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Robinson SA, Revell LE, Mackenzie R, Ossola R. Extended ozone depletion and reduced snow and ice cover-Consequences for Antarctic biota. GLOBAL CHANGE BIOLOGY 2024; 30:e17283. [PMID: 38663017 DOI: 10.1111/gcb.17283] [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: 01/02/2024] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 05/25/2024]
Abstract
Stratospheric ozone, which has been depleted in recent decades by the release of anthropogenic gases, is critical for shielding the biosphere against ultraviolet-B (UV-B) radiation. Although the ozone layer is expected to recover before the end of the 21st century, a hole over Antarctica continues to appear each year. Ozone depletion usually peaks between September and October, when fortunately, most Antarctic terrestrial vegetation and soil biota is frozen, dormant and protected under snow cover. Similarly, much marine life is protected by sea ice cover. The ozone hole used to close before the onset of Antarctic summer, meaning that most biota were not exposed to severe springtime UV-B fluxes. However, in recent years, ozone depletion has persisted into December, which marks the beginning of austral summer. Early summertime ozone depletion is concerning: high incident UV-B radiation coincident with snowmelt and emergence of vegetation will mean biota is more exposed. The start of summer is also peak breeding season for many animals, thus extreme UV-B exposure (UV index up to 14) may come at a vulnerable time in their life cycle. Climate change, including changing wind patterns and strength, and particularly declining sea ice, are likely to compound UV-B exposure of Antarctic organisms, through earlier ice and snowmelt, heatwaves and droughts. Antarctic field research conducted decades ago tended to study UV impacts in isolation and more research that considers multiple climate impacts, and the true magnitude and timing of current UV increases is needed.
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Affiliation(s)
- Sharon A Robinson
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, New South Wales, Australia
- Environmental Futures, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Laura E Revell
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| | - Roy Mackenzie
- Cape Horn International Center CHIC, Universidad de Magallanes, Puerto Williams, Chile
- Millenium Institut Biodiversity of Antarctic and Subantarctic Ecosystems BASE, Santiago, Chile
| | - Rachele Ossola
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, USA
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Yin H, Perera-Castro AV, Randall KL, Turnbull JD, Waterman MJ, Dunn J, Robinson SA. Basking in the sun: how mosses photosynthesise and survive in Antarctica. PHOTOSYNTHESIS RESEARCH 2023; 158:151-169. [PMID: 37515652 PMCID: PMC10684656 DOI: 10.1007/s11120-023-01040-y] [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: 02/15/2023] [Accepted: 07/10/2023] [Indexed: 07/31/2023]
Abstract
The Antarctic environment is extremely cold, windy and dry. Ozone depletion has resulted in increasing ultraviolet-B radiation, and increasing greenhouse gases and decreasing stratospheric ozone have altered Antarctica's climate. How do mosses thrive photosynthetically in this harsh environment? Antarctic mosses take advantage of microclimates where the combination of protection from wind, sufficient melt water, nutrients from seabirds and optimal sunlight provides both photosynthetic energy and sufficient warmth for efficient metabolism. The amount of sunlight presents a challenge: more light creates warmer canopies which are optimal for photosynthetic enzymes but can contain excess light energy that could damage the photochemical apparatus. Antarctic mosses thus exhibit strong photoprotective potential in the form of xanthophyll cycle pigments. Conversion to zeaxanthin is high when conditions are most extreme, especially when water content is low. Antarctic mosses also produce UV screening compounds which are maintained in cell walls in some species and appear to protect from DNA damage under elevated UV-B radiation. These plants thus survive in one of the harshest places on Earth by taking advantage of the best real estate to optimise their metabolism. But survival is precarious and it remains to be seen if these strategies will still work as the Antarctic climate changes.
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Affiliation(s)
- Hao Yin
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | | | - Krystal L Randall
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Johanna D Turnbull
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Melinda J Waterman
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Jodie Dunn
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Sharon A Robinson
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia.
