Abstract
Root colonization of beneficial rhizobacteria is critical for their beneficial effects. Quorum sensing (QS) has been reported to affect the colonization of many plant pathogens. However, how QS signals regulate root colonization of beneficial rhizobacteria is unclear. In this study, the QS signal AI-2 synthetase-encoding gene luxS was completely deleted from the genome of the plant beneficial rhizobacterium Bacillus velezensis SQR9, and bioluminescence experiments showed that AI-2 production was blocked. Deletion of luxS reduced biofilm formation, motility, and root colonization of B. velezensis SQR9, while addition of exogenous AI-2 to the mutant restored this phenomenon. These results indicated that AI-2 positively affects the root colonization of B. velezensis SQR9. This study provided new insights for enhancing the colonization of beneficial rhizobacteria.
Key points
• LuxS participated in the synthesis of the quorum sensing signal AI-2 in B. velezensis.
• AI-2 enhanced motility, biofilm formation, and root colonization of B. velezensis.
• AI-2 stimulated the production of γ-polyglutamic acid by B. velezensis.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ashiuchi M (2011) Analytical approaches to poly-γ-glutamate: quantification, molecular size determination, and stereochemistry investigation. J Chromatogr B Anal Technol Biomed Life Sci 879:3096–3101. https://doi.org/10.1016/j.jchromb.2011.03.029
Auger S, Krin E, Aymerich S, Gohar M (2006) Autoinducer 2 affects biofilm formation by Bacillus cereus. Appl Environ Microbiol 72:937–941. https://doi.org/10.1128/AEM.72.1.937
Bassler BL (1999) How bacteria talk to each other: regulation of gene expression by quorum sensing. Curr Opin Microbiol 2:582–587. https://doi.org/10.1016/S1369-5274(99)00025-9
Bassler BL, Wright M, Silverman MR (1994) Multiple signalling systems controlling expression of luminescence in Vibrio harveyi: sequence and function of genes encoding a second sensory pathway. Mol Microbiol 13:273–286. https://doi.org/10.1111/j.1365-2958.1994.tb00422.x
Branda SS, González-Pastor JE, Ben-Yehuda S, Losick R, Kolter R (2001) Fruiting body formation by Bacillus. Proc Natl Acad Sci U S A 98:11621–11626. https://doi.org/10.1073/pnas.191384198
Cao Y, Zhang Z, Ling N, Yuan Y, Zheng X, Shen B, Shen Q (2011) Bacillus subtilis SQR9 can control Fusarium wilt in cucumber by colonizing plant roots. Biol Fertil Soils 47:495–506. https://doi.org/10.1007/s00374-011-0556-2
Chen L, Liu Y, Wu G, Zhang N, Shen Q, Zhang R (2017) Beneficial rhizobacterium Bacillus amyloliquefaciens SQR9 induces plant salt tolerance through spermidine production. Mol Plant-Microbe Interact 30:423–432. https://doi.org/10.1094/MPMI-02-17-0027-R
Feng J, Gao W, Gu Y, Zhang W, Cao M, Song C, Zhang P, Sun M, Yang C, Wang S (2014) Functions of poly-gamma-glutamic acid (γ-PGA) degradation genes in γ-PGA synthesis and cell morphology maintenance. Appl Microbiol Biotechnol 98:6397–6407. https://doi.org/10.1007/s00253-014-5729-0
Goto A, Kunioka M (1992) Biosynthesis and hydrolysis of poly(γ-glutamic acid) from Bacillus subtilis IF03335. Biosci Biotechnol Biochem 56:1031–1035. https://doi.org/10.1271/bbb.56.1031
Hegde M, Englert DL, Schrock S, Cohn WB, Vogt C, Wood TK, Manson MD, Jayaraman A (2011) Chemotaxis to the quorum-sensing signal AI-2 requires the Tsr chemoreceptor and the periplasmic LsrB AI-2-binding protein. J Bacteriol 193:768–773. https://doi.org/10.1128/JB.01196-10
Hoppensack A, Oppermann-Sanio FB, Steinbüchel A (2003) Conversion of the nitrogen content in liquid manure into biomass and polyglutamic acid by a newly isolated strain of Bacillus licheniformis. FEMS Microbiol Lett 218:39–45. https://doi.org/10.1016/S0378-1097(02)01132-1
Hsueh YH, Somers EB, Lereclus D, Wong ACL (2006) Biofilm formation by Bacillus cereus is influenced by PlcR, a pleiotropic regulator. Appl Environ Microbiol 72:5089–5092. https://doi.org/10.1128/AEM.00573-06
Huber B, Riedel K, Hentzer M, Heydorn A, Gotschlich A, Givskov M, Molin S, Eberl L (2001) The cep quorum-sensing system of Burkholderia cepacia H111 controls biofilm formation and swarming motility. Microbiology 147:2517–2528. https://doi.org/10.1099/00221287-147-9-2517
Inoue T, Shingaki R, Hirose S, Waki K, Mori H, Fukui K (2007) Genome-wide screening of genes required for swarming motility in Escherichia coli K-12. J Bacteriol 189:950–957. https://doi.org/10.1128/JB.01294-06
Li S, Zhang N, Zhang Z, Luo J, Shen B, Zhang R, Shen Q (2013) Antagonist Bacillus subtilis HJ5 controls Verticillium wilt of cotton by root colonization and biofilm formation. Biol Fertil Soils 49:295–303. https://doi.org/10.1007/s00374-012-0718-x
Li Q, Li Z, Li X, Xia L, Zhou X, Xu Z, Shao J, Shen Q, Zhang R (2018) FtsEX-CwlO regulates biofilm formation by a plant-beneficial rhizobacterium Bacillus velezensis SQR9. Res Microbiol 169:166–176. https://doi.org/10.1016/j.resmic.2018.01.004
Liang HF, Chen SC, Chen MC, Lee PW, Chen CT, Sung HW (2006) Paclitaxel-loaded poly(γ-glutamic acid)-poly(lactide) nanoparticles as a targeted drug delivery system against cultured HepG2 cells. Bioconjug Chem 17:291–299. https://doi.org/10.1021/bc0502107
Ling H, Kang A, Tan MH, Qi X, Chang MW (2010) The absence of the luxS gene increases swimming motility and flagella synthesis in Escherichia coli K12. Biochem Biophys Res Commun 401:521–526. https://doi.org/10.1016/j.bbrc.2010.09.080
Liu Y, Chen L, Zhang N, Li Z, Zhang G, Xu Y, Shen Q, Zhang R (2016) Plant-microbe communication enhances auxin biosynthesis by a root-associated bacterium, Bacillus amyloliquefaciens SQR9. Mol Plant-Microbe Interact 29:324–330. https://doi.org/10.1094/MPMI-10-15-0239-R
Liu Y, Chen L, Wu G, Feng H, Zhang G, Shen Q, Zhang R (2017) Identification of root-secreted compounds involved in the communication between cucumber, the beneficial Bacillus amyloliquefaciens, and the soil-borne pathogen fusarium oxysporum. Mol Plant-Microbe Interact 30:53–62. https://doi.org/10.1094/MPMI-07-16-0131-R
Lombardía E, Rovetto AJ, Arabolaza AL, Grau RR (2006) A LuxS-dependent cell-to-cell language regulates social behavior and development in Bacillus subtilis. J Bacteriol 188:4442–4452. https://doi.org/10.1128/JB.00165-06
Lugtenberg B, Kamilova F (2009) Plant-growth-promoting rhizobacteria. Annu Rev Microbiol 63:541–556. https://doi.org/10.1146/annurev.micro.62.081307.162918
Merritt J, Qi F, Goodman SD, Anderson MH, Shi W (2003) Mutation of luxS affects biofilm formation in Streptococcus mutans. Infect Immun 71:1972–1979. https://doi.org/10.1128/IAI.71.4.1972
Ritchie SMC, Bachas LG, Olin T, Sikdar SK, Bhattacharyya D (1999) Surface modification of silica- and cellulose-based microfiltration membranes with functional polyamino acids for heavy metal sorption. Langmuir 15:6346–6357. https://doi.org/10.1021/la9814438
Rosenberg E, DeLong EF, Lory S, Stackebrandt E, Thompson F (2012) The prokaryotes: prokaryotic communities and ecophysiology. Prokaryotes Prokaryotic Communities Ecophysiol 2:1–528. https://doi.org/10.1007/978-3-642-30123-0
Schauder S, Shokat K, Surette MG, Bassler BL (2001) The LuxS family of bacterial autoinducers: biosynthesis of a novel quorum-sensing signal molecule. Mol Microbiol 41:463–476. https://doi.org/10.1046/j.1365-2958.2001.02532.x
Shao H, Lamont RJ, Demuth DR (2007) Autoinducer 2 is required for biofilm growth of Aggregatibacter (Actinobacillus) actinomycetemcomitans. Infect Immun 75:4211–4218. https://doi.org/10.1128/IAI.00402-07
Shao J, Li S, Zhang N, Cui X, Zhou X, Zhang G, Shen Q, Zhang R (2015) Analysis and cloning of the synthetic pathway of the phytohormone indole-3-acetic acid in the plant-beneficial Bacillus amyloliquefaciens SQR9. Microb Cell Factories 14:1–13. https://doi.org/10.1186/s12934-015-0323-4
