Project description:The periderm is basic for land plants due to its protective role during radial growth, which is achieved by the polymers deposited in the cell walls. Despite the research on the topic has unravelled the role of several enzymes and transcription factors, many questions remain open, especially those regarding cell development. Here we use the outer bark of cork oak (cork), holm oak (rhytidome), and their natural hybrids’ to further understand the mechanisms underlying periderm development. Cork is an outstanding model as it consists of a thick and very homogeneous periderm produced by a permanent mother-cell layer (phellogen). Conversely, holm oak contains a more heterogeneous bark including several thin periderms mixed with phloem, also known as a rhytidome. The inclusion of hybrid samples showing rhytidome-type and cork-type barks is valuable to approach cork development, allowing an accurate identification of candidate genes and processes. The present study underscores that biotic stress and cell death signalling are enhanced in rhytidome-type barks while lipid metabolism and cell cycle are enriched in cork-type barks. Based on the DEGs most expressed related to development, we highlight that cell division, cell expansion, and cell differentiation could account for the differences found between cork and rhytidome-type barks.
Project description:Cork quality is a technological trait of large interest for the Mediterranean cork industry. Our manuscript analyses the proteins and phenolics of cork producing cells in order to collect data about the molecular/biochemical pathways determining cork quality. To the best of our knowledge, this information is sparse in the research and technological community but it would be a valuable tool for breeding. We show that cells leading to the production stoppable (highly valued) and non-stoppable cork have contrasting profiles regarding soluble and cell-wall bound phenolics. The difference was also observed when considering the protein profiles but the discrimination between cork quality groups is not as remarkable as when considering phenolics. In any case, the mitochondrial metabolism points out for higher energy demand in non-stoppable cork producing cells.
