Overview

Barbara J. Howlett Professor bhowlett@unimelb.edu.au Academic Profile

We study blackleg of canola (Brassica napus), a disease caused by the fungus Leptosphaeria maculans (Life cycle). Canola is an important Australian industry, in terms of both export income and as a break crop controlling root diseases of cereals. Our research is focused on the blackleg fungus whose genome is currently being sequenced. We are applying molecular genetic techniques to the blackleg fungus to understand: gene expression during infection strategies the fungus uses to attack the plant (pathogenicity mechanisms) biosynthesis of secondary metabolites such as the toxin, sirodesmin PL changes in virulence and neutral markers in Australian field populations Our overall objective is to develop improved strategies for control of this important disease.

Our research is funded by the Australian Grains Research and Development Corporation, the Australian Research Council, and the Victorian Centre for Plant Functional Genomics. Our activities include:

• developing strategies to deploy durable blackleg resistance in canola cultivars, with Dr Steve Marcroft, Marcroft Grains Pathology, Horsham and Dr Phil Salisbury, Faculty of Land & Food Resources, The University of Melbourne and DPI, Victoria
• identifying mechanisms whereby the frequency of avirulence genes in fungal populations changes in response to selection pressure from disease resistance genes in canola
• jointly leading the Leptosphaeria maculans Genome Initiative with Dr Thierry Rouxel and Dr Marie-Helene Balesdent, INRA, Versailles, France and Genoscope to provide the sequence of the L.maculans genome to 10-fold coverage
• characterising the biosynthetic gene cluster for the blackleg toxin, sirodesmin, with Prof. Soledade Pedras, University of Saskatchewan, Canada and understanding the role of this toxin in blackleg disease
• studying evolution and regulation of gene clusters for the biosynthesis of toxins related to sirodesmin, including gliotoxin, which is implicated in aspergillosis of humans
• developing tools for understanding pathogenicity mechanisms of another important fungal pathogen of canola, Sclerotinia sclerotiorum