1. Université de Toulouse; UPS; CNRS; Surface Cellulaire et Signalisation chez les Végétaux, 24 chemin de Borde Rouge, F-31326 Castanet-Tolosan, France
2. Station de Génétique et d'Amélioration des Plantes, Institut J. P. Bourgin, UR254 INRA, F-78000 Versailles, France
3. ARC Centre of Excellence for Integrative Legume Research, The University of Queensland, Brisbane 4072, Australia
4. CNRS, UMR5504, INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, INSA de Toulouse, F-31400 Toulouse, France
5. Plant Research International, PO Box 16, 6700 AA Wageningen, the Netherlands
6. Laboratory of Plant Physiology, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, the Netherlands
7. School of Integrative Biology, The University of Queensland, Brisbane 4072, Australia
8. These authors contributed equally to this work.

Correspondence to: Guillaume Bécard¹Catherine Rameau^2,8 Correspondence and requests for materials should be addressed to C.R. (Email: rameau@versailles.inra.fr) or G.B. (Email: becard@scsv.ups-tlse.fr).

Abstract

A carotenoid-derived hormonal signal that inhibits shoot branching in plants has long escaped identification. Strigolactones are compounds thought to be derived from carotenoids and are known to trigger the germination of parasitic plant seeds and stimulate symbiotic fungi. Here we present evidence that carotenoid cleavage dioxygenase 8 shoot branching mutants of pea are strigolactone deficient and that strigolactone application restores the wild-type branching phenotype to ccd8 mutants. Moreover, we show that other branching mutants previously characterized as lacking a response to the branching inhibition signal also lack strigolactone response, and are not deficient in strigolactones. These responses are conserved in Arabidopsis. In agreement with the expected properties of the hormonal signal, exogenous strigolactone can be transported in shoots and act at low concentrations. We suggest that endogenous strigolactones or related compounds inhibit shoot branching in plants. Furthermore, ccd8 mutants demonstrate the diverse effects of strigolactones in shoot branching, mycorrhizal symbiosis and parasitic weed interaction.

1. Université de Toulouse; UPS; CNRS; Surface Cellulaire et Signalisation chez les Végétaux, 24 chemin de Borde Rouge, F-31326 Castanet-Tolosan, France
2. Station de Génétique et d'Amélioration des Plantes, Institut J. P. Bourgin, UR254 INRA, F-78000 Versailles, France
3. ARC Centre of Excellence for Integrative Legume Research, The University of Queensland, Brisbane 4072, Australia
4. CNRS, UMR5504, INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, INSA de Toulouse, F-31400 Toulouse, France
5. Plant Research International, PO Box 16, 6700 AA Wageningen, the Netherlands
6. Laboratory of Plant Physiology, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, the Netherlands
7. School of Integrative Biology, The University of Queensland, Brisbane 4072, Australia
8. These authors contributed equally to this work.

Correspondence to: Guillaume Bécard¹Catherine Rameau^2,8 Correspondence and requests for materials should be addressed to C.R. (Email: rameau@versailles.inra.fr) or G.B. (Email: becard@scsv.ups-tlse.fr).

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.