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Microbial communities associated with the root system of wild olives (Olea europaea L. subsp. europaea var. sylvestris) are good reservoirs of bacteria with antagonistic potential against Verticillium dahliae

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Abstract

Wild olive trees, namely oleaster, are considered the ancestor of cultivated olive and a unexplored source of genetic variability that might contain important traits of agronomic and biotechnological interest. The longevity and genetic diversity of oleasters may have favoured selection of specific and well adapted rhizosphere microbial populations that can constitute unique reservoirs of microbial antagonists of Verticillium dahliae, the main soilborne fungal pathogen of olive worldwide. The objective of this present study was to determine the structure and diversity of bacterial communities in the rhizosphere and endosphere of oleaster from 11 havens in Cádiz and Córdoba provinces of Andalusia, southern Spain. To carry out the study we used a multiphasic approach. First, the occurrence and diversity of rhizosphere bacteria was monitored by a cultivation-independent-approach, using fluorescent terminal restriction fragment length polymorphism (FT-RFLP) analyses of amplified 16S rDNA sequences. FT-RFLP patterns revealed a high heterogeneity in the composition of the sampled rhizosphere bacterial communities and suggested the existence of plant genotype-site-specific communities, with each oleaster haven being a unique reservoir of bacterial diversity. Secondly, to investigate the antagonistic potential of these root-associated bacterial populations, a total of 675 bacterial isolates obtained from oleaster rhizosphere and endosphere were screened by dual testing for inhibition of in vitro growth of the highly virulent, olive defoliating pathotype of V. dahliae. Out of 675 tested bacterial isolates, 94 (14%) showed a strong antagonistic activity against a defoliating V. dahliae pathotype. Of the antagonistic bacteria, a slightly lower proportion (12.9% of total bacteria) were inhabitant of the oleaster rhizosphere compared to that in the endosphere (16.5%). The biotechnological potential of those isolates was assessed by in vitro production of different hydrolytic enzymes, indole-1.3-acetic acid (IAA), siderophores, and antimicrobial compounds. Overall, most of bacterial antagonists (58.5 to 78.3%) showed proteolytic, lipolytic, and chitinolytic activity, and produced IAA and siderophores. Finally, analysis of the 16S rDNA gene sequence indicated that most of the 94 bacterial antagonists belong to genera Bacillus (56.4%), Pseudomonas (27.7%), and Paenibacillus (7.4%). Overall, the rhizosphere and endosphere of wild olives were proved as a good reservoir of bacteria antagonists against V. dahliae. Several of those bacteria showing high and broad antagonism potential may therefore be considered for further analyses as promising biocontrol agents against V. dahliae in olive.

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References

  • Ahn TS, Ka JO, Lee GH, Song HG (2007) Revegetation of a lakeside barren area by the application of plant growth-promoting rhizobacteria. J Microbiol 45:171–174

    PubMed  Google Scholar 

  • Altschul SF, Madden TL, Schäffer AA, Zhang J, Zhang Z, Miller W, Lipman DJ (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucl Acids Res 25:3389–3402

    Article  PubMed  CAS  Google Scholar 

  • Álvarez S, Soriano MA, Landa BB, Gómez JA (2007) Soil properties in organic olive groves compared with that in natural areas in a mountainous landscape in southern Spain. Soil Use Manag 23:404–416

    Article  Google Scholar 

  • Angiolillo A, Mencuccini M, Baldoni L (1999) Olive genetic diversity assessed using amplified fragment length polymorphisms. Theor Appl Genet 98:411–421

    Article  CAS  Google Scholar 

  • Baldoni L, Cultrera NG, Mariotti R, Ricciolini C, Arcioni S et al (2009) A consensus list of microsatellite markers for olive genotyping. Mol Breed 24:213–231

    Article  CAS  Google Scholar 

  • Belaj A, Satovic Z, Rallo L, Trujillo I (2002) Genetic diversity and relationships in olive (Olea europaea L.) germplasm collections as determined by randomly amplified polymorphic DNA. Theor Appl Genet 105:638–644

