Uni-Bayreuth grafik-uni-bayreuth


Ogura-Tsujita, Y; Gebauer, G; Hashimoto, T; Umata, H; Yukawa, T: Evidence for novel and specialised mycorrhizal parasitism: the orchid Gastrodia confusa gains carbon from saprotrophic Mycena, Proceedings of the Royal Society London B, 276, 761-767 (2009), doi:10.1098/rspb.2008.1225
We investigated the physiological ecology of the Asian non-photosynthetic orchid Gastrodia confusa. We revealed its mycorrhizal partners by using molecular identification and identified its ultimate nutritional source by analysing carbon and nitrogen natural stable isotope abundances. Molecular identification using internal transcribed spacer and large subunit nrDNA sequences showed that G. confusa associates with several species of litter- and wood-decomposer Mycena fungi. The carbon and nitrogen isotope signatures of G. confusa were analysed together with photosynthetic plant reference samples and samples of the ectomycorrhizal epiparasite Monotropa uniflora. We found that G. confusa was highly enriched in 13C but not greatly in 15N, while M. uniflora was highly enriched in both 13C and 15N. The 13C and 15N signatures of G. confusa were the closest to those of the fruit bodies of saprotrophic fungi. Our results demonstrate for the first time using molecular and mass-spectrometric approaches that myco-heterotrophic plants gain carbon through parasitism of wood or litter decaying fungi. Furthermore, we demonstrate that, several otherwise free-living non-mycorrhizal, Mycena can be mycorrhizal partners of orchids.

Letzte Änderung 29.01.2013