Medeiros Ian D, Mazur Edyta, Miadlikowska Jolanta, Flakus Adam, Rodriguez-Flakus Pamela, Pardo-De la Hoz Carlos J, Cieślak Elżbieta, Śliwa Lucyna, Lutzoni François
Department of Biology, Duke University, Durham, NC, United States.
W. Szafer Institute of Botany, Polish Academy of Sciences (PAS), Kraków, Poland.
Front Microbiol. 2021 Dec 20;12:774839. doi: 10.3389/fmicb.2021.774839. eCollection 2021.
Shifts in climate along elevation gradients structure mycobiont-photobiont associations in lichens. We obtained mycobiont (lecanoroid Lecanoraceae) and photobiont ( alga) DNA sequences from 89 lichen thalli collected in Bolivia from a ca. 4,700 m elevation gradient encompassing diverse natural communities and environmental conditions. The molecular dataset included six mycobiont loci (ITS, nrLSU, mtSSU, , , and ) and two photobiont loci (ITS, L); we designed new primers to amplify Lecanoraceae and with a nested PCR approach. Mycobionts belonged to s.lat., , , , the "" group, and the "." saligna group. All of these clades except for s.lat. occurred only at high elevation. No single species of Lecanoraceae was present along the entire elevation gradient, and individual clades were restricted to a subset of the gradient. Most Lecanoraceae samples represent species which have not previously been sequenced. clade C, which has not previously been recorded in association with species of Lecanoraceae, predominates at low- to mid-elevation sites. Photobionts from clade I occur at the upper extent of mid-elevation forest and at some open, high-elevation sites, while clades A and S dominate open habitats at high elevation. We did not find clade D. Several putative new species were found in clades A, C, and I. These included one putative species in clade A associated with species growing on limestone at high elevation and a novel lineage sister to the rest of clade C associated with on bark in low-elevation grassland. Three different kinds of photobiont switching were observed, with certain mycobiont species associating with from different major clades, species within a major clade, or haplotypes within a species. Lecanoraceae mycobionts and photobionts exhibit species turnover along the elevation gradient, but with each partner having a different elevation threshold at which the community shifts completely. A phylogenetically defined sampling of a single diverse family of lichen-forming fungi may be sufficient to document regional patterns of diversity and distribution.
沿海拔梯度的气候变化构建了地衣中真菌共生体与光合共生体的关联。我们从玻利维亚采集的89个地衣叶状体中获取了真菌共生体（茶渍型茶渍科）和光合共生体（藻类）的DNA序列，这些叶状体来自约4700米的海拔梯度，涵盖了不同的自然群落和环境条件。分子数据集包括六个真菌共生体位点（ITS、nrLSU、mtSSU、 、 和 ）和两个光合共生体位点（ITS、L）；我们设计了新的引物，采用巢式PCR方法扩增茶渍科的 和 。真菌共生体属于广义的 、 、 、 、“ ”组和“.”柳属组。除广义的 外，所有这些分支仅出现在高海拔地区。茶渍科没有单一物种出现在整个海拔梯度上，各个分支局限于梯度的一个子集。大多数茶渍科样本代表以前未测序的物种。分支C以前未被记录与茶渍科物种相关联，在低至中海拔地区占主导地位。来自分支I的光合共生体出现在中海拔森林的上限以及一些开阔的高海拔地区，而分支A和S在高海拔地区主导开阔栖息地。我们没有发现分支D。在分支A、C和I中发现了几个假定的新物种。其中包括分支A中的一个假定物种，与高海拔石灰岩上生长的 物种相关联，以及分支C其余部分的一个新谱系姐妹，与低海拔草原树皮上的 相关联。观察到三种不同类型的光合共生体转换，某些真菌共生体物种与来自不同主要分支、主要分支内的物种或物种内单倍型的 相关联。茶渍科真菌共生体和 光合共生体沿海拔梯度表现出物种更替，但每个伙伴具有不同的海拔阈值，在该阈值处群落会完全转变。对单个多样化的地衣形成真菌家族进行系统发育定义的采样可能足以记录 多样性和分布的区域模式。
