Pretreatment with low-dose gamma irradiation enhances tolerance to the stress of cadmium and lead in Arabidopsis thaliana seedlings.
Heavy metals are important environmental pollutants with negative impact on plant growth and development. To investigate the physiological and molecular mechanisms of heavy metal stress mitigated by low-dose gamma irradiation, the dry seeds of Arabidopsis thaliana were exposed to a Cobalt-60 gamma source at doses ranging from 25 to 150Gy before being subjected to 75µM CdCl2 or 500µM Pb(NO3)2. Then, the growth parameters, and physiological and molecular changes were determined in response to gamma irradiation. Our results showed that 50-Gy gamma irradiation gave maximal beneficial effects on the germination index and root length in response to cadmium/lead stress in Arabidopsis seedlings. The hydrogen peroxide and malondialdehyde contents in seedlings irradiated with 50-Gy gamma rays under stress were significantly lower than those of controls. The antioxidant enzyme activities and proline levels in the irradiated seedlings were significantly increased compared with the controls. Furthermore, a transcriptional expression analysis of selected genes revealed that some components of heavy metal detoxification were stimulated by low-dose gamma irradiation under cadmium/lead stress. Our results suggest that low-dose gamma irradiation alleviates heavy metal stress, probably by modulating the physiological responses and gene expression levels related to heavy metal resistance in Arabidopsis seedlings.
Henan Provincial Key Laboratory of Ion Beam Bio-engineering, Zhengzhou University, Zhengzhou 450052, China.
Wencai
W
Qi
College of Life Science, Henan Normal University, Xinxiang 453007, China.
Liang
L
Zhang
Henan Provincial Key Laboratory of Ion Beam Bio-engineering, Zhengzhou University, Zhengzhou 450052, China.
Lin
L
Wang
Henan Provincial Key Laboratory of Ion Beam Bio-engineering, Zhengzhou University, Zhengzhou 450052, China.
Hangbo
H
Xu
Institute of Crops and Utilization of Nuclear Technology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Qingsheng
Q
Jin
Henan Provincial Key Laboratory of Ion Beam Bio-engineering, Zhengzhou University, Zhengzhou 450052, China. Electronic address: jiaozhen@zzu.edu.cn.
Zhen
Z
Jiao
D017360:Arabidopsis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D002104:Cadmium / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity*; D005720:Gamma Rays; D018525:Germination / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000032:analysis; D007854:Lead / Q000633:toxicity*; D008315:Malondialdehyde / Q000032:analysis; D036226:Seedlings / Q000737:chemistry / Q000187:drug effects / Q000528:radiation effects; D013312:Stress, Physiological
D004785:Environmental Pollutants; D002104:Cadmium; D007854:Lead; D008315:Malondialdehyde; D006861:Hydrogen Peroxide
Arabidopsis thaliana; Heavy metal detoxification; Heavy metal stress; Low-dose gamma irradiation; Physiological response