How do the connections between a cell and its neighbours control how a cell responds? (FAULKNER_J27DTP)

Plant cells are connected to their neighbours via ‘tubes’ called plasmodesmata, creating an interconnected cytoplasm that joins cells within and between tissues and organs. Many molecules use plasmodesmata to move freely between cells and it is critical for a plant to tightly control how open its plasmodesmata are to enable control over how far molecular information and resources can travel through tissues. Indeed, this control is important to how a plant responds to many different environmental and developmental changes, including immune responses when it is being invaded by a pathogen.

We, and others, have identified that plasmodesmata close when a cell perceives a pathogen, isolating that cell from its neighbours. We recently found that whether plasmodesmata are open or closed is related to immune-associated gene expression changes. This relationship illustrates a significant gap in our knowledge of how plants defend themselves against disease-causing pathogens. Further, we also recently discovered that immune-associated plasmodesmal closure depends on the amount of sugar the leaf is producing – leaves that are consuming rather than producing sugar don’t isolate their cells. We can manipulate whether a leaf is a sugar producer or consumer and so this allows new opportunity for us to investigate the relationship between plasmodesmal connectivity and gene expression.

This project will leverage these advances to investigate how plasmodesmal connectivity influences how cell response to pathogens. The student will take advantage of the extensive tools and resources available in the Faulkner lab to investigate plasmodesmal function and immune responses, and use these to generate new information and hypotheses to be tested. The project will use molecular biology, bioinformatics, genetics and quantitative imaging approaches to pioneer new understanding of how cell-to-cell connectivity via plasmodesmata underpins immune success in different leaves of a plant.