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Mathieu Picardeau - One of the best experts on this subject based on the ideXlab platform.
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Characterization of LE3 and LE4, the only lytic phages known to infect the spirochete Leptospira
Scientific Reports, 2018Co-Authors: Olivier Schiettekatte, Mathieu Picardeau, Antony Vincent, Christian Malosse, Pierre Lechat, Julia Chamot-rooke, Frédéric Veyrier, Pascale BourhyAbstract:Leptospira is a phylogenetically unique group of bacteria, and includes the causative agents of leptospirosis, the most globally prevalent zoonosis. Bacteriophages in Leptospira are largely unexplored. To date, a genomic sequence is available for only one temperate leptophage called LE1. Here, we sequenced and analysed the first genomes of the lytic phages LE3 and LE4 that can infect the Saprophyte Leptospira biflexa using the lipopolysaccharide O-antigen as receptor. Bioinformatics analysis showed that the 48-kb LE3 and LE4 genomes are similar and contain 62% genes whose function cannot be predicted. Mass spectrometry led to the identification of 21 and 23 phage proteins in LE3 and LE4, respectively. However we did not identify significant similarities with other phage genomes. A search for prophages close to LE4 in the Leptospira genomes allowed for the identification of a related plasmid in L. interrogans and a prophage-like region in the draft genome of a clinical isolate of L. mayottensis. Long-read whole genome sequencing of the L. mayottensis revealed that the genome contained a LE4 phage-like circular plasmid. Further isolation and genomic comparison of leptophages should reveal their role in the genetic evolution of Leptospira. Recently, there has been a renewed interest in bacteriophages for their potential use as alternatives to conventional antibiotics 1 , and also in understanding their contribution in evolution of bacteria 2,3. In addition, phages could be used to develop new genetic tools such as replicative vectors from different compatibility groups and phage-delivery systems. Unfortunately, little is known about the diversity of phages among the genus Leptospira. Leptospira are ubiquitous organisms that are found as free-living Saprophytes in environmental water and soil, or as pathogens that can cause acute or chronic infections in animals. A third group that is composed of intermediate species (in regards to their pathogenesis) of Leptospira, is phylogenetically closely related to the pathogenic species and can cause mild infections 4. Leptospirosis is an emerging waterborne zoonosis which results in more than one million human cases a year with a fatality rate frequently exceeding 10% 5. To the best of our knowledge, the only phages that have been isolated, purified, and phenotypically characterized in the genus Leptospira are: vB_LbiM_LE1 (renamed 6 , and abbreviated LE1), vB_LbiM_LE3 (LE3), and vB_LbiM_LE4 (LE4) 7. These tailed phages have been isolated from urban sewage and infect the Saprophyte L. biflexa. The LE1 temperate phage genome was previously sequenced 8 and an Escherichia coli-L. biflexa shuttle vector was generated by cloning the replication origin of LE1 9. Until now, the virulent phages LE3 and LE4 have not been further characterized at the genomic and proteomic levels. In addition to these three phages, phage-like particles were also observed following mitomycin C induction of a pathogenic strain carrying a circular plasmid with phage-related genes, but these phage-like particles were not purified 10. Recently, comparative analyses of genome sequences have suggested the existence of prophages and genomic islands within the genus Leptospira 11,12. Putative prophages are found in infectious Leptospira species, including pathogenic and intermediate species, and absent in saprophytic Leptospira species, suggesting that phages may have had a major role in the emergence of the pathogens and/or in the acquisition of virulence factors. Analysis of the complete genomes of 20 Leptospira species led to the description of several predicted prophage regions 11 , including LE1-like and Mu-like prophages. In addition, the existence of two other groups of prophages have been proposed: a 22-kb region which was initially described in L. interrogans serovar Lai but that is present in most
