Facile preparation of deuterium-labeled standards of indole-3-acetic acid (IAA) and its metabolites to quantitatively analyze the disposition of exogenous IAA in Arabidopsis thaliana

[2',2'-2 H-2]-indole-3-acetic acid ([2',2'-2 H-2]IAA) was prepared in an easy and efficient manner involving basecatalyzed hydrogen/deuterium exchange. 1-O-([2',2'-2 H-2]-indole-3-acetyl)-fl-D-glucopyranose, [2',2'-2 H-2]-2oxoindole-3-acetic acid, and 1-0-([2',2'-2 H-2]-2-oxoindole-3-acetyl)-p-D-glucopyranose were also successfully synthesized from deuterated 1AA, and effectively utilized as internal standards in the quantitative analysis of 1AA and its metabolites in Arabidopsis thaliana by using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ES1-MS/MS). The use of this technique shows that these metabolites were accumulated in the roots of Arabidopsis seedlings. Dynamic changes in the metabolites of IAA were observed in response to exogenous IAA, revealing that each metabolic action was regulated differently to contribute to the IAA homeostasis in Arabidopsis.