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Lv F, Zhan Y, Feng H, Sun W, Yin C, Han Y, Shao Y, Xue W, Jiang S, Ma Y, Hu H, Wei J, Yan Y, Lin M. Integrated Hfq-interacting RNAome and transcriptomic analysis reveals complex regulatory networks of nitrogen fixation in root-associated Pseudomonas stutzeri A1501. mSphere 2024; 9:e0076223. [PMID: 38747590 DOI: 10.1128/msphere.00762-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 04/10/2024] [Indexed: 06/26/2024] Open
Abstract
The RNA chaperone Hfq acts as a global regulator of numerous biological processes, such as carbon/nitrogen metabolism and environmental adaptation in plant-associated diazotrophs; however, its target RNAs and the mechanisms underlying nitrogen fixation remain largely unknown. Here, we used enhanced UV cross-linking immunoprecipitation coupled with high-throughput sequencing to identify hundreds of Hfq-binding RNAs probably involved in nitrogen fixation, carbon substrate utilization, biofilm formation, and other functions. Collectively, these processes endow strain A1501 with the requisite capabilities to thrive in the highly competitive rhizosphere. Our findings revealed a previously uncharted landscape of Hfq target genes. Notable among these is nifM, encoding an isomerase necessary for nitrogenase reductase solubility; amtB, encoding an ammonium transporter; oprB, encoding a carbohydrate porin; and cheZ, encoding a chemotaxis protein. Furthermore, we identified more than 100 genes of unknown function, which expands the potential direct regulatory targets of Hfq in diazotrophs. Our data showed that Hfq directly interacts with the mRNA of regulatory proteins (RsmA, AlgU, and NifA), regulatory ncRNA RsmY, and other potential targets, thus revealing the mechanistic links in nitrogen fixation and other metabolic pathways. IMPORTANCE Numerous experimental approaches often face challenges in distinguishing between direct and indirect effects of Hfq-mediated regulation. New technologies based on high-throughput sequencing are increasingly providing insight into the global regulation of Hfq in gene expression. Here, enhanced UV cross-linking immunoprecipitation coupled with high-throughput sequencing was employed to identify the Hfq-binding sites and potential targets in the root-associated Pseudomonas stutzeri A1501 and identify hundreds of novel Hfq-binding RNAs that are predicted to be involved in metabolism, environmental adaptation, and nitrogen fixation. In particular, we have shown Hfq interactions with various regulatory proteins' mRNA and their potential targets at the posttranscriptional level. This study not only enhances our understanding of Hfq regulation but, importantly, also provides a framework for addressing integrated regulatory network underlying root-associated nitrogen fixation.
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Affiliation(s)
- Fanyang Lv
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuhua Zhan
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haichao Feng
- College of Agriculture, Henan University, Kaifeng, Henan, China
| | - Wenyue Sun
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Changyan Yin
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yueyue Han
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yahui Shao
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wei Xue
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shanshan Jiang
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yiyuan Ma
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haonan Hu
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jinfeng Wei
- College of Agriculture, Henan University, Kaifeng, Henan, China
| | - Yongliang Yan
- Biotechnology Research Institute/National Key Laboratory of Agricultural Microbiology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Min Lin
- College of Agriculture, Henan University, Kaifeng, Henan, China
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Murkar R, von Heckel C, Walles H, Moch TB, Arens C, Davaris N, Weber A, Zuschratter W, Baumann S, Reinhardt J, Kopp S. Establishment of a Human Immunocompetent 3D Tissue Model to Enable the Long-Term Examination of Biofilm-Tissue Interactions. Bioengineering (Basel) 2024; 11:187. [PMID: 38391673 PMCID: PMC10885984 DOI: 10.3390/bioengineering11020187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/24/2024] Open
Abstract
Different studies suggest an impact of biofilms on carcinogenic lesion formation in varying human tissues. However, the mechanisms of cancer formation are difficult to examine in vivo as well as in vitro. Cell culture approaches, in most cases, are unable to keep a bacterial steady state without any overgrowth. In our approach, we aimed to develop an immunocompetent 3D tissue model which can mitigate bacterial outgrowth. We established a three-dimensional (3D) co-culture of human primary fibroblasts with pre-differentiated THP-1-derived macrophages on an SIS-muc scaffold which was derived by decellularisation of a porcine intestine. After establishment, we exposed the tissue models to define the biofilms of the Pseudomonas spec. and Staphylococcus spec. cultivated on implant mesh material. After 3 days of incubation, the cell culture medium in models with M0 and M2 pre-differentiated macrophages presented a noticeable turbidity, while models with M1 macrophages presented no noticeable bacterial growth. These results were validated by optical density measurements and a streak test. Immunohistology and immunofluorescent staining of the tissue presented a positive impact of the M1 macrophages on the structural integrity of the tissue model. Furthermore, multiplex ELISA highlighted the increased release of inflammatory cytokines for all the three model types, suggesting the immunocompetence of the developed model. Overall, in this proof-of-principle study, we were able to mitigate bacterial overgrowth and prepared a first step for the development of more complex 3D tissue models to understand the impact of biofilms on carcinogenic lesion formation.
