scholarly journals Evidence for pre-climacteric activation of AOX transcription during cold-induced conditioning to ripen in European pear (Pyrus communis L.)

2019 ◽  
Author(s):  
Christopher Hendrickson ◽  
Seanna Hewitt ◽  
Mark E. Swanson ◽  
Todd Einhorn ◽  
Amit Dhingra
Keyword(s):  
Time Course ◽  
Transcript Abundance ◽  
Ethylene Biosynthesis ◽  
Pyrus Communis ◽  
Cold Temperature ◽  
Fruit Peel ◽  
Physiological Indicators ◽  
Conditioning Model ◽  
Time Course Experiment ◽  
Temperature Exposure

AbstractEuropean pears (Pyrus communis L.) require a range of cold-temperature exposure to induce ethylene biosynthesis and fruit ripening. Physiological and hormonal responses to cold temperature storage in pear have been well characterized, but the molecular underpinnings of these phenomena remain unclear. An established low-temperature conditioning model was used to induce ripening of ‘D’Anjou’ and ‘Bartlett’ pear cultivars and quantify the expression of key genes representing ripening-related metabolic pathways in comparison to non-conditioned fruit. Physiological indicators of pear ripening were recorded, and fruit peel tissue sampled in parallel, during the cold-conditioning and ripening time-course experiment to correlate gene expression to ontogeny. Two complementary approaches, Nonparametric Multi-Dimensional Scaling and efficiency-corrected 2-(ΔΔCt), were used to identify genes exhibiting the most variability in expression. Interestingly, the enhanced alternative oxidase (AOX) transcript abundance at the pre-climacteric stage in ‘Bartlett’ and ‘D’Anjou’ at the peak of the conditioning treatments suggests that AOX may play a key and a novel role in the achievement of ripening competency. There were indications that cold-sensing and signaling elements from ABA and auxin pathways modulate the S1-S2 ethylene transition in European pears, and that the S1-S2 ethylene biosynthesis transition is more pronounced in ‘Bartlett’ as compared to ‘D’Anjou’ pear. This information has implications in preventing post-harvest losses of this important crop.

scholarly journals Evidence for the Involvement of Vernalization-related Genes in the Regulation of Cold-induced Ripening in ‘D’Anjou’ and ‘Bartlett’ Pear Fruit

2019 ◽  
Author(s):  
Seanna Hewitt ◽  
Christopher A. Hendrickson ◽  
Amit Dhingra
Keyword(s):  
Time Course ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Global Gene Expression ◽  
Ethylene Biosynthesis ◽  
Cold Temperature ◽  
European Pear ◽  
System 2 ◽  
Autocatalytic System ◽  
Temperature Exposure

AbstractEuropean pear (Pyrus communis L.) cultivars require a genetically pre-determined duration of cold-temperature exposure to induce autocatalytic system 2 ethylene biosynthesis and subsequent fruit ripening. The physiological responses of pear to cold-temperature-induced ripening have been well characterized, but the molecular mechanisms underlying this phenomenon continue to be elucidated. This study employed established cold temperature conditioning treatments for ripening of two pear cultivars, ‘D’Anjou’ and ‘Bartlett’. Using a time-course transcriptomics approach, global gene expression responses of each cultivar were assessed at four different developmental stages during the cold conditioning process. Differential expression, functional annotation, and gene ontology enrichment analyses were performed. Interestingly, evidence for the involvement of cold-induced, vernalization-related genes and repressors of endodormancy release was found. These genes have not previously been described to play a role in fruit during the ripening transition. The resulting data provide insight into cultivar-specific mechanisms of cold-induced transcriptional regulation of ripening in European pear, as well as a unique comparative analysis of the two cultivars with very different cold conditioning requirements.

scholarly journals Traditional varieties and wild pear from Serbia: A link among antioxidant, antidiabetic and cytotoxic activities of fruit peel and flesh

2021 ◽  
Vol 45 (2) ◽  
pp. 203-213
Author(s):  
Mariana Oaldje-Pavlovic ◽  
Ana Alimpic-Aradski ◽  
Aleksandra Savic ◽  
Smiljana Jankovic ◽  
Milena Milutinovic ◽  
...  
Keyword(s):  
Pyrus Communis ◽  
Cytotoxic Activities ◽  
Commercial Variety ◽  
Pear Fruit ◽  
Cytotoxic Potential ◽  
Fruit Peel ◽  
Methanolic Extracts ◽  
Pathological Conditions ◽  
Prevention And Treatment ◽  
Fruit Part

