scholarly journals The Effect of Low Temperature on Physiological, Biochemical and Flowering Functions of Olive Tree in Relation to Genotype

2020 ◽  
Vol 12 (23) ◽  
pp. 10065
Author(s):  
Niki Mougiou ◽  
Boushra Baalbaki ◽  
Georgios Doupis ◽  
Nektarios Kavroulakis ◽  
Stylianos Poulios ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Olive Tree ◽  
Mrna Levels ◽  
Adaptive Responses ◽  
Cold Night ◽  
Cultivar Selection ◽  
Abiotic Stress Condition ◽  
Olive Varieties ◽  
Stress Experiment

Olive tree growth and reproduction are severely affected by temperature extremes, compromising fruit yield. In that aspect, the olive varieties “Koroneiki” and “Mastoidis” were employed in a mild cold stress experiment, imitating night frost incidents to assess their biochemical, physiological and reproductive functions in relation to genotype. The physiological performance of the stressed plants was not significantly altered, suggesting that both cultivars were well adapted to mild cold night stress. The biochemical response of the plants, regarding antioxidant enzymes, H2O2 and TBARS accumulation, confirmed that both cultivars could cope with the stress applied. The mRNA levels of the PPO gene, which participates in hydroxytyrosol biosynthesis and plant defense, were elevated after 24-h stress at 0 °C, in both cultivars with “Mastoidis” plants exhibiting higher levels for a longer period. Three more genes involved in hydroxytyrosol biosynthesis upregulated their expression levels as a response to cold stress. The numerous plant phenology aspects measured reinforced the conclusion that both cultivars responded to the stress applied. The results of the present study may contribute to better understanding olive tree adaptive responses to low temperature events, an abiotic stress condition that is often present in an open plantation, thus assisting farmers on breeding and cultivar selection.

scholarly journals RNA-seq analysis provides insights into cold stress responses of Xanthomonas citri pv. citri

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jin-Xing Liao ◽  
Kai-Huai Li ◽  
Jin-Pei Wang ◽  
Jia-Ru Deng ◽  
Qiong-Guang Liu ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Low Temperature ◽  
Cold Stress ◽  
Stress Responses ◽  
Citrus Canker ◽  
Transcriptional Analysis ◽  
Adaptive Responses ◽  
Xanthomonas Citri ◽  
Type Iv ◽  
Expression Of Genes

Abstract Background Xanthomonas citri pv. citri (Xcc) is a citrus canker causing Gram-negative bacteria. Currently, little is known about the biological and molecular responses of Xcc to low temperatures. Results Results depicted that low temperature significantly reduced growth and increased biofilm formation and unsaturated fatty acid (UFA) ratio in Xcc. At low temperature Xcc formed branching structured motility. Global transcriptome analysis revealed that low temperature modulates multiple signaling networks and essential cellular processes such as carbon, nitrogen and fatty acid metabolism in Xcc. Differential expression of genes associated with type IV pilus system and pathogenesis are important cellular adaptive responses of Xcc to cold stress. Conclusions Study provides clear insights into biological characteristics and genome-wide transcriptional analysis based molecular mechanism of Xcc in response to low temperature.

scholarly journals Identification of cold stress responsive microRNAs in cold tolerant and susceptible Hemerocallis fulva by high throughput sequencing

2020 ◽  
Author(s):  
Changbing Huang ◽  
Chun Jiang ◽  
limin Jin ◽  
Huanchao Zhang
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Cold Tolerance ◽  
Temperature Stress ◽  
Stress Responses ◽  
Target Genes ◽  
Low Temperature Stress ◽  
Differentially Expressed ◽  
Differentially Expressed Mirnas ◽  
Cold Tolerant

