Auxin-dependent control of a plasmodesmal regulator creates a negative feedback loop modulating lateral root emergence

First author: Ross Sager; Affiliations:  University of Delaware (特拉华大学): Newark, USA

Corresponding author: Jung-Youn Lee 

Lateral roots originate from initial cells deep within the main root and must emerge through several overlying layers. Lateral root emergence requires the outgrowth of the new primordium (LRP) to coincide with the timely separation of overlying root cells, a developmental program coordinated by the hormone auxin. Here, we report that in Arabidopsis thaliana roots, auxin controls the spatiotemporal expression of the plasmodesmal regulator PDLP5 in cells overlying LRP, creating a negative feedback loop. PDLP5, which functions to restrict the cell-to-cell movement of signals via plasmodesmata, is induced by auxin in cells overlying LRP in a progressive manner. PDLP5 localizes to plasmodesmata in these cells and negatively impacts organ emergence as well as overall root branching. We present a model, incorporating the spatiotemporal expression of PDLP5 in LRP-overlying cells into known auxin-regulated LRP-overlying cell separation pathways, and speculate how PDLP5 may function to negatively regulate the lateral root emergence process.

植物的侧根起源于主根内部的原始细胞，侧根的起始必须贯通几个覆盖细胞层。侧根的出现需要新的原基向外生长，并且要与根外层细胞的剥离时间相吻合，该发育进程由植物激素生长素所协调。本文中，作者报道了在拟南芥的根中，生长素控制着胞间连丝调控因子PDLP5在覆盖在LRP上的细胞中的时空表达，形成了一个负反馈调节环。PDLP5显示通过胞间连丝的细胞间信号通讯，在覆盖在LRP上的细胞中由生长素循序渐进的诱导。PDLP5定位于这些细胞的胞间连丝中，负作用于器官发生和整体的根分枝。作者将PDLP5在覆盖在LRP上的细胞中的时空表达整合到已知的生长素调节覆盖在LRP上的细胞的分离通路中，并推测了PDLP5是如何作用于侧根形成的负调控的。

通讯：Jung-Youn Lee（https://www.udel.edu/academics/colleges/canr/departments/plant-and-soil-sciences/faculty-staff/jung-youn-lee/）

个人简介：佛罗里达大学，硕士；佛罗里达大学，博士；加州大学戴维斯分校，博士后。

研究方向：植物细胞间通讯的分子机制。

doi: https://doi.org/10.1038/s41467-019-14226-7

Journal: Nature Communications

Published date: January 17, 2020