title: Molecular dissection of the response of the rice Systemic Acquired Resistance Deficient 1 (SARD1) gene to different types of ionizing radiation.
abstract: Exposure to ionizing radiation induces plant defenses by regulating the expression of response genes. The systemic acquired resistance deficient 1 (SARD1) is a key gene in plant defense response. In this study, the function of Oryza sativa SARD1 (OsSARD1) was investigated after exposure of seeds/plants to ionizing radiation, jasmonic acid (JA) or salicylic acid (SA).
  
  
  
  Rice seeds exposed to two types of ionizing radiations (gamma ray [GR] and ion beam [IB]) were analyzed by quantitative reverse transcription PCR (qRT-PCR) to identify the genes that are altered in response to ionizing radiation. Then, OsSARD1-overexpressing homozygous Arabidopsis plants were generated to assess the effects of OsSARD1 in the response to irradiation. The phenotypes of these transgenic plants, as well as control plants, were monitored after GR irradiation at doses of 200 and 300 Gray (Gy).
  
  
  
  The OsSARD1 transcript was strongly downregulated after exposure to GR and IB irradiation. Previous phylogenetic analysis showed that the Arabidopsis SARD1 (AtSARD1) protein is closely related to Arabidopsis calmodulin-binding protein 60g (AtCBP60g), which is known to be required for activation of SA biosynthesis. In this study, phylogenetic analysis showed that OsSARD1 was grouped with AtSARD1. The OsSARD1 gene was induced after exposure to SA and JA. The biological phenotype of OsSARD1-overexpressing Arabidopsis plants was examined. OsSARD1-overexpressing plants displayed resistance to GR; in comparison with wild-type plants, the height and weight of OsSARD1-overexpressing plants were significantly greater after GR irradiation. In addition, OsSARD1 protein was abundantly accumulated in the nucleus.
  
  
  
  The results indicate that OsSARD1 plays an important role in the regulation of the defense responses to GR and IB irradiation and exhibits phytohormone induced expression.
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.
authors.forename: In Jung
authors.initials: IJ
authors.lastname: Jung
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.|b Division of Ecological Conservation, Bureau of Ecological Research , National Institute of Ecology , Seocheon , Republic of Korea.
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Hwang
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Han
authors.affiliation: c NJBiopia Co. Ltd , Gwangju , Republic of Korea.
authors.forename: Dong Sub
authors.initials: DS
authors.lastname: Kim
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.
authors.forename: Joon-Woo
authors.initials: JW
authors.lastname: Ahn
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.
authors.forename: Hong-Il
authors.initials: HI
authors.lastname: Choi
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.
authors.forename: Soon-Jae
authors.initials: SJ
authors.lastname: Kwon
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.
authors.forename: Si-Yong
authors.initials: SY
authors.lastname: Kang
authors.affiliation: a Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute , Jeongeup , Jeollabuk , Republic of Korea.
authors.forename: Jin-Baek
authors.initials: JB
authors.lastname: Kim
mesh_terms: D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D003674:Defense Mechanisms; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D020450:Heavy Ions; D012275:Oryza / Q000378:metabolism* / Q000528:radiation effects*; D010940:Plant Proteins / Q000378:metabolism*; D011829:Radiation Dosage; D011839:Radiation, Ionizing; D013312:Stress, Physiological / Q000502:physiology* / Q000528:radiation effects*
chemical_list: D002148:Calmodulin-Binding Proteins; D010940:Plant Proteins
keywords: Gamma ray; ion beam; rice Systemic Acquired Resistance Deficient 1; stress response protein