title: Characterization of Pythium oligandrum populations that colonize the rhizosphere of vines from the Bordeaux region.
abstract: This study focused on one oomycete, Pythium oligandrum, well-known for its plant protection abilities, which thrives in microbial environment where bacteria and fungal communities are also present. The genetic structures and dynamics of fungal and bacterial communities were studied in three Bordeaux subregions with various types of soil, using single-strand conformation polymorphism. The structure of the fungal communities colonizing the rhizosphere of vines planted in sandy-stony soils was markedly different from that those planted in silty and sandy soils; such differences were not observed for bacteria. In our 2-year experiment, the roots of all the vine samples were also colonized by echinulated oospore Pythium species, with P. oligandrum predominating. Cytochrome oxidase I and tubulin gene sequencings showed that P. oligandrum strains clustered into three groups. Based on elicitin-like genes coding for proteins able to induce plant resistance, six populations were identified. However, none of these groups was assigned to a particular subregion of Bordeaux vineyards, suggesting that these factors do not shape the genetic structure of P. oligandrum populations. Results showed that different types of rootstock and weeding management both influence root colonization by P. oligandrum. These results should prove particularly useful in improving the management of potentially plant-protective microorganisms.
authors.affiliation: INRA, UMR1065 Santé et Agroécologie du Vignoble (SAVE), ISVV, Villenave d'Ornon, France; BIOVITIS, Saint Etienne de Chomeil, France; UMR CNRS 5254/IPREM-EEM, IBEAS, Université de Pau et des Pays de l'Adour, Pau, France.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gerbore
authors.forename: Jessica
authors.initials: J
authors.lastname: Vallance
authors.forename: Amira
authors.initials: A
authors.lastname: Yacoub
authors.forename: François
authors.initials: F
authors.lastname: Delmotte
authors.forename: Damien
authors.initials: D
authors.lastname: Grizard
authors.forename: Catherine
authors.initials: C
authors.lastname: Regnault-Roger
authors.forename: Patrice
authors.initials: P
authors.lastname: Rey
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D044822:Biodiversity; D002352:Carrier Proteins / Q000096:biosynthesis; D005602:France; D005656:Fungal Proteins / Q000096:biosynthesis; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D036341:Intercellular Signaling Peptides and Proteins; D018515:Plant Leaves / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D018807:Polymorphism, Single-Stranded Conformational; D011775:Pythium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D058441:Rhizosphere; D012988:Soil Microbiology; D027843:Vitis
chemical_list: D002352:Carrier Proteins; D005656:Fungal Proteins; D036341:Intercellular Signaling Peptides and Proteins; C415980:Oligandrin protein, Pythium oligandrum
keywords: bacterial communities; elicitin-like genes; fingerprinting method; fungal communities; powdery mildew; rhizosphere