Cold exposure depolarizes cells in insects due to a reduced electrogenic ion transport and a gradual increase in extracellular K+ concentration ([K+]). Cold-induced depolarization is linked to cold injury in chill-susceptible insects, and the locust, Locusta migratoria, has been shown to improve cold tolerance following cold acclimation through depolarization resistance. Here we investigate how cold acclimation influences depolarization resistance and how this resistance relates to improved cold tolerance. To address this question, we investigated if cold acclimation affects the electrogenic transport capacity and/or the relative K+ permeability during cold exposure by measuring membrane potentials of warm- and cold-acclimated locusts in the presence and absence of ouabain (Na+-K+ pump blocker) or 4-aminopyridine (4-AP; voltage-gated K+ channel blocker). In addition, we compared the membrane lipid composition of muscle tissue from warm- and cold-acclimated locust and the abundance of a range transcripts related to ion transport and cell injury accumulation. We found that cold-acclimated locusts are depolarization resistant due to an elevated K+ permeability, facilitated by opening of 4-AP-sensitive K+ channels. In accordance, cold acclimation was associated with an increased abundance of Shaker transcripts (gene encoding 4-AP-sensitive voltage-gated K+ channels). Furthermore, we found that cold acclimation improved muscle cell viability following exposure to cold and hyperkalemia even when muscles were depolarized substantially. Thus cold acclimation confers resistance to depolarization by altering the relative ion permeability, but cold-acclimated locusts are also more tolerant to depolarization.
- MeSH
- 4-aminopyridin farmakologie MeSH
- aklimatizace účinky léků fyziologie MeSH
- kosterní svalová vlákna účinky léků fyziologie MeSH
- Locusta migratoria fyziologie MeSH
- membránové potenciály účinky léků fyziologie MeSH
- nízká teplota * MeSH
- ouabain farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The benefits of in vitro plant cultivation are mainly due to very high multiplication rate. Cultivation of plant material in vitro can be carried out during the whole year regardless of the time of the year or weather conditions. We create artificial conditions in the lab (heat, light, humidity), and we can regulate these conditions at any time. For the preservation of cultivar identity, we recommend establishing in vitro cultures from shoot tips usually larger than 0.2 mm. In practice, in vitro cultivation of plants uses these growth regulators to achieve organogenesis, for example, root formation, prolonged growth, or multiplication. During each subculture, these cultures are then transferred on a solid agar medium in the form of actively growing multiple shoots with a well-differentiated shoot tip containing meristematic area. Cytokinins are important for cell division and causes branching of plants. Auxins, both endogenous and exogenous, act at as a trigger for the differentiation and formation of root primordia. Morphological characteristics (formation of leaves or callus) and shoot development should be observed during in vitro multiplication and after transfer to ex vitro conditions.
- MeSH
- aklimatizace fyziologie MeSH
- cytokininy farmakologie MeSH
- kultivační média chemie farmakologie MeSH
- kyseliny indoloctové farmakologie MeSH
- meristém účinky léků růst a vývoj MeSH
- proliferace buněk účinky léků fyziologie MeSH
- regulátory růstu rostlin farmakologie MeSH
- Rosaceae účinky léků růst a vývoj MeSH
- techniky in vitro MeSH
- techniky tkáňových kultur metody MeSH
- výhonky rostlin účinky léků růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species.
