Dr Philip Brewer – Hemp and barley research on the knowledge frontier

Phil Brewer in glasshouse

Dr Philip Brewer is making the most of his recent Australian Research Council (ARC) Future Fellowship, using his knowledge of hormone production and function in plants to help with increasing yield stability in barley and to help the newly permitted research on hemp to make it a more productive and optimised crop for cultivation.

Originally a high school teacher, Philip chased his curiosity of plant biology into an Honours degree at Melbourne University and later a PhD at Monash University. His research work during this time focused on pollen development, while later moving onto working with Arabidopsis, and now barley and hemp. His earlier work unveiled the role of hormones for plant growth and development, and he is bringing that knowledge to his crop work now.

When expanding his work to include crops like hemp, Philip immediately realised that the branching variation he saw among hemp varieties could be due to differences in hormone pathways, specifically a hormone compound called strigolactone. Strigolactone controls the number of branches that grow on the plants, as well as the growth of symbiotic fungi on the roots.

Hemp research is a controversial research topic, due to the social stigma associated with the plant. However, the health benefits of adding hemp to our diets should not be underestimated. Industrial hemp can be cultivated for oil and seeds, rich in vitamin E and a great immune system booster, as well as omega-3 and omega-6, for reducing cholesterol and high blood pressure. The controversy surrounding hemp makes it a tightly regulated research subject, but aside from this, the actual science brings its own challenges too. Phillip explains one such roadblock in the lab is the innate coping mechanisms plants have, which counteracts traits introduced in genetic variants of his research plants. For example, when strigolactone was adjusted to increase branching, the plant would compensate for the disturbance in hormone levels, and produce less seeds on each branch. “The organism has evolved rigid growth responses, and if you try to change it, the organism resists strongly to return to equilibrium.”

Another challenge for Phillip and his team is the amount of strigolactone hormone produced in the plant - it is so minute that it initially it was beyond the detection level of currently used machines, further complicated by the fact that such hormones break down extremely quickly. Working on hormone pathways is often like looking for a needle in a haystack, as small, often temporary, changes in levels can cause substantial changes for the plant. In some instances, hormone levels can be detected but by the time of processing and examination of tissue, it can already be metabolised by the plant. Luckily, being able to use the latest equipment in Japan provided Philip with the greater resolution he needed for his samples, finding a way to overcome this roadblock too. 

The Future Fellowship has allowed Philip to freely continue his research at the Waite campus, where he is bridging the gap between fundamental and applied research by including work on plant growth regulators that are already used widely in industry. Having no restraints on furthering his research, he has high hopes for the future of hormone research and the benefits the results can provide. There is a lot of potential for hemp as a new crop for food and fibre, but the lack of systematic breeding and study of the plant make it an interesting blank canvas for Philip to do his research on.

That makes it exciting and daunting at the same time because there’s so much that we don’t know, but I love that edge of the knowledge frontier. We’ve made some really good discoveries, which have unlocked new areas in hormone biology. As a whole, this work will add to society’s information base, and might become useful in the future.Dr Philip Brewer

Have a look at Philip's research profile here

Written by Le Nguyen and Lieke van der Hulst, 21/12/21