P seudomonas corrugata crpCDE is part of the cyclic lipopeptide corpeptin biosynthetic gene cluster and is involved in bacterial virulence in tomato and in hypersensitive response in N icotiana benthamiana

P seudomonas corrugata CFBP 5454 produces two kinds of cyclic lipopeptides ( CLP s), cormycin A and corpeptins, both of which possess surfactant, antimicrobial and phytotoxic activities. In this study, we identified genes coding for a putative non‐ribosomal peptide synthetase and an ABC ‐type transport system involved in corpeptin production. These genes belong to the same transcriptional unit, designated crpCDE . The genetic organization of this locus is highly similar to other P seudomonas CLP biosynthetic clusters. Matrix‐assisted laser desorption ionization‐time of flight‐mass spectrometry ( MALDI‐TOF ‐ MS ) analysis revealed that transporter and synthetase genomic knock‐out mutants were unable to produce corpeptins, but continued to produce cormycin A . This suggests that CrpCDE is the only system involved in corpeptin production in P . corrugata CFBP 5454. In addition, phylogenetic analysis revealed that the CrpE ABC transporter clustered with the transporters of CLPs with a long peptide chain. Strains depleted in corpeptin production were significantly less virulent than the wild‐type strain when inoculated in tomato plants and induced only chlorosis when infiltrated into N icotiana benthamiana leaves. Thus, corpeptins are important effectors of P . corrugata interaction with plants. Expression analysis revealed that crpC transcription occurs at high cell density. Two LuxR transcriptional regulators, PcoR and RfiA , have a pivotal role in crpC expression and thus in corpeptin production.