Congratulations to Velushka Swart on the successful defence of her PhD degree on 18 May! This last stage in the completion of her degree was preceded by the presentation of her prestige seminar at the FABI auditorium. She presented a summary of her research project, titled “Functional genomics of the cercosporin biosynthetic gene cluster in the maize pathogen, Cercospora zeina”.

Her project was supervised by Prof. Dave Berger (Molecular Plant Pathogen Interactions research group) and Dr Bridget Crampton. Her external examiners were Prof. Rosie Bradshaw of the Institute of Fundamental Sciences at Massey University, New Zealand; Prof. Lisa Vaillancourt of the Department of Plant Pathology at the University of Kentucky, USA and Prof. Noelani van den Berg at the University of Pretoria.

Velushka’s research sought to understand the role of cercosporin, a phytotoxin that was thought to be essential for pathogenicity in Cercospora species that are pathogens on different hosts. She discovered through functional genomics that one of the cercosporin biosynthetic genes was defective in Cercospora zeina, thus shedding light on a long-standing puzzle as to why this fungus does not produce cercosporin in culture. C. zeina is the causal agent of grey leaf spot disease in maize. The disease causes devastating losses in maize yields and poses a threat to food security, especially in a country like South Africa where maize is a staple food crop.