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Martínez-Abaigar J, Núñez-Olivera E. Bryophyte ultraviolet-omics: from genes to the environment. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4412-4426. [PMID: 35274697 DOI: 10.1093/jxb/erac090] [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: 01/02/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
Ultraviolet (UV) radiation has contributed to the evolution of organisms since the origins of life. Bryophytes also have evolutionary importance as the first clearly identified lineage of land plants (embryophytes) colonizing the terrestrial environment, thus facing high UV and water scarcity, among other new challenges. Here we review bryophyte UV-omics, the discipline relating bryophytes and UV, with an integrative perspective from genes to the environment. We consider species and habitats investigated, methodology, response variables, protection mechanisms, environmental interactions, UV biomonitoring, molecular and evolutionary aspects, and applications. Bryophyte UV-omics shows convergences and divergences with the UV-omics of other photosynthetic organisms, from algae to tracheophytes. All these organisms converge in that UV damage may be limited under realistic UV levels, due to structural protection and/or physiological acclimation capacity. Nevertheless, bryophytes diverge because they have a unique combination of vegetative and reproductive characteristics to cope with high UV and other concomitant adverse processes, such as desiccation. This interaction has both evolutionary and ecological implications. In addition, UV effects on bryophytes depend on the species and the evolutionary lineage considered, with mosses more UV-tolerant than liverworts. Thus, bryophytes do not constitute a homogeneous functional type with respect to their UV tolerance.
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Affiliation(s)
- Javier Martínez-Abaigar
- Faculty of Science and Technology, University of La Rioja, Madre de Dios 53, 26006 Logroño, Spain
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Ruklani S, Rubasinghe SCK, Jayasuriya G. A review of frameworks for using bryophytes as indicators of climate change with special emphasis on Sri Lankan bryoflora. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:60425-60437. [PMID: 34537948 DOI: 10.1007/s11356-021-16588-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
The tropical island of Sri Lanka, with a land area of 65,610 km2 and 1340 km of coastline, is highly vulnerable to impacts of climate change, with detrimental effects on agriculture, water resources, human health, coastal zones, infrastructure, industry, and biodiversity. A general increase in temperature and precipitation patterns, rising sea levels, and increase in weather-related natural disasters, such as floods and droughts, have been traced over the years. Bryophytes (liverworts, mosses, hornworts) occupy a pivotal position in the land plant evolution and form a unique part of the vegetation. Many taxa of bryophytes exhibit observable, distinct adaptations in response to changes in environmental conditions quickly. Bryophytes can be used to monitor climate change in two ways; (i) presence or absence in the ecosystem and (ii) changes in morphology and physiology that can be used for monitoring. Sri Lanka has a rich bryophyte flora consisting of 575 species of mosses, 338 species of liverworts, and 07 species of hornworts. It is estimated that 11% of mosses are endemic; there are no endemic thalloid liverworts or hornworts found in Sri Lanka, and the endemicity of leafy liverworts is yet to be investigated. The taxonomic status of endemic taxa and the biogeographic affinities of many taxa remain unexplored. Further, the potential use of bryophytes as indicators of climate change in Sri Lanka has not yet been investigated. This paper compiles the information on morphological and physiological responses of bryophytes to elevated temperature, increase in greenhouse gases, increased ultraviolet-B (UV-B) radiation, and fluctuations in humidity. In the light of this gathered global knowledge, possible species of bryophytes to be used in assessing and predicting climate change and developing a climate change model in Sri Lanka are proposed. Asian bryophytes, in general, have poorly been represented in climate change literature. We believe that this knowledge will form the foundation for future research focused on climate change mitigation in other tropical and Asian countries.
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Affiliation(s)
- Sumudu Ruklani
- Department of Botany, Faculty of Science, University of Peradeniya, Peradeniya, Kandy, 20400, Sri Lanka.
| | - Sumudu C K Rubasinghe
- Department of Botany, Faculty of Science, University of Peradeniya, Peradeniya, Kandy, 20400, Sri Lanka
| | - Gehan Jayasuriya
- Department of Botany, Faculty of Science, University of Peradeniya, Peradeniya, Kandy, 20400, Sri Lanka
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Ekwealor JTB, Clark TA, Dautermann O, Russell A, Ebrahimi S, Stark LR, Niyogi KK, Mishler BD. Natural ultraviolet radiation exposure alters photosynthetic biology and improves recovery from desiccation in a desert moss. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4161-4179. [PMID: 33595636 DOI: 10.1093/jxb/erab051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Plants in dryland ecosystems experience extreme daily and seasonal fluctuations in light, temperature, and water availability. We used an in situ field experiment to uncover the effects of natural and reduced levels of ultraviolet radiation (UV) on maximum PSII quantum efficiency (Fv/Fm), relative abundance of photosynthetic pigments and antioxidants, and the transcriptome in the desiccation-tolerant desert moss Syntrichia caninervis. We tested the hypotheses that: (i) S. caninervis plants undergo sustained thermal quenching of light [non-photochemical quenching (NPQ)] while desiccated and after rehydration; (ii) a reduction of UV will result in improved recovery of Fv/Fm; but (iii) 1 year of UV removal will de-harden plants and increase vulnerability to UV damage, indicated by a reduction in Fv/Fm. All field-collected plants had extremely low Fv/Fm after initial rehydration but recovered over 8 d in lab-simulated winter conditions. UV-filtered plants had lower Fv/Fm during recovery, higher concentrations of photoprotective pigments and antioxidants such as zeaxanthin and tocopherols, and lower concentrations of neoxanthin and Chl b than plants exposed to near natural UV levels. Field-grown S. caninervis underwent sustained NPQ that took days to relax and for efficient photosynthesis to resume. Reduction of solar UV radiation adversely affected recovery of Fv/Fm following rehydration.
