Comparison of remote consequences in Taraxacum officinale seed progeny collected in radioactively or chemically contaminated areas

Abstract

We carried out a comparative study of seed progeny taken from the dandelion (Taraxacum officinale s.l.) coenopopulations exposed for a long time to radioactive or chemical contamination originated from the East-Ural radioactive trace zone (EURT) or Nizhniy Tagil metallurgical combine impact zone (NTMC), respectively. Coenopopulations from EURT, NTMC and background areas significantly differ from each other with respect to the qualitative and quantitative composition of allozyme phenes. An analysis of clonal diversity showed the uniqueness of all coenopopulations in terms of their phenogenetics. P-generation seed viability was found to decrease in a similar manner as all types of the industrial stress increased. Studies of F (1)-generation variability in radio- and metal resistance by family analysis showed that seed progeny from EURT impact zone possessed high viability that, however, was accompanied by development of latent injuries resulting in low resistance to additional man-caused impacts. In F (1)-generation originated from NTMC zone, high seed viability was combined with increased resistance to provocative heavy metal and radiation exposure. No significant differences in responses to 'habitual' and 'new' factors, i.e. pre-adaptation effect, were found in samples from the contaminated areas.

Changes in DNA Methylation in Arabidopsis thaliana Plants Exposed Over Multiple Generations to Gamma Radiation

“…Earlier flowering leads to quicker seed production and therefore secures the next generation. In some cases, seeds have been shown to be more stress resistant, however, under IR this is still controversial (Maity et al, 2009;Melki and Marouani, 2009;Moussa, 2011;Pozolotina et al, 2012). Alongside, premature flowering can also result in a reduced number and/or mass of the seeds (Huijser and Schmid, 2011).…”

“…However, with these studies it is important to keep in mind the difference between transgenerational studies, which explore the inherited effects over generations after exposure to stress in the first generation, and multigenerational studies, which explore the inherited effects over generations that are all exposed to a similar stress factor in each generation. Work on plant survival and reproduction in the Chernobyl exclusion zone, the Fukushima affected area, as well as studies done in lab conditions continue to contribute to the uncovering of a potential adaptation to IR exposure (Zaka, 2002;Geras'kin et al, 2005;Danchenko et al, 2009;Klubicova et al, 2012;Pozolotina et al, 2012;Rashydov and Hajduch, 2015;Georgieva et al, 2017;Kryvokhyzha et al, 2018). As mentioned, heritable epigenetic changes, such as DNA methylation, might play an important role in the adaptive responses to environmental stress (Schmid et al, 2018;Horemans et al, 2019).…”

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 ).…”