Effects Of Calcium And Calcium Effectors On Physiological And Biochemical Characteristics Of Jujube Seedlings Under NaCl Stress

【Object】Ca²⁺Is One of A Large Number of Elements Required for Normal Growth and Development of Plants,and Also Plays An Important Role in Plant Stress Signal Transduction As A Second Messenger.As A Common Rootstock for Grafting Jujube Trees,Sour Jujube Has Excellent Characteristics Such As Resistance to Salt and Alkali,Drought,and Barrenness,and Has Certain Nutritional Value and Economic Value.in This Experiment,the Effects of Calcium and Calcium Effector Treatment on the Antioxidant System,Osmolyte Content and Nitrogen Metabolism of Sour Jujube Seedlings Under Na Cl Stress Were Explored.the Possible Ways of Exogenous Calcium to Relieve Na Cl Stress in Sour Jujube Seedlings Were Explored.the Mechanism of Salt Stress on Sour Jujube Seedlings Provides Evidence.【Methods】This Study Used Hydroponic Sour Jujube Seedlings As Test Materials to Study the Effects of Exogenous Calcium and Different Calcium Effectors on the Root and Leaves of Sour Jujube Seedlings Under150Mmol·L^-1Na Cl Stress.Cell Membrane Lipid Peroxidation Indicators,Plasma Membrane Permeability,Malondialdehyde Content,Superoxide Dismutase（Sod）,Catalase（Cat）,Peroxidase（Pod）Activities in Plant Antioxidant Systems,Changes in Soluble Sugar Content,Soluble Protein,and Proline Content of Osmotic Adjustment Substances.Observation of Nitrate Nitrogen（No₃-N）,Nitrate Reductase（Nr）,Glutamine Synthetase（Gs）,Glutamate Synthase（Gogat）and Free Amino Acid Contents.【Results】1、Compared with Na Treatment,the Plasma Membrane Permeability and Mda Content of Sour Jujube Seedlings Were Significantly Reduced After the Addition of Exogenous Ca²⁺.Superoxide Dismutase（Sod）,Catalase（Cat）,Peroxidase（Pod）Activity Was Enhanced,and Soluble Sugar,Soluble Protein,and Proline Content Were Increased.Compared with Na+Ca Treatment,the Calcium Effector Treatment Significantly Increased the Plasma Membrane Permeability and Mda Content in the Roots and Leaves of Sour Jujube Seedlings.Except for Na+Egta Treatment,the6Th Pod Activity and Soluble Protein Content Increased Significantly.Antioxidant Enzyme Activity,Soluble Protein and Soluble Sugar Contents in Leaves and Leaf All Decreased Significantly.There Were Differences in the Regulation of Proline by the Three Calcium Effectors and Specificity Among Different Tissues.2、Compared with Na Treatment,the Activities of Nr,Gs and Gogat Were Enhanced,and the Content of Nitrate Nitrogen and Free Amino Acid Increased After the Addition of Exogenous Ca²⁺.Compared with the Na+Ca Treatment,the Calcium Effector Treatment Significantly Increased the Nr,Gs,and Gogat Activities in the Roots and Leaves of Sour Jujube Seedlings,the Content of Free Amino Acids Increased Significantly,and the Content of Nitrate Nitrogen Decreased Significantly.【Conclusion】the Addition of Exogenous Ca²⁺Under Na C1Stress Could Reduce the Degree of Membrane Lipid Peroxidation,Increased the Protective Enzyme Nitrogen Metabolism Enzyme Activity,Enhanced the Osmotic Adjustment Ability and Ammonia Assimilation Ability,and Alleviated the Damage of Na Cl Stress on Sour Jujube Seedlings.the Results of This Study Indicated That the Calcium Messenger System May Through Regulating the Activity of Antioxidant Enzymes,Osmolyte Content and Nitrogen Metabolism of Sour Jujube Seedlings Are Involved in Stress Signal Transmission of Sour Jujube Seedlings Under Na Cl Stress.