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García-Breijo FJ, Molins A, Reig-Armiñana J, Barreno E. The Tripartite Lichen Ricasolia virens: Involvement of Cyanobacteria and Bacteria in Its Morphogenesis. Microorganisms 2023; 11:1517. [PMID: 37375019 DOI: 10.3390/microorganisms11061517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/31/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Ricasolia virens is an epiphytic lichen-forming fungus mainly distributed in Western Europe and Macaronesia in well-structured forests with ecological continuity that lack eutrophication. It is considered to be threatened or extinct in many territories in Europe (IUCN). Despite its biological and ecological relevance, studies on this taxon are scarce. The thalli are tripartite, and the mycobiont has a simultaneous symbiotic relationship with cyanobacteria and green microalgae, which represent interesting models to analyse the strategies and adaptations resulting from the interactions of lichen symbionts. The present study was designed to contribute to a better understanding of this taxon, which has shown a clear decline over the last century. The symbionts were identified by molecular analysis. The phycobiont is Symbiochloris reticulata, and the cyanobionts (Nostoc) are embedded in internal cephalodia. Light, transmission electron and low-temperature scanning microscopy techniques were used to investigate the thallus anatomy, ultrastructure of microalgae and ontogeny of pycnidia and cephalodia. The thalli are very similar to its closest relative, Ricasolia quercizans. The cellular ultrastructure of S. reticulata by TEM is provided. Non-photosynthetic bacteria located outside the upper cortex are introduced through migratory channels into the subcortical zone by the splitting of fungal hyphae. Cephalodia were very abundant, but never as external photosymbiodemes.
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Affiliation(s)
- Francisco J García-Breijo
- Departamento de Ecosistemas Agroforestales, ETSIAMN, Universitat Politècnica de València, Camino de Vera s/n, 46022 València, Spain
| | - Arantzazu Molins
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
- Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Departamento de Biología, Universitat de les Illes Balears (UIB), Ctra. Valldemossa Km.7., 07122 Palma de Malllorca, Spain
| | - José Reig-Armiñana
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
| | - Eva Barreno
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
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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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3
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Si J, Dong X, Zhang G, Lu H, Tang K, Zhang L, Kong X, Sheng K, Wang J, Zha X, Wang Y. The fucose-specific lectin gene AOL_s00054g276 affects trap formation and nematocidal activity of the nematophagous fungus Arthrobotrys oligospora. FEMS Microbiol Lett 2022; 369:6526307. [PMID: 35142828 DOI: 10.1093/femsle/fnac013] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 12/11/2021] [Accepted: 02/08/2022] [Indexed: 11/14/2022] Open
Abstract
Nematode-trapping fungi are natural enemies of nematodes in nature. Arthrobotrys oligospora, a typical nematode-trapping fungus with a clear genetic background, can capture and infect nematodes by forming adhesive three-dimensional networks. Lectins, a class of glycoproteins containing glycosyl-specific recognition domains, play an important role in biological recognition. However, the fucose-specific lectins have rarely been studied regarding the process of preying on nematodes. In this study, we characterized the biological role of the fucose-specific lectin encoding gene AOL_s00054g276 (g276) in A. oligospora. The gene g276 was first deleted based on homologous recombination, then the phenotype and nematocidal activity of the Δg276 mutant was evaluated. The results showed that the deletion of gene g276 delayed trap formation and weakened its nematocidal activity; however, mycelial growth, conidia production, conidial germination rates, and adaption to environmental stresses were not affected. Our results suggest that the fucose-specific lectin encoding gene g276 might be associated with the morphogenesis of this fungus, and its deletion resulted in a significantly low density of three-dimensional traps (P < 0.05) and a significantly low nematode-tapping efficiency (P < 0.001). These findings provide a basis for further elucidating the mechanism of A. oligospora preying on nematodes and lay a foundation for the development and utilization of fungal-derived lectins for nematode control in future.
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Affiliation(s)
- Jiali Si
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Xinyuan Dong
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Guanghui Zhang
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Hengqian Lu
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Kaijing Tang
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Li Zhang
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Xiaowei Kong
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Kangliang Sheng
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Jingmin Wang
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Xiangdong Zha
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China
| | - Yongzhong Wang
- School of Life Sciences, Anhui University, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China.,Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, Anhui, China
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Lebreton A, Bonnardel F, Dai YC, Imberty A, Martin FM, Lisacek F. A Comprehensive Phylogenetic and Bioinformatics Survey of Lectins in the Fungal Kingdom. J Fungi (Basel) 2021; 7:453. [PMID: 34200153 PMCID: PMC8227253 DOI: 10.3390/jof7060453] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/02/2021] [Accepted: 06/03/2021] [Indexed: 12/28/2022] Open
Abstract
Fungal lectins are a large family of carbohydrate-binding proteins with no enzymatic activity. They play fundamental biological roles in the interactions of fungi with their environment and are found in many different species across the fungal kingdom. In particular, their contribution to defense against feeders has been emphasized, and when secreted, lectins may be involved in the recognition of bacteria, fungal competitors and specific host plants. Carbohydrate specificities and quaternary structures vary widely, but evidence for an evolutionary relationship within the different classes of fungal lectins is supported by a high degree of amino acid sequence identity. The UniLectin3D database contains 194 fungal lectin 3D structures, of which 129 are characterized with a carbohydrate ligand. Using the UniLectin3D lectin classification system, 109 lectin sequence motifs were defined to screen 1223 species deposited in the genomic portal MycoCosm of the Joint Genome Institute. The resulting 33,485 putative lectin sequences are organized in MycoLec, a publicly available and searchable database. These results shed light on the evolution of the lectin gene families in fungi.
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Affiliation(s)
- Annie Lebreton
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China; (A.L.); (Y.-C.D.)
| | - François Bonnardel
- University of Grenoble-Alpes, CNRS, CERMAV, 38000 Grenoble, France;
- Swiss Institute of Bioinformatics, CH-1227 Geneva, Switzerland
- Computer Science Department, UniGe, CH-1227 Geneva, Switzerland
| | - Yu-Cheng Dai
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China; (A.L.); (Y.-C.D.)
| | - Anne Imberty
- University of Grenoble-Alpes, CNRS, CERMAV, 38000 Grenoble, France;
| | - Francis M. Martin
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China; (A.L.); (Y.-C.D.)
- Université de Lorraine, INRAE, UMR Interactions Arbres/Microorganismes (IAM), Laboratoire d’Excellence ARBRE, Centre INRAE GrandEst-Nancy, 54280 Champenoux, France
| | - Frédérique Lisacek
- Swiss Institute of Bioinformatics, CH-1227 Geneva, Switzerland
- Computer Science Department, UniGe, CH-1227 Geneva, Switzerland
- Section of Biology, UniGe, CH-1205 Geneva, Switzerland
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5
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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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6
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Abstract
The ecological modes of fungi are shaped not only by their intrinsic features and the environment in which they occur, but also by their interactions with diverse microbes. Here we explore the ecological and genomic features of diverse bacterial endosymbionts-endohyphal bacteria-that together are emerging as major determinants of fungal phenotypes and plant-fungi interactions. We first provide a historical perspective on the study of endohyphal bacteria. We then propose a functional classification of three main groups, providing an overview of their genomic, phylogenetic, and ecological traits. Last, we explore frontiers in the study of endohyphal bacteria, with special attention to those facultative and horizontally transmitted bacteria that associate with some of the most diverse lineages of fungi. Overall, our aim is to synthesize the rich literature from nearly 50 years of studies on endohyphal bacteria as a means to highlight potential applications and new research directions.
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Calcott MJ, Ackerley DF, Knight A, Keyzers RA, Owen JG. Secondary metabolism in the lichen symbiosis. Chem Soc Rev 2018; 47:1730-1760. [PMID: 29094129 DOI: 10.1039/c7cs00431a] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Lichens, which are defined by a core symbiosis between a mycobiont (fungal partner) and a photobiont (photoautotrophic partner), are in fact complex assemblages of microorganisms that constitute a largely untapped source of bioactive secondary metabolites. Historically, compounds isolated from lichens have predominantly been those produced by the dominant fungal partner, and these continue to be of great interest for their unique chemistry and biotechnological potential. In recent years it has become apparent that many photobionts and lichen-associated bacteria also produce a range of potentially valuable molecules. There is evidence to suggest that the unique nature of the symbiosis has played a substantial role in shaping many aspects of lichen chemistry, for example driving bacteria to produce metabolites that do not bring them direct benefit but are useful to the lichen as a whole. This is most evident in studies of cyanobacterial photobionts, which produce compounds that differ from free living cyanobacteria and are unique to symbiotic organisms. The roles that these and other lichen-derived molecules may play in communication and maintaining the symbiosis are poorly understood at present. Nonetheless, advances in genomics, mass spectrometry and other analytical technologies are continuing to illuminate the wealth of biological and chemical diversity present within the lichen holobiome. Implementation of novel biodiscovery strategies such as metagenomic screening, coupled with synthetic biology approaches to reconstitute, re-engineer and heterologously express lichen-derived biosynthetic gene clusters in a cultivable host, offer a promising means for tapping into this hitherto inaccessible wealth of natural products.
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Affiliation(s)
- Mark J Calcott
- School of Biological Sciences, Victoria University of Wellington, New Zealand.
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9
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Steinhäuser SS, Andrésson ÓS, Pálsson A, Werth S. Fungal and cyanobacterial gene expression in a lichen symbiosis: Effect of temperature and location. Fungal Biol 2016; 120:1194-208. [PMID: 27647237 DOI: 10.1016/j.funbio.2016.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 05/27/2016] [Accepted: 07/07/2016] [Indexed: 10/21/2022]
Abstract
Organisms have evolved different cellular mechanisms to deal with environmental stress, primarily through complex molecular mechanisms including protein refolding and DNA repair. As mutualistic symbioses, lichens offer the possibility of analyzing molecular stress responses in a particularly tight interspecific relationship. We study the widespread cyanolichen Peltigera membranacea, a key player in carbon and nitrogen cycling in terrestrial ecosystems at northern latitudes. We ask whether increased temperature is reflected in mRNA levels of selected damage control genes, and do the response patterns show geographical associations? Using real-time PCR quantification of 38 transcripts, differential expression was demonstrated for nine cyanobacterial and nine fungal stress response genes (plus the fungal symbiosis-related lec2 gene) when the temperature was increased from 5 °C to 15 °C and 25 °C. Principle component analysis (PCA) revealed two gene groups with different response patterns. Whereas a set of cyanobacterial DNA repair genes and the fungal lec2 (PC1 group) showed an expression drop at 15 °C vs. 5 °C, most fungal candidates (PC2 group) showed increased expression at 25 °C vs. 5 °C. PC1 responses also correlated with elevation. The correlated downregulation of lec2 and cyanobacterial DNA repair genes suggests a possible interplay between the symbionts warranting further studies.
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Affiliation(s)
- Sophie S Steinhäuser
- Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland
| | - Ólafur S Andrésson
- Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland
| | - Arnar Pálsson
- Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland
| | - Silke Werth
- Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland; Institute of Plant Sciences, University of Graz, Holteigasse 6, 8010 Graz, Austria.
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10
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Distribution patterns of haplotypes for symbionts from Umbilicaria esculenta and U. muehlenbergii reflect the importance of reproductive strategy in shaping population genetic structure. BMC Microbiol 2015; 15:212. [PMID: 26471277 PMCID: PMC4608304 DOI: 10.1186/s12866-015-0527-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 09/22/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The diversity of lichen fungal components and their photosynthetic partners reflects both ecological and evolutionary factors. In present study, molecular investigations of the internal transcribed spacer of the nuclear ribosomal DNA (ITS nrDNA) region were conducted to analyze the genetic diversity of Umbilicaria esculenta and U. muehlenbergii together with their associated green algae. RESULT It was here demonstrated that the reproductive strategy is a principal reason for fungal selectivity to algae. U. muehlenbergii, which disperses via sexual spores, exhibits lower selectivity to its photosynthetic partners than U. esculenta, which has a vegetative reproductive strategy. The difference of genotypic diversity (both fungal and algal) between these two Umbilicaria species is low, although their nucleotide diversity can vary greatly. CONCLUSIONS The present study illustrates that lichen-forming fungi with sexual reproductive strategies are less selective with respect to their photobionts; and reveals that both sexual and vegetative reproduction allow lichens to generate similar amounts of diversity to adapt to the environments. The current study will be helpful for elucidating how lichens with different reproductive strategies adapt to changing environments.
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Isolation and characterization of a novel lectin from the edible mushroom Stropharia rugosoannulata. Molecules 2014; 19:19880-91. [PMID: 25460311 PMCID: PMC6271533 DOI: 10.3390/molecules191219880] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/18/2014] [Accepted: 11/24/2014] [Indexed: 12/13/2022] Open
Abstract
To date, only a few steroids have been isolated from the mushroom Stropharia rugosoannulata which can be cultivated. In this paper, a novel lectin (SRL) with a molecular weight of 38 kDa, and a unique IKSGVYRIVSWQGALGPEAR N-terminal sequence was isolated from S. rugosoannulata, which represents the first protein isolated from the mushroom. The purification methods included (NH4)2SO4 precipitation, ion exchange chromatography on CM-cellulose, Q-Sepharose, and SP-Sepharose, and gel- filtration on Superdex-75. The lectin was adsorbed on all three types of ion exchangers and was purified more than 450-fold. The lectin was stable below 70 °C (with half of the activity preserved at 80 °C), and in the presence of NaOH and HCl solutions up to a concentration of 12.5 mM and 25 mM, respectively. The hemagglutinating activity of SRL was inhibited by inulin. Cd2+ and Hg2+ ions strongly reduced the hemagglutinating activity at concentrations from 1.25 mM to 10 mM. SRL exhibited anti-proliferative activity toward both hepatoma Hep G2 cells and leukemia L1210 cells, with an IC50 of 7 μM and 19 μM, respectively. The activity of HIV-1 reverse transcriptase could also be inhibited by SRL, with an IC50 of 10 μM.
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12
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Antimicrobial activity and carbohydrate specificity of new mycelial lectins from Fusarium sp. Biologia (Bratisl) 2014. [DOI: 10.2478/s11756-014-0449-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Magain N, Sérusiaux E. Do photobiont switch and cephalodia emancipation act as evolutionary drivers in the lichen symbiosis? A case study in the Pannariaceae (Peltigerales). PLoS One 2014; 9:e89876. [PMID: 24587091 PMCID: PMC3933699 DOI: 10.1371/journal.pone.0089876] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/27/2014] [Indexed: 11/23/2022] Open
Abstract
Lichen symbioses in the Pannariaceae associate an ascomycete and either cyanobacteria alone (usually Nostoc; bipartite thalli) or green algae and cyanobacteria (cyanobacteria being located in dedicated structures called cephalodia; tripartite thalli) as photosynthetic partners (photobionts). In bipartite thalli, cyanobacteria can either be restricted to a well-delimited layer within the thallus ('pannarioid' thalli) or spread over the thallus that becomes gelatinous when wet ('collematoid' thalli). We studied the collematoid genera Kroswia and Physma and an undescribed tripartite species along with representatives of the pannarioid genera Fuscopannaria, Pannaria and Parmeliella. Molecular inferences from 4 loci for the fungus and 1 locus for the photobiont and statistical analyses within a phylogenetic framework support the following: (a) several switches from pannarioid to collematoid thalli occured and are correlated with photobiont switches; the collematoid genus Kroswia is nested within the pannarioid genus Fuscopannaria and the collematoid genus Physma is sister to the pannarioid Parmeliella mariana group; (b) Nostoc associated with collematoid thalli in the Pannariaceae are related to that of the Collemataceae (which contains only collematoid thalli), and never associated with pannarioid thalli; Nostoc associated with pannarioid thalli also associate in other families with similar morphology; (c) ancestors of several lineages in the Pannariaceae developed tripartite thalli, bipartite thalli probably resulting from cephalodia emancipation from tripartite thalli which eventually evolved and diverged, as suggested by the same Nostoc present in the collematoid genus Physma and in the cephalodia of a closely related tripartite species; Photobiont switches and cephalodia emancipation followed by divergence are thus suspected to act as evolutionary drivers in the family Pannariaceae.
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Affiliation(s)
- Nicolas Magain
- Evolution and Conservation Biology Unit, University of Liège, Liège, Belgium
| | - Emmanuël Sérusiaux
- Evolution and Conservation Biology Unit, University of Liège, Liège, Belgium
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15
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Abstract
Fungi are members of a large group of eukaryotic organisms that include yeasts and molds, as well as the most familiar member, mushrooms. Fungal lectins with unique specificity and structures have been discovered. In general, fungal lectins are classified into specific families based on their amino acid sequences and three-dimensional structures. In this chapter, we provide an overview of the approximately 80 types of mushroom and fungal lectins that have been isolated and studied to date. In particular, we have focused on ten fungal lectins (Agaricus bisporus, Agrocybe cylindracea, Aleuria aurantia, Aspergillus oryzae, Clitocybe nebularis, Marasmius oreades, Psathyrella velutina, Rhizopus stolonifer, Pholiota squarrosa, Polyporus squamosus), many of which are commercially available and their properties, sugar-binding specificities, structural grouping into families, and applications for biological research being described. The sialic acid-specific lectins (Agrocybe cylindracea and Polyporus squamosus) and fucose-specific lectins (Aleuria aurantia, Aspergillus oryzae, Rhizopus stolonifer, and Pholiota squarrosa) each showed potential for use in identifying sialic acid glycoconjugates and fucose glycoconjugates. Although not much is currently known about fungal lectins compared to animal and plant lectins, the knowledge accumulated thus far shows great promise for several applications in the fields of taxonomy, biomedicine, and molecular and cellular biology.
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Affiliation(s)
- Yuka Kobayashi
- J-Oil Mills Inc., 11, Kagetoricho, Totsuka-ku, Yokohama, Kanagawa, 245-0064, Japan,
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de Vasconcelos TL, Pereira EC, da Silva NH, Vicente C, Legaz ME. Intracellular urease activity in the lichen Cladonia verticillaris, and its implication for toxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 98:310-316. [PMID: 24367816 DOI: 10.1016/j.ecoenv.2013.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Urea is currently used as a nitrogen fertilizer in many plant cultures, such as sugar cane. Several lichen species grow in the edges of the fields fertilized with urea. This implies that the hydrolysis of an excess of urea by soil bacteria or by the lichens themselves would increase the concentration of ammonia in the lichen thallus to a level that may be toxic to the photobiont. However, Cladonia verticillaris produces urease through positive feedback by urea supplied from the medium. This urease is partially secreted to the media or retained on the external surface of algal cells, as demonstrated herein by an adequate cytochemical reaction. This implies that ammonia produced by urea hydrolysis will be immediately dissolved in the water filling the intercellular spaces on the thallus. A possible protection mechanism against eventual ammonia toxicity, derived from the results described here, is also discussed.
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Fungal lectins: structure, function and potential applications. Curr Opin Struct Biol 2013; 23:678-85. [DOI: 10.1016/j.sbi.2013.07.007] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/18/2013] [Accepted: 07/11/2013] [Indexed: 11/20/2022]
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Manoharan SS, Miao VPW, Andrésson ÓS. LEC-2, a highly variable lectin in the lichen Peltigera membranacea.. Symbiosis 2012; 58:91-98. [PMID: 23482294 PMCID: PMC3589653 DOI: 10.1007/s13199-012-0206-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 11/26/2012] [Indexed: 12/31/2022]
Abstract
Lectins are a diverse group of carbohydrate binding proteins often involved in cellular interactions. A lectin gene, lec-2, was identified in the mycobiont of the lichen Peltigera membranacea. Sequencing of lec-2 open reading frames from 21 individual samples showed an unexpectedly high level of polymorphism in the deduced protein (LEC-2), which was sorted into nine haplotypes based on amino acid sequence. Calculations showed that the rates of nonsynonymous versus synonymous nucleotide substitutions deviated significantly from the null hypothesis of neutrality, indicating strong positive selection. Molecular modeling revealed that most amino acid replacements were around the putative carbohydrate-binding pocket, indicating changes in ligand binding. Lectins have been thought to be involved in the recognition of photobiont partners in lichen symbioses, and the hypothesis that positive selection of LEC-2 is driven by variation in the Nostoc photobiont partner was tested by comparing mycobiont LEC-2 haplotypes and photobiont genotypes, as represented by the rbcLX region. It was not possible to pair up the two types of marker sequences without conflicts, suggesting that positive selection of LEC-2 was not due to variation in photobiont partners.
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Affiliation(s)
- Sheeba S. Manoharan
- Department of Life and Environmental Sciences, University of Iceland, 101 Reykjavík, Iceland
| | - Vivian P. W. Miao
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Ólafur S. Andrésson
- Department of Life and Environmental Sciences, University of Iceland, 101 Reykjavík, Iceland
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