UTM researcher solves decades-old mystery, redefines how plant metabolism is understood

Sonia Evans’s path to becoming an award-winning researcher started with her grandmother – a woman who had no formal education.

Her grandmother, who believed in the healing power of plants, made plant-based traditional medicines for people suffering different ailments, such as infertility and skin conditions, in her southern Nigerian village. 

“She knew the type of plants to go to, and made different concoctions for us,” remembers Evans, a PhD student in biology at U of T Mississauga who will be continuing her postdoctoral work at U of T Scarborough. “She never knew the names of the plants, but she knew the types of plants to put together to get the result she was expecting.”

While Evans didn’t realize it at the time, her grandmother’s work would ultimately influence her future academic career.

A student at UTM’s Phillips lab, Evans focuses on understanding how plants control carbon supply towards the production of isoprenoids – which are high-value compounds critical to plant growth, defense and crop productivity. These compounds also have significant pharmaceutical and industrial applications, making them central to sustainable solutions in agriculture and biotechnology.

In her recent work, Evans sheds light on a decades-old mystery in plant science: the origin of pyruvate in chloroplasts (which are responsible for photosynthesis). Pyruvate is a vital precursor for the production of isoprenoids, amino acids and fatty acids. Evans’s work reveals that Rubisco, nature’s most important enzyme, responsible for fixing carbon dioxide during photosynthesis, plays a surprising secondary role in supplying pyruvate.

This discovery not only redefines how scientists understand plant metabolism, but also solves a long-standing paradox of the origin of pyruvate. Evans’s findings ultimately provide a critical link between photosynthesis and the production of isoprenoids. By uncovering how plants channel carbon toward these valuable compounds, her research opens the door to innovative biotechnological strategies for engineering crops with enhanced productivity and resilience.

Evans, who always had a love for science and research while growing up, embarked on her post-secondary studies when she received a scholarship to study plant science at a private university in Nigeria. 

“I started really learning about plants and saw how fascinating they are,” she says. “Our whole existence, our survival, is dependent on plants because of all the benefits we get from them.”

When she completed her undergraduate studies, her brother encouraged her to continue pursuing plant science and biotechnology. For her master’s degree, she attended the Hebrew University of Jerusalem on a scholarship to study plant biology. 

“I started really, really getting interested in plants’ metabolism in general, and looking at how plants make various chemicals that are very important to us,” Evans says.

For her PhD studies, she looked to universities abroad with labs that aligned with her research goals. That’s when she discovered a lab at UTM led by biology professor Michael Phillips.

“He was really involved in plant metabolism. . . and really trying to understand how plants make chemicals that are important – not just for their growth, development and for photosynthesis – but also for us,” Evans says. “These are chemicals that we use as drugs, flavours, fragrances, cosmetics and biofuels. I was really interested in that part of the research.”

She adds that she was also drawn to U of T because of its reputation as one of the best universities, with state-of-the-art research facilities. However, Evans felt that getting into U of T was a long shot – and was surprised when she was accepted. 

“I was like, ‘Oh my God – who am I to be at the University of Toronto?’” she laughs. “But I wanted to be at a very good university, and I had to keep trying to aim higher and higher for myself.”

As a PhD student at UTM, Evans continued to aim high. In September 2024, she won the Roberta Bondar Graduate Student Excellence Award from the department of biology, recognizing her outstanding scientific achievements, and her recent discovery on Rubisco was featured in the prominent science journal Nature Plants. 

She balanced these accomplishments as a wife, and mother to a young child – which she says has been possible thanks to a strong support system including friends, family, peers and her spouse.

“It’s been a learning curve . . . but I have tried to take everything one step at a time, and check myself every day,” Evans says.