scholarly journals Impact of moderate heat stress on the biochemical and physiological responses of the invasive waterweed Elodea canadensis (Michx. 1803)

2018 ◽  
Vol 70 (3) ◽  
pp. 551-557
Author(s):  
Marina Savicka ◽  
Aleksandrs Petjukevics ◽  
Anna Batjuka ◽  
Nataļja Skute
Keyword(s):  
Heat Stress ◽  
Photosynthetic Pigments ◽  
Stress Responses ◽  
Catalase Activity ◽  
Electrolyte Leakage ◽  
Molecular Mechanisms ◽  
Physiological Stress ◽  
Freshwater Ecosystems ◽  
Elodea Canadensis ◽  
Gradual Change

Global warming can negatively affect freshwater macrophytes. However, the degree to which freshwater plants can survive after long-term or short-term warming and the underlying molecular mechanisms are not fully understood. The aim of our study was to analyze the responses of an invasive plant to moderate heat stress (HS). Biochemical and physiological stress responses to experimental warming (30?}1.0?C/25?}1.0?C, day/night) were assessed in the invasive waterweed Elodea canadensis. The effect of the moderate HS on the macrophyte was evaluated through changes in the total protein content, catalase activity, lipid peroxidation, cellular membrane permeability by electrolyte leakage and the concentrations of carotenoids and photosynthetic pigments. Catalase activity and carotenoid concentrations increased significantly (p<0.01) in comparison to the control. A significant increase (p<0.05) in malondialdehyde concentration was observed. However, at the same time there was a persistent low level of electrolyte leakage in heat-treated plants as compared to the control. The results demonstrated that moderate HS improved membrane stability and increased the concentration of photosynthetic pigments and antioxidant activity in E. canadensis shoots. Moderate alterations in temperature may favorably affect the physiology and growth of the invasive macrophyte E. canadensis. It is reasonable to expect that warming could lead to a gradual change in E. canadensis distribution and to changes in composition of freshwater ecosystems.

scholarly journals Elongation of stigmatic papillae induced by heat stress is associated with disturbance of pollen attachment in Arabidopsis thaliana

2019 ◽  
Author(s):  
Kazuma Katano ◽  
Takao Oi ◽  
Nobuhiro Suzuki
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Morphological Changes ◽  
Reproductive Organs ◽  
Histochemical Staining ◽  
Morphological Alteration ◽  
Yield Production ◽  
Stigmatic Papillae

ABSTRUCTHeat stress can seriously impact on yield production and quality of crops. Many studies uncovered the molecular mechanisms that regulate heat stress responses in plants. Nevertheless, effects of heat stress on the morphology of plants were still not extensively studied. In this study, we observed the detailed morphological changes of reproductive organs in Arabidopsis thaliana caused by heat stress. Larger area of stigma, and shorter length of anthers, filaments and petals were observed in plants subjected to heat stress compared to those under controlled conditions. Scanning electron microscopy (SEM) observation showed that length of stigmatic papillae without pollens seemed to be longer than that with pollens. In addition, classification of stigmas based on pollen attachment patterns together with artificial pollination assay revealed that pollen attachment onto stigma was clearly decreased by heat stress, and indicated that heat induced elongation of stigmatic papillae might be associated with disturbance of pollen attachment onto stigma. Furthermore, histochemical staining experiments revealed that crosstalk between Ca2+ and NO derived from pollens and O2− derived from stigma might be associated with morphological alteration of stigma.

scholarly journals Transcriptomic Analysis Provides Novel Insights into Heat Stress Responses in Sheep

Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 387 ◽  
Author(s):  
Zengkui Lu ◽  
Mingxing Chu ◽  
Qing Li ◽  
Meilin Jin ◽  
Xiaojuan Fei ◽  
...  
Keyword(s):  
Heat Stress ◽  
Differentially Expressed Genes ◽  
Stress Responses ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Transcriptomic Analysis ◽  
Differentially Expressed ◽  
P Value ◽  
Comprehensive Overview

With the intensified and large-scale development of sheep husbandry and global warming, sheep heat stress has become an increasingly important issue. However, little is known about the molecular mechanisms related to sheep responses to heat stress. In this study, transcriptomic analysis of liver tissues of sheep in the presence and absence of heat stress was conducted, with the goal of identifying genes and pathways related to regulation when under such stress. After a comparison with the sheep reference genome, 440,226,436 clean reads were obtained from eight libraries. A p-value ≤ 0.05 and fold change ≥ 2 were taken as thresholds for categorizing differentially expressed genes, of which 1137 were identified. The accuracy and reliability of the RNA-Seq results were confirmed by qRT-PCR. The identified differentially expressed genes were significantly associated with 419 GO terms and 51 KEGG pathways, which suggested their participation in biological processes such as response to stress, immunoreaction, and fat metabolism. This study’s results provide a comprehensive overview of sheep heat stress-induced transcriptional expression patterns, laying a foundation for further analysis of the molecular mechanisms of sheep heat stress.