- MeSH
- aklimatizace fyziologie MeSH
- časové faktory MeSH
- fenotyp * MeSH
- klimatické změny * MeSH
- ptáci fyziologie MeSH
- selekce (genetika) fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- systematický přehled MeSH
Although plants are often exposed to atmospheric nanoparticles (NPs), the mechanism of NP deposition and their effects on physiology and metabolism, and particularly in combination with other stressors, are not yet understood. Exploring interactions between stressors is particularly important for understanding plant responses in urban environments where elevated temperatures can be associated with air pollution. Accordingly, 3-year-old spruce seedlings were exposed for 2 weeks to aerial cadmium oxide (CdO) NPs of environmentally relevant size (8-62 nm) and concentration (2 × 105 cm-3). While half the seedlings were initially acclimated to high temperature (35 °C) and vapour pressure deficit (VPD; 2.81 kPa), the second half of the plants were left under non-stressed conditions (20 °C, 0.58 kPa). Atomic absorption spectrometry was used to determine Cd content in needles, while gas and liquid chromatography was used to determine changes in primary and secondary metabolites. Photosynthesis-related processes were explored with gas-exchange and chlorophyll fluorescence systems. Our work supports the hypothesis that atmospheric CdO NPs penetrate into leaves but high temperature and VPD reduce such penetration due to stomatal closure. The hypothesis that atmospheric CdO NPs influences physiological and metabolic processes in plants was also confirmed. This impact strengthens with increasing time of exposure. Finally, we found evidence that plants acclimated to stress conditions have different sensitivity to CdO NPs compared to plants not so acclimated. These findings have important consequences for understanding impacts of global warming on plants and indicates that although the effects of elevated temperatures can be deleterious, this may limit other forms of plant stress associated with air pollution.
- MeSH
- aklimatizace fyziologie MeSH
- borovice MeSH
- fotosyntéza fyziologie MeSH
- globální oteplování MeSH
- jedle MeSH
- látky znečišťující vzduch toxicita MeSH
- látky znečišťující životní prostředí metabolismus MeSH
- listy rostlin účinky léků MeSH
- nanočástice toxicita MeSH
- oxidy toxicita MeSH
- semenáček účinky léků MeSH
- sloučeniny kadmia toxicita MeSH
- smrk účinky léků fyziologie MeSH
- teplota * MeSH
- vysoká teplota MeSH
- Publikační typ
- časopisecké články MeSH
The bean bug (Riptortus pedestris) is a pest of soybeans and other legumes in Japan and other Asian countries. It enters a facultative adult diapause on exposure to short days. While photoperiodism and diapause are well understood in R. pedestris, knowledge of cold tolerance is very limited, as is information on the effect of diapause on cold tolerance. We examined the effect of photoperiod, cold acclimation, and feeding status on cold tolerance in R. pedestris. We found that cold acclimation significantly increased survival at -10°C in both long- and short-day adult R. pedestris. Since the difference in cold survival between long- and short-day cold-acclimated groups was only marginal, we conclude that entering diapause is not crucial for R. pedestris to successfully pass through cold acclimation and become cold tolerant. We observed similar effects in 5th instar nymphs, with both long- and short-day cold-acclimated groups surviving longer cold exposures compared with non-acclimated groups. Starvation, which was tested only in adult bugs, had only a negligible and negative impact on cold survival. Although cold tolerance significantly increased with cold acclimation in adult bugs, supercooling capacity unexpectedly decreased. Our results suggest that changes in supercooling capacity as well as in water content are unrelated to cold tolerance in R. pedestris. An analysis of metabolites revealed differences between the treatments, and while several metabolites markedly increased with cold acclimation, their concentrations were too low to have a significant effect on cold tolerance.
- MeSH
- aklimatizace * fyziologie MeSH
- diapauza hmyzu fyziologie MeSH
- Heteroptera metabolismus fyziologie MeSH
- metabolomika MeSH
- nízká teplota škodlivé účinky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The purpose of our pilot study was to find out if total body water (TBW) changes could objectively modify the course of adaptation during training for elite runners at different altitudes. The aim of this pilot study is to summarize the indication of the progress of acclimatization at high altitudes (1000–2700 meters above sea level) during alpine conditioning. In three training camps at various altitudes the TBW of elite runners (F = 3, M = 1; n = 4; age 23 ± 0.9) was monitored, in order to check the progress of acclimatization. We used BIA measurement methods (Bodystat 1500) at different high altitude running camps at the Czech Republic, Morocco and Ethiopia. Changes in TBW were used to check the progress of acclimatization. We discovered that the retention peaks of TBW corresponded with critical days (p ≤ 0.04; Cohen’s d). The highest measured increases of TBW at an altitude of 1000 m were for runner 1, 1.7 litres and for runner 2, 2.1 litres with retention peaks for both occurring on the 5th day. At an altitude of 1770 m runner 1 reached an increase of TBW of 6.3 litres, with a retention peak on the 11th day, and runner 3 had an increase of 5.1 litres with a peak on the 8th day. In the acclimatization phase we found two critical periods, from the 4th–6th day, and after the 10th–12th day. For runner 4 in altitude 2700m who completed the camp at a higher altitude, the situation is more complicated because there were fluctuations of the content of TBW in the range of 1.25 litres, with the highest depression on the 5th and then again an unsettled rise and reaching a maximum on the 12th, when she nearly returned to the initial value. Detected retention peaks reflected different levels of altitude (5th–12th days).We can conclude that the measuring of changes in TBW during camps at higher altitudes may be one of the biomarkers during acclimatization to altitude.