Abstract Background:Hemerocallis fulva is a perennial herb belonging to Hemerocallis of Hemerocallis. Because of the large and bright colors, it is often used as a garden ornamental plant. But most varieties of H. fulva on the market will wither in winter, which will affect their beauty. It is very important to study the effect of low temperature stress on the physiological indexes of H. fulva and understand the cold tolerance of different H. fulva. MiRNA is a kind of endogenous non coding small molecular RNA with length of 21-24nt. It mainly inhibits protein translation by cutting target genes, and plays an important role in the development of organisms, gene expression and biological stress. Low temperature is the main abiotic stress affecting the production of H. fulva in China, which hinders the growth and development of plants. A comprehensive understanding of the expression pattern of microRNA in H. fulva under low temperature stress can improve our understanding of microRNA mediated stress response. Although there are many studies on miRNAs of various plants under cold stress at home and abroad, there are few studies on miRNAs related to cold stress of H. fulva. It is of great significance to explore the cold stress resistant gene resources of H. fulva, especially the identification and functional research of miRNA closely related to cold stress, for the breeding of excellent H. fulva.Results A total of 5619 cold-responsive miRNAs, 315 putative novel and 5 304 conserved miRNAs, were identified from the leaves and roots of two different varieties ‘Jinyan’ (cold-tolerant) and ‘Lucretius ’ (cold-sensitive), which were stressed under -4 oC for 24 h. Twelve conserved and three novel miRNAs (novel-miR10, novel-miR19 and novel-miR48) were differentially expressed in leaves of ‘Jinyan’ under cold stress. Novel-miR19, novel-miR29 and novel-miR30 were up-regulated in roots of ‘Jinyan’ under cold stress. Thirteen and two conserved miRNAs were deferentially expressed in leaves and roots of ‘Lucretius’ after cold stress. The deferentially expressed miRNAs between two cultivars under cold stress include novel miRNAs and the members of the miR156, miR166 and miR319 families. A total of 6 598 target genes for 6 516 known miRNAs and 82 novel miRNAs were predicted by bioinformatic analysis, mainly involved in metabolic processes and stress responses. Ten differentially expressed miRNAs and predicted target genes were confirmed by quantitative reverse transcription PCR(q-PCR), and the expressional changes of target genes were negatively correlated to differentially expressed miRNAs. Our data indicated that some candidate miRNAs (e.g., miR156a-3-p, miR319a, and novel-miR19) may play important roles in plant response to cold stress.Conclusions Our study indicates that some putative target genes and miRNA mediated metabolic processes and stress responses are significant to cold tolerance in H. fulva.

scholarly journals Different Responses of Cytoplasmic and Endoplasmic Reticulum Hsp90 Genes from Eogystia hippophaecola (Lepidoptera: Cossidae) to Cold Stress

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1039
Author(s):  
Qianqian Wang ◽  
Jing Tao ◽  
Yurong Li ◽  
Yabei Xu ◽  
Xinhai Liu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Low Temperature ◽  
Cold Stress ◽  
Cold Tolerance ◽  
Response Times ◽  
Expression Patterns ◽  
Amino Acid Sequences ◽  
Sea Buckthorn ◽  
Open Reading Frames

Eogystia hippophaecola Hua, Chou, Fang et Chen (Lepidoptera: Cossidae) is an important borer pest of the sea buckthorn forest (Hippophae rhamnoides L.) in China. Its larvae, which are highly cold tolerant, mainly overwinter in sea buckthorn roots. Heat shock proteins (Hsps) are important molecular chaperones that have been linked to cold tolerance in insects. In this study, we cloned the open reading frames (ORFs) of two Hsp90 genes from E. hippophaecola, EhHsp90-1 and EhHsp90-2, and analyzed their expression under cold stress by qRT-PCR. EhHsp90-1 and EhHsp90-2 are 2154 and 2346 bp in length, respectively, encoding 717 and 781 amino acids. The deduced amino acid sequences contain the conserved signature sequences of the Hsp90 family and the C-terminus characteristic sequence of cytoplasmic or endoplasmic reticulum Hsp90 protein. Phylogenetic analysis revealed the amino acid sequences of EhHsp90-1 and EhHsp90-2 were very similar to the corresponding proteins from Lepidoptera. Under various low-temperature treatments lasting 2 h, EhHsp90-1 and EhHsp90-2 exhibited similar expression patterns, increasing first and then decreasing. At −5 °C, EhHsp90-1 was significantly up-regulated after 12 h, whereas EhHsp90-2 was up-regulated after just 1 h and reached its highest level at 2 h; however, the overall degree of upregulation was greater for EhHsp90-1. Subsequently, the expression level of EhHsp90-2 fluctuated with time. Our results suggest that the two Hsp90s play important roles in E. hippophaecola larvae response to cold stress, but that their response times and the magnitudes of their responses to low-temperature stress differed significantly, providing a theoretical basis for further studying the molecular mechanism of cold tolerance in E. hippophaecola larvae.

scholarly journals Homeostatic state of microglia in a rat model of chronic sleep restriction

SLEEP ◽  
2020 ◽  
Vol 43 (11) ◽  
Author(s):  
Shannon Hall ◽  
Samüel Deurveilher ◽  
George S Robertson ◽  
Kazue Semba
Keyword(s):  
Rat Model ◽  
Inflammatory Cytokine ◽  
Male Rats ◽  
Sleep Restriction ◽  
Mrna Levels ◽  
Prelimbic Cortex ◽  
Adaptive Responses ◽  
Brain Functions ◽  
Anti Inflammatory ◽  
Chronic Sleep

