Abstract
Plant organic contamination poses a serious threat to the safety of agricultural products and human health worldwide, and the association of endophytic bacteria with host plants may decrease organic pollutants in planta. In this study, we firstly determined the growth response and biofilm formation of endophytic Pseudomonas sp. Ph6-gfp, and then systematically evaluated the performance of different plant colonization methods (seed soaking (SS), root soaking (RS), leaf painting (LP)) for circumventing the risk of plant phenanthrene (PHE) contamination. After inoculation for 48 h, strain Ph6-gfp grew efficiently with PHE, oxalic acid, or malic acid as the sole sources of carbon and energy. Moreover, strain Ph6-gfp could form robust biofilms in LB medium. In greenhouse hydroponic experiments, strain Ph6-gfp could actively colonize inoculated plants internally, and plants colonized with Ph6-gfp showed a higher capacity for PHE removal. Compared with the Ph6-gfp-free treatment, the accumulations of PHE in Ph6-gfp-colonized plants via SS, RS, and LP were 20.1, 33.1, and 7.1 %, respectively, lower. Our results indicate that inoculating plants with Ph6-gfp could lower the risk of plant PHE contamination. RS was most efficient for improving PHE removal in whole plant bodies by increasing the cell numbers of Ph6-gfp in plant roots. The findings in this study provide an optimized method to strain Ph6-gfp reduce plant PAH residues, which may be applied to agricultural production in PAH-contaminated soil.





References
Afzal M, Yousaf S, Reichenauer TG, Kuffner M, Sessitsch A (2011) Soil type affects plant colonization, activity and catabolic gene expression of inoculated bacterial strains during phytoremediation of diesel. J Hazard Mater 186:1568–1575
Afzal M, Yousaf S, Reichenauer TG, Sessitsch A (2012) The inoculation method affects colonization and performance of bacterial inoculant strains in the phytoremediation of soil contaminated with diesel oil. Int J Phytoremediat 14:35–47
Afzal M, Khan S, Iqbal S, Mirza MS, Khan QM (2013) Inoculation method affects colonization and activity of Burkholderia phytofirmans PsJN during phytoremediation of diesel-contaminated soil. Int J Biodeterior Biodegrad 85:331–336
Afzal M, Khan QM, Sessitsch A (2014) Endophytic bacteria: prospects and applications for the phytoremediation of organic pollutants. Chemosphere 117:232–242
Andria V, Reichenauer TG, Sessitsch A (2009) Expression of alkane monooxygenase (alkB) genes by plant-associated bacteria in the rhizosphere and endosphere of Italian ryegrass (Lolium multiflorum L.) grown in diesel contaminated soil. Environ Pollut 157:3347–3350
Bacilio-Jimenez M, Aguilar-Flores S, Ventura-zapata E, Perez-Campos E, Bouquelet S, Zenteno E (2003) Chemical characterization of root exudates from rice (Oryza sativa) and their effects on the chemotactic response of endophytic bacteria. Plant Soil 249:271–277
Baract T, Weyens N, Oeyen L, Taghavi S, van der Lelie D, Dubin D, Spliet M, Vangronsveld J (2009) Field note: hydraulic containment of a BTEX plume using poplar trees. Int J Phytoremediat 11:416–424
Bhushan B, Samanta SK, Chauhan A, Chakraborti AK, Jain RK (2000) Chemotaxis and degradation of 3-methyl-4-nitrophenol by Ralstonia sp. SJ98. Biochem Biophys Res Commun 275:129–133
Collins C, Fryer M, Grosso A (2006) Plant uptake of non-ionic organic chemicals. Environ Sci Technol 40:45–52
Compant S, Reiter B, Sessitsch A, Nowak J, Clement C, Barka EA (2005) Endophytic colonization of Vitis vinifera L. by plant grown-promoting bacterium Burkholderia sp. strain PsJN. Appl Environ Microbiol 71:1685–1693
De Weert S, Vermeiren H, Mulders IH, Hendrickx N, Bloemberg GV, Vanderleyden J, Mot RD, Lugtenberg BJJ (2002) Flagella-driven chemotaxis towards exudate components is an important trait for tomato root colonization by Pseudomonas fluorescens. Mol Plant Microbe Interact 15:1173–1180
Dong YM, Iniguez AL, Ahmer BMM, Triplett EW (2003) Kinetics and strain specificity of rhizosphere and endophytic colonization by enteric bacteria on seedlings of Medicago sativa and Medicago truncatula. Appl Environ Microbiol 69:1783–1790
