Time-dependent changes of the physiological status of Bromus inermis Leyss. seeds from chronic low-level radiation exposure areas

Abstract

The seed progeny of smooth brome (Bromus inermis Leyss.) were evaluated over a year for their viability, mutation rate, resistance to radiation and antioxidant status in response to chronic radiation exposure. Bromus inermis is found in the Eastern Ural Radioactive Trace (EURT) area and the background territories (surrounding territories that are used as controls as they only have natural background radiation). The absorbed doses by smooth brome from the EURT area were 1.5–18.5 times higher compared to background locations for parent plants and 1.1–11.6 times higher for the seed embryos. There are predictable and asynchronous changes in the survival of shoots and root growth rate between background populations and chronically irradiated samples. The provocative dose of 250 Gy is more damaging in the winter months, than in the summer and autumn. The frequency of anomalies in shoots varied in different months, with the biggest rate of mutation recorded in physiologically harsher period (autumn–winter). There is no correlation between resulting survival rate of shoots and their resistance to radiation. The intense activity of the antioxidant systems (estimated by the content of low molecular weight antioxidants) allowed faster growth of the shoots and reduced the number of abnormalities seen in development.

Keywords:

• Kyshtym accident
• ERICA Tool
• low-level radiation
• Bromus inermis Leyss.
• seed quality
• seasonal rhythms
• antioxidants

Acknowledgements

We gratefully thank MS Natal’ya Petrova (Ural Federal University) and Engineer Tat’yana Belyaeva (IPAE UB RAS) for technical help.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Program of the Russian Foundation on Basic Research [grant number 11-04-01260]; Federal Special Scientific and Technical Program in support of leading scientific schools [grant number SS-2840.2014.4].

Funding

This work was supported by Program of the Russian Foundation on Basic Research [grant number 11-04-01260]; Federal Special Scientific and Technical Program in support of leading scientific schools [grant number SS-2840.2014.4].