This study was aimed at evaluating the antioxidant and antidiabetic activities of methanolic extracts of peel, flesh and mixed peel, and flesh, as well as the cytotoxic activity of mixed peel and flesh extracts obtained from fruits of six traditional pear varieties (Vidovaca, Lubenicarka, Karamanka, Jeribasma, Loncara and Takisa), one commercial variety (Williams Bartlett) and a wild pear (Pyrus communis) from Serbia. The tested extracts showed strong antioxidant activity regarding the prevention of ?-carotene bleaching and high ?-glucosidase inhibition, and no significant cytotoxic potential, with the exception of the Williams Bartlett and Pyrus communis extracts. Overall, the most potent fruit part was shown to be the peel. The most active variety in all of the applied antioxidant and antidiabetic assays was Takisa, while the wild pear, P. communis, was the most effective in inhibiting the proliferation of cancer cells. In conclusion, several methanolic extracts of pear fruit are promising candidates for further studies regarding the prevention and treatment of pathological conditions associated with the effects of oxidative stress, such as diabetes and even colorectal cancer.

scholarly journals Using naturalistic incubation temperatures to demonstrate how variation in the timing and continuity of heat wave exposure influences phenotype

2020 ◽  
Vol 287 (1932) ◽  
pp. 20200992 ◽  
Author(s):  
Anthony T. Breitenbach ◽  
Amanda W. Carter ◽  
Ryan T. Paitz ◽  
Rachel M. Bowden
Keyword(s):  
Heat Wave ◽  
Time Course ◽  
Heat Waves ◽  
Heat Exposure ◽  
Effect Of Temperature ◽  
Similar Time ◽  
Expression Of Genes ◽  
Short Period ◽  
The Face ◽  
Temperature Exposure

Most organisms are exposed to bouts of warm temperatures during development, yet we know little about how variation in the timing and continuity of heat exposure influences biological processes. If heat waves increase in frequency and duration as predicted, it is necessary to understand how these bouts could affect thermally sensitive species, including reptiles with temperature-dependent sex determination (TSD). In a multi-year study using fluctuating temperatures, we exposed Trachemys scripta embryos to cooler, male-producing temperatures interspersed with warmer, female-producing temperatures (heat waves) that varied in either timing during development or continuity and then analysed resulting sex ratios. We also quantified the expression of genes involved in testis differentiation ( Dmrt1 ) and ovary differentiation ( Cyp19A1 ) to determine how heat wave continuity affects the expression of genes involved in sexual differentiation. Heat waves applied during the middle of development produced significantly more females compared to heat waves that occurred just 7 days before or after this window, and even short gaps in the continuity of a heat wave decreased the production of females. Continuous heat exposure resulted in increased Cyp19A1 expression while discontinuous heat exposure failed to increase expression in either gene over a similar time course. We report that even small differences in the timing and continuity of heat waves can result in drastically different phenotypic outcomes. This strong effect of temperature occurred despite the fact that embryos were exposed to the same number of warm days during a short period of time, which highlights the need to study temperature effects under more ecologically relevant conditions where temperatures may be elevated for only a few days at a time. In the face of a changing climate, the finding that subtle shifts in temperature exposure result in substantial effects on embryonic development becomes even more critical.

scholarly journals Exposure to Atmospheric Ultrafine Particles Induces Severe Lung Inflammatory Response and Tissue Remodeling in Mice

2019 ◽  
Vol 16 (7) ◽  
pp. 1210 ◽  
Author(s):  
Yara Saleh ◽  
Sébastien Antherieu ◽  
Romain Dusautoir ◽  
Laurent Y. Alleman ◽  
Jules Sotty ◽  
...  
Keyword(s):  
Ultrafine Particles ◽  
Chronic Exposure ◽  
Time Course ◽  
Fine Particles ◽  
Respiratory Health ◽  
Wall Thickening ◽  
Alveolar Wall ◽  
Similar Chemical ◽  
Time Course Experiment ◽  
Severe Lung

