Seminar by A/Prof Simon Williams: Catalysts of Deception: Unveiling Fungal Nudix Effector Protein Function in Plant-Fungal Interactions

Seminar Title: Catalysts of Deception: Unveiling Fungal Nudix Effector Protein Function in Plant-Fungal Interactions

Abstract: Our research endeavours to unravel the intricate molecular mechanisms employed by pathogenic fungi to manipulate host plants and induce disease. Additionally, we aim to understand how plants recognise fungal virulence proteins, thereby activating defence pathways.

In this seminar, I will present our latest findings focusing on two familys of effector proteins utilised by diverse pathogenic fungi during plant infection. These effector families both belong to the ancient enzyme superfamily known as Nudix hydrolases.

We show that fungal Nudix effectors can be categorised into two evolutionary and functionally distinct groups. The first group is exclusive to rust fungi from the Melampsora genus. Our results demonstrate that these enzymatic effectors specifically hydrolyze the protective 5′ cap structure on mRNA. The second group of Nudix effectors is utilised by numerous economically significant pathogenic fungi, including Magnaporthe oryzae, the causative agent of rice blast disease. We demonstrate that this conserved class of effector proteins specifically hydrolyse inositol pyrophosphates, which activate the phosphate starvation response in plants. By hijacking this pathway, fungal pathogens deceive the plant into suppressing its own defence mechanisms, thereby aiding in colonization and disease progression.

To conclude, I will discuss how we are currently leveraging this newfound knowledge to develop innovative approaches aimed at reducing fungal virulence and enhancing plant disease resistance.

Simon Williams Bio: Simon is an Associate Professor and Australian Research Council (ARC) Future Fellow at the Australian National University, where he leads the “Plant Structural Immunology” research group within the Division of Plant Science in the Research School of Biology.

Simon’s research endeavours focus on unravelling the intricate mechanisms underlying plant responses to biotic stress and the molecular pathways that adapted pathogens target to cause disease. His innovative research program combines structural biology, protein biochemistry, synthetic biology, and plant biology to dissect these complex systems.

With a keen emphasis on interdisciplinary collaboration, Simon and his team aim to develop novel strategies for disease prevention in plants. Simon is also a passionate Crows supporter and is optimistic about the year ahead.