title: The effects of chronic radiation of gamma ray on protein expression and oxidative stress in Brachypodium distachyon.
abstract: OBJECTIVE
  To compare the effects of gamma-irradiation on biochemical responses and growth, six-week-old Brachypodium plants were chronically exposed to gamma-irradiation for 30 days at various dosages.
  
  
  METHODS
  Growth surveys of Brachypodium plants in response to different dosages of gamma-irradiation were conducted to compare physiological changes between irradiated and non-irradiated plants. Photosynthetic pigments, soluble sugar content, activities of antioxidant enzymes, and malonaldehyde (MDA) induced by reactive oxygen species (ROS) production were also measured.
  
  
  RESULTS
  Gamma-irradiation had a negative influence on the average plant height, leaf length, leaf width, and fresh weight. Photosynthetic pigment levels decreased with increasing dosages of gamma-irradiation, while soluble sugar content slightly increased. Gamma-irradiation responsive proteins were detected and identified by two-dimensional gel electrophoresis (2D-PAGE) and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF). The proteins had a role in photosynthetic carbon fixation, anabolic pathway glycolysis, mitochondrial ATP production, and oxidative stress response regulation. MDA levels and activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and peroxidase (POD) increased with the increase in gamma-irradiation dosage level.
  
  
  CONCLUSIONS
  This study provides some basic information regarding responses to gamma-irradiation, and provides valuable physiological and biological data on the effects of different gamma-irradiation dosages on Triticeae species.
authors.affiliation: Division of Biotechnology, Korea University , Seongbuk-Gu, Seoul , Republic of Korea.
authors.forename: Dae Yeon
authors.initials: DY
authors.lastname: Kim
authors.forename: Min Jeong
authors.initials: MJ
authors.lastname: Hong
authors.forename: Cheong-Sool
authors.initials: CS
authors.lastname: Park
authors.forename: Yong Weon
authors.initials: YW
authors.lastname: Seo
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D058431:Brachypodium / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects*; D050260:Carbohydrate Metabolism / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000009:adverse effects*; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D015227:Lipid Peroxidation / Q000528:radiation effects; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000528:radiation effects*; D010788:Photosynthesis / Q000528:radiation effects; D010860:Pigments, Biological / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012995:Solubility; D013997:Time Factors
chemical_list: D000975:Antioxidants; D010860:Pigments, Biological; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D008315:Malondialdehyde
keywords: 2-D PAGE; Brachypodium; gamma-irradiation; reactive oxygen species