Root branching toward water involves posttranslational modification of transcription factor ARF7

First author: Beatriz Orosa-Puente; Affiliations: University of Durham (杜伦大学): Durham, UK

Corresponding author: Malcolm J. Bennett

Plants adapt to heterogeneous (各种各样的) soil conditions by altering their root architecture. For example, roots branch when in contact with water by using the hydropatterning response. We report that hydropatterning is dependent on auxin response factor ARF7. This transcription factor induces asymmetric expression of its target gene LBD16 in lateral root founder cells. This differential expression pattern is regulated by posttranslational modification of ARF7 with the small ubiquitin-like modifier (SUMO) protein. SUMOylation negatively regulates ARF7 DNA binding activity. ARF7 SUMOylation is required to recruit the Aux/IAA (indole-3-acetic acid) repressor protein IAA3. Blocking ARF7 SUMOylation disrupts IAA3 recruitment and hydropatterning. We conclude that SUMO-dependent regulation of auxin response controls root branching pattern in response to water availability.

植物通过改变其根系结构能够适应各种各样的土壤条件。比如，根系在与水接触时会通过hydropatterning响应进行分支。本文报道了hydropatterning主要依赖于生长素响应因子ARF7。该转录因子诱导其靶基因LBD16在侧根基细胞中的不对称表达。这种差异表达模式受到ARF7和小的类泛素修饰蛋白SUMO的翻译后修饰。类泛素化修饰负调控ARF7的DNA结合活性。ARF7的类泛素化修饰对于招募Aux/IAA抑制蛋白IAA3是必需的。阻断ARF7的类泛素化修饰会破坏IAA3的招募和hydropatterning。依赖于SUMO的生长素响应调控控制植物响应于可利用水分的根系分支模式。

p.s. Water availability is a potent regulator of plant development and induces root branching through a process termed hydropatterning. (水分供给是调控植物发育的重要因子，会通过一个叫hydropatterning的过程介导植物根的分支。)

通讯：Malcolm Bennett  (https://www.nottingham.ac.uk/biosciences/people/malcolm.bennett)

研究方向：控制植物根生长和发育的调控信号、基因及分子机制。

doi: 10.1126/science.aau3956

Journal: Science

Published date: 21 December, 2018