Ren J, Liu L, Jin X L, Fu S L, Ding Z C
College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, China.
Institutes of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, China.
Genet Mol Res. 2014 Nov 12;13(4):9569-77. doi: 10.4238/2014.November.12.5.
Alpha (α)-particle radiation has been thoroughly studied in the occupational and residential environments, but biological mechanisms induced by α-particle radiation on plants are not clearly understood. In this study, radiation effects were examined using different total doses (1, 10, 100 Gy, respectively) of 241Am, α-particle on Arabidopsis embryos. No significant difference in the germination percentage was observed between the 3 levels of doses and the control. Germination speed and root length were increased by treatment with the 1-Gy dose of a-particles, and decreased by treatment with 10- and 100-Gy doses. Moreover, the bending degree of roots increased with radiation dose, and the roots showed an "S" shape when treated with the 100-Gy dose. Root bending under the 100-Gy dose was inhibited by scavengers of reactive oxygen species (ROS). Root gravitropism and root length may respond to the consistency of ROS induced by irradiation. Further analysis of the physiological effects revealed that an increase in a-particle radiation intensity enhanced the activity of catalase and the content of malondialdehyde, but superoxide dismutase activity was reduced by treatment with 100-Gy radiation of a-particles, suggesting that the high linear energy transfer of a-particles may cause a relatively high level of membrane lipid preoxidation and high accumulation of ROS. ROS showed both physiological and morphological responses following exposure to α-particle radiation in Arabidopsis embryos.
α粒子辐射在职业和居住环境中已得到充分研究，但α粒子辐射对植物诱导的生物学机制尚不清楚。在本研究中，使用不同总剂量（分别为1、10、100 Gy）的241Amα粒子对拟南芥胚胎进行辐射效应检测。在这3个剂量水平与对照之间未观察到发芽率的显著差异。用1 Gy剂量的α粒子处理可提高发芽速度和根长，而用10 Gy和100 Gy剂量处理则降低发芽速度和根长。此外，根的弯曲程度随辐射剂量增加而增加，用100 Gy剂量处理时根呈“S”形。100 Gy剂量下的根弯曲受到活性氧（ROS）清除剂的抑制。根的向地性和根长可能对辐射诱导的ROS一致性作出反应。对生理效应的进一步分析表明，α粒子辐射强度增加会提高过氧化氢酶活性和丙二醛含量，但用100 Gy的α粒子辐射处理会降低超氧化物歧化酶活性，这表明α粒子的高线性能量传递可能导致较高水平的膜脂过氧化和ROS的高积累。在拟南芥胚胎中，暴露于α粒子辐射后，ROS表现出生理和形态学反应。
