1
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Kono M, Matsuzawa S, Noguchi T, Miyata K, Oguchi R, Terashima I. A new method for separate evaluation of PSII with inactive oxygen evolving complex and active D1 by the pulse-amplitude modulated chlorophyll fluorometry. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:542-553. [PMID: 34511179 DOI: 10.1071/fp21073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
A method that separately quantifies the PSII with inactive oxygen-evolving complex (OEC) and active D1 retaining the primary quinone acceptor (QA )-reducing activity from the PSII with damaged D1 in the leaf was developed using PAM fluorometry. It is necessary to fully reduce QA to obtain F m , the maximum fluorescence. However, QA in PSII with inactive OEC and active D1 would not be fully reduced by a saturating flash. We used the acceptor-side inhibitor DCMU to fully reduce QA . Leaves of cucumber (Cucumis sativus L.) were chilled at 4°C in dark or illuminated with UV-A to selectively inactivate OEC. After these treatments, F v /F m , the maximum quantum yield, in the leaves vacuum-infiltrated with DCMU were greater than those in water-infiltrated leaves. In contrast, when the leaves were illuminated by red light to photodamage D1, F v /F m did not differ between DCMU- and water-infiltrated leaves. These results indicate relevance of the present evaluation of the fraction of PSII with inactive OEC and active D1. Several examinations in the laboratory and glasshouse showed that PSII with inactive OEC and active D1 was only rarely observed. The present simple method would serve as a useful tool to clarify the details of the PSII photoinhibition.
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Affiliation(s)
- Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; and Corresponding author
| | - Sae Matsuzawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takaya Noguchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazunori Miyata
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Riichi Oguchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ichiro Terashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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2
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Ludovici GM, Oliveira de Souza S, Chierici A, Cascone MG, d'Errico F, Malizia A. Adaptation to ionizing radiation of higher plants: From environmental radioactivity to chernobyl disaster. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 222:106375. [PMID: 32791372 DOI: 10.1016/j.jenvrad.2020.106375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
The purpose of this work is to highlight the effects of ionizing radiation on the genetic material in higher plants by assessing both adaptive processes as well as the evolution of plant species. The effects that the ionizing radiation has on greenery following a nuclear accident, was examined by taking the Chernobyl Nuclear Power Plant disaster as a case study. The genetic and evolutionary effects that ionizing radiation had on plants after the Chernobyl accident were highlighted. The response of biota to Chernobyl irradiation was a complex interaction among radiation dose, dose rate, temporal and spatial variation, varying radiation sensitivities of the different plants' species, and indirect effects from other events. Ionizing radiation causes water radiolysis, generating highly reactive oxygen species (ROS). ROS induce the rapid activation of detoxifying enzymes. DeoxyriboNucleic Acid (DNA) is the object of an attack by both, the hydroxyl ions and the radiation itself, thus triggering a mechanism both direct and indirect. The effects on DNA are harmful to the organism and the long-term development of the species. Dose-dependent aberrations in chromosomes are often observed after irradiation. Although multiple DNA repair mechanisms exist, double-strand breaks (DSBs or DNA-DSBs) are often subject to errors. Plants DSBs repair mechanisms mainly involve homologous and non-homologous dependent systems, the latter especially causing a loss of genetic information. Repeated ionizing radiation (acute or chronic) ensures that plants adapt, demonstrating radioresistance. An adaptive response has been suggested for this phenomenon. As a result, ionizing radiation influences the genetic structure, especially during chronic irradiation, reducing genetic variability. This reduction may be associated with the fact that particular plant species are more subject to chronic stress, confirming the adaptive theory. Therefore, the genomic effects of ionizing radiation demonstrate their likely involvement in the evolution of plant species.
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Affiliation(s)
| | | | - Andrea Chierici
- Department of Industrial Engineering, University of Rome Tor Vergata, Italy; Department of Civil and Industrial Engineering, University of Pisa, Italy
| | | | - Francesco d'Errico
- Department of Civil and Industrial Engineering, University of Pisa, Italy
| | - Andrea Malizia
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Italy.
