cold stress Dotaz Zobrazit nápovědu
- MeSH
- experimenty na zvířatech MeSH
- fyziologický stres MeSH
- metabolismus MeSH
- nízká teplota MeSH
- skot MeSH
- Check Tag
- skot MeSH
- MeSH
- Aspirin MeSH
- dítě MeSH
- fyziologický stres MeSH
- nízká teplota MeSH
- předloktí MeSH
- prsty ruky MeSH
- teplota kůže MeSH
- Check Tag
- dítě MeSH
- MeSH
- fosfolipidy metabolismus MeSH
- křečci praví MeSH
- nízká teplota MeSH
- noradrenalin MeSH
- Check Tag
- křečci praví MeSH
- Publikační typ
- srovnávací studie MeSH
Analysis of sublethal responses in cold-stressed insects can provide important information about fitness costs and a better understanding of the physiological mechanisms used to prevent and/or to cope with cold injury. Yet, such responses are understudied and often neglected in the literature. Here, we analyzed the effects of cold stress applied to larvae on the mortality/survival and fitness parameters of survivor adults of the vinegar fly, Drosophila melanogaster. Third instar larvae (either cold-sensitive or cold-acclimated) were exposed to either supercooling or freezing stress, both at -5 °C. A whole array of sublethal effects were observed, from mortality that occurs with some delay after cold stress, through delayed development to the pupal stage, to shortened life-span of the adult, and decreased female fecundity. Taking the sublethal effects into account improves the ecological meaningfulness of cold hardiness assay outcomes. For instance, we observed that although more than 80% of cold-acclimated larvae survive freezing to -5 °C, less than 10% survive until adulthood, and survivor females exhibit more than 50% reduction in their fecundity relative to controls. Female fecundity was positively correlated with dry mass and negatively correlated with total protein and glycogen stores. Hence, these parameters may serve as good predictors of survivor adult female fecundity. Further, we provide the concept of a two-component defense system, which (based on analysis of sublethal effects on fitness parameters) distinguishes between physiological mechanisms that help insects to resist (reduce or avoid) or tolerate (survive or repair) injuries linked to cold stress.
As sessile organisms, plants are unable to escape from the many abiotic and biotic factors that cause a departure from optimal conditions of growth and development. Low temperature represents one of the most harmful abiotic stresses affecting temperate plants. These species have adapted to seasonal variations in temperature by adjusting their metabolism during autumn, increasing their content of a range of cryo-protective compounds to maximise their cold tolerance. Some of these molecules are synthesised de novo. The down-regulation of some gene products represents an additional important regulatory mechanism. Ways in which plants cope with cold stress are described, and the current state of the art with respect to both the model plant Arabidopsis thaliana and crop plants in the area of gene expression and metabolic pathways during low-temperature stress are discussed.
- MeSH
- aklimatizace fyziologie MeSH
- Arabidopsis genetika metabolismus fyziologie MeSH
- fyziologický stres fyziologie MeSH
- nízká teplota MeSH
- regulace genové exprese u rostlin MeSH
- rostlinné proteiny genetika metabolismus MeSH
- signální transdukce MeSH
- transkripční faktory genetika metabolismus MeSH
- zemědělské plodiny metabolismus fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
