Professor Barbara Howlett is a leading international fungal plant pathologist. She discovered that disease-related genes are often located in unstable parts of the fungal genome, where gene loss and mutations readily occur. This explains how disease resistance, deliberately bred into crops, can rapidly break down in the field. The practical applications of her discovery have had a major impact on the viability and profitability of the Australian canota industry. She also discovered novel biosynthetic pathways for classes of fungal toxins that are important in diseases of both plants and animals.