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Affiliation(s)
- Jenna T B Ekwealor
- Department of Integrative Biology, and University and Jepson Herbaria, University of California, Berkeley, CA, USA
| | - Theresa A Clark
- School of Life Sciences, University of Nevada, Las Vegas, NV, USA
| | - Oliver Dautermann
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | | | - Sotodeh Ebrahimi
- School of Life Sciences, University of Nevada, Las Vegas, NV, USA
| | - Lloyd R Stark
- School of Life Sciences, University of Nevada, Las Vegas, NV, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Brent D Mishler
- Department of Integrative Biology, and University and Jepson Herbaria, University of California, Berkeley, CA, USA
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Huwe B, Fiedler A, Moritz S, Rabbow E, de Vera JP, Joshi J. Mosses in Low Earth Orbit: Implications for the Limits of Life and the Habitability of Mars. ASTROBIOLOGY 2019; 19:221-232. [PMID: 30742499 DOI: 10.1089/ast.2018.1889] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
As a part of the European Space Agency mission "EXPOSE-R2" on the International Space Station (ISS), the BIOMEX (Biology and Mars Experiment) experiment investigates the habitability of Mars and the limits of life. In preparation for the mission, experimental verification tests and scientific verification tests simulating different combinations of abiotic space- and Mars-like conditions were performed to analyze the resistance of a range of model organisms. The simulated abiotic space- and Mars-stressors were extreme temperatures, vacuum, and Mars-like surface ultraviolet (UV) irradiation in different atmospheres. We present for the first time simulated space exposure data of mosses using plantlets of the bryophyte genus Grimmia, which is adapted to high altitudinal extreme abiotic conditions at the Swiss Alps. Our preflight tests showed that severe UVR200-400nm irradiation with the maximal dose of 5 and 6.8 × 105 kJ·m-2, respectively, was the only stressor with a negative impact on the vitality with a 37% (terrestrial atmosphere) or 36% reduction (space- and Mars-like atmospheres) in photosynthetic activity. With every exposure to UVR200-400nm 105 kJ·m-2, the vitality of the bryophytes dropped by 6%. No effect was found, however, by any other stressor. As the mosses were still vital after doses of ultraviolet radiation (UVR) expected during the EXPOSE-R2 mission on ISS, we show that this earliest extant lineage of land plants is highly resistant to extreme abiotic conditions.
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Affiliation(s)
- Björn Huwe
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
| | - Annelie Fiedler
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
| | - Sophie Moritz
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
| | - Elke Rabbow
- 2 Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Jean Pierre de Vera
- 3 Astrobiological Laboratories, Management and Infrastructure, Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
| | - Jasmin Joshi
- 1 Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany
- 4 Institute for Landscape and Open Space, Hochschule für Technik HSR Rapperswil, Rapperswil, Switzerland
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Waterman MJ, Bramley-Alves J, Miller RE, Keller PA, Robinson SA. Photoprotection enhanced by red cell wall pigments in three East Antarctic mosses. Biol Res 2018; 51:49. [PMID: 30463628 PMCID: PMC6247747 DOI: 10.1186/s40659-018-0196-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 11/03/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Antarctic bryophytes (mosses and liverworts) are resilient to physiologically extreme environmental conditions including elevated levels of ultraviolet (UV) radiation due to depletion of stratospheric ozone. Many Antarctic bryophytes synthesise UV-B-absorbing compounds (UVAC) that are localised in their cells and cell walls, a location that is rarely investigated for UVAC in plants. This study compares the concentrations and localisation of intracellular and cell wall UVAC in Antarctic Ceratodon purpureus, Bryum pseudotriquetrum and Schistidium antarctici from the Windmill Islands, East Antarctica. RESULTS Multiple stresses, including desiccation and naturally high UV and visible light, seemed to enhance the incorporation of total UVAC including red pigments in the cell walls of all three Antarctic species analysed. The red growth form of C. purpureus had significantly higher levels of cell wall bound and lower intracellular UVAC concentrations than its nearby green form. Microscopic and spectroscopic analyses showed that the red colouration in this species was associated with the cell wall and that these red cell walls contained less pectin and phenolic esters than the green form. All three moss species showed a natural increase in cell wall UVAC content during the growing season and a decline in these compounds in new tissue grown under less stressful conditions in the laboratory. CONCLUSIONS UVAC and red pigments are tightly bound to the cell wall and likely have a long-term protective role in Antarctic bryophytes. Although the identity of these red pigments remains unknown, our study demonstrates the importance of investigating cell wall UVAC in plants and contributes to our current understanding of UV-protective strategies employed by particular Antarctic bryophytes. Studies such as these provide clues to how these plants survive in such extreme habitats and are helpful in predicting future survival of the species studied.
