UFV biochemist Harley Gordon helps uncover major discovery about salicylic acid

Dr. Harley Gordon in a science lab on the UFV Abbotsford campus.

Sometimes when conducting research, scientists make unexpected discoveries that change how we understand the world.

In Dr. Harley Gordon’s case, the unexpected discovery came while he was studying how salicylic acid is synthesized in plants. Harley, an assistant professor in biology at the University of the Fraser Valley, was part of a team that recently discovered a brand-new mechanism of phytohormone synthesis in a range of plant species. This kind of discovery matters because salicylic acid plays a central role in how plants keep themselves healthy.

Salicylic acid, the plant compound that inspired the creation of Aspirin, plays a central role in plant immunity — and now researchers better understand how it’s made.

“We’ve discovered the main way that most plants appear to create salicylic acid,” Harley notes. “We’ve identified brand new biosynthetic enzymes for the natural production of salicylic acid.”

Harley began this research project with a team from the University of Victoria while completing his doctoral studies. He has continued to contribute since joining UFV in 2024, using chemistry labs on the Abbotsford campus.

Dr. Harley Gordon

The research team that Harley is part of worked out a brand-new biosynthetic pathway for salicylic acid. They used a combination of CRISPR-Cas9 genetic engineering to test the functionality of potential biosynthetic genes, metabolomics to monitor whole plant hormone changes, and biochemical enzyme assays to prove their theories.

Their results were published in the October, 2025 edition of The Plant Cell , one of the top journals in plant science.

Salicylic acid is a plant hormone that mediates how plants respond to biotic stress, such as insects, fungi, and bacteria. It also has a long history of use by humans for pain relief. Extracts from poplar and willow bark have been used as analgesics for thousands of years and were the original source for the Aspirin medication.

Salicylic acid is also one of six major hormones that help control growth and help plants defend against insects. To understand why this is important, Harley explains what plant hormones actually do — especially when plants are under stress.

“Plants, like humans, rely on hormones to do all sorts of things,” he notes. “Phytohormones control how plants grow, what shape they are, when they make flowers, and how they respond to stresses like being eaten by insects.

“Plants are sessile, which means they cannot run away when they are exposed to stressors. During stressful times, such as drought, being eaten by animals, or frost, they often experience spikes in certain hormone concentrations, and that can cause changes in their biochemistry as the plant is trying to adapt or defend itself from damage.”

One of the biggest surprises came when the team realized that the plant used in most lab experiments doesn’t behave like most plants when it comes to salicylic acid.

Dr. Harley Gordon and a young visitor at UFV’s recent Open House.

The game changer for Harley and his colleagues was the discovery that using Arabidopsis (part of the Brassicaceae plant family) as a model plant was misleading, because Brassicaceae plants do not synthesize salicylic acid in the way that 99 percent of plants do.

Similar to lab mice, Arabidopsis are the “go to” model in plant experiments, which in this case was problematic.

“We didn’t know how salicylic acid is synthesized in plants,” says Harley. “But we knew it was complicated. And our research results are changing what we know about plant immunity and how plants respond to biotic stress. Prior to our work, what we did know about salicylic acid synthesis relied on Arabidopsis literature. It turns out they are weird, an anomaly. Arabidopsis plants have lost the ability to synthesize salicylic acid in the way that most plants do.

“Through our research we have shown how salicylic acid is made in plants, and that the conventional wisdom from the model species Arabidopsis doesn’t apply to the vast majority of plant species. This means that previous work in Arabidopsis tells us very little about salicylic acid in wheat, blueberries, corn, rice, or soybeans. With our work we show how easy it has been to just assume that the prior assumptions were correct.”

In practical terms, earlier research based on Arabidopsis may not apply to crops or fruit-bearing plants — a major shift in the field.

This information dramatically improves understanding of plant hormones at a very fundamental level. Harley notes, and will be used to help scientists working on improving stress tolerance in crops and understanding plants adaptation to climate change. Understanding the real pathway behind this hormone gives scientists clearer insight into how plants adapt, defend themselves, and cope with climate stress.

Two other papers making the same discovery have been published simultaneously, corroborating the results of the research team Harley is working with.

You can find out more about the results and the scientific publication here: Salicylic acid biosynthesis via the PAL pathway requires benzaldehyde synthase and a benzyl salicylate-specific esterase | The Plant Cell | Oxford Academic

If you want to learn more about plants, their biochemistry, or natural products, reach out to Dr. Harley Gordon through his UFV email at Harley.gordon@ufv.ca