Screening of plant growth promoting bacteria associated with barley plants (Hordeum vulgare L.) cultivated in South Brazil

Abstract

The occurrence of associations between bacteria and plant roots may be beneficial, neutral or detrimental. Plant growth promoting (PGP) bacteria form a heterogeneous group of beneficial microorganisms that can be found in the rhizosphere, the root surfaces or in association with host plant. The aim of this study was to isolate and characterize PGP bacteria associated to barley plants (Hordeum vulgare L.) aiming a future application as agricultural inoculant. One hundred and sixty bacterial strains were isolated from roots or rhizospheric soil of barley based on their growth in nitrogen-free selective media. They were evaluated for their ability to produce indolic compounds (ICs) and siderophores, and to solubilize tricalcium phosphate in in vitro assays. Most of them (74%) were able to synthesize ICs in the presence of the precursor L-tryptophan, while 57% of the isolates produced siderophores in Fe-limited liquid medium, and 17% were able to solubilize tricalcium phosphate.

Isolation and characterization of bacteria associated with the rhizosphere of halophytes (Salsola stocksii and Atriplex amnicola) for production of hydrolytic enzymes

“…Bacterial isolates related to Kocuria and Streptomyces were identified from the rhizosphere of halophytes as well as from the non-rhizospheric soils. These bacteria have plant growth abilities like phosphate solubilization and can be used as biofertilizers [45,46]. Polaribacter strains identified in this study are polar marine bacteria having gas vacuoles.…”

Ecological Processes of Bacterial and Fungal Communities Associated with Typha orientalis Roots in Wetlands Were Distinct during Plant Development

“…Members of Burkholderia are important diazotrophs, and plant growth-promoting rhizobacteria (PGPR) ( 82 , 83 ) with nitrogen-fixing and phosphorus solubilizing abilities ( 84 , 85 ). These taxa have all been identified as important PGPR ( 86 , 87 ) that can promote and improve host adaptability and performance through activities such as indoleacetic acid (IAA) production, siderophore production, and induced systemic resistance ( 88 , 89 ). This finding was further supported by function prediction analysis of FAPROTAX, which indicated that function of chemoheterotrophy and aerobic chemoheterotrophy were significantly more abundant at earlier plant developmental stages to promote plant growth ( Fig.…”