From lateral root density to nodule number, the strigolactone analogue GR24 shapes the root architecture of Medicago truncatula

Loading...
Thumbnail Image

Authors

De Cuyper, Carolien
Fromentin, Justine
Yocgo, Rosita Endah
De Keyser, Annick
Guillotin, Bruno
Kunert, Karl J.
Boyer, François-Didier
Goormachtig, Sofie

Journal Title

Journal ISSN

Volume Title

Publisher

Oxford University Press

Abstract

In the rhizosphere, strigolactones not only act as crucial signalling molecules in the communication of plants with parasitic weeds and arbuscular mycorrhiza, but they also play a key role in regulating different aspects of the root system. Here we investigated how strigolactones influence the root architecture of Medicago truncatula. We provide evidence that addition of the synthetic strigolactone analogue GR24 has an inhibitory effect on the lateral root density. Moreover, treatment with GR24 of Sinorhizobium meliloti-inoculated M. truncatula plants affects the nodule number both positively and negatively, depending on the concentration. Plants treated with 0.1 μM GR24 had a slightly increased number of nodules, whereas concentrations of 2 and 5 μM strongly reduced it. This effect was independent of the autoregulation of nodulation mechanism that is controlled by SUPER NUMERIC NODULE. Furthermore, we demonstrate that GR24 controls the nodule number through crosstalk with SICKLE-dependent ethylene signalling. Additionally, because the expression of the nodulation marker EARLY NODULATION11 was strongly reduced in GR24-treated plants, we concluded that strigolactones influence nodulation at a very early stage of the symbiotic interaction.

Description

Keywords

ENOD11, Ethylene, GR24, Medicago truncatula, Nodulation, Root architecture

Sustainable Development Goals

Citation

De Cuyper, C, Fromentin, J, Yocgo, RE, De Keyser, A, Guillotin, B, Kunert, K, Boyer, FD & Goormachtig, S 2015, 'From lateral root density to nodule number, the strigolactone analogue GR24 shapes the root architecture of Medicago truncatula', Journal of Experimental Botany, vol. 66, no. 1, pp. 137-146.