Abstract
Erwinia amylovora is the causal agent of fire blight, an economically-important disease affecting apple and pear production worldwide. Initial contact and infection of the host by E. amylovora mainly occurs in flowers, or in young leaves at actively-growing shoot tips. Infection via shoot tips encompasses several distinct steps which include the utilization of a Type III secretion system (T3SS) to establish bacterial populations within the apoplast, infection of the parenchyma, invasion of the xylem, attachment to xylem vessels, biofilm formation, and the eventual colonization of the xylem which manifests outwardly as wilting symptoms in the plant. After E. amylovora gains entry into the xylem, initial attachment to the xylem vessels is mediated by type I fimbriae. Conversely, the small RNA (sRNA) chaperone Hfq and associated sRNA ArcZ negatively regulate attachment and promote biofilm maturation. Attachment and biofilm formation within the xylem are enhanced by the mechanical force emerging from the flow of xylem sap. The second messenger molecule cyclic-di-GMP (c-di-GMP) regulates the transition into the biofilm phase of the infection process of E. amylovora. C-di-GMP also regulates the production of critical exopolysaccharides amylovoran and cellulose, that lend to the structural stability and growth of biofilms within the xylem vessels. In this review, we provide an in-depth evaluation of the process of biofilm formation occurring within the host, as a result of E. amylovora infection. We also provide a model encompassing the different physical and signaling factors involved in biofilm initiation and maturation in E. amylovora, and highlight what needs to be done in the future.
Similar content being viewed by others
References
Allison DG, Ruiz B, SanJose C, Jaspe A, Gilbert P (1998) Extracellular products as mediators of the formation and detachment of Pseudomonas fluorescens biofilms. FEMS Microbiol Lett 167:179–184
Andersson RA, Eriksson AR, Heikinheimo R, Mäe A, Pirhonen M, Kõiv V, Hyytiäinen H, Tuikkala A, Palva ET (2000) Quorum sensing in the plant pathogen Erwinia carotovora subsp. carotovora: the role of expREcc. Molecular Plant Microbe interactions 13:384–393
Aragón IM, Pérez-Mendoza D, Gallegos MT, Ramos C (2015) The c-di-GMP phosphodiesterase BifA is involved in the virulence of bacteria from the Pseudomonas syringae complex. Mol Plant Pathol 16:604–615
Barken KB, Pamp SJ, Yang L, Gjermansen M, Bertrand JJ, Klausen M, Givskov M, Whitchurch CB, Engel JN, Tolker-Nielsen T (2008) Roles of type IV pili, flagellum-mediated motility and extracellular DNA in the formation of mature multicellular structures in Pseudomonas aeruginosa biofilms. Environ Microbiol 10:2331–2343
Bernhard F, Coplin DL, Geider K (1993) A gene cluster for amylovoran synthesis in Erwinia amylovora: characterization and relationship to cps genes in Erwinia stewartii. Mol Gen Genet 239:158–168
Bogs J, Bruchmüller I, Erbar C, Geider K (1998) Colonization of host plants by the fire blight pathogen Erwinia amylovora marked with genes for bioluminescence and fluorescence. Phytopathology 88:416–421
Bubán T, Orosz-Kovács Z (2003) The nectary as the primary site of infection by Erwinia amylovora: a mini review. Plant Syst Evol 238:183–194
Buhtz A, Kolasa A, Arlt K, Walz C, Kehr J (2004) Xylem sap protein composition is conserved among different plant species. Planta 219:610–618
