Changes in Membrane permeability and Antioxidative Enzymes Activity in Response to Low Temperature in Soybean Seedlings

Soybean (Glycine max) is one of the tropical plants that is also cultivated in temperate regions. Because of the nutritional and medical importance of this crop and its sensitivity to growth medium temperature and vital role of impact biomembranes، the effect of low non-freezing temperature and plants response to it was investigated. Plants were exposed to 15C (cold-acclimated) or 25C (nonacclimated) for 24h، under 250 μmol m-2s-1 photo synthetically active radiations (PAR). Then all plants were exposed to 4C (chilling temperature) for 24h and allowed to recover at 25C for 24h. We analyzed the activity of ascorbate peroxidase (APX) and guaiacol peroxidase (GPX)، electrolyte leakage in leaves and roots. Chilling sensitive soybean plants can be made tolerant to cold by cold acclimation via exposing the plants to nonfreezing low temperatures.