ABSTRACT
Studies of the EtOAc extract of the culture broth and methanol extract of the mycelium of Stereum insigne CGMCC5.57 led to the isolation of one new dihydrobenzofuran (1) and six known compounds (2-7). The structures of compounds were elucidated mainly by HRESIMS experiments, and 1D, 2D NMR spectroscopy analysis. This is the first report about the chemical constitutes of the fungus S. insigne.
Subject(s)
Basidiomycota/chemistry , Benzofurans/isolation & purification , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antinematodal Agents/chemistry , Antinematodal Agents/pharmacology , Bacillus subtilis/drug effects , Benzaldehydes/chemistry , Benzaldehydes/isolation & purification , Benzaldehydes/pharmacology , Benzofurans/chemistry , Drug Evaluation, Preclinical/methods , Ergosterol/analogs & derivatives , Ergosterol/chemistry , Ergosterol/isolation & purification , Ergosterol/pharmacology , Escherichia coli/drug effects , Magnetic Resonance Spectroscopy , Molecular Structure , Mycelium/chemistry , Spectrometry, Mass, Electrospray IonizationABSTRACT
In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode-predatory form; this predacious form is characterized by formation of specialized cellular structures or 'traps'. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator-prey interactions in prey defense mechanisms.