title: Beneficial Bacteria Isolated from Grapevine Inner Tissues Shape Arabidopsis thaliana Roots.
abstract: We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards.
authors.affiliation: Dipartimento di Biologia, Universita degli Studi di Padova, Padova, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Baldan
authors.affiliation: Dipartimento di Biologia, Universita degli Studi di Padova, Padova, Italy.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Nigris
authors.affiliation: Dipartimento di Biologia, Universita degli Studi di Padova, Padova, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Romualdi
authors.affiliation: Dipartimento di Biologia, Universita degli Studi di Padova, Padova, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: D'Alessandro
authors.affiliation: Dipartimento di Biologia, Universita degli Studi di Padova, Padova, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Clocchiatti
authors.affiliation: Dipartimento di Biologia, Universita degli Studi di Padova, Padova, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Zottini
authors.affiliation: Dipartimento DAFNAE - Department of Agronomy Food Natural Resources Animals and Environment, Legnaro (PD), Italy.
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Stevanato
authors.affiliation: Dipartimento DAFNAE - Department of Agronomy Food Natural Resources Animals and Environment, Legnaro (PD), Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Squartini
authors.affiliation: Dipartimento di Biologia, Universita degli Studi di Padova, Padova, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Baldan
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000382:microbiology; D001407:Bacillus / Q000254:growth & development / Q000302:isolation & purification; D008837:Micrococcus / Q000254:growth & development / Q000302:isolation & purification; D020636:Pantoea / Q000254:growth & development / Q000302:isolation & purification; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology; D027843:Vitis / Q000382:microbiology*