Regulatory molecular networks underpinning periderm development

周壁作为盔甲，保护植物维管系统免受生物和非生物胁迫。在许多种子植物中，它是由软木形成层的分生细胞在植物器官周长增加的过程中形成的。与维管形成层相似，软木形成层排列为细胞圆柱体，其两面分裂并朝向环境分化为软木细胞，朝向维管系统分化为外胚层细胞。我们以前表明，植物激素生长素是必需的软木形成层在根中的启动和维护和转录因子WOX 4和BP的生长素下游的行为。引人注目的是，生长素也需要维管形成层的建立和WOX 4和BP是已知的维管形成层调节剂，提出了生长素特异性是如何实现的问题，以及干细胞的身份是否在形成层中不同。通过采用遗传工具，特别是阻碍生长素信号在软木或维管形成层的转录实验，我们已经确定了新的推定软木形成层的具体和核心形成层的监管机构。在该项目的继续中，利用可以在特定干细胞背景下增加或减少这些新型调节因子表达的资源，我们的目标是破译软木和维管形成层调节网络，并获得对两种形成层整合/通讯的更多见解。与此同时，我们采用单细胞转录组的方法来解决软木形成层身份的分子决定因素。最后，我们试图了解环境如何调节软木和维管形成层的活动，这将铺平道路，以确定新的根性状的育种计划，旨在提高植物的韧性。

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.