Journal Article

Genetics of nodulation in Aeschynomene evenia uncovers mechanisms of the rhizobium–legume symbiosis

Delteil, Amandine, Hufnagel, Bárbara, Gressent, Frédéric, Libourel, Cyril, Valentin, Nicolas, Klopp, Christophe, Gully, Djamel, Villar, Irene, Cartieaux, Fabienne, Nouwen, Nico, Brottier, Laurent, Mournet, Pierre, Farmer, Andrew, Garsmeur, Olivier, Fontaine, Loïc, Guyonnet, Rémi, D’Hont, Angélique, Giraud, Eric, Pervent, Marjorie, Rivallan, Ronan, Martin, Guillaume, Quilbé, Johan, Leleux, Philippe, Chaintreuil, Clémence, Becana, Manuel, Dereeper, Alexis, Benichou, Thomas, Bourge, Mickaël, Arrighi, Jean-François, Fardoux, Joël, Droc, Gaëtan, Lamy, Léo

2021

Overview

Among legumes (Fabaceae) capable of nitrogen-fixing nodulation, several Aeschynomene spp. use a unique symbiotic process that is independent of Nod factors and infection threads. They are also distinctive in developing root and stem nodules with photosynthetic bradyrhizobia. Despite the significance of these symbiotic features, their understanding remains limited. To overcome such limitations, we conduct genetic studies of nodulation in Aeschynomene evenia , supported by the development of a genome sequence for A. evenia and transcriptomic resources for 10 additional Aeschynomene spp. Comparative analysis of symbiotic genes substantiates singular mechanisms in the early and late nodulation steps. A forward genetic screen also shows that AeCRK, coding a receptor-like kinase, and the symbiotic signaling genes AePOLLUX, AeCCamK, AeCYCLOPS, AeNSP2, and AeNIN are required to trigger both root and stem nodulation. This work demonstrates the utility of the A. evenia model and provides a cornerstone to unravel mechanisms underlying the rhizobium–legume symbiosis. The establishment of symbiotic interaction between Aeschynomene evenia and photosynthetic bradyrhizobia doesn’t involve the canonical Nod factors and infection threads. Here, the authors assemble the draft genome of A. evenia and identify a receptor-like kinase in mediating the symbiotic interaction.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 45/22 / 45/23 / 45/44 / 45/70 / 45/77 / 45/90 / 631/208/8 / 631/449/2491 / 631/449/2676/2678 / 96/31 / 96/95 / Aeschynomene / Aeschynomene evenia / Amino Acid Sequence / Biological Evolution / Botanics / Bradyrhizobium - growth & development / Comparative analysis / Ecology, environment / Fabaceae - classification / Fabaceae - genetics / Fabaceae - growth & development / Fabaceae - microbiology / Gene Expression Regulation, Plant / Gene Ontology / Genes / Genetic screening / Genetics / Genome, Plant / Genomes / High-Throughput Nucleotide Sequencing / Humanities and Social Sciences / Kinases / Legumes / Life Sciences / Molecular Sequence Annotation / multidisciplinary / Nitrogen fixation / Nitrogenation / Nod factors / Nodulation / Nodules / Nucleotide sequence / Photosynthesis / Photosynthesis - genetics / Phylogeny / Plant Proteins - genetics / Plant Proteins - metabolism / Plant Root Nodulation - genetics / Plant Roots - genetics / Plant Roots - growth & development / Plant Roots - microbiology / Plant Stems - genetics / Plant Stems - growth & development / Plant Stems - microbiology / Plants genetics / Receptors / Science / Science (multidisciplinary) / Signal Transduction / Stems / Symbiosis / Symbiosis - genetics / Transcriptome / Vegetal Biology