title: Population densities of indigenous Acidobacteria change in the presence of plant growth promoting rhizobacteria (PGPR) in rhizosphere.
abstract: Rhizosphere microbial community has diverse metabolic capabilities and plays a crucial role in maintaining plant health. Oligotrophic plant growth promoting rhizobacteria (PGPR), along with difficult-to-culture microbial fractions, might be involved synergistically in microbe-microbe and plant-microbe interactions in the rhizosphere. Among the difficult-to-culture microbial fractions, Acidobacteria constitutes the most dominant phylum thriving in rhizospheric soils. We selected effective PGPR for tomato and black gram and studied their effect on population densities of acidobacterial members. Three facultatively oligotrophic PGPR were identified through 16S rRNA gene sequencing as Sphingobacterium sp. (P3), Variovorax sp. (P4), and Roseomonas sp. (A2); the latter being a new report of PGPR. In presence of selected PGPR strains, the changes in population densities of Acidobacteria were monitored in metagenomic DNA extracted from bulk and rhizospheric soils of tomato and black gram using real time qPCR. A gradual increase in equivalent cell numbers of Acidobacteria members was observed over time along with a simultaneous increase in plant growth promotion by test PGPR. We report characterization of three effective PGPR strains and their effects on indigenous, underexplored difficult-to-culture phylum-Acidobacteria. We suggest that putative interactions between these two bacterial groups thriving in rhizospheric soils could be beneficial for plant growth.
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India.
authors.forename: Sadaf
authors.initials: S
authors.lastname: Kalam
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India.
authors.forename: Subha Narayan
authors.initials: SN
authors.lastname: Das
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India.
authors.forename: Anirban
authors.initials: A
authors.lastname: Basu
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India.
authors.forename: Appa Rao
authors.identifier: http://orcid.org/0000-0003-3208-765X
authors.initials: AR
authors.lastname: Podile
mesh_terms: D061271:Acidobacteria / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D018556:Crops, Agricultural / Q000254:growth & development / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D016680:Genome, Bacterial; D018551:Solanum lycopersicum / Q000254:growth & development / Q000382:microbiology*; D056186:Metagenomics; D010802:Phylogeny; D063245:Plant Development; D018517:Plant Roots / Q000382:microbiology; D010944:Plants / Q000378:metabolism / Q000382:microbiology; D011156:Population Density; D058441:Rhizosphere; D012639:Seeds / Q000254:growth & development / Q000382:microbiology; D012988:Soil Microbiology; D000070658:Vigna / Q000254:growth & development / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial
keywords: Acidobacteria; metagenomics; plant growth promoting rhizobacteria; real time qPCR