Chilling stress was one of the most sever abiotic stress to restrict cucumber plant growth.The effects of different concentrations of spermidine( 0.1,0.5,1 and 5 mM) on photosynthetic characteristics,antioxidant( cata...Chilling stress was one of the most sever abiotic stress to restrict cucumber plant growth.The effects of different concentrations of spermidine( 0.1,0.5,1 and 5 mM) on photosynthetic characteristics,antioxidant( catalase,ascorbate peroxidase,superoxide dismutase and peroxidase) enzyme activities,malondialdehyde( MDA) content,electrolyte leakage and H_2 O_2 content of cucumber seedlings under chilling stress were studied.The results showed that chilling stress reduced photosynthetic capacity and the value of the maximal photochemical efficiency of PSII( Fv/Fm),and increased electrolyte leakage and the content of MDA and H_2 O_2.Exogenous Spd application led to a tendency of photosynthetic characteristics and antioxidant enzyme activities to first increase and then decrease with the concentration of exogenous Spd increasing.Furthermore,electrolyte leakage and the contents of MDA and H_2 O_2 significantly decreased in plants treated with Spd.Results of this study suggest that exogenous Spd can improve cucumber tolerance to chilling stress,and the optimal concentration of Spd to alleviate chilling stress in cucumber was 0.5 mM in the present study.展开更多
基金Supported by Shanghai Science and Technology Commission Project,China(18ZR1433200)National Key Technology R&D Program(2014BAD05B05-05)Shanghai Agriculture Applied Technology Development Program,China(Grant No.20170201)
文摘Chilling stress was one of the most sever abiotic stress to restrict cucumber plant growth.The effects of different concentrations of spermidine( 0.1,0.5,1 and 5 mM) on photosynthetic characteristics,antioxidant( catalase,ascorbate peroxidase,superoxide dismutase and peroxidase) enzyme activities,malondialdehyde( MDA) content,electrolyte leakage and H_2 O_2 content of cucumber seedlings under chilling stress were studied.The results showed that chilling stress reduced photosynthetic capacity and the value of the maximal photochemical efficiency of PSII( Fv/Fm),and increased electrolyte leakage and the content of MDA and H_2 O_2.Exogenous Spd application led to a tendency of photosynthetic characteristics and antioxidant enzyme activities to first increase and then decrease with the concentration of exogenous Spd increasing.Furthermore,electrolyte leakage and the contents of MDA and H_2 O_2 significantly decreased in plants treated with Spd.Results of this study suggest that exogenous Spd can improve cucumber tolerance to chilling stress,and the optimal concentration of Spd to alleviate chilling stress in cucumber was 0.5 mM in the present study.
