POS-WED-019

A calmodulin-like protein regulates FLG22-induced plasmodesmal closure and innate immune responses to bacteria

B Xu1,2, C Cheval3, A Laohavisit4, B Hocking1,2, D Chiasson2, K Shirasu4, C Faulkner3 and M Gilliham1,2

  1. ARC Centre of Excellence in Plant Energy Biology, Waite Research Institute, University of Adelaide, Glen Osmond, SA 5064 Australia
  2. School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, SA 5064 Australia
  3. John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
  4. RIKEN Plant Science Centre, Tsurumi-ku, Yokohama 230-0045, Japan

Plants sense microbial signatures via the activation of pattern recognition receptors (PPRs), which triggers a range of cellular defences. One response is the closure of plasmodesmata, which reduces symplastic connectivity and the capacity for direct molecular exchange between host cells. Plasmodesmal flux is regulated by a variety of environmental cues but the downstream signalling pathways are poorly defined, especially how cytoplasmic calcium regulates plasmodesmal closure. Here, we identify that flg22-induced closure of plasmodesmata is mediated by a plasmodesmal-localised, Ca2+-binding protein Calmodulin-like 41 (CML41). CML41 mediates rapid callose deposition at plasmodesmata following flg22 treatment in a calcium-dependent manner, independently of other defence responses triggered by flg22 perception. CML41 transcriptionally responds to flg22 and is essential for full defence against Pseudomonas syringae.