Data_Sheet_1_Phylogeny and Ecology of Trebouxia Photobionts From Bolivian Lichens.pdf

In the past few years, new phylogenetic lineages in Trebouxia were detected as a result of molecular approaches. These studies included symbiont selectivity in lichen communities, transects along altitudinal gradients at local and global scales and the photobiont diversity in local populations of lichen-forming fungal species. In most of these studies, phylogenetic and haplotype analyses based on the internal transcribed spacer (ITS) locus have continuously allowed the recognition of new monophyletic lineages, which suggests that still numerous undiscovered Trebouxia lineages can be hidden in lichens from unexplored areas, especially in the tropics. Here, we estimated the biodiversity of photobionts in Bolivian Andean vegetation and assessed their specificity. About 403 lichen samples representing 42 genera, e.g., Haematomma, Heterodermia, Hypotrachyna, Lecanora, Lepra, Leucodermia, Parmotrema, Pertusaria, Polyblastidium, and Usnea, containing Trebouxia photobionts, were analyzed. ITS ribosomal DNA (rDNA) and rbcL markers were used. We obtained Trebouxia sequences from Bolivian samples belonging to already described clades A, C, I, and S. Thirty-nine Trebouxia lineages were distinguished within these clades, while 16 were new. To reveal the structure of the community of Bolivian photobionts and their relationships with mycobionts, the comparative effects of climate, altitude, geographical distances, substrate, and habitat type, as well as functional traits of lichens such as growth forms, propagation mode and secondary metabolites, were analyzed. Furthermore, new Bolivian records were included in analysis on a global scale. In our study, the mycobiont genus or even species are the most important factors correlated with photobiont identity. Moreover, we revealed that the community of Bolivian photobionts is shaped by altitude.

近数年来，依托分子生物学手段，研究者在共球藻属（Trebouxia）中发现了诸多全新的系统发育谱系。此类研究涵盖地衣群落中的共生体选择性、局域及全球尺度下沿海拔梯度的样带调查，以及地衣形成真菌物种种群内的光共生生物（photobiont）多样性。
在多数相关研究中，基于内部转录间隔区（internal transcribed spacer, ITS）位点的系统发育与单倍型分析，持续得以识别出新的单系谱系。这表明，在尚未被探索的区域（尤其是热带地区）的地衣中，仍隐藏着大量未被发现的共球藻属谱系。
本研究针对玻利维亚安第斯植被中的光共生生物多样性展开评估，并对其宿主专一性进行分析。本次分析共纳入403份携带共球藻属光共生生物的地衣样本，涉及42个属，包括网衣属（Haematomma）、异芽衣属（Heterodermia）、硬枝衣属（Hypotrachyna）、茶渍属（Lecanora）、鳞网衣属（Lepra）、白盾衣属（Leucodermia）、大叶梅属（Parmotrema）、孔衣属（Pertusaria）、多孢衣属（Polyblastidium）以及松萝属（Usnea）。研究采用核糖体DNA（ribosomal DNA, rDNA）与rbcL基因作为分子标记。
我们从玻利维亚样本中获得的共球藻序列，分属已被描述的进化枝A、C、I及S。在这些进化枝中共区分出39个共球藻谱系，其中16个为全新谱系。
为揭示玻利维亚光共生生物群落的结构及其与真菌共生体（mycobiont）的关联，本研究分析了气候、海拔、地理距离、基质、生境类型等地衣相关变量，以及地衣的生长型、繁殖方式与次生代谢产物等功能性状的比较效应。此外，本研究将全球尺度下的玻利维亚新记录纳入分析范畴。
研究结果表明，真菌共生体的属乃至种水平的分类单元，是与光共生生物身份相关性最强的影响因子。同时，我们发现玻利维亚的光共生生物群落结构受海拔因素塑造。