Volatiles of bacterial antagonists inhibit mycelial growth of the plant pathogen Rhizoctonia solani
Bacterial antagonists are bacteria that negatively affect the growth of other organisms. Many antagonists inhibit the growth of fungi by various mechanisms, e.g., secretion of lytic enzymes, siderophores and antibiotics. Such inhibition of fungal growth may indirectly support plant growth. Here, we demonstrate that small organic volatile compounds (VOCs) emitted from bacterial antagonists negatively influence the mycelial growth of the soil-borne phytopathogenic fungus Rhizoctonia solani Kühn. Strong inhibitions (99–80%) under the test conditions were observed with Stenotrophomonas maltophilia R3089, Serratia plymuthica HRO-C48, Stenotrophomonas rhizophila P69, Serratia odorifera 4Rx13, Pseudomonas trivialis 3Re2-7, S. plymuthica 3Re4-18 and Bacillus subtilis B2g. Pseudomonas fluorescens L13-6-12 and Burkholderia cepacia 1S18 achieved 30% growth reduction. The VOC profiles of these antagonists, obtained through headspace collection and analysis on GC-MS, show different compositions and complexities ranging from 1 to almost 30 compounds. Most volatiles are species-specific, but overlapping volatile patterns were found for Serratia spp. and Pseudomonas spp. Many of the bacterial VOCs could not be identified for lack of match with mass-spectra of volatiles in the databases.
KeywordsBacterial antagonists Volatile organic compounds Serratia spp. Stenotrophomonas spp. Pseudomonas spp. Staphylococcus epidermidis Burkholderia cepacia Bacillis subtilis Rhizoctonia solani
The authors thank Hella Goschke (University of Rostock) for cultivating the antagonists and R. solani, Prof. Dr. W. Francke (University of Hamburg) for structural investigations of the Serratia odorifera VOC, and Prof. Dr. E. Pichersky (University of Ann Arbor, Michigan, USA) for critical reading the manuscript.
- Arimura G, Ozawa R, Kugimiya S, Takabayashi J, Bohlmann J (2004) Herbivore-induced defense response in a model legume. Two-spotted spider mites induce emission of (E)-β-ocimene and transcript accumulation of (E)-β-ocimene synthase in Lotus japonicus. Plant Physiol 135:1976–1983PubMedCrossRefGoogle Scholar
- Berg G, Ballin G (1994) Bacterial antagonists to Verticillium dahliae. J Phytopathol 141:99–110Google Scholar
- Cook RJ, Tomashow LS, Weller DM, Fujimoto D, Mazzola M, Bangera G, Kim DS (1995) Molecular mechanisms of defense by rhizobacteria against root disease. Proc Natl Acad Sci USA 92:4197–4201Google Scholar
- Denton M, Kerr KG (1998) Microbiological and clinical aspects of infections associated with Stenotrophomonas maltophilia. Clin Microbiol Rev 1:7–80Google Scholar
- Fernando WGD, Ramarathnam R, Krishnamoorthy AS, Savchuk SC (2005) Identification and use of potential bacterial organic antifungal volatiles. Biocontrol 37:955–964Google Scholar
- Gershenzon J, Kreis W (1999) Biochemistry of terpenoids: monoterpenes, sespuiterpenes, diterpenes, sterols, cardiac glycosides and steroid saponins. In: Wink M (ed) Biochemistry of plant secondary metabolism, annual plant reviews. Academic, Sheffield, pp 222–280Google Scholar
- Gupta AM, Gopal KVB, Tilak R (2000) Mechanism of plant growth promotion by rhizobacteria. Ind J Exp Biol 38:856–862Google Scholar
- Haas D, Defago G (2005) Biological control of soil-borne pathogens by fluorescent pseudomonads. Nat Rev Microbiol 10:1–13Google Scholar
- Kalbe C, Marten P, Berg G (1996) Members of the genus Serratia as beneficial rhizobacteria of oilseed rape. Microbiol Res 151:4433–4400Google Scholar
- Kurze S, Bahl H, Dahl R, Berg G (2001) Biological control of fungal strawberry diseases by Serratia plymuthica HRO-C48. Plant Dis 85:529–534Google Scholar
- Sneh B, Jabaji-Hare S, Neate SM, Dijst G (1996) Rhizoctonia species: taxonomy, molecular biology, ecology; pathology and disease control. Kluwer, DordrechtGoogle Scholar
- Zhang YQ, Ren SX, Li HL, Wang YX, Fu G, Yang J, Qin ZQ, Miao YG, Wang WY, Chen RS, Shen Y, Chen Z, Yuan ZH, Zhao GP, Qu D, Danchin A, Wen YM (2003) Genome-based analysis of virulence genes in a non-biofilm-forming Staphylococcus epidermidis strain (ATCC 12228). Mol Microbiol 49:1577–1593PubMedCrossRefGoogle Scholar