美国国家公共电台 NPR Scientists Thread A Nano-Needle To Modify The Genes Of Plants（在线收听）

Scientists Thread A Nano-Needle To Modify The Genes Of Plants

MICHEL MARTIN, HOST:

Researchers may have cracked a problem that has vexed scientists for decades - how to easily modify the genetics of plants. Being able to do that efficiently would make breeding new varieties of crops faster and easier. NPR's Joe Palca has more.

JOE PALCA, BYLINE: To modify the genetics of plants, you need to get DNA into plant cells. But it's hard. Researchers at the University of California, Berkeley, have invented a way to do it using something called carbon nanotubes - long, stiff tubes of carbon that are really teeny-tiny. Markita Landry is the scientist who came up with the idea. But the curious thing is she's neither a nanotechnology engineer nor a plant biologist.

MARKITA LANDRY: I'm a physicist. And when I started (laughter) my lab at Berkeley two years ago, my lab was focused exclusively on imaging between cells.

PALCA: Landry was planning to use carbon nanotubes as a kind of external scaffolding around the cells to make it easier to study what was between them. That idea was a total flop.

LANDRY: Because instead of staying outside of the plant cells as we had presumed, these nanotubes were going straight into the cells.

PALCA: So, in the spirit of corporate management gurus, Landry turned a problem into an opportunity.

LANDRY: We flipped it around and made it a DNA delivery platform instead.

PALCA: Getting DNA into cells would allow scientists to manipulate the way plant cells work. And there are some exotic ways of doing that. But plant cells present a unique challenge.

LANDRY: Plants have not just a cell membrane but also a cell wall.

PALCA: A strand of DNA is small enough to slip through the plant cell wall. But it's not rigid enough.

LANDRY: You can kind of think of it like a floppy string. If you try to push a floppy string through a sponge, it's not really going to work. But if you take a solid needle and try to push it through a sponge, that will work much better.

PALCA: Attaching the DNA to the carbon nanotube gives you that nanoneedle. In addition to DNA, Landry says it's also possible to attach a gene editing tool known as CRISPR. Once inside a cell from, let's say, an apple tree, CRISPR could, for example, inactivate a gene that causes browning in apples.

LANDRY: We would end up with a apple tree whose apples don't go brown when you cut into them.

PALCA: Now, Landry's approach is brand new. Laura Bartley is a plant biologist at the University of Oklahoma in Norman.

LAURA BARTLEY: I think they've got a little ways to go to make it really interesting.

PALCA: She says it's important to show that it works in different varieties of plants. But she's impressed that the new approach appears to be able to get DNA into grass plants like wheat.

BARTLEY: That's the technology that I'm, like, oh, that's pretty cool. If it works the way they think it does, I can imagine a lot of people wanting to use that.

PALCA: In fact, Bartley is thinking about trying the new technique for her work on grass plants.

Joe Palca, NPR News.