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.

中文翻译：

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胞间连丝调节器的生长素依赖性控制产生了调节侧根出现的负反馈回路。

侧根起源于主根深处的初始细胞，必须通过几个覆盖层出现。侧根的出现需要新原基 (LRP) 的生长，以配合及时分离上覆根细胞，这是由生长素激素协调的发育程序。在这里，我们报告说，在拟南芥根中，生长素控制 LRP 上覆细胞中胞间连丝调节剂 PDLP5 的时空表达，从而形成负反馈回路。PDLP5 的功能是通过胞间连丝限制信号在细胞间的移动，它由 LRP 上覆的细胞中的生长素以渐进方式诱导。PDLP5 定位于这些细胞中的胞间连丝，并对器官出现以及整体根分枝产生负面影响。我们提出一个模型，