- Klíčová slova
- celková tělesná voda,
- MeSH
- aklimatizace * fyziologie MeSH
- běh fyziologie MeSH
- časové faktory MeSH
- elektrická impedance MeSH
- fyzická vytrvalost fyziologie MeSH
- lehká atletika * fyziologie MeSH
- lidé MeSH
- mladý dospělý MeSH
- nadmořská výška MeSH
- pilotní projekty MeSH
- sportovní výkon MeSH
- tělesná voda * MeSH
- Check Tag
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Klíčová slova
- vysokohorské prostředí,
- MeSH
- aklimatizace fyziologie MeSH
- energetický metabolismus MeSH
- fyziologická adaptace MeSH
- hypoxie MeSH
- kritický stav MeSH
- lidé MeSH
- mikrocirkulace MeSH
- nadmořská výška MeSH
- urgentní lékařství MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- souhrny MeSH
- MeSH
- acetazolamid terapeutické užití MeSH
- aklimatizace fyziologie MeSH
- ataxie etiologie MeSH
- bolesti hlavy etiologie farmakoterapie MeSH
- dexamethason terapeutické užití MeSH
- edém mozku etiologie MeSH
- fyziologická adaptace MeSH
- hypoxie MeSH
- ibuprofen terapeutické užití MeSH
- kombinovaná terapie MeSH
- lidé MeSH
- nadmořská výška MeSH
- nifedipin terapeutické užití MeSH
- plicní edém etiologie MeSH
- premedikace MeSH
- výšková nemoc * diagnóza klasifikace patofyziologie prevence a kontrola terapie MeSH
- Check Tag
- lidé MeSH
Insect cold tolerance depends on their ability to withstand or repair perturbations in cellular homeostasis caused by low temperature stress. Decreased oxygen availability (hypoxia) can interact with low temperature tolerance, often improving insect survival. One mechanism proposed for such responses is that whole-animal cold tolerance is set by a transition to anaerobic metabolism. Here, we provide a test of this hypothesis in an insect model system (Thaumatotibia leucotreta) by experimental manipulation of oxygen availability while measuring metabolic rate, critical thermal minimum (CTmin), supercooling point and changes in 43 metabolites in moth larvae at three key timepoints (before, during and after chill coma). Furthermore, we determined the critical oxygen partial pressure below which metabolic rate was suppressed (c. 4.5 kPa). Results showed that altering oxygen availability did not affect (non-lethal) CTmin nor (lethal) supercooling point. Metabolomic profiling revealed the upregulation of anaerobic metabolites and alterations in concentrations of citric acid cycle intermediates during and after chill coma exposure. Hypoxia exacerbated the anaerobic metabolite responses induced by low temperatures. These results suggest that cold tolerance of T. leucotreta larvae is not set by oxygen limitation, and that anaerobic metabolism in these larvae may contribute to their ability to survive in necrotic fruit.
- MeSH
- aklimatizace fyziologie MeSH
- aminokyseliny metabolismus MeSH
- anaerobióza fyziologie MeSH
- bazální metabolismus fyziologie MeSH
- homeostáza fyziologie MeSH
- kyslík metabolismus MeSH
- larva fyziologie MeSH
- metabolomika MeSH
- můry fyziologie MeSH
- nízká teplota MeSH
- reakce na chladový šok fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
