title: The effects of chronic gamma irradiation on oxidative stress response and the expression of anthocyanin biosynthesis-related genes in wheat (Triticum aestivum).
abstract: OBJECTIVE
  To investigate the mechanisms of adaptation and tolerance to ionizing radiation using chronic radiation in wheat.
  
  
  METHODS
  We exposed wheat plants to chronic gamma irradiation (50 Gy) for 2, 4, and 6 weeks and measured various biological parameters.
  
  
  RESULTS
  Plant height was reduced by exposure to gamma irradiation; this effect increased with increasing exposure time. Photosynthetic pigment levels decreased with increasing exposure time, while anthocyanin levels significantly increased after exposure to gamma rays. The activities of antioxidant enzymes (superoxide dismutase [SOD], ascorbate peroxidase [APX], catalase [CAT], and peroxidase [POD]) and malondialdehyde (MDA) levels increased with increasing duration of exposure to gamma irradiation. Electron spin resonance (ESR) signals were strongly detected in wheat that was gamma-irradiated for two weeks and then gradually decreased with increasing exposure time. The expression of anthocyanin biosynthesis genes (flavanone 3-hydroxylase [F3H], dihydroflavonol reductase [DFR], anthocyanin reductase [ANS], and UDPG-flavonoid glucosyl transferase [UFGT]) and sugar contents increased after exposure to gamma rays.
  
  
  CONCLUSIONS
  This suggests that exposure to ionizing radiation according to increase of exposure time has led to efficient induction of anthocyanin and antioxidant enzyme activities. This study indicates that reactive oxygen species (ROS) is eliminated by biosynthesis of anthocyanin and antioxidant enzymes. This study helps elucidate the biological effects of various durations of low-dose exposure to chronic gamma radiation in wheat plants.
authors.affiliation: Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Geumgu, Jeongeup, Jeonbuk , Republic of Korea.
authors.forename: Min Jeong
authors.initials: MJ
authors.lastname: Hong
authors.forename: Jin-Baek
authors.initials: JB
authors.lastname: Kim
authors.forename: Young Ha
authors.initials: YH
authors.lastname: Yoon
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Joon-Woo
authors.initials: JW
authors.lastname: Ahn
authors.forename: Il Yun
authors.initials: IY
authors.lastname: Jeong
authors.forename: Si-Yong
authors.initials: SY
authors.lastname: Kang
authors.forename: Yong Weon
authors.initials: YW
authors.lastname: Seo
authors.forename: Dong Sub
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000872:Anthocyanins / Q000096:biosynthesis* / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism; D001713:Biphenyl Compounds / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000528:radiation effects*; D010851:Picrates / Q000378:metabolism; D013997:Time Factors; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects*
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D002734:Chlorophyll; D002338:Carotenoids; D008315:Malondialdehyde; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: ESR; Wheat; anthocyanin; antioxidant; chronic gamma radiation