MAX4 and RMS1 are orthologous dioxygenase-like genes that regulate shoot branching in Arabidopsis and pea

Karim Sorefan; Jon Booker; Karine Haurogné; Magali Goussot; Katherine Bainbridge; Eloise Foo; Steven Chatfield; Sally Ward; Christine Beveridge; Catherine Rameau; Ottoline Leyser

doi:10.1101/gad.256603

MAX4 and RMS1 are orthologous dioxygenase-like genes that regulate shoot branching in Arabidopsis and pea

¹Department of Biology, University of York, York, YO10 5YW, United Kingdom
²Station de Génétique et d'Amélioration des Plantes, INRA, Route de Saint-Cyr, F-78026 Versailles Cedex, France
³School of Life Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia

Abstract

Shoot branching is inhibited by auxin transported down the stem from the shoot apex. Auxin does not accumulate in inhibited buds and so must act indirectly. We show that mutations in the MAX4 gene of Arabidopsis result in increased and auxin-resistant bud growth. Increased branching in max4 shoots is restored to wild type by grafting to wild-type rootstocks, suggesting that MAX4 is required to produce a mobile branch-inhibiting signal, acting downstream of auxin. A similar role has been proposed for the pea gene, RMS1. Accordingly, MAX4 and RMS1 were found to encode orthologous, auxin-inducible members of the polyene dioxygenase family.

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Footnotes

Supplemental material is available at http://www.genesdev.org.
Corresponding author.
↵4 Present address: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
↵5 Present address: Department of Botany, University of Toronto, Toronto M5S 1A1, Canada
↵6 E-MAIL hmol1{at}york.ac.uk; FAX 44-1904-328682.
Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/gad.256603.
- Accepted March 20, 2003.
- Received December 6, 2002.
Cold Spring Harbor Laboratory Press