Date/Time
Date(s) - Wed 17 June
13:00
Plant diseases are an increasing threat to natural ecosystems worldwide, and Aotearoa New Zealand is no exception. Kauri dieback, caused by the soil-borne pathogen Phytophthora agathidicida, is devastating populations of the iconic kauri tree (Agathis australis), a species of immense ecological and cultural significance. Despite ongoing management efforts, long-term solutions require a deeper understanding of how this pathogen infects and overcomes its host.
Like many plant pathogens, Phytophthora species rely on specialised molecules known as effector proteins, molecular “weapons” that manipulate plant cells and suppress immune responses.
In this talk, Dr Mariana Tarallo will explore how these effectors contribute to infection, focusing on a key effector protein, PaRXLR40.
Using a combination of molecular and infection-based approaches, she found that PaRXLR40 acts as a broad suppressor of plant immune responses, enabling the pathogen to more effectively colonise its host. She also identified a plant protein target, ARIA, which is involved in hormone signalling pathways linked to plant defence. Interestingly, both the pathogen effector and its host target appear to enhance disease, suggesting that the pathogen hijacks existing plant processes to promote infection.
This work provides new insights into the molecular strategies used by P. agathidicida and highlights potential targets for future disease control. Understanding these key pathogen “weapons” is an important step towards developing long-term solutions to protect kauri.
About the presenter
Dr Mariana Tarallo is a postdoctoral research fellow at Lincoln University. Her research focuses on understanding how plants interact with microbes, from the molecular mechanisms pathogens use to suppress plant immunity to how plants perceive and respond to microbial signals. Her previous work, supported by Bioprotection Aotearoa, investigated effector proteins in the kauri dieback pathogen Phytophthora agathidicida, uncovering how these molecules promote infection by manipulating host processes. She is currently researching how plants perceive fungal volatile organic compounds and how these compounds influence plant growth and defence.
About Rangahau Rising Webinar Series
Rangahau Rising is a webinar series showcasing emerging researchers who are asking bold questions and exploring new directions in bioprotection. Each session features an early career researcher sharing their journey, ideas, and in-progress work across a range of bioprotection topics.