A biosensor for the direct visualization of auxin.
A biosensor for the direct visualization of auxin.
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DOI：
10.1038/s41586-021-03425-2
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发表时间：
2021-04
期刊：
影响因子：
64.8
通讯作者：
Jürgens G
中科院分区：
文献类型：
--
作者：
Herud-Sikimić O;Stiel AC;Kolb M;Shanmugaratnam S;Berendzen KW;Feldhaus C;Höcker B;Jürgens G
植物中最重要的调节小分子之一是吲哚-3-乙酸，也称为生长素。它的动态再分配在植物生命的几乎每个方面都起着重要作用，从细胞形状和分裂到器官发生以及对光和重力的反应。到目前为止，它还没有能够直接确定生长素的空间和时间分布在细胞的分辨率。相反，它是从涉及内源性生长素反应机制的不可逆过程的可视化中推断出来的;然而，这样的系统不能检测到瞬时变化。在这里，我们报告了一个基因编码的生物传感器的生长素分布的定量在体内可视化。该传感器基于大肠杆菌色氨酸阻遏物，其结合口袋被设计成对生长素具有特异性。生长素结合部分与选定的荧光蛋白的偶联使得能够使用荧光共振能量转移信号作为读出。与以前的系统不同，这种传感器能够直接监测植物中单个细胞和细胞隔室内生长素的快速吸收和清除。通过响应梯度空间分布沿着根轴和其扰动的运输通道，以及快速和可逆的重新分配的内源性生长素在重力矢量的变化，我们的传感器能够实时监测生长素浓度在（亚）细胞分辨率和它们的空间和时间的变化，在植物的生命周期。一种用于植物生长素分布定量可视化的遗传编码传感器，能够实时监测单个细胞和细胞隔室内的生长素吸收和清除。
One of the most important regulatory small molecules in plants is indole-3-acetic acid, also known as auxin. Its dynamic redistribution has an essential role in almost every aspect of plant life, ranging from cell shape and division to organogenesis and responses to light and gravity. So far, it has not been possible to directly determine the spatial and temporal distribution of auxin at a cellular resolution. Instead it is inferred from the visualization of irreversible processes that involve the endogenous auxin-response machinery; however, such a system cannot detect transient changes. Here we report a genetically encoded biosensor for the quantitative in vivo visualization of auxin distribution. The sensor is based on the Escherichia coli tryptophan repressor, the binding pocket of which is engineered to be specific to auxin. Coupling of the auxin-binding moiety with selected fluorescent proteins enables the use of a fluorescence resonance energy transfer signal as a readout. Unlike previous systems, this sensor enables direct monitoring of the rapid uptake and clearance of auxin by individual cells and within cell compartments in planta. By responding to the graded spatial distribution along the root axis and its perturbation by transport inhibitors—as well as the rapid and reversible redistribution of endogenous auxin in response to changes in gravity vectors—our sensor enables real-time monitoring of auxin concentrations at a (sub)cellular resolution and their spatial and temporal changes during the lifespan of a plant. A genetically encoded sensor for the quantitative visualization of auxin distribution in plants enables real-time monitoring of its uptake and clearance by individual cells and within cellular compartments.