Burr T, Barnard AM, Corbett MJ, Pemberton CL, Simpson NJ, Salmond GP (2006) Identification of the central quorum sensing regulator of virulence in the enteric phytopathogen, Erwinia carotovora: the VirR repressor. Mol Microbiol 59:113–125
Caldwell D, Kim BS, Iyer-Pascuzzi AS (2017) Ralstonia solanacearum differentially colonizes roots of resistant and susceptible tomato plants. Phytopathology 107:528–536
Castiblanco LF, Sundin GW (2016) New insights on molecular regulation of biofilm formation in plant-associated bacteria. J Integr Plant Biol 58:362–372
Castiblanco LF, Sundin GW (2018) Cellulose production, activated by cyclic di-GMP through BcsA and BcsZ, is a virulence factor and an essential determinant of the three-dimensional architectures of biofilms formed by Erwinia amylovora Ea1189. Mol Plant Pathol 19:90–103
Chatterjee S, Killiny N, Almeida RP, Lindow SE (2010) Role of cyclic di-GMP in Xylella fastidiosa biofilm formation, plant virulence, and insect transmission. Molecular Plant Microbe Interactions 23:1356–1363
Cobine PA, Cruz LF, Navarrete F, Duncan D, Tygart M, De La Fuente L (2013) Xylella fastidiosa differentially accumulates mineral elements in biofilm and planktonic cells. PLoS One 8:e54936
Crosse JE, Goodman RN, Shaffer WH (1972) Leaf damage as a predisposing factor in the infection of apple shoots by Erwinia amylovora. Phytopathology 62:176–182
De La Fuente L, Parker JK, Oliver JE, Granger S, Brannen PM, van Santen E, Cobine PA (2013) The bacterial pathogen Xylella fastidiosa affects the leaf ionome of plant hosts during infection. PLoS One 8
De Souza AA, Ionescu M, Baccari C, da Silva AM, Lindow SE (2013) Phenotype overlap in Xylella fastidiosa is controlled by the cyclic di-GMP phosphodiesterase Eal in response to antibiotic exposure and diffusible signal factor-mediated cell-cell signaling. Appl Environ Microbiol 79:3444–3454
Dellagi A, Brisset MN, Paulin JP, Expert D (1998) Dual role of desferrioxamine in Erwinia amylovora pathogenicity. Molecular Plant Microbe Interactions 11:734–742
Dow JM, Crossman L, Findlay K, He YQ, Feng JX, Tang JL (2003) Biofilm dispersal in Xanthomonas campestris is controlled by cell–cell signaling and is required for full virulence to plants. Proceedings of the National Academy of Sciences USA 100:10995–11000
Edmunds AC, Castiblanco LF, Sundin GW, Waters CM (2013) Cyclic di-GMP modulates the disease progression of Erwinia amylovora. J Bacteriol 195:2155–2165
Flavier AB, Ganova-Raeva LM, Schell MA, Denny TP (1997) Hierarchical autoinduction in Ralstonia solanacearum: control of acyl-homoserine lactone production by a novel autoregulatory system responsive to 3-hydroxypalmitic acid methyl ester. J Bacteriol 179:7089–7097
Gao Y, Song J, Hu B, Zhang L, Liu Q, Liu F (2009) The luxS gene is involved in AI-2 production, pathogenicity, and some phenotypes in Erwinia amylovora. Curr Microbiol 58:1–10
Goodman RN, White JA (1981) Xylem parenchyma plasmolysis and vessel wall disorientation caused by Erwinia amylovora. Phytopathology 71:844–852
Gross M, Geier G, Rudolph K, Geider K (1992) Levan and levansucrase synthesized by the fire blight pathogen Erwinia amylovora. Physiol Mol Plant Pathol 40:371–381
Hall CW, Mah TF (2017) Molecular mechanisms of biofilm-based antibiotic resistance and tolerance in pathogenic bacteria. FEMS Microbiol Rev 41:276–301
