o:3644 Production of Indolic Compounds by Rhizobial Bacteria en Abstract: Rhizobial bacteria, besides nitrogen fixation in symbiosis with legumes, can colonize the roots of non-legumes and promote their growth by different mechanisms, independently of N2 fixation. Owing to this, rhizobia are considered a plant growth-promoting rhizobacteria (PGPR). Some of the mechanisms of PGPR activity are phytohormone production. Selection of rhizobia which possess some of PGP traits in vitro is an important step prior to testing their effects on plants in controlled conditions or field. In this work the ability of indole-3-acid (IAA) production, one of the most important phytohormone of the auxin class, was evaluated in different rhizobial strains. The investigated rhizobial strains were isolated from alfalfa (belonged to the genera Ensifer and Rhizobium) and from soybean (Bradyrhizobium and Rhizobium). Strains of all investigated genera produced IAA in the presence of L-tryptophan as precursor, where Ensifer strains produced the highest amount of IAA (more than 200 μg ml-1), followed by Rhizobium, while Bradyrhizobium strains produced the least amount of IAA (with some exceptions up to 15 μg ml-1). With the increase of L-tryptophan concentration, the amount of IAA produced usually grew. Strains with high IAA production indicate their plant growth promoting potential and represent the candidates for evaluation of their effects in non-legumes in controlled and field conditions. rhizobia, phytohormones, inodole-3-acetic acid 1552099 10.5937/ZemBilj2302048M 2024-01-09T13:14:25.429Z 44 no 46 Milica Milićević 46 Dušica Delić Institute of Soil Science 0000-0002-0626-0482 46 Nataša Rasulić Institute of Soil Science 0000-0003-2807-0775 46 Mila Pešić Institute of Soil Science 0000-0001-7589-9100 46 Merisa Avdović Centro de Biotecnologıa y Genomica de Plantas (Universidad Politecnica de Madrid—Instituto Nacional de Investigacion y Tecnologıa Agraria y Alimentaria), Pozuelo de Alarcon, Spain 46 Olivera Stajković-Srbinović Institute of Soil Science 0000-0001-9759-843X 46 Biljana Nikolić University of Belgrade - Faculty of Biology, 11000 Belgrade, Serbia application/pdf 337467 https://unilib.phaidrabg.rs/o:3644 no yes 1 70 92000001 71A05 Zemljište i Biljka 48 59 2023