Metabolites from a global regulator engineered strain of Pseudomonas lurida and their inducement of trap formation in Arthrobotrys oligospora

Background Plant parasitic nematodes (PPNs) cause serious harm to agricultural production. Nematode-trapping fungi (NTF) can produce traps to capture nematodes and are the main resource for controlling nematodes. The number of traps determines the capturing ability of NTF. Results Pseudomonas lurida is widely existed in different habitats, which produces active metabolites to induce trap formation of Arthrobotrys oligospora , a famous NTF. To further identify the active substances, metabolic regulation was carried out in the strain by molecular biological methods. A mutant strain P. lurida araC -PoprL with abundant secondary metabolites was constructed, and 19 metabolites ( 1 – 19 ) including a new compound, 1,1-dimethyl-1,3,4,9-tetrahydropyrano[3,4- b ]indole-3-carboxylic acid ( 1 ), were isolated and identified. The activity assay showed that 1-methylhydantoin ( 9 ) could effectively induce A. oligospora to produce traps. Conclusions P. lurida and the metabolite 1-methylhydantoin effectively induced trap formation in A. oligospora . Both provide sources for the screening of inducing active materials and show potential use in controlling plant parasitic nematodes. Graphical Abstract