Genetically modified plants have existed for many years, but the processes used to make the modifications are surprisingly inefficient. Researchers at the University of California Berkeley have developed a technique that could make plant genetics considerably more precise. Rather than the “spray and pray” approach, scientists might soon be able to use a carbon nanotube needle to inject new genetic components.
The DNA inside plant cells is not fundamentally different than that in animal cells, but the structure of the cell is problematic. Plant cells have a membrane and a thick wall composed of sugar and proteins. Fiddling with the DNA inside animal cells is a relatively simple matter because they lack that cell wall.
Currently, getting DNA into plant cells to create new genetic variants involves one of two techniques. Scientists can prepare bacterial cells known as Agrobacterium with a desired gene inserted into their genome, and then allow them to incubate with plant cells. The bacteria can transfer those genes to some of the plant cells. Alternatively, you can coat metal nanoparticles with DNA and blast plant cells. Some of them will end up with new DNA inside the nucleus where it can become active.
Berkeley scientist Markita Landry had intended to use carbon nanotubes to build a scaffolding to stabilize cells for microscopic examination. However, the project failed because the scaffolding kept piercing the cells. At that point, the team realized they might have discovered an unexpectedly efficient way to get DNA into cells. DNA is thin enough to pass through plant cell walls, but it’s not rigid enough to avoid getting stuck. If you attach it to a carbon nanotube needle, it can get inside with no problem.
So far, the team has shown that carbon nanotubes can get DNA into plant cells like arugula and wheat. The DNA persists for a few days before it degrades, but it may be possible to make permanent changes with the nano-needle by also inserting CRISPR sequences.
This technique has attracted interest from other research teams, but it will take time before anyone uses it to produce crops for human consumption. The first order of business is making sure it works reliably on plant species other than the two cited in the study.
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