近日，美国杜克大学Philip N. Benfey、斯坦福大学José R. Dinneny等研究人员合作发现，一种植物脂质运载蛋白促进视黄醛介导的振荡侧根起始。这一研究成果发表在2021年8月26日出版的国际学术期刊《科学》上。

为了确定类视黄醇是否调节根时钟，研究人员使用了视黄醛结合蛋白的化学报告基因。研究人员发现，视黄醛的结合先于根时钟，并预测了侧根器官发生的部位。视黄醛的应用增加了根时钟的震荡，并促进了侧根的形成。

一个与脊椎动物视黄醛结合蛋白同源的拟南芥蛋白TIL（TEMPERATURE INDUCED LIPOCALIN）的表达在视黄醛与报告蛋白结合的区域内振荡，并在异源系统中赋予视黄醛结合活性，当发生突变时，会降低视黄醛感性。这些结果证明了视黄醛和它的结合蛋白在侧根器官形成中的作用。

据了解，在拟南芥中，侧根的新器官形成是由一种叫做根时钟的振荡机制所决定的，它依赖于不明的代谢物。

附：英文原文

Title: A plant lipocalin promotes retinal-mediated oscillatory lateral root initiation

Author: Alexandra J. Dickinson, Jingyuan Zhang, Michael Luciano, Guy Wachsman, Evan Sandoval, Martin Schnermann, José R. Dinneny, Philip N. Benfey

Issue&Volume: 2021/08/26

Abstract: In Arabidopsis, de novo organogenesis of lateral roots is patterned by an oscillatory mechanism called the root clock, which is dependent on unidentified metabolites. To determine if retinoids regulate the root clock, we used a chemical reporter for retinaldehyde (retinal) binding proteins. We found that retinal binding precedes the root clock and predicts sites of lateral root organogenesis. Application of retinal increased root clock oscillations and promoted lateral root formation. Expression of an Arabidopsis protein with homology to vertebrate retinoid binding proteins, TEMPERATURE INDUCED LIPOCALIN (TIL) oscillates in the region of retinal binding to the reporter, confers retinal binding activity in a heterologous system, and when mutated, decreases retinal sensitivity. These results demonstrate a role for retinal and its binding partner in lateral root organogenesis.

DOI: 10.1126/science.abf7461

Source: https://science.sciencemag.org/content/early/2021/08/25/science.abf7461