scholarly journals Chronic prenatal heat stress alters growth, carcass composition, and physiological response of growing pigs subjected to postnatal heat stress

2020 ◽  
Vol 98 (5) ◽  
Author(s):  
Aira Maye Serviento ◽  
Bénédicte Lebret ◽  
David Renaudeau
Keyword(s):  
Heat Stress ◽  
Stress Responses ◽  
Physiological Stress ◽  
Female Offspring ◽  
Growing Pigs ◽  
Carcass Composition ◽  
Dependent Manner ◽  
Nonesterified Fatty Acids ◽  
Altered Thyroid ◽  
Skin Temperatures

Abstract Postnatal heat stress (HS) effects on pig physiology and performance are widely studied but prenatal HS studies, albeit increasing, are still limited. The objective of this study was to evaluate the chronic prenatal HS effects in growing pigs raised in postnatal thermoneutral (TN) or in HS environment. For prenatal environment (PE), mixed-parity pregnant sows were exposed to either TN (PTN; cyclic 18 to 24 °C; n = 12) or HS (PHS; cyclic 28 to 34 °C; n = 12) conditions from day 9 to 109 of gestation. Two female offspring per sow were selected at 10 wk of age and allotted to one of two postnatal growing environments (GE): GTN (cyclic 18 to 24 °C; n = 24) and GHS (cyclic 28 to 34 °C; n = 24). From 75 to 140 d of age, GTN pigs remained in GTN conditions, while GHS pigs were in GTN conditions from 75 to 81 d of age and in GHS conditions from 82 to 140 d of age. Regardless of PE, postnatal HS increased rectal and skin temperatures (+0.30 and +1.61 °C on average, respectively; P &lt; 0.01) and decreased ADFI (−332 g/d; P &lt; 0.01), resulting in lower ADG and final BW (−127 g/d and −7.9 kg, respectively; P &lt; 0.01). The GHS pigs exhibited thicker backfat (P &lt; 0.01), lower carcass loin percentage (P &lt; 0.01), increased plasma creatinine levels (P &lt; 0.01), and decreased plasma glucose, nonesterified fatty acids, T3, and T4 levels (P &lt; 0.05). Prenatal HS increased feed intake in an age-dependent manner (+10 g·kg BW–0.60·d−1 for PHS pigs in the last 2 wk of the trial; P = 0.02) but did not influence BW gain (P &gt; 0.10). Prenatal HS decreased the plasma levels of superoxide dismutase on day 3 of GHS (trend at P = 0.08) and of T4 on day 49 (P &lt; 0.01) but did not affect T3 on day 3 nor 49 (P &gt; 0.10). Prenatal HS increased rectal and skin temperatures and decreased temperature gradient between rectal and skin temperatures in GTN pigs (+0.10, +0.33 and −0.22 °C, respectively; P &lt; 0.05) but not in GHS pigs (P &gt; 0.10). There were also PE × GE interactions found with lower BW (P = 0.06) and higher backfat (P &lt; 0.01) and perirenal adiposity (P &lt; 0.05) for GHS–PHS pigs than the other groups. Overall, increased body temperature and altered thyroid functions and physiological stress responses suggest decreased heat tolerance and dissipation ability of pigs submitted to a whole-gestation chronic prenatal HS. Postnatal HS decreased growth performance, increased carcass adiposity, and affected metabolic traits and thyroid functions especially in pigs previously submitted to prenatal HS.

scholarly journals Characterization of Heat Responsive microRNAs and Phased Small Interfering RNAs in Reproductive Development of Flax

2021 ◽  
Author(s):  
Suresh Pokhrel ◽  
Blake C. Meyers
Keyword(s):  
Heat Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Reproductive Development ◽  
Differentially Expressed ◽  
Small Interfering Rnas ◽  
Coding Regions ◽  
Reproductive Tissues ◽  
Mirna Genes ◽  
Plant Reproductive Development

