Growth and pathogenicity characteristics of Ralstonia solanacearum strain RS1100 in long-term stationary phase culture
Tóm tắt
Nonsporulating gram-negative bacteria remain metabolically active and also develop increased resistance to a variety of environmental stresses after exponential growth has stopped and cells enter stationary phase. Ralstonia solanacearum is a nonsporulating gram-negative soil-borne pathogen that causes lethal wilt diseases of many plants around the world. Its growth and pathogenicity characteristics for entering longterm stationary phase were investigated by a prolonged 20- day laboratory culture. The data obtained from viability trial revealed that ≈99% of R. solanacearum strain RS1100 (race 1) died at day 14 in SPA medium and then survivors maintained at ≈105 cfu ml–1 until the 20th day. Binary fission was observed and two modes of death procedures were assumed for growth of R. solanacearum under transmission electronic microscope, nucleoid condensation or nucleoid fragmentation and cytolysis. The latent period for R. solanacearum causing plant wilt prolonged while the cell density reduced gradually. The pathogen retained its aggressiveness at low density as 1.13 × 105 cfu ml–1 at 20th day. Both mucoid and nonmucoid forms of R. solanacearum were coexistent throughout the experiment with varying ratio. The results here confirm that upon entering long-term stationary phase R. solanacearum can survive the stress conditions of nutrient starvation during prolonged stationary phase.
Tài liệu tham khảo
Farrell, M.-J., S.-E. Finkel, 2003: The growth advantage in stationary-phase phenotype conferred by rpoS mutations is dependent on the pH and nutrient environment. J. Bacteriol. 185, 7044–7052.
Finkel, S.-E., R. Kolter, 1999: Evolution of microbial diversity during prolonged starvation. Proc. Natl. Acad. Sci. USA 96, 4023–4027.
Finkel, S.-E., 2006: Long-term survival during stationary phase: evolution and the GASP phenotype. Nature Rev. Microbiol. 4, 113–120.
Genin, S., B. Brito, T.-P. Denny, C. Boucher, 2005: Control of the Ralstonia solanacearum Type III secretion system (Hrp) genes by the global virulence regulator PhcA. FEBS Lett. 579, 2077–2081.
Graham, J., D.-A. Jones, A.-B. Lloyd, 1979: Survival of Pseudomonas solanacearum race 3 in plant debris and in latently infected potato tubers. Phytopathology 69, 1100–1103.
Grey, B.-E., T.-R. Steck, 2001: The viable but nonculturable state of Ralstonia solanacearum may be involved in long-term survival and plant infection. Appl. Environ. Microbiol. 67, 3866–3872.
Hayward, A.-C., 1991: Biology and epidemiology of bacterial wilt caused by Pseudomonas solanacearum. Annu. Rev. Phytopathol. 29, 65–87.
Hersh, M.-N., R.-G. Ponder, P.-J. Hastings, S.-M. Rosenberg, 2004: Adaptive mutation and amplification in Escherichia coli: two pathways of genome adaptation under stress. Res. Microbiol. 155, 352–359.
Kelman, A., 1954: The relationship of pathogenicity in Pseudomonas solanacearum to colony appearance on a tetrazolium medium. Phytopathology 64, 693–695.
Kokalis Burelle, N., S.-S. Gnanamanickam, 2002: Biological control of tomato diseases. In: S.-S. Gnanamanickam (ed.): Biological Control of Crop Diseases. pp. 225–262. Marcel Dekker Inc., New York.
Liu, B., Y.-Z. Lin, Y.-J. Zhu, C.-B. Ge, Y. Cao, 2004: Attenuation characteristies of bacterial-wilt-disease biocontrol strain Anti- 8098A (Bacillus cereus) to Ralstonia solanaceamm. J. Agric. Biotechnol. 12, 322–329 (in Chinese with English Abstract).
Luo, X.-S., C.-X. Fang, J.-Q. Tan, 2007: A new phase of bacteria life cycle: long-term stationary phase. Microbiology 34, 343–346 (in Chinese with English Abstract).
Poussier, S., P. Thoquet, D. Trigalet-Demery, S. Barthet, D. Meyer, M. Arlat, A. Trigalet, 2003: Host plant-dependent phenotypic reversion of Ralstonia solanacearum from nonpathogenic to pathogenic forms via alterations in the phcA gene. Mol. Microbiol. 49, 991–1003.
Shamsuddin, N., A.-B. Lloyd, J. Graham, 1979: Survival of the potato strain of Pseudomonas solanacearum in soil. J. Austr. Inst. Agric. Sci. 44, 212–215.
Shanmugam, V., A. Kumar, Y.-R. Sarma, 2004: Survival of Ralstonia solanacearum in ginger rhizomes stored at different temperatures. Plant Dis. Res. (Ludhiana) 19, 40–43.
Tenaillon, O., E. Denamur, I. Matic, 2004: Evolutionary significance of stress-induced mutagenesis in bacteria. Trends Microbiol. 12, 264–270.
Zambrano, M.-M., Kolter, R., 1996: GASPing for life in stationary phase. Cell 86, 181–184.
Zambrano, M.-M., D.-A. Siegele, M. Almiron, A. Tormo, R. Kolter, 1993: Microbial competition: Escherichia coli mutants that take over stationary phase cultures. Science 259, 1757–1760.
Zhang, C.-L., J.-Y. Hua, D. Wang, H.-Q. Zheng, 1993: Bacterial conservation of Ralstonia solanacearum. Plant Prot. 19, 39–40 (in Chinese).
Zhu, Y.-J., H.-T. Zhou, B. Liu, S.-Q. Zhang, H.-M. Zhu, H. Zhu, J.-M. Che, Y. Cao, 2004: Study on the growing competition relationship between virulent and avirulent strains of Ralstonia solanacearum isolated from tomato. J. Xiamen Univ. (Natural Sci.), 43, 97–101 (in Chinese with English Abstract).