Flagship-backed firm is using RNA for crop protection

The venture capital firm Flagship Pioneering has publicly launched the start-up Terrana Biosciences, which is using RNA to program plants to resist pests and disease.

With a $50 million initial investment from Flagship, Terrana will use RNA from benign plant viruses as a chassis to carry other pieces of cargo RNA into a plant to help it respond to threats like viruses, fungi, and insects.

Terrana’s technology works much like a vaccine. After the product is sprayed onto crops, the RNA chassis enters the plant through tiny tears in the leaves and delivers the RNA cargo to plant cells. The cargo could act on its own to stimulate a plant’s immune response and fight off viruses, or it could be translated into proteins that help the plant, such as Cry proteins, which kill insects when the insects chomp on a plant.

Ryan Rapp, who is Terrana’s CEO and a Flagship partner, says the cargo RNA can be tailored to address multiple problems, including viral infections, insect predation, and adapting to a changing climate.

“Think of it like software,” he says. “You can stick a floppy disk or USB drive into the computer and give it a set of instructions. This is the first time we’ve had a platform where we can actually do this in plants.”

Since the chassis RNA comes from viruses that plants already tolerate, it can move freely through the plant’s vascular system. Terrana modifies the delicate nucleic acid to protect it from environmental damage while it’s sitting on leaves. For example, the company can add hairpin structures that cause the RNA to defensively curl up on itself.

Once the RNA gets inside a plant, it replicates, meaning farmers could spray the product less frequently than they spray traditional pesticides.

Mark Trimmer, president of the agricultural biotechnology intelligence firm DunhamTrimmer, says RNA usually degrades quickly, which has made it difficult to use as a spray on plants. Improving the durability of the RNA chassis improves the chances that a product will make it into the plant, replicate, and successfully carry out its instructions.

Trimmer says the company has the potential to solve a host of problems—provided the technology is cost effective. “Will the cost of goods be low enough?” he asks. “They certainly would have a wealth of opportunities.”

As it often does, Flagship developed the technology in-house, and it had the help of emeritus Pennsylvania State University researcher Marilyn J. Roossinck. Terrana joins five other agriculture start-ups launched by Flagship, including carbon-sequestration-focused Indigo Ag and the pest control company Invaio Sciences.

Terrana’s approach differs from that of companies using RNA interference (RNAi) for crop protection. Last year, the US Environmental Protection Agency allowed farmers to start using an RNAi insecticide from GreenLight Biosciences that stays on the surface of plants. When consumed by beetles, the RNA silences a gene they need to survive.

Other companies are using technologies that resemble Terrana’s. The start-up Silvec Biologics, based on technology developed by University of Maryland virologist Anne Simon, is developing a product that uses RNA to deliver peptides or small RNAs to diseased trees.

Terrana’s first products will protect corn, soybeans, and tomatoes from viruses. Farmers have no good solution for several plant viruses, Rapp says, and Terrana’s products could help.