Physiological response of wheat seedlings to mild and severe osmotic stress
In the present study the physiological status of two wheat (Triticum aestivum L.) cultivars subjected to polyethylene glycol-induced dehydration is evaluated. Wheat seedlings were exposed to either 8-d-long mild (15% PEG) or 24-h-long severe (30% PEG) osmotic stress by immersing their roots in PEG-supplemented Knop nutrient solution. Relative water content in the leaves and the levels of free proline, malondialdehyde, and hydrogen peroxide were chosen as indicative parameters corresponding to the degree of stress of the treated plants. Electrolyte leakage from leaf tissues of control and stressed plants was compared in terms of the common parameter Injury index used for characterizing cell membrane stability. In addition, a model test system was established for preliminary stress evaluation based on the kinetics of ion leakage. Short-term exposure to higher concentration of PEG was considered to be more harmful than prolonged mild stress as judged by RWC, proline and hydrogen peroxide accumulation, and injury index. The two cultivars demonstrated more obvious dissimilarities under conditions of prolonged mild stress than under severe stress.
Keywordselectrolyte leakage hydrogen peroxide malondialdehyde osmotic stress polyethylene glycol proline wheat
- Hoekstra, F.A., Golovina, E.A. 1999. Membrane behavior during dehydration: implications for desiccation tolerance. Russ. J. Plant Physiol. 46:295–306.Google Scholar
- Király, I., Czövek, P. 2002. Changes of MDA level and O2 scavenging enzyme activities in wheat varieties as a result of PEG treatment. Acta Biol. Szeged 46:105–106.Google Scholar
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