Figure 1

Effects of hfq mutation on lipA expression. (A) PCR confirmed hqf knockout. Lane 1: DNA markers. Lane 2: negative control (−). Lane 3, 4, 5, 6: mutant strains (PfΔhfq). Lane 7: Recombinant failed strains (B) Growth curve of Pseudomonas sp. Overnight bacterial cultures were performed in 50 mL LB. The initial OD value was adjusted to ~0.1. Bacterial cultures were shaken at 200 rpm at 28 °C, and OD value were determined once every 2 h. (C) qRT-PCR of relative lipA expression in P. protegens Pf-5 wild-type and the hfq mutant, and lipA mRNA levels were measured when bacterial growth reached the stationary phase. (D) Relative activity of whole-cell lipase in P. protegens Pf-5 wild-type and the hfq mutant. Whole-cell lipase activity was measured following bacterial culture in 50 mL LB to the stationary phase. (E) β-galactosidase activity in P. protegens Pf-5 wild-type and the hfq mutant. Bacteria were incubated in 50 mL LB to the stationary phase, and the enzyme activity of β-galactosidase was determined. Experiments were completed in triplicate. *P < 0.05, **P < 0.01 compared with the control group.