Regulatory molecular networks underpinning periderm development

外周，作为一种盔甲，保护植物的脉管系统免受生物和非生物的胁迫。在许多种子植物中，它是在植物器官周长增加的过程中由软木形成层的分生细胞形成的。与维管形成层类似，软木形成层被排列成一个圆柱形的细胞，它们双向分裂，向环境方向分化为软木细胞，向脉管系统方向分化为木栓层细胞。我们之前的研究表明，植物激素生长素是根中软木形成层的形成和维持所必需的，而转录因子WOX4和BP在生长素的下游起作用。值得注意的是，生长素也是维管形成层建立所必需的，WOX4和BP是已知的维管形成层调节剂，这就提出了生长素特异性是如何实现的以及干细胞身份在形成层之间是否存在差异的问题。通过利用基因工具，在转录组学实验中特异性地阻碍软木或维管形成层中的生长素信号传导，我们已经确定了新的假定的软木形成层特异性和核心形成层调节剂。在该项目的后续研究中，我们将利用这些新调控因子的表达在特定干细胞环境下可以增强或减少的资源，破译软木和维管形成层调控网络，并对这两种形成层的整合/通信有更多的了解。同时，我们通过采用单细胞转录组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，这将为识别新的根系性状铺平道路，以提高植物的恢复力。

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.