Date: 13th February 2019
Title: Cell-to-cell communication during plant immune responses
Location: Seminar room 1015, Biocentre 2, Viikinkaari 5
Host: Michael Wrzaczek
Abstract: The plant immune system is broadly characterised as a cell autonomous response system; in general, all plant cells are capable of pathogen perception and response. However, plasma membrane-lined pores that connect neighbouring cells called plasmodesmata are regulated during immune responses, identifying that cell-to-cell connectivity and communication is a component of immune signalling. Plasmodesmata close in response to a range of microbe associated molecular patterns (MAMPs), mediated by specialised immune signalling components located at plasmodesmata. For chitin, the LysM domain, GPI-anchored receptor protein LYM2 mediates plasmodesmal closure via complex formation with an additional LysM domain receptor kinase. Upon chitin binding, this receptor complex signals via calcium and reactive oxygen species signalling that ultimately triggers callose deposition and plasmodesmal closure. This is a rapid signalling event that occurs independently of other chitin-triggered responses that occur in the plasma membrane, identifying spatial resolution in receptor signalling cascades in plant cells. While plasma membrane located responses to chitin involve the same signalling molecules, the signalling cascade in the plasmodesmal membrane involves different mechanisms by which these molecules are produced. We are currently using a range of imaging and biochemical approaches to determine receptor complex and signalling dynamics in the plasmodesmal plasma membrane and how this underpins cell to cell connectivity and its contribution to both defence and infection.
Research in the Faulkner lab addresses how cell-to-cell communication in plants contributes to the initiation and execution of plant immune responses. Plant cells are connected to their neighbours via plasma membrane-lined pores called plasmodesmata, directly connecting the cytoplasm of neighbouring cells. In the Faulkner lab, we’ve observed that plasmodesmata dynamically respond (i.e. they open and close) when cells perceive a pathogen and we aim to determine how plasmodesmata respond to pathogen signals to trigger a functional change in their aperture. We also aim to determine how the connectivity between cells underpins the processes involved in immunity and infection.