They want to modify the RNA of everything.

How Plant 'Vaccines' Could Save Us From a World Without Fruit

https://www.discovermagazine.com/environment/how-plant-vaccines-could-save-us-from-a-world-without-fruit

Researchers are formulating unconventional solutions for tree diseases that harm beloved foods like oranges and chocolate. These include a potential RNA therapy, similar to certain COVID-19 vaccines…

Anne Elizabeth Simon, a virologist at the University of Maryland, is attempting to create what she calls a "vaccine" for crops that could protect our food supply.

Like the current approach to the COVID-19 pandemic, researchers have long dealt with pathogen spread among plants by quarantining infected flora to spare surrounding ones. And, depending on the type of disease, plants may also receive pesticides or antibiotic sprays. But to offer more reliable protection, Simon is part of a team developing a vaccine-like solution as an efficient and relatively quickly deployable solution to preempt — or possibly cure — plant diseases.

This potential fix can’t come fast enough…

Most of these diseases don’t have a simple treatment, and require several costly, time-consuming strategies to mitigate the diseases once they've spread. They can also be difficult to detect because, in some cases, several years pass before symptoms appear. Of course, plant pandemics are no new challenge. In the first half of the 20th century, for instance, a disease caused by fungus killed more than 3 billion American chestnut trees. But overall, climate change, ramped-up global travel and neglect by governments and industry have combined to create a perfect pathogen storm that endangers our food supply. “The time has come to let people know that there are other pandemics going on,” Simon says. “There’s multiple ones happening with trees, and it’s going to lead to a very different world.” The readily available tools can’t always curb encroaching pathogens, as proven by Florida’s quickly spiraling citrus industry — though some claim that regulators and growers worsened conditions by not acting quickly enough.

Citrus trees have already grappled with multiple pathogens over the last few centuries, including the 1800s root rot epidemic and the citrus tristeza virus that cropped up in the 1930s. Most devastating of them all, huanglongbing (HLB) — also commonly called citrus greening — originated in China and has wreaked major havoc over the past two decades.

Where Tree “Vaccines” Come In

Simon joined the fight against plant pathogens by chance: While studying plant RNA viruses in her lab, she happened upon a surprising sample in a genetic sequence database that contradicted her 30 years of research. It turned out to be a new type of virus-like RNA that she named iRNA. It shocked Simon because iRNA lacks certain genes found in all normal plant viruses, yet can still move between cells in a plant’s veins by attaching to plant-generated movement proteins.By tweaking the iRNA to carry tiny fragments of a virus, it can provoke plant enzymes to chop up the harmful virus into little pieces, without causing damage to the plant. “This can be a vehicle, not just for one type of tree, but for many,” Simon says. “It’s all because of this very unusual, never-before-seen property.” The iRNA sample was first discovered by University of California, Riverside researchers in the 1950s when it appeared in limequat trees. They found that the iRNA can infect many citrus species with very mild to zero symptoms. Yet its disease-eradicating properties were only recently discovered when Simon identified the missing genes that allow it to move through plant veins.

“This could become one of the important tools in the belt of the industry and farmers to keep citrus going,” says Georgios Vidalakis, a plant pathologist at the University of California, Riverside, and director of the Citrus Clonal Protection Program. “It looks very promising. Still, there is a lot of work to be done."

Eager to get the ball rolling, Simon founded a company called Silvec Biologics in 2019 and is working to develop a single-step vaccinelike preventative treatment that tricks trees into eradicating not only viruses that cause disease, but also fungi and bacteria — somewhat similar to how mRNA jabs force our immune systems to cook up COVID-19 antibodies. Because the trees containing the original iRNA sample have remained alive for more than 70 years, Simon says it suggests that the vaccine could possibly offer lifetime protection against several pathogens when put into newly planted trees — similar to giving children a standard set of shots. What’s less clear, however, is whether highly degraded trees that have been infected for several years can still benefit from the treatment.

Simon hopes that the iRNA therapy can save infected trees that don’t yet show symptoms of disease.