Shyu YS, Hwang JY, Hsu CK (2008) Improving the rheological and thermal properties of wheat dough by the addition of γ-polyglutamic acid. LWT Food Sci Technol 41:982–987. https://doi.org/10.1016/j.lwt.2007.06.015
Sperandio V, Torres AG, Kaper JB (2002) Quorum sensing Escherichia coli regulators B and C (QseBC): a novel two-component regulatory system involved in the regulation of flagella and motility by quorum sensing in E. coli. Mol Microbiol 43:809–821. https://doi.org/10.1046/j.1365-2958.2002.02803.x
Stanley NR, Lazazzera BA (2005) Defining the genetic differences between wild and domestic strains of Bacillus subtilis that affect poly-γ-DL-glutamic acid production and biofilm formation. Mol Microbiol 57:1143–1158. https://doi.org/10.1111/j.1365-2958.2005.04746.x
Vendeville A, Winzer K, Heurlier K, Tang CM, Hardie KR (2005) Making “sense” of metabolism: autoinducer-2, LuxS and pathogenic bacteria. Nat Rev Microbiol 3:383–396. https://doi.org/10.1038/nrmicro1146
Verhamme DT, Murray EJ, Stanley-Wall NR (2009) DegU and Spo0A jointly control transcription of two loci required for complex colony development by Bacillus subtilis. J Bacteriol 91:100–108. https://doi.org/10.1128/JB.01236-08
Wai-Leung NG, Bassler B (2015) Bacterial quorum-sensing network architectures. Annu Rev Genet:197–222. https://doi.org/10.1146/annurev-genet-102108-134304.Bacterial
Wu G, Liu Y, Xu Y, Zhang G, Shen Q, Zhang R (2018) Exploring elicitors of the beneficial rhizobacterium Bacillus amyloliquefaciens SQR9 to induce plant systemic resistance and their interactions with plant signaling pathways. Mol Plant-Microbe Interact 31:560–567. https://doi.org/10.1094/MPMI-11-17-0273-R
Xavier KB, Bassler BL (2003) LuxS quorum sensing: more than just a numbers game. Curr Opin Microbiol 6:191–197. https://doi.org/10.1016/S1369-5274(03)00028-6
Xu S, Yang N, Zheng S, Yan F, Jiang C, Yu Y, Guo J, Chai Y, Chen Y (2017) The spo0A-sinI-sinR regulatory circuit plays an essential role in biofilm formation, nematicidal activities, and plant protection in Bacillus cereus AR156. Mol Plant-Microbe Interact 30:603–619. https://doi.org/10.1094/MPMI-02-17-0042-R
Xue T, Ni J, Shang F, Chen X, Zhang M (2015) Autoinducer-2 increases biofilm formation via an ica- and bhp-dependent manner in Staphylococcus epidermidis RP62A. Microbes Infect 17:345–352. https://doi.org/10.1016/j.micinf.2015.01.003
Yan X, Yu HJ, Hong Q, Li SP (2008) Cre/lox system and PCR-based genome engineering in Bacillus subtilis. Appl Environ Microbiol 74:5556–5562. https://doi.org/10.1128/AEM.01156-08
Yu D, Zhao L, Xue T, Sun B (2012) Staphylococcus aureus autoinducer-2 quorum sensing decreases biofilm formation in an icaR-dependent manner. BMC Microbiol 12:1. https://doi.org/10.1186/1471-2180-12-288
Acknowledgments
We thank Prof. Xiangan Han of Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences for providing us the Vibrio harveyi BB 170 reporter strain.
Funding
This work was funded by the National Natural Science Foundation of China grants 31670113 and 31870096, the National Key R & D Program of China grant 2018YFD0500201.
Author information
Authors and Affiliations
Contributions
RZ and GZ conceived and designed research. QX, DL, and HZ conducted experiments. XD and YL analyzed data. QX and YL wrote the manuscript. All authors read and approved the manuscript.
Corresponding authors
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
This article does not contain any studies with human participants or animals performed by any of the authors.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Electronic supplementary material
ESM 1
(PDF 446 kb).
Rights and permissions
About this article
Cite this article
Xiong, Q., Liu, D., Zhang, H. et al. Quorum sensing signal autoinducer-2 promotes root colonization of Bacillus velezensis SQR9 by affecting biofilm formation and motility. Appl Microbiol Biotechnol 104, 7177–7185 (2020). https://doi.org/10.1007/s00253-020-10713-w
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00253-020-10713-w