    Article  PubMed  CAS  Google Scholar 

  • Belaj A, Muñoz-Diez C, Baldón L, Porceddu S, Barranco D, Satovic Z (2007) Genetic diversity and population structure of wild olives from North-Western Mediterranean assessed by SSR markers. Ann Bot 100:449–458

    Article  PubMed  CAS  Google Scholar 

  • Belaj A, Muñoz-Diez C, Baldoni L, Satovic Z, Barranco D (2010) Genetic diversity and relationships of wild and cultivated olives at regional level in Spain. Sci Hort 124:323–330

    Article  CAS  Google Scholar 

  • Berg G, Hallmann J (2006) Control of plant pathogenic fungi with bacterial endophytes. In: Schulz BJE, Boyle CJC, Sieber TT (ed) Soil Biology, Vol 9, Part I. Microbial root endophytes. Springler-Verlag Berlin, pp 53–69

  • Berg G, Roskot N, Steidle A, Ebert L, Zock A, Smalla K (2002) Plant-dependent genotypic and phenotypic diversity of antagonistic rhizobacteria isolated from different Verticillium host plants. Appl Environ Microbiol 68:3328–3338

    Article  PubMed  CAS  Google Scholar 

  • Berg G, Krechel A, Ditz M, Sikora RA, Ulrich A, Hallmann J (2005a) Endophytic and ectophytic potato-associated bacterial communities differ in structure and antagonistic function against plant pathogenic fungi. FEMS Microbiol Ecol 51:215–219

    Article  PubMed  CAS  Google Scholar 

  • Berg G, Opelt K, Zachow C, Lottmann H, Götz M, Costa R, Smalla K (2005b) The rhizosphere effect on bacteria antagonistic towards the pathogenic fungus Verticillium differs depending on plant species and site. FEMS Microbiol Ecol 56:250–261

    Google Scholar 

  • Berge O, Heulin T, Achouak W, Richard C, Bally R, Balandreau J (1991) Rahnella aquatilis, a nitrogen-fixing enteric bacterium associated with the rhizosphere of wheat and maize. Can J Microbiol 37:195–203

    Article  Google Scholar 

  • Besnard A, Bervillé A (2000) Multiple origins for the Mediterranean olive (Olea europaea L. subsp. europaea) based upon mitochondrial DNA polymorphisms. C R Acad Sci Paris Sér III 323:173–181

    CAS  Google Scholar 

  • Besnard G, Henry P, Wille L, Cooke D, Chapius E (2007) On the origin of the invasive olives (Olea europaea L., Oleaceae). Heredity 99:608–619

    Article  PubMed  CAS  Google Scholar 

  • Breton C, Pinatel C, Medail F, Bonhomme F (2008) Comparison between classical and Bayesian methods to investigate the history of olive cultivars using SSR-polymorphisms. Plant Sci 175:524–532

    Article  CAS  Google Scholar 

  • Bronzini de Caraffa V, Giannettini J, Gambotti C, Maury J (2002) Genetic relationships between cultivated and wild olives of Corsica and Sardinia using RAPD markers. Euphytica 123:263–271

    Article  CAS  Google Scholar 

  • Calvo J, Calvente V, de Orellano ME, Benuzzio D, Sanz de Tosetti MI (2007) Biological control of postharvest spoilage caused by Penicillium expansum and Botrytis cinerea in apple by using the bacterium Rahnella aquatilis. Int J Food Microbiol 113:251–257. doi:10.1016/j-ijfoodmicro.2006.07.003

    Article  PubMed  Google Scholar 

  • CAP-JA (2009) El olivar Andaluz. Consejería de Agricultura y Pesca (ed). Servicio de Publicaciones y Divulgación: Sevilla, Spain

  • Chen F, Jin-Yum L, Yan-Bin G, Jian-Hui W, Hui-Min W (2009) Biological control of grapevine crown gall: purification and partial characterization of an antibacterial substance produced by Rahnella aquatilis strain HX2. Eur J Plant Pathol 124:427–437

    Article  CAS  Google Scholar 

  • Chernin L, Ismailov Z, Haran S, Chet I (1995) Chitinolytic Enterobacter agglomerans antagonistic to fungal plant pathogens. Appl Environ Microbiol 61:1720–1726

