Polly Bridges

PhD thesis: Requirement of plant and fungal N-acetylglucosamine transporters in arbuscular mycorrhizal symbiosis

The mutualistic arbuscular mycorrhizal symbiosis (AMS) is the oldest and most widespread plant-microbe interaction. Establishment of AMS requires a complex molecular dialogue between the host plant and fungus, allowing the two partners to recognise each other. It has been discovered that a rice N-acetylglucosamine (GlcNAc) transporter, known as NOPE1, is essential for this process, with nope1 mutants being severely impacted in AM colonisation and producing root exudates that do not elicit a symbiotic response in the fungus. Interestingly, the model AM fungus Rhizophagus irregularis also possesses an N-acetylglucosamine transporter, NGT1, which is upregulated upon AM colonisation. My project addresses the hypothesis that these two transporters work together in plant-fungal communication. I aim to determine whether NGT1 is needed for AM symbiosis, identify the bioactive molecule(s) transported by NOPE1/NGT1 and the direction of transport, and examine whether the spatial localisation of these proteins is coordinated.

Who or what inspired you to pursue your research interests?

I have always been interested in both molecular biology and symbiotic interactions. When I first heard about arbuscular mycorrhizal symbiosis as an undergraduate student, I was fascinated, and wanted to pursue it as a research topic. Since then, I undertook a summer internship, third-year research project, and my MPhil under the guidance of Prof. Uta Paszkowski, who has been a fantastic scientific mentor. I am additionally really excited about the application of new technologies, such as single-cell/spatial transcriptomics, artificial intelligence, and advances in imaging to my field of plant-microbe interactions, and I hope to use them in my own research.