Miércoles 2 de Noviembre de 2005, Ip nº 133

Bacterial genes could put plants on Mars
Por Kelly Young

Biologists have embarked on a project to engineer plants that could withstand the harsh environment of Mars, using genes from hardy bacteria that thrive around deep-sea vents on Earth.

It is one of the schemes given further funding by the NASA Institute for Advanced Concepts, which promotes futuristic ideas on the leading edge of innovation.

Humans would need oxygen, food and some form of carbon dioxide removal system to live on Mars. In theory, this could be achieved using plants, and it would be less expensive than constructing habitats to simulate the Earth.

But those plants would need to be able to cope with the stress of living in the extreme temperatures of Mars, and the planet’s higher radiation levels. So Wendy Boss and Amy Grunden at North Carolina State University in Raleigh, US, are examining whether plants could be altered by harnessing micro-organisms that live in extreme environments on Earth.

Super stressful
In plants, environmental stresses such as temperature extremes, drought or too much light, lead them to produce negatively charged oxygen molecules called superoxides. These are toxic and can harm the plant if they build up to a high level.

All plants have ways to mop up with superoxides. But the researchers believe the methods used by “extremophiles”, such as a bacteria called Pyrococcus furiosus, may be even better.

P. furiosus bacteria thrive near deep-sea vents, where very hot water jets out of the ocean floor. But they can also cope when they are driven into colder waters by ocean currents. This means that, unlike plants, their detoxification mechanism works over a huge temperature range, similar to that on Mars.

“If we could introduce genes from extremophiles that would help get rid of reactive oxygen species, that would help prime the plant for dealing with extreme environmental conditions,” says Grunden.

Arctic chill
At the moment, researchers have confined their work to cell cultures and have shown that when plant cells express the P. furiosus gene, they can withstand higher temperatures.

They aim to move on to the arabidopsis plant and try out more genes from P. furiosus. They will also examine the potential of genes from a bacterium that prefers the Arctic chill. Ultimately they hope to produce genetically modified space crops.

Four other concepts also received more NIAC funding in the latest round:

• A "star-shade" to enable a space telescope to see new worlds

• A deep-field infrared observatory to be sited near the Moon's pole

• A laser-trapped mirror for a large space telescope

• Microbots for exploring other planets


  14/10/2005. New Scientist Magazine.