Errampalli D, Leung K, Cassidy MB, Kostrzynska M, Blears M, Lee H, Trevors JT (1999) Applications of the green fluorescent protein as a molecular marker in environmental microorganisms. J Microbiol Methods 35:187–199
Ferreira A, Quecine MC, Lacava PT, Oda S, Azevedo JL, Araujo WL (2008) Diversity of endophytic bacteria from Eucalyptus species seeds and colonization of seedlings by Pantoea agglomerans. FEMS Microbiol Lett 287:8–14
Gao YZ, Collins CD (2009) Uptake pathways of polycyclic aromatic hydrocarbons in white clover. Environ Sci Technol 43:6190–6195
Gao YZ, Zhu LZ (2004) Plant uptake, accumulation and translocation of phenanthrene and pyrene in soils. Chemosphere 55:1169–1178
Gao YZ, Xiong W, Ling WT, Wang H, Ren LL, Zhang ZY (2008) Partitioning of polycyclic aromatic hydrocarbons between plant roots and water. Plant Soil 311:201–209
Germaine K, Keogh E, Garcia-Cabellos G, Borremans B, van der Lelie D, Barac T, Oeyen L, Vangronsveld J, Moore FP, Moore ERB, Campbell CD, Ryan D, Dowling DN (2004) Colonisation of poplar trees by gfp expressing bacterial endophytes. FEMS Microbiol Ecol 48:109–118
Germaine KJ, Liu XM, Cabello GG, Hogan JP, Ryan D, Dowling DN (2006) Bacterial endophyte-enhanced phytoremediation of the organochlorine herbicide 2,4-dichlorophenoxyacetic acid. FEMS Microbiol Ecol 57:302–310
Germaine KJ, Keogh E, Ryan D, Dowling DN (2009) Bacterial endophyte-mediated naphthalene phytoprotection and phytoremediation. FEMS Microbiol Lett 296:226–234
Glick BR (2014) Bacteria with ACC deaminase can promote plant growth and help to feed the world. Microbiol Res 169:30–39
Harish S, Kavino M, Kumar N, Balasubramanian P, Samiyappan R (2009) Induction of defense-related proteins by mixtures of plant growth promoting endophytic bacteria against banana bunchy top virus. Biol Control 51:16–25
Iijima S, Washio K, Okahara R, Morikawa M (2009) Biofilm formation and proteolytic activities of Pseudoalteromonas bacteria that were isolated from fish farm sediments. Microb Biotechnol 2:361–369
Ishii S, Koki J, Unno H, Hori K (2004) Two morphological types of cell appendages on a strongly adhesive bacterium Acinetobacter sp. strain Tol 5. Appl Environ Microbiol 70:5026–5029
James EK, Reis VM, Baldani JI, Döbereiner J (1994) Infection of sugar cane by the nitrogen-fixing bacterium Acetobacter diazotrophicus. J Exp Bot 45:757–766
James EK, Gyaneshwar P, Mathan N, Barraquio WL, Reddy PM, Iannetta PPM, Olivares FL, Ladha JK (2002) Infection and colonization of rice seedlings by the plant growth-promoting bacterium Herbaspirillum seropedicae Z67. Mol Plant-Microbe Interact 15:894–906
Khan S, Afzal M, Iqbal S, Khan QM (2013) Plant-bacteria partnerships for the remediation of hydrocarbon contaminated soils. Chemosphere 90:1317–1332
Kvesitadze E, Sadunishvili T, Kvesitadze G (2009) Mechanisms of organic contaminants uptake and degradation in plants. World Acad Sci Eng Technol 55:458–468
Liu J, Liu S, Sun K, Sheng YH, Gu YJ, Gao YZ (2014) Colonization on root surface by a phenanthrene-degrading endophytic bacterium and its application for reducing plant phenanthrene contamination. PLoS One 9, e108249
Lugtenberg BJ, Dekkers L, Bloemberg GV (2001) Molecular determinants of rhizosphere colonization by Pseudomonas. Annu Rev Phytopathol 39:461–490
Mckone TE, Maddalena RL (2007) Plant uptake of organic pollutants from soil: bioconcentration estimates based on models and experiments. Environ Toxicol Chem 26:2494–2504
Nelson EB (2004) Microbial dynamics and interactions in the spermosphere. Annu Rev Phytopathol 42:271–309
Newman LA, Reynolds CM (2005) Bacteria and phytoremediation: new uses for endophytic bacteria in plants. Trends Biotechnol 23:6–8
Porteous Moore F, Barac T, Borremans B, Oeyen L, Vangronsveld J, van der Lelie D, Campbell CD, Moore ERB (2006) Endophytic bacterial diversity in poplar trees growing on a BTEX-contaminated site: the characterisation of isolates with potential to enhance phytoremediation. Syst Appl Microbiol 29:539–556
Ramey BE, Koutsoudis M, von Bodman SB, Fuqua C (2004) Biofilm formation in plant-microbe associations. Curr Opin Microbiol 7:602–609
Ryan RP, Germaine K, Franks A, Ryan DJ, Dowling DN (2008) Bacterial endophytes: recent developments and applications. FEMS Microbiol Lett 278:1–9
Sarand I, Timonen S, Nurmiaho-Lassila EL, Koivula T, Haahtela K (1998) Microbial biofilms and catabolic plasmid harbouring degradative fluorescent pseudomonads in Scots pine mycorrhizospheres developed on petroleum contaminated soil. FEMS Microbiol Ecol 27:115–126
Siciliano SD, Fortin N, Mihoc A, Wisse G, Labelle S, Beaumier D, Ouellette D, Roy R, Whyle LG, Banks MK, Schwab P, Lee K, Greer CW (2001) Selection of specific endophytic bacterial genotypes by plants in response to soil contamination. Appl Environ Microbiol 67:2469–2475
Singh R, Paul D, Jain RK (2006) Biofilms: implication in bioremediation. Trends Microbiol 14:590–600
Strobel G, Daisy B, Castillo U, Harper J (2004) Natural products from endophytic microorganisms. J Nat Prod 67:257–268
Sun K, Liu J, Gao YZ, Jin L, Gu YJ, Wang WQ (2014a) Isolation, plant colonization potential, and phenanthrene degradation performance of the endophytic bacterium Pseudomonas sp. Ph6-gfp. Sci Rep 4:5462
Sun K, Liu J, Jin L, Gao YZ (2014b) Utilizing pyrene-degrading endophytic bacteria to reduce the risk of plant pyrene contamination. Plant Soil 374:251–262
Taghavi S, Barac T, Greenberg B, Borremans B, Vangronsveld J, van der Lelie D (2005) Horizontal gene transfer to endogenous endophytic bacteria from poplar improves phytoremediation of toluene. Appl Environ Microbiol 71:8500–8505
Torres AR, Araújo WL, Coursino L, Rossetto PB, Mondin M, Hungria M, Azevedo JL (2013) Colonization of Madagascar periwinkle (Catharanthus roseus), by endophytes encoding gfp marker. Arch Microbiol 195:483–489
Wang YJ, Xiao M, Geng XL, Liu JY, Chen J (2007) Horizontal transfer of genetic determinants for degradation of phenol between the bacteria living in plant and its rhizosphere. Appl Microbiol Biotechnol 77:733–739
Weyens N, van der Lelie D, Artois T, Smeets K, Taghavi S, Newman L, Carleer R, Vangronsveld J (2009a) Bioaugmentation with engineered endophytic bacteria improves contaminant fate in phytoremediation. Environ Sci Technol 43:9413–9418
Weyens N, van der Lelie D, Taghavi S, Vangronsveld J (2009b) Phytoremediation: plant endophyte partnerships take the challenge. Curr Opin Biotechnol 20:248–254
Weyens N, Boulet J, Adriaensen D, Timmermans JP, Prinsen E, Oevelen SV, D’Hean J, Smeets K, van der Lelie D, Taghavi S, Vangronsveld J (2012) Contrasting colonization and plant growth promoting capacity between wild type and a gfp-derative of the endophyte Pseudomonas putida W619 in hybrid poplar. Plant Soil 356:217–230
Wilson D (1995) Endophyte-the evolution of a term, and clarification of its use and definition. Oikos 73:274–276
Yousaf S, Afzal M, Reichenauer TG, Brady CL, Sessitsch A (2011) Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains. Environ Pollut 159:2675–2683
Zakria M, Ohsako A, Saeki YC, Yamamoto A, Akao S (2007) Colonization and nitrogen-fixing ability of Herbaspirillum sp strain B501 gfp1 and assessment of its growth-promoting ability in cultivated rice. Microbes Environ 22:197–206
Zhu X, Ni X, Liu J, Gao YZ (2014) Application of endophytic bacteria to reduce persistent organic pollutants contamination in plants. CLEAN-Soil Air Water 42:306–310
Acknowledgments
This work was financially supported by the National Science Foundation of China (41201501, 41171380, 51278252, 21477056), the Science Foundation of Jiangsu Province (BK2012370, BK20130030), and the Doctoral Fund of the Ministry of Education of China (20120097120012).
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K. Sun and J. Liu contribute equally to this paper.
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Sun, K., Liu, J., Gao, Y. et al. Inoculating plants with the endophytic bacterium Pseudomonas sp. Ph6-gfp to reduce phenanthrene contamination. Environ Sci Pollut Res 22, 19529–19537 (2015). https://doi.org/10.1007/s11356-015-5128-9
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DOI: https://doi.org/10.1007/s11356-015-5128-9