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.
J Plant Physiol. 2011 Nov 1;168(16):1960-71. doi: 10.1016/j.jplph.2011.05.008. Epub 2011 Jun 12.
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.
拟南芥可能对伽马射线的传感器很少，对其做出响应的信号转导系统也很少。为了评估它们的辐射敏感性，用各种剂量的伽马射线照射营养（VE）和生殖（RE）阶段的野生型（Ler）拟南芥植物。与未辐照相比，100Gy 处理在 VE 和 RE 阶段都诱导了更多的蒴果产生。超过 200Gy 的处理抑制了芽的生长，而 800Gy 的处理导致植物死亡。使用电子自旋共振（ESR）和透射电子显微镜（TEM）进行的生理分析的结果表明，增加剂量的伽马射线会引起更多的 ROS 产生。为了建立伽马辐射后的基因表达谱并分析抗氧化反应，我们采用了寡核苷酸微阵列系统。观察到伽马辐照后与 ROS 清除和信号转导途径相关的基因表现出不同的反应。在所有表达显著改变的基因中，至少有 33 个和 42 个与 ROS 清除和信号转导途径有关，其诱导或抑制比至少为 2 倍。CAT3（At1g20620）、Ferritin1（At5g01600）、蓝铜结合蛋白（At5g20230）和 AOX 假定（At1g32350）在 VE 阶段均上调，与剂量无关。活性氧信号转导基因编码的磷脂酶、锌指蛋白、WRKY DNA 结合蛋白和钙结合蛋白的表达量都很高，变化超过 2 倍。我们对拟南芥基因对伽马辐射反应的转录组图谱显示，植物对许多信号转导和抗氧化基因的表达发生了改变，这与其他环境胁迫一样。
