1
|
Goo E, Hwang I. Control of bacterial quorum threshold for metabolic homeostasis and cooperativity. Microbiol Spectr 2024; 12:e0335323. [PMID: 38084969 PMCID: PMC10783058 DOI: 10.1128/spectrum.03353-23] [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: 09/13/2023] [Accepted: 11/02/2023] [Indexed: 01/13/2024] Open
Abstract
IMPORTANCE The mechanisms used by various bacteria to determine whether their density is sufficient to meet the QS threshold, how stringently bacterial cells block QS initiation until the QS threshold is reached, and the impacts of low-density bacterial cells encountering conditions that exceed the QS threshold are longstanding gaps in QS research. We demonstrated that translational control of the QS signaling biosynthetic gene creates a stringent QS threshold to maintain metabolic balance at low cell densities. The emergence of non-cooperative cells underlines the critical role of stringent QS modulation in maintaining the integrity of the bacterial QS system, demonstrating that a lack of such control can serve as a selection pressure. The fate of quorum-calling cells exposed to exceeding the QS threshold clarifies QS bacteria evolution in complex ecosystems.
Collapse
Affiliation(s)
- Eunhye Goo
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| |
Collapse
|
2
|
Iqbal A, Nwokocha G, Tiwari V, Barphagha IK, Grove A, Ham JH, Doerrler WT. A membrane protein of the rice pathogen Burkholderia glumae required for oxalic acid secretion and quorum sensing. MOLECULAR PLANT PATHOLOGY 2023; 24:1400-1413. [PMID: 37428013 PMCID: PMC10576180 DOI: 10.1111/mpp.13376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/26/2023] [Accepted: 06/26/2023] [Indexed: 07/11/2023]
Abstract
Bacterial panicle blight is caused by Burkholderia glumae and results in damage to rice crops worldwide. Virulence of B. glumae requires quorum sensing (QS)-dependent synthesis and export of toxoflavin, responsible for much of the damage to rice. The DedA family is a conserved membrane protein family found in all bacterial species. B. glumae possesses a member of the DedA family, named DbcA, which we previously showed is required for toxoflavin secretion and virulence in a rice model of infection. B. glumae secretes oxalic acid as a "common good" in a QS-dependent manner to combat toxic alkalinization of the growth medium during the stationary phase. Here, we show that B. glumae ΔdbcA fails to secrete oxalic acid, leading to alkaline toxicity and sensitivity to divalent cations, suggesting a role for DbcA in oxalic acid secretion. B. glumae ΔdbcA accumulated less acyl-homoserine lactone (AHL) QS signalling molecules as the bacteria entered the stationary phase, probably due to nonenzymatic inactivation of AHL at alkaline pH. Transcription of toxoflavin and oxalic acid operons was down-regulated in ΔdbcA. Alteration of the proton motive force with sodium bicarbonate also reduced oxalic acid secretion and expression of QS-dependent genes. Overall, the data show that DbcA is required for oxalic acid secretion in a proton motive force-dependent manner, which is critical for QS of B. glumae. Moreover, this study supports the idea that sodium bicarbonate may serve as a chemical for treatment of bacterial panicle blight.
Collapse
Affiliation(s)
- Asif Iqbal
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - George Nwokocha
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Vijay Tiwari
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Inderjit K. Barphagha
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLouisianaUSA
| | - Anne Grove
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Jong Hyun Ham
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLouisianaUSA
| | - William T. Doerrler
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| |
Collapse
|
3
|
Qi Z, Sun N, Liu C. Glyoxylate cycle maintains the metabolic homeostasis of Pseudomonas aeruginosa in viable but nonculturable state induced by chlorine stress. Microbiol Res 2023; 270:127341. [PMID: 36870195 DOI: 10.1016/j.micres.2023.127341] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/18/2023] [Accepted: 02/18/2023] [Indexed: 02/23/2023]
Abstract
Bacteria enter a viable but non-culturable (VBNC) state with low metabolic activity to cope with environmental stress (e.g., chlorine disinfection). Elucidating the mechanism and key pathway of VBNC bacteria maintaining low metabolic competence is of great significance to realize their effective control and reduce their environmental and health risks. This study discovered that the glyoxylate cycle is a key metabolic pathway for VBNC bacteria, but not for culturable bacteria. And blocking the glyoxylate cycle pathway inhibited the reactivation and led to the death of VBNC bacteria. The main mechanisms involved the breakdown of material and energy metabolism and the antioxidant system. Gas chromatography-tandem mass spectrometry analysis showed that blocking the glyoxylate cycle led to a disruption of carbohydrate metabolism and fatty acid catabolism in VBNC bacteria. As a result, the energy metabolism system of VBNC bacteria collapsed and the abundance of energy metabolites (ATP, NAD+ and NADP+) decreased significantly. Moreover, the decrease in the level of quorum sensing signaling molecules (quinolinone and N-Butanoyl-D-homoserine lactone) inhibited the synthesis of extracellular polymeric substances (EPSs) and biofilm formation. And the downregulation of glycerophospholipid metabolic competence increased the permeability of cell membranes, leading to the entry of large amounts of hypochlorous acid (HClO) into the bacteria. In addition, the down-regulation of nucleotide metabolism, glutathione metabolism, and the reduction of antioxidant enzyme content resulted in the inability to scavenge reactive oxygen species (ROS) generated by chlorine stress. The large production of ROS and the reduction of antioxidants together led to the breakdown of the antioxidant system of VBNC bacteria. In short, the glyoxylate cycle is the key metabolism pathway of VBNC bacteria for stress resistance and maintaining cellular metabolic balance, and targeting the glyoxylate cycle represents an attractive strategy for developing new and efficient disinfection methods for the control of VBNC bacteria.
