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Descourvières E, Petruzzellis F, Falace A, Nardini A, Tomasella M. Water relations and photosystem II efficiency of the intertidal macroalga Fucus virsoides. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 215:109000. [PMID: 39106766 DOI: 10.1016/j.plaphy.2024.109000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 07/11/2024] [Accepted: 07/30/2024] [Indexed: 08/09/2024]
Abstract
Intertidal macroalgae are sessile poikilohydric organisms exposed to desiccation stress during emersion. Water relations parameters are useful tools to evaluate an organism's capacity to withstand water scarcity conditions, but such information on marine intertidal macroalgae is scarce. We assessed the water relations of the intertidal relict Fucus virsoides, the unique Fucus species endemic to the Mediterranean. We combined measurements of water potential (Ψ) parameters derived from pressure-volume curves and chlorophyll a fluorescence (Fv/Fm) in juvenile and adult thalli sampled in three different dates between March and April 2023. F. virsoides exhibited remarkable water stress tolerance, as evidenced by the low water potential at turgor loss point (Ψtlp, -7.0 MPa on average), and the maintenance of high Fv/Fm at low water potentials indicating a prolonged maintenance of healthy physiological status. While no differences were observed between growth stages, Ψtlp, capacitance (C) and the bulk modulus of elasticity (ε) varied significantly according to the sampling dates, whereas the osmotic potential at full turgor did not significantly change. Ψ measured on thalli collected after a typical prolonged emersion period was markedly lower (-12.3 MPa on average) than the estimated Ψtlp, suggesting that the population is frequently undergoing turgor loss. Further investigations are required to determine environmental tolerance ranges based on water status characteristics to enhance our understanding of F. virsoides responses and vulnerability to climate change, thus providing insight into the possible causes of its widespread decline.
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Affiliation(s)
- Emmanuelle Descourvières
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; National Institute of Oceanography and Applied Geophysics - OGS, Via Beirut 2, 34014 Trieste, Italy
| | - Francesco Petruzzellis
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Annalisa Falace
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Martina Tomasella
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy.
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Leksin I, Shelyakin M, Zakhozhiy I, Kozlova O, Beckett R, Minibayeva F. Ultraviolet-induced melanisation in lichens: physiological traits and transcriptome profile. PHYSIOLOGIA PLANTARUM 2024; 176:e14512. [PMID: 39221518 DOI: 10.1111/ppl.14512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 08/14/2024] [Accepted: 08/20/2024] [Indexed: 09/04/2024]
Abstract
Lichens are important components of high-latitude boreal and Arctic habitats. While stress tolerant, they are among the most sensitive ecosystem components to climate change, in particular, an increase in ultraviolet light (UV) arising from polar ozone depletion and deforestation. This study is the first to explore the effects of UV-B on gene expression in lichens to predict metabolic pathways involved in tolerance. Using transcriptome profiling and bioinformatic analyses, here we studied the effects of UV-B on gene expression in lichens using Lobaria pulmonaria (L.) Hoff. as a model species. UV-B exposure causes significant browning of the upper cortex of the thallus, which correlates to an increased expression of biosynthetic gene clusters involved in the synthesis of eu- and allomelanins and melanin precursors. Based on transcriptome analyses, we suggest that the biosynthesis of melanins and other secondary metabolites, such as naphthalene derivates, tropolones, anthraquinones, and xanthones, is a trade-off that lichens pay to protect essential metabolic processes such as photosynthesis and respiration. Expression profiles of general stress-associated genes, in particular, related to reactive oxygen species scavenging, protection of proteins, and DNA repair, clearly indicate that the mycobiont is the more UV-B-responsive and susceptible partner in lichen symbiosis. Our findings demonstrate that UV-B stress activates an intricate gene network involved in tolerance mechanisms of lichen symbionts. Knowledge obtained here may enable the prediction of likely effects on lichen biodiversity caused by climate change and pollution.
