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Puginier C, Libourel C, Otte J, Skaloud P, Haon M, Grisel S, Petersen M, Berrin JG, Delaux PM, Dal Grande F, Keller J. Phylogenomics reveals the evolutionary origins of lichenization in chlorophyte algae. Nat Commun 2024; 15:4452. [PMID: 38789482 PMCID: PMC11126685 DOI: 10.1038/s41467-024-48787-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 05/10/2024] [Indexed: 05/26/2024] Open
Abstract
Mutualistic symbioses have contributed to major transitions in the evolution of life. Here, we investigate the evolutionary history and the molecular innovations at the origin of lichens, which are a symbiosis established between fungi and green algae or cyanobacteria. We de novo sequence the genomes or transcriptomes of 12 lichen algal symbiont (LAS) and closely related non-symbiotic algae (NSA) to improve the genomic coverage of Chlorophyte algae. We then perform ancestral state reconstruction and comparative phylogenomics. We identify at least three independent gains of the ability to engage in the lichen symbiosis, one in Trebouxiophyceae and two in Ulvophyceae, confirming the convergent evolution of the lichen symbioses. A carbohydrate-active enzyme from the glycoside hydrolase 8 (GH8) family was identified as a top candidate for the molecular-mechanism underlying lichen symbiosis in Trebouxiophyceae. This GH8 was acquired in lichenizing Trebouxiophyceae by horizontal gene transfer, concomitantly with the ability to associate with lichens fungal symbionts (LFS) and is able to degrade polysaccharides found in the cell wall of LFS. These findings indicate that a combination of gene family expansion and horizontal gene transfer provided the basis for lichenization to evolve in chlorophyte algae.
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Affiliation(s)
- Camille Puginier
- Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS, INP, Toulouse, 31320, Castanet-Tolosan, France
| | - Cyril Libourel
- Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS, INP, Toulouse, 31320, Castanet-Tolosan, France
| | - Juergen Otte
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Pavel Skaloud
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-12800, Praha 2, Czech Republic
| | - Mireille Haon
- INRAE, Aix Marseille Université, UMR1163 Biodiversité et Biotechnologie Fongiques (BBF), 13009, Marseille, France
- INRAE, Aix Marseille Université, 3PE Platform, 13009, Marseille, France
| | - Sacha Grisel
- INRAE, Aix Marseille Université, UMR1163 Biodiversité et Biotechnologie Fongiques (BBF), 13009, Marseille, France
- INRAE, Aix Marseille Université, 3PE Platform, 13009, Marseille, France
| | - Malte Petersen
- High Performance Computing & Analytics Lab, University of Bonn, Friedrich-Hirzebruch-Allee 8, 53115, Bonn, Germany
| | - Jean-Guy Berrin
- INRAE, Aix Marseille Université, UMR1163 Biodiversité et Biotechnologie Fongiques (BBF), 13009, Marseille, France
- INRAE, Aix Marseille Université, 3PE Platform, 13009, Marseille, France
| | - Pierre-Marc Delaux
- Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS, INP, Toulouse, 31320, Castanet-Tolosan, France.
| | - Francesco Dal Grande
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
- LOEWE Centre for Translational Biodiversity Genomics (TBG), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
- Department of Biology, University of Padova, Padua, Italy.
| | - Jean Keller
- Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS, INP, Toulouse, 31320, Castanet-Tolosan, France.
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany.
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Touchette D, Gostinčar C, Whyte LG, Altshuler I. Lichen-associated microbial members are prevalent in the snow microbiome of a sub-arctic alpine tundra. FEMS Microbiol Ecol 2023; 99:fiad151. [PMID: 37977855 DOI: 10.1093/femsec/fiad151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/27/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023] Open
Abstract
Snow is the largest component of the cryosphere, with its cover and distribution rapidly decreasing over the last decade due to climate warming. It is imperative to characterize the snow (nival) microbial communities to better understand the role of microorganisms inhabiting these rapidly changing environments. Here, we investigated the core nival microbiome, the cultivable microbial members, and the microbial functional diversity of the remote Uapishka mountain range, a massif of alpine sub-arctic tundra and boreal forest. Snow samples were taken over a two-month interval along an altitude gradient with varying degree of anthropogenic traffic and vegetation cover. The core snow alpine tundra/boreal microbiome, which was present across all samples, constituted of Acetobacterales, Rhizobiales and Acidobacteriales bacterial orders, and of Mycosphaerellales and Lecanorales fungal orders, with the dominant fungal taxa being associated with lichens. The snow samples had low active functional diversity, with Richness values ranging from 0 to 19.5. The culture-based viable microbial enumeration ranged from 0 to 8.05 × 103 CFUs/mL. We isolated and whole-genome sequenced five microorganisms which included three fungi, one alga, and one potentially novel bacterium of the Lichenihabitans genus; all of which appear to be part of lichen-associated taxonomic clades.
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Affiliation(s)
- D Touchette
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, H9X 3V9, Canada
- River Ecosystems Laboratory, ALPOLE, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, CH-1950, Sion, Switzerland
| | - C Gostinčar
- University of Ljubljana, Department of Biology, Biotechnical Faculty, Ljubljana 1000, Slovenia
| | - L G Whyte
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, H9X 3V9, Canada
| | - I Altshuler
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, H9X 3V9, Canada
- MACE Laboratory, ALPOLE, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, CH-1950, Sion, Switzerland
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Pichler G, Muggia L, Carniel FC, Grube M, Kranner I. How to build a lichen: from metabolite release to symbiotic interplay. THE NEW PHYTOLOGIST 2023; 238:1362-1378. [PMID: 36710517 PMCID: PMC10952756 DOI: 10.1111/nph.18780] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/28/2022] [Indexed: 06/18/2023]
Abstract
Exposing their vegetative bodies to the light, lichens are outstanding amongst other fungal symbioses. Not requiring a pre-established host, 'lichenized fungi' build an entirely new structure together with microbial photosynthetic partners that neither can form alone. The signals involved in the transition of a fungus and a compatible photosynthetic partner from a free-living to a symbiotic state culminating in thallus formation, termed 'lichenization', and in the maintenance of the symbiosis, are poorly understood. Here, we synthesise the puzzle pieces of the scarce knowledge available into an updated concept of signalling involved in lichenization, comprising five main stages: (1) the 'pre-contact stage', (2) the 'contact stage', (3) 'envelopment' of algal cells by the fungus, (4) their 'incorporation' into a pre-thallus and (5) 'differentiation' into a complex thallus. Considering the involvement of extracellularly released metabolites in each phase, we propose that compounds such as fungal lectins and algal cyclic peptides elicit early contact between the symbionts-to-be, whereas phytohormone signalling, antioxidant protection and carbon exchange through sugars and sugar alcohols are of continued importance throughout all stages. In the fully formed lichen thallus, secondary lichen metabolites and mineral nutrition are suggested to stabilize the functionalities of the thallus, including the associated microbiota.
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Affiliation(s)
- Gregor Pichler
- Department of BotanyUniversity of InnsbruckSternwartestraße 156020InnsbruckAustria
| | - Lucia Muggia
- Department of Life SciencesUniversity of TriesteVia L. Giorgieri 1034127TriesteItaly
| | | | - Martin Grube
- Institute of BiologyUniversity of GrazHolteigasse 68010GrazAustria
| | - Ilse Kranner
- Department of BotanyUniversity of InnsbruckSternwartestraße 156020InnsbruckAustria
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Puginier C, Keller J, Delaux PM. Plant-microbe interactions that have impacted plant terrestrializations. PLANT PHYSIOLOGY 2022; 190:72-84. [PMID: 35642902 PMCID: PMC9434271 DOI: 10.1093/plphys/kiac258] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/09/2022] [Indexed: 05/30/2023]
Abstract
Plants display a tremendous diversity of developmental and physiological features, resulting from gains and losses of functional innovations across the plant phylogeny. Among those, the most impactful have been undoubtedly the ones that allowed plant terrestrializations, the transitions from an aquatic to a terrestrial environment. Although the embryophyte terrestrialization has been particularly scrutinized, others occurred across the plant phylogeny with the involvement of mutualistic symbioses as a common theme. Here, we review the current pieces of evidence supporting that the repeated colonization of land by plants has been facilitated by interactions with mutualistic symbionts. In that context, we detail two of these mutualistic symbioses: the arbuscular mycorrhizal symbiosis in embryophytes and the lichen symbiosis in chlorophyte algae. We suggest that associations with bacteria should be revisited in that context, and we propose that overlooked symbioses might have facilitated the emergence of other land plant clades.
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Affiliation(s)
- Camille Puginier
- Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS, INP Toulouse, Castanet-Tolosan, 31326, France
| | - Jean Keller
- Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS, INP Toulouse, Castanet-Tolosan, 31326, France
| | - Pierre-Marc Delaux
- Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS, INP Toulouse, Castanet-Tolosan, 31326, France
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Plaszkó T, Szűcs Z, Vasas G, Gonda S. Interactions of fungi with non-isothiocyanate products of the plant glucosinolate pathway: A review on product formation, antifungal activity, mode of action and biotransformation. PHYTOCHEMISTRY 2022; 200:113245. [PMID: 35623473 DOI: 10.1016/j.phytochem.2022.113245] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 05/02/2022] [Accepted: 05/12/2022] [Indexed: 05/05/2023]
Abstract
The glucosinolate pathway, which is present in the order Brassicales, is one of the most researched defensive natural product biosynthesis pathways. Its core molecules, the glucosinolates are broken down upon pathogen challenge or tissue damage to yield an array of natural products that may help plants defend against the stressor. Though the most widely known glucosinolate decomposition products are the antimicrobial isothiocyanates, there is a wide range of other volatile and non-volatile natural products that arise from this biosynthetic pathway. This review summarizes our current knowledge on the interaction of these much less examined, non-isothiocyanate products with fungi. It deals with compounds including (1) glucosinolates and their biosynthesis precursors; (2) glucosinolate-derived nitriles (e.g. derivatives of 1H-indole-3-acetonitrile), thiocyanates, epithionitriles and oxazolidine-2-thiones; (3) putative isothiocyanate downstream products such as raphanusamic acid, 1H-indole-3-methanol (= indole-3-carbinol) and its oligomers, 1H-indol-3-ylmethanamine and ascorbigen; (4) 1H-indole-3-acetonitrile downstream products such as 1H-indole-3-carbaldehyde (indole-3-carboxaldehyde), 1H-indole-3-carboxylic acid and their derivatives; and (5) indole phytoalexins including brassinin, cyclobrassinin and brassilexin. Herein, a literature review on the following aspects is provided: their direct antifungal activity and the proposed mechanisms of antifungal action, increased biosynthesis after fungal challenge, as well as data on their biotransformation/detoxification by fungi, including but not limited to fungal myrosinase activity.
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Affiliation(s)
- Tamás Plaszkó
- Department of Botany, Division of Pharmacognosy, University of Debrecen, Egyetem tér 1, 4032, Debrecen, Hungary; Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032, Debrecen, Hungary.
| | - Zsolt Szűcs
- Department of Botany, Division of Pharmacognosy, University of Debrecen, Egyetem tér 1, 4032, Debrecen, Hungary; Healthcare Industry Institute, University of Debrecen, 4032, Debrecen, Hungary.
| | - Gábor Vasas
- Department of Botany, Division of Pharmacognosy, University of Debrecen, Egyetem tér 1, 4032, Debrecen, Hungary.
| | - Sándor Gonda
- Department of Botany, Division of Pharmacognosy, University of Debrecen, Egyetem tér 1, 4032, Debrecen, Hungary.
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Metabolite Profiling in Green Microalgae with Varying Degrees of Desiccation Tolerance. Microorganisms 2022; 10:microorganisms10050946. [PMID: 35630392 PMCID: PMC9144557 DOI: 10.3390/microorganisms10050946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 11/17/2022] Open
Abstract
Trebouxiophyceae are microalgae occupying even extreme environments such as polar regions or deserts, terrestrial or aquatic, and can occur free-living or as lichen photobionts. Yet, it is poorly understood how environmental factors shape their metabolism. Here, we report on responses to light and temperature, and metabolic adjustments to desiccation in Diplosphaera epiphytica, isolated from a lichen, and Edaphochlorella mirabilis, isolated from Tundra soil, assessed via growth and photosynthetic performance parameters. Metabolite profiling was conducted by GC–MS. A meta-analysis together with data from a terrestrial and an aquatic Chlorella vulgaris strain reflected elements of phylogenetic relationship, lifestyle, and relative desiccation tolerance of the four algal strains. For example, compatible solutes associated with desiccation tolerance were up-accumulated in D. epiphytica, but also sugars and sugar alcohols typically produced by lichen photobionts. The aquatic C. vulgaris, the most desiccation-sensitive strain, showed the greatest variation in metabolite accumulation after desiccation and rehydration, whereas the most desiccation-tolerant strain, D. epiphytica, showed the least, suggesting that it has a more efficient constitutive protection from desiccation and/or that desiccation disturbed the metabolic steady-state less than in the other three strains. The authors hope that this study will stimulate more research into desiccation tolerance mechanisms in these under-investigated microorganisms.
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Nazem-Bokaee H, Hom EFY, Warden AC, Mathews S, Gueidan C. Towards a Systems Biology Approach to Understanding the Lichen Symbiosis: Opportunities and Challenges of Implementing Network Modelling. Front Microbiol 2021; 12:667864. [PMID: 34012428 PMCID: PMC8126723 DOI: 10.3389/fmicb.2021.667864] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 04/09/2021] [Indexed: 11/16/2022] Open
Abstract
Lichen associations, a classic model for successful and sustainable interactions between micro-organisms, have been studied for many years. However, there are significant gaps in our understanding about how the lichen symbiosis operates at the molecular level. This review addresses opportunities for expanding current knowledge on signalling and metabolic interplays in the lichen symbiosis using the tools and approaches of systems biology, particularly network modelling. The largely unexplored nature of symbiont recognition and metabolic interdependency in lichens could benefit from applying a holistic approach to understand underlying molecular mechanisms and processes. Together with ‘omics’ approaches, the application of signalling and metabolic network modelling could provide predictive means to gain insights into lichen signalling and metabolic pathways. First, we review the major signalling and recognition modalities in the lichen symbioses studied to date, and then describe how modelling signalling networks could enhance our understanding of symbiont recognition, particularly leveraging omics techniques. Next, we highlight the current state of knowledge on lichen metabolism. We also discuss metabolic network modelling as a tool to simulate flux distribution in lichen metabolic pathways and to analyse the co-dependence between symbionts. This is especially important given the growing number of lichen genomes now available and improved computational tools for reconstructing such models. We highlight the benefits and possible bottlenecks for implementing different types of network models as applied to the study of lichens.
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Affiliation(s)
- Hadi Nazem-Bokaee
- CSIRO Australian National Herbarium, Centre for Australian National Biodiversity Research, National Research Collections Australia, NCMI, Canberra, ACT, Australia.,CSIRO Land and Water, Canberra, ACT, Australia.,CSIRO Synthetic Biology Future Science Platform, Canberra, ACT, Australia
| | - Erik F Y Hom
- Department of Biology and Center for Biodiversity and Conservation Research, The University of Mississippi, University City, MS, United States
| | | | - Sarah Mathews
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Cécile Gueidan
- CSIRO Australian National Herbarium, Centre for Australian National Biodiversity Research, National Research Collections Australia, NCMI, Canberra, ACT, Australia
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Larsen HME, Rasmussen HN. Bark extract influence on spore germination in corticolous lichen Xanthoria parietina in vitro. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01673-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Axenic culture and biosynthesis of secondary compounds in lichen symbiotic fungi, the Parmeliaceae. Symbiosis 2020. [DOI: 10.1007/s13199-020-00719-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Pichler G, Stöggl W, Trippel D, Candotto Carniel F, Muggia L, Ametrano CG, Çimen T, Holzinger A, Tretiach M, Kranner I. Phytohormone release by three isolated lichen mycobionts and the effects of indole-3-acetic acid on their compatible photobionts. Symbiosis 2020; 82:95-108. [PMID: 33223597 PMCID: PMC7671983 DOI: 10.1007/s13199-020-00721-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/14/2020] [Indexed: 01/19/2023]
Abstract
Evidence is emerging that phytohormones represent key inter-kingdom signalling compounds supporting chemical communication between plants, fungi and bacteria. The roles of phytohormones for the lichen symbiosis are poorly understood, particularly in the process of lichenization, i.e. the key events which lead free-living microalgae and fungi to recognize each other, make physical contact and start developing a lichen thallus. Here, we studied cellular and extracellularly released phytohormones in three lichen mycobionts, Cladonia grayi, Xanthoria parietina and Tephromela atra, grown on solid medium, and the effects of indole-3-acetic acid (IAA) on their respective photobionts, Asterochloris glomerata, Trebouxia decolorans, Trebouxia sp. Using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) we found that mycobionts produced IAA, salicylic acid (SA) and jasmonic acid (JA). IAA represented the most abundant phytohormone produced and released by all mycobionts, whereas SA was released by X. parietina and T. atra, and JA was released by C. grayi only. With a half-life of 5.2 days, IAA degraded exponentially in solid BBM in dim light. When IAA was exogenously offered to the mycobionts' compatible photobionts at "physiological" concentrations (as released by their respective mycobionts and accumulated in the medium over seven days), the photobionts' water contents increased up to 4.4%. Treatment with IAA had no effects on the maximum quantum yield of photosystem II, dry mass, and the contents of photosynthetic pigments and α-tocopherol of the photobionts. The data presented may be useful for designing studies aimed at elucidating the roles of phytohormones in lichens.
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Affiliation(s)
- Gregor Pichler
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Wolfgang Stöggl
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Daniela Trippel
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Fabio Candotto Carniel
- Department of Life Sciences, University of Trieste, Via Giorgieri 10, 34127 Trieste, Italy
| | - Lucia Muggia
- Department of Life Sciences, University of Trieste, Via Giorgieri 10, 34127 Trieste, Italy
| | - Claudio Gennaro Ametrano
- Department of Life Sciences, University of Trieste, Via Giorgieri 10, 34127 Trieste, Italy
- Grainger Bioinformatics Center, The Field Museum, 1400 S. Lake Shore Dr, Chicago, IL 60605 USA
| | - Tuğçe Çimen
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
- Department of Molecular Biology and Genetics, İzmir Institute of Technology, 35430 Izmir, Turkey
| | - Andreas Holzinger
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Mauro Tretiach
- Department of Life Sciences, University of Trieste, Via Giorgieri 10, 34127 Trieste, Italy
| | - Ilse Kranner
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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Pichler G, Stöggl W, Candotto Carniel F, Muggia L, Ametrano CG, Holzinger A, Tretiach M, Kranner I. Abundance and Extracellular Release of Phytohormones in Aero-terrestrial Microalgae (Trebouxiophyceae, Chlorophyta) As a Potential Chemical Signaling Source 1. JOURNAL OF PHYCOLOGY 2020; 56:1295-1307. [PMID: 32452544 PMCID: PMC7689701 DOI: 10.1111/jpy.13032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/22/2020] [Indexed: 05/14/2023]
Abstract
Phytohormones are pivotal signaling compounds in higher plants, in which they exert their roles intracellularly, but are also released for cell-to-cell communication. In unicellular organisms, extracellularly released phytohormones can be involved in chemical crosstalk with other organisms. However, compared to higher plants, hardly any knowledge is available on the roles of phytohormones in green algae. Here, we studied phytohormone composition and extracellular release in aero-terrestrial Trebouxiophyceae. We investigated (a) which phytohormones are produced and if they are released extracellularly, and if extracellular phytohormone levels are (b) affected by environmental stimuli, and (c) differ between lichen-forming and non-lichen-forming species. Three free-living microalgae (Apatococcus lobatus, Chloroidium ellipsoideum, and Myrmecia bisecta) and three lichen-forming microalgae (Asterochloris glomerata, Trebouxia decolorans, and Trebouxia sp.) were studied. Algae were grown on solid media and the following cellular phytohormones were identified by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS): indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellin A4 (GA4 ), and zeatin (ZT). Furthermore, IAA, IBA, ABA, jasmonic acid (JA), gibberellin A3 (GA3 ), and GA4 were found to be released extracellularly. IAA and ABA were released by all six species, and IAA was the most concentrated. Phytohormone release was affected by light and water availability, especially IAA in A. glomerata, Trebouxia sp., and C. ellipsoideum. No clear patterns were observed between lichen-forming and non-lichen-forming species. The results are envisaged to contribute valuable baseline information for further studies into the roles of phytohormones in microalgae.
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Affiliation(s)
- Gregor Pichler
- Department of BotanyUniversity of InnsbruckSternwartestraße 156020InnsbruckAustria
| | - Wolfgang Stöggl
- Department of BotanyUniversity of InnsbruckSternwartestraße 156020InnsbruckAustria
| | | | - Lucia Muggia
- Department of Life SciencesUniversity of TriesteVia Giorgieri 1034127TriesteItaly
| | | | - Andreas Holzinger
- Department of BotanyUniversity of InnsbruckSternwartestraße 156020InnsbruckAustria
| | - Mauro Tretiach
- Department of Life SciencesUniversity of TriesteVia Giorgieri 1034127TriesteItaly
| | - Ilse Kranner
- Department of BotanyUniversity of InnsbruckSternwartestraße 156020InnsbruckAustria
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Abstract
ABSTRACT
Lichen symbioses comprise a fascinating relationship between algae and fungi. The lichen symbiotic lifestyle evolved early in the evolution of ascomycetes and is also known from a few basidiomycetes. The ascomycete lineages have diversified in the lichenized stage to give rise to a tremendous variety of morphologies. Their thalli are often internally complex and stratified for optimized integration of algal and fungal metabolisms. Thalli are frequently colonized by specific nonlichenized fungi and occasionally also by other lichens. Microscopy has revealed various ways these fungi interact with their hosts. Besides the morphologically recognizable diversity of the lichen mycobionts and lichenicolous (lichen-inhabiting) fungi, many other microorganisms including other fungi and bacterial communities are now detected in lichens by culture-dependent and culture-independent approaches. The application of multi-omics approaches, refined microscopic techniques, and physiological studies has added to our knowledge of lichens, not only about the taxa involved in the lichen interactions, but also about their functions.
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15
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Lichen photobiont diversity and selectivity at the southern limit of the maritime Antarctic region (Coal Nunatak, Alexander Island). Polar Biol 2016. [DOI: 10.1007/s00300-016-1915-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Athukorala SNP, Piercey-Normore MD. Recognition- and defense-related gene expression at 3 resynthesis stages in lichen symbionts. Can J Microbiol 2015; 61:1-12. [PMID: 25485526 DOI: 10.1139/cjm-2014-0470] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recognition and defense responses are early events in plant-pathogen interactions and between lichen symbionts. The effect of elicitors on responses between lichen symbionts is not well understood. The objective of this study was to compare the difference in recognition- and defense-related gene expression as a result of culture extracts (containing secreted water-soluble elicitors) from compatible and incompatible interactions at each of 3 resynthesis stages in the symbionts of Cladonia rangiferina. This study investigated gene expression by quantitative PCR in cultures of C. rangiferina and its algal partner, Asterochloris glomerata/irregularis, after incubation with liquid extracts from cultures of compatible and incompatible interactions at 3 early resynthesis stages. Recognition-related genes were significantly upregulated only after physical contact, demonstrating symbiont recognition in later resynthesis stages than expected. One of 3 defense-related genes, chit, showed significant downregulation in early resynthesis stages and upregulation in the third resynthesis stage, demonstrating a need for the absence of chitinase early in thallus formation and a need for its presence in later stages as an algal defense reaction. This study revealed that recognition- and defense-related genes are triggered by components in culture extracts at 3 stages of resynthesis, and some defense-related genes may be induced throughout thallus growth. The parasitic nature of the interaction shows parallels between lichen symbionts and plant pathogenic systems.
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Athukorala SNP, Piercey-Normore MD. Effect of temperature and pH on the early stages of interaction of compatible partners of the lichen Cladonia rangiferina (Cladoniaceae). Symbiosis 2014. [DOI: 10.1007/s13199-014-0307-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Meessen J, Sánchez FJ, Sadowsky A, de la Torre R, Ott S, de Vera JP. Extremotolerance and resistance of lichens: comparative studies on five species used in astrobiological research II. Secondary lichen compounds. ORIGINS LIFE EVOL B 2013; 43:501-26. [PMID: 24362711 DOI: 10.1007/s11084-013-9348-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 10/25/2013] [Indexed: 10/25/2022]
Abstract
Lichens, which are symbioses of a fungus and one or two photoautotrophs, frequently tolerate extreme environmental conditions. This makes them valuable model systems in astrobiological research to fathom the limits and limitations of eukaryotic symbioses. Various studies demonstrated the high resistance of selected extremotolerant lichens towards extreme, non-terrestrial abiotic factors including space exposure, hypervelocity impact simulations as well as space and Martian parameter simulations. This study focusses on the diverse set of secondary lichen compounds (SLCs) that act as photo- and UVR-protective substances. Five lichen species used in present-day astrobiological research were compared: Buellia frigida, Circinaria gyrosa, Rhizocarpon geographicum, Xanthoria elegans, and Pleopsidium chlorophanum. Detailed investigation of secondary substances including photosynthetic pigments was performed for whole lichen thalli but also for axenically cultivated mycobionts and photobionts by methods of UV/VIS-spectrophotometry and two types of high performance liquid chromatography (HPLC). Additionally, a set of chemical tests is presented to confirm the formation of melanic compounds in lichen and mycobiont samples. All investigated lichens reveal various sets of SLCs, except C. gyrosa where only melanin was putatively identified. Such studies will help to assess the contribution of SLCs on lichen extremotolerance, to understand the adaptation of lichens to prevalent abiotic stressors of the respective habitat, and to form a basis for interpreting recent and future astrobiological experiments. As most of the identified SLCs demonstrated a high capacity in absorbing UVR, they may also explain the high resistance of lichens towards non-terrestrial UVR.
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Affiliation(s)
- J Meessen
- Institut für Botanik, Heinrich-Heine-Universität (HHU), Universitätsstr.1, 40225, Düsseldorf, Germany,
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Recognition mechanisms during the pre-contact state of lichens: I. Mycobiont-photobiont interactions of the mycobiont of Fulgensia bracteata. Symbiosis 2013. [DOI: 10.1007/s13199-013-0232-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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