Organismische Botanik, Institut für Evolution und Ökologie, Universität Tübingen, Auf der Morgenstelle, Germany.
Fungal Biol. 2011 Sep;115(9):839-51. doi: 10.1016/j.funbio.2011.06.013. Epub 2011 Jul 6.
A total of 35 population samples of the liverwort genera Aneura (A. pinguis) and Riccardia (R. latifrons, R. multifida, and R. palmata) were sampled from diverse habitats and geographical provenances in Germany, Austria, and Switzerland. Light and transmission electron microscopy were used to characterise the morphological features of the associations, and phylogenetic analyses based on internal transcribed spacers (ITS) and the D1/D2 regions of the fungal 28S rDNA were used to address diversity and phylogenetic relationships. By comparing the cellular structures of the plant-fungus interactions, we recognised the following states of fungal colonisation within the thalli: fungus-free, epiphytic, intercellular, and intracellular. Colonising hyphae showed dolipores with imperforate parenthesomes, slime bodies, and multilayered walls. Colonised liverwort cells had pleomorphic nuclei and elongated starch-free chloroplasts with distinctive grana. Our analyses revealed six phylogenetic groups of tulasnelloid fungi associated with liverworts, where major lineages mostly share similar host and/or ecological specialisations. The mode of colonisation of the tulasnelloid mycobionts in Aneura and Riccardia sharing identical fungal sequences is different. Consequently, the mode of colonisation may be host-dependent. Finally, our findings demonstrate that Aneuraceae are model organisms for evolutionary studies of symbiotic associations between liverworts and fungi.
共采集了德国、奥地利和瑞士 35 个地衣门叶苔属（Aneura（A. pinguis））和网萼苔属（Riccardia（R. latifrons、R. multifida 和 R. palmata））的种群样本，这些样本来自不同的生境和地理起源。利用光镜和透射电镜来描述共生体的形态特征，并基于内部转录间隔区（ITS）和真菌 28S rDNA 的 D1/D2 区进行系统发育分析，以解决多样性和系统发育关系问题。通过比较植物-真菌相互作用的细胞结构，我们在叶状体中识别出以下真菌定殖状态：无菌、附生、细胞间和细胞内。定殖的菌丝显示出具有无孔的母质体的桶孔隔膜、粘液体和多层壁。被定殖的叶苔细胞具有多形核和无淀粉的伸长叶绿体，具有独特的基粒。我们的分析揭示了与叶苔共生的 6 个塔鲁内拉真菌类群，其中主要的谱系大多具有相似的宿主和/或生态特化。在共享相同真菌序列的叶苔属和网萼苔属中，塔鲁内拉菌质体的定殖模式不同。因此，定殖模式可能依赖于宿主。最后，我们的研究结果表明，叶苔科是研究叶苔与真菌共生关系进化的模式生物。
