Endophytic bacteria from selenium-supplemented wheat plants could be useful for plant-growth promotion, biofortification and Gaeumannomyces graminis biocontrol in wheat production

In this study, we isolated putative plant-growth-promoting endophytic bacteria from selenium-supplemented wheat grown under field conditions. These bacterial strains belonged to Bacillus, Paenibacillus, Klebsiella, and Acinetobacter genera and showed genetic similarly with rhizospheric bacteria isolated in the same Andisol soil and with other endophytic strains previously reported. Strains isolated from selenium-supplemented wheat were highly tolerant to elevated selenium concentration (ranged from 60 to 180 mM), and showed potential plant-growth-promoting capabilities (auxin and siderophore production, phytate mineralization, and tricalcium phosphate solubilization). In addition, some strains like Acinetobacter sp. (strain E6.2), Bacillus sp. (strain E8.1), Bacillus sp., and Klebsiella sp. (strains E5 and E1) inhibited the growth of Gaeumannomyces graminis mycelia in vitro at 100, 50, and 30 %, respectively. These endophytic microorganisms would be useful for dual purposes: selenium biofortification of wheat plants and control of G. graminis, the principal soil-borne pathogen in volcanic soils from southern Chile.