title: Does iodine biofortification affect oxidative metabolism in lettuce plants?
abstract: Plants produce low levels of reactive oxygen species (ROS), which form part of basic cell chemical communication; however, different types of stress can lead to an overexpression of ROS that can damage macromolecules essential for plant growth and development. Iodine is vital to human health, and iodine biofortification programs help improve the human intake through plant consumption. This biofortification process has been shown to influence the antioxidant capacity of lettuce plants, suggesting that the oxidative metabolism of the plant may be affected. The results of this study demonstrate that the response to oxidative stress is variable and depends on the form of iodine applied. Application of iodide (I(-)) to lettuce plants produces a reduction in superoxide dismutase (SOD) activity and an increase in catalase (CAT) and L-galactono dehydrogenase enzyme activities and in the activity of antioxidant compounds such as ascorbate (AA) and glutathione. This did not prove a very effective approach since a dose of 80 μM produced a reduction in the biomass of the plants. For its part, application of iodate (IO (3) (-) ) produced an increase in the activities of SOD, ascorbate peroxidase, and CAT, the main enzymes involved in ROS detoxification; it also increased the concentration of AA and the regenerative activities of the Halliwell-Asada cycle. These data confirm the non-phytotoxicity of IO (3) (-) since there is no lipid peroxidation or biomass reduction. According to our results, the ability of IO (3) (-) to induce the antioxidant system indicates that application of this form of iodine may be an effective strategy to improve the response of plants to different types of stress.
authors.affiliation: Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain. bblasco@ugr.es
authors.forename: Begoña
authors.initials: B
authors.lastname: Blasco
authors.forename: Juan Jose
authors.initials: JJ
authors.lastname: Ríos
authors.forename: Rocío
authors.initials: R
authors.lastname: Leyva
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Cervilla
authors.forename: Eva
authors.initials: E
authors.lastname: Sánchez-Rodríguez
authors.forename: María Mar
authors.initials: MM
authors.lastname: Rubio-Wilhelmi
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Rosales
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Ruiz
authors.forename: Luis
authors.initials: L
authors.lastname: Romero
mesh_terms: D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D007455:Iodine / Q000378:metabolism*; D018545:Lactuca / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D007455:Iodine; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid