  2. Differential expression pattern of heat shock protein 70 gene in tissues and heat stress phenotypes in goats during peak heat stress period.

    PubMed

    Rout, P K; Kaushik, R; Ramachandran, N

    2016-07-01

    It has been established that the synthesis of heat shock protein 70 (Hsp70) is temperature-dependent. The Hsp70 response is considered as a cellular thermometer in response to heat stress and other stimuli. The variation in Hsp70 gene expression has been positively correlated with thermotolerance in Drosophila melanogaster, Caenorhabditis elegans, rodents and human. Goats have a wide range of ecological adaptability due to their anatomical and physiological characteristics; however, the productivity of the individual declines during thermal stress. The present study was carried out to analyze the expression of heat shock proteins in different tissues and to contrast heat stress phenotypes in response to chronic heat stress. The investigation has been carried out in Jamunapari, Barbari, Jakhrana and Sirohi goats. These breeds differ in size, coat colour and production performance. The heat stress assessment in goats was carried out at a temperature humidity index (THI) ranging from 85.36-89.80 over the period. Phenotyping for heat stress susceptibility was carried out by combining respiration rate (RR) and heart rate (HR). Based on the distribution of RR and HR over the breeds in the population, individual animals were recognized as heat stress-susceptible (HSS) and heat stress-tolerant (HST). Based on their physiological responses, the selected animals were slaughtered for tissue collection during peak heat stress periods. The tissue samples from different organs such as liver, spleen, heart, testis, brain and lungs were collected and stored at -70 °C for future use. Hsp70 concentrations were analyzed from tissue extract with ELISA. mRNA expression levels were evaluated using the SYBR green method. Kidney, liver and heart had 1.5-2.0-fold higher Hsp70 concentrations as compared to other organs in the tissue extracts. Similarly, the gene expression pattern of Hsp70 in different organs indicated that the liver, spleen, brain and kidney exhibited 5.94, 4.96, 5

  3. An overview of stress response proteomes in Listeria monocytogenes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 prot...

  4. Neuronal responses to physiological stress.

    PubMed

    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

  5. Neuronal Responses to Physiological Stress

    PubMed Central

    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

  6. Evaluation of 3-hydroxybutyrate as an enzyme-protective agent against heating and oxidative damage and its potential role in stress response of poly(3-hydroxybutyrate) accumulating cells.

    PubMed

    Obruca, Stanislav; Sedlacek, Petr; Mravec, Filip; Samek, Ota; Marova, Ivana

    2016-02-01

    Poly(3-hydroxybutyrate) (PHB) is a common carbon- and energy-storage compound simultaneously produced and degraded into its monomer 3-hydroxybutyrate (3HB) by numerous bacteria and Archae in a metabolic pathway called the PHB cycle. We investigated 3HB as a chemical chaperone capable of protecting model enzymes, namely lipase and lysozyme, from adverse effects of high temperature and oxidation. Heat-mediated denaturation of lipase in the presence or absence of 3HB was monitored by dynamic light scattering (DLS) revealing a significant protective effect of 3HB which increased as its concentration rose. Furthermore, when compared at the same molar concentration, 3HB showed a greater protective effect than the well-known chemical chaperones trehalose and hydroxyectoine. The higher protective effect of 3HB was also confirmed when employing differential scanning calorimetry (DSC) and lysozyme as a model enzyme. Furthermore, 3HB was capable of protecting lipase not only against thermal-mediated denaturation but also against oxidative damage by Cu(2+) and H2O2; its protection was higher than that of trehalose and comparable to that of hydroxyectoine. Taking into account that the PHB-producing strain Cupriavidus necator H16 reveals a 16.5-fold higher intracellular concentration than the PHB non-producing mutant C. necator PHB(-4), it might be expected that the functional PHB cycle might be responsible for maintaining a higher intracellular level of 3HB which, aside from other positive aspects of functional PHB metabolism, enhances stress resistance of bacterial strains capable of simultaneous PHB synthesis and mobilization. In addition, 3HB can be used in various applications and formulations as an efficient enzyme-stabilizing and enzyme-protecting additive. PMID:26590589

  7. Reductions in labour capacity from heat stress under climate warming

    NASA Astrophysics Data System (ADS)

    Dunne, John P.; Stouffer, Ronald J.; John, Jasmin G.