Hossain MM, Tsuyumu S (2006) Flagella-mediated motility is required for biofilm formation by Erwinia carotovora subsp. carotovora. J Gen Plant Pathol 72:34–39
Ionescu M, Baccari C, Da Silva AM, Garcia A, Yokota K, Lindow SE (2013) Diffusible signal factor (DSF) synthase RpfF of Xylella fastidiosa is a multifunction protein also required for response to DSF. J Bacteriol 195:5273–5284
Jenal U, Reinders A, Lori C (2017) Cyclic di-GMP: second messenger extraordinaire. Nat Rev Microbiol 15:271
Johnson KB, Stockwell VO, Burgett DM, Sugar D, Loper JE (1993) Dispersal of Erwinia amylovora and Pseudomonas fluorescens by honey bees from hives to apple and pear blossoms. Phytopathology 83:478–484
Johnson KB, Sawyer TL, Temple TN (2006) Rates of epiphytic growth of Erwinia amylovora on flowers common in the landscape. Plant Dis 90:1331–1336
Kai K, Ohnishi H, Shimatani M, Ishikawa S, Mori Y, Kiba A, Ohnishi K, Tabuchi M, Hikichi Y (2015) Methyl 3-hydroxymyristate, a diffusible signal mediating phc quorum sensing in Ralstonia solanacearum. ChemBioChem 16:2309–2318
Kanchiswamy CN, Mohanta TK, Capuzzo A, Occhipinti A, Verrillo F, Maffei ME, Malnoy M (2013) Differential expression of CPKs and cytosolic Ca 2+ variation in resistant and susceptible apple cultivars (Malus x domestica) in response to the pathogen Erwinia amylovora and mechanical wounding. BMC Genomics 14:760
Karam GN (2005) Biomechanical model of the xylem vessels in vascular plants. Ann Bot 95:1179–1186
Kharadi RR, Sundin GW (2019) Physiological and microscopic characterization of cyclic-di-GMP-mediated autoaggregation in Erwinia amylovora. Front Microbiol 10:468
Kharadi RR, Castiblanco LF, Waters CM, Sundin GW (2019) Phosphodiesterase genes regulate amylovoran production, biofilm formation, and virulence in Erwinia amylovora. Appl Environ Microbiol 85:e02233–e02218
Khokhani, D., Lowe-Power, T.M., Tran, T.M. and Allen, C., 2017. A single regulator mediates strategic switching between attachment/spread and growth/virulence in the plant pathogen Ralstonia solanacearum. mBio 8: 00895-17
Klee SM, Sinn JP, Finley M, Allman EL, Smith PB, Aimufua O, Sitther V, Lehman BL, Krawczyk T, Peter KA, McNellis TW (2019) Erwinia amylovora auxotrophic mutant exometabolomics and virulence on apples. Appl Environ Microbiol 85:e00935–e00919
Koczan JM, McGrath MJ, Zhao Y, Sundin GW (2009) Contribution of Erwinia amylovora exopolysaccharides amylovoran and Levan to biofilm formation: implications in pathogenicity. Phytopathology 99:1237–1244
Koczan JM, Lenneman BR, McGrath MJ, Sundin GW (2011) Cell surface attachment structures contribute to biofilm formation and xylem colonization by Erwinia amylovora. Appl Environ Microbiol 77:7031–7039
Lai JL, Tang DJ, Liang YW, Zhang R, Chen Q, Qin ZP, Ming ZH, Tang JL (2018) The RNA chaperone Hfq is important for the virulence, motility and stress tolerance in the phytopathogen Xanthomonas campestris. Environ Microbiol Rep 10:542–554
Lowe-Power TM, Hendrich CG, von Roepenack-Lahaye E, Li B, Wu D, Mitra R, Dalsing BL, Ricca P, Naidoo J, Cook D, Jancewicz A (2018a) Metabolomics of tomato xylem sap during bacterial wilt reveals Ralstonia solanacearum produces abundant putrescine, a metabolite that accelerates wilt disease. Environ Microbiol 20:1330–1349
Lowe-Power TM, Khokhani D, Allen C (2018b) How Ralstonia solanacearum exploits and thrives in the flowing plant xylem environment. Trends Microbiol 26:929–942
