Effects of Exogenous Selenium on Physiological Characteristics of Wheat Seedlings Under Low Temperature Stress
[Objective]The effects of exogenous selenium(Se)on the physiological characteristics of wheat seedlings under low temperature stress were explored,which provided references for enhancing cold resistance and ensuring safe production of wheat.[Method]Taking Jimai 22 as the experimental material,the effects of different concentrations of Na2SeO3(CK,0µmol/L Na2SeO3;T1,2µmol/L Na2SeO3;T2,4µmol/L Na2SeO3;T3,6µmol/L Na2SeO3)on the photosynthetic characteristics,antioxidant enzyme activities and osmotic regulation substance content in wheat seedling leaves were studied.[Result]Under low temperature stress,leaf Pn,Gs,Tr,Fv/Fm and ETR of all Na2SeO3 treatments significantly increased,while Ci significantly reduced.The contents of chlorophyll a,chlorophyll b,carotenoids,total chlorophyll,as well as the activities of SOD,POD,CAT and APX increased significantly.GSH and AsA content increased,and MDA content significantly reduced.Moreover,free amino acids,free proline,soluble sugar and soluble protein contents notably increased.Specifically,compared to CK,6µmol/L Na2SeO3 treatment resulted in the highest Pn[(7.47 µmol/(m2·s)],Gs[(0.104 mol/(m2·s)],Tr[(0.0020 µmol/(m2·s)],Fv/Fm(0.605)and ETR[(41.74 µmol/(m2·s)],with the lowest Ci[(233.212µmol/(m2·s)].Chlorophyll a(4.30 mg/g FW),chlorophyll b(2.27 mg/g FW),carotenoids(0.64 mg/g FW)and total chlorophyll content(6.57 mg/g FW)were also the highest,alongside maximum activities of SOD[75.76 U/(g·min)FW],POD[48.53 μmol/(g·min)FW],CAT[(23.77 μmol/(g·min)FW]and APX[8.64 U/(mg·min)FW].GSH(81.47 μmol/g FW)and AsA(1 521.3 mg/100g FW)levels were the highest,while MDA content was the lowest(6.54 μmol/g FW).Free amino acids(684.44 µg/g FW),free proline(726.97 µg/g FW),soluble sugar(41.26%)and soluble protein(8 873.57µg/g FW)contents reached their peaks.[Conclusion]The addition of 6µmol/L Na2SeO3 effectively increases chlorophyll content in wheat seedlings,improves photosynthesis and strengthens the antioxidant system,thereby enhancing cold resistance and growth performance.
seleniumwheatlow temperature stressphotosynthetic parametersantioxidant enzyme activityosmotic regulators accumulationphysiological characteristics
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维普
