About This Project

Unlike animals, trees produce heritable mutations throughout their life. Therefore, trees exposed to nuclear radiation provide unique tools to compare the rate of mutation before and after the accident. We hypothesize that trees exposed to nuclear radiation exhibit a higher DNA mutation rate. An international team will conduct extensive studies of tissues collected from chronically irradiated trees.

Ask the Scientists

What is the context of this research?

The Chernobyl disaster is considered the most disastrous nuclear power park accident in all of history. Before the disaster, the region around Chernobyl was predominantly a rural woodland and marshland. In 1986, Chernobyl nuclear reactor #4 exploded, spreading vast amounts of radioactive isotopes and leading to the evacuation of the population. Without humans, forests have continued to expand. Chernobyl forests remain a main source of concerns, particularly regarding the risk of a release of radioactive elements in the event of a large scale forest fire. However, Chernobyl trees constitute a valuable resource for scientists to study the consequences of long-term exposure to radiation.

What is the significance of this project?

This study is expected to generate unique genomic data to study the dynamics of the accumulation of somatic mutations in organisms. Studying this process in trees is even more important, since in plants (unlike animals) acquired somatic mutations can be transmitted to the next generation. Our main objective is therefore to quantify somatic mutations along branches initiated at different time points, in order to quantify the effects of radioactivity on mutation rates. By sampling different branches from trees at increasing distances from the reactor, we will also explore the spatial variation in mutation rates. We will conduct extensive field work to collect cores and fresh leaves from old oak and birch trees in order to track mutations in relation to past and ongoing radiation levels.

What are the goals of the project?

The goal of the project is to collect the wood core and leaf samples from oak and birch trees at different distances from the Chernobyl nuclear reactor #4 explosion. We will travel to the Chernobyl exclusion zone in October 2018 to collect cores for dating candidate trees, and return in Spring 2019 to collect fresh leaves from the trees. The tree rings on the wood cores are used to date the initiation of each branch. After the sample collection is complete, we plan to sequence the DNA from different leaves to identify the number of mutations at each internode. This proposal covers all expenses required for successful sample collection.