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3
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Tabra K, Arellano EC, Contreras S, Ginocchio R. Evaluation of phytotoxic effects of cationic polyacrylamide polymers: implication for the use of sludges as organic soil amendments in assisted phytostabilization. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2020; 22:1068-1074. [PMID: 32129081 DOI: 10.1080/15226514.2020.1726870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sludges, as biosolids, are organic soil amendments commonly used in assisted phytostabilitation. Extensive studies on their environmental impacts exists, particularly for improper land application and contents of trace elements, organic compounds and pathogens, but not for their content of cationic polyacrylamide polymers (C-PAMs). Direct toxicity of C-PAMs on aquatic organisms has been demonstrated but scarce information about plant toxicity is available. In this study, the effect of C-PAMs on early plant growth was evaluated by means of standard toxicity assays. Firstly, increasing doses of C-PAMs were applied as solutions to seeds of Avena sativa, Lactuca sativa and Solanum lycopersycum to evaluate germination and root elongation. Secondly, the effect of increasing doses of C-PAMs spiked in pig manure and mixed with sand (75 t ha-1 dry base) was evaluated on the emergence, radicle elongation and biomass of A. sativa. Results showed high phytotoxicity of C-PAMs in solutions above 1,000 mg L-1, but no effect was detected when spiked into experimental substrate; a significant effect was only observed above 5,000 mg L-1 for radicle elongation, aerial biomass, and radicle biomass. Results demonstrate direct phytotoxic effects of C-PAMs, which can be mitigated when spiked into an organic (pig manure) and mineral (sand) matrix.
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Affiliation(s)
- Kathia Tabra
- Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo C Arellano
- Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Samuel Contreras
- Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rosanna Ginocchio
- Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile
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4
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Seddon AWR, Festi D, Robson TM, Zimmermann B. Fossil pollen and spores as a tool for reconstructing ancient solar-ultraviolet irradiance received by plants: an assessment of prospects and challenges using proxy-system modelling. Photochem Photobiol Sci 2019; 18:275-294. [PMID: 30649121 DOI: 10.1039/c8pp00490k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Ultraviolet-B radiation (UV-B, 280-315 nm) constitutes less than 1% of the total solar radiation that reaches the Earth's surface but has a disproportional impact on biological and ecological processes from the individual to the ecosystem level. Absorption of UV-B by ozone is also one of the primary heat sources to the stratosphere, so variations in UV-B have important relationships to the Earth's radiation budget. Yet despite its importance for understanding atmospheric and ecological processes, there is limited understanding about the changes in UV-B radiation in the geological past. This is because systematic measurements of total ozone and surface UV-B only exist since the 1970s, so biological or geochemical proxies from sediment archives are needed to reconstruct UV-B irradiance received at the Earth surface beyond the experimental record. Recent developments have shown that the quantification of UV-B-absorbing compounds in pollen and spores have the potential to provide a continuous record of the solar-ultraviolet radiation received by plants. There is increasing interest in developing this proxy in palaeoclimatic and palaeoecological research. However, differences in interpretation exist between palaeoecologists, who are beginning to apply the proxy under various geological settings, and UV-B ecologists, who question whether a causal dose-response relationship of pollen and spore chemistry to UV-B irradiance has really been established. Here, we use a proxy-system modelling approach to systematically assess components of the pollen- and spore-based UV-B-irradiance proxy to ask how these differences can be resolved. We identify key unknowns and uncertainties in making inferences about past UV-B irradiance, from the pollen sensor, the sedimentary archive, and through the laboratory and experimental procedures in order to target priority areas of future work. We argue that an interdisciplinary approach, modifying methods used by plant ecologists studying contemporary responses to solar-UV-B radiation specifically to suit the needs of palaeoecological analyses, provides a way forward in developing the most reliable reconstructions for the UV-B irradiance received by plants across a range of timescales.
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Affiliation(s)
- Alistair W R Seddon
- Department of Biological Sciences, University of Bergen, Norway. .,Bjerknes Centre for Climate Research, University of Bergen, Norway.
| | - Daniela Festi
- Department of Botany, University of Innsbruck, Austria.,Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
| | - T Matthew Robson
- Organismal and Evolutionary Biology (OEB), Viikki Plant Science Centre (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Boris Zimmermann
- Faculty of Science and Technology, Norwegian University of Life Sciences, Norway
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5
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Wang QW, Daumal M, Nagano S, Yoshida N, Morinaga SI, Hikosaka K. Plasticity of functional traits and optimality of biomass allocation in elevational ecotypes of Arabidopsis halleri grown at different soil nutrient availabilities. JOURNAL OF PLANT RESEARCH 2019; 132:237-249. [PMID: 30721383 DOI: 10.1007/s10265-019-01088-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
In mountainous areas, plant distribution is constrained by various environmental stresses. Plasticity and constancy in plant functional traits may relate to optimal strategies at respective habitats and to ecotypic differentiation along elevation. Although plant biomass allocation has been extensively studied in relation to adaptation to soil nutrient availability along elevation, its optimality is still poorly understood. We examined soil nutrient availability in the field and conducted growth analysis for two elevational ecotypes of Arabidopsis halleri grown under different nutrient availabilities. We determined plasticity in morphological and physiological traits and evaluated optimal biomass allocation using an optimality model. Our field investigation indicated that soil nitrogen (N) availability increased rather than decreased with increasing elevation. Our growth analysis revealed that lowland ecotype was more plastic in morphological variables and N concentrations, whereas the highland ecotype was more plastic in other physiological variables such as the net assimilation rate (NAR). The leaf mass ratio (LMR) in the lowland ecotype was moderately plastic at the whole range of N availabilities, whereas LMR in the highland ecotype was very plastic at higher N availabilities only. The optimality model indicated that the LMR of the lowland ecotype was nearly optimal throughout the range of studied N availabilities, whereas that of the highland ecotype was suboptimal at low N availability. These results suggest that highland ecotype is adapted only to high N availability, whereas the lowland ecotype is adapted to a relatively wide range of N availabilities as a result of natural selection in their respective habitats. We conclude that an adaptive differentiation has occurred between the two ecotypes and plasticity in the biomass allocation is directly related to its optimization in changing environments.
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Affiliation(s)
- Qing-Wei Wang
- Graduate School of Life Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan.
- Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan.
| | - Maya Daumal
- Graduate School of Life Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan
| | - Soichiro Nagano
- Forest Tree Breeding Center, Forestry and Forest Products Research Institute, 3809-1 Ishi, Juo, Hitachi, Ibaraki, 319-1301, Japan
| | - Naofumi Yoshida
- Faculty of Science, Tohoku University, Aoba, Sendai, 980-8578, Japan
| | - Shin-Ichi Morinaga
- College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Kouki Hikosaka
- Graduate School of Life Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan
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6
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Bornman JF, Barnes PW, Robson TM, Robinson SA, Jansen MAK, Ballaré CL, Flint SD. Linkages between stratospheric ozone, UV radiation and climate change and their implications for terrestrial ecosystems. Photochem Photobiol Sci 2019; 18:681-716. [DOI: 10.1039/c8pp90061b] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Linkages between stratospheric ozone, UV radiation and climate change: terrestrial ecosystems.
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Affiliation(s)
- Janet F. Bornman
- College of Science
- Health
- Engineering and Education
- Murdoch University
- Perth
| | - Paul W. Barnes
- Department of Biological Sciences and Environment Program
- Loyola University
- USA
| | - T. Matthew Robson
- Research Programme in Organismal and Evolutionary Biology
- Viikki Plant Science Centre
- University of Helsinki
- Finland
| | