Physiological responses of Krascheninnikovia ewersmannia under drought stress

The physiological responses of Krascheninnikovia ewersmannia to drought stress was studied using 0 (CK), 5%, 15%, 25%, 30%, and 35% polyethylene glycol (PEG-6000) to simulate drought stress from the aspects of osmotic regulation substances, protective substances, and fatty acid components. The results showed that under the 5%, 15% low concentration of PEG treatment, the damage of membrane lipid peroxidation to the cellular membrane system was weakened through increasing the content of osmotic adjustment substance proline, initiating the antioxidant enzyme system, and maintaining the dynamic balance of saturated fatty acids and unsaturated fatty acids in membrane lipids; under the treatment of 25% PEG, the content of malondialdehyde increased sharply and the degree of membrane lipid peroxidation was aggravated. Plants can reduce membrane lipid damage caused by drought stress by significantly increasing the proline content, enhancing antioxidant enzyme activity, and increasing unsaturated fatty acid content in membrane lipid; under the 30%, 35% high concentration PEG treatment, proline content decreased, antioxidant enzyme system activity decreased, saturated fatty acid content increased, and membrane lipids were seriously damaged. It is concluded that with the 25% PEG treatment solution, osmoregulatory substances, protective substances, unsaturated fatty acids, and other substances act together to form an efficient defense system to enhance the resistance to drought stress.