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Affiliation(s)
- Rasika Murkar
- Core Facility Tissue Engineering, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Charlotte von Heckel
- Core Facility Tissue Engineering, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Heike Walles
- Core Facility Tissue Engineering, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Theresia Barbara Moch
- Core Facility Tissue Engineering, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Christoph Arens
- Department of Otorhinolaryngology, Head and Neck Surgery, University Clinic Giessen, 35392 Giessen, Germany
| | - Nikolaos Davaris
- Department of Otorhinolaryngology, Head and Neck Surgery, University Clinic Giessen, 35392 Giessen, Germany
| | - André Weber
- Photonscore GmbH, Brenneckestr. 20, 39118 Magdeburg, Germany
| | | | - Sönke Baumann
- Omicron-Laserage® Laserprodukte GmbH, Raiffeisenstr. 5e, 63110 Rodgau, Germany
| | - Jörg Reinhardt
- MedFact Engineering GmbH, Hammerstrasse 3, 79540 Lörrach, Germany
| | - Sascha Kopp
- Core Facility Tissue Engineering, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
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Li Y, Narayanan M, Shi X, Chen X, Li Z, Ma Y. Biofilms formation in plant growth-promoting bacteria for alleviating agro-environmental stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167774. [PMID: 37848152 DOI: 10.1016/j.scitotenv.2023.167774] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/02/2023] [Accepted: 10/10/2023] [Indexed: 10/19/2023]
Abstract
Biofilm formation represents a pivotal and adaptable trait among microorganisms within natural environments. This attribute plays a multifaceted role across diverse contexts, including environmental, aquatic, industrial, and medical systems. While previous research has primarily focused on the adverse impacts of biofilms, harnessing their potential effectively could confer substantial advantages to humanity. In the face of escalating environmental pressures (e.g., drought, salinity, extreme temperatures, and heavy metal pollution), which jeopardize global crop yields, enhancing crop stress tolerance becomes a paramount endeavor for restoring sufficient food production. Recently, biofilm-forming plant growth-promoting bacteria (PGPB) have emerged as promising candidates for agricultural application. These biofilms are evidence of microorganism colonization on plant roots. Their remarkable stress resilience empowers crops to thrive and yield even in harsh conditions. This is accomplished through increased root colonization, improved soil properties, and the synthesis of valuable secondary metabolites (e.g., ACC deaminase, acetin, 2,3-butanediol, proline, etc.). This article elucidates the mechanisms underpinning the role of biofilm-forming PGPB in bolstering plant growth amidst environmental challenges. Furthermore, it explores the tangible applications of these biofilms in agriculture and delves into strategies for manipulating biofilm formation to extract maximal benefits in practical crop production scenarios.
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Affiliation(s)
- Yujia Li
- College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Mathiyazhagan Narayanan
- Division of Research and Innovation, Department of Biotechnology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Science, Chennai 602105, Tamil Nadu, India
| | - Xiaojun Shi
- College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Xinping Chen
- College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Zhenlun Li
- College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Ying Ma
- College of Resources and Environment, Southwest University, Chongqing 400716, China.
