Epidermal identity determination at the surface of plant roots

Objective

In multicellular organisms, cells acquire specialized functions by activating specific transcriptional programs (cell identities). Cell identity can be inherited from parental cells or acquired based on positional signals. What is the role of position in defining cell identity? In plants, the root tip provides a natural example of cell re-positioning: the outer cell layer (root cap) undergoes programmed cell death, uncovering cells from the underlying epidermal lineage, which become exposed at the organ surface. I identified a set of genes that are activated when epidermal lineage cells are positioned at the organ surface (surface-specific genes), potentially by mechanical signals (my preliminary data). Thus, I hypothesize that turgor-based mechanical signals regulate epidermal identity and development. To test this hypothesis, I will need to learn from the host lab expertise in the study of root-soil-water interactions and transcriptomics, and to combine it with my expertise in advanced image analysis techniques and biomechanics. I aim to identify novel surface-specific genes, the molecular mechanism controlling them and to study the effect of soil on epidermal development.