title: Effect of exogenous abscisic acid on the level of antioxidants in Atractylodes macrocephala Koidz under lead stress.
abstract: This study hypothesized that the positive or negative effects of exogenous abscisic acid (ABA) on oxidative stress caused by lead were dose dependent. The effects of different levels of ABA (2.5, 5, and 10 mg L(-1)) on lead toxicity in the leaves of Atractylodes macrocephala were studied by investigating plant growth, soluble sugars, proteins, lipid peroxidation, and antioxidative enzymes. Excess Pb inhibited root dry weight, root length, and the number of lateral roots, but increased shoot growth. In addition, lead stress significantly decreased the levels of chlorophyll pigments, protein, and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD). Different levels of ABA significantly increased SOD, CAT, POD, and APX activities, but decreased the level of hydrogen peroxide and malondialdehyde in nonstressed plants. Exogenous application of 2.5 mg L(-1) ABA detoxified the stress-generated damages caused by Pb and also enhanced plant growth, soluble sugars, proteins, and all four antioxidant enzyme activities but reduced Pb uptake of lead-stressed plant compared to lead treatment alone. However, the toxic effects of Pb were further increased by the applications of 5 and 10 mg L(-1) ABA. The levels of antioxidants caused by a low concentration of exogenous ABA might be responsible for minimizing the Pb-induced toxicity in A. macrocephala.
authors: MOE Laboratory of Plant-Soil Interaction and College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China. jinchuangwang@yahoo.com
authors: Jinchuang
authors: J
authors: Wang
authors: Juan
authors: J
authors: Chen
authors: Kaiwen
authors: K
authors: Pan
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D000975:Antioxidants / Q000032:analysis*; D060387:Ascorbate Peroxidases / Q000187:drug effects / Q000378:metabolism; D031174:Atractylodes / Q000737:chemistry / Q000187:drug effects*; D002374:Catalase / Q000187:drug effects / Q000378:metabolism; D002734:Chlorophyll / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D007854:Lead / Q000633:toxicity*; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000032:analysis; D018384:Oxidative Stress / Q000187:drug effects; D009195:Peroxidase / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects; D018520:Plant Shoots / Q000737:chemistry / Q000187:drug effects; D012989:Soil Pollutants / Q000633:toxicity; D013482:Superoxide Dismutase / Q000187:drug effects / Q000378:metabolism
chemical_list: D000975:Antioxidants; D012989:Soil Pollutants; D002734:Chlorophyll; D007854:Lead; D008315:Malondialdehyde; D000040:Abscisic Acid; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase