Defending canola from fungus

Blackleg, a devastating fungal disease in Australian canola crops, has been and continues to be a huge economic problem for the export industry in Australia. It has taken over 20 years to understand and manage it. Research into it has been the task of a dedicated group led by Professor Barbara Howlett from the University of Melbourne’s School of Botany in collaboration with experts overseas. 

Professor Howlett says her early research was a mixed bag of projects. Her first published paper was on antibody levels in asthmatic children and she worked in several research fields including pollen allergy, immunology, memory in bacteria, and bread mould. 

But retrospectively, she says, the work gave her a useful multidisciplinary background to access in tackling the Blackleg fungus problem in canola. 

“Women often have disjointed careers, as they are juggling family responsibilities,” Professor Howlett says. 

“Tackling lots of different research problems meant I had to be a flexible research thinker. 

“Also, more than 20 years ago I was lucky enough to work at Stanford on a model fungus, the bread mould Neurospora. So when I came back to Australia I applied the skills I acquired to a problem in agriculture.”

Professor Howlett says she chose to work on the canola Blackleg pathogen, Leptosphaeria maculans, because at the time the fledgling canola industry was expanding, and it seemed likely that Blackleg would become a severe constraint, which indeed it did. 

“I am fortunate to have received continuous funding for canola research from the Grains Research and Development Corporation, which invests funds from farmers and the federal government to address issues faced by Australian grain growers,” she says. 

Professor Howlett’s research ranges from the “genome to paddock”: Her team has analysed the genome of the Blackleg fungus to create strategies that farmers can use to control the disease. 

“We knew the resistance to the fungus in crops was quickly overcome if farmers planted one variety extensively in a region, so we located the key ‘effector’ genes and predicted they must have been in unstable in parts of the genome, which they were,” she says. 

“With the knowledge that virulence of the Blackleg fungus is connected to these effector genes, we now had a molecular tool to rapidly monitor disease across Australia. 

“We can now tell farmers before they plant their crops the risk of that canola variety developing Blackleg disease. If the risk is high, then the farmers can choose to plant another variety.” 

Professor Howlett says the journey from PhD student to Professor has been an exciting one. 

“The advent of molecular biology and the genomic technologies has meant rather than looking at one gene or protein at a time in a fungus – or indeed in any organism, we can now examine thousands,” she says. 

“In the future, we will need to interpret this immense amount of data to enable a more organism-wide approach to understanding pathways involved in disease and other processes.”

Professor Howlett’s team also studies fungal diseases on mustard and her latest paper describes the fungal genes involved in disease. 

She says her version of looming retirement plans includes new projects to work on and people to mentor.

http://www.botany.unimelb.edu.au/botany/