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acquisition of negative complement regulators by the Saprophyte leptospira biflexa expressing liga or ligb confers enhanced survival in human serum
Immunology Letters, 2016Co-Authors: Monica Marcela Castiblancovalencia, Mathieu Picardeau, Cláudio Pereira Figueira, Silvio Arruda Vasconcellos, Tatiana R Fraga, Leandro Carvalho Dantas Breda, Elsio A Wunder, Angela S Barbosa, Lourdes IsaacAbstract:Leptospiral immunoglobulin-like (Lig) proteins are surface exposed molecules present in pathogenic but not in saprophytic Leptospira species. We have previously shown that Lig proteins interact with the soluble complement regulators Factor H (FH), FH like-1 (FHL-1), FH related-1 (FHR-1) and C4b Binding Protein (C4BP). In this study, we used the Saprophyte L. biflexa serovar Patoc as a surrogate host to address the specific role of LigA and LigB proteins in leptospiral complement evasion. L. biflexa expressing LigA or LigB was able to acquire FH and C4BP. Bound complement regulators retained their cofactor activities of FI in the proteolytic cleavage of C3b and C4b. Moreover, heterologous expression of ligA and ligB genes in the Saprophyte L. biflexa enhanced bacterial survival in human serum. Complement deposition on lig-transformed L. biflexa was assessed by flow cytometry analysis. With regard to MAC deposition, L. biflexa expressing LigA or LigB presented an intermediate profile: MAC deposition levels were greater than those found in the pathogenic L. interrogans, but lower than those observed for L. biflexa wildtype. In conclusion, Lig proteins contribute to in vitro control of complement activation on the leptospiral surface, promoting an increased bacterial survival in human serum.
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Pathogenic but not Saprophyte Leptospira spp. degrade DNA.
2015Co-Authors: Emilia Scharrig, Mathieu Picardeau, Agostina Carestia, María F. Ferrer, Maia Cédola, Gabriela Pretre, Ricardo Drut, Mirta Schattner, Ricardo M. GómezAbstract:Representative analysis of DNA digestion by gel electrophoresis. From left to right: plasmid DNA (100 ng/μL) after incubation with PBS (negative control), DNase I (positive control), and live Leptospira interrogans serovar Copenhageni (LIC) or Leptospira biflexa serovar Patoc (Patoc) (1x108/mL) after 60 minutes of incubation at 37°C.
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Heterologous expression of pathogen-specific genes ligA and ligB in the Saprophyte Leptospira biflexa confers enhanced adhesion to cultured cells and fibronectin
BMC microbiology, 2011Co-Authors: Cláudio Pereira Figueira, Julio Croda, Henry A. Choy, David A. Haake, Mitermayer G. Reis, Mathieu PicardeauAbstract:In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira, but not in Saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the Saprophyte Leptospira biflexa serovar Patoc. The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa. We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa. We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa, namely adhesion to eukaryotic cells and fibronectin in vitro. This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
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Heterologous expression of pathogen-specific genes ligA and ligB in the Saprophyte Leptospira biflexaconfers enhanced adhesion to cultured cells and fibronectin
BMC Microbiology, 2011Co-Authors: Cláudio Pereira Figueira, Julio Croda, Henry A. Choy, David A. Haake, Mitermayer G. Reis, Mathieu PicardeauAbstract:Background In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira , but not in Saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the Saprophyte Leptospira biflexa serovar Patoc. Results The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa . We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. Conclusions This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa . We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa , namely adhesion to eukaryotic cells and fibronectin in vitro . This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
Cláudio Pereira Figueira - One of the best experts on this subject based on the ideXlab platform.
