Molecular and General Genetics MGG

, Volume 220, Issue 2, pp 234–239

A pleiotropic mutation results in cross-resistance to auxin, abscisic acid and paclobutrazol

  • Rémy Bitoun
  • Philippe Rousselin
  • Michel Caboche

DOI: 10.1007/BF00260487

Cite this article as:
Bitoun, R., Rousselin, P. & Caboche, M. Molec. Gen. Genet. (1990) 220: 234. doi:10.1007/BF00260487


Mutant lines of Nicotiana plumbaginifolia resistant to the synthetic auxins 1-naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA) were isolated as germinating seedlings on selective medium. In each case, resistance was conferred by a single recessive nuclear mutation at one of 3 loci designated iba1, iba2 and iba3. Labelling studies with 14C NAA suggest that resistance was not due to changes in the uptake or metabolism of NAA. Plants homozygous for the iba1 mutation exhibit a syndrome of atypical germination and growth suggestive of a defect in the biosynthesis, metabolism or localization of abscisic acid. Wild-type seeds treated with gibberellin exhibit the same syndrome, including resistance to NAA and IBA. On the basis of these observations, we propose that auxin toxicity in seeds may be mediated by a block in gibberellin biosynthesis.

Key words

Mutagenized seeds Nicotiana plumbaginifolia Auxin-resistant mutants 



abscisic acid


gibberellic acid


indole-3-butyric acid


1-naphthaleneacetic acid


protoplast-derived cell


2,4-dichlorophenoxyacetic acid

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • Rémy Bitoun
    • 1
  • Philippe Rousselin
    • 1
  • Michel Caboche
    • 1
  1. 1.Laboratoire de Biologie CellulaireINRA Centre de VersaillesVersailles CedexFrance

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