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Affiliation(s)
- Ilya Leksin
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russian Federation
| | - Mikhail Shelyakin
- Institute of Biology of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences
| | - Ilya Zakhozhiy
- Institute of Biology of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences
| | - Olga Kozlova
- Kazan (Volga Region) Federal University, Kazan, Russian Federation
| | - Richard Beckett
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russian Federation
- University of KwaZulu-Natal, Scottsville, South Africa
| | - Farida Minibayeva
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russian Federation
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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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Acquisition of desiccation tolerance in Haematococcus pluvialis requires photosynthesis and coincides with lipid and astaxanthin accumulation. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102699] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Terlova EF, Holzinger A, Lewis LA. Terrestrial Green Algae Show Higher Tolerance to Dehydration than Do Their Aquatic Sister-Species. MICROBIAL ECOLOGY 2021; 82:770-782. [PMID: 33502573 PMCID: PMC7612456 DOI: 10.1007/s00248-020-01679-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 12/29/2020] [Indexed: 05/09/2023]
Abstract
Diverse algae possess the ability to recover from extreme desiccation without forming specialized resting structures. Green algal genera such as Tetradesmus (Sphaeropleales, Chlorophyceae) contain temperate terrestrial, desert, and aquatic species, providing an opportunity to compare physiological traits associated with the transition to land in closely related taxa. We subjected six species from distinct habitats to three dehydration treatments varying in relative humidity (RH 5%, 65%, 80%) followed by short- and long-term rehydration. We tested the capacity of the algae to recover from dehydration using the effective quantum yield of photosystem II as a proxy for physiological activity. The degree of recovery was dependent both on the habitat of origin and the dehydration scenario, with terrestrial, but not aquatic, species recovering from dehydration. Distinct strains of each species responded similarly to dehydration and rehydration, with the exception of one aquatic strain that recovered from the mildest dehydration treatment. Cell ultrastructure was uniformly maintained in both aquatic and desert species during dehydration and rehydration, but staining with an amphiphilic styryl dye indicated damage to the plasma membrane from osmotically induced water loss in the aquatic species. These analyses demonstrate that terrestrial Tetradesmus possess a vegetative desiccation tolerance phenotype, making these species ideal for comparative omics studies.
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Affiliation(s)
- Elizaveta F Terlova
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA.
| | - Andreas Holzinger
- Department of Botany, Functional Plant Biology, University of Innsbruck, Innsbruck, Austria
| | - Louise A Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA
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Gasulla F, del Campo EM, Casano LM, Guéra A. Advances in Understanding of Desiccation Tolerance of Lichens and Lichen-Forming Algae. PLANTS (BASEL, SWITZERLAND) 2021; 10:807. [PMID: 33923980 PMCID: PMC8073698 DOI: 10.3390/plants10040807] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 12/11/2022]
Abstract
Lichens are symbiotic associations (holobionts) established between fungi (mycobionts) and certain groups of cyanobacteria or unicellular green algae (photobionts). This symbiotic association has been essential in the colonization of terrestrial dry habitats. Lichens possess key mechanisms involved in desiccation tolerance (DT) that are constitutively present such as high amounts of polyols, LEA proteins, HSPs, a powerful antioxidant system, thylakoidal oligogalactolipids, etc. This strategy allows them to be always ready to survive drastic changes in their water content. However, several studies indicate that at least some protective mechanisms require a minimal time to be induced, such as the induction of the antioxidant system, the activation of non-photochemical quenching including the de-epoxidation of violaxanthin to zeaxanthin, lipid membrane remodeling, changes in the proportions of polyols, ultrastructural changes, marked polysaccharide remodeling of the cell wall, etc. Although DT in lichens is achieved mainly through constitutive mechanisms, the induction of protection mechanisms might allow them to face desiccation stress in a better condition. The proportion and relevance of constitutive and inducible DT mechanisms seem to be related to the ecology at which lichens are adapted to.
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Affiliation(s)
- Francisco Gasulla
- Department of Life Sciences, Universidad de Alcalá, Alcalá de Henares, 28802 Madrid, Spain; (E.M.d.C.); (L.M.C.)
| | | | | | - Alfredo Guéra
- Department of Life Sciences, Universidad de Alcalá, Alcalá de Henares, 28802 Madrid, Spain; (E.M.d.C.); (L.M.C.)
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Farrant JM, Hilhorst HWM. What is dry? Exploring metabolism and molecular mobility at extremely low water contents. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:1507-1510. [PMID: 33649767 PMCID: PMC7921294 DOI: 10.1093/jxb/eraa579] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This article comments on: Candotto Carniel FC, Fernandez-Marín B, Arc E, Craighero T, Laza MJ, Incerti G, Tretiach M, Kranner I. 2021. How dry is dry? Molecular mobility in relation to thallus water content in a lichen. Journal of Experimental Botany 72, 1576–1588
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Affiliation(s)
- Jill M Farrant
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Henk W M Hilhorst
- Laboratory of Plant Physiology, Wageningen University and Research, Wageningen, The Netherlands
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Candotto Carniel F, Fernandez-Marín B, Arc E, Craighero T, Laza JM, Incerti G, Tretiach M, Kranner I. How dry is dry? Molecular mobility in relation to thallus water content in a lichen. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:1576-1588. [PMID: 33165603 DOI: 10.1093/jxb/eraa521] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 10/30/2020] [Indexed: 05/28/2023]
Abstract
Lichens can withstand extreme desiccation to water contents of ≤ 0.1 g H2O g-1 DW, and in the desiccated state are among the most extremotolerant organisms known. Desiccation-tolerant life-forms such as seeds, mosses and lichens survive 'vitrification', that is the transition of their cytoplasm to a 'glassy' state, which causes metabolism to cease. However, our understanding of the mechanisms of desiccation tolerance is hindered by poor knowledge of what reactions occur in the desiccated state. Using Flavoparmelia caperata as a model lichen, we determined at what water contents vitrification occurred upon desiccation. Molecular mobility was assessed by dynamic mechanical thermal analysis, and the de- and re-epoxidation of the xanthophyll cycle pigments (measured by HPLC) was used as a proxy to assess enzyme activity. At 20 °C vitrification occurred between 0.12-0.08 g H2O g-1 DW and enzymes were active in a 'rubbery' state (0.17 g H2O g-1 DW) but not in a glassy state (0.03 g H2O g-1 DW). Therefore, desiccated tissues may appear to be 'dry' in the conventional sense, but subtle differences in water content will have substantial consequences on the types of (bio)chemical reactions that can occur, with downstream effects on longevity in the desiccated state.
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Affiliation(s)
- Fabio Candotto Carniel
- Department of Botany, University of Innsbruck, Innsbruck, Austria
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Beatriz Fernandez-Marín
- Department of Botany, University of Innsbruck, Innsbruck, Austria
- Department of Botany, Ecology and Plant Physiology, University of La Laguna (ULL), Tenerife, Spain
| | - Erwann Arc
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Teresa Craighero
- Department of Botany, University of Innsbruck, Innsbruck, Austria
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - José Manuel Laza
- Department of Physical Chemistry, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Guido Incerti
- Department of Agri-Food, Animal and Environmental Sciences (DI4A), University of Udine, Udine, Italy
| | - Mauro Tretiach
- Department of Botany, Ecology and Plant Physiology, University of La Laguna (ULL), Tenerife, Spain
| | - Ilse Kranner
- Department of Botany, University of Innsbruck, Innsbruck, Austria
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Aigner S, Glaser K, Arc E, Holzinger A, Schletter M, Karsten U, Kranner I. Adaptation to Aquatic and Terrestrial Environments in Chlorella vulgaris (Chlorophyta). Front Microbiol 2020; 11:585836. [PMID: 33178169 PMCID: PMC7593248 DOI: 10.3389/fmicb.2020.585836] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/14/2020] [Indexed: 11/20/2022] Open
Abstract
The globally distributed green microalga Chlorella vulgaris (Chlorophyta) colonizes aquatic and terrestrial habitats, but the molecular mechanisms underpinning survival in these two contrasting environments are far from understood. Here, we compared the authentic strain of C. vulgaris from an aquatic habitat with a strain from a terrestrial high alpine habitat previously determined as Chlorella mirabilis. Molecular phylogeny of SSU rDNA (823 bp) showed that the two strains differed by one nucleotide only. Sequencing of the ITS2 region confirmed that both strains belong to the same species, but to distinct ribotypes. Therefore, the terrestrial strain was re-assessed as C. vulgaris. To study the response to environmental conditions experienced on land, we assessed the effects of irradiance and temperature on growth, of temperature on photosynthesis and respiration, and of desiccation and rehydration on photosynthetic performance. In contrast to the aquatic strain, the terrestrial strain tolerated higher temperatures and light conditions, had a higher photosynthesis-to-respiration ratio at 25°C, still grew at 30°C and was able to fully recover photosynthetic performance after desiccation at 84% relative humidity. The two strains differed most in their response to the dehydration/rehydration treatment, which was further investigated by untargeted GC–MS-based metabolite profiling to gain insights into metabolic traits differentiating the two strains. The two strains differed in their allocation of carbon and nitrogen into their primary metabolites. Overall, the terrestrial strain had higher contents of readily available nitrogen-based metabolites, especially amino acids and the polyamine putrescine. Dehydration and rehydration led to differential regulation of the amino acid metabolism, the tricarboxylic acid cycle and sucrose metabolism. The data are discussed with a view to differences in phenotypic plasticity of the two strains, and we suggest that the two genetically almost identical C. vulgaris strains are attractive models to study mechanisms that protect from abiotic stress factors, which are more frequent in terrestrial than aquatic habitats, such as desiccation and irradiation.
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Affiliation(s)
- Siegfried Aigner
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Karin Glaser
- Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Erwann Arc
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | | | | | - Ulf Karsten
- Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Ilse Kranner
- Department of Botany, University of Innsbruck, 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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Jiang C, Bi Y, Zhang R, Feng S. Expression of RcHSP70, heat shock protein 70 gene from Chinese rose, enhances host resistance to abiotic stresses. Sci Rep 2020; 10:2445. [PMID: 32051436 PMCID: PMC7015905 DOI: 10.1038/s41598-020-58745-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 10/27/2019] [Indexed: 11/17/2022] Open
Abstract
There exist differences in the heat tolerance of Chinese rose varieties, and high temperature in summer can lead to failure of blooming in non-heat-tolerant Chinese rose varieties. We cloned a heat shock protein 70 gene (designated RcHSP70) from heat-tolerant varieties of Chinese rose (Rosa hybrida L.) to elucidate the molecular mechanism of heat tolerance and improve the quality of Chinese rose. Degenerate primers were designed for RcHSP70 according to the 5'- and 3'-end sequences of HSP70 genes in apple and tea. RcHSP70 was cloned from heat-tolerant Chinese rose varieties after heat shock. The heat shock-induced expression patterns of RcHSP70 in different Chinese rose varieties were analyzed by RT-PCR. Following heat shock (38 °C/3 h), RcHSP70 was highly expressed in the heat-tolerant varieties but not in the non-heat-tolerant varieties, indicating a close relationship between RcHSP70 and heat resistance in Chinese rose. To verify the function of RcHSP70, we constructed a prokaryotic expression recombinant vector for this gene and transformed it into Escherichia coli BL21. The tolerance of recombinant strains to abiotic stresses, including high temperature, low temperature, high salt, heavy metals, high pH, and oxidation, was evaluated. Additionally, RcHSP70 was transformed into tobacco plants. Because of the overexpression of this gene, transgenic tobacco plants improved their tolerance to high temperature and cold. In addition, transgenic tobacco showed better photosynthetic performance, relative electrical conductivity and proline content than wild tobacco after heat stress and cold stress. Our findings indicate that RcHSP70 is involved in the resistance of Chinese rose to abiotic stresses.
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Affiliation(s)
| | - Yuke Bi
- Shanghai Botanical Garden, Shanghai, China
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12
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Fernández-Marín B, López-Pozo M, Perera-Castro AV, Arzac MI, Sáenz-Ceniceros A, Colesie C, de los Ríos A, Sancho LG, Pintado A, Laza JM, Pérez-Ortega S, García-Plazaola JI. Symbiosis at its limits: ecophysiological consequences of lichenization in the genus Prasiola in Antarctica. ANNALS OF BOTANY 2020; 124:1211-1226. [PMID: 31549137 PMCID: PMC6943718 DOI: 10.1093/aob/mcz149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 09/13/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Lichens represent a symbiotic relationship between at least one fungal and one photosynthetic partner. The association between the lichen-forming fungus Mastodia tessellata (Verrucariaceae) and different species of Prasiola (Trebouxiophyceae) has an amphipolar distribution and represents a unique case study for the understanding of lichen symbiosis because of the macroalgal nature of the photobiont, the flexibility of the symbiotic interaction and the co-existence of free-living and lichenized forms in the same microenvironment. In this context, we aimed to (1) characterize the photosynthetic performance of co-occurring populations of free-living and lichenized Prasiola and (2) assess the effect of the symbiosis on water relations in Prasiola, including its tolerance of desiccation and its survival and performance under sub-zero temperatures. METHODS Photochemical responses to irradiance, desiccation and freezing temperature and pressure-volume curves of co-existing free-living and lichenized Prasiola thalli were measured in situ in Livingston Island (Maritime Antarctica). Analyses of photosynthetic pigment, glass transition and ice nucleation temperatures, surface hydrophobicity extent and molecular analyses were conducted in the laboratory. KEY RESULTS Free-living and lichenized forms of Prasiola were identified as two different species: P. crispa and Prasiola sp., respectively. While lichenization appears to have no effect on the photochemical performance of the alga or its tolerance of desiccation (in the short term), the symbiotic lifestyle involves (1) changes in water relations, (2) a considerable decrease in the net carbon balance and (3) enhanced freezing tolerance. CONCLUSIONS Our results support improved tolerance of sub-zero temperature as the main benefit of lichenization for the photobiont, but highlight that lichenization represents a delicate equilibrium between a mutualistic and a less reciprocal relationship. In a warmer climate scenario, the spread of the free-living Prasiola to the detriment of the lichen form would be likely, with unknown consequences for Maritime Antarctic ecosystems.
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Affiliation(s)
- Beatriz Fernández-Marín
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain
- Department of Botany, Ecology and Physiology, University of La Laguna (ULL), La Laguna, Canarias, Spain
| | - Marina López-Pozo
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Alicia V Perera-Castro
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB) - Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Palma, Illes Balears, Spain
| | - Miren Irati Arzac
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Ana Sáenz-Ceniceros
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Claudia Colesie
- Global Change Institute, School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | | | - Leo G Sancho
- Botany Section, Fac. Farmacia, Universidad Complutense, Madrid, Spain
| | - Ana Pintado
- Botany Section, Fac. Farmacia, Universidad Complutense, Madrid, Spain
| | - José M Laza
- Laboratory of Macromolecular Chemistry (Labquimac), Department of Physical Chemistry, University of the Basque Country (UPV/EHU), Leioa, Spain
| | | | - José I García-Plazaola
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain
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13
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Rippin M, Borchhardt N, Karsten U, Becker B. Cold Acclimation Improves the Desiccation Stress Resilience of Polar Strains of Klebsormidium (Streptophyta). Front Microbiol 2019; 10:1730. [PMID: 31447802 PMCID: PMC6691101 DOI: 10.3389/fmicb.2019.01730] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/12/2019] [Indexed: 11/13/2022] Open
Abstract
Biological soil crusts (BSCs) are complex communities of autotrophic, heterotrophic, and saprotrophic (micro)organisms. In the polar regions, these biocrust communities have essential ecological functions such as primary production, nitrogen fixation, and ecosystem engineering while coping with extreme environmental conditions (temperature, desiccation, and irradiation). The microalga Klebsormidium is commonly found in BSCs all across the globe. The ecophysiological resilience of various Klebsormidium species to desiccation and other stresses has been studied intensively. Here we present the results of transcriptomic analyses of two different Klebsormidium species, K. dissectum and K. flaccidum, isolated from Antarctic and Arctic BSCs. We performed desiccation stress experiments at two different temperatures mimicking fluctuations associated with global change. Cultures grown on agar plates were desiccated on membrane filters at 10% relative air humidity until the photosynthetic activity as reflected in the effective quantum yield of photosystem II [Y(II)] ceased. For both species, the response to dehydration was much faster at the higher temperature. At the transcriptome level both species responded more strongly to the desiccation stress at the higher temperature suggesting that adaptation to cold conditions enhanced the resilience of both algae to desiccation stress. Interestingly, the two different species responded differently to the applied desiccation stress with respect to the number as well as function of genes showing differential gene expression. The portion of differentially expressed genes shared between both taxa was surprisingly low indicating that both Klebsormidium species adapted independently to the harsh conditions of Antarctica and the Arctic, respectively. Overall, our results indicate that environmental acclimation has a great impact on gene expression and the response to desiccation stress in Klebsormidium.
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Affiliation(s)
- Martin Rippin
- Department of Biology, Botanical Institute, University of Cologne, Cologne, Germany
| | | | - Ulf Karsten
- Department of Biology, University of Rostock, Rostock, Germany
| | - Burkhard Becker
- Department of Biology, Botanical Institute, University of Cologne, Cologne, Germany
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14
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Bianchi E, Benesperi R, Colzi I, Coppi A, Lazzaro L, Paoli L, Papini A, Pignattelli S, Tani C, Vignolini P, Gonnelli C. The multi-purpose role of hairiness in the lichens of coastal environments: Insights from Seirophora villosa (Ach.) Frödén. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 141:398-406. [PMID: 31228796 DOI: 10.1016/j.plaphy.2019.06.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/14/2019] [Accepted: 06/15/2019] [Indexed: 06/09/2023]
Abstract
The fruticose epiphytic lichen Seirophora villosa, strictly associated with Juniperus shrublands in the Mediterranean basin, was used to investigate the role of hairiness on a lichen thallus, as a characteristic morphological trait. We evaluated the effect of hair removal on the physiological parameters of a set of samples, during desiccation and on exposure to different salt concentrations. Hairy thalli were less affected by salt, suggesting that during dehydration, the presence of hair protects the thallus from light irradiance, oxidative stresses and the lipid peroxidation generated by free radicals, and could offer passive, but selective, water control. Our results showed that hair could not only increase thallus surface and promote water absorption when availability is low, but could also repel the salt dissolved in water by activating a passive resistance mechanism, by preventing salt entering.
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Affiliation(s)
- Elisabetta Bianchi
- Department of Biology, University of Florence, via G. La Pira 4, I-50121, Florence, Italy
| | - Renato Benesperi
- Department of Biology, University of Florence, via G. La Pira 4, I-50121, Florence, Italy
| | - Ilaria Colzi
- Department of Biology, University of Florence, via Micheli 1, I-50121, Florence, Italy.
| | - Andrea Coppi
- Department of Biology, University of Florence, via Micheli 1, I-50121, Florence, Italy
| | - Lorenzo Lazzaro
- Department of Biology, University of Florence, via G. La Pira 4, I-50121, Florence, Italy
| | - Luca Paoli
- Department of Biology, University of Pisa, via L. Ghini 13, I-56126, Pisa, Italy
| | - Alessio Papini
- Department of Biology, University of Florence, via Micheli 3, I-50121, Florence, Italy
| | - Sara Pignattelli
- Department of Biology, University of Florence, via Micheli 1, I-50121, Florence, Italy
| | - Corrado Tani
- Department of Biology, University of Florence, via Micheli 3, I-50121, Florence, Italy
| | - Pamela Vignolini
- Phytolab - Department of Statistics, Informatics, Applications, University of Florence, Via U. Schiff 6, I-50019, Sesto Fiorentino, FI, Italy
| | - Cristina Gonnelli
- Department of Biology, University of Florence, via Micheli 1, I-50121, Florence, Italy
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15
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Hell AF, Gasulla F, Gonzï Lez-Hourcade MA, Del Campo EM, Centeno DC, Casano LM. Tolerance to Cyclic Desiccation in Lichen Microalgae is Related to Habitat Preference and Involves Specific Priming of the Antioxidant System. PLANT & CELL PHYSIOLOGY 2019; 60:1880-1891. [PMID: 31127294 DOI: 10.1093/pcp/pcz103] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/15/2019] [Indexed: 06/09/2023]
Abstract
Oxidative stress is a crucial challenge for lichens exposed to cyclic desiccation and rehydration (D/R). However, strategies to overcome this potential stress are still being unraveled. Therefore, the physiological performance and antioxidant mechanisms of two lichen microalgae, Trebouxia sp. (TR9) and Coccomyxa simplex (Csol), were analyzed. TR9 was isolated from Ramalina farinacea, a Mediterranean fruticose epiphytic lichen adapted to xeric habitats, while Csol is the phycobiont of Solorina saccata, a foliaceous lichen that grows on humid rock crevices. The tolerance to desiccation of both species was tested by subjecting them to different drying conditions and to four consecutive daily cycles of D/R. Our results show that a relative humidity close to that of their habitats was crucial to maintain the photosynthetic rates. Concerning antioxidant enzymes, in general, manganese superoxide dismutases (MnSODs) were induced after desiccation and decreased after rehydration. In TR9, catalase (CAT)-A increased, and its activity was maintained after four cycles of D/R. Ascorbate peroxidase activity was detected only in Csol, while glutathione reductase increased only in TR9. Transcript levels of antioxidant enzymes indicate that most isoforms of MnSOD and FeSOD were induced by desiccation and repressed after rehydration. CAT2 gene expression was also upregulated and maintained at higher levels even after four cycles of D/R in accordance with enzymatic activities. To our knowledge, this is the first study to include the complete set of the main antioxidant enzymes in desiccation-tolerant microalgae. The results highlight the species-specific induction of the antioxidant system during cyclic D/R, suggesting a priming of oxidative defence metabolism.
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Affiliation(s)
- Aline F Hell
- Department of Life Sciences, University of Alcal�, Alcal� de Henares, Madrid, Spain
- Centre of Natural Sciences and Humanities, Federal University of ABC, S�o Bernardo do Campo, SP, Brazil
| | - Francisco Gasulla
- Department of Life Sciences, University of Alcal�, Alcal� de Henares, Madrid, Spain
| | | | - Eva M Del Campo
- Department of Life Sciences, University of Alcal�, Alcal� de Henares, Madrid, Spain
| | - Danilo C Centeno
- Centre of Natural Sciences and Humanities, Federal University of ABC, S�o Bernardo do Campo, SP, Brazil
| | - Leonardo M Casano
- Department of Life Sciences, University of Alcal�, Alcal� de Henares, Madrid, Spain
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16
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Banchi E, Candotto Carniel F, Montagner A, Bosi S, Bramini M, Crosera M, León V, Martín C, Pallavicini A, Vázquez E, Prato M, Tretiach M. Graphene-based materials do not impair physiology, gene expression and growth dynamics of the aeroterrestrial microalga Trebouxia gelatinosa. Nanotoxicology 2019; 13:492-509. [PMID: 31241384 DOI: 10.1080/17435390.2019.1570371] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The effects of two graphene-based materials (GBMs), few-layers graphene (FLG) and graphene oxide (GO), were studied in the aeroterrestrial green microalga Trebouxia gelatinosa. Algae were subjected to short- and long-term exposure to GBMs at 0.01, 1 and 50 μg mL - 1. GBMs internalization after short-term exposures was investigated with confocal microscopy, Raman spectroscopy and TEM. Potential negative effects of GBMs, compared to the oxidative stress induced by H2O2, were verified by analyzing chlorophyl a fluorescence (ChlaF), expression of stress-related genes and membrane integrity. Effects of up to 4-week-long exposures were assessed analyzing growth dynamics, ChlaF and photosynthetic pigments. GBMs were not observed in cells but FLG was detected at the interface between the cell wall and plasma membrane, whereas GO was observed adherent to the external wall surface. FLG caused the down-regulation of the HSP70-1 gene, with the protein levels remaining stable, whereas GO had no effect. In comparison, H2O2 produced dose- and time-dependent effects on ChlaF, gene expression and HSP70 protein level. Long-term exposures to GBMs did not affect growth dynamics, ChlaF or photosynthetic pigment contents, indicating that the few observed short-term effects were not dangerous on the long-term. Results suggest that interactions between FLG and plasma membrane were harmless, activating a down-regulation of the HSP70-1 gene similar to that induced by H2O2. Our work shows that studying GBMs effects on non-model organisms is important since the results of model green microalgae are not representative of the whole taxonomic group.
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Affiliation(s)
- Elisa Banchi
- a Department of Life Sciences , University of Trieste , Trieste , Italy
| | | | - Alice Montagner
- a Department of Life Sciences , University of Trieste , Trieste , Italy
| | - Susanna Bosi
- b Department of Chemical and Pharmaceutical Sciences , University of Trieste , Trieste , Italy
| | - Mattia Bramini
- c Center for Synaptic Neuroscience and Technology , Italian Institute of Technology , Genova , Italy
| | - Matteo Crosera
- b Department of Chemical and Pharmaceutical Sciences , University of Trieste , Trieste , Italy
| | - Verónica León
- d Department of Organic Chemistry , Faculty of Chemical Science and Technology, University of Castilla-La Mancha , Ciudad Real , Spain.,e Regional Institute of Applied Scientific Investigation (IRICA) , University of Castilla-La Mancha , Ciudad Real , Spain
| | - Cristina Martín
- d Department of Organic Chemistry , Faculty of Chemical Science and Technology, University of Castilla-La Mancha , Ciudad Real , Spain.,e Regional Institute of Applied Scientific Investigation (IRICA) , University of Castilla-La Mancha , Ciudad Real , Spain
| | | | - Ester Vázquez
- d Department of Organic Chemistry , Faculty of Chemical Science and Technology, University of Castilla-La Mancha , Ciudad Real , Spain.,e Regional Institute of Applied Scientific Investigation (IRICA) , University of Castilla-La Mancha , Ciudad Real , Spain
| | - Maurizio Prato
- b Department of Chemical and Pharmaceutical Sciences , University of Trieste , Trieste , Italy.,f Carbon Nanobiotechnology Laboratory , CIC biomaGUNE , San Sebastian , Spain
| | - Mauro Tretiach
- a Department of Life Sciences , University of Trieste , Trieste , Italy
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