石蕊属地衣中担子菌酵母及其他内生真菌多样性研究

地衣是真菌和绿藻或蓝细菌长期演化形成的稳定互惠共生生物。然而，在实验室中，仅用这两个组分来重新创造地衣的尝试从未成功。近来，在多个子囊菌大型地衣类群中发现了第三种共生体担子菌酵母，存在于地衣的外皮层。石蕊属地衣因其分布广泛及形态复杂,而凸显生态重要性，但对其形态建成仍知之甚少。石蕊属地衣中担子菌酵母及其他子囊菌类的内生真菌丰富而独特。本项目中，我们将利用全基因组数据识别石蕊属重要种类地衣体中的各类真菌组分，了解它们在自然居群中的分布情况及丰富程度；通过荧光原位杂交和共聚焦激光扫描显微镜定位地衣体中不同真菌生物组分；分离和培养地衣型真菌和地衣内生真菌；探讨内嵌的担子菌酵母在重建完整地衣体时的作用；通过培养和非培养方法相结合揭示多个石蕊属地衣种类的内生真菌的物种多样性和宿主偏好性；提供内嵌在地衣中的子囊菌和担子菌演化框架；探究地衣型真菌、共生藻类及担子菌酵母共培养机制，实现地衣重建。

Lichens are highly successful and stable mutualistic organisms between fungi and either or both green algae and cyanobacteria. However, attempts in the laboratory to re-create a lichen using only these two partners were never successful. Recently, a third symbiont that builds the outer cortex of the lichen was discovered in several lichen genera, which belongs to Basidiomycete yeast. Although Cladonia is one of the earliest described genera due to its great abundance in nature and prominent morphological features, its morphogenesis is poorly understood. This species-rich genus (about 500 accepted species) is ecologically important due to its wide occurrence and abundant secondary metabolites. The preliminary research mainly based on DNA barcoding genes has shown that the endolichenic fungi associated with cladoniiform species comprise not only a high degree of taxonomic diversity, but also genetic traits and functional diversity that is both unique relative to the endophytes in other biomes, and potential use for antifungal activity. In the project, we are going to identify fungal components in cladoniiform lichen thalli and understand their prevalence in natural populations using hologenomic data, to localize and simultaneously visualize different fungal bionts in lichen thalli by FISH and CLSM, to isolate and culture both the lichenized and endolichenic fungi, to study the physiological function of Basidiomycete yeast in cladoniiform lichen and to re-create the whole cladoniiform lichen, and to reconstruct the multilocus (ITS,partial LSU and MitSSU etc.) phylogeny for the different endolichenic fungal partner which will provide an evolutionary framework for both the ascomycetes and the basidiomycetes embedded in the lichen thalli and will lead to the description of a few new species. Meanwhile, the culture-based and culture-free approaches will be developed to unveil the species diversity, spatial heterogeneity, environmental sensitivity, and host preference of endolichenic fungi associated with some important cladoniiform species at both local and regional scales.