Regulatory molecular networks underpinning periderm development

• Applicant: Professorin Dr. Laura Ragni, Ph.D.
• Subject Area: Plant Cell and Developmental Biology
• Term: since 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 259156069

The periderm, as an armor, protects the plant vasculature from biotic and abiotic stresses. In many seed plants, it is formed from the meristematic cells of the cork cambium during the increase of girth of plant organs. Similarly, to the vascular cambium, the cork cambium is arranged as a cylinder of cells that divide bifacially and differentiate into cork cells toward the environment and into phelloderm cells toward the vasculature. We previously showed that the plant hormone auxin is required for the initiation and maintenance of the cork cambium in roots and that the transcription factors WOX4 and BP act downstream of auxin. Strikingly, auxin is also required for vascular cambium establishment and WOX4 and BP are known vascular cambium regulators, raising questions on how auxin specificity is achieved and whether stem cell identity differs among cambia. By employing genetic tools, which specifically hinder auxin signaling in the cork or vascular cambium in a transcriptomic experiment, we have identified new putative cork cambium specific and core cambial regulators. In the continuation of this project, exploiting resources in which the expression of these novel regulators can be augmented or reduced in a specific stem cell context, we aim to decipher the cork and vascular cambium regulatory networks and gain more insights into the integration/communication of the two cambia. At the same time, we address the molecular determinants of cork cambium identity by employing single cell transcriptome approaches. Finally, we seek to understand how the environment modulates cork and vascular cambium activities, which will pave the way to identify novel root traits for breeding programs aiming to improve plant resilience.

• DFG Programme: Research Grants