Collapse
Affiliation(s)
- Zheng Qi
- School of Environmental Science and Engineering, Shandong Key Laboratory of Environmental Processes and Health, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72 Jimo Binhai Road, Qingdao, Shandong 266237, PR China
| | - Na Sun
- Jining Ecology and Environment Bureau, 30 Pipashan Street, Rencheng, Jining, Shandong, PR China
| | - Chunguang Liu
- School of Environmental Science and Engineering, Shandong Key Laboratory of Environmental Processes and Health, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72 Jimo Binhai Road, Qingdao, Shandong 266237, PR China; Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong, PR China.
| |
Collapse
|
4
|
Park J, Jung H, Mannaa M, Lee SY, Lee HH, Kim N, Han G, Park DS, Lee SW, Lee SW, Seo YS. Genome-guided comparative in planta transcriptome analyses for identifying cross-species common virulence factors in bacterial phytopathogens. FRONTIERS IN PLANT SCIENCE 2022; 13:1030720. [PMID: 36466249 PMCID: PMC9709210 DOI: 10.3389/fpls.2022.1030720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/31/2022] [Indexed: 06/17/2023]
Abstract
Plant bacterial disease is a complex outcome achieved through a combination of virulence factors that are activated during infection. However, the common virulence factors across diverse plant pathogens are largely uncharacterized. Here, we established a pan-genome shared across the following plant pathogens: Burkholderia glumae, Ralstonia solanacearum, and Xanthomonas oryzae pv. oryzae. By overlaying in planta transcriptomes onto the pan-genome, we investigated the expression profiles of common genes during infection. We found over 70% of identical patterns for genes commonly expressed by the pathogens in different plant hosts or infection sites. Co-expression patterns revealed the activation of a signal transduction cascade to recognize and respond to external changes within hosts. Using mutagenesis, we uncovered a relationship between bacterial virulence and functions highly conserved and shared in the studied genomes of the bacterial phytopathogens, including flagellar biosynthesis protein, C4-dicarboxylate ABC transporter, 2-methylisocitrate lyase, and protocatechuate 3,4-dioxygenase (PCD). In particular, the disruption of PCD gene led to attenuated virulence in all pathogens and significantly affected phytotoxin production in B. glumae. This PCD gene was ubiquitously distributed in most plant pathogens with high homology. In conclusion, our results provide cross-species in planta models for identifying common virulence factors, which can be useful for the protection of crops against diverse pathogens.
