Plant transformation via biolistics

One of TechAccel’s science advancement projects, supporting a biopesticide trial with the Donald Danforth Plant Science Center and the start-up company Plastomics Inc., has researchers taking “target practice” in the lab delivering DNA into tobacco plants using a gene gun.

Just another day at the shooting range!
From left, here’s Ian Curtis, Senior Scientist, at Plastomics, and Jeffrey Staub, Ph.D., of TechAccel and Plastomics.

The target practice is part of a research project, called “Danforth Biosprey,” led by Nigel Taylor, Ph.D, Interim Director of the Institute for International Crop Improvement. The project uses RNA interference (RNAi) to target a pest, the tobacco hornworm. RNAi is an attractive technology for insect control because it can be designed to be extremely specific to a particular insect type, and is inherently safe for other organisms (including humans) and the environment.

At this stage of the project, the team is focused on getting the RNA into the target tobacco plants. That’s where the gene gun comes into action, to perform the “biolistic transformation” that creates a genetically modified plant (GMO) that will make (express) the desired RNAi.

Jeffrey Staub, Ph.D., a TechAccel science advancement program manager, has his finger on the trigger, so to speak. He has deep expertise with biolistic transformation, and explains what’s so exciting about this gene gun technique.

“There’s a lot of precedence for inserting genes into the plant’s nucleus,” he said. “But with the gene gun, we’re inserting a gene into the chloroplast, not the nucleus.”

Some of the Gene Gun supplies including screens and burst-plates. And a tobacco leaf, ready to be “shot,” essentially like a mini-shotgun with pellets made of gold that are coated with the DNA to be inserted into the plant.  It’s crude, but it works well and is in common use. This method is also commonly used for nuclear transformation.

This is beneficial for a few reasons: Traditional engineering has inserted so many traits into the nucleus that it’s become difficult to manage. But there’s plenty of room in the chloroplast. “It’s much simpler and easier to manipulate,” he said.

Second, since the chloroplast is transmitted via seeds from female plants, the transgenes move easily to the offspring. And finally, since the chloroplast is transmitted from the females only, there’s no danger of “pollen drift” – what happens when pollen from transgenic male plants meanders to other fields or crops, introducing those transgenes elsewhere.

In addition to his role on this project, Jeff is also the founder, president and chief science officer of a startup biotech company, Plastomics Inc., which is using gene gun technology to introduce new traits into corn via the chloroplast – something never before accomplished.

Stay tuned. This project has several steps ahead, and we’ll report on our progress here.