bioRxiv preprint doi: https://doi.org/10.1101/789420; this version posted October 1, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Title Conifers exhibit a characteristic inactivation of auxin to maintain tissue homeostasis Authors Federica Brunoni1,2,a, Silvio Collani1, Rubén Casanova-Saéz2, Jan Šimura2, Michal Karady2,a, Markus Schmid1, Karin Ljung2,b and Catherine Bellini1,3,b 1 Umeå Plant Science Centre, Dept of Plant Physiology, Umeå University (Umu), Umeå, Sweden 2 Umeå Plant Science Centre, Dept of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden 3 Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech Versailles, France a Present address: Laboratory of Growth Regulators, Faculty of Science, Palacký University & Institute of Experimental Botany, The Czech Academy of Sciences, Šlechtitelů 27, CZ- 78371, Olomouc, Czech Republic b to whom correspondence may be addressed. Email:
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[email protected] Summary • Dynamic regulation of the levels of the natural auxin, indol-3-acetic acid (IAA), is essential to coordinate most of the physiological and developmental processes and responses to environmental changes. Oxidation of IAA is a major pathway to control auxin concentrations in Arabidopsis and, along with IAA conjugation, to respond to perturbation of IAA homeostasis. However, these regulatory mechanisms are still poorly investigated in conifers. To reduce this gap of knowledge, we investigated the different contribution of the IAA inactivation pathways in conifers. • Mass spectrometry-based quantification of IAA metabolites under steady state conditions and after perturbation was investigated to evaluate IAA homeostasis in bioRxiv preprint doi: https://doi.org/10.1101/789420; this version posted October 1, 2019.