IntroductionAuxin estimation in plant tissues is a crucial component of auxin signaling studies. Despite the availability of various high‐throughput auxin quantification methods like LC‐MS, GC‐MS, HPLC, biosensors, and DR5‐gus/gfp‐based assays, auxin quantification remains troublesome because these techniques are very expensive and technology intensive and they mostly involve elaborate sample preparation or require the development of transgenic plants.ObjectivesTo find a solution to these problems, we made use of an old auxin detection system to quantify microbe derived auxins and modified it to effectively measure auxin levels in rice plants.Materials and methodsAuxins from different tissues of rice plants, including root samples of seedlings exposed to IAA/TIBA or subjected to different abiotic stresses, were extracted in ethanol. The total auxin level was measured by the presently described colorimetric assay and counterchecked by other auxin estimation methods like LC‐MS or gus staining of DR5‐gus overexpressing lines.ResultsThe presented colorimetric method could measure (1) the auxin levels in different tissues of rice plants, thus identifying the regions of higher auxin abundance, (2) the differential accumulation of auxins in rice roots when auxin or its transport inhibitor was supplied exogenously, and (3) the levels of auxin in roots of rice seedlings subjected to various abiotic stresses. The thus obtained auxin levels correlated well with the auxin levels determined by other methods like LC‐MS or gus staining and the expression pattern of auxin biosynthesis pathway genes.ConclusionsThe auxin estimation method described here is simple, rapid, cost‐effective, and sensitive and allows for the efficient detection of relative auxin abundances in plant tissues.

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一种快速、稳健的比色方法，用于测量植物组织中生长素的相对丰度

简介植物组织中生长素的估计是生长素信号研究的重要组成部分。尽管有各种高通量生长素定量方法，如 LC-MS、GC-MS、HPLC、生物传感器和 DR5-格斯/gfp基于分析的方法，生长素定量仍然很麻烦，因为这些技术非常昂贵且技术密集，而且它们大多涉及复杂的样品制备或需要开发转基因植物。目的为了找到这些问题的解决方案，我们利用旧的生长素检测系统量化微生物来源的生长素并对其进行修饰，以有效测量水稻植物中的生长素水平。材料和方法从水稻植物的不同组织中提取生长素，包括暴露于 IAA/TIBA 或遭受不同非生物胁迫的幼苗的根样品，在乙醇中提取。总生长素水平通过目前描述的比色测定法测量，并通过其他生长素估计方法（如 LC-MS 或 DR5-gus 染色）进行复核。格斯结果所提出的比色法可以测量（1）水稻植株不同组织中的生长素水平，从而识别生长素丰度较高的区域，（2）当提供生长素或其转运抑制剂时，水稻根部生长素的差异积累外源性；（3）遭受各种非生物胁迫的水稻幼苗根部生长素的水平。由此获得的生长素水平与其他方法（如 LC-MS 或 gus 染色）测定的生长素水平以及生长素生物合成途径基因的表达模式具有良好的相关性。结论本文描述的生长素估计方法简单、快速、经济有效、灵敏且易于使用。允许有效检测植物组织中的相对生长素丰度。