Abstract:The photosynthetic pigment,lipid peroxidation and anti-oxidation enzymes in the leaf of Pleioblastus kongosanensis were analyzed under the stress of elevated concentration of CO2 (700 μmol·mol-1) and O3 (100 nmol·mol-1) in open-top chambers (OTCs).After samples treated for 103 days and compared to the control,the results showed that:(1)In the elevated O3 treatment groups,the contents of Chl a,Chl b,total Chl and the ratio of Chl a/Chl b,Chl/Car,the activities of SOD,POD and CAT were decreased significantly,while the contents of O-·2,MDA,Car,relative electrical conductivity and activity of APX were increased significantly;(2)In the elevated CO2 treatment groups,the contents of Chl a,Chl b,total Chl and the ratio of Chl/Car were increased significantly,and the ratio of Chl a/Chl b,contents of O-·2 and MDA,activities of SOD,POD,CAT,APX were decreased significantly and relative electrical conductivity,content of Car had no significant difference;(3)In the elevated O2 and CO2 combined treatments,except Chl/Car ratio and CAT activity were decreased significantly,other physiological indicators had no significant differences.The results showed that the activities of anti-oxidation were significantly decreased,at the same time the O3 and malondialdehyde contents were increased significantly by elevated O3,so that the cell membrane structure was damaged seriously which represents injured effects to P.kongosanensis.Reactive oxygen species were decreased significantly by elevated CO2,which presents protective efficacy on P.kongosanensis.In combined stresses of elevated CO2 and O3,the leaves of P.kongosanensis could maintain high levels of photosynthetic pigment content and antioxidant activities to effectively regulate reactive oxygen species generation and clearing balance,indicating that elevated CO2 could ameliorate the oxidative stress in certain degree.