Plants will face increased heat stress due to rising global temperatures. Heat stress affects plant reproductive development and decreases productivity; however, the underlying molecular mechanisms of these processes are poorly characterized. Plant small RNAs (sRNAs) have important regulatory roles in plant reproductive development following abiotic stress responses. We generated sRNA transcriptomes of three reproductive bud stages at three different time points to identify sRNA-mediated pathways responsive to heat stress in flax. With added sRNA transcriptomes of vegetative tissues, we comprehensively annotated miRNA and phasiRNA-encoding genes (PHAS) in flax. We identified 173 miRNA genes, of which 42 are novel. Our analysis revealed that 141 miRNA genes were differentially expressed between tissue types while 18 miRNA genes were differentially expressed in reproductive tissues following heat stress, including members of miR2118/482 and miR2275 families, known triggers of reproductive phasiRNAs. Furthermore, we identified 68 21-PHAS flax loci from protein coding and non-coding regions, four 24-PHAS loci triggered by miR2275, and 658 24-PHAS-like loci with unknown triggers, derived mostly from non-coding regions. The reproductive phasiRNAs are mostly downregulated in response to heat stress. Overall, we found that several previously unreported miRNAs and phasiRNAs are responsive to heat stress in flax reproductive tissues.

scholarly journals Divergent epigenetic profiles from two differentially impacted wild populations of estuarine cordgrass (Sporobolus alterniflorus)

2021 ◽  
Author(s):  
L. DeCarlo ◽  
F. Meckler ◽  
M. Hans ◽  
S. Kelemen ◽  
H. Magun ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Heat Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Epigenetic Modification ◽  
River Estuary ◽  
Global Dna Methylation ◽  
List Type ◽  
Acute Heat Stress ◽  
Bronx River

AbstractThe effects of urbanization on watershed ecosystems present critical challenges to modern survival. Organisms in urbanized areas experience high rates of evolutionary change, but genetic adaptation alone cannot mitigate the rapid and severe effects of urbanization on biodiversity. Highly resilient, foundation species are key to maintaining an ecosystem’s integrity in the face of urban stressors. However, the rapid collapse and disappearance of watershed ecosystems calls into question the extent to which we can rely on such species for their services. Our research investigates the molecular mechanisms by which the foundation ecosystems provider, Sporobolus alterniflorus, adapts to life in an urbanized environment. To elucidate these mechanisms, we quantified changes in global DNA methylation (% 5-mC) as a result of acute heat stress. Specimens from two differentially impacted populations across an urban to suburban geographical transect formed the basis of this study. These two populations of Sporobolus alterniflora exhibit inverse global DNA methylation patterns when exposed to the same acute heat stress. Our findings suggest that epigenetic mechanisms, such as DNA methylation, control rapid and transient adaptation, in the form of differential stress responses, to distinct environment challenges.Highlights for manuscript submission▪estuarine grasses native to the Bronx River, NY face stresses associated with low dissolved oxygen and urbanization▪differentially impacted populations of estuarine grasses exhibit inverse global DNA methylation profiles in response to acute heat stress▪DNA methylation may represent a mechanism by which plants transiently respond to environmental stressors, and this may represent a form of rapid adaptive evolution▪stress priming by transgenerational epigenetic modification may enhance fitness in grasses native to the heavily impacted Bronx River estuary

Emotions and health: The impact of emotions, emotions regulation, music, and acculturation on health

2008 ◽  
Vol 16 (3) ◽  
pp. 112-115 ◽  
Author(s):  
Stephan Bongard ◽  
Volker Hodapp ◽  
Sonja Rohrmann
Keyword(s):  
Stress Responses ◽  
Physiological Stress ◽  
Anger Expression ◽  
Domain Specific ◽  
Cardiovascular Stress ◽  
Expression Behavior ◽  
Cardio Vascular ◽  
And Coping ◽  
Relationship Of ◽  
The Impact

Abstract. Our unit investigates the relationship of emotional processes (experience, expression, and coping), their physiological correlates and possible health outcomes. We study domain specific anger expression behavior and associated cardio-vascular loads and found e.g. that particularly an open anger expression at work is associated with greater blood pressure. Furthermore, we demonstrated that women may be predisposed for the development of certain mental disorders because of their higher disgust sensitivity. We also pointed out that the suppression of negative emotions leads to increased physiological stress responses which results in a higher risk for cardiovascular diseases. We could show that relaxation as well as music activity like singing in a choir causes increases in the local immune parameter immunoglobuline A. Finally, we are investigating connections between migrants’ strategy of acculturation and health and found e.g. elevated cardiovascular stress responses in migrants when they where highly adapted to the German culture.

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