The toxicity of engineered nanoparticles on seed plants chronically exposed to low-level environmental radiation

Abstract

Nothing is known about how plant populations chronically exposed to radiation adapt to a new anthropogenic stressor as engineered nanoparticles (ENP). A set of ecotoxicity tests was conducted with five types of ENP to investigate seed response of Leonurus quinquelobatus populations growing naturally under low dose irradiation and background conditions. Five day toxicity tests detect the combined stimulation pos itive effects of irradiation stress with two types of ENP on seed germination. All of these effects are smoothed in 21 day old seedlings or reveal the significant adverse effects in three of the ENP. The commonly increased mutation load at the radiation pollution area synergistically increases fourfold to eightfold after TiO 2 nano particle suspension exposure at 0.5-10 mM. These findings highlight the response on the combined nano particle and ionizing radiation influence on plant systems in the wild indicating that the environmental risk assessment of 4 of 5 ENP needs to be carried out.

Ionizing Radiation, Higher Plants, and Radioprotection: From Acute High Doses to Chronic Low Doses

“…In long-term studies of P. sylvestris in the Chernobyl-contaminated Bryansk Oblast of Russia, germinating seeds have rates of cytogenetic damage of up to 1.3% that correlate with dose rate ( Geras’kin et al, 2011 ), and that is repeated elsewhere at even lower dose rates ( Evseeva et al, 2011 ). Several detailed studies of plants growing in the East Urals Radioactive Trace, which has the longest history (1957 onwards) of any widely studied radioactively contaminated site and has dose rates of up to 240 mGy/y ( c. 28 μGy/h), have shown dose-dependent effects on germination or viability of seeds of Taraxacum officinale ( Pozolotina et al, 2012 ), Melandrium album ( Antonova et al, 2013 ), and Leonurus quinquelobatus ( Karimullina et al, 2015 ). Several authors have noted that chronic low dose rates of IR can make germination more variable, particularly in response to weather conditions ( Antonova et al, 2013 ; Geras’kin et al, 2016 ) and other soil contaminants ( Evseeva et al, 2009 ; Karimullina et al, 2015 ).…”

“…Several detailed studies of plants growing in the East Urals Radioactive Trace, which has the longest history (1957 onwards) of any widely studied radioactively contaminated site and has dose rates of up to 240 mGy/y ( c. 28 μGy/h), have shown dose-dependent effects on germination or viability of seeds of Taraxacum officinale ( Pozolotina et al, 2012 ), Melandrium album ( Antonova et al, 2013 ), and Leonurus quinquelobatus ( Karimullina et al, 2015 ). Several authors have noted that chronic low dose rates of IR can make germination more variable, particularly in response to weather conditions ( Antonova et al, 2013 ; Geras’kin et al, 2016 ) and other soil contaminants ( Evseeva et al, 2009 ; Karimullina et al, 2015 ). There is, however, evidence from studies in Bryansk, Russia, that such effects do not alter the overall reproductive capacity of P. sylvestris ( Geras’kin et al, 2016 ).…”

Germination and Growth Characteristics of nud Knockout and win1 Knockout Barley Lines under Salt Stress

“…The laboratory seed germination method is widely used to assess the impact of individual environmental factors (e.g., low or high temperatures, salinity, moisture deficiency, ionizing radiation, heavy metals, nanoparticles, or magnetic fields) or their combined effects by means of biometric parameters (e.g., seed germination energy, seed vigor, seedling survival, and root and shoot lengths) at early stages of plant development [18][19][20][21][22][23][24][25][26]. In several studies, the roll culture method has been applied [19,20,25,27] or Petri dishes have been used [18,[21][22][23]28]. In these cases, experiments are conducted in distilled water, aqueous solutions, soil extracts, and suspensions with the adverse factors.…”