title: In-planta sporulation phenotype: a major life history trait to understand the evolution of Alnus-infective Frankia strains.
abstract: Two major types of Frankia strains are usually recognized, based on the ability to sporulate in-planta: spore-positive (Sp+) and spore-negative (Sp-). We carried out a study of Sp+ and Sp- Frankia strains based on nodules collected on Alnus glutinosa, Alnus incana and Alnus viridis. The nodules were phenotyped using improved histology methods, and endophytic Frankia strain genotype was determined using a multilocus sequence analysis approach. An additional sampling was done to assess the relation between Sp+ phenotype frequency and genetic diversity of Frankia strains at the alder stand scale. Our results revealed that (i) Sp+ and Sp- Alnus-infective Frankia strains are genetically different even when sampled from the same alder stand and the same host-plant species; (ii) there are at least two distinct phylogenetic lineages of Sp+ Frankia that cluster according to the host-plant species and without regard of geographic distance and (iii) genetic diversity of Sp+ strains is very low at the alder stand scale compared with Sp- strains. Difference in evolutionary history and genetic diversity between Sp+ and Sp- Frankia allows us to discuss the possible ecological role of in-planta sporulation.
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.|Laboratoire de Biométrie et de Biologie Evolutive, CNRS, UMR 5558, Villeurbanne, F-69622, France.
authors.forename: Adrien C
authors.identifier: http://orcid.org/0000-0001-6765-4293
authors.initials: AC
authors.lastname: Pozzi
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.
authors.forename: Hector H
authors.initials: HH
authors.lastname: Bautista-Guerrero
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.|Laboratoire Microorganismes et Biomolécules Actives, Université de Tunis El Manar (FST), Tunis, 2092, Tunisia.
authors.forename: Imen
authors.initials: I
authors.lastname: Nouioui
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.
authors.forename: Laëtitia
authors.initials: L
authors.lastname: Cotin-Galvan
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Pepin
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Fournier
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Laboratoire de Biométrie et de Biologie Evolutive, CNRS, UMR 5558, Villeurbanne, F-69622, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Menu
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Fernandez
authors.affiliation: PRES Université de Lyon, Lyon, F-69361, France.|Université Lyon 1, Villeurbanne, F-69622, France.|Ecologie Microbienne, CNRS, UMR 5557, Villeurbanne, F-69622, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Herrera-Belaroussi
mesh_terms: D029661:Alnus / Q000382:microbiology*; D040161:Frankia / Q000145:classification* / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D058885:Multilocus Sequence Typing; D010641:Phenotype; D010802:Phylogeny; D053204:Root Nodules, Plant / Q000382:microbiology; D012988:Soil Microbiology; D013171:Spores, Bacterial / Q000235:genetics*