University of California-Berkeley scientists found a way to modify plant genes through a nano-needle.
Tinkering with plant genetics has puzzled plant scientists. The benefits of modifying plant genes in an efficient manner would improve the speed of breeding plant crops.
The cells need to have DNA planted into it. Although this is easier with animal cells, it is quite different when it comes to plant cells.
"Plants have not just a cell membrane, but also a cell wall," says Markita Landry, assistant professor of chemical and biomolecular engineering at the University of California, Berkeley.
There are many methods in getting DNA inserted into cells. One involves using a gene gun that shoots DNA-coated microscopic gold bullets and the other is infecting plant cells by hiding DNA inside bacteria.
The limitations of these methods involve the inefficiency of gene guns and the difficulty in infecting plants with bacteria.
The scientists from UK Berkeley innovated a method by using carbon nanotubes which are very small tubes of carbon.
"I'm a physicist," Landry says. "When I started my lab at Berkeley two years ago, my lab was focused exclusively on imaging between cells."
Landry's original aim was to use the carbon nanotubes to scaffold around the cells in order to see what happens inside these cells. "This was a project that failed pretty hard and pretty quick because instead of staying outside of the plant cells as we had presumed, these nanotubes were going straight into the cells," Landry says.
With this realization, she turned the problem into an opportunity. "We flipped it around and made it a DNA delivery platform instead," she says.
A strand of DNA is small enough to slip through the plant cell wall, but it's not rigid enough. "You can kind of think of it like a floppy string," Landry says. "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."
The nano-needle comprises the carbon nanotube with the attached DNA.
However, the lifespan of that carbon nanotube only lasts a few days. CRISPR, a gene editing tool, can be utilized to make a permanent change in the genome of the plant.
Landry provided a possibility that these carbon nanotubes can be used to deliver CRISPR. An example would be an apple tree that has its gene for browning turned off by CRISPR.
"We would end up with an apple tree whose apples don't go brown when you cut into them," Landry says.
Scientists have been intrigued by the use of carbon nanotubes to insert DNA into plant cells. "I think they've got a little ways to go to make it really interesting," says Laura Bartley, associate professor of plant biology at the University of Oklahoma.
The said findings were published in Nature Nanotechnology with arugula and wheat as plant specimens. However, the method has to be tried with different plant varieties if it works.
"If it works the way they think it does, I can imagine a lot of people wanting to use that," Bartley says.