    PubMed  CAS  Google Scholar 

  • Cipriani G, Marrazo MT, Marconi R, Cimato A, Testolin R (2002) Microsatellite markers isolated in olive (Olea europaea L.) are suitable for individual fingerprinting and reveal polymorphism within ancient cultivars. Theor Appl Genet 104:223–228

    Article  PubMed  CAS  Google Scholar 

  • Cocking CE (2003) Endophytic colonization of plant roots by nitrogen-fixing bacteria. Plant Soil 252:169–175

    Article  CAS  Google Scholar 

  • Cook RJ, Thomashow LS, Weller DM, Fujimoto D, Mazzola M et al (1995) Molecular mechanisms of defense by rhizobacteria against root diseases. Proc Natl Acad Sci 92:197–201

    Google Scholar 

  • Correa OS, Montecchia MS, Berti MF, Fernández Ferrari MCF, Pucheu NL, Kerber NL, García AF (2009) Bacillus amyloliquefaciens BNM122, a potential microbial biocontrol agent applied on soybean seeds, causes a minor impact on rhizosphere and soil microbial communities. Appl Soil Ecol 41:185–194

    Article  Google Scholar 

  • De la Rosa R, James C, Tobutt KR (2002) Isolation and characterization of polymorphic microsatellite in olive (Olea europaea L.) and their transferability to other genera in the Oleaceae. Mol Ecol Notes 2:265–267

    Article  Google Scholar 

  • Debode J, De Maeyer K, Perneel M, Pannecoucque J, De Backer G, Höfte M (2007) Biosurfactants are involved in the biological control of Verticillium microesclerotia by Pseudomonas spp. J Appl Microbiol 103:1184–1196

    Article  PubMed  CAS  Google Scholar 

  • Donate-Correa J, León-Barrios M, Pérez-Galdona R (2004) Screening for plant growth-promoting rhizobacteria in Chameacytisus proliferus (tagasate), a forage tree-shrub legume endemic to the Canary Islands. Plant Soil 266:261–272

    Article  CAS  Google Scholar 

  • Dunbar J, Ticknor LO, Kuske CR (2000) Assessment of microbial diversity in four southwestern United States soils by 16S rRNA gene terminal restriction fragment analysis. Appl Environ Microbiol 66:2943–2950

    Article  PubMed  CAS  Google Scholar 

  • Dunbar J, Ticknor LO, Kuske CR (2001) Phylogenetic specificity and reproducibility and new method for analysis of terminal restriction fragment profiles of 16S rRNA genes from bacterial communities. Appl Environ Microbiol 67:190–197

    Article  PubMed  CAS  Google Scholar 

  • Faltin F, Lottman J, Grosch R, Berg G (2004) Strategy to select and assess antagonistic bacteria for biological control of Rhizoactonia solani Kühn. Can J Microbiol 50:811–820

    Article  PubMed  CAS  Google Scholar 

  • Garveba P, van Veen JA, van Elsas JD (2004) Microbial diversity in soil: selection of microbial populations by plant and soil type and implications for disease suppressiveness. Ann Rev Phytopathol 42:243–270

    Article  Google Scholar 

  • Green PS (2002) A revision of Olea L. (Oleaceae). Kew Bulletin 57:91–140

    Article  Google Scholar 

  • Hackl E, Zechmeister-Boltenstern S, Bodrossy L, Sessitsch A (2004) Comparison of diversities and compositions of bacterial populations inhabiting natural forest soils. Appl Environ Microbiol 70:5057–5065

    Article  PubMed  CAS  Google Scholar 

  • Hernesmaa A, Björklöf K, Kiikkilä O, Fritze H, Haahtela K, Romantschuk M (2005) Structure and function of microbial communities in the rhizosphere of Scots pine after tree-felling. Soil Biol Biochem 37:777–785

    Article  CAS  Google Scholar 

  • International Olive Oil Council (2009) World olive oil figures. IOOC. http://www.internationaloliveoil.org/web/aaingles/corp/AreasActivitie/economics/AreasActivitie.html

