Role of hydrogen peroxide and antioxidative enzymes in Pinus tabulaeformis seedlings inoculated with Amanita vaginata and/or Rhizoctonia solani
The ectomycorrhizal fungus Amanita vaginata can control damping off (Rhizoctonia solani) and promote growth of Pinus tabulaeformis seedlings. The aim of this study was to investigate whether reactive oxygen species and antioxidative enzymes play a role in preventing damping off in ectomycorrhizal roots. Two months after P. tabulaeformis roots were inoculated with A. vaginata, the roots were inoculated with R. solani. During the early stages (2–96 h) of R. solani infection, the quantity and localisation of hydrogen peroxide and the activities of superoxide dismutase and catalase were evaluated. A burst of hydrogen peroxide occurred in ectomycorrhizal roots and in non-ectomycorrhizal roots when attacked by R. solani. In ectomycorrhizal roots, hydrogen peroxide production peaked 12 h after R. solani inoculation, which coincided with an increase in the activity of superoxide dismutase and catalase, whereas in non-ectomycorrhizal roots, hydrogen peroxide production peaked 24 h after R. solani inoculation and did not coincide with changes in superoxide dismutase or catalase activity. The imbalanced activities of superoxide dismutase and catalase might cause excessive accumulation of hydrogen peroxide and consequent damage to cell walls. Electron microscopy revealed that there was a positive correlation between hydrogen peroxide levels and the number of amyloplasts, with seedlings inoculated with A. vaginata and/or R. solani showing higher levels. These results indicated that A. vaginata inoculation enhanced damping off resistance and stimulated seedling growth, which may be due to the activation of a burst of hydrogen peroxide and its scavenging enzymes and the production of biochemical substances such as amyloplasts.
KeywordsAmyloplasts Antioxidative system Biological control Damping off Ectomycorrhiza
This research was supported by the National Natural Science Foundation of China (30730073, 31170567), Program for Changjiang Scholars and Innovative Research Team in University of China (IRT1035) and the Ph. D. Programs Foundation of Education Ministry of China (20100204110033, 20110204130001). We also thank anonymous reviewers for their valuable suggestion to enhance the manuscript.
- Bao, S. D. (2000). Soil and agricultural chemistry analysis (3rd ed.). Beijing, China: China Agriculture Press.Google Scholar
- Branzanti, M. B., Rocca, E., & Pisi, A. (1999). Effect of ectomycorrhizal fungi on chestnut ink disease. Mycorrhiza, 9, 103–109.Google Scholar
- Dumas-Gaudot, E., Gollotte, A., Cordier, C., Gianinazzi, S., & Gianinazzi-Pearson, V. (2000). Modulation of host defence systems. In Y. Kapulnik & D. D. J. Douds (Eds.), Arbuscular mycorrhizas: physiology and function (pp. 173–200). The Netherlands: Kluwer.Google Scholar
- Gao, J. F. (2000). Experimental technology of phytophysiology. Xi’an China: World Book Publishing House.Google Scholar
- Pozo, M. J., Cordier, C., Dumas-Gaudot, E., Gianinazzi, S., Barea, J. M., & Azcón-Aguilar, C. (2002). Localized versus systemic effect of arbuscular mycorrhizal fungi on defence responses to Phytophthora infection in tomato plants. Journal of Experimental Botany, 53, 525–534.PubMedCrossRefGoogle Scholar
- Pozo, M. J., Jung, S. C., López-Ráez, J. A., & Azcón-Aguilar, C. (2010). Impact of arbuscular mycorrhizal symbiosis on plant response to biotic stress: the role of plant defence mechanisms. In H. Koltai & Y. Kapulnik (Eds.), Arbuscular Mycorrhizas: Physiology and Function (pp. 193–207). Springer: Dordrecht, the Netherlands.Google Scholar
- Salzer, P., Hebe, G., Reith, A., Zitterell-Haid, B., Stransky, H., Gaschler, K., et al. (1996). Rapid reactions of spruce cells to elicitors released from the ectomycorrhizal fungus Hebeloma crustuliniforme, and inactivation of these elicitors by extracellular spruce cell enzymes. Planta, 198, 118–126.CrossRefGoogle Scholar
- Sebastiana, M., Figueiredo, A., Acioli, B., Sousa, L., Pessoa, F., Baldé, A., et al. (2009). Identification of plant genes involved on the initial contact between Ectomycorrhizal symbionts (Castanea sativa—European chestnut and Pisolithus tinctorius). European Journal of Soil Biology, 45, 275–282.CrossRefGoogle Scholar
- Vierheilig, H., Steinkellner, S., Khaosaad, T., & Garcia-Garrido, J. M. (2008). mycorrhiza. In A. Varma (Ed.), The biocontrol ffect of mycorrhization on soilborne fungal pathogens and the autoregulation of the AM symbiosis: one mechanism, two effects? (pp. 307–320). Berlin Heidelberg: Springer–Verlag.Google Scholar
- Xavier, L. J. C., & Boyetchko, S. M. (2004). Arbuscular mycorrhizal fungi in plant disease control. In D. K. Arora (Ed.), Fungal biotechnology in agricultural, food, and environmental applications (pp. 183–194). New York: Dekke.Google Scholar