Plant roots integrate environmental signals with development using exquisite spatiotemporal control. This is apparent in the deposition of suberin, an apoplastic diffusion barrier, which regulates flow of water, solutes and gases, and is environmentally plastic. Suberin is considered a hallmark of endodermal differentiation but is absent in the tomato endodermis. Instead, suberin is present in the exodermis, a cell type that is absent in the model organism Arabidopsis thaliana. Here we demonstrate that the suberin regulatory network has the same parts driving suberin production in the tomato exodermis and the Arabidopsis endodermis. Despite this co-option of network components, the network has undergone rewiring to drive distinct spatial expression and with distinct contributions of specific genes. Functional genetic analyses of the tomato MYB92 transcription factor and ASFT enzyme demonstrate the importance of exodermal suberin for a plant water-deficit response and that the exodermal barrier serves an equivalent function to that of the endodermis and can act in its place.

植物根系使用精妙的时空控制将环境信号与发展相结合。这在软木脂的沉积中很明显，软木脂是一种质外体扩散屏障，可调节水、溶质和气体的流动，并且具有环境可塑性。软木脂蛋白被认为是内胚层分化的标志，但在番茄内皮中不存在。相反，软木脂存在于外皮中，这是一种在模式生物拟南芥中不存在的细胞类型。在这里，我们证明软木脂调节网络具有驱动番茄外皮和拟南芥内皮中软木脂产生的相同部分。尽管网络组件存在这种共同选择，但网络已经经历了重新布线，以驱动不同的空间表达，并具有不同的特定基因贡献。番茄 MYB92 转录因子和 ASFT 酶的功能遗传分析表明，外皮软木脂蛋白对植物缺水反应的重要性，并且外皮屏障的功能与内皮相同，并且可以在其位置发挥作用。