背景回顾：Most plant roots have multiple cortex layers that make up the bulk of the organ and play key roles in physiology, such as flood tolerance and symbiosis. 

提出问题：However, little is known about the formation of cortical layers outside of the highly reduced anatomy of Arabidopsis. 

主要研究：Here, we used single-cell RNA sequencing to rapidly generate a cell-resolution map of the maize root, revealing an alternative configuration of the tissue formative transcription factor SHORT-ROOT (SHR) adjacent to an expanded cortex. 

结果1-SHR蛋白可移动：We show that maize SHR protein is hypermobile, moving at least eight cell layers into the cortex.

结果2-SHR高阶突变体：Higher-order SHR mutantsin both maize and Setaria have reduced numbers of cortical layers, showing that the SHR pathway controls expansion of cortical tissue to elaborate anatomical complexity.

 摘 要 

大多数植物的根具有多层皮层，形成了器官的主体，在植物生理方面发挥重要作用，比如洪涝抗性或者共生系统。但是，目前对于拟南芥高度简化的解剖学结构外，多层皮层的形成还所知甚少。本文中，作者利用单细胞转录组测序的方法快速构建了玉米根的单细胞转录图谱，揭示了邻近拓展皮层中组织形成性转录因子SHR的另一种。作者发现SHR蛋白具有高度的可移动性，至少越过了8个细胞层到达皮层。玉米和狗尾草中，高阶SHR突变体导致皮层数目明显减少，说明SHR途径控制着皮层组织的扩张，从而作用于根解剖学结构的复杂性。