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acquisition of negative complement regulators by the Saprophyte leptospira biflexa expressing liga or ligb confers enhanced survival in human serum
Immunology Letters, 2016Co-Authors: Monica Marcela Castiblancovalencia, Mathieu Picardeau, Cláudio Pereira Figueira, Silvio Arruda Vasconcellos, Tatiana R Fraga, Leandro Carvalho Dantas Breda, Elsio A Wunder, Angela S Barbosa, Lourdes IsaacAbstract:Leptospiral immunoglobulin-like (Lig) proteins are surface exposed molecules present in pathogenic but not in saprophytic Leptospira species. We have previously shown that Lig proteins interact with the soluble complement regulators Factor H (FH), FH like-1 (FHL-1), FH related-1 (FHR-1) and C4b Binding Protein (C4BP). In this study, we used the Saprophyte L. biflexa serovar Patoc as a surrogate host to address the specific role of LigA and LigB proteins in leptospiral complement evasion. L. biflexa expressing LigA or LigB was able to acquire FH and C4BP. Bound complement regulators retained their cofactor activities of FI in the proteolytic cleavage of C3b and C4b. Moreover, heterologous expression of ligA and ligB genes in the Saprophyte L. biflexa enhanced bacterial survival in human serum. Complement deposition on lig-transformed L. biflexa was assessed by flow cytometry analysis. With regard to MAC deposition, L. biflexa expressing LigA or LigB presented an intermediate profile: MAC deposition levels were greater than those found in the pathogenic L. interrogans, but lower than those observed for L. biflexa wildtype. In conclusion, Lig proteins contribute to in vitro control of complement activation on the leptospiral surface, promoting an increased bacterial survival in human serum.
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Heterologous expression of pathogen-specific genes ligA and ligB in the Saprophyte Leptospira biflexa confers enhanced adhesion to cultured cells and fibronectin
BMC microbiology, 2011Co-Authors: Cláudio Pereira Figueira, Julio Croda, Henry A. Choy, David A. Haake, Mitermayer G. Reis, Mathieu PicardeauAbstract:In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira, but not in Saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the Saprophyte Leptospira biflexa serovar Patoc. The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa. We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa. We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa, namely adhesion to eukaryotic cells and fibronectin in vitro. This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
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Heterologous expression of pathogen-specific genes ligA and ligB in the Saprophyte Leptospira biflexaconfers enhanced adhesion to cultured cells and fibronectin
BMC Microbiology, 2011Co-Authors: Cláudio Pereira Figueira, Julio Croda, Henry A. Choy, David A. Haake, Mitermayer G. Reis, Mathieu PicardeauAbstract:Background In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira , but not in Saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the Saprophyte Leptospira biflexa serovar Patoc. Results The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa . We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. Conclusions This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa . We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa , namely adhesion to eukaryotic cells and fibronectin in vitro . This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
Marcela Escobargomez - One of the best experts on this subject based on the ideXlab platform.
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scedosporium prolificans keratouveitis in association with a contact lens retained intraocularly over a long term
Journal of Clinical Microbiology, 2001Co-Authors: Stella N Arthur, Gene Howard, Qun Peng, Lisa L. Steed, David J Apple, Marcela EscobargomezAbstract:Scedosporium prolificans is a soil Saprophyte that is associated with a large variety of infectious processes and with respiratory colonization in immunocompetent and immunocompromised patients. We report the first described case of S. prolificans keratouveitis associated with the intraocular long-term retention of a contact lens in a 76-year-old female patient.
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case reports scedosporium prolificans keratouveitis in association with a contact lens retained intraocularly over a long term
2001Co-Authors: Stella N Arthur, Gene Howard, Qun Peng, Lisa L. Steed, David J Apple, Marcela EscobargomezAbstract:Scedosporium prolificans is a soil Saprophyte that is associated with a large variety of infectious processes and with respiratory colonization in immunocompetent and immunocompromised patients. We report the first described case of S. prolificans keratouveitis associated with the intraocular long-term retention of a contact lens in a 76-year-old female patient.
Julio Croda - One of the best experts on this subject based on the ideXlab platform.
