The periderm, similar to the vascular system, comprises three tissues: the phellogen/cork cambium (a post-embryonic meristem), whose stem cells differentiate on the inside into the phelloderm and outside into the phellem/cork. The barrier property of the periderm is conferred by the cork, which is lignified and suberized and thus impermeable. Cork chemistry has been mainly studied in potato and cork oak due to its economic relevance, impacting potato conservation/production and the quality of cork in its application as wine-stoppers and insulating/building materials. For instance, a variety of potato, resistant to common scab, displays more periderm layers and increased suberin deposition in the periderm. In spite of the economical and agronomical importance, the molecular networks underlying periderm establishment and cork differentiation during plant development and in responses to stresses are largely unknown.
Our goal is to shed light on the molecular mechanisms regulating periderm growth and cork differentiation in a changing environment. We aim to understand the molecular switch that triggers cork cambium initiation and how nutrient status, biotic and abiotic stress regulate this switch. We aim to elucidate the regulatory network underlying cork-suberin and cork-lignin depositions in standard and stress conditions and how cork cambium activity and vascular cambium activity are interconnected and modulated by the environment. In the long term, our research will pave the way for obtaining plants, which are resistant to heat, drought and pathogens and helps breeding programs for biomass/wood improvement.
The strength of our approach is that we have already developed a framework and a suite of tools (protocols for life imaging and whole root suberin pattern quantification, automated cell quantification software, reporter lines for each cell type at different developmental stages, rhizothrones to analyze roots grown on soil) to study periderm formation in the root of the amenable model plant Arabidopsis thaliana (Barbier de Reuille and Ragni 2017; Wunderling et al 2018; Campilho et al 2020; Serra et al. 2022). Thus, we can address fundamental questions of periderm growth, suberin genetics, physiology and biotic interactions using state of the art techniques, such as single cell sequencing and quantitative life imaging.