Collapse
Affiliation(s)
- Jungwook Park
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
- Biotechnology Research Division, National Institute of Fisheries Science, Busan, South Korea
| | - Hyejung Jung
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Mohamed Mannaa
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Seung Yeup Lee
- Department of Applied Bioscience, Dong-A University, Busan, South Korea
| | - Hyun-Hee Lee
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Namgyu Kim
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Gil Han
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Dong-Soo Park
- Paddy Crop Division, National Institute of Crop Science, Rural Development Administration, Miryang, South Korea
| | - Sang-Won Lee
- Department of Plant Molecular Systems Biotech & Crop Biotech Institute, KyungHee University, Yongin, South Korea
| | - Seon-Woo Lee
- Department of Applied Bioscience, Dong-A University, Busan, South Korea
| | - Young-Su Seo
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| |
Collapse
|
5
|
Marunga J, Kang Y, Goo E, Hwang I. Hierarchical regulation of Burkholderia glumae type III secretion system by GluR response regulator and Lon protease. MOLECULAR PLANT PATHOLOGY 2022; 23:1461-1471. [PMID: 35717678 PMCID: PMC9452761 DOI: 10.1111/mpp.13241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 05/25/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Expression of type III secretion system (T3SS) genes, which are important for the virulence of phytopathogenic bacteria, is induced in the plant apoplastic environment or artificially amended growth conditions. Wild-type Burkholderia glumae BGR1, which causes rice panicle blight, induced a hypersensitive response (HR) in tobacco plants, whereas the T3SS genes were not significantly expressed in the commonly used hrp induction medium. T3SS gene expression in B. glumae was dependent on HrpB, a well known T3SS gene transcriptional regulator. Here, we report a stepwise mechanism of T3SS gene regulation by the GluR response regulator and Lon protease in addition to HrpB-mediated control of T3SS genes in B. glumae. The gluR mutant showed no HR in tobacco plants and exhibited attenuated virulence in rice plants. GluR directly activated hrpB expression, indicating that hrpB belongs to the GluR regulon. The lon mutation allowed high expression of the T3SS genes in nutrient-rich media. Lon directly activated gluR expression but repressed hrpB expression, indicating that Lon acts as a regulator rather than a protease. However, the lon mutant failed to induce an HR and virulence, suggesting that Lon not only acts as a negative regulator, but also has an essential, yet to be determined role for T3SS. Our results demonstrate the involvement of the two-component system response regulator GluR and Lon in T3SS gene regulation, providing new insight into the complex interplay mechanisms of regulators involved in T3SS gene expression in bacteria-plant interactions.
Collapse
Affiliation(s)
- Joan Marunga
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
| | - Yongsung Kang
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Eunhye Goo
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Ingyu Hwang
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
| |
Collapse
|
6
|
Kang M, Lim JY, Kim J, Hwang I, Goo E. Influence of genomic structural variations and nutritional conditions on the emergence of quorum sensing-dependent gene regulation defects in Burkholderia glumae. Front Microbiol 2022; 13:950600. [PMID: 35910611 PMCID: PMC9335073 DOI: 10.3389/fmicb.2022.950600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/29/2022] [Indexed: 11/30/2022] Open
Abstract
Bacteria often change their genetic and physiological traits to survive in harsh environments. To determine whether, in various strains of Burkholderia glumae, genomic diversity is associated with the ability to adapt to ever-changing environments, whole genomes of 44 isolates from different hosts and regions were analyzed. Whole-genome phylogenetic analysis of the 44 isolates revealed six clusters and two divisions. While all isolates possessed chromosomes 1 and 2, strains BGR80S and BGR81S had one chromosome resulting from the merging of the two chromosomes. Upon comparison of genomic structures to the prototype BGR1, inversions, deletions, and rearrangements were found within or between chromosomes 1 and/or 2 in the other isolates. When three isolates—BGR80S, BGR15S, and BGR21S, representing clusters III, IV, and VI, respectively—were grown in Luria-Bertani medium, spontaneous null mutations were identified in qsmR encoding a quorum-sensing master regulator. Six days after subculture, qsmR mutants were found at detectable frequencies in BGR15S and BGR21S, and reached approximately 40% at 8 days after subculture. However, the qsmR mutants appeared 2 days after subculture in BGR80S and dominated the population, reaching almost 80%. No qsmR mutant was detected at detectable frequency in BGR1 or BGR13S. The spontaneous qsmR mutants outcompeted their parental strains in the co-culture. Daily addition of glucose or casamino acids to the batch cultures of BGR80S delayed emergence of qsmR mutants and significantly reduced their incidence. These results indicate that spontaneous qsmR mutations are correlated with genomic structures and nutritional conditions.