Abstract Chronic sleep restriction (CSR) negatively impacts brain functions. Whether microglia, the brain’s resident immune cells, play any role is unknown. We studied microglia responses to CSR using a rat model featuring slowly rotating wheels (3 h on/1 h off), which was previously shown to induce both homeostatic and adaptive responses in sleep and attention. Adult male rats were sleep restricted for 27 or 99 h. Control rats were housed in locked wheels. After 27 and/or 99 h of CSR, the number of cells immunoreactive for the microglia marker ionized calcium-binding adaptor molecule-1 (Iba1) and the density of Iba1 immunoreactivity were increased in 4/10 brain regions involved in sleep/wake regulation and cognition, including the prelimbic cortex, central amygdala, perifornical lateral hypothalamic area, and dorsal raphe nucleus. CSR neither induced mitosis in microglia (assessed with bromodeoxyuridine) nor impaired blood–brain barrier permeability (assessed with Evans Blue). Microglia appeared ramified in all treatment groups and, when examined quantitatively in the prelimbic cortex, their morphology was not affected by CSR. After 27 h, but not 99 h, of CSR, mRNA levels of the anti-inflammatory cytokine interleukin-10 were increased in the frontal cortex. Pro-inflammatory cytokine mRNA levels (tumor necrosis factor-α, interleukin-1β, and interleukin-6) were unchanged. Furthermore, cortical microglia were not immunoreactive for several pro- and anti-inflammatory markers tested, but were immunoreactive for the purinergic P2Y12 receptor. These results suggest that microglia respond to CSR while remaining in a physiological state and may contribute to the previously reported homeostatic and adaptive responses to CSR.

scholarly journals Chromatin-Level Differences Elucidate Potential Determinants of Contrasting Levels of Cold Sensitivity in Maize Lines

2020 ◽  
Author(s):  
Maciej Jończyk ◽  
Alicja Sobkowiak ◽  
Joanna Trzcinska-Danielewicz ◽  
Paweł Sowiński
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Photosynthetic Apparatus ◽  
Regulatory Elements ◽  
Cold Sensitivity ◽  
Regulatory Sequences ◽  
Physiological Level ◽  
Cold Tolerant ◽  
Tolerant Line ◽  
Cold Sensitive

Abstract Maize is a subtropical, cold-sensitive species. However, some varieties of this species have the potential to withstand long-term low temperatures, even at the seedling stage. The molecular basis of this phenomenon has not been determined. In a chromatin-level study, we compared the cold-stress reaction of seedlings of two maize inbred lines showing contrasting levels of cold sensitivity. The cold-tolerant line was selected based on field data and previous physiological and transcriptomic level studies. The first condition of gene expression—chromatin accessibility—was assessed by formaldehyde-aided isolation of regulatory elements method and DNA sequencing. Potentially expressed genes and cis-regulatory sequences open for interaction with transcription factors have been defined. The results of this study suggest that during cold stress, the tolerant maize line shifted resources from growth to defense. This shift was shown by potential hormone-level events—degradation of growth-promoting gibberellins and synthesis of jasmonic and abscisic acids. This finding is congruent with the xeromorphic morphology of seedlings of the cold-tolerant line and their ability to regrow when stress ceases. It is a common reaction of cold-tolerant maize lines. Moreover, in the cold-tolerant line, several genes from the low-temperature signaling pathways were potentially expressed. Additionally, numerous stress-response AP2/EREBP-binding cis-motifs were accessible in the cold-tolerant line. Differently in the cold-sensitive B73 line, MADS-binding cis-motifs were the most abundant. Development of the photosynthetic apparatus is crucial for the survival of maize seedlings at low temperature. Our results suggest efficient photosynthesis in seedlings of the cold-tolerant line, as was described earlier in physiological-level analyses.

scholarly journals Effects of TiO2 nanoparticles and spermine on antioxidant responses of Glycyrrhiza glabra L. to cold stress

2020 ◽  
Vol 79 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Vahideh Kardavan Ghabel ◽  
Roya Karamian
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Tio2 Nanoparticles ◽  
Growth Parameters ◽  
Stress Conditions ◽  
Glycyrrhiza Glabra ◽  
Tio2 Nps ◽  
Randomized Design ◽  
Glycyrrhiza Glabra L ◽  
Physiological And Biochemical