Lu XH, An SQ, Tang DJ, McCarthy Y, Tang JL, Dow JM, Ryan RP (2012) RsmA regulates biofilm formation in Xanthomonas campestris through a regulatory network involving cyclic di-GMP and the Clp transcription factor. PLoS One 7
Meng Y, Li Y, Galvani CD, Hao G, Turner JN, Burr TJ, Hoch HC (2005) Upstream migration of Xylella fastidiosa via pilus-driven twitching motility. J Bacteriol 187:5560–5567
Miller TD, Schroth MN (1972) Monitoring the epiphytic population of Erwinia amylovora. Phytopathology 62:1175–1182
Mina IR, Jara NP, Criollo JE, Castillo JA (2019) The critical role of biofilms in bacterial vascular plant pathogenesis. Plant Pathol 68:1439–1447
Momol MT, Norelli JL, Piccioni DE, Momol EA, Gustafson HL, Cummins JN, Aldwinckle HS (1998) Internal movement of Erwinia amylovora through symptomless apple scion tissues into the rootstock. Plant Dis 82:646–650
Monds RD, O’Toole GA (2009) The developmental model of microbial biofilms: ten years of a paradigm up for review. Trends Microbiol 17:73–87
Navarrete F, De La Fuente L (2015) Zinc detoxification is required for full virulence and modification of the host leaf ionome by Xylella fastidiosa. Molecular Plant Microbe Interactions 28:497–507
Newman KL, Almeida RP, Purcell AH, Lindow SE (2003) Use of a green fluorescent strain for analysis of Xylella fastidiosa colonization of Vitis vinifera. Applied and Environmental Microbioogy 69:7319–7327
Nimtz M, Mort A, Domke T, Wray V, Zhang Y, Qiu F, Coplin D, Geider K (1996) Structure of amylovoran, the capsular exopolysaccharide from the fire blight pathogen Erwinia amylovora. Carbohydr Res 287:59–76
Nino-Liu DO, Ronald PC, Bogdanove AJ (2006) Xanthomonas oryzae pathovars: model pathogens of a model crop. Mol Plant Pathol 7:303–324
O'Toole GA, Kolter R (1998) Flagellar and twitching motility are necessary for Pseudomonas aeruginosa biofilm development. Mol Microbiol 30:295–304
Peeters N, Guidot A, Vailleau F, Valls M (2013) Ralstonia solanacearum, a widespread bacterial plant pathogen in the post-genomic era. Mol Plant Pathol 14:651–662
Pfeilmeier S, Saur IML, Rathjen JP, Zipfel C, Malone JG (2016) High levels of cyclic-di-GMP in plant-associated Pseudomonas correlate with evasion of plant immunity. Mol Plant Pathol 17:521–531
Pompili V, Dalla Costa L, Piazza S, Pindo M, Malnoy M (2020) Reduced fire blight susceptibility in apple cultivars using a high-efficiency CRISPR/Cas9-FLP/FRT-based gene editing system. Plant Biotechnol J 18:845–858
Prigent-Combaret C, Prensier G, Le Thi TT, Vidal O, Lejeune P, Dorel C (2000) Developmental pathway for biofilm formation in curli-producing Escherichia coli strains: role of flagella, curli and colanic acid. Environ Microbiol 2:450–464
Rezzonico F, Duffy B (2007) The role of luxS in the fire blight pathogen Erwinia amylovora is limited to metabolism and does not involve quorum sensing. Molecular Plant Microbe Interactions 20:1284–1297
Roper MC (2011) Pantoea stewartii subsp. stewartii: lessons learned from a xylem-dwelling pathogen of sweet corn. Mol Plant Pathol 12:628–637
Rudolph KW, Gross M, Ebrahim-Nesbat F, Nöllenburg M, Zomorodian A, Wydra K, Neugebauer M, Hettwer U, El-Shouny W, Sonnenberg B, Klement Z (1994) The role of extracellular polysaccharides as virulence factors for phytopathogenic pseudomonads and xanthomonads. Molecular Mechanisms of Bacterial Virulence:357–378