  • Issaoui M, Mechri B, Echbili A, Dabbou S, Yanghi A, Belguit A, Trigui A, Hammami M (2008) Chemometric characterization of five Tunisian varietals of Olea europaea L. olive fruit according to different maturation indices. J Food Lipids 15:277–296

    Article  CAS  Google Scholar 

  • Jafra S, Przysowa J, Gwizdek-Wisniewska A, van der Wolf JM (2009) Potential of bulb-associated bacteria for biocontrol of hyacinth soft rot caused by Dickeya zeae. J Appl Microbiol 106:268–277

    Article  PubMed  CAS  Google Scholar 

  • Jiménez-Díaz RM, Olivares-García C, Jiménez-Gasco MM, Landa BB, Navas-Cortés JA (2010) Region-wide analysis of genetic diversity in Verticillium dahliae populations infecting olive in Andalusia and agricultural factors influencing the distribution and prevalence of vegetative compatibility groups and pathotypes. Phytopathology. doi:10.1094/PHYTO-07-10-0176

    Google Scholar 

  • Jung S, Park S, Kim D, Kim SB (2008) Denaturing gradient gel electrophoresis analysis of bacterial community profiles in the rhizosphere of cry1AC-carrying Brassica rapa subsp. pekinensis. J Microbiol 46:12–15

    Article  PubMed  CAS  Google Scholar 

  • Kim KY, Jordan D, Krishnan HB (1997) Rahnella aquatilis, a bacterium isolated from soybean rhizosphere can solubilize hidroxyapatite. FEMS Microbiol Lett 153:273–277

    Article  CAS  Google Scholar 

  • King EO, Ward MK, Raney DE (1954) Two simple media for the demonstration of pyocyanin and fluorescein. J Lab Clin Med 44:301–307

    PubMed  CAS  Google Scholar 

  • Landa BB, Mavrodi OV, Raaijmakers JM, McSpadden-Gardener BB, Thomashow LS, Weller DM (2002) Differential ability of genotypes of 2, 4-diacetylphloroglucinol-producing Pseudomonas fluorescens strains to colonize the roots of pea plants. Appl Environ Microbiol 68:3226–3237

    Article  PubMed  CAS  Google Scholar 

  • Landa BB, Mavrodi OV, Schroeder KL, Allende-Molar R, Weller DM (2006) Enrichment and genotypic diversity of phlD-containing fluorescent Pseudomonas spp. in two soils after a century of wheat and flax monoculture. FEMS Microbiol Ecol 55:351–368

    Article  PubMed  CAS  Google Scholar 

  • Landa BB, Montes-Borrego M, Muñoz-Ledesma FJ, Jiménez-Díaz RM (2007) Phylogenetic analysis of Downy mildew pathogens of opium poppy and PCR-based in-planta and seed detection of Peronospora arborescens. Phytopathology 97:1380–1390

    Article  PubMed  CAS  Google Scholar 

  • Lumaret R, Ouazzani N (2001) Ancient wild olives in Mediterranean forests. Nature 413:700

    Article  PubMed  CAS  Google Scholar 

  • Lumaret R, Ouazzani N, Michaud H, Vivier G, Deguilloux MF, Di Giusto F (2004) Allozyme variation of oleaster populations wild olive tree Olea europaea L. in the Mediterranean Basin. Heredity 92:343–351

    Article  PubMed  CAS  Google Scholar 

  • Marilley L, Aragno M (1999) Phylogenetic diversity of bacterial communities differing in degree of proximity of Lolium perene and Trifolium repens roots. Appl Soil Ecol 13:127–136

    Article  Google Scholar 

  • Marschner P, Crowley D, Yang CH (2004) Development of specific rhizosphere bacterial communities in relation to plant species, nutrition and soil type. Plant Soil 261:199–208

    Article  CAS  Google Scholar 

  • Mendes R, Pizzirani-Kleiner AA, Araujo WL, Raaijmakers JM (2007) Diversity of cultivated endophytic bacteria from sugarcane: genetic and biochemical characterization of Burkholderia cepacia complex isolates. Appl Environ Microbiol 73:7259–7267