Exposure to particulate matter (PM) is leading to various respiratory health outcomes. Compared to coarse and fine particles, less is known about the effects of chronic exposure to ultrafine particles, despite their higher number and reactivity. In the present study, we performed a time-course experiment in mice to better analyze the lung impact of atmospheric ultrafine particles, with regard to the effects induced by fine particles collected on the same site. Trace element and PAH analysis demonstrated the almost similar chemical composition of both particle fractions. Mice were exposed intranasally to FF or UFP according to acute (10, 50 or 100 µg of PM) and repeated (10 µg of PM 3 times a week during 1 or 3 months) exposure protocols. More particle-laden macrophages and even greater chronic inflammation were observed in the UFP-exposed mice lungs. Histological analyses revealed that about 50% of lung tissues were damaged in mice exposed to UFP for three months versus only 35% in FF-exposed mice. These injuries were characterized by alveolar wall thickening, macrophage infiltrations, and cystic lesions. Taken together, these results strongly motivate the update of current regulations regarding ambient PM concentrations to include UFP and limit their emission.

scholarly journals Expression and Processing of Proteins Encoded by the Saccharomyces Retrotransposon Ty5

2001 ◽  
Vol 75 (4) ◽  
pp. 1790-1797 ◽  
Author(s):  
Phillip A. Irwin ◽  
Daniel F. Voytas
Keyword(s):  
Reverse Transcriptase ◽  
Time Course ◽  
Immunoblot Analysis ◽  
Proteolytic Processing ◽  
Coding Region ◽  
Reading Frame ◽  
C Terminus ◽  
Virus Like Particle ◽  
Ionic Detergent ◽  
Time Course Experiment

ABSTRACT Retroelements (retrotransposons and retroviruses) have two genes in common: gag, which specifies structural proteins that form a virus or virus-like particle, andpol, which specifies catalytic proteins required for replication. For many retroelements, gag andpol are present on separate reading frames. Their expression is highly regulated, and the ratio of Gag to Pol is critical for retroelement replication. The Saccharomycesretrotransposon Ty5 contains a single open reading frame, and we characterized Gag and Pol expression by generating transpositionally active Ty5 elements with epitope tags at the N terminus or C terminus or within the integrase coding region. Immunoblot analysis identified two Gag species (Gag-p27 and Gag-p37), reverse transcriptase (Pol-p59), and integrase (Pol-p80), all of which are largely insoluble in the absence of urea or ionic detergent. These proteins result from proteolytic processing of a polyprotein, because elements with mutations in the presumed active site of Ty5 protease express a single tagged protein (Gag-Pol-p182). Protease mutants are also transpositionally inactive. In a time course experiment, we monitored protein expression, proteolytic processing, and transposition of a Ty5 element with identical epitope tags at its N and C termini. Both transposition and the abundance of Gag-p27 increased over time. In contrast, the levels of Gag-p37 and reverse transcriptase peaked after ∼14 h of induction and then gradually decreased. This may be due to differences in stability of Gag-p27 relative to Gag-p37 and reverse transcriptase. The ratio of Ty5 Gag to Pol averaged 5:1 throughout the time course experiment, suggesting that differential protein stability regulates the amounts of these proteins.

scholarly journals Effects of aminoethoxyvinylglycine treatments on pre-harvest fruit drop and fruit quality of Braeburn apples

2018 ◽  
Vol 44 (2) ◽  
pp. 299-307
Author(s):  
Burhan Ozturk ◽  
Kenan Yildiz ◽  
Yakup Ozkan ◽  
Kemal Kilic
Keyword(s):  
Fruit Quality ◽  
Ethylene Biosynthesis ◽  
Quality Parameters ◽  
Control Treatment ◽  
Starch Degradation ◽  
Naphthaleneacetic Acid ◽  
Fruit Peel ◽  
Fruit Removal ◽  
Peel Color ◽  
Second Year

This study was conducted to determine the effects of increasing aminoethoxyvinylglycine (AVG) concentrations on pre-harvest drop and fruit quality parameters of ‘Braeburn’ apples. Results revealed that AVG treatments increased the fruit removal force and significantly decreased pre-harvest drops compared to control treatment. AVG was found to be more effective in controlling pre-harvest drops than naphthaleneacetic acid (NAA). There were significant differences among AVG doses with regard to preharvest drop rates. The lowest ratio of pre-harvest drop was observed in 400 mg/l AVG treatment. All AVG doses decreased ethylene biosynthesis. Inhibition of ethylene biosynthesis was higher in 300 and 400 mg/l AVG treatments than the other AVG treatment. AVG retarded fruit ripening of ‘Braeburn’ apples. Measurements, performed at different dates of ripening process, revealed higher flesh firmness values for AVG-treated fruits than the control. Starch degradation was delayed by AVG treatments. Effects of AVG on fruit peel color varied with years. While significant effects of AVG treatments on peel color were not observed in the first year, especially higher AVG doses significantly increased L* values and hue angles in the second year. AVG treatments also significantly increased fruit mass in both years. Significant changes in fruit geometric diameters were not observed with AVG treatments, except for 300 mg/l AVG treatment of second year.

