背景回顾：Plant roots exhibit plasticity in their branching patterns to forage efficiently for heterogeneously distributed resources, such as soil water. The xerobranching response represses lateral root formation when roots lose contact with water. 

结果1-脱落酸响应：Here, we show that xerobranching is regulated by radial movement of the phloem-derived hormone abscisic acid, which disrupts intercellular communication between inner and outer cell layers through plasmodesmata. 

结果2-生长素移动：Closure of these intercellular pores disrupts the inward movement of the hormone signal auxin, blocking lateral root branching. 

结果3-复水：Once root tips regain contact with moisture, the abscisic acid response rapidly attenuates. 

结论：Our study reveals how roots adapt their branching pattern to heterogeneous soil water conditions by linking changes in hydraulic flux with dynamic hormone redistribution.

Dynamic hormone redistribution determines root branching or xerobranching response to external water availability.

植物的根在其分枝模式上存在极强的可塑性，从而能够在非均匀分布的可利用资源条件下高效获取土壤水分等物质。干分枝响应在根系面对缺水时，抑制侧根的形成。本文中，作者发现植物的干分枝响应受到来自于韧皮部植物激素脱落酸的径向移动控制，其通过胞间连丝扰乱内外层细胞间的通讯。这些细胞间孔的关闭阻碍了激素信号生长素的向内运输，从而阻断了侧根分枝形成。一旦根尖重新感知到湿度，脱落酸响应迅速减弱。本文的研究揭示了植物的根如何通过分枝模式快速响应非均匀分布的土壤水分条件，将外界环境的水流通量变化与植物体内的激素动态再分配联系到了一起。

** Malcolm Bennett **