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Venkataraman M, Yñigez-Gutierrez A, Infante V, MacIntyre A, Fernandes-Júnior PI, Ané JM, Pfleger B. Synthetic Biology Toolbox for Nitrogen-Fixing Soil Microbes. ACS Synth Biol 2023; 12:3623-3634. [PMID: 37988619 PMCID: PMC10754042 DOI: 10.1021/acssynbio.3c00414] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
The soil environment adjacent to plant roots, termed the rhizosphere, is home to a wide variety of microorganisms that can significantly affect the physiology of nearby plants. Microbes in the rhizosphere can provide nutrients, secrete signaling compounds, and inhibit pathogens. These processes could be manipulated with synthetic biology to enhance the agricultural performance of crops grown for food, energy, or environmental remediation, if methods can be implemented in these nonmodel microbes. A common first step for domesticating nonmodel organisms is the development of a set of genetic engineering tools, termed a synthetic biology toolbox. A toolbox comprises transformation protocols, replicating vectors, genome engineering (e.g., CRISPR/Cas9), constitutive and inducible promoter systems, and other gene expression control elements. This work validated synthetic biology toolboxes in three nitrogen-fixing soil bacteria: Azotobacter vinelandii, Stutzerimonas stutzeri (Pseudomonas stutzeri), and a new isolate of Klebsiella variicola. All three organisms were amenable to transformation and reporter protein expression, with several functional inducible systems available for each organism. S. stutzeri and K. variicola showed more reliable plasmid-based expression, resulting in successful Cas9 recombineering to create scarless deletions and insertions. Using these tools, we generated mutants with inducible nitrogenase activity and introduced heterologous genes to produce resorcinol products with relevant biological activity in the rhizosphere.
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Affiliation(s)
- Maya Venkataraman
- Department of Chemical and Biological Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Audrey Yñigez-Gutierrez
- Department of Chemical and Biological Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Valentina Infante
- Department of Bacteriology, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - April MacIntyre
- Department of Bacteriology, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Valent BioSciences, Libertyville, Illinois 60048, United States
| | - Paulo Ivan Fernandes-Júnior
- Department of Bacteriology, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Brazilian Agricultural Research Corporation (Embrapa), Tropical Semi-Arid Research Center (Embrapa Semiárido), Petrolina, Pernambuco 56302-970, Brazil
| | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Microbiology Doctoral Training Program, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Brian Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Microbiology Doctoral Training Program, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
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Genomic Insights and Functional Analysis Reveal Plant Growth Promotion Traits of Paenibacillus mucilaginosus G78. Genes (Basel) 2023; 14:genes14020392. [PMID: 36833318 PMCID: PMC9956331 DOI: 10.3390/genes14020392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/21/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023] Open
Abstract
Paenibacillus mucilaginosus has widely been reported as a plant growth-promoting rhizobacteria (PGPR). However, the important genomic insights into plant growth promotion in this species remain undescribed. In this study, the genome of P. mucilaginosus G78 was sequenced using Illumina NovaSeq PE150. It contains 8,576,872 bp with a GC content of 58.5%, and was taxonomically characterized. Additionally, a total of 7337 genes with 143 tRNAs, 41 rRNAs, and 5 ncRNAs were identified. This strain can prohibit the growth of the plant pathogen, but also has the capability to form biofilm, solubilize phosphate, and produce IAA. Twenty-six gene clusters encoding secondary metabolites were identified, and the genotypic characterization indirectly proved its resistant ability to ampicillin, bacitracin, polymyxin and chloramphenicol. The putative exopolysaccharide biosynthesis and biofilm formation gene clusters were explored. According to the genetic features, the potential monosaccharides of its exopolysaccharides for P. mucilaginosus G78 may include glucose, mannose, galactose, fucose, that can probably be acetylated and pyruvated. Conservation of the pelADEFG compared with other 40 Paenibacillus species suggests that Pel may be specific biofilm matrix component in P. mucilaginosus. Several genes relevant to plant growth-promoting traits, i.e., IAA production and phosphate solubilization are well conserved compared with other 40 other Paenibacillus strains. The current study can benefit for understanding the plant growth-promoting traits of P. mucilaginosus as well as its potential application in agriculture as PGPR.