    Article  PubMed  CAS  Google Scholar 

  • Mercado-Blanco J, Rodríguez-Jurado D, Hervás A, Jiménez-Díaz RM (2004) Suppression of Verticillium wilt in olive planting stocks by root-associated fluorescent Pseudomonas spp. Biol Control 30:474–486

    Article  Google Scholar 

  • Micallef SA, Shiaris MP, Colón-Carmona A (2009) Influence of Arabidiopsis thaliana accessions on rhizobacterial communities and natural variation in root exudates. J Exp Bot 60:1729–1742

    Article  PubMed  CAS  Google Scholar 

  • Muleta D, Assefa F, Granhall U (2007) In vitro antagonism of rhizobacteria isolated from Coffea arabica L. against emerging fungal coffee pathogens. Eng Life Sci 7:577–586

    Article  CAS  Google Scholar 

  • Muleta D, Assefa F, Hjort K, Roos S, Granhall U (2009) Characterization of rhizobacteria isolated from wild Coffea arabica L. Eng Life Sci 9:100–108

    Article  CAS  Google Scholar 

  • Navas-Cortés JA, Landa BB, Mercado-Blanco J, Trapero-Casas JL, Rodríguez-Jurado D, Jiménez-Díaz RM (2008) Spatiotemporal analysis of spread of infections by Verticillium dahliae pathotypes within a high tree density olive orchard in southern Spain. Phytopathology 98:167–180

    Article  PubMed  Google Scholar 

  • Park MS, Jung MS, Lee KO, Do L, Kim SB, Bae KS (2005) Isolation and characterization of bacteria associated with two sand dune plant species, Calystegia soldanella and Elymus mollis. J Microbiol 43:219–227

    PubMed  Google Scholar 

  • Paulin MM, Novinscak A, St-Arnaud M, Goyer C, de Coste NJ, Privé JP, Owen J, Filion M (2009) Transcriptional activity of antifungal metabolite-encoding genes phlD and hcnBC in Pseudomonas spp. using qRT-PCR. FEMS Microbiol Ecol 68:212–222

    Article  PubMed  CAS  Google Scholar 

  • Poonguzhali S, Madhaiyan M, Sa T (2006) Cultivation-dependent characterization of rhizobacterial communities from field grown Chinese cabagge Brassica campestris ssp pekinensis and screening of traits for potential plant growth promotion. Plant Soil 286:167–180

    Article  CAS  Google Scholar 

  • Raaijmakers JM, Weller DM (2001) Exploiting genotyping diversity of 2, 4-diacetylphloroglucinol-producing Pseudomonas spp.: characterization of superior root-colonizing P. fluorescens strain Q8r1–96. Appl Environ Microbiol 67:2545–2554

    Article  PubMed  CAS  Google Scholar 

  • Rosenblueth M, Martínez-Romero E (2006) Bacterial endophytes and their interactions with hosts. MPMI 19:827–837

    Article  PubMed  CAS  Google Scholar 

  • Rubio de Casas R, Balaguer L, Manrique E, Pérez-Corona ME, Vargas P (2002) On the historical presence of the wild olives Olea europaea L. var. sylvestris (Miller) Leh. In the Eurosiberian North of the Iberian Peninsula. Anales Jard Bot Madrid 59:342–344

    Google Scholar 

  • Rubio de Casas R, Besnard G, Schönswetter P, Balaguer L, Vargas P (2006) Extensive gene flow blurs phylogeographic but not phylogenetic signal in Olea europaea L. Theor Appl Genet 113:575–583

    Article  PubMed  CAS  Google Scholar 

  • Rumberger A, Merwin IA, Thies JE (2007) Microbial community development in the rhizopshere of apple trees at replant disease site. Soil Biol Biochem 39:1645–1654

    Article  CAS  Google Scholar 

  • Sarwar M, Kremer RJ (1995) Determination of bacterially derived auxins using a microplate method. Lett Appl Microbiol 20:282–285

