autumn senescence Dotaz Zobrazit nápovědu
Cytokinins are plant hormones that typically block or delay leaf senescence. We profiled 34 different cytokinins/cytokinin metabolites (including precursors, conjugates and degradation products) in leaves of a free-growing mature aspen (Populus tremula) before and after the initiation of autumnal senescence over three consecutive years. The levels and profiles of individual cytokinin species, or classes/groups, varied greatly between years, despite the fact that the onset of autumn senescence was at the same time each year, and senescence was not associated with depletion of either active or total cytokinin levels. Levels of aromatic cytokinins (topolins) were low and changed little over the autumn period. Diurnal variations and weather-dependent variations in cytokinin content were relatively limited. We also followed the expression patterns of all aspen genes implicated as having roles in cytokinin metabolism or signalling, but neither the pattern of regulation of any group of genes nor the expression of any particular gene supported the notion that decreased cytokinin signalling could explain the onset of senescence. Based on the results from this tree, we therefore suggest that cytokinin depletion is unlikely to explain the onset of autumn leaf senescence in aspen.
- MeSH
- biosyntetické dráhy genetika MeSH
- chlorofyl metabolismus MeSH
- cytokininy metabolismus MeSH
- down regulace genetika MeSH
- glukosidy metabolismus MeSH
- listy rostlin metabolismus fyziologie MeSH
- počasí MeSH
- Populus genetika metabolismus fyziologie MeSH
- regulace genové exprese u rostlin MeSH
- roční období MeSH
- rostlinné geny MeSH
- stanovení celkové genové exprese MeSH
- Publikační typ
- časopisecké články MeSH
Starý človek aj v jeseni života zostáva človekom, je jedinečným a neopakovateľným, má ľudskú dôstojnosť. Vie, že na zemi nežije sám, že ho obklopuje spoločenstvo iných ľudí. Svoju veľkosť prežíva pri stretnutí s iným človekom, pri stretnutí so sebou samým a najmä v hraničných situáciách života a smrti.
Old man remains a man even in the autumn of life, is unique and nonrecurring, and has a human dignity. He knows he does not live on Earth alone, that a community of other people surrounds him. He lives his greatness with encounter with other man, with encounter with himself and mostly in borderline situations of life and death.
- MeSH
- domovy pro seniory * MeSH
- kvalita života MeSH
- lidé středního věku MeSH
- lidé MeSH
- průzkumy a dotazníky MeSH
- senioři nad 80 let MeSH
- senioři * MeSH
- sociální péče klasifikace trendy zákonodárství a právo MeSH
- sociální podmínky * MeSH
- stárnutí * MeSH
- životní styl MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři * MeSH
- ženské pohlaví MeSH
- Geografické názvy
- Slovenská republika MeSH
