The Making of Plant Armor: The Periderm

Léon Hirth seminar room - 9.15 am

Prof. Laura RAGNI, Institute of Biology, University of Freiburg, Germany, hosted by H. Renault

Protective barriers isolate the root from the environment, controlling water loss, gas exchanges, nutrient uptake, and preventing pathogen penetration, and thus represent an untapped resource to improve plant resilience. The periderm is the dynamic multilayer barrier, which covers the root during radial growth. It encompasses a stem cell niche that divides bifacially and produces cork layers toward the environment and the phelloderm toward the vasculature. Suberin and lignin deposition in the cork cell wall confers protective properties, and plants that lack these polymers are more susceptible to abiotic and biotic stresses. Despite the importance of the periderm, only recently have the mechanisms underlying periderm ontogenesis and cork differentiation started to be investigated.
In my team, using the Arabidopsis root as a model, we showed that auxin is required for cork cambium initiation and maintenance and elucidated the first cork cambium and cork differentiation regulatory network. This talk presents our current understanding of how stem cells of the cork cambium acquire their identity and how stem cell derivatives differentiate into highly suberized and lignified cork cells, with the goal of designing and building a protective barrier that enhances plant resilience in response to a changing environment.