Research at the Section for Genome Biology (BIOVIT) investigates how and why different plant species respond differently to radiation exposure, revealing major differences in their ability to detect and repair damage
April 2026 marked the 40th anniversary of the Chernobyl nuclear power plant disaster. This event led to the spread of a radioactive plume across continental Europe and the broader northern hemisphere, the impact of which is still felt today.
Besides the danger to human and animal health, radioactive contamination of forest ecosystems is a major and serious consequence of such nuclear accidents. To date, according to the Norwegian Radiation and Nuclear Safety Authority, the Chernobyl accident remains the largest source of radioactive contamination on land and in freshwater. Radioactive contamination from the disaster is still present in the environment today.
Why do some plants cope better with radiation?
When exposed to radioactive contamination, different plant species demonstrate different levels of sensitivity. Some are robust and can tolerate high radiation, whereas others are more sensitive and suffer extensive damage even at lower contamination levels.
Research at NMBU is shedding light on this ‘differential radiosensitivity’. Such efforts will help to understand the mechanisms behind the different responses observed in different plant species - an important goal for assessing environmental risks in contaminated ecosystems.
In a recent study, published in the journal Plant Stress, Dr Payel Bhattacharjee, professor Jorunn E. Olsen, and colleagues compared the radiation-sensitive species Norway spruce with Arabidopsis thaliana, a well-studied radiation-tolerant plant. By exposing both plant species to identical radiation levels, they revealed molecular responses associated with differences in radiosensitivity.
Testing plant responses across radiation levels
The researchers exposed seedlings from each species to a range of gamma radiation levels for 48 hours. Starting from relatively low experimental levels (though still far above natural background), up to radiation intensities representative of contaminated environments.
As expected, Norway spruce showed reduced growth at the highest radiation intensity, as well as damage to DNA and other parts of the cells even at the lowest radiation levels
In contrast, Arabidopsis maintained normal growth across most treatments and showed much less DNA and cellular damage, only at the highest radiation levels.
At the molecular level, the researchers used an approach called transcriptomics to assess which genes were activated by different levels of radiation. The differences between the two species were striking.
Arabidopsis responded to radiation exposure by rapidly activating genes involved in DNA repair, antioxidant defense, and stress responses, even at low radiation doses. In short, the ‘call to action’ for the cellular machinery to fix damage caused by radiation happens quickly and is highly sensitive.
Norway spruce, on the other hand, was not so reactive. This species showed similar protective molecular mechanisms as Arabidopsis, but only at much higher radiation doses, and is less effective at repairing the damage
Implications for contaminated ecosystems
This work has important implications related to risk assessment and protection of plant communities in areas contaminated by radiation.
The results confirm that, under severe radiation exposure, sensitive species such as Norway spruce require special attention regarding measures to limit critical damage. Furthermore, the molecular insights from this study may support future efforts to identify plants that are better able to cope with radiation in vulnerable environments.
Such knowledge might also be used to develop plants to become more resilient under other relevant environmental radiation, for example, exposure to elevated UV‑B in some regions, which is becoming more important as climate conditions change.
The publication is available in full on the Plant Stress journal website.