Collapse
Affiliation(s)
- Minhee Kang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Jae Yun Lim
- School of Systems Biomedical Science, Soongsil University, Seoul, South Korea
| | - Jinwoo Kim
- Department of Plant Medicine and Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju, South Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Eunhye Goo
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
- *Correspondence: Eunhye Goo,
| |
Collapse
|
7
|
Genome Sequence and Adaptation Analysis of the Human and Rice Pathogenic Strain Burkholderia glumae AU6208. Pathogens 2021; 10:pathogens10020087. [PMID: 33498266 PMCID: PMC7909282 DOI: 10.3390/pathogens10020087] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/01/2022] Open
Abstract
Burkholderia glumae causes rice (Oryza sativa) bacterial panicle blight, which is an increasingly economically important disease worldwide. As the first B. glumae strain isolated from patients with chronic infections, AU6208 has been reported as an opportunistic clinic pathogen. However, our understanding of the molecular mechanism underlying human pathogenesis by B. glumae remains rudimentary. In this study, we report the complete genome sequence of the human-isolated B. glumae strain AU6208 and compare this to the genome of the rice-pathogenic B. glumae type strain LMG 2196T. Analysis of the average nucleotide identity demonstrated 99.4% similarity between the human- and plant-pathogenic strains. However, the phenotypic results from this study suggest a history of niche adaptation and divergence. In particular, we found 44 genes were predicted to be horizontally transferred into AU6208, and most of these genes were upregulated in conditions that mimic clinical conditions. In these, the gene pair sbnAB encodes key enzymes in antibiotic biosynthesis. These results suggest that horizontal gene transfer in AU6208 may be responsible for selective advantages in its pathogenicity in humans. Our analysis of the AU6208 genome and comparison with that of LMG 2196T reveal the evolutionary signatures of B. glumae in the process of switching niches from plants to humans.
Collapse
|
8
|
Chodkowski JL, Shade A. Exometabolite Dynamics over Stationary Phase Reveal Strain-Specific Responses. mSystems 2020; 5:e00493-20. [PMID: 33361318 PMCID: PMC7762789 DOI: 10.1128/msystems.00493-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/25/2020] [Indexed: 11/20/2022] Open
Abstract
Microbial exponential growth is expected to occur infrequently in environments that have long periods of nutrient starvation punctuated by short periods of high nutrient flux. These conditions likely impose nongrowth states for microbes. However, nongrowth states are uncharacterized for the majority of environmental bacteria, especially in regard to exometabolite production. We compared exometabolites produced over stationary phase across three environmental bacteria: Burkholderia thailandensis E264 (ATCC 700388), Chromobacterium violaceum ATCC 31532, and Pseudomonas syringae pv. tomato DC3000 (ATCC BAA-871). We grew each strain in monoculture and investigated exometabolite dynamics from mid-exponential to stationary phases. We focused on exometabolites that were released into the medium and accumulated over 45 h, including approximately 20 h of stationary phase. We also analyzed transcripts (transcriptome sequencing [RNA-seq]) to interpret exometabolite output. We found that the majority of exometabolites released were strain specific, with a subset of identified exometabolites involved in both central and secondary metabolism. Transcript analysis supported that exometabolites were released from intact cells, as various transporters had either increased or consistent transcripts through time. Interestingly, we found that succinate was one of the most abundant identifiable exometabolites for all strains and that each strain rerouted their metabolic pathways involved in succinate production during stationary phase. These results show that nongrowth states can be metabolically dynamic and that environmental bacteria can enrich a minimal environment with diverse chemical compounds as a consequence of growth and postgrowth maintenance in stationary phase. This work provides insights into microbial community interactions via exometabolites under conditions of growth cessation or limitation.IMPORTANCE Nongrowth states are common for bacteria that live in environments that are densely populated and predominantly nutrient exhausted, and yet these states remain largely uncharacterized in cellular metabolism and metabolite output. Here, we investigated and compared stationary-phase exometabolites and RNA transcripts for each of three environmental bacterial strains. We observed that diverse exometabolites were produced and provide evidence that these exometabolites accumulate over time through release by intact cells. Additionally, each bacterial strain had a characteristic exometabolite profile and exhibited dynamics in exometabolite composition. This work affirms that stationary phase is metabolically dynamic, with each strain tested creating a unique chemical signature in the extracellular space and altering metabolism in stationary phase. These findings set the stage for understanding how bacterial populations can support surrounding neighbors in environments with prolonged nutrient exhaustion through exometabolite-mediated interspecies interactions.
