A medal from the King: ANU plant science legends recognised

In the early hours of one July morning this year, renowned plant scientist Professor Graham Farquhar phoned his long-time colleague and friend Professor Susanne von Caemmerer and (uncharacteristically) insisted that she check her emails.

“I’ll check them after breakfast,” the newly-retired scientist rebuked.

Retelling this story, Professor von Caemmerer laughs as she admits that email was definitely worth breaking her morning routine to read. The pair had been notified that they were to receive one of the Commonwealth’s most respected awards for science, endorsed by King Charles III himself.

Professor Farquhar and Professor von Caemmerer from the Australian National University (ANU) have been jointly awarded the Royal Medal (Biological) from The Royal Society, London. The award recognises their influential work creating a model for photosynthesis, which has underpinned the scientific understanding of leaf gas exchange for decades.

This month, Professor Farquhar and Professor von Caemmerer travelled to London to accept their medal at The Royal Society’s premier awards ceremony.

“The award of the Royal Society’s Royal Medal is a fitting recognition of the brilliant work of Graham and Susanne, as well as recognition of ANU plant science more broadly,” says Professor Kiaran Kirk, Dean of the ANU College of Science and Medicine. 

“Plant science has long been a major research strength of the University and it is wonderful to see this recognised with this prestigious award,” he adds.

A winning formula

Their collaboration began at the ANU during Professor von Caemmerer’s PhD research, which Professor Farquhar was supervising. In 1980, they published their new mathematical model to understand photosynthesis, the process by which plants transform sunlight and water into oxygen and sugars. The model is still widely used today.

“We brought several fields of research together and got them to talk to each other,” says Professor von Caemmerer, explaining why this particular model worked so well.

That included matching Professor von Caemmerer’s pure mathematics expertise with Professor Farquhar’s background in plant physiology, combined with further input from American biologist, Dr Joseph Berry.

The result was a succinct and robust mathematical model that would be practical for plant scientists to use to understand gas exchange in leaves during photosynthesis. This was backed by solid experiments to prove the theory worked.

The model can predict the rate that carbon dioxide is converted into organic compounds under different environmental conditions of light intensity, temperature, carbon dioxide and oxygen concentrations. In reverse, it can also predict the underlying biochemical properties of leaves, using gas exchange data.

Focus on the fundamentals

One feature of their success is that they worked on basic science. Or, science that is foundational to human understanding, rather than research with a specific end goal or application.

“Photosynthesis is essential for all life on Earth,” says Professor von Caemmerer, who spent majority of her career at the ANU Research School of Biology and the ARC Centre for Translational Photosynthesis.

“It is the major process that provides us with the growth of plants and therefore food. It also provides us with the oxygen we breathe, and the sugars and carbohydrates which either we eat, or other animals eat.”

Quantifying the process of photosynthesis opened the door to better understand all the plants and how they sustain us and the planet.

The pair also attribute their success to the thriving research environment they worked in at the ANU, and the strong Australian investments in plant science research.

“I would like to say a thank you to Professor Barry Osmond, who was the head of our department, who brought together a group of outstanding biochemists that gave us a great advantage,” says Professor Farquhar.

A proud legacy in plant science

“Our biggest collaboration was early on in formulating the model, and then our research often has gone in different directions,” explains Professor von Caemmerer. 

She showed that maths can go hand-in-hand with plant science – and went on to develop further mathematical models on the biochemistry of photosynthesis. Those models also remain vital to the field.

“I think I was very lucky. I’ve been able to do the research that I really, really enjoyed,” reflects Professor von Caemmerer. “So I look back on it with pleasure.”

Her work has attracted continuous funding from the Bill and Melinda Gates Foundation, and she’s been an integral part of international consortia working towards increasing crop productivity. In recognition of her excellence in photosynthesis research, she was awarded the Charles F. Kettering Award by the American Society of Plant Biologists.

“I tended to go more towards an interest in climate change and how photosynthesis should change with improving carbon dioxide concentration,” says Professor Farquahar.

His contributions at the ANU Research School of Biology have led to the development of drought-resistant wheat and higher crop yields in dry years, and he was an integral member of the Intergovernmental Panel on Climate Change when the IPCC received a shared Nobel Prize in 2007. Professor Farquhar was previously awarded the Kyoto Prize, the Australian Prime Minister’s Prize for Science, and was the 2018 Senior Australian of the Year.

Despite their many world-class achievements, both professors are prone to understatement.

“I fear we might sound ungracious,” Professor Farquhar notes, although he needn’t have worried. “In fact, we’re absolutely thrilled to accept the medal.”

“It is a great honour,” Professor von Caemmerer adds. “And I think it’s also a great honour that Australian plant science is being recognised.”

When Professor Farquhar and Professor von Caemmerer attended the ceremony to receive the Royal Medal, it was a proud moment. It was a special opportunity to celebrate their globally impactful contributions to plant science and their profound legacy.

As humble as they are, Professor Farquhar and Professor von Caemmerer deserve the limelight.