caa a22 4500 606209611 CHVBK 20210128101029.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00425-014-2206-z doi (NATIONALLICENCE)springer-10.1007/s00425-014-2206-z Quantitative evaluation of IAA conjugate pools in Arabidopsis thaliana [Elektronische Daten] [Peng Yu, Paula Lor, Jutta Ludwig-Müller, Adrian Hegeman, Jerry Cohen] Main conclusion : This work has demonstrated that the major method of estimating the amount of unknown IAA conjugates—base hydrolysis—can be significantly complicated by chemical artifacts such as glucobrassicin or protein degradation. The concept of ‘bound auxin' traces its origin back to more than 80years ago and has driven research on the sources and forms of these plant hormones since. Indeed, analytical studies have demonstrated that the majority of cellular auxin is conjugated to simple sugars, cyclitols, glycans, amino acids, and other biomolecules. A number of studies have confirmed the enzymatic systems responsible for the synthesis and hydrolysis of a number of such conjugates in Arabidopsis thaliana and some of these compounds have been identified in situ. However, the amount of indole-3-acetic acid (IAA) released upon treating Arabidopsis tissue extracts with base, a commonly employed technique for estimating the amount of IAA conjugates, greatly exceeded the summation of all the IAA conjugates known individually to be present in Arabidopsis. This discrepancy has remained as an unsolved question. In this study, however, we found that a significant portion of the IAA found after base treatment could be attributed to chemical conversions other than conjugate hydrolysis. Specifically, we showed that glucobrassicin conversion, previously thought to occur at insignificant levels, actually accounted for the majority of solvent soluble IAA released and that proteinaceous tryptophan degradation accounted for a large portion of solvent insoluble IAA. These studies clearly demonstrated the limits associated with using a harsh technique like base hydrolysis in determining IAA conjugates and support using more direct approaches such as mass spectrometry-based strategies for unambiguous characterizations of the total complement of IAA conjugates in new plant materials under study. Springer-Verlag Berlin Heidelberg, 2014 Alkaline hydrolysis nationallicence Auxin conjugates nationallicence Glucobrassicin nationallicence Mass Spectrometry nationallicence Selective hydrolysis nationallicence 4-Cl-IAA : 4-Chloro-indole-3-acetic acid nationallicence CV : Column volumes nationallicence DTT : Dithiothreitol nationallicence HEPES : 2-[4-(2-Hydroxyethyl)piperazin-1-yl]ethanesulfonic acid nationallicence IAA : Indole-3-acetic acid nationallicence IAN : Indole-3-acetonitrile nationallicence IA-Ala : Indole-3-acetyl alanine nationallicence IA-Asp : Indole-3-acetyl aspartate nationallicence IA-Glu : Indole-3-acetyl glutamate nationallicence IA-Leu : Indole-3-acetyl leucine nationallicence IA-Trp : Indole-3-acetyl tryptophan nationallicence MES : 2-(N-Morpholino)ethanesulfonic acid nationallicence OxIAA : Oxindole-3-acetic acid nationallicence TCA : Trichloroacetic acid nationallicence TFA : Trifluoroacetic acid nationallicence Yu Peng Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut Lor Paula Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut Ludwig-Müller Jutta Institut für Botanik, Technische Universität Dresden, 01062, Dresden, Germany aut Hegeman Adrian Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut Cohen Jerry Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut Planta Springer Berlin Heidelberg 241/2(2015-02-01), 539-548 0032-0935 241:2<539 2015 241 425 https://doi.org/10.1007/s00425-014-2206-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 brief-communication jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00425-014-2206-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yu Peng Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut NATIONALLICENCE 700 1- Lor Paula Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut NATIONALLICENCE 700 1- Ludwig-Müller Jutta Institut für Botanik, Technische Universität Dresden, 01062, Dresden, Germany aut NATIONALLICENCE 700 1- Hegeman Adrian Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut NATIONALLICENCE 700 1- Cohen Jerry Department of Horticultural Science, Microbial and Plant Genomics Institute, University of Minnesota, 1970 Folwell Avenue, 55108, Saint Paul, MN, USA aut NATIONALLICENCE 773 0- Planta Springer Berlin Heidelberg 241/2(2015-02-01), 539-548 0032-0935 241:2<539 2015 241 425