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Heterologous expression of pathogen-specific genes ligA and ligB in the Saprophyte Leptospira biflexaconfers enhanced adhesion to cultured cells and fibronectin
BMC Microbiology, 2011Co-Authors: Cláudio Pereira Figueira, Julio Croda, Henry A. Choy, David A. Haake, Mitermayer G. Reis, Mathieu PicardeauAbstract:Background In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira , but not in Saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the Saprophyte Leptospira biflexa serovar Patoc. Results The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa . We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. Conclusions This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa . We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa , namely adhesion to eukaryotic cells and fibronectin in vitro . This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
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Heterologous expression of pathogen-specific genes ligA and ligB in the Saprophyte Leptospira biflexa confers enhanced adhesion to cultured cells and fibronectin
BMC microbiology, 2011Co-Authors: Cláudio Pereira Figueira, Julio Croda, Henry A. Choy, David A. Haake, Mitermayer G. Reis, Mathieu PicardeauAbstract:In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira, but not in Saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the Saprophyte Leptospira biflexa serovar Patoc. The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa. We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa. We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa, namely adhesion to eukaryotic cells and fibronectin in vitro. This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
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Heterologous expression of pathogen-specific genes ligA and ligB in the Saprophyte Leptospira biflexa confers enhanced adhesion to cultured cells and fibronectin
BMC Microbiology, 2011Co-Authors: Cláudio Figueira, Julio Croda, Henry Choy, David Haake, Mitermayer Reis, Mathieu PicardeauAbstract:Background In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira, but not in Saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the Saprophyte Leptospira biflexa serovar Patoc. Results The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa. We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. Conclusions This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa. We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa, namely adhesion to eukaryotic cells and fibronectin in vitro. This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
Jason Terpolilli - One of the best experts on this subject based on the ideXlab platform.
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Rhizobia: from Saprophytes to endosymbionts
Nature Reviews Microbiology, 2018Co-Authors: Philip Poole, Vinoy Ramachandran, Jason TerpolilliAbstract:Root secretion and plant immunity are key factors in controlling the assembly of root-associated microbiotas of which rhizobia are key members Rhizobia exist in soil and compete with the general microbiota before infecting legumes, typically through root hairs, and forming N_2-fixing bacteroids Rhizobia have complex pan-genomes. Some strains also have large plasmids or symbiosis islands, which are crucial for fitness, nodulation and N_2 fixation Rhizobia have specific host plants, which makes them excellent models for studying the mechanisms, timing and location of root colonization in host and non-host plants Some legumes, such as members of the invert repeat lacking clade, produce up to several hundred antimicrobial peptides to control bacteroid cell division and development Bacteroids receive carbon as dicarboxylates from legumes, and in exchange, they fix N_2 in a low O_2 environment and secrete ammonia to the plant. Bacteroids must balance electron flow to nitrogenase, lipids, polyhydroxybutyrate and O_2, and coordinate this process with reductant production by the tricarboxylic acid (TCA) cycle Rhizobia can exist as both free-living soil microbiota and plant-associated endosymbionts, which form N_2-fixing root nodules. In this Review, Poole, Ramachandran and Terpolilli explore the drastic lifestyle shift that underlies this transition and the associated plant–bacteria interactions. Rhizobia are some of the best-studied plant microbiota. These oligotrophic Alphaproteobacteria or Betaproteobacteria form symbioses with their legume hosts. Rhizobia must exist in soil and compete with other members of the microbiota before infecting legumes and forming N_2-fixing bacteroids. These dramatic lifestyle and developmental changes are underpinned by large genomes and even more complex pan-genomes, which encompass the whole population and are subject to rapid genetic exchange. The ability to respond to plant signals and chemoattractants and to colonize nutrient-rich roots are crucial for the competitive success of these bacteria. The availability of a large body of genomic, physiological, biochemical and ecological studies makes rhizobia unique models for investigating community interactions and plant colonization.
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Rhizobia: from Saprophytes to endosymbionts.
Nature reviews. Microbiology, 2018Co-Authors: Philip S. Poole, Vinoy K. Ramachandran, Jason TerpolilliAbstract:Rhizobia are some of the best-studied plant microbiota. These oligotrophic Alphaproteobacteria or Betaproteobacteria form symbioses with their legume hosts. Rhizobia must exist in soil and compete with other members of the microbiota before infecting legumes and forming N2-fixing bacteroids. These dramatic lifestyle and developmental changes are underpinned by large genomes and even more complex pan-genomes, which encompass the whole population and are subject to rapid genetic exchange. The ability to respond to plant signals and chemoattractants and to colonize nutrient-rich roots are crucial for the competitive success of these bacteria. The availability of a large body of genomic, physiological, biochemical and ecological studies makes rhizobia unique models for investigating community interactions and plant colonization.
