Characterization of mycorrhizal fungi isolated from the threatened Cypripedium macranthos in a northern island of Japan: two phylogenetically distinct fungi associated with the orchid
Tóm tắt
We isolated Rhizoctonia-like fungi from populations of the threatened orchid Cypripedium macranthos. In ultrastructural observations of the septa, the isolates had a flattened imperforate parenthesome consisting of two electron-dense membranes bordered by an internal electron-lucent zone, identical to the septal ultrastructure of Rhizoctonia repens (teleomorph Tulasnella), a mycorrhizal fungus of many orchid species. However, hyphae of the isolates did not fuse with those of known tester strains of R. repens and grew less than half as fast as those of R. repens. In phylogenetic analyses, sequences for rDNA and internal transcribed spacer (ITS) regions of the isolates were distinct from those of the taxonomically identified species of Tulasnella. On the basis of the ITS sequences, the isolates clustered into two groups that corresponded exactly with the clades demonstrated for other Cypripedium spp. from Eurasia and North America despite the geographical separation, suggesting high specificity in the Cypripedium–fungus association. In addition, the two phylogenetic groups corresponded to two different plant clones at different developmental stages. The fungi from one clone constituted one group and did not belong to the other fungal group isolated from the other clone. The possibility of switching to a new mycorrhizal partner during the orchid’s lifetime is discussed.
Tài liệu tham khảo
Andersen TF (1996) A comparative taxonomic study of Rhizoctonia sensu lato employing morphological, ultrastructural and molecular methods. Mycol Res 100:1117–1128. doi:10.1016/S0953-7562(96)80224-3
Bidartondo MI, Bruns TD, Wiess M, Segio C, Read DJ (2003) Specialized cheating of the ectomycorrhizal symbiosis by an epiparasitic liverwort. Proc R Soc Lond B Biol Sci 270:835–842. doi:10.1098/rspb.2002.2299
Bidartondo MI, Berghardt B, Gebauer G, Bruns TD, Read DJ (2004) Changing partners in the dark: isotopic and molecular evidence of ectomycorrhizal liaisons between forest orchid and trees. Proc R Soc Lond B Biol Sci 271:1799–1806. doi:10.1098/rspb.2004.2807
Dearnaley JD (2007) Further advances in orchid mycorrhizal research. Mycorrhiza 17:475–486. doi:10.1007/s00572-007-0138-1
Kuninaga S, Natsuaki T, Takeuchi T, Yokosawa R (1997) Sequence variation of the rDNA ITS regions within and between anastomosis groups in Rhizoctonia solani. Curr Genet 32:237–243. doi:10.1007/s002940050272
Ma M, Tan TK, Wong SM (2003) Identification and molecular phylogeny of Epulorhiza isolates from tropical orchids. Mycol Res 107:1041–1049. doi:10.1017/s0953756203008281
McCormick MK, Whigham DF, O’Neill JP (2004) Mycorrhizal diversity in photosynthetic terrestrial orchids. New Phytol 163:425–438. doi:10.1111/j.1469-8137.2004.01114.x
McCormick MK, Whigham DF, Sloan D, O’Malley K, Hodkinson B (2006) Orchid–fungus fidelity: a marriage meant to last? Ecology 87:903–911. doi:10.1890/0012-9658(2006)87[903:OFAMMT]2.0.CO;2
Muir HJ (1989) Germination and mycorrhizal fungus compatibility in European orchids. In: Prichard HW (ed) Modern methods in orchid conservation: the role of physiology ecology and management. Cambridge University Press, Cambridge, UK, pp 39–56
Ogoshi A (1975) Grouping of Rhizoctonia solani Kuhn and their perfect stages. Rev Plant Prot Res 8:93–103
Ogura-Tsujita Y, Yukawa T (2008) Epipactis helleborine shows strong mycorrhizal preference towards ectomycorrhizal fungi with contrasting geographic distributions in Japan. Mycorrhiza 18:331–338. doi:10.1007/s00572-008-0187-0
