title: Antioxidant response of Arabidopsis plants to gamma irradiation: Genome-wide expression profiling of the ROS scavenging and signal transduction pathways.
abstract: Arabidopsis presumably has few sensors for gamma-rays and few signal transduction systems that respond to them. In an effort to assess their radiation sensitivity, wild-type (Ler) Arabidopsis plants were irradiated with various doses of gamma-rays at the vegetative (VE) and reproductive (RE) stages. 100Gy treatment induced the higher production of siliques during both the VE and RE stages compared with non-irradiation. Treatments at doses over 200Gy repressed shoot growth, and the plants perished under 800Gy treatment. The results of physiological analysis using electron spin resonance (ESR) and transmission electron microscopy (TEM) revealed that increased doses of gamma-rays induce greater ROS generation. To establish the gene expression profiles after gamma irradiation and for an analysis of the antioxidant response, we employed an oligonucleotide microarray system. Different responses of genes related with ROS scavenging and signal transduction pathways by a gamma irradiation were observed. At least 33 and 42 out of all genes with significantly altered expression were associated with ROS scavenging and signal transduction pathways having an induction or repression ratio cutoff of at least 2-fold, respectively. CAT3 (At1g20620), Ferritin1 (At5g01600), Blue copper binding protein (At5g20230), and AOX putative (At1g32350) were up-regulated regardless of dosage at the VE stage. Reactive oxygen species signaling genes encoding phospholipase, zinc finger protein, WRKY DNA-binding protein, and calcium binding protein were highly expressed, evidencing changes greater than 2-fold. Our transcriptomic profile of the responses of Arabidopsis genes to gamma irradiation showed that plants evidenced altered expressions of many signal transduction and antioxidant genes, as have been seen with other environmental stresses.
authors.affiliation: Division of Food Irradiation and Plant Breeding, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong, Jeongeup, Jeonbuk, 580-185, Republic of Korea. bioplant@kaeri.re.kr
authors.forename: Dong Sub
authors.initials: DS
authors.lastname: Kim
authors.forename: Jin-Baek
authors.initials: JB
authors.lastname: Kim
authors.forename: Eun Jeong
authors.initials: EJ
authors.lastname: Goh
authors.forename: Wook-Jin
authors.initials: WJ
authors.lastname: Kim
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Yong Weon
authors.initials: YW
authors.lastname: Seo
authors.forename: Cheol Seong
authors.initials: CS
authors.lastname: Jang
authors.forename: Si-Yong
authors.initials: SY
authors.lastname: Kang
mesh_terms: D000975:Antioxidants / Q000378:metabolism / Q000528:radiation effects*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000528:radiation effects*; D005720:Gamma Rays; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000528:radiation effects; D018745:Genome, Plant / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000528:radiation effects*; D013312:Stress, Physiological / Q000528:radiation effects; D059467:Transcriptome
chemical_list: D000975:Antioxidants; D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species