    Article  Google Scholar 

  • Schwyn B, Neilands JB (1987) Universal chemical assay for the detection and determination of siderophores. Annal Biochem 160:47–56

    Article  CAS  Google Scholar 

  • Sefc KM, Lopes MS, Mendonça D, Rodriguez Dos Santos M, Machado LD, Machado AD (2000) Identification of microsatellite loci in olive (Olea europaea) and their characterization in Italian and Iberian olive trees. Mol Ecol 9:1171–1193

    Article  PubMed  CAS  Google Scholar 

  • Shannon CE, Weaver W (1963) The mathematical theory of communication. University of Illinois Press, Urbana

    Google Scholar 

  • Uppal AK, El Hadrami A, Adam LR, Tenuta M, Daayf F (2008) Biological control of potato Verticillium wilt under controlled and field conditions using selected bacterial antagonists and plant extracts. Biol Control 44:90–100

    Article  Google Scholar 

  • Vargas P, Kadereit JW (2001) Molecular fringerprinting evidence (ISSR, inter-simple sequence repeats) for a wild status of Olea europaea L. (Oleaceae) in the Eurosiberian North of the Iberian Peninsula. Flora 196:142–152

    Google Scholar 

  • Vassilev N, Vassileva M, Nikolaeva I (2006) Simultaneous P-solubilizing and biocontrol activity of microorganisms: potential and future trends. Appl Microbiol Biotechnol 71:137–144

    Article  PubMed  CAS  Google Scholar 

  • Wang Y, Li Q, Shi J, Lin Q, Chen X, Wu CY (2008) Assessment of microbial activity and bacterial community composition in the rhizosphere of a cooper accumulator and a non-accumulator. Soil Biol Biochem 40:1167–1177

    Article  CAS  Google Scholar 

  • Weisburg WG, Barns SM, Pelletier DA, Lane DJ (1991) 16S Ribosomal DNA amplification for phylogenetic study. J Bacteriol 173:697–703

    PubMed  CAS  Google Scholar 

  • Weller DM, Landa BB, Mavrodi OV, Schroeder KL, de la Fuente L et al (2007) Role of 2, 4-Diacetylphloroglucinol-producing fluorescent Pseudomonas spp. in plant defense. Plant Biol 9:4–20

    Article  PubMed  CAS  Google Scholar 

  • Zohary D, Hopf M (1994) Domestication of plants in the Old World, 2nd edn. Clarendon, Oxford

    Google Scholar 

  • Zohary D, Spiegel-Roy P (1975) Beginning of fruit growing in the old world. Science 187:319–327

    Article  PubMed  CAS  Google Scholar 

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Acknowledgements

This research was supported by grants AGL2008-00344 and HA2008-0014 from ‘Ministerio de Ciencia e Innovación’ of Spain and the European Social Fund. S. Aranda was recipient of a PhD grant from ‘Consejo Nacional de Ciencia y Tecnología’ (CONACYT) México. The authors thank H. Müller from Graz University of Technology for providing helpful comments for antagonistic assays and P. Castillo from IAS-CSIC for providing some samples from wild olives. We also thank J.A. Navas-Cortés from IAS-CSIC for providing helpful comments while reviewing the manuscript.

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  1. Institute for Sustainable Agriculture, Spanish National Research Council (CSIC), Alameda del Obispo, s/n, P.O. Box 4084, 14080, Córdoba, Spain

    Sergio Aranda, Miguel Montes-Borrego, Rafael M. Jiménez-Díaz & Blanca B. Landa

  2. Department of Agronomy, Campus de Rabanales-Edificio Celestino Mutis, University of Córdoba, Carretera de Madrid Km 396, 14071, Córdoba, Spain

    Rafael M. Jiménez-Díaz

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  1. Sergio Aranda
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Aranda, S., Montes-Borrego, M., Jiménez-Díaz, R.M. et al. Microbial communities associated with the root system of wild olives (Olea europaea L. subsp. europaea var. sylvestris) are good reservoirs of bacteria with antagonistic potential against Verticillium dahliae . Plant Soil 343, 329–345 (2011). https://doi.org/10.1007/s11104-011-0721-2

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