Collapse
Affiliation(s)
- John L Chodkowski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Ashley Shade
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan, USA
- Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
9
|
Kwak GY, Goo E, Jeong H, Hwang I. Adverse effects of adaptive mutation to survive static culture conditions on successful fitness of the rice pathogen Burkholderia glumae in a host. PLoS One 2020; 15:e0238151. [PMID: 32833990 PMCID: PMC7444824 DOI: 10.1371/journal.pone.0238151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/10/2020] [Indexed: 11/18/2022] Open
Abstract
Bacteria often possess relatively flexible genome structures and adaptive genetic variants that allow survival in unfavorable growth conditions. Bacterial survival tactics in disadvantageous microenvironments include mutations that are beneficial against threats in their niche. Here, we report that the aerobic rice bacterial pathogen Burkholderia glumae BGR1 changes a specific gene for improved survival in static culture conditions. Static culture triggered formation of colony variants with deletions or point mutations in the gene bspP (BGLU_RS28885), which putatively encodes a protein that contains PDC2, PAS-9, SpoIIE, and HATPase domains. The null mutant of bspP survived longer in static culture conditions and produced a higher level of bis-(3'-5')-cyclic dimeric guanosine monophosphate than the wild type. Expression of the bacterial cellulose synthase regulator (bcsB) gene was upregulated in the mutant, consistent with the observation that the mutant formed pellicles faster than the wild type. Mature pellicle formation was observed in the bspP mutant before pellicle formation in wild-type BGR1. However, the population density of the bspP null mutant decreased substantially when grown in Luria-Bertani medium with vigorous agitation due to failure of oxalate-mediated detoxification of the alkaline environment. The bspP null mutant was less virulent and exhibited less effective colonization of rice plants than the wild type. All phenotypes caused by mutations in bspP were recovered to those of the wild type by genetic complementation. Thus, although wild-type B. glumae BGR1 prolonged viability by spontaneous mutation under static culture conditions, such genetic changes negatively affected colonization in rice plants. These results suggest that adaptive gene sacrifice of B. glumae to survive unfavorable growth conditions is not always desirable as it can adversely affect adaptability in the host.
Collapse
Affiliation(s)
- Gi-Young Kwak
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Eunhye Goo
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Haeyoon Jeong
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| |
Collapse
|
10
|
Botero D, Monk J, Rodríguez Cubillos MJ, Rodríguez Cubillos A, Restrepo M, Bernal-Galeano V, Reyes A, González Barrios A, Palsson BØ, Restrepo S, Bernal A. Genome-Scale Metabolic Model of Xanthomonas phaseoli pv. manihotis: An Approach to Elucidate Pathogenicity at the Metabolic Level. Front Genet 2020; 11:837. [PMID: 32849823 PMCID: PMC7432306 DOI: 10.3389/fgene.2020.00837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 07/10/2020] [Indexed: 01/05/2023] Open
Abstract
Xanthomonas phaseoli pv. manihotis (Xpm) is the causal agent of cassava bacterial blight, the most important bacterial disease in this crop. There is a paucity of knowledge about the metabolism of Xanthomonas and its relevance in the pathogenic process, with the exception of the elucidation of the xanthan biosynthesis route. Here we report the reconstruction of the genome-scale model of Xpm metabolism and the insights it provides into plant-pathogen interactions. The model, iXpm1556, displayed 1,556 reactions, 1,527 compounds, and 890 genes. Metabolic maps of central amino acid and carbohydrate metabolism, as well as xanthan biosynthesis of Xpm, were reconstructed using Escher (https://escher.github.io/) to guide the curation process and for further analyses. The model was constrained using the RNA-seq data of a mutant of Xpm for quorum sensing (QS), and these data were used to construct context-specific models (CSMs) of the metabolism of the two strains (wild type and QS mutant). The CSMs and flux balance analysis were used to get insights into pathogenicity, xanthan biosynthesis, and QS mechanisms. Between the CSMs, 653 reactions were shared; unique reactions belong to purine, pyrimidine, and amino acid metabolism. Alternative objective functions were used to demonstrate a trade-off between xanthan biosynthesis and growth and the re-allocation of resources in the process of biosynthesis. Important features altered by QS included carbohydrate metabolism, NAD(P)+ balance, and fatty acid elongation. In this work, we modeled the xanthan biosynthesis and the QS process and their impact on the metabolism of the bacterium. This model will be useful for researchers studying host-pathogen interactions and will provide insights into the mechanisms of infection used by this and other Xanthomonas species.
