Bacterial Analogs of Plant Tetrahydropyridine Alkaloids Mediate Microbial Interactions in a Rhizosphere Model System.

摘要: Plants expend significant resources to select and maintain rhizosphere communities that benefit their growth protect them from pathogens. A better understanding of assembly function microbial will provide new avenues for improving crop production. Secretion antibiotics is one means by which bacteria interact with neighboring microbes sometimes change community composition. In our analysis a taxonomically diverse consortium the soybean rhizosphere, we found Pseudomonas koreensis selectively inhibits Flavobacterium johnsoniae other members Bacteroidetes grown in root exudate. genetic screen P. identified previously uncharacterized biosynthetic gene cluster responsible inhibitory activity. Metabolites were isolated based on biological activity characterized using tandem mass spectrometry, multidimensional nuclear magnetic resonance, Mosher ester analysis, leading discovery family bacterial tetrahydropyridine alkaloids, koreenceine D (metabolites 1 4). Three these metabolites are analogs plant alkaloid γ-coniceine. Comparative γ-coniceine pathway revealed distinct polyketide synthase routes defining scaffold, suggesting convergent evolution. Koreenceine-type pathways widely distributed among species, C was detected another species distantly related cluster. This work suggests plants convergently evolved ability produce similar can mediate interbacterial competition rhizosphere.IMPORTANCE The microbiomes critical host physiology development. Microbes attracted due massive secretion photosynthates roots. Microorganisms successfully join bulk soil have access more abundant molecules, producing highly competitive selective environment. as microbiomes, little known about basis individual species' behaviors within community. this study, between johnsoniae, two common inhabitants. We widespread several spp. necessary production novel alkaloids structural alkaloids. expand repertoire produced demonstrate role interactions bacteria.