title: Analysis of antioxidant enzyme activity during germination of alfalfa under salt and drought stresses.
abstract: To understand the adaptability of alfalfa (Medicago sativa L.) to environmental stresses, we analyzed the activity of several antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT), in alfalfa shoots and roots subjected to salt and drought stresses during germination. The germination rate of six alfalfa cultivars was comparatively studied under 200 mM NaCl or 35% PEG treatment. Alfalfa Xinmu No. 1 and Northstar varieties were selected as stress-tolerant and -sensitive cultivars, respectively, and were used for further characterization. After NaCl or PEG treatment, Xinmu No. 1 showed enhanced seedling growth, compared with Northstar. Xinmu No. 1 also exhibited low levels of hydrogen peroxide (H(2)O(2)) production and lipid peroxidation, compared with Northstar. In addition, Xinmu No. 1 showed higher enzymatic activity of SOD, APX, CAT, and POD in its shoots and roots than Northstar. These results seem to indicate that Xinmu No. 1 cultivar's tolerance to salt or drought stresses during germination is associated with enhanced activity of antioxidant enzymes. This study highlights the importance of antioxidant enzymes in the establishment of alfalfa seedlings under drought and salinity conditions typical of desertification.
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Xinong Road No. 26, Yangling, Shaanxi 712100, P R China.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Wang
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Haeng-Soon
authors.initials: HS
authors.lastname: Lee
authors.forename: Ki-Yong
authors.initials: KY
authors.lastname: Kim
authors.forename: Xi-Ping
authors.initials: XP
authors.lastname: Deng
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak