Sambýliskólfsveppir í litskófarætt – eru þeir áður óþekktir framleiðendur mikilvægra náttúruuefna? (KÓLFSVEPPA-FLÉTTUR) - verkefni lokið
Fréttatilkynning verkefnisstjóra
Niðurstöður myndrænu massagreiningarinnar og magnbundinna plöntuefnagreininga auðvelda val ákjósanlegra fléttutegunda og aðgreiningu lífvirkra efnasambanda. Raðgreining DNA í verkefninu hefur varpað ljósi á margbreytileika fléttusambýlisins og bætt skilning okkar á flokkunarfræði og þróunarsögu fléttusveppa.
Fjölbreytni örvera (bakteríur og sveppir) hjá íslenskum fléttum af litskófarætt (Parmeliaceae) var könnuð ásamt staðsetningu lífvirkra efna innan fléttuþalsins. Sérstaklega var leitað eftir kólfsveppum sem sambýlingum og hvort þeir mynduðu lífvirk efni í fléttusambýlinu. Greining á sveppa DNA-röðum leiddu í ljós að einungis 0,26% af heildarmagni kirnisraða tilheyrðu kólfsveppum sem flestir voru af ættkvíslinni Tremella (skjálfi). Fléttumyndandi sveppir af ættkvíslinni Vulpicida (gullinvarp og skyldar tegundir) eru marktækt tengdari kólfsveppum af ættkvíslinni Cyphobasidium en aðrar fléttumyndandi ættkvíslir. Staðsetning andlífis (antibiotic) fléttuefna, þ.e. úsnínsýru (UA) og prótolichesterinsýru (PA) var kortlögð með myndrænni massalitrófsgreiningu. Mest finnst af UA utarlega í fléttuþalinu og vegur 0,5-5 % af þurrvikt fléttunnar og er líka staðsett umhverfis sambýlisþörungana. Þrátt fyrir að PA sé einkum til staðar yst í fléttuþalinu þá er efnið greinilega myndað innan þess. Fléttur sem mynda UA og PA hafa lítið magn af Cyphobasidium sambýlingum sem bendir til að ólíklegt sé að Cyphobasidium framleiði umræddar fléttusýrur. Hluti af genamengi fléttumyndandi sveppa hefur verið sett saman byggt á kirnisröðum sem fengust með “shotgun metagenomic” raðgreiningargögnum sem gera þá kleift að bæta þróunarsögugreiningar fléttumyndandi sveppategunda.
English:
The project explored the microbial diversity of Icelandic lichens in the family Parmeliaceae and spatial distribution of bioactive metabolites in lichens. Particularly, we are interested in the presumable basidiomycetous fungal symbionts – whether they are producing the bioactive metabolites or not. Our fungal metabarcoding results showed that the basidiomycetous fungi account for less than 0.26% of total fungal reads, mostly composed of fungi of the genus Tremella. The lichen-forming fungal genus Vulpicida associates with significantly more Cyphobasidium fungi than other genera. Spatial distribution of antibiotic lichen metabolites, i.e. usnic acid (UA) and protolichesterinic acid (PA), were investigated using imaging mass spectrometry. UA is produced mostly around the outer region on lichen thalli, accounting for 0.5 to 5% lichen and it is also located around the algal symbionts. PA is however produced inside lichen thalli, and tend to be concentrated on the edges of thalli. UA- and PA-producing lichens have few Cyphobasidium fungal symbionts, and therefore they are unlikely produced by Cyphobasidium. Partial lichen-forming fungal genomes have been assembled from shotgun metagenomic sequencing data, which could be used for a more reliable estimation of fungal phylogeny.
Information on how the results will be applied
The results of imaging mass spectrometry and quantitative phytochemical analyses facilitate the selection of lichen taxa and purification of bioactive compounds. High-throughput DNA sequencing sheds light on the complexity of lichen symbiosis and improves our understanding of lichen taxonomy.
A list of the project's outputs
The project has resulted in three published papers in peer-reviewed journals, one Master's degree thesis and three manuscripts in preparation.
Published papers include:
·
Xu
M, Oppong-Danquah E, Wang X, Oddsson S, Abdelrahman A, Pedersen SV, Szomek M,
Gylfason AE, Snorradottir BS, Christensen EA, Tasdemir D, Jameson CJ, Murad S,
Andersson OS, Magnusson KP, de Boer H, Thorsteinsdottir M, Omarsdottir S,
Heidmarsson S, Olafsdottir ES. 2022. Novel methods to characterise spatial
distribution and enantiomeric composition of usnic acids in four Icelandic
lichens. Phytochemistry 200: 113210.
DOI:
10.1016/j.phytochem.2022.113210
·
Xu M,
de Boer H, Olafsdottir ES, Omarsdottir S, Heidmarsson S. 2020. Phylogenetic diversity of the
lichenized algal genus Trebouxia (Trebouxiophyceae, Chlorophyta): a new lineage
and novel insights from fungal-algal association patterns of Icelandic
cetrarioid lichens (Parmeliaceae, Ascomycota). Botanical Journal of the Linnean
Society 194: 460-468.
(DOI: 10.1093/botlinnean/boaa050)
·
Johannsson
F, Cherek P, Xu M, Rolfsson O, Ogmundsdottir H. 2022. The Anti-Proliferative Lichen-Compound
Protolichesterinic Acid Inhibits Oxidative Phosphorylation and Is Processed via
the Mercapturic Pathway in Cancer Cells. In press.
(DOI: 10.1055/a-1579-6454)
Master's degree thesis is:
Gylfason AE. 2019. Content and distribution of usnic acid enantiomers in three Icelandic lichen taxa.
Three manuscripts under preparation include:
· Phylogenetic exploration of metabolite profiles and symbiotic interaction of the lichen-forming fungal genus Nephromopsis (Parmeliaceae, Ascomycota) in Iceland
· Improving the barcoding of herbarium specimens: effective mycobiont-specific PCR primers in the lichen-forming fungal family Parmeliaceae
· New microalgae associated with the lichen-forming ascomycete Cetrariella delisei in Iceland: description of the Trebouxia delisei microalga and its intrathalline diversity
Results from the project have been presented as six oral or two poster presentations in both domestic and international conferences:
2021 | IceBio 2021 – Conference on Biology in Iceland, Reykjavik, Iceland Talk: Chemosystematics and fungal-algal association pattern inspired discovery of a new lichenized algal clade in the genus Trebouxia |
2021 | International Association for Lichenology 9th Symposium, Bonito, Brazil (virtual) Talk: chiral separation, chromatographic modelling, spatial distribution and phylogenetic patterns of usnic acid enantiomers |
2021 | 9th Nordic Natural Product Conference, Oslo, Norway (virtual) Talk: Deciphering the selection of usnic acid-containing lichens for traditional medicines |
2021 | 20th Biomedical and Health Sciences conference, Reykjavik, Iceland Talk: Chiral separation and spatial distribution of usnic acid enantiomers in lichens |
2019 | 8th Nordic Natural Product Conference, Flúðir, Iceland Talk: Ethnolichenology of Iceland Moss (Cetraria islandica): DNA barcoding, chemotaxonomy, phylogeography and future perspectives Poster: How homoplastic is the production of usnic acids? A re-appraisal on enantiomer distribution pattern and its ecological implications |
2019 | 8th International Barcoding of Life Conference, Trondheim, Norway Poster: Extended phylogeny of the lichenized algal genus Trebouxia: insights from chemosystematics and symbiotic pattern of Icelandic cetrarioid lichens |
2019 | 8th Annual ForBio Meeting, Trondheim, Norway Talk: Distribution of usnic acid isomers in the lichenized fungal family Parmeliaceae: their phylogenetic and ecological implications |
Heiti verkefnis: Sambýliskólfsveppir
í litskófarætt – eru þeir áður óþekktir framleiðendur
mikilvægra náttúruuefna? (KÓLFSVEPPA-FLÉTTUR) / Basidiomycete yeasts in
Icelandic cetrarioid lichens: are they hidden natural product reservoirs?
(BASIDIO LICHENS)
Verkefnisstjóri: Maonian Xu, Háskóla
Íslands
Tegund styrks: Nýdoktorsstyrkur
Styrktímabil: 2018-2020
Fjárhæð styrks: 29,874 millj. kr. alls
Tilvísunarnúmer Rannís: 185442