Wheat-Rhizobacteria-Pathogen Interaction Study

Wheat cultivar Alpowa, susceptible to soilborne fungal pathogen R. solani AG8, was used in this study. All wheat seeds were derived from the same seed source to reduce plant variation. Seeds were treated with 5% sodium hypochlorite for 3 min for surface disinfestation and rinsed three times with sterilized double-distilled water (ddH₂O) before germination. All wheat plants were grown in a greenhouse in 16/8 h light/darkness at 16°C. Arabidopsis thaliana Col-0 accession (hereafter Arabidopsis) was used to evaluate the influence of bacteria on root growth. The soil used in this study was collected from the Washington State University Dryland Research Station near Lind (47°0’N, 118°34’W), WA, United States, as described previously (Yin et al., 2021 (link)). The fungal pathogen R. solani AG8 was used and grown in potato dextrose agar medium (PDA, Sigma-Aldrich, St. Louise, MO) at 25°C. The inoculum of R. solani AG8 was prepared with twice-autoclaved millet seeds, as described previously (Yin et al., 2021 (link)). The bacterial strains isolated from the wheat rhizosphere (Yin et al., 2013 (link), 2021 (link)) were grown on 1/4 x tryptic soy agar/1 x tryptic soy broth (TSA/TSB, BD, Franklin Lakes, NJ) at 25°C.