Plants that adapt to contaminated soil

In April 1986, a nuclear reactor at the Chernobyl power plant in Ukraine exploded and sent radioactive particles flying through the air, infiltrating the surrounding soil. Despite the disaster, some plants in the area seem to have adapted well, flourishing in the contaminated soil. This ability to adapt has to do with slight alterations in the plants’ protein levels, researchers say in a study that appears in the journal Environmental Science and Technology.

“If you visit the area, you’d never think anything bad had happened there,” said Martin Hajduch, one of the study’s authors and a plant geneticist at the Slovak Academy of Sciences in Slovakia. “Somehow plants were able to adapt to the radioactivity; we wanted to understand what kind of molecule changes were going on.” He and his colleagues grew flaxseeds in contaminated soil in the Chernobyl region and compared them with flax grown in nonradioactive soil. They found that there were very few differences between the plants – aside from a 5 percent difference in protein levels.

These protein alterations may be a defensive mechanism, better enabling the plants to protect themselves from radiation, the researchers believe.

Although the plants grown in the radioactive soil appear to be healthy, they may not be safe enough for consumption, he said. “Now I don’t think anybody wants to eat this,” he said. “But one day, it may be cultivated and used for agricultural purposes.” The scientists’ report results from a first-generation round of crop growth in the study. They plan to publish results from second- and third-generation plants as well.

Sindya N Bhanoo
New York Times News Service

Oil degradation in the Gulf: How much?

Bacteria dining on the oily feast in the Gulf of Mexico enjoyed a first course made mainly of gases in the months after the Deepwater Horizon oil spill, according to a study published in Science. This may have primed the micro organisms to digest some of the more complex hydrocarbons in oil, but raises questions about how much oil degradation has actually occurred.

A team of researchers studied four hydrocarbon plumes located at varying depths and in different directions, between 0.6 miles and 8 miles from the spill site. By analysing biodegradation in the water and in lab experiments, they found that consumption of the gases most palatable to bacteria, like ethane and propane, accounts for up to 70 percent of the observed oxygen decrease in the deepwater plumes.

Though the oxygen dips have not been extreme enough to cause oxygen-starved conditions in the deep water, researchers say the impacts on marine life are still an open question. Most oil spills occur in surface waters, where gases escape quickly into the atmosphere. But in the deep waters of the Gulf, “natural gases are in many ways driving the show,” says lead author David Valentine, a geomicrobiologist at the University of California, Santa Barbara.

Apart from the estimated 200 mn gallons of oil that gushed from the wellhead, Valentine estimates that 30 pc more hydrocarbons jetted out in the form of gases. Whereas a significant fraction of oil made it to the surface, gases are more soluble in water, so “almost all of the gas stayed deep,” says Valentine. Richard Camilli, an oceanographer at the Woods Hole Oceanographic Institution in Massachusetts, says that the study “provides clear evidence that microbial hydrocarbon degradation was mostly limited to natural gas.”

Amanda Mascarelli
New York Times News Service

DH Newsletter Privacy Policy Get top news in your inbox daily
Comments (+)