Ryan RP, Fouhy Y, Lucey JF, Jiang BL, He YQ, Feng JX, Tang JL, Dow JM (2007) Cyclic di-GMP signaling in the virulence and environmental adaptation of Xanthomonas campestris. Mol Microbiol 63:429–442
Salt DE, Baxter I, Lahner B (2008) Ionomics and the study of the plant ionome. Annu Rev Plant Biol 59:709–733
Shin GY, Schachterle JK, Shyntum DY, Moleleki LN, Coutinho TA, Sundin GW (2019) Functional characterization of a global virulence regulator Hfq and identification of Hfq-dependent sRNAs in the plant pathogen Pantoea ananatis. Front Microbiol 10:2075
Slack SM, Zeng Q, Outwater CA, Sundin GW (2017) Microbiological examination of Erwinia amylovora exopolysaccharide ooze. Phytopathology 107:403–411
Suhayda CG, Goodman RN (1981a) Infection courts and systemic movement of P-32 laveled Erwinia amylovora in apple petioles and stems. Phytopathology 71:656–660
Suhayda CG, Goodman RN (1981b) Early proliferation and migration and subsequent xylem occlusion by Erwinia amylovora and the fate of its extracellular polysaccharide (EPS) in apple shoots. Phytopathology 71:697–707
Tabei H, Mukoo H (1960) Anatomical studies of Rice plant leaves affected with bacterial leaf blight, in particular reference to the structure of water exudation system. Bulletin of the National Institute of Agricultural Sciences, Tokyo 11:37–43
Thomson SV, Gouk SC (2003) Influence of age of apple flowers on growth of Erwinia amylovora and biological control agents. Plant Dis 87:502–509
Vasse J, Frey P, Trigalet A (1995) Microscopic studies of intercellular infection and protoxylem invasion of tomato roots by Pseudomonas solanacearum. Molecular Plant Microbe Interactions 8:241–251
Vogt I, Wohner T, Richter K, Flachowsky H, Sundin GW, Wensing A, Savory EA, Geider K, Day B, Hanke M-V, Peil A (2013) Gene-for-gene relationship in the host-pathogen system Malus x robusta 5 – Erwinia amylovora. New Phytol 197:1262–1275
Wohner TW, Richter K, Sundin GW, Zhao Y, Stockwell VO, Sellmann J, Flachowsky H, Hanke M-V, Peil A (2018) Inoculation of Malus genotypes with a set of Erwinia amylovora strains indicates a gene-for-gene relationship between the effector gene eop1 and both Malus floribunda 821 and Malus ‘Evereste’. Plant Pathol 67:938–947
Wright KJ, Seed PC, Hultgren SJ (2005) Uropathogenic Escherichia coli flagella aid in efficient urinary tract colonization. Infect Immun 73:7657–7668
Zeng Q, Sundin GW (2014) Genome-wide identification of Hfq-regulated small RNAs in the fire blight pathogen Erwinia amylovora discovered small RNAs with virulence regulatory function. BMC Genomics 15:414
Zeng Q, McNally RR, Sundin GW (2013) Global small RNA chaperone Hfq and regulatory small RNAs are important virulence regulators in Erwinia amylovora. J Bacteriol 195:1706–1717
Zhao YF, Sundin GW (2017) Exploring linear and cyclic (di)-nucleotides as messengers for regulation of T3SS and biofilm formation in Erwinia amylovora. J Plant Pathol 99:25–35
Acknowledgments
Funding for the writing of this review was provided by Michigan State University AgBioResearch. Roshni Kharadi is a Michigan State University Plant Science Initiative graduate fellow.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Kharadi, R.R., Sundin, G.W. Dissecting the process of xylem colonization through biofilm formation in Erwinia amylovora. J Plant Pathol 103 (Suppl 1), 41–49 (2021). https://doi.org/10.1007/s42161-020-00635-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s42161-020-00635-x