Barbara Howlett

howlett barbara

You started your graduate career studying pollen in daisies and ryegrass. How did you transition to studying plant pathogens like Leptosphaeria maculans?
Well, a lot of career moves are serendipitous—that was the case for me. I acquired a range of skills working in different fields, not just in studying pollen, but also bacterial chemotaxis, immunology, etc., and it's meant I've been able to apply that knowledge and not been too daunted about changing focus. I worked in some outstanding laboratories. I was lucky enough to work at Stanford on a model fungus—the bread mold Neurospora crassa—with the late David Perkins, a pioneer in fungal genetics. When I came back to Australia I applied those skills to a problem in agriculture—this particular fungal disease. In science in Australia, you really have to pick a problem that has some sort of national benefit. I chose the canola pathogen Leptosphaeria maculans because it is a problem for an important export industry for Australia and therefore the funding source is much more reliable than the Australian equivalent of the NSF or the NIH. I've been able to apply myself to that particular problem over the past 20 years or so.

In Australia, grain farmers give 1% of the "farm gate value" of their product, and which is matched by the federal government, and that goes out to research and development on 26 different crops. In other words, farmers are directly funding research. I've been lucky enough to have them invest in my research. My research spans from genome to paddock, where we apply our findings from genome analysis to develop strategies that farmers are using to control this devastating fungal disease.

In a recent paper in Nature Communications, you and your colleagues report on the genome sequence of L. maculans. You made some interesting observations about effectors—proteins that change the host to better enable infection. Can you describe those findings?
We'd always been aware that the virulence of populations of this fungus in the field change very quickly, as resistance bred into canola is very quickly overcome if farmers planted one variety extensively in a region. So we thought that the key effector genes might be in an unstable and dynamic environment in the genome. And indeed that is the case. They are embedded in junk DNA, chunks of degenerated transposable elements. This location means that effectors can be easily lost, gained, or mutated, which can lead to changes in virulence. Putting together that sort of paper, which involves so much data and so many people, was a great achievement; particularly by my French colleagues, who did much of the work and coordinated the project.

Where do you see your field in 10 years?
We're now in a transition, going from looking at one gene at a time to mining genome sequences. Unsurprisingly as we take this global approach, we are finding that interactions between plants and fungal pathogens are extremely complex.
The field is moving toward systems biology, where we try and understand interactions in terms of networks between metabolic and signaling pathways. We are still looking at one piece of the puzzle at a time, but in ten years’ time we'll have a more organism-wide approach.

If you had to change careers today and you could do anything, what would you do?
I'm very happy with what I do. If I had to change, I would choose a career where I spend a lot of time outdoors. Perhaps a naturalist guide or something like that.

What’s your favorite science book?
I really enjoyed The Common Thread. It was written by John Sulston and a journalist named Georgina Ferry. It's about worm biology, Caenorhabditis elegans, and also about the race to sequence the human genome. I found it terrific.

What is something about you that most people don’t know?
I was brought up on a sheep farm. I cut saffron thistles over summer with a mattock (a hoe). The sheep wouldn't graze in these areas with the thistle. In hindsight, the amusing thing about this job is that the neighboring farmers upwind of us never cut their thistles, so my efforts were a waste of time. But at least I got paid.