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Affiliation(s)
- Melinda J. Waterman
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
- Department of Chemistry and Biology, University of Santiago, Alameda, 3363 Santiago, Chile
| | - Jessica Bramley-Alves
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
| | - Rebecca E. Miller
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
- School of Ecosystem and Forest Sciences, University of Melbourne, Richmond, VIC 3121 Australia
| | - Paul A. Keller
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Sharon A. Robinson
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
- Department of Chemistry and Biology, University of Santiago, Alameda, 3363 Santiago, Chile
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Hui R, Zhao R, Song G, Li Y, Zhao Y, Wang Y. Effects of enhanced ultraviolet-B radiation, water deficit, and their combination on UV-absorbing compounds and osmotic adjustment substances in two different moss species. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:14953-14963. [PMID: 29549614 DOI: 10.1007/s11356-018-1689-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 03/04/2018] [Indexed: 06/08/2023]
Abstract
A simulation experiment was conducted to explore the influence of enhanced ultraviolet-B (UV-B) radiation, water deficit, and their combination on UV-absorbing compounds and osmotic adjustment substances of mosses Bryum argenteum and Didymodon vinealis isolated from biological soil crusts (BSCs) growing in a revegetated area of the Tengger Desert, China. Four levels of UV-B radiation and two gradients of water regime were employed. Compared with their controls, amounts of total flavonoids, chlorophyll, carotenoids, soluble sugars, and soluble proteins significantly decreased (p < 0.05), but proline content significantly increased (p < 0.05), when exposed to either enhanced UV-B or water deficit. The negative effects of enhanced UV-B were alleviated when water deficit was applied. There were increases in UV-absorbing compounds and osmotic adjustment substances when exposed to a combination of enhanced UV-B and water deficit compared with single stresses, except for the proline content in D. vinealis. In addition, our results also indicated interspecific differences in response to enhanced UV-B, water deficit, and their combination. Compared with B. argenteum, D. vinealis was more resistant to enhanced UV-B and water deficit singly and in combination. These results suggest that the damage of enhanced UV-B on both species might be alleviated by water deficit. This alleviation is important for understanding the response of BSCs to UV-B radiation in future global climate change. This also provides novel insights into assessment damages of UV-B to BSC stability in arid and semiarid regions.
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Affiliation(s)
- Rong Hui
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Road 320, 730000, Lanzhou, Gansu, People's Republic of China.
