INTERVIEW WITH DR JASON BRAGG

SENIOR RESEARCH SCIENTIST, BOTANIC GARDENS OF SYDNEY

From plants and bacteria to lizards and animals, Dr Jason Bragg’s genomic journey has been nothing short of fascinating. Dom Sweeney spoke to the research scientist about what makes him tick.

Where did your passion for biology begin? My journey in biology started in high school – I loved science but gravitated towards biology. That led to an undergraduate degree in environmental science with a focus on ecology. I was equally interested in plants and animals, but I chose animals and lizards for my undergraduate honours. I worked as a plant ecologist for a while but then made a big switch, moving abroad to start a biology PhD at the University of New Mexico in 2001. I became enchanted by bacteria and their genomes, in ways related to ecology.

What was the catalyst for you to start studying bacteria?

In a seminar I saw a picture of a DNA molecule and thought, there are a lot of nitrogen atoms there. I wondered if the quantity of nitrogen atoms that bacteria use to build their genomes might change in response to how much nitrogen is available to them. That question motivated me to start thinking more about bacterial DNA and proteins and asking questions of genomics inspired and motivated by ecological questions. A job in Boston followed, working on marine bacteria, thinking about how the content of their genomes was matched to their environment.

Marine bacteria genomics to plants – that’s quite a big move. It was! After Boston I returned to Australia, to the CSIRO where I was working on trees. After that was ANU where

I worked on lizards with a genomic emphasis. Then in 2016, I moved to start working on plants at the Gardens.

How does your expertise assist in areas like restoration and conservation?

In the Research Centre for Ecosystem Resilience (ReCER), we study plant genetics to inform conservation and restoration. When working on a species of conservation importance, or a threatened species, our chief concern is to ensure newly established populations of plants have enough genetic diversity to protect them from inevitable challenges. If people plant out a population, it’s hoped some number of individual plants carry the gene required to face, for instance, a new pathogen in 1,000 years, or face a drought in 20 years. The plants need that genetic diversity to respond evolutionarily to future challenges. With conservation, we make recommendations about maintaining or translocating endangered species from the Gardens’ nurseries. We also make recommendations about saving genetic diversity to try to avoid inbreeding. The principles are often similar: we collect genetic data, characterise patterns of variation in the species of interest, and then make recommendations on promoting genetic diversity without bringing together things that are too different.

What does your typical day look like? It varies. Right now, there’s lots of field work. Yesterday I went to collect a sample of beach spinifex, which as you can imagine is a fun plant to sample [laughs]. I’ve been working with some Melaleuca species, some of which are very important components of swamp habitats, so there’s been some swamp field work, and that’s been fun. Other days, as a computational biologist, I’m actively writing code. Apart from science,

I’m working with and mentoring early career researchers, which is a blast.

Tell us about your work with myrtle rust. Myrtle rust was first detected in Australia in 2010, probably arriving from overseas. It’s caused by a fungal pathogen. Some species have become critically endangered because of it. We’ve been working on Melaleuca quinquenervia (broad-leafed paperbark), a dominant species in swamps. Researchers have previously noted that it shows variable resistance to myrtle rust, so we’re interested in trying to understand the genetics of that. We did a study where we measured resistance in seedlings, then looked for genetic associations between variation at particular locations in the genome, and the measured rust resistance of seedlings. We were able to find some markers, and that’s work we’re now validating. It appears to be possible to find a small set of markers that are predictive of whether a seedling will be resistant or susceptible to this pathogen. Next, we try to develop a relatively inexpensive genetic test to be applied to seedlings. With revegetation, we try to promote both the genetic diversity of the planted population, and to make it more enriched than would usually be the case.

Aside from saving species, what gets you out of bed?

Outside of research and science, a few mornings a week it’s swimming and running that get me out of bed the most – I guess it’s important to think about the balance between work and hobbies!

What are your proudest achievements during your time at the Gardens?

My proudest achievements are those that have resulted in or contributed to ‘plants in the ground’ outcomes. Then there’s the other side – watching the progress of the students I work with. I feel incredibly proud of that.