Abstract:In order to investigate the effect of aluminum (Al) stress on the ascorbateglutathione(AsAGSH) cycle in leaves of Cunninghamia lanceolata, and elucidate the role of antioxidant enzymes and AsAGSH cycle in C. lanceolata under Al stress, we employed two C. lanceolata families differing in Al tolerance (Alsensitive YX5 and Altolerant YX26), and analyzed the effect of Al stress on malondialdehyde (MDA) content, antioxidant enzyme activities, and AsAGSH cycle in leaves of C. lanceolata. The results showed that:(1) The MDA content in leaves of C. lanceolata increased significantly under Al stress as compared with the control, and the increased rate of MDA content in the leaves of C. lanceolata was lesser in the YX26 than that in the YX5.(2)The enzyme activities of peroxidase (POD), ascorbate peroxidase (APX), monodehydro ascorbate reductase (MDAR) and the contents of ascorbic acid (AsA), dehydroascorbic acid (DHA), glutathione (GSH), and oxidized glutathione (GSSG) were increased to varying degrees under Al stress, and the increased rate of enzyme activities and nonenzyme antioxidants in the leaves of C. lanceolata were higher in the YX26 than that in the YX5 except for AsA content. (3)The enzyme activities of catalase (CAT) and dehydroascorbate reductase (DHAR) were greatly inhibited in the YX5 under Al stress, while the opposite was true for the YX26. Moreover, the DHAR activity in YX26 was significantly higher under Al stress as compared with the control. Additionally, the superoxide dismutase (SOD) was suppressed in leaves of different C. lanceolata families under Al stress, and the decreased rate of SOD in YX26 was lower than that in YX5. (4) The avoved results suggested that the Altolerant C. lanceolata family can enhance the scavenged capacity for reactive oxygen species by efficiency maintaining the enzyme activities and nonenzymes antioxidants in AsAGSH cycle, and which may be the physilogical basis of resistant families in adaptation to Al stress.