Chernobyl plant life endures radioactivity

The city of Pripyat has been abandoned and dubbed a "dead city"

Scientists have uncovered mechanisms that allow plants to thrive in highly radioactive environments like Chernobyl.

They analysed seeds from soybean and flax grown near the site of the Chernobyl nuclear reactor which exploded in 1986.

The team says that plants may have an innate ability to cope with radioactivity.

The study appears in the Environmental Science and Technology journal.

One of the researchers speculates that such mechanisms could trace back millions of years, when early life forms were exposed to higher levels of natural radiation.

'Worst' accident

If a disaster strikes, plants cannot move to better conditions - they either adapt, or die.

When, on 26 April, 1986, one of the reactors at the Chernobyl nuclear power plant exploded, the accident was said to be the worst nuclear disaster in human history.

Scores of people died, hundreds became ill with acute radiation sickness.

The entire population of the industrial city of Pripyat that housed the power plant's workforce was evacuated.

Many believed that the area would remain lifeless for generations.

Almost a quarter of a century later, Pripyat remains a ghost town. But despite deserted streets, the soil is not bare - plants have sprung back to life.

Plants 'thriving'

The way Pripyat's ecosystem seemed to shrug off the contamination caught the attention of the scientific world and in 2005, the UN even published a report about the phenomenon.

Then, in 2007, a group of researchers wearing masks, goggles and gloves decided to investigate just how the plants were able to survive.

Soybean plant appears to thrive in contaminated soil

They went into the restricted area and planted soybean and flax seeds on a highly contaminated field just a few kilometres from the site of the accident, in the environs of Pripyat.

Then they sowed the same kind of seeds on a control field in the decontaminated region near the city of Chernobyl.

One of the researchers, Martin Hajduch from the Slovak Academy of Sciences, told BBC News that even though previous studies had analysed how genes mutated because of radioactivity, his team wanted to do something different.

They wanted to investigate the molecular mechanisms allowing plants to adapt to such a contaminated environment.

To do that, they waited for the plants to grow and produce new seeds and then examined their proteins.

"We decided to apply a... methodology called 'proteomics' that is capable of identifying hundreds of proteins," said Dr Hajduch.

He explained that proteomics was a study of proteins - vital parts of all living organisms. The word "proteome" is actually a blend of "protein" and "genome" and describes the entire complement of proteins produced by an organism's genes.

"Proteins are fingerprints of metabolic activities. And as we're comparing the proteins from seeds harvested from these two fields, we're seeing the same ones in both kinds of seeds."

Historic reasons

He said that even though both soybean and flax adapted equally well to the contaminated environment, they did it in slightly different ways.

"In soybean, we detected the mobilisation of seed storage proteins and processes similar to what we see when plants adapt [to high levels of] heavy metals," he explained.

"In flax it was different. We saw more proteins involved in cell signaling, for instance."

Scientists had to wear masks, goggles and gloves to work in the area

The scientist noted that there were probably historic reasons why it was a lot easier for plants to get used to living in increased levels of radiation.

"It is just unbelievable how quickly this ecosystem has been able to adapt," he said.

"[There must be] some kind of mechanism that plants already have inside them. Radioactivity has always been present here on Earth, from the very early stages of our planet's formation.

"There was a lot more radioactivity on the surface back then than there is now, so probably when life was evolving, these plants came across radioactivity and they probably developed some mechanism that is now in them."