Otero JT, Ackerman JD, Bayman P (2002) Diversity and host specificity of endophytic Rhizoctonia-like fungi from tropical orchids. Am J Bot 89:1852–1858. doi:10.3732/ajb.89.11.1852
Posada D, Crandall KA (1998) Modeltest: testing the model of DNA substitution. Bioinformatics 14:817–818. doi:10.1093/bioinformatics/14.9.817
Reynolds ES (1963) The use of lead citrate at high pH as an electron-opaque stain for electron microscopy. J Cell Biol 17:208–212. doi:10.1083/jcb.17.1.208
Salazar O, Schneider JHM, Julian MC, Keijer J, Rubio V (1999) Phylogenetic subgrouping of Rhizoctonia solani AG 2 isolates based on ribosomal ITS sequences. Mycologia 91:459–467. doi:10.2307/3761346
Sharon M, Kuninaga S, Hyakumachi M, Naito S, Sneh B (2008) Classification of Rhizoctonia spp. using rDNA-ITS sequence analysis supports the genetic basis of the classical anastomosis grouping. Mycoscience 49:93–114. doi:10.1007/s10267-007-0394-0
Shefferson RP, Weiss M, Kull T, Taylor DL (2005) High specificity generally characterizes mycorrhizal association in rare lady’s slipper orchids, genus Cypripedium. Mol Ecol 14:613–626. doi:10.1111/j.1365-294X.2005.02424.x
Shefferson RP, Taylor DL, Weiss M, Garnica S, McCormick MK, Adams S, Gray HM, McFarland JW, Kull T, Tali K, Yukawa T, Kawahara T, Miyoshi K, Lee YI (2007) The evolutionary history of mycorrhizal specificity among lady’s slipper orchids. Evolution 61–6:1380–1390. doi:10.1111/j.1558-5646.2007.00112.X
Shefferson RP, Kull T, Tali K (2008) Mycorrhizal interactions of orchid colonizing Estonian mine tailings hills. Am J Bot 95:156–164. doi:10.3732/ajb.95.2.156
Shimura H, Koda Y (2005) Enhanced symbiotic germination of Cypripedium macranthos var. rebunense following inoculation after cold treatment. Physiol Plant 123:281–287
Smith SE, Read DJ (1997) Mycorrhizal symbiosis, 2nd edn. Academic, San Diego, CA
Sneh B, Burpee L, Ogoshi A (1991) Identification of Rhizoctonia species. APS, St. Paul, MN
Suárez JP, Weiss M, Abele A, Garnica S, Oberwinkler F, Kottke I (2006) Diverse tulasnelloid fungi from mycorrhizas with epiphytic orchids in Andean cloud forest. Mycol Res 110:1257–1270. doi:10.1016/j.mycres.2006.08.004
Swofford DL (2002) PAUP*: phylogenetic analysis using parsimony (*and other methods), version 4.0b10. Sinauer, Sunderland, MA
Taylor DL, Bruns TD (1997) Independent, specialized invasions of ectomycorrhizal mutualism by two nonphotosynthetic orchids. Proc Natl Acad Sci U S A 94:4510–4515. doi:10.1073/pnas.94.9.4510
Taylor DL, Bruns TD, Leake JR, Read DJ (2002) Mycorrhizal specificity and function in myco-heterotrophic plants. In: van der Hejden MGA, Sanders IR (eds) Mycorrhizal ecology. Springer, Berlin, pp 375–413
Taylor DL, Bruns TD, Szaro TM, Hodges SA (2003) Divergence in mycorrhizal specialization within Hexalectris spicata (Orchidaceae), a nonphotosynthetic desert orchid. Am J Bot 90:1168–1179. doi:10.3732/ajb.90.8.1168
Taylor DL, McCormick MK (2008) Internal transcribed spacer primers and sequences for improved characterization of basidiomycetous orchid mycorrhizas. New Phytol 177:1020–1033. doi:10.1111/j.1469-8137.2007.02320.x
Thompson JD, Higgins DG, Gibson TJ (1994) CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, positions-specific gap penalties and weight matrix choice. Nucleic Acids Res 22:4673–4680. doi:10.1093/nar/22.22.4673
Warcup JH, Talbot PHB (1971) Perfect states of Rhizoctonias associated with orchids II. New Phytol 70:35–40. doi:10.1111/j.1469-8137.1971.tb02506.x
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, San Diego, CA, pp 315–322
Zelmer CD, Currah RS (1995) Ceratorhiza pernacatena and Epulorhiza calendulina spp. nov.: mycorrhizal fungi of terrestrial orchids. Can J Bot 73:1981–1985. doi:10.1139/b95-212