Collapse
Affiliation(s)
- David Botero
- Laboratory of Mycology and Plant Pathology (LAMFU), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
- Grupo de Diseño de Productos y Procesos (GDPP), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
- Max Planck Tandem Group in Computational Biology, Universidad de Los Andes, Bogotá, Colombia
- Grupo de Biología Computacional y Ecología Microbiana, Department of Biological Sciences, Universidad de Los Andes, Bogotá, Colombia
| | - Jonathan Monk
- Systems Biology Research Group, Department of Bioengineering, University of California, San Diego, San Diego, CA, United States
| | - María Juliana Rodríguez Cubillos
- Laboratory of Mycology and Plant Pathology (LAMFU), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
- Grupo de Diseño de Productos y Procesos (GDPP), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
| | | | - Mariana Restrepo
- Laboratory of Mycology and Plant Pathology (LAMFU), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
| | - Vivian Bernal-Galeano
- Laboratory of Mycology and Plant Pathology (LAMFU), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
| | - Alejandro Reyes
- Max Planck Tandem Group in Computational Biology, Universidad de Los Andes, Bogotá, Colombia
- Grupo de Biología Computacional y Ecología Microbiana, Department of Biological Sciences, Universidad de Los Andes, Bogotá, Colombia
| | - Andrés González Barrios
- Grupo de Diseño de Productos y Procesos (GDPP), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
| | - Bernhard Ø. Palsson
- Systems Biology Research Group, Department of Bioengineering, University of California, San Diego, San Diego, CA, United States
| | - Silvia Restrepo
- Laboratory of Mycology and Plant Pathology (LAMFU), Department of Chemical and Food Engineering, Universidad de Los Andes, Bogotá, Colombia
| | - Adriana Bernal
- Laboratory of Molecular Interactions of Agricultural Microbes, LIMMA, Department of Biological Sciences, Universidad de Los Andes, Bogotá, Colombia
| |
Collapse
|
11
|
Lelis T, Peng J, Barphagha I, Chen R, Ham JH. The Virulence Function and Regulation of the Metalloprotease Gene prtA in the Plant-Pathogenic Bacterium Burkholderia glumae. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:841-852. [PMID: 30694091 DOI: 10.1094/mpmi-11-18-0312-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Bacterial panicle blight caused by Burkholderia glumae is a major bacterial disease of rice. Our preliminary RNA-seq study showed that a serine metalloprotease gene, prtA, is regulated in a similar manner to the genes for the biosynthesis and transport of toxoflavin, which is a known major virulence factor of B. glumae. prtA null mutants of the virulent strain B. glumae 336gr-1 did not show a detectable extracellular protease activity, indicating that prtA is the solely responsible gene for the extracellular protease activity detected from this bacterium. In addition, inoculation of rice panicles with the prtA mutants resulted in a significant reduction of disease severity compared with the wild-type parent strain, suggesting the requirement of prtA for the full virulence of B. glumae. A double mutant deficient in both serine metalloprotease and toxoflavin (ΔtoxA/prtA-) exhibited a further numeric but not statistically significant decrease of disease development compared with the ΔtoxA strain. Both the prtA-driven extracellular protease activity and the toxoflavin production were dependent on both the tofI/tofR quorum-sensing and the global regulatory gene qsmR, indicating the important roles of the two global regulatory factors for the bacterial pathogenesis by this pathogen.
Collapse
Affiliation(s)
- Tiago Lelis
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Jingyu Peng
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Inderjit Barphagha
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Ruoxi Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Jong Hyun Ham
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| |
Collapse
|
12
|
A single mutation in rapP induces cheating to prevent cheating in Bacillus subtilis by minimizing public good production. Commun Biol 2018; 1:133. [PMID: 30272012 PMCID: PMC6123732 DOI: 10.1038/s42003-018-0136-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/10/2018] [Indexed: 12/30/2022] Open
Abstract
Cooperation is beneficial to group behaviors like multicellularity, but is vulnerable to exploitation by cheaters. Here we analyze mechanisms that protect against exploitation of extracellular surfactin in swarms of Bacillus subtilis. Unexpectedly, the reference strain NCIB 3610 displays inherent resistance to surfactin-non-producing cheaters, while a different wild isolate is susceptible. We trace this interstrain difference down to a single amino acid change in the plasmid-borne regulator RapP, which is necessary and sufficient for cheater mitigation. This allele, prevalent in many Bacillus species, optimizes transcription of the surfactin operon to the minimum needed for full cooperation. When combined with a strain lacking rapP, NCIB 3610 acts as a cheater itself—except it does not harm the population at high proportions since it still produces enough surfactin. This strategy of minimal production is thus a doubly advantageous mechanism to limit exploitation of public goods, and is readily evolved from existing regulatory networks. Lyons and Kolter describe a single-point mutation in the plasmid-borne gene rapP of Bacillus subtilis that optimizes surfactin transcription to express the minimum required for cooperation. The decrease in the production of this public good significantly prevented the exploitation of cooperative traits by cheaters.
Collapse
|