| | - Ruiming Zhao
- School of Life Sciences, Lanzhou University, Tianshui South Road 222, 730000, Lanzhou, People's Republic of China
| | - Guang Song
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Road 320, 730000, Lanzhou, Gansu, People's Republic of China
| | - Yixuan Li
- College of Agronomy, Shenyang Agricultural University, Dongling Road 120, 10866, Shenyang, Liaoning Province, People's Republic of China
| | - Yang Zhao
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Road 320, 730000, Lanzhou, Gansu, People's Republic of China
| | - Yanli Wang
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Road 320, 730000, Lanzhou, Gansu, People's Republic of China
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Waterman MJ, Nugraha AS, Hendra R, Ball GE, Robinson SA, Keller PA. Antarctic Moss Biflavonoids Show High Antioxidant and Ultraviolet-Screening Activity. JOURNAL OF NATURAL PRODUCTS 2017; 80:2224-2231. [PMID: 28783339 DOI: 10.1021/acs.jnatprod.7b00085] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ceratodon purpureus is a cosmopolitan moss that survives some of the harshest places on Earth: from frozen Antarctica to hot South Australian deserts. In a study on the survival mechanisms of the species, nine compounds were isolated from Australian and Antarctic C. purpureus. This included five biflavonoids, with complete structural elucidation of 1 and 2 reported here for the first time, as well as an additional four known phenolic compounds. Dispersion-corrected DFT calculations suggested a rotational barrier, leading to atropisomerism, resulting in the presence of diastereomers for compound 2. All isolates absorbed strongly in the ultraviolet (UV) spectrum, e.g., biflavone 1 (UV-A, 315-400 nm), which displayed the strongest radical-scavenging activity, 13% more efficient than the standard rutin; p-coumaric acid and trans-ferulic acid showed the highest UV-B (280-315 nm) absorption. The more complex and abundant 1 and 2 presumably have dual roles as both UV-screening and antioxidant compounds. They are strongly bound to Antarctic moss cell walls as well as located inside the cells of moss from both locations. The combined high stability and photoprotective abilities of these isolates may account for the known resilience of this species to UV-B radiation and its survival in some of the toughest locations in the world.
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Affiliation(s)
| | | | | | - Graham E Ball
- School of Chemistry, UNSW , Sydney, NSW 2052, Australia
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10
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Monforte L, Tomás-Las-Heras R, Del-Castillo-Alonso MÁ, Martínez-Abaigar J, Núñez-Olivera E. Spatial variability of ultraviolet-absorbing compounds in an aquatic liverwort and their usefulness as biomarkers of current and past UV radiation: a case study in the Atlantic-Mediterranean transition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 518-519:248-57. [PMID: 25765377 DOI: 10.1016/j.scitotenv.2015.03.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/26/2015] [Accepted: 03/02/2015] [Indexed: 05/24/2023]
Abstract
The spatial variability of ultraviolet-absorbing compounds (UVACs) in the freshwater liverwort Jungermannia exsertifolia subsp. cordifolia was studied in mid-latitudes (the Atlantic-Mediterranean transition) across a wide lati-altitudinal gradient, with the aim of testing the usefulness of UVACs as biomarkers of current ambient levels of UV radiation. We analysed 17 samples from streams located in the main mountain ranges of the Iberian Peninsula, differentiating methanol-soluble (SUVACs, mainly located in the vacuoles) and methanol-insoluble (IUVACs, bound to cell walls) compounds, since they represent different manners to cope with UV radiation. In both fractions, the bulk level of UVACs and the concentrations of several individual compounds were measured. In addition, we measured Fv/Fm, DNA damage and sclerophylly index (SI) as possible additional UV biomarkers. UVACs showed a high variability, probably due not only to the gradients of macroenvironmental factors (UV radiation, PAR, and water temperature), but also to microenvironmental factors inherent to the dynamic nature of mountain streams. Two soluble coumarins were positively correlated with UV levels and could be used for ambient UV biomonitoring in the spatial scale. In contrast to the variability in UVACs, the relatively homogeneous values of Fv/Fm and the lack of any DNA damage made these variables useless for ambient UV biomonitoring, but suggested a strong acclimation capacity of this liverwort to changing environmental conditions (in particular, to UV levels). Finally, UVACs of fresh samples of the liverwort were compared to those of herbarium samples collected in the same lati-altitudinal gradient. SUVACs were significantly higher in fresh samples, whereas IUVACs generally showed the contrary. Thus, IUVACs were more stable than SUVACs and hence more adequate for retrospective UV biomonitoring. In conclusion, UVAC compartmentation should be taken into account for bryophyte-based UV biomonitoring in future studies.
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Affiliation(s)
- Laura Monforte
- Edificio Científico-Tecnológico, Universidad de La Rioja, Avda. Madre de Dios 51, E-26006 Logroño, Spain
| | - Rafael Tomás-Las-Heras
- Edificio Científico-Tecnológico, Universidad de La Rioja, Avda. Madre de Dios 51, E-26006 Logroño, Spain
| | | | - Javier Martínez-Abaigar
- Edificio Científico-Tecnológico, Universidad de La Rioja, Avda. Madre de Dios 51, E-26006 Logroño, Spain.
