The Diversity of Lichenized Trentepohlioid Algal (Ulvophyceae) Communities is Driven by Fungal Taxonomy and Ecological Factors

Abstract

Trentepohliales are a group of both free‐living and lichenized algae, with most diversity occurring in tropical regions. Recent studies showed that the abundance of lichens with a trentepohlioid photobiont has been increasing in temperate habitats, probably because of global warming, which makes them an interesting study case. A detailed molecular study of the diversity of lichenized Trentepohliales, epiphytic as well as epilithic, was performed in three forests of north‐western Europe. Additional samples of lichens of the Arthoniales order (associating essentially with a trentepohlioid photobiont) from other European regions and from other continents were also sequenced. A total of 195 algal sequences were obtained. Phylogenetic analyses with rbcL and ITS loci were performed and associations between phylogenetic distances of photobionts and ecological factors (substratum, climate or Wirth indices, mycobiont taxonomy, and geographic location) were tested by variation partitioning and phylogenetic signal analyses. The high number of rbcL algal haplotypes found in some lichens or on different substrata revealed that the Trentepohliales diversity in extratropical regions was underestimated. The phylogenetic patterns showed selectivity of some photobionts in their fungal partner choice and vice‐versa, while others were linked with several haplotypes. Photobionts seemed to be less selective than mycobionts. The main factors influencing lichenized algal community were climate and mycobiont species. Coevolution between mycobionts and photobionts as well as switching between free living and lichenized lifestyles appeared to drive the evolution of Trentepohliales and might explain the high cryptic diversity observed, which might be changing in some regions due to climate change.

Independent, structurally distinct transitions to microfruticose growth in the crustose genus Porina (Ostropales, Lecanoromycetes): new isidioid species from south-western Florida

“…The Trentepohlia sequence obtained from the sample L3135 was placed in Clade 31 sensu Borgato et al (2022). This clade also included sequences obtained from lichen samples (species of Enterographa , Opegrapha and Porina leptalea ) from European temperate forests.…”

“…were selected as outgroups, according to Orange et al (2020) and Ertz & Dieterich (2022), for the mtSSU dataset; Porina austroatlantica P.M. McCarthy & Fryday and Porina multipuncta (Coppins & P. James) Ertz, et al were selected as outgroups for the ITS dataset, according to Orange et al (2020), and P. austroatlantica was also set as outgroup for the concatenated ITS + mtSSU dataset. The phylogenetic analyses of the photobiont included the newly generated rbcL sequences and 444 sequences retrieved from NCBI, including the genera Trentepohlia and Printzina , while as outgroups the species Batophora oerstedii , Bornetella nitida, Bryopsis hypnoides , Caulerpa prolifera, Halimeda discoidea , H. opuntia, Polyphysa peniculus and Ulva linta were selected (according to Rindi et al (2009) and Borgato et al (2022)). The alignments were performed using MAFFT v.7 (Katoh et al 2002) with MSA algorithm set on 100 bootstrap replicates and G-ins-I as the substitution model, and then manually adjusted in BioEdit v.7.2.5 (Hall 1999).…”

“…The phylogenetic trees were visualized in TreeView v. 1.6.6 (Page 1996). Species level lineages were recognized as those clades that were monophyletic, fully supported, and represented by more than two samples; they were named according to Orange et al (2020), Ertz & Diederich (2022) and Borgato et al (2022).…”

Coenogonium nimisii – a new isidiate epiphytic lichen similar to Porina rosei

“…Sm. from France in rbcL sequences (Borgato et al 2022). Phycopeltis , which has been repeatedly mentioned as the photobiont of Porina spp.…”