Journal of Plant Growth Regulation

, Volume 29, Issue 2, pp 242–248

An Inhibitor of Tryptophan-Dependent Biosynthesis of Indole-3-Acetic Acid Alters Seedling Development in Arabidopsis

  • Jutta Ludwig-Müller
  • Kathrin Denk
  • Jerry D. Cohen
  • Marcel Quint
Article

DOI: 10.1007/s00344-009-9128-1

Cite this article as:
Ludwig-Müller, J., Denk, K., Cohen, J.D. et al. J Plant Growth Regul (2010) 29: 242. doi:10.1007/s00344-009-9128-1

Abstract

Although polar transport and the TIR1-dependent signaling pathway of the plant hormone auxin/indole-3-acetic acid (IAA) are well characterized, understanding of the biosynthetic pathway(s) leading to the production of IAA is still limited. Genetic dissection of IAA biosynthetic pathways has been complicated by the metabolic redundancy caused by the apparent existence of several parallel biosynthetic routes leading to IAA production. Valuable complementary tools for genetic as well as biochemical analysis of auxin biosynthesis would be molecular inhibitors capable of acting in vivo on specific or general components of the pathway(s), which unfortunately have been lacking. Several indole derivatives have been previously identified to inhibit tryptophan-dependent IAA biosynthesis in an in vitro system from maize endosperm. We examined the effect of one of them, 6-fluoroindole, on seedling development of Arabidopsis thaliana and tested its ability to inhibit IAA biosynthesis in feeding experiments in vivo. We demonstrated a correlation of severe developmental defects or growth retardation caused by 6-fluoroindole with significant downregulation of de novo synthesized IAA levels, derived from the stable isotope-labeled tryptophan pool, upon treatment. Hence, 6-fluoroindole shows important features of an inhibitor of tryptophan-dependent IAA biosynthesis both in vitro and in vivo and thus may find use as a promising molecular tool for the identification of novel components of the auxin biosynthetic pathway(s).

Keywords

Auxin biosynthesisInhibitorArabidopsis thalianaIndole-3-acetic acid6-Fluoroindole

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Jutta Ludwig-Müller
    • 1
  • Kathrin Denk
    • 2
  • Jerry D. Cohen
    • 3
  • Marcel Quint
    • 2
  1. 1.Institute of BotanyTechnische Universität DresdenDresdenGermany
  2. 2.Independent Junior Research Group, Leibniz Institute of Plant Biochemistry HalleHalleGermany
  3. 3.Department of Horticultural Science and the Microbial and Plant Genomics InstituteUniversity of MinnesotaSaint PaulUSA