PS PhD Exit Seminar: WAK Attack! How wall-associated kinases recognise fungal effectors in wheat and canola

ABSTRACT

Plants detect invading pathogens using immune receptors that are located both inside the cell and at its surface. Structural and biochemical studies have transformed our understanding of how intracellular immune receptors recognise effector proteins secreted by pathogens. But far less is known about how plant cell-surface receptors recognise effectors in the apoplast – the space outside the plant cell where many fungal pathogens colonise their hosts. Wall-associated kinases (WAKs) are a distinct and comparatively understudied family of cell-surface receptors, thought to sense damage-associated molecular patterns such as pectin fragments released from the plant cell wall. More recently, WAKs have emerged as isolate-specific resistance genes across several crop species, yet how they recognise proteinaceous pathogen effectors has remained unclear.

In this seminar, I will present my PhD research on WAK-mediated effector recognition in two important crop pathosystems involving wheat and canola – altogether combining techniques in structural biology, protein biochemistry, biophysics and in planta assays. In the wheat – Zymoseptoria tritici pathosystem, I will focus on Stb6, the first cloned resistance gene against Septoria tritici blotch, and AvrStb6, the effector it recognises. Integrating structural biology of this effector with biophysical and in planta experiments, I will uncover how the fungal pathogen has evolved to evade recognition. Crystal structures of other recognised effectors from Z. tritici will also offer insights into this pathogen's wider effector repertoire. In the canola – Leptosphaeria maculans pathosystem, I will show how biochemical and biophysical approaches, paired with recent advances in ab initio structure prediction, can be used to probe the recognition of a class of fungal effectors by a family of WAKs.

Collectively, these findings extend our understanding of WAKs as genuine immune receptors that can recognise pathogen effectors, and can enable future efforts to restore and broaden resistance against fungal diseases in these two globally important crops.

BIOGRAPHY

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Nuren Tasneem is a PhD candidate in the Williams and Solomon groups at the Research School of Biology, Australian National University, studying plant immunity at the cell surface. Her research combines techniques in structural biology and protein biophysics together with in planta assays to uncover how fungal pathogens escape immune recognition. Throughout her PhD, Nuren has had the opportunity to collaborate with and learn from beamline scientists at the Australian Synchrotron, supported by the AINSE Postgraduate Research Award. In 2024, Nuren received a Maslen Scholarship to attend the SCANZ Crystallography School and was one of 20 participants nationally selected for the Australian Synchrotron's Small-Angle Scattering Workshop in 2025. Nuren's PhD is supported by the ANU International Research Scholarship and a GRDC top-up scholarship. Prior to starting a PhD, Nuren worked as a Synthetic Biologist at Nourish Ingredients, and as a Research Officer in the Williams–Jones labs at ANU. Alongside her PhD, she has also worked as a Technical Officer at the RSB-RSC Joint Mass Spectrometry Facility.