STEVE INSKEEP, HOST:
We have news about photosynthesis, the basic biological machinery of plants. Scientists have re-engineered it, creating genetically modified plants that are better at converting sunlight into stalks and leaves. They hope it'll lead to bigger harvests. NPR's Dan Charles has the story.
DAN CHARLES, BYLINE: There's a big old molecule, a protein, inside the leaves of most plants. It's called Rubisco.
AMANDA CAVANAGH: So I'm a big fan of Rubisco. It's probably the most abundant protein in the world.
CHARLES: This is Amanda Cavanagh. She's a researcher at the University of Illinois. Rubisco, has one job. It picks up carbon dioxide from the air and uses the carbon to make sugar molecules. It gets the energy to do this from the sun. This is photosynthesis, the way plants use sunlight to make food, the foundation of life. So yay for Rubisco.
CAVANAGH: But it has what we like to call one fatal flaw.
CHARLES: The flaw is Rubisco is not picky enough about what it grabs from the air. It also picks up oxygen, which is unfortunate.
CAVANAGH: When it does that, it makes a toxic compound. And so the plant has to detoxify it.
CHARLES: Plants have a whole complicated chemical assembly line that handles this detoxification, and the process uses up a lot of energy, which means the plant has less energy for making leaves or food for us. So Cavanagh and her colleagues at the University of Illinois and the U.S. Department of Agriculture spent the last five years trying to fix Rubisco's problem.
CAVANAGH: We're sort of hacking photosynthesis, you could say.
CHARLES: They experimented with tobacco plants just because tobacco's easy to work with. They inserted new genes into these plants which shut down the existing detoxification assembly line and set up a new one that's way more efficient. And they created super tobacco plants.
CAVANAGH: They grew faster, and they grew about 40 percent bigger or up to 40 percent bigger.
CHARLES: Sounds kind of remarkable. You are really redesigning nature to work better?
CAVANAGH: Yeah. I mean, that's our plan, maybe not nature, though. We're redesigning an agricultural product.
CHARLES: They're now trying to do the same thing with plants that we actually rely on for food, crops like tomatoes and soybeans, also cowpeas because that's an important crop in sub-Saharan Africa.
CAVANAGH: Which is where our funders are really interested in making the biggest impact.
CHARLES: The funders include the U.S. Department of Agriculture and the Bill & Melinda Gates Foundation. The Gates Foundation also funds NPR. Cavanagh and her colleagues published their work this week in the journal Science. Maureen Hanson, who's doing similar research at Cornell University, is really impressed.
MAUREEN HANSON: This is a very important finding. It's really the first major breakthrough showing that one can, indeed, engineer photosynthesis and achieve a major increase in crop productivity.
CHARLES: These more productive crops are still years away from farmers' fields, though. Researchers have to figure out whether engineering food crops like soybeans this way actually means more beans or just more stalks and leaves. And then they'll need to convince government regulators and consumers that the crops are safe.
Dan Charles, NPR News.