scholarly journals Freezing stress damage and growth viability in Vaccinium macrocarpon Ait. bud structures

2021 ◽  
Author(s):  
Camilo Villouta ◽  
Beth Ann Workmaster ◽  
Amaya Atucha
Keyword(s):  
Vaccinium Macrocarpon ◽  
Freezing Stress ◽  
Stress Damage

scholarly journals Freezing stress survival mechanisms in Vaccinium macrocarpon Ait. terminal buds

2020 ◽  
Vol 40 (7) ◽  
pp. 841-855
Author(s):  
Camilo Villouta ◽  
Beth Ann Workmaster ◽  
Jenny Bolivar-Medina ◽  
Smith Sinclair ◽  
Amaya Atucha
Keyword(s):  
Cold Hardiness ◽  
Liquid Water Content ◽  
Vaccinium Macrocarpon ◽  
Freezing Stress ◽  
Cold Temperatures ◽  
Woody Perennial ◽  
Stress Survival ◽  
Mri Scans ◽  
Terminal Buds ◽  
Controlled Freezing

Abstract Plants’ mechanisms for surviving freezing stresses are essential adaptations that allow their existence in environments with extreme winter temperatures. Although it is known that Vaccinium macrocarpon Ait. buds can acclimate in fall and survive very cold temperatures during the winter, the mechanism for survival of these buds is not known. The main objective of this study was to determine which of the two major mechanisms of freezing stress survival, namely, deep supercooling or freeze-induced dehydration, are employed by V. macrocarpon terminal buds. In the present study, no low-temperature exotherms (LTEs) were detected by differential thermal analysis. Furthermore, a gradual reduction of relative liquid water content in the inner portions of buds during magnetic resonance imaging (MRI) scans performed between 0 and −20 °C (where no damage was detected in controlled freezing tests (CFT)) indicates these buds may not deep supercool. The higher ice nucleation activity of outer bud scales and the appearance of large voids in this structure in early winter, in conjunction with the MRI observations, are evidence supportive of a freeze-induced dehydration process. In addition, the presence of tissue browning in acclimated buds as a result of freezing stress was only observed in CFT at temperatures below −20 °C, and this damage gradually increased as test temperatures decreased and at different rates depending on the bud structure. Ours is the first study to collect multiple lines of evidence to suggest that V. macrocarpon terminal buds survive long periods of freezing stress by freeze-induced dehydration. Our results provide a framework for future studies of cold hardiness dynamics for V. macrocarpon and other woody perennial species and for the screening of breeding populations for freezing stress tolerance traits.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

Physical exercise protects dynamic balance and motor coordination of rats treated with vincristine

2020 ◽  
Vol 19 (5) ◽  
pp. 336
Author(s):  
Luiza Minato Sagrillo ◽  
Viviane Nogueira De Zorzi ◽  
Luiz Fernando Freire Royes ◽  
Michele Rechia Fighera ◽  
Beatriz Da Silva Rosa Bonadiman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Locomotor Activity ◽  
Physical Exercise ◽  
Motor Coordination ◽  
Dynamic Balance ◽  
Exercise Group ◽  
Adult Rats ◽  
The Central Nervous System ◽  
Stress Damage ◽  
Training Protocol

Physical exercise has been shown to be an important modulator of the antioxidant system and neuroprotective in several diseases and treatments that affect the central nervous system. In this sense, the present study aimed to evaluate the effect of physical exercise in dynamic balance, motor coordination, exploratory locomotor activity and in the oxidative and immunological balance of rats treated with vincristine (VCR). For that, 40 adult rats were divided into two groups: exercise group (6 weeks of swimming, 1h/day, 5 days/week, with overload of 5% of body weight) and sedentary group. After training, rats were treated with 0.5 mg/kg of vincristine sulfate for two weeks or with the same dose of 0.9% NaCl. The behavioral tests were conducted 1 and 7 days after each dose of VCR. On day 15 we carried out the biochemical analyzes of the cerebellum. The physical exercise was able to protect against the loss of dynamic balance and motor coordination and, had effect per se in the exploratory locomotor activity, and neutralize oxidative stress, damage DNA and immune damage caused by VCR up to 15 days after the end of the training protocol. In conclusion, we observed that previous physical training protects of the damage motor induced by vincristine.Key-words: exercise, oxidative stress, neuroprotection, cerebellum.

TaPK-R1 Overexpressing Transgenic Wheat Lines Enhance Resistance to Sharp Eyespot and Freezing Stress

2016 ◽  
Vol 42 (11) ◽  
pp. 1601
Author(s):  
Mei-Ying LUO ◽  
Wei RONG ◽  
Xue-Ning WEI ◽  
Kun YANG ◽  
Hui-Jun XU ◽  
...  
Keyword(s):  
Transgenic Wheat ◽  
Freezing Stress ◽  
Sharp Eyespot ◽  
Wheat Lines

Idebenone Treatment Mediates the Effect of Menadione Oxidative Stress Damage in Saccharomyces cerevisiae

2012 ◽  
Vol 6 (2) ◽  
pp. 120-123 ◽  
Author(s):  
Oliver Gamondi ◽  
Sebastian Chapela ◽  
Ines Nievas ◽  
Isabel Burgos ◽  
Manuel Alonso ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Stress Damage

The Impact of L-Carnitine and Coenzyme Q10 as Protection Against Busulfan-Oxidative Stress in the Liver of Adult Rats

2020 ◽  
Vol 10 (5) ◽  
pp. 578-586
Author(s):  
Areeg M. Abdelrazek ◽  
Shimaa A. Haredy
Keyword(s):  
Oxidative Stress ◽  
Coenzyme Q10 ◽  
Protective Role ◽  
Albino Rats ◽  
Distilled Water ◽  
Negative Effects ◽  
Adult Rats ◽  
Stress Damage ◽  
The Impact ◽  
Liver Tissues

Background: Busulfan (Bu) is an anticancer drug with a variety of adverse effects for cancer patients. Oxidative stress has been considered as a common pathological mechanism and it has a key role in the initiation and progression of liver injury by Bu. Aim: The study aimed to evaluate the antioxidant impact of L-Carnitine and Coenzyme Q10 and their protective role against oxidative stress damage in liver tissues. Methods and Material: Thirty-six albino rats were divided equally into six groups. G1 (con), received I.P. injection of DMSO plus 1 ml of distilled water daily by oral gavages; G2 (Bu), received I.P. injection of Bu plus 1 ml of the distilled water daily; G3 (L-Car), received 1 ml of L-Car orally; G4 (Bu + L-Car) received I.P. injection of Bu plus 1 ml of L-Car, G5 (CoQ10) 1 ml of CoQ10 daily; and G6 (Bu + CoQ10) received I.P. injection of Bu plus 1 ml of CoQ10 daily. Results: The recent data showed that Bu induced significant (P<0.05) elevation in serum ALT, AST, liver GSSG, NO, MDA and 8-OHDG, while showing significant (P<0.05) decrease in liver GSH and ATP. On the other hand, L-Carnitine and Coenzyme Q10 ameliorated the negative effects prompted by Bu. Immunohistochemical expression of caspase-3 in liver tissues reported pathological alterations in Bu group while also showed significant recovery in L-Car more than CoQ10. Conclusion: L-Car, as well as CoQ10, can enhance the hepatotoxic effects of Bu by promoting energy production in oxidative phosphorylation process and by scavenging the free radicals.

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