| | - Encarnación Núñez-Olivera
- Edificio Científico-Tecnológico, Universidad de La Rioja, Avda. Madre de Dios 51, E-26006 Logroño, Spain
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Robinson SA, Erickson DJ. Not just about sunburn--the ozone hole's profound effect on climate has significant implications for Southern Hemisphere ecosystems. GLOBAL CHANGE BIOLOGY 2015; 21:515-527. [PMID: 25402975 DOI: 10.1111/gcb.12739] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 08/23/2014] [Accepted: 08/31/2014] [Indexed: 06/04/2023]
Abstract
Climate scientists have concluded that stratospheric ozone depletion has been a major driver of Southern Hemisphere climate processes since about 1980. The implications of these observed and modelled changes in climate are likely to be far more pervasive for both terrestrial and marine ecosystems than the increase in ultraviolet-B radiation due to ozone depletion; however, they have been largely overlooked in the biological literature. Here, we synthesize the current understanding of how ozone depletion has impacted Southern Hemisphere climate and highlight the relatively few documented impacts on terrestrial and marine ecosystems. Reviewing the climate literature, we present examples of how ozone depletion changes atmospheric and oceanic circulation, with an emphasis on how these alterations in the physical climate system affect Southern Hemisphere weather, especially over the summer season (December-February). These potentially include increased incidence of extreme events, resulting in costly floods, drought, wildfires and serious environmental damage. The ecosystem impacts documented so far include changes to growth rates of South American and New Zealand trees, decreased growth of Antarctic mosses and changing biodiversity in Antarctic lakes. The objective of this synthesis was to stimulate the ecological community to look beyond ultraviolet-B radiation when considering the impacts of ozone depletion. Such widespread changes in Southern Hemisphere climate are likely to have had as much or more impact on natural ecosystems and food production over the past few decades, than the increased ultraviolet radiation due to ozone depletion.
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Affiliation(s)
- Sharon A Robinson
- Institute for Conservation Biology, School of Biological Sciences, The University of Wollongong, Wollongong, New South Wales, 2522, Australia
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Bornman JF, Barnes PW, Robinson SA, Ballaré CL, Flint SD, Caldwell MM. Solar ultraviolet radiation and ozone depletion-driven climate change: effects on terrestrial ecosystems. Photochem Photobiol Sci 2015; 14:88-107. [DOI: 10.1039/c4pp90034k] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We summarise advances in our knowledge of how UV-B radiation (280–315 nm) together with other climate change factors interact in their influence on terrestrial organisms and ecosystems.
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Affiliation(s)
- J. F. Bornman
- International Institute of Agri-Food Security (IIAFS)
- Curtin University
- Perth
- Australia
| | - P. W. Barnes
- Department of Biological Sciences and Environment Program
- Loyola University New Orleans
- New Orleans
- USA
| | - S. A. Robinson
- Institute for Conservation Biology
- School of Biological Sciences
- The University of Wollongong
- New South Wales 2522
- Australia
| | - C. L. Ballaré
- IFEVA Universidad de Buenos Aires and IIB Universidad Nacional de San Martín
- Consejo Nacional de Investigaciones Científicas y Técnicas
- C1417DSE Buenos Aires
- Argentina
| | - S. D. Flint
- Department of Forest
- Rangeland
- and Fire Sciences
- University of Idaho
- Moscow
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Convey P, Chown SL, Clarke A, Barnes DKA, Bokhorst S, Cummings V, Ducklow HW, Frati F, Green TGA, Gordon S, Griffiths HJ, Howard-Williams C, Huiskes AHL, Laybourn-Parry J, Lyons WB, McMinn A, Morley SA, Peck LS, Quesada A, Robinson SA, Schiaparelli S, Wall DH. The spatial structure of Antarctic biodiversity. ECOL MONOGR 2014. [DOI: 10.1890/12-2216.1] [Citation(s) in RCA: 232] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Pescheck F, Lohbeck KT, Roleda MY, Bilger W. UVB-induced DNA and photosystem II damage in two intertidal green macroalgae: distinct survival strategies in UV-screening and non-screening Chlorophyta. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 132:85-93. [PMID: 24602816 DOI: 10.1016/j.jphotobiol.2014.02.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 01/29/2014] [Accepted: 02/04/2014] [Indexed: 12/17/2022]
Abstract
Ultraviolet-B-induced (UVB, 280-315 nm) accumulation of cyclobutane pyrimidine dimers (CPDs) and deactivation of photosystem II (PS II) was quantified in two intertidal green macroalgae, Ulva clathrata and Rhizoclonium riparium. The species were chosen due to their shared habitats but contrasting UVB screening potentials. In the non-screening U. clathrata CPDs accumulated and PS II activity declined as a linear function of applied UVB irradiance. In R. riparium UVB-induced damage was significantly lower than in U. clathrata, demonstrating an efficient UVB protection of DNA and PS II by screening. Based on the UVB irradiance reaching the chloroplasts, both species showed an identical intrinsic sensitivity of PS II towards UVB, but DNA lesions accumulated slower in U. clathrata. While repair of CPDs was similar in both species, U. clathrata was capable of restoring its PS II function decidedly faster than R. riparium. In R. riparium efficient screening may represent an adaptation to its high light habitat, whereas in U. clathrata high repair rates of PS II appear to be important to survive natural UVB exposure. The role of shading of the nucleus by the large chloroplasts in U. clathrata is discussed.
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Affiliation(s)
- Frauke Pescheck
- Botanical Institute, Christian-Albrechts-University Kiel, Olshausenstr. 40, 24098 Kiel, Germany.
| | - Kai T Lohbeck
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Michael Y Roleda
- Institute for Polar Ecology, Christian-Albrechts-University Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany; Bioforsk Norwegian Institute for Agricultural and Environmental Research, Kudalsveien 6, 8049 Bodø, Norway
| | - Wolfgang Bilger
- Botanical Institute, Christian-Albrechts-University Kiel, Olshausenstr. 40, 24098 Kiel, Germany
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Robinson SA, Waterman MJ. Sunsafe Bryophytes: Photoprotection from Excess and Damaging Solar Radiation. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-007-6988-5_7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Raven JA, Edwards D. Photosynthesis in Early Land Plants: Adapting to the Terrestrial Environment. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-007-6988-5_3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Bramley-Alves J, King DH, Robinson SA, Miller RE. Dominating the Antarctic Environment: Bryophytes in a Time of Change. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-007-6988-5_17] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Arróniz-Crespo M, Gwynn-Jones D, Callaghan TV, Núñez-Olivera E, Martínez-Abaigar J, Horton P, Phoenix GK. Impacts of long-term enhanced UV-B radiation on bryophytes in two sub-Arctic heathland sites of contrasting water availability. ANNALS OF BOTANY 2011; 108:557-65. [PMID: 21803739 PMCID: PMC3158694 DOI: 10.1093/aob/mcr178] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 05/23/2011] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS Anthropogenic depletion of stratospheric ozone in Arctic latitudes has resulted in an increase of ultraviolet-B radiation (UV-B) reaching the biosphere. UV-B exposure is known to reduce above-ground biomass and plant height, to increase DNA damage and cause accumulation of UV-absorbing compounds in polar plants. However, many studies on Arctic mosses tended to be inconclusive. The importance of different water availability in influencing UV-B impacts on lower plants in the Arctic has been poorly explored and might partially explain the observed wide variation of responses, given the importance of water in controlling bryophyte physiology. This study aimed to assess the long-term responses of three common sub-Arctic bryophytes to enhanced UV-B radiation (+UV-B) and to elucidate the influence of water supply on those responses. METHODS Responses of three sub-Arctic bryophytes (the mosses Hylocomium splendens and Polytrichum commune and the liverwort Barbilophozia lycopodioides) to +UV-B for 15 and 13 years were studied in two field experiments using lamps for UV-B enhancement with identical design and located in neighbouring areas with contrasting water availability (naturally mesic and drier sites). Responses evaluated included bryophyte abundance, growth, sporophyte production and sclerophylly; cellular protection by accumulation of UV-absorbing compounds, β-carotene, xanthophylls and development of non-photochemical quenching (NPQ); and impacts on photosynthesis performance by maximum quantum yield (F(v) /F(m)) and electron transport rate (ETR) through photosystem II (PSII) and chlorophyll concentrations. RESULTS Responses were species specific: H. splendens responded most to +UV-B, with reduction in both annual growth (-22 %) and sporophyte production (-44 %), together with increased β-carotene, violaxanthin, total chlorophyll and NPQ, and decreased zeaxanthin and de-epoxidation of the xanthophyll cycle pool (DES). Barbilophozia lycopodioides responded less to +UV-B, showing increased β-carotene and sclerophylly and decreased UV-absorbing compounds. Polytrichum commune only showed small morphogenetic changes. No effect of UV-B on bryophyte cover was observed. Water availability had profound effects on bryophyte ecophysiology, and plants showed, in general, lower growth and ETR, together with a higher photoprotection in the drier site. Water availability also influenced bryophyte responses to +UV-B and, in particular, responses were less detectable in the drier site. CONCLUSIONS Impacts of UV-B exposure on Arctic bryophytes were significant, in contrast to modest or absent UV-B effects measured in previous studies. The impacts were more easily detectable in species with high plasticity such as H. splendens and less obvious, or more subtle, under drier conditions. Species biology and water supply greatly influences the impact of UV-B on at least some Arctic bryophytes and could contribute to the wide variation of responses observed previously.
