The Effect Of Zinc On Wheat Seedings Under Salt Stress And Molecular Mechanism

Salt stress reduced plants for zinc and other mineral absorption and caused plantsnutrition disorders.Zinc is an essential micronutrient for all living organisms nutrientsand involved in the metabolic activity of life in plants closely. The status of Zinc inmaintaining salt tolerance in plants is crucial, however,researchs in this area aboutzinc’s function on salt tolerance in plants are little.Therefore,strengthening theresearch of zinc on the physiological and molecular mechanisms of wheat seedlingsunder salt stress,that can reveal resilience mechanisms of crops and has an importantguiding significance in crop production on saline region.We chose a zn-accumulating winter wheat cultivar,Jingdong8,which has beencultivated in the Hebei province of China for over ten years,and we chose the winterwheat cultivar Shi4185as a control for the study, Studied the effects on wheatseedling growth and physiological and molecular mechanisms under salt stress andsalt stress with zinc conditions, in order to investigate the function of zinc on salttolerance in plants, providing theoretical basis and reference for screening the cultivarof salt tolerance and has a high ability to accumulate zinc for agricultural productionand breeding.Test used the indoor hydroponic methods,50mM NaCl was used to simulate saltstress,1uM of Zn added50mM NaCl was used to simulate the interactive simulationof zinc and salt stress.Hydroponics experiment solutions were1/2Hogland nutrientsolution preparation,Plant height,root length,MDA,soluble sugar,Na+concentration,antioxidant enzymes content such as SOD,APX,POD were measuredafter duress,and do a PI, DAPI,ROS, DAB and NBT staining,the expression ofTaSOS1and TaNHX1were measured with fluorescence quantitative methods.The main results are as follows:1、Wheat seedlings treated with50mM salt after20days,the relative root lengthand height of shi4185and Jingdong8decreased compared to the control, zincsupplementation after salt treatment,the relative root length and plant height of thetwo cultivars increased compared to treatment of salt alone.50mM salt treatmentsignificantly inhibited the growth of wheat seedlings,zinc can ease growth injurycaused by salt stress on wheat seedling. 2、 Salt stress affects most of the activities of antioxidant enzymes,.zincsupplementation after salt treatment,SOD activity in the leaves of shi4185andJingdong8significantly increased compared to the treatment of salt alone.APXactivity in the leaves of of the two cultivars decreased compared to the treatment ofsalt alone,APX activity in the roots of of the two cultivars increased compared to thetreatment of salt alone;zinc supplementation after salt treatment,POD activity inleaves and roots of of the two cultivars both decreased compared to the treatment ofsalt alone.3、zinc supplementation alleviates oxidative damage to cell membranes.zincsupplementation after salt treatment.Compared with shi4185,accumulation of reactiveoxygen species in vivo under zinc supplementation after salt treatment is much lowerin Jingdong8,thereby protecting the integrity of cell membranes and reduces the apicalcell death.It means zinc loweres the level of H2O2and O2-,zinc increases the activityof antioxidant enzymes.Besides zinc supplementation reduces the programmed celldeath in the tip cells of wheat root effectively induced by salt.4、Na+content was significantly reduced in leaves and roots of the two wheatvarieties in the zinc supplementation after salt treatment,and Na+content is lower inroots and leaves of Jingdong8than shi4185.5、Ten days after the treatment,the expression of TaSOS1and TaNHX1furtherincreased in the roots after zinc supplemented.The increased expression of TaSOS1can increase the efflux of Na+in plants,and the increased expression of TaNHX1canstrand Na+in the vacuole root cells,thereby reducing Na+transport from root to stem.