Dietary zinc potentiates thermal tolerance and cellular stress protection of Pangasius hypophthalmus reared under lead and thermal stress

2017 ◽  
Vol 49 (2) ◽  
pp. 1105-1115 ◽  
Author(s):  
Neeraj Kumar ◽  
Kishore K Krishnani ◽  
Nitish K Chandan ◽  
Narendra P Singh
Keyword(s):  
Thermal Stress ◽  
Thermal Tolerance ◽  
Cellular Stress ◽  
Dietary Zinc ◽  
Stress Protection

scholarly journals Thermal stress and physiological changes in watermelon seeds

2018 ◽  
Vol 48 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Rita de Cássia Barbosa da Silva ◽  
Marcelo do Nascimento Araujo ◽  
Fábio Luiz Santos Ornellas ◽  
Bárbara França Dantas
Keyword(s):  
Enzyme Activity ◽  
Thermal Stress ◽  
Germination Rate ◽  
Germination Percentage ◽  
Initial Growth ◽  
Physiological Changes ◽  
Percentage Germination ◽  
Stress Protection ◽  
Evaluation Parameters ◽  
The Ideal

ABSTRACT Given that watermelon is a crop widespread around the world, there is considerable interest in verifying how its seeds physiologically behave under unfavorable temperature conditions. This study aimed to evaluate the biochemical changes mobilization and reserves degradation, as well as the enzyme activity, during seed germination and initial growth of watermelon seedlings subjected to thermal stress, using temperature, germination percentage, germination rate and relative germination frequency over the incubation time as evaluation parameters. The experimental design was completely randomized, in a 5 x 3 factorial scheme, with five temperatures (17 ºC, 20 ºC, 25 ºC, 30 ºC and 35 ºC) and three cultivars (Charleston Gray, Fairfax and Crimson Sweet), with 4 replicates of 50 seeds. Germination, seedling growth, reserve degradation and stress protection system were evaluated. Thermal stress caused deleterious effects on watermelon seeds with germination capacity at well defined temperature limits, being 25 ºC the ideal temperature, with the highest percentage of normal seedlings. Sub- (17 ºC) and supra-optimal (30 ºC) temperatures presented more than 80 % of abnormal seedlings. The α-amylase enzyme activity is intense only at the beginning of germination. Under thermal stress, the proline contents increase mainly in the cotyledons.

scholarly journals Nitrogen sufficiency enhances thermal tolerance in habitat-forming kelp: implications for acclimation under thermal stress

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pamela A. Fernández ◽  
Juan Diego Gaitán-Espitia ◽  
Pablo P. Leal ◽  
Matthias Schmid ◽  
Andrew T. Revill ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Thermal Tolerance

A Unifying Model to Estimate Thermal Tolerance Limits in Ectotherms Across Static, Dynamic and Fluctuating Exposures to Thermal Stress

2021 ◽  
Author(s):  
Lisa Bjerregaard Jørgensen ◽  
Hans Malte ◽  
Michael Ørsted ◽  
Nikolaj Andreasen Klahn ◽  
Johannes Overgaard
Keyword(s):  
Thermal Stress ◽  
Thermal Tolerance ◽  
Input Data ◽  
Thermal Injury ◽  
Accumulation Rate ◽  
Temperature Tolerance ◽  
Separate Experiment ◽  
Tolerance Limits ◽  
Dynamic Experiments ◽  
Different Temperatures

Abstract Temperature tolerance is critical for defining the fundamental niche of ectotherms and researchers classically use either static (exposure to a constant temperature) or dynamic (ramping temperature) assays to assess tolerance. The use of different methods complicates comparison between studies and here we present mathematical model (and R-scripts) to reconcile thermal tolerance measures obtained from static and dynamic assays. Our model uses input data from several static or dynamic experiments and is based on the well-supported assumption that thermal injury accumulation rate increases exponentially with temperature (recently re-introduced as Thermal Tolerance Landscapes). The model also assumes thermal stress at different temperatures to be additive and using experiments with Drosophila melanogaster, we validate these central assumptions by demonstrating that heat injury attained at different heat stress intensities and durations is additive. In a separate experiment we demonstrate that our model can accurately describe injury accumulation during fluctuating temperature stress and further we validate the model by successfully converting literature data of ectotherm heat tolerance (both static and dynamic assays) to a single, comparable metric (the temperature tolerated for 1 hour). The model presented here has many promising applications for the analysis of ectotherm thermal tolerance and we also discuss potential pitfalls that should be considered and avoided using this model.

Influence of osmotic stress on upper lethal temperatures in the cyprinodontid fish Fundulus heteroclitus (L.)

1972 ◽  
Vol 50 (6) ◽  
pp. 787-791 ◽  
Author(s):  
E. T. Garside ◽  
Z. K. Chin-Yuen-Kee
Keyword(s):  
Thermal Stress ◽  
Osmotic Stress ◽  
Fresh Water ◽  
Thermal Tolerance ◽  
Fundulus Heteroclitus ◽  
Thermal Acclimation ◽  
Lethal Temperature ◽  
Lethal Temperatures

Upper lethal temperatures determined for the mummichog Fundulus heteroclitus (L.) for exposures of 10 000 min ranged from 18.58C to 36.31C. Osmotic acclimations were prepared at 0, 14, and 32‰ salinity (S), at thermal acclimations of 5 and 15C, and at 14 and 32‰ S at 25C. Mummichog could not survive in the acclimatory combination of 0‰ S at 25C. Subsamples from these acclimatory combinations were exposed to thermal stress at 0, 14, and 32‰ S. Highest upper lethal temperatures were observed in isosmotic test salinity (14‰). Intermediate lethal levels occurred in seawater (32‰ S) and the lowest lethal temperatures occurred in fresh water (0‰ S). Upper lethal temperature increased with increasing thermal acclimation but generally, prior osmotic experience did not modify thermal tolerance. There was no relation between order of death and size in 18 of the 24 test combinations. In the remaining six, the largest members died first in four and the smallest died first in two test combinations.

Responses of dauerlarvae of Caenorhabditis elegans (Nematoda: Rhabditidae) to thermal stress and oxygen deprivation

1978 ◽  
Vol 56 (8) ◽  
pp. 1786-1791 ◽  
Author(s):  
Gary L. Anderson
Keyword(s):  
Thermal Stress ◽  
Caenorhabditis Elegans ◽  
Developmental Stage ◽  
Thermal Tolerance ◽  
Oxygen Deprivation ◽  
Behavior Changes ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living ◽  
Anaerobic Stress ◽  
Free Living Nematode

Larval forms of the free-living nematode Caenorhabditis elegans possess the ability to enter a developmental stage which is thought to be specialized for survival in harsh environmental conditions, i.e. the dauerlarval stage. In this study the responses of dauerlarvae to thermal stress and oxygen deprivation are investigated. Oxygen consumption of dauerlarvae is less sensitive to temperature change that that of adults, with Q10 values of 1.7 and 2.6 respectively. The upper thermal tolerance limit of dauerlarvae is also different from that of adults; dauerlarvae survive approximately three times longer than adults when exposed to 37 °C. In addition to differences in thermal tolerance, dauerlarvae survive longer under anaerobic conditions than adults, 7 days and 2 days respectively. On recovery from anaerobic stress dauerlarvae exhibit behavior changes which are suggestive of emergence from the dauerlarval stage. The responses of dauerlarvae to thermal stress and oxygen deprivation appear to be important aspects of the specialization for survival in this facultative developmental stage.

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