Peptide-based quorum sensing systems inPaenibacillus polymyxa

Abstract

AbstractPaenibacillus polymyxais an agriculturally important plant growth-promoting rhizobacterium. ManyPaenibacillusspecies are known to be engaged in complex bacteria-bacteria and bacteria-host interactions, which in other species were shown to necessitate quorum sensing communication. However, to date no quorum sensing systems have been described inPaenibacillus. Here we show that the type strainP. polymyxaATCC 842 encodes at least 16 peptide-based communication systems. Each of these systems is comprised of a pro-peptide that is secreted to the growth medium and processed to generate a mature short peptide. Each peptide has a cognate intracellular receptor of the RRNPP family, and we show that external addition ofP. polymyxacommunication peptides leads to reprogramming of the transcriptional response. We found that these quorum sensing systems are conserved across hundreds of species belonging to thePaenibacillaceaefamily, with some species encoding more than 25 different peptide-receptor pairs, representing a record number of quorum sensing systems encoded in a single genome.