Plant symbiotic microorganisms in acid sulfate soil: significance in the growth of pioneer plants
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Acid sulfate soil is generated by chemical and microbial oxidization of sulfide-rich minerals/sediments. Although revegetation of the soil is difficult due to low-pH and poor nutrient availability, pioneer plants may adapt to such an extreme environment via associating with mycorrhizal fungi and/or N-fixing bacteria for acquisition of mineral nutrients. In this study, an abandoned quarry in which acid sulfate soil was found was chosen to investigate the influence of soil acidity on the levels of colonization by the microsymbionts, the identities of the microsymbionts that associated with pioneer plants and the dependency of pioneer plants on the microsymbionts. The levels of arbuscular mycorrhizal (AM) colonization in pioneer grass, forbs and legume shrubs grown in the field were assessed, and no significant decline in the levels with an increase in soil acidity was observed. Most of the legume shrubs formed root nodules. Several AM fungi and bradyrhizobia were cultured from the rhizosphere soils of pioneer plants grown in the quarry and identified based on the sequences of the small subunit ribosomal RNA genes. Pot experiments revealed that the microsymbionts isolated from the field significantly promoted the growths of pioneer grasses and legume shrubs in acid sulfate soil at pH 3.4. These results suggest that plant–microbial symbiotic associations play significant roles in the growth of pioneer plants in acid sulfate soil.
KeywordsAcid sulfate soil Arbuscular mycorrhizal fungi Nodule bacteria Pioneer plants
We are grateful to Drs. I. Nioh, K. Saito, M. Satio, M. Abe and Y. Hashimoto for invaluable suggestions, to M. Maesaka, S. Mizuno and Y. Tahara in Nagoya University for technical assistance and to Aichi prefecture for allowing us to collect the samples from the field. This study was supported by Tokai Gakujutsu Shoreikai and the Japan Society for the Promotion of Science (TE).
- Allen MF (1987) Re-establishment of mycorrhizas on Mount St Helens Washington USA migration vectors. Trans Brit Mycol Soc 88:413–417Google Scholar
- Allen MF (1991) The ecology of mycorrhizae. Cambridge University Press, Cambridge, NY, USA, pp 127–140Google Scholar
- An G-H, Miyakawa S, Kawahara A, Osaki M, Ezawa T (2008) Community structures of arbuscular mycorrhizal fungi associated with pioneer grass species Miscanthus sinensis in acid sulfate soils: habitat segregation along pH gradients. Soil Sci Plant Nutri (in press) DOI 10.1111/j.1747-0765.2008.00267.x
- Cline GR, Silvernail AF (1997) Effects of soil acidity on the growth of sericea lespedeza. J Plant Nutri 20:1657–1666Google Scholar
- Oba H, Shinozaki N, Oyaizu H, Tawaraya K, Wagatsuma T, Barraquio WL, Saito M (2004) Arbuscular mycorrhizal fungal communities associated with some pioneer plants in the Lahar area of Mt. Pinatubo, Philippines. Soil Sci Plant Nutri 50:1195–1203Google Scholar
- Requena N, Jimenez I, Toro M, Barea JM (1997) Interactions between plant-growth-promoting rhizobacteria (PGPR), arbuscular mycorrhizal fungi and Rhizobium spp. in the rhizosphere of Anthyllis cytisoides, a model legume for revegetation in mediterranean semi-arid ecosystems. New Phytol 136:667–677CrossRefGoogle Scholar
- Smith SE, Read DJ (1997) Mycorrhizal symbiosis. Academic, San Diego, CA, p 605Google Scholar
- Truog E (1930) The determination of the readily available phosphorus of soils. J Am Soc Agron 22:874–882Google Scholar
- White TJ, Bruns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (eds) PCR protocols: a guide to methods and applications. Academic Press, San Diego, pp 315–322Google Scholar