scholarly journals Survival of halophilic Archaea in Earth's cold stratosphere

2016 ◽  
Vol 16 (4) ◽  
pp. 321-327 ◽  
Author(s):  
P. DasSarma ◽  
V.J. Laye ◽  
J. Harvey ◽  
C. Reid ◽  
J. Shultz ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Cold Adaptation ◽  
Halophilic Archaea ◽  
Cold Temperature ◽  
Freezing And Thawing ◽  
Cold Adapted ◽  
Liquid Cultures ◽  
Genome Wide ◽  
Temperature Exposure ◽  
Genetic Responses

AbstractHalophilic Archaea are known to tolerate multiple extreme conditions on Earth and have been proposed as models for astrobiology. In order to assess the importance of cold-adaptation of these microorganisms in surviving stratospheric conditions, we launched live, liquid cultures of two species, the mesophilic model Halobacterium sp. NRC-1 and the cold-adapted Antarctic isolate Halorubrum lacusprofundi ATCC 49239, on helium balloons. After return to Earth, the cold-adapted species showed nearly complete survival while the mesophilic species exhibited slightly reduced viability. Parallel studies found that the cold-adapted species was also better able to survive freezing and thawing in the laboratory. Genome-wide transcriptomic analysis was used to compare the two haloarchaea at optimum growth temperatures versus low temperatures supporting growth. The cold-adapted species displayed perturbation of a majority of genes upon cold temperature exposure, divided evenly between up-regulated and down-regulated genes, while the mesophile exhibited perturbation of only a fifth of its genes, with nearly two-thirds being down-regulated. These results underscore the importance of genetic responses of H. lacusprofundi to cold temperature for enhanced survival in the stratosphere.

Detoxification of succinate semialdehyde in Arabidopsis glyoxylate reductase and NAD kinase mutants subjected to submergence stress

Botany ◽  
2012 ◽  
Vol 90 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Wendy L. Allan ◽  
Kevin E. Breitkreuz ◽  
Jeffrey C. Waller ◽  
Jeffrey P. Simpson ◽  
Gordon J. Hoover ◽  
...  
Keyword(s):  
Time Course ◽  
Oxygen Deficiency ◽  
Transcript Abundance ◽  
Redox Status ◽  
Nad Kinase ◽  
Submergence Stress ◽  
Succinate Semialdehyde ◽  
Biochemical Mechanisms ◽  
Glyoxylate Reductase

Succinate semialdehyde (SSA) is a mitochondrially generated intermediate in the metabolism of γ-aminobutyrate (GABA), which accumulates in response to a variety of biotic and abiotic stresses. SSA can be reduced to γ-hydroxybutyrate (GHB) in plants exposed to various abiotic stress conditions. Recent evidence indicates that distinct cytosolic and plastidial glyoxylate reductase isoforms from Arabidopsis thaliana (L.) Heynh (GLYR1 and GLYR2, respectively) catalyze the in vitro conversion of SSA to GHB, as well as glyoxylate to glycolate, via NADPH-dependent reactions. In the present study, recombinant Arabidopsis GLYR1 was demonstrated to catalyze the NADPH-dependent reduction of both glyoxylate and SSA simultaneously to glycolate and GHB, respectively. Six-hour time-course experiments with intact vegetative wild-type Arabidopisis plants subjected to submergence demonstrated that GHB accumulates in rosette leaves, and this is accompanied by increasing levels of GABA and alanine, NADH/NAD+ and NADPH/NADP+ ratios, and GLYR1 and GLYR2 transcript abundance. The use of GLYR (glyr1 or glyr2 knockout) and NAD kinase1 (NADK1 suppression or overexpression) mutants demonstrated that under submergence the production of GHB is mediated via both GLYR isoforms, the loss of either GLYR1 or GLYR2 activity influences redox status and the levels of GABA and alanine, and the manipulation of NADP(H) availability, specifically in the cytosol, influences the production of GHB. These results suggest that biochemical mechanisms are more important than transcriptional mechanisms in the regulation of GLYR activity and SSA detoxification in plants during the onset of submergence-induced oxygen deficiency.

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