Applied Microbiology and Biotechnology, Vol.104, No.17, 7467-7481, 2020
Surfactin and fengycin B extracted fromBacillus pumilusW-7 provide protection against potato late blight via distinct and synergistic mechanisms
Potato late blight caused byPhytophthora infestansis one of the most serious plant diseases worldwide. Cyclic lipopeptides (CLPs) extracted fromBacillusstrains exhibit a promising effect in the biocontrol of a variety of phytopathogens. However, the specific inhibitory effects and underlying mechanisms of CLPs againstP. infestansare poorly understood. In this study, we showed thatBacillus pumilusW-7 can inhibit the growth ofP. infestansmycelium. Two metabolites from W-7, surfactin and fengycin B, were identified using MS/MS. Fengycin B inhibited mycelium growth by inducing mycelium deformations, oxidative damage, and mitochondrial dysfunction. Surfactin induced potato plant defense responses by increasing the expression of the biocontrol genes (pod,pal, andcat) and their enzyme activities (POD, PAL, and CAT). Also, surfactin and fengycin B could exhibit a synergistic inhibitory effect onP. infestans. Taken together, our findings indicate thatB. pumilusW-7 and its CLPs are potential environmentally friendly and effective biocontrol agents for the preservation of potato crops.