    2013-06-01

    A fundamental aspect of greenhouse-gas-induced warming is a global-scale increase in absolute humidity. Under continued warming, this response has been shown to pose increasingly severe limitations on human activity in tropical and mid-latitudes during peak months of heat stress. One heat-stress metric with broad occupational health applications is wet-bulb globe temperature. We combine wet-bulb globe temperatures from global climate historical reanalysis and Earth System Model (ESM2M) projections with industrial and military guidelines for an acclimated individual's occupational capacity to safely perform sustained labour under environmental heat stress (labour capacity)--here defined as a global population-weighted metric temporally fixed at the 2010 distribution. We estimate that environmental heat stress has reduced labour capacity to 90% in peak months over the past few decades. ESM2M projects labour capacity reduction to 80% in peak months by 2050. Under the highest scenario considered (Representative Concentration Pathway 8.5), ESM2M projects labour capacity reduction to less than 40% by 2200 in peak months, with most tropical and mid-latitudes experiencing extreme climatological heat stress. Uncertainties and caveats associated with these projections include climate sensitivity, climate warming patterns, CO2 emissions, future population distributions, and technological and societal change.

  8. Physiological Responses to Thermal Stress and Exercise

    NASA Astrophysics Data System (ADS)

    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.

  9. Arabidopsis HIT4, a regulator involved in heat-triggered reorganization of chromatin and release of transcriptional gene silencing, relocates from chromocenters to the nucleolus in response to heat stress.

    PubMed

    Wang, Lian-Chin; Wu, Jia-Rong; Hsu, Yi-Ju; Wu, Shaw-Jye

    2015-01-01

    Arabidopsis HIT4 is known to mediate heat-induced decondensation of chromocenters and release from transcriptional gene silencing (TGS) with no change in the level of DNA methylation. It is unclear whether HIT4 and MOM1, a well-known DNA methylation-independent transcriptional silencer, have overlapping regulatory functions. A hit4-1/mom1 double mutant strain was generated. Its nuclear morphology and TGS state were compared with those of wild-type, hit4-1, and mom1 plants. Fluorescent protein tagging was employed to track the fates of HIT4, hit4-1 and MOM1 in vivo under heat stress. HIT4- and MOM1-mediated TGS were distinguishable. Both HIT4 and MOM1 were localized normally to chromocenters. Under heat stress, HIT4 relocated to the nucleolus, whereas MOM1 dispersed with the chromocenters. hit4-1 was able to relocate to the nucleolus under heat stress, but its relocation was insufficient to trigger the decompaction of chromocenters. The hypersensitivity to heat associated with the impaired reactivation of TGS in hit4-1 was not alleviated by mom1-induced release from TGS. HIT4 delineates a novel and MOM1-independent TGS regulation pathway. The involvement of a currently unidentified component that links HIT4 relocation and the large-scale reorganization of chromatin, and which is essential for heat tolerance in plants is hypothesized. PMID:25329561

  10. Heat Stress- and Heat Shock Transcription Factor-Dependent Expression and Activity of Ascorbate Peroxidase in Arabidopsis1

    PubMed Central

    Panchuk, Irina I.; Volkov, Roman A.; Schöffl, Friedrich

    2002-01-01

    To find evidence for a connection between heat stress response, oxidative stress, and common stress tolerance, we studied the effects of elevated growth temperatures and heat stress on the activity and expression of ascorbate peroxidase (APX). We compared wild-type Arabidopsis with transgenic plants overexpressing heat shock transcription factor 3 (HSF3), which synthesize heat shock proteins and are improved in basal thermotolerance. Following heat stress, APX activity was positively affected in transgenic plants and correlated with a new thermostable isoform, APXS. This enzyme was present in addition to thermolabile cytosolic APX1, the prevalent isoform in unstressed cells. In HSF3-transgenic plants, APXS activity was detectable at normal temperature and persisted after severe heat stress at 44°C. In nontransgenic plants, APXS was undetectable at normal temperature, but could be induced by moderate heat stress. The mRNA expression profiles of known and three new Apx genes were determined using real-time PCR. Apx1 and Apx2 genes encoding cytosolic APX were heat stress and HSF dependently expressed, but only the representations of Apx2 mRNA met the criteria that suggest identity between APXS and APX2: not expressed at normal temperature in wild type, strong induction by heat stress, and HSF3-dependent expression in transgenic plants. Our data suggest that Apx2 is a novel heat shock gene and that the enzymatic activity of APX2/APXS is required to compensate heat stress-dependent decline of APX1 activity in the cytosol. The functional roles of modulations of APX expression and the interdependence of heat stress and oxidative stress response and signaling mechanisms are discussed. PMID:12068123