Journal Article

Inhibition of Auxin Signaling inFrankiaSpecies-Infected Cells inCasuarina glaucaNodules Leads to Increased Nodulation

Champion, Antony, Bonneau, Jocelyne, Crabos, Amandine, Lucas, Mikael, Moukouanga, Daniel, Cissoko, Maïmouna, Prodjinoto, Hermann, Hocher, Valérie, Gherbi, Hassen, Svistoonoff, Sergio, Diédhiou, Issa, Pirolles, Elodie, Vaissayre, Virginie, Tromas, Alexandre, Franche, Claudine, Laplaze, Laurent

2015

Overview

Actinorhizal symbioses are mutualistic interactions between plants and the soil bacteriaFrankiaspp. that lead to the formation of nitrogen-fixing root nodules. The plant hormone auxin has been suggested to play a role in the mechanisms that control the establishment of this symbiosis in the actinorhizal treeCasuarina glauca. Here, we analyzed the role of auxin signaling inFrankiaspp.-infected cells. Using a dominant-negative version of an endogenous auxin-signaling regulator, INDOLE-3-ACETIC ACID7, we established that inhibition of auxin signaling in these cells led to increased nodulation and, as a consequence, to higher nitrogen fixation per plant even if nitrogen fixation per nodule mass was similar to that in the wild type. Our results suggest that auxin signaling inFrankiaspp.-infected cells is involved in the long-distance regulation of nodulation in actinorhizal symbioses.

• Publisher: American Society of Plant Biologists
• Subject: Auxins / Frankia / Genes / Nitrogen fixation / Nodulation / Nodules / Plant cells / Plant roots / Plants / SIGNALING AND RESPONSE / Symbiosis