Complex photobiont diversity in the marine lichen Lichina pygmaea

Abstract

Lichens are a well-known symbiosis between a host mycobiont and eukaryote algal or cyanobacterial photobiont partner(s). Recent studies have indicated that terrestrial lichens can also contain other cryptic photobionts that increase the lichens’ ecological fitness in response to varying environmental conditions. Marine lichens live in distinct ecosystems compared with their terrestrial counterparts because of regular submersion in seawater and are much less studied. We performed bacteria 16S and eukaryote 18S rRNA gene metabarcoding surveys to assess total photobiont diversity within the marine lichen Lichina pygmaea (Lightf.) C. Agardh, which is widespread throughout the intertidal zone of Atlantic coastlines. We found that in addition to the established cyanobacterial photobiont Rivularia, L. pygmaea is also apparently host to a range of other marine and freshwater cyanobacteria, as well as marine eukaryote algae in the family Ulvophyceae (Chlorophyta). We propose that symbiosis with multiple freshwater and marine cyanobacteria and eukaryote photobionts may contribute to the ability of L. pygmaea to survive the harsh fluctuating environmental conditions of the intertidal zone.

A 17-year time-series of fungal environmental DNA from a coastal marine ecosystem reveals long-term seasonal-scale and inter-annual diversity patterns

“…Finally, one other taxon of note is the marine lichen genus Lichina , which has two UK species ( L. pygmaea and L. confinis ). Lichina grow on wave-exposed rocky shores and are abundant along the coastline close to Station L4 all year round [24,25], yet they appear in the time-series dataset only in the spring and mainly between March and May (electronic supplementary material, table S5, figure 4).

Figure 4Abundance patterns of four select fungal genera dominant during ( a ) spring ( Lichina ), ( b ) summer ( Alternaria ), ( c ) autumn ( Hypholoma ) and ( d ) winter ( Phlebia ) as determined by IndVal analysis, representing both marine and terrestrial lineages.

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“…Finally, one other taxon of note is the marine lichen genus Lichina, which has two UK species (L. pygmaea and L. confinis). Lichina grow on wave-exposed rocky shores and are abundant along the coastline close to Station L4 all year round [24,25], yet they appear in the time-series dataset only in the spring and mainly between March and May (electronic supplementary material, table S5, figure 4).…”

Microbial community associated with the crustose lichen Rhizocarpon geographicum L. (DC.) living on oceanic seashore: A large source of diversity revealed by using multiple isolation methods

“…Whereas the 'primary photobiont', Trebouxia, was not recovered, as no specific methodology for such an isolation was used, 'additional photobionts', C. viridis and A. lobatus, were isolated. While the genus Coccomyxa, which can be lichenicolous algae or lichenized photosynthetic partners in lichens (Malavasi et al, 2016) as described in several studies (Cao et al, 2018;Gustavs et al, 2015), displays a wide variety of lifestyles and some of its strains have been identified as extremotolerant and generalists with low nutritional needs (Gustavs et al, 2015), Apatococcus taxon, striking ecological differences with the lichen photobiont (Chrismas et al, 2021;Gustavs et al, 2016), seems to be a specialized and slow-growing alga (Gustavs et al, 2016). It is interesting to note that a strain of Coccomyxa viridis was also isolated from the R. geographicum sample collected 4 years ago.…”

“…It is interesting to note that a strain of Coccomyxa viridis was also isolated from the R. geographicum sample collected 4 years ago. The isolation of such taxa could be explained as a synergistic association in order to counteract the extreme conditions encountered at the sampling sites; the presence of multiple coexisting photobionts with different physiological properties provides an ecological advantage: marine-derived photobionts promote survival in the intertidal zone while freshwaterderived photobionts may allow better photosynthesis during the rain events (Chrismas et al, 2021). Moreover, a recent study related the variation of photobiont diversity depending on the growth stage of the thalli, the geographic location and the habitat.…”

Chemical Composition and In Vitro Antioxidant and Antimicrobial Activities of the Marine Cyanolichen Lichina pygmaea Volatile Compounds

“…Lichens, as symbiotic complex of autotrophic (microalgae, cyanobacteria) and heterotrophic (fungi), are highly adapted to extreme habitats comprising the coastal zones [ 1 ]. Indeed, marine lichens are exposed to an exceptionally range of pressures, due to daily tidal cycles that terrestrial lichens cannot resist [ 2 ]. The lichens growing on littoral and supralittoral zones differ in their resistance to the duration of exposure to salt water and are clearly distinguished taxonomically [ 1 ].…”