The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata
Cyclic lipopeptides (CLPs) are considered as some of the most important secondary metabolites in different plant-associated bacteria, thanks to their antimicrobial, cytotoxic, and surfactant properties. In this study, our aim was to investigate the role of the Quorum Sensing (QS) system, PcoI/PcoR,...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-03-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/fmicb.2018.00521/full |
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| author | Grazia Licciardello Grazia Licciardello Andrea Caruso Patrizia Bella Rodolpho Gheleri Cinzia P. Strano Alice Anzalone Emmanouil A. Trantas Panagiotis F. Sarris Panagiotis F. Sarris Nalvo F. Almeida Vittoria Catara |
| author_facet | Grazia Licciardello Grazia Licciardello Andrea Caruso Patrizia Bella Rodolpho Gheleri Cinzia P. Strano Alice Anzalone Emmanouil A. Trantas Panagiotis F. Sarris Panagiotis F. Sarris Nalvo F. Almeida Vittoria Catara |
| author_sort | Grazia Licciardello |
| collection | DOAJ |
| description | Cyclic lipopeptides (CLPs) are considered as some of the most important secondary metabolites in different plant-associated bacteria, thanks to their antimicrobial, cytotoxic, and surfactant properties. In this study, our aim was to investigate the role of the Quorum Sensing (QS) system, PcoI/PcoR, and the LuxR-type transcriptional regulator RfiA in CLP production in the phytopatogenic bacterium, Pseudomonas corrugata based on our previous work where we reported that the pcoR and rfiA mutants were devoid of the CLPs cormycin and corpeptin production. Due to the close genetic link between the QS system and the RfiA (rfiA is co-transcribed with pcoI), it was difficult to ascertain the specific regulatory role in the expression of target genes. A transcriptional approach was undertaken to identify the specific role of the PcoR and RfiA transcriptional regulators for the expression of genes involved in CLP production. The RNA-seq-based transcriptional analysis of the wild-type (WT) strain CFBP 5454 in comparison with GL2 (pcoR mutant) and GLRFIA (rfiA mutant) was performed in cultural conditions favoring CLP production. Differential gene expression revealed that 152 and 130 genes have significantly different levels of expression in the pcoR and rfiA mutants, respectively. Of these, the genes linked to the biosynthesis of CLPs and alginate were positively controlled by both PcoR and RfiA. Blast homology analysis showed that 19 genes in a large CLP biosynthetic cluster involved in the production of three antimicrobial peptides, which span approximately 3.5% of the genome, are strongly over-expressed in the WT strain. Thus, PcoR and RfiA function mainly as activators in the production of bioactive CLPs, in agreement with phenotype analysis of mutants. RNA-seq also revealed that almost all the genes in the structural/biosynthetic cluster of alginate exopolysaccharide (EPS) are under the control of the PcoR–RfiA regulon, as supported by the 10-fold reduction in total EPS yield isolated in both mutants in comparison to the parent strain. A total of 68 and 38 gene expressions was independently regulated by PcoR or RfiA proteins, respectively, but at low level. qPCR experiments suggest that growth medium and plant environment influence the expression of CLP and alginate genes. |
| first_indexed | 2024-04-13T02:24:21Z |
| format | Article |
| id | doaj.art-f8b40dabf290498e8774fa8e3f56bc95 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-04-13T02:24:21Z |
| publishDate | 2018-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-f8b40dabf290498e8774fa8e3f56bc952022-12-22T03:06:50ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2018-03-01910.3389/fmicb.2018.00521319727The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugataGrazia Licciardello0Grazia Licciardello1Andrea Caruso2Patrizia Bella3Rodolpho Gheleri4Cinzia P. Strano5Alice Anzalone6Emmanouil A. Trantas7Panagiotis F. Sarris8Panagiotis F. Sarris9Nalvo F. Almeida10Vittoria Catara11Parco Scientifico e Tecnologico della Sicilia, Catania, ItalyDipartimento di Agricoltura, Alimentazione e Ambiente, Università degli Studi di Catania, Catania, ItalyDipartimento di Agricoltura, Alimentazione e Ambiente, Università degli Studi di Catania, Catania, ItalyDipartimento di Scienze Agrarie, Alimentari e Forestali, Università degli Studi di Palermo, Palermo, ItalySchool of Computing, Federal University of Mato Grosso do Sul, Campo Grande, BrazilDipartimento di Agraria, Università degli Studi “Mediterranea” di Reggio Calabria, Reggio Calabria, ItalyDipartimento di Agricoltura, Alimentazione e Ambiente, Università degli Studi di Catania, Catania, ItalyDepartment of Agriculture, School of Agriculture, Food and Nutrition, Technological Educational Institute of Crete, Heraklion, GreeceDepartment of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United KingdomInstitute of Molecular Biology and Biotechnology, Foundation for Research and Technology – Hellas, Heraklion, GreeceSchool of Computing, Federal University of Mato Grosso do Sul, Campo Grande, BrazilDipartimento di Agricoltura, Alimentazione e Ambiente, Università degli Studi di Catania, Catania, ItalyCyclic lipopeptides (CLPs) are considered as some of the most important secondary metabolites in different plant-associated bacteria, thanks to their antimicrobial, cytotoxic, and surfactant properties. In this study, our aim was to investigate the role of the Quorum Sensing (QS) system, PcoI/PcoR, and the LuxR-type transcriptional regulator RfiA in CLP production in the phytopatogenic bacterium, Pseudomonas corrugata based on our previous work where we reported that the pcoR and rfiA mutants were devoid of the CLPs cormycin and corpeptin production. Due to the close genetic link between the QS system and the RfiA (rfiA is co-transcribed with pcoI), it was difficult to ascertain the specific regulatory role in the expression of target genes. A transcriptional approach was undertaken to identify the specific role of the PcoR and RfiA transcriptional regulators for the expression of genes involved in CLP production. The RNA-seq-based transcriptional analysis of the wild-type (WT) strain CFBP 5454 in comparison with GL2 (pcoR mutant) and GLRFIA (rfiA mutant) was performed in cultural conditions favoring CLP production. Differential gene expression revealed that 152 and 130 genes have significantly different levels of expression in the pcoR and rfiA mutants, respectively. Of these, the genes linked to the biosynthesis of CLPs and alginate were positively controlled by both PcoR and RfiA. Blast homology analysis showed that 19 genes in a large CLP biosynthetic cluster involved in the production of three antimicrobial peptides, which span approximately 3.5% of the genome, are strongly over-expressed in the WT strain. Thus, PcoR and RfiA function mainly as activators in the production of bioactive CLPs, in agreement with phenotype analysis of mutants. RNA-seq also revealed that almost all the genes in the structural/biosynthetic cluster of alginate exopolysaccharide (EPS) are under the control of the PcoR–RfiA regulon, as supported by the 10-fold reduction in total EPS yield isolated in both mutants in comparison to the parent strain. A total of 68 and 38 gene expressions was independently regulated by PcoR or RfiA proteins, respectively, but at low level. qPCR experiments suggest that growth medium and plant environment influence the expression of CLP and alginate genes.http://journal.frontiersin.org/article/10.3389/fmicb.2018.00521/fullcyclic lipopeptidesRNA-seqnon-ribosomal peptidestranscriptional analysisexopolysaccarides |
| spellingShingle | Grazia Licciardello Grazia Licciardello Andrea Caruso Patrizia Bella Rodolpho Gheleri Cinzia P. Strano Alice Anzalone Emmanouil A. Trantas Panagiotis F. Sarris Panagiotis F. Sarris Nalvo F. Almeida Vittoria Catara The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata Frontiers in Microbiology cyclic lipopeptides RNA-seq non-ribosomal peptides transcriptional analysis exopolysaccarides |
| title | The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata |
| title_full | The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata |
| title_fullStr | The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata |
| title_full_unstemmed | The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata |
| title_short | The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in Pseudomonas corrugata |
| title_sort | luxr regulators pcor and rfia co regulate antimicrobial peptide and alginate production in pseudomonas corrugata |
| topic | cyclic lipopeptides RNA-seq non-ribosomal peptides transcriptional analysis exopolysaccarides |
| url | http://journal.frontiersin.org/article/10.3389/fmicb.2018.00521/full |
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