Prozac for Plants

Pyrococcus furiosus, photographed by Henry Aldrich of the University of Florida.

The researchers have already introduced a P. furiosus gene into a small, fast-growing plant known as arabidopsis. "We have our first little seedlings," says Boss. "We'll grow them up and collect seeds to produce a second and then a third generation." In about one and a half to two years, they hope to have plants that each have two copies of the new genes. At that point they'll be able to study how the genes perform: whether they produce functional enzymes, whether they do indeed help the plant survive, or whether they hurt it in some way, instead.

Eventually, they hope to pluck genes from other extremophile microbes - genes that will enable the plants to withstand drought, cold, low air pressure, and so on.

The goal, of course, is not to develop plants that can merely survive Martian conditions. To be truly useful, the plants will need to thrive: to produce crops, to recycle wastes, and so on. "What you want in a greenhouse on Mars," says Boss, "is something that will grow and be robust in a marginal environment."

In stressful conditions, notes Grunden, plants often partially shut down. They stop growing and reproducing, and instead focus their efforts on staying alive - and nothing more. By inserting microbial genes into the plants, Boss and Grunden hope to change that.

"By using genes from other sources," explains Grunden, "you're tricking the plant, because it can't regulate those genes the way it would regulate its own. We're hoping to [short-circuit] the plant's ability to shut down its own metabolism in response to stress."

Genetically engineered plants growing in Boss and Grunden's lab.

If Boss and Grunden are successful, their work could make a huge difference to humans living in marginal environments here on Earth. In many third-world countries, says Boss, "extending the crop a week or two when the drought comes could give you the final harvest you need to last through winter. If we could increase drought resistance, or cold tolerance, and extend the growing season, that could make a big difference in the lives of a lot of people."

Their project is a long-term one, emphasize the scientists. "It'll be a year and a half before we actually have [the first gene] in a plant that we can test," points out Grunden. It'll be even longer before there's a cold- and drought-loving tomato plant on Mars - or even in North Dakota. But Grunden and Boss remain convinced they will succeed.

"There's a treasure trove of extremophiles out there," says Grunden. "So if one doesn't work, you can just go on to the next organism that produces a slightly different variant of what you want."

"Amy's right," agrees Boss. "It is a treasure trove. And it's just so exciting."