Licorice (Glycyrrhiza glabra L.) is known as an important medicinal plant throughout the world. Glycyrrhizin is one of the most important specialized metabolites produced by licorice. In order to study the effect of TiO2 nanoparticles (TiO2 NPs) and spermine on physiological and biochemical traits of licorice under cold stress conditions, a factorial experiment was conducted in a completely randomized design with three replications. Plants were exposed to optimum temperature (26 ºC) as control and low temperature (4 ºC) as cold stress conditions and also treated with TiO2 NPs (2 and 5 ppm) and spermine (1 mM), separately. Results from physiological and biochemical analyses of the aerial parts of licorice seedlings showed that the growth parameters and the content of photosynthetic pigments decreased in response to low temperature. TiO2 NPs and spermine treatments increased plant resistance to cold stress and decreased the level of oxidative damage by reduction of malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents. In other hand, TiO2 NPs and spermine caused increase of phenolics, total protein and osmolytes contents under cold stress conditions. An increase in glycyrrhizin content was significantly induced by low temperature, TiO2 NPs and spermine.

Pancreatic triacylglycerol lipase in a hibernating mammal. II. Cold-adapted function and differential expression

2003 ◽  
Vol 16 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Teresa L. Squire ◽  
Mark E. Lowe ◽  
Vernon W. Bauer ◽  
Matthew T. Andrews
Keyword(s):  
Low Temperature ◽  
High Activity ◽  
Ground Squirrel ◽  
Mammalian Cells ◽  
Lipolytic Activity ◽  
Tissue Expression ◽  
Ground Squirrels ◽  
Mrna Levels ◽  
Western Blots ◽  
Triacylglycerol Lipase

Thirteen-lined ground squirrels ( Spermophilus tridecemlineatus) exploit the low-temperature activity of pancreatic triacylglycerol lipase (PTL) during hibernation. Lipolytic activity at body temperatures associated with hibernation was examined using recombinant ground squirrel and human PTLs expressed in yeast. Both the human and ground squirrel enzymes displayed high activity at temperatures as low as 0°C and showed Q10 values of 1.2–1.5 over a range of 37–7°C. These studies indicate that low-temperature lipolysis is a general property of PTL and does not require protein modifications unique to mammalian cells and/or the hibernating state. Western blots show elevated levels of PTL protein during hibernation in both heart and white adipose tissue (WAT). Significant increases in PTL gene expression are seen in heart, WAT, and testes; but not in pancreas, where PTL mRNA levels are highest. Upregulation of PTL in testes is also accompanied by expression of the PTL-specific cofactor, colipase. The multi-tissue expression of PTL during hibernation supports its role as a key enzyme that shows high activity at low temperatures.

Association of qLTG3-1 with germination stage cold tolerance in diverse rice germplasm from the Indian subcontinent

2013 ◽  
Vol 11 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Clarissa Challam ◽  
Gayle Alisha Kharshing ◽  
Julia S. Yumnam ◽  
Mayank Rai ◽  
Wricha Tyagi
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Cold Tolerance ◽  
Indian Subcontinent ◽  
Crop Productivity ◽  
Climatic Conditions ◽  
Superior Performance ◽  
Rice Germplasm ◽  
Potential Marker ◽  
Rice Genotypes

Low temperature is a major constraint for crop productivity. To cope with this challenge, plants have developed several mechanisms to adapt to low temperature. Developing breeding strategies to enhance cold stress tolerance in crops requires an understanding of the mechanisms by which plants perceive and transmit cold stress-related signals to their cellular machinery, thereby activating adaptive responses. Only one quantitative trait locus for tolerance to low-temperature germination, qLTG3-1, has been narrowed down to the gene level in rice. A 71 bp indel that can be used to distinguish between tolerant and susceptible parents has been identified. We tested the 71 bp indel on 65 diverse rice genotypes including those adapted to colder climates of North and Northeastern India to find evidence of the tolerant allele (insertion) and to see whether it is associated with low-temperature germinability in these genotypes. Our results show that 48% of the rice genotypes tested carried the tolerant allele. The insertion was found to be significantly associated with cold tolerance during germination. Moreover, several landraces/improved varieties known for their superior performance in other abiotic stress conditions such as drought and high salinity conditions, and which were previously never exposed to low temperature, carry the beneficial allele for qLTG3-1, suggesting an additional role of this allele in adverse climatic conditions. This study enhances current understanding of the distribution of the tolerant allele qLTG3-1 in rice germplasm, which could help in the identification of suitable donors for potential marker-assisted breeding programmes.

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