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Terrettaz C, Cabete B, Geiser J, Valentini M, Gonzalez D. KaiC-like proteins contribute to stress resistance and biofilm formation in environmental Pseudomonas species. Environ Microbiol 2022; 25:894-913. [PMID: 36579711 DOI: 10.1111/1462-2920.16330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/26/2022] [Indexed: 12/30/2022]
Abstract
KaiC is the central cog of the circadian clock in Cyanobacteria. Close homologues of this protein are widespread among nonphotosynthetic bacteria, but the function, interaction network, and mechanism of action of these proteins are still largely unknown. Here, we focus on KaiC homologues found in environmental Pseudomonas species. Using bioinformatics, we describe the distribution of this protein family in the genus and reveal a conserved interaction network comprising a histidine kinase and response regulator. We characterize experimentally the only KaiC homologue present in Pseudomonas putida KT2440 and Pseudomonas protegens CHA0. Through phenotypic assays and transcriptomics, we show that KaiC is involved in osmotic and oxidative stress resistance in P. putida and in biofilm production in both species. KaiC homologues are found in different phosphorylation states and physically interact with a cognate histidine kinase and response regulator. In contrast with cyanobacterial counterparts, the expression and phosphorylation of KaiC homologues do not correlate with light variations under 12:12 light: dark cycles in either Pseudomonas species, and KaiC itself is not required to support a light-driven behaviour in P. putida. Overall, this suggests that KaiC homologues in Pseudomonas species are involved in environmental stress resistance but not in responses to diurnal rhythms.
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Affiliation(s)
- Céline Terrettaz
- Laboratoire de Microbiologie, Institut de Biologie, Université de Neuchâtel, Neuchâtel, Switzerland
| | - Bruno Cabete
- Laboratoire de Microbiologie, Institut de Biologie, Université de Neuchâtel, Neuchâtel, Switzerland
| | - Johan Geiser
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Martina Valentini
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Diego Gonzalez
- Laboratoire de Microbiologie, Institut de Biologie, Université de Neuchâtel, Neuchâtel, Switzerland
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Studying Plant-Insect Interactions through the Analyses of the Diversity, Composition, and Functional Inference of Their Bacteriomes. Microorganisms 2022; 11:microorganisms11010040. [PMID: 36677331 PMCID: PMC9863603 DOI: 10.3390/microorganisms11010040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
As with many other trophic interactions, the interchange of microorganisms between plants and their herbivorous insects is unavoidable. To test the hypothesis that the composition and diversity of the insect bacteriome are driven by the bacteriome of the plant, the bacteriomes of both the plant Datura inoxia and its specialist insect Lema daturaphila were characterised using 16S sRNA gene amplicon sequencing. Specifically, the bacteriomes associated with seeds, leaves, eggs, guts, and frass were described and compared. Then, the functions of the most abundant bacterial lineages found in the samples were inferred. Finally, the patterns of co-abundance among both bacteriomes were determined following a multilayer network approach. In accordance with our hypothesis, most genera were shared between plants and insects, but their abundances differed significantly within the samples collected. In the insect tissues, the most abundant genera were Pseudomonas (24.64%) in the eggs, Serratia (88.46%) in the gut, and Pseudomonas (36.27%) in the frass. In contrast, the most abundant ones in the plant were Serratia (40%) in seeds, Serratia (67%) in foliar endophytes, and Hymenobacter (12.85%) in foliar epiphytes. Indeed, PERMANOVA analysis showed that the composition of the bacteriomes was clustered by sample type (F = 9.36, p < 0.001). Functional inferences relevant to the interaction showed that in the plant samples, the category of Biosynthesis of secondary metabolites was significantly abundant (1.4%). In turn, the category of Xenobiotics degradation and metabolism was significantly present (2.5%) in the insect samples. Finally, the phyla Proteobacteria and Actinobacteriota showed a pattern of co-abundance in the insect but not in the plant, suggesting that the co-abundance and not the presence−absence patterns might be more important when studying ecological interactions.
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Yan J, Guo X, Li J, Li Y, Sun H, Li A, Cao B. RpoN is required for the motility and contributes to the killing ability of Plesiomonas shigelloides. BMC Microbiol 2022; 22:299. [PMID: 36510135 PMCID: PMC9743648 DOI: 10.1186/s12866-022-02722-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND RpoN, also known as σ54, first reported in Escherichia coli, is a subunit of RNA polymerase that strictly controls the expression of different genes by identifying specific promoter elements. RpoN has an important regulatory function in carbon and nitrogen metabolism and participates in the regulation of flagellar synthesis, bacterial motility and virulence. However, little is known about the effect of RpoN in Plesiomonas shigelloides. RESULTS To identify pathways controlled by RpoN, RNA sequencing (RNA-Seq) of the WT and the rpoN deletion strain was carried out for comparison. The RNA-seq results showed that RpoN regulates ~ 13.2% of the P. shigelloides transcriptome, involves amino acid transport and metabolism, glycerophospholipid metabolism, pantothenate and CoA biosynthesis, ribosome biosynthesis, flagellar assembly and bacterial secretion system. Furthermore, we verified the results of RNA-seq using quantitative real-time reverse transcription PCR, which indicated that the absence of rpoN caused downregulation of more than half of the polar and lateral flagella genes in P. shigelloides, and the ΔrpoN mutant was also non-motile and lacked flagella. In the present study, the ability of the ΔrpoN mutant to kill E. coli MG1655 was reduced by 54.6% compared with that of the WT, which was consistent with results in RNA-seq, which showed that the type II secretion system (T2SS-2) genes and the type VI secretion system (T6SS) genes were repressed. By contrast, the expression of type III secretion system genes was largely unchanged in the ΔrpoN mutant transcriptome and the ability of the ΔrpoN mutant to infect Caco-2 cells was also not significantly different compared with the WT. CONCLUSIONS We showed that RpoN is required for the motility and contributes to the killing ability of P. shigelloides and positively regulates the T6SS and T2SS-2 genes.
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Affiliation(s)
- Junxiang Yan
- grid.216938.70000 0000 9878 7032TEDA Institute of Biological Sciences and Biotechnology, Nankai University, No. 23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China
| | - Xueqian Guo
- grid.216938.70000 0000 9878 7032TEDA Institute of Biological Sciences and Biotechnology, Nankai University, No. 23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China
| | - Jinghao Li
- grid.216938.70000 0000 9878 7032TEDA Institute of Biological Sciences and Biotechnology, Nankai University, No. 23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China
| | - Yuehua Li
- grid.216938.70000 0000 9878 7032TEDA Institute of Biological Sciences and Biotechnology, Nankai University, No. 23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China
| | - Hongmin Sun
- grid.216938.70000 0000 9878 7032TEDA Institute of Biological Sciences and Biotechnology, Nankai University, No. 23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China
| | - Ang Li
- grid.216938.70000 0000 9878 7032State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin, 300353 China
| | - Boyang Cao
- grid.216938.70000 0000 9878 7032TEDA Institute of Biological Sciences and Biotechnology, Nankai University, No.23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, No. 23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China ,grid.216938.70000 0000 9878 7032Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, No. 23, Hongda StreetTianjin Economic and Technological Development Area, Tianjin, 300457 China
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Lv F, Zhan Y, Lu W, Ke X, Shao Y, Ma Y, Zheng J, Yang Z, Jiang S, Shang L, Ma Y, Cheng L, Elmerich C, Yan Y, Lin M. Regulation of hierarchical carbon substrate utilization, nitrogen fixation, and root colonization by the Hfq/Crc/CrcZY genes in Pseudomonas stutzeri. iScience 2022; 25:105663. [PMID: 36505936 PMCID: PMC9730152 DOI: 10.1016/j.isci.2022.105663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 09/08/2022] [Accepted: 11/18/2022] [Indexed: 11/24/2022] Open
Abstract
Bacteria of the genus Pseudomonas consume preferred carbon substrates in nearly reverse order to that of enterobacteria, and this process is controlled by RNA-binding translational repressors and regulatory ncRNA antagonists. However, their roles in microbe-plant interactions and the underlying mechanisms remain uncertain. Here we show that root-associated diazotrophic Pseudomonas stutzeri A1501 preferentially catabolizes succinate, followed by the less favorable substrate citrate, and ultimately glucose. Furthermore, the Hfq/Crc/CrcZY regulatory system orchestrates this preference and contributes to optimal nitrogenase activity and efficient root colonization. Hfq has a central role in this regulatory network through different mechanisms of action, including repressing the translation of substrate-specific catabolic genes, activating the nitrogenase gene nifH posttranscriptionally, and exerting a positive effect on the transcription of an exopolysaccharide gene cluster. Our results illustrate an Hfq-mediated mechanism linking carbon metabolism to nitrogen fixation and root colonization, which may confer rhizobacteria competitive advantages in rhizosphere environments.
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Affiliation(s)
- Fanyang Lv
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuhua Zhan
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wei Lu
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiubin Ke
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yahui Shao
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yiyuan Ma
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Juan Zheng
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhimin Yang
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shanshan Jiang
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Liguo Shang
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yao Ma
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lei Cheng
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, China
| | | | - Yongliang Yan
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China,Corresponding author
| | - Min Lin
- Biotechnology Research Institute/Key Laboratory of Agricultural Microbiome (MARA), Chinese Academy of Agricultural Sciences, Beijing, China,Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, China,Corresponding author
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Han Y, Li C, Yan Y, Lin M, Ke X, Zhang Y, Zhan Y. Post-transcriptional control of bacterial nitrogen metabolism by regulatory noncoding RNAs. World J Microbiol Biotechnol 2022; 38:126. [PMID: 35666348 PMCID: PMC9170634 DOI: 10.1007/s11274-022-03287-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/12/2022] [Indexed: 12/04/2022]
Abstract
Nitrogen metabolism is the most basic process of material and energy metabolism in living organisms, and processes involving the uptake and use of different nitrogen sources are usually tightly regulated at the transcriptional and post-transcriptional levels. Bacterial regulatory noncoding RNAs are novel post-transcriptional regulators that repress or activate the expression of target genes through complementarily pairing with target mRNAs; therefore, these noncoding RNAs play an important regulatory role in many physiological processes, such as bacterial substance metabolism and stress response. In recent years, a study found that noncoding RNAs play a vital role in the post-transcriptional regulation of nitrogen metabolism, which is currently a hot topic in the study of bacterial nitrogen metabolism regulation. In this review, we present an overview of recent advances that increase our understanding on the regulatory roles of bacterial noncoding RNAs and describe in detail how noncoding RNAs regulate biological nitrogen fixation and nitrogen metabolic engineering. Furthermore, our goal is to lay a theoretical foundation for better understanding the molecular mechanisms in bacteria that are involved in environmental adaptations and metabolically-engineered genetic modifications.
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Affiliation(s)
- Yueyue Han
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chao Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yongliang Yan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Min Lin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiubin Ke
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yunhua Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China. .,School of Resources and Environment, Anhui Agricultural University, Hefei, China.
| | - Yuhua Zhan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
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11
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Shao Y, Yin C, Lv F, Jiang S, Wu S, Han Y, Xue W, Ma Y, Zheng J, Zhan Y, Ke X, Lu W, Lin M, Shang L, Yan Y. The Sigma Factor AlgU Regulates Exopolysaccharide Production and Nitrogen-Fixing Biofilm Formation by Directly Activating the Transcription of pslA in Pseudomonas stutzeri A1501. Genes (Basel) 2022; 13:genes13050867. [PMID: 35627252 PMCID: PMC9141998 DOI: 10.3390/genes13050867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas stutzeri A1501, a plant-associated diazotrophic bacterium, prefers to conform to a nitrogen-fixing biofilm state under nitrogen-deficient conditions. The extracytoplasmic function (ECF) sigma factor AlgU is reported to play key roles in exopolysaccharide (EPS) production and biofilm formation in the Pseudomonas genus; however, the function of AlgU in P. stutzeri A1501 is still unclear. In this work, we mainly investigated the role of algU in EPS production, biofilm formation and nitrogenase activity in A1501. The algU mutant ΔalgU showed a dramatic decrease both in the EPS production and the biofilm formation capabilities. In addition, the biofilm-based nitrogenase activity was reduced by 81.4% in the ΔalgU mutant. The transcriptional level of pslA, a key Psl-like (a major EPS in A1501) synthesis-related gene, was almost completely inhibited in the algU mutant and was upregulated by 2.8-fold in the algU-overexpressing strain. A predicted AlgU-binding site was identified in the promoter region of pslA. The DNase I footprinting assays indicated that AlgU could directly bind to the pslA promoter, and β-galactosidase activity analysis further revealed mutations of the AlgU-binding boxes drastically reduced the transcriptional activity of the pslA promoter; moreover, we also demonstrated that AlgU was positively regulated by RpoN at the transcriptional level and negatively regulated by the RNA-binding protein RsmA at the posttranscriptional level. Taken together, these data suggest that AlgU promotes EPS production and nitrogen-fixing biofilm formation by directly activating the transcription of pslA, and the expression of AlgU is controlled by RpoN and RsmA at different regulatory levels.
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Affiliation(s)
- Yahui Shao
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Changyan Yin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Fanyang Lv
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Shanshan Jiang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Shaoyu Wu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Yueyue Han
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Wei Xue
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Yiyuan Ma
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Juan Zheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Yuhua Zhan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Xiubin Ke
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Wei Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Min Lin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Liguo Shang
- School of Basic Medicine, GuangXi University of Chinese Medicine, Nanning 530200, China
- Correspondence: (L.S.); (Y.Y.)
| | - Yongliang Yan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
- Correspondence: (L.S.); (Y.Y.)
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12
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Yu C, Yang F, Xue D, Wang X, Chen H. The Regulatory Functions of σ 54 Factor in Phytopathogenic Bacteria. Int J Mol Sci 2021; 22:ijms222312692. [PMID: 34884502 PMCID: PMC8657755 DOI: 10.3390/ijms222312692] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/16/2021] [Accepted: 11/22/2021] [Indexed: 12/24/2022] Open
Abstract
σ54 factor (RpoN), a type of transcriptional regulatory factor, is widely found in pathogenic bacteria. It binds to core RNA polymerase (RNAP) and regulates the transcription of many functional genes in an enhancer-binding protein (EBP)-dependent manner. σ54 has two conserved functional domains: the activator-interacting domain located at the N-terminal and the DNA-binding domain located at the C-terminal. RpoN directly binds to the highly conserved sequence, GGN10GC, at the −24/−12 position relative to the transcription start site of target genes. In general, bacteria contain one or two RpoNs but multiple EBPs. A single RpoN can bind to different EBPs in order to regulate various biological functions. Thus, the overlapping and unique regulatory pathways of two RpoNs and multiple EBP-dependent regulatory pathways form a complex regulatory network in bacteria. However, the regulatory role of RpoN and EBPs is still poorly understood in phytopathogenic bacteria, which cause economically important crop diseases and pose a serious threat to world food security. In this review, we summarize the current knowledge on the regulatory function of RpoN, including swimming motility, flagella synthesis, bacterial growth, type IV pilus (T4Ps), twitching motility, type III secretion system (T3SS), and virulence-associated phenotypes in phytopathogenic bacteria. These findings and knowledge prove the key regulatory role of RpoN in bacterial growth and pathogenesis, as well as lay the groundwork for further elucidation of the complex regulatory network of RpoN in bacteria.
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Affiliation(s)
- Chao Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (F.Y.)
| | - Fenghuan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (F.Y.)
| | - Dingrong Xue
- National Engineering Laboratory of Grain Storage and Logistics, Academy of National Food and Strategic Reserves Administration, No. 11 Baiwanzhuang Street, Xicheng District, Beijing 100037, China;
| | - Xiuna Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (F.Y.)
- Correspondence:
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Das J, Kumar R, Yadav SK, Jha G. The alternative sigma factors, rpoN1 and rpoN2 are required for mycophagous activity of Burkholderia gladioli strain NGJ1. Environ Microbiol 2021; 24:2781-2796. [PMID: 34766435 DOI: 10.1111/1462-2920.15836] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 11/26/2022]
Abstract
Bacteria utilize RpoN, an alternative sigma factor (σ54) to grow in diverse habitats, including nitrogen-limiting conditions. Here, we report that a rice-associated mycophagous bacterium Burkholderia gladioli strain NGJ1 encodes two paralogues of rpoN viz. rpoN1 and rpoN2. Both of them are upregulated during 24 h of mycophagous interaction with Rhizoctonia solani, a polyphagous fungal pathogen. Disruption of either one of rpoNs renders the mutant NGJ1 bacterium defective in mycophagy, whereas ectopic expression of respective rpoN genes restores mycophagy in the complementing strains. NGJ1 requires rpoN1 and rpoN2 for efficient biocontrol to prevent R. solani to establish disease in rice and tomato. Further, we have identified 17 genes having RpoN regulatory motif in NGJ1, majority of them encode potential type III secretion system (T3SS) effectors, nitrogen assimilation, and cellular transport-related functions. Several of these RpoN regulated genes as well as certain previously reported T3SS apparatus (hrcC and hrcN) and effector (Bg_9562 and endo-β-1,3-glucanase) encoding genes are upregulated in NGJ1 but not in ΔrpoN1 or ΔrpoN2 mutant bacterium, during mycophagous interaction with R. solani. This highlights that RpoN1 and RpoN2 modulate T3SS, nitrogen assimilation as well as cellular transport systems in NGJ1 and thereby promote bacterial mycophagy.
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Affiliation(s)
- Joyati Das
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
| | - Rahul Kumar
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
| | - Sunil Kumar Yadav
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
| | - Gopaljee Jha
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
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Sierra Cacho D, Zamorano Sánchez DS, Xiqui-Vázquez ML, Viruega Góngora VI, Ramírez-Mata A, Baca BE. CdgC, a Cyclic-di-GMP Diguanylate Cyclase of Azospirillum baldaniorum Is Involved in Internalization to Wheat Roots. FRONTIERS IN PLANT SCIENCE 2021; 12:748393. [PMID: 34745182 PMCID: PMC8564387 DOI: 10.3389/fpls.2021.748393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Azospirillum baldaniorum is a plant growth-promoting rhizobacterium (PGPR) capable of fixing nitrogen, the synthesis of several phytohormones including indole-acetic acid, and induction of plant defenses against phytopathogens. To establish a successful and prolonged bacteria-plant interaction, A. baldaniorum can form biofilms, bacterial communities embedded in a self-made matrix formed by extracellular polymeric substances which provide favorable conditions for survival. A key modulator of biofilm formation is the second messenger bis-(3'-5')-cyclic-dimeric-GMP (c-di-GMP), which is synthesized by diguanylate cyclases (DGC) and degraded by specific phosphodiesterases. In this study, we analyzed the contribution of a previously uncharacterized diguanylate cyclase designated CdgC, to biofilm formation and bacterial-plant interaction dynamics. We showed that CdgC is capable of altering c-di-GMP levels in a heterologous host, strongly supporting its function as a DGC. The deletion of cdgC resulted in alterations in the three-dimensional structure of biofilms in a nitrogen-source dependent manner. CdgC was required for optimal colonization of wheat roots. Since we also observed that CdgC played an important role in exopolysaccharide production, we propose that this signaling protein activates a physiological response that results in the strong attachment of bacteria to the roots, ultimately contributing to an optimal bacterium-plant interaction. Our results demonstrate that the ubiquitous second messenger c-di-GMP is a key factor in promoting plant colonization by the PGPR A. baldaniorum by allowing proficient internalization in wheat roots. Understanding the molecular basis of PGPR-plant interactions will enable the design of better biotechnological strategies of agro-industrial interest.
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Affiliation(s)
- Daniel Sierra Cacho
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
| | - David S. Zamorano Sánchez
- Programa de Biología de Sistemas y Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Maria Luisa Xiqui-Vázquez
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
| | - Víctor Iván Viruega Góngora
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
| | - Alberto Ramírez-Mata
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
| | - Beatriz E. Baca
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Mexico
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