title: Acidobacteria strains from subdivision 1 act as plant growth-promoting bacteria.
abstract: Acidobacteria is one of the most abundant phyla in soils and has been detected in rhizosphere mainly based on cultivation-independent approaches such as 16S rRNA gene survey. Although putative interaction of Acidobacteria with plants was suggested, so far no plant-bacterial interactions were shown. Therefore, we performed several in vitro tests to evaluate Acidobacteria-plant interactions and the possible mechanisms involved in such interaction. We observed that Arabidopsis thaliana inoculated with three strains belonging to Acidobacteria subdivision 1 showed increase in biomass of roots and shoots as well as morphological changes in root system. Our results indicate that the plant hormone indole-3-acetic acid production and iron acquisition are plausibly involved in the plant and Acidobacteria interactions. Here, we confirm for the first time that Acidobacteria can actively interact with plants and act as plant growth-promoting bacteria. In addition, we show that Acidobacteria strains produce exopolysaccharide which supports the adhesion of bacteria to the root surfaces.
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Kielak
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands.
authors.forename: Matheus A P
authors.initials: MA
authors.lastname: Cipriano
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands. e.kuramae@nioo.knaw.nl.
authors.forename: Eiko E
authors.initials: EE
authors.lastname: Kuramae
mesh_terms: D061271:Acidobacteria / Q000378:metabolism*; D017360:Arabidopsis / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology; D018533:Biomass; D007210:Indoleacetic Acids / Q000378:metabolism*; D063245:Plant Development; D018517:Plant Roots / Q000382:microbiology*; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D012987:Soil; D012988:Soil Microbiology; D013559:Symbiosis / Q000502:physiology
chemical_list: D007210:Indoleacetic Acids; D011135:Polysaccharides, Bacterial; D012336:RNA, Ribosomal, 16S; D012987:Soil; C030737:indoleacetic acid
keywords: Acidobacteria; Arabidopsis thaliana; IAA; PGPB; Root biomass