Hormonal changes accompanying the cold stress (4°C) response that are related to the level of frost tolerance (FT; measured as LT50) and the content of the most abundant dehydrin, WCS120, were compared in the leaves and crowns of the winter wheat (Triticum aestivum L.) cv. Samanta and the spring wheat cv. Sandra. The characteristic feature of the alarm phase (1 day) response was a rapid elevation of abscisic acid (ABA) and an increase of protective proteins (dehydrin WCS120). This response was faster and stronger in winter wheat, where it coincided with the downregulation of bioactive cytokinins and auxin as well as enhanced deactivation of gibberellins, indicating rapid suppression of growth. Next, the ethylene precursor aminocyclopropane carboxylic acid was quickly upregulated. After 3-7 days of cold exposure, plant adaptation to the low temperature was correlated with a decrease in ABA and elevation of growth-promoting hormones (cytokinins, auxin and gibberellins). The content of other stress hormones, i.e., salicylic acid and jasmonic acid, also began to increase. After prolonged cold exposure (21 days), a resistance phase occurred. The winter cultivar exhibited substantially enhanced FT, which was associated with a decline in bioactive cytokinins and auxin. The inability of the spring cultivar to further increase its FT was correlated with maintenance of a relatively higher cytokinin and auxin content, which was achieved during the acclimation period.
- MeSH
- aklimatizace MeSH
- analýza hlavních komponent MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- listy rostlin enzymologie MeSH
- nízká teplota MeSH
- oxidoreduktasy metabolismus MeSH
- pšenice fyziologie MeSH
- regulátory růstu rostlin metabolismus MeSH
- roční období MeSH
- rostlinné proteiny metabolismus MeSH
- zmrazování MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The dynamics of a long-term cold acclimation (CA) was studied in spring barley cultivar Atlas 68, winter barley cultivar Igri and a set of doubled haploid (DH) lines derived from an Atlas 68xIgri cross. The aim was to evaluate the effect of plant development on the ability to induce frost tolerance (FT) and to accumulate dehydrin 5 (DHN5) during CA. The plant developmental stage was evaluated by phenological development of the shoot apex and by determination of days to heading after a certain period of CA. FT was determined by direct frost tests. Plant winter survival was also determined. DHN5 was evaluated by densitometric analysis of protein gel blots. Cold led to the induction of increased FT and to the accumulation of DHN5 in both spring and winter lines. However, with the progression of CA, differences between the growth habits occurred as the winter lines were able to maintain increased FT and DHN5 levels for a significantly longer period of time than the spring lines. After vegetative/reproductive transition, a significant decrease in DHN5 accumulation was found in all lines; however, a discrepancy between the acquired FT level and DHN5 accumulation in vernalized winter barley plants was found. A correlation between DHN5 accumulation and plant winter survival was found when the studied lines were differentiated according to their developmental stage and DHN5 level. Possible explanations for these phenomena are provided.
- MeSH
- aklimatizace genetika fyziologie MeSH
- chov MeSH
- haploidie MeSH
- ječmen (rod) genetika fyziologie MeSH
- listy rostlin metabolismus fyziologie MeSH
- nízká teplota MeSH
- rostlinné proteiny biosyntéza genetika metabolismus MeSH
- výhonky rostlin fyziologie MeSH
- zmrazování MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