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Affiliation(s)
- M Arróniz-Crespo
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
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Ballaré CL, Caldwell MM, Flint SD, Robinson SA, Bornman JF. Effects of solar ultraviolet radiation on terrestrial ecosystems. Patterns, mechanisms, and interactions with climate change. Photochem Photobiol Sci 2011; 10:226-41. [DOI: 10.1039/c0pp90035d] [Citation(s) in RCA: 277] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Fabón G, Martínez-Abaigar J, Tomás R, Núñez-Olivera E. Effects of enhanced UV-B radiation on hydroxycinnamic acid derivatives extracted from different cell compartments in the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia. PHYSIOLOGIA PLANTARUM 2010; 140:269-279. [PMID: 20663084 DOI: 10.1111/j.1399-3054.2010.01401.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We examined the responses of ultraviolet-absorbing compounds (UVAC) to enhanced UV-B radiation in the aquatic liverwort Jungermannia exsertifolia subsp. cordifolia for 31 days under laboratory conditions. Samples were exposed to three radiation regimes: P (only photosynthetic radiation), PA (photosynthetic + UV-A radiation) and PAB (photosynthetic + UV-A + UV-B radiation). We measured both the bulk UV absorbance of the methanolic extracts and the levels of individual UVAC. In both cases, the methanol-soluble and the methanol-insoluble, alkali-extractable cell wall-bound fractions were analyzed. The bulk UV absorbance of the soluble fraction was higher than that of the cell wall-bound fraction. The bulk UV absorbances of both fractions increased under enhanced UV-B (PAB regime). Five different hydroxycinnamic acid (HCA) derivatives were found in the soluble fraction and two additional ones in the cell wall-bound fraction, among which only p-coumaroylmalic acid in the soluble fraction and p-coumaric acid in the cell wall-bound fraction increased under enhanced UV-B. The maximum quantum yield of PSII (F(v) /F(m)) decreased and DNA damage (amount of thymine dimers) strongly increased under enhanced UV-B, showing UV-B-induced damage. We conclude that methanol-soluble and cell wall-bound fractions of the liverwort studied have different UVAC, and each individual compound may respond in a different way to UV-B radiation. Thus, the analysis of individual UVAC in both the methanol-soluble and cell wall-bound fractions is advisable to better evaluate the protection mechanisms of liverworts against UV-B radiation. In particular, p-coumaric acid and p-coumaroylmalic acid seem to be especially UV-B responsive and merit further investigation.
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Affiliation(s)
- Gabriel Fabón
- Complejo Científico-Tecnológico, Universidad de La Rioja, Avda. Madre de Dios 51, 26006 Logroño (La Rioja), Spain
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Andrady A, Aucamp PJ, Bais AF, Ballaré CL, Björn LO, Bornman JF, Caldwell M, Cullen AP, Erickson DJ, deGruijl FR, Häder DP, Ilyas M, Kulandaivelu G, Kumar HD, Longstreth J, McKenzie RL, Norval M, Paul N, Redhwi HH, Smith RC, Solomon KR, Sulzberger B, Takizawa Y, Tang X, Teramura AH, Torikai A, van der Leun JC, Wilson SR, Worrest RC, Zepp RG. Environmental effects of ozone depletion and its interactions with climate change: progress report, 2009. Photochem Photobiol Sci 2010; 9:275-94. [PMID: 20301813 DOI: 10.1039/b923342n] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The parties to the Montreal Protocol are informed by three panels of experts. One of these is the Environmental Effects Assessment Panel (EEAP), which deals with UV radiation and its effects on human health, animals, plants, biogeochemistry, air quality and materials. Since 2000, the analyses and interpretation of these effects have included interactions between UV radiation and global climate change. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than believed previously. As a result of this, human health and environmental problems will likely be longer-lasting and more regionally variable. Like the other panels, the EEAP produces a detailed report every four years; the most recent was that for 2006 (Photochem. Photobiol. Sci., 2007, 6, 201-332). In the years in between, the EEAP produces a less detailed and shorter progress report, as is the case for this present one for 2009. A full quadrennial report will follow for 2010.
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