Beneficial microbial species and metabolites alleviate soybean oxidative damage and increase grain yield during short dry spells

Short dry spells are an important grain yield constraint in tropical regions. Plant growth-promoting bacteria (PGPB) and their metabolites can mitigate the impact of drought stress by promoting changes plant metabolism, physiology, biochemistry. However, effects PGPB on soybean [Glycine max (L.) Merril] under regions have not been established. The experiments were carried out field conditions with short spells. Therefore, this study we used a three-factorial trial to evaluate bacterial consortium consisting N2-fixing Bradyrhizobium japonicum (strain SEMIA 5079) diazoefficiens 5080), biocontrol agent Bacillus subtilis QST 713), Azospirillum brasilense (strains Ab-V5 Ab-V6) or without application microbial secondary (MSM, rhizobial enriched lipo-chitooligosaccharides (LCOs)) during two growing seasons. Photosynthetic pigments, gas exchange parameters, antioxidant enzyme activity proline concentrations leaves, nodulation, growth development evaluated. comprising spp., A. strains MSM increased contents chlorophyll (14.5 %), b (30.8 total (17.2 carotenoids (27.3 %) compared spp. treatment alone. This also net photosynthetic rate (17.7 stomatal conductance (56.5 internal CO2 concentration substomatal chamber (8.3 transpiration (44 plants that received standard inoculation (Bradyrhizobium only), while reducing leaf hydrogen peroxide (?18.8 (?29.4 lipid peroxidation (?15.9 activities superoxide dismutase (?18.2 catalase (?21.2 ascorbate peroxidase (?19.1 %). Taken together, results indicate beneficial combined alleviate oxidative damage Furthermore, improved development, up 12.2 %.