Plug pulled on RNA signal to kill enemy insects

LEFT - University of Manitoba researcher Steve Whyard is using GreenLight double-stranded RNA to make flea beetles lose their appetite for canola leaves. With their source of sustenance gone, the beetles die. Beneficial insects are not affected by the foliar spray. | Steve Whyard/University of Manitoba photo
RIGHT - The Colorado potato beetle ingests the GreenLight RNA interference molecule and loses all appetite for potato plant leaves. The beetle eats only potato leaves, and without that source of nutrition, the beetle population in that potato field dies. | Canola Council of Canada photo

GreenLight Biosciences uses the biology of RNA signals to disrupt the messages that insects receive to eat certain plants

Most of society today wants farmers to reduce or eliminate chemicals they use to protect crops. Farmers want that, too. RNA signals hold the answer.

Scientists are facing a major challenge trying to figure out how to provide non-chemical crop protection remedies so farmers can continue to increase the volume of food required to feed a growing population.

Society and governments want to see results — fast. The situation has fostered major growth in university and corporate research into biological products that do not rely on commercial chemicals. Gradually, new products are becoming available that respond to consumer demands for safer more sustainable food production options.

GreenLight Biosciences is at the leading edge of that research, with its GreenWorX technology. GreenLight biologist Drew Cunningham offers a quick science lesson to remind us what ribonucleic acid (RNA) does for us.

RNA is a molecule found in all living organisms. It facilitates virtually every biological process of life, such as the way we eat, grow and behave. We’re all slaves to our RNA.

“As you recall from your high school biology class, a gene produces a protein through a messenger RNA. Our GreenLight Bio product interferes with that RNA message,” explains Cunningham, emphasizing that this is very different from technology that produces genetically modified organisms.

“For example, an insect pest wants to eat a certain commercial crop such as canola. RNA signals tell the insect it wants to feed on this specific crop. If you can intercept or interfere with that message, you have compromised the insect’s critical function in life, which is to eat canola plants. Without food, the population of that specific targeted insect dies. Beneficial insects are not harmed. The crop survives and thrives.

“We’re not doing anything at the genetic level of the insect or the crop. We’re not altering the insect. We’re not altering the crop. And it’s not a chemical poison. We apply it as a foliar spray on the leaves. The insect starts eating the leaves. Our molecule enters the insect’s stomach. Once the molecule is inside the pest, it intercepts the RNA message. The insect loses its appetite for those leaves. And dies.”

Over numerous generations, the insect has evolved to feed on that specific commercial crop. If it loses its desire for that crop, it’s toast. Cunningham says the beauty is that people opposed to chemical crop protection have no objection to this technology. You can target a specific insect without harming the beneficials.

According to GreenLight, it’s been known for years that this naturally occurring biological molecule has enormous potential for improving plant, animal and human health. Many applications have been extensively researched and validated in the laboratory. Pharmaceutical and drug discovery companies recognize the role messenger RNA (mRNA) plays in improving human health and stopping the spread of infectious disease.

However, wide commercial use has been prohibitively expensive due to RNA interference’s high cost of production and slow production time. In addition, traditional methods to create RNA also sacrifice quality.

“With our proprietary, cell-free, bio-processing method, GreenLight has found a way to produce low-cost, high-quality RNA in a safe and environmentally friendly manner,” Cunningham said. “Our work is enabling faster, large-scale production of high-quality RNA to solve some of Earth’s most pressing challenges. The beauty is that RNA works without affecting the DNA of a targeted pest.”

Mick Messman, chief commercial officer at GreenLight Biosciences, says RNA interference is the next generation of biological crop protection. He says the concept of using RNA for pest control has been used in biotechnology before. There are some products in the market that are delivered to the insect via the plant gene. There’s a corn product for corn root worm and a potato product delivered through the gene.

“But it’s been cost prohibitive until now. Our proprietary self-reproduction method is the breakthrough. It’s the most cost-effective way of producing the molecule in the volume we need. It also delivers a very high quality product.

“Our system also accelerates the process of getting a new product into the market. Because the timeline is so much shorter than with a conventional chemical product, it is therefore less expensive. If the genome of an insect is mapped, then it’s more a matter of designing than discovering. We essentially design a sequence to impact that specific insect.

“Our first product is designed to protect potatoes from the Colorado potato beetle, which feeds on potato leaves. We control that beetle, while having no impact on bees, butterflies, ladybugs or other beneficials. Our potato beetle product will be the first foliar spray product. We’ll make application for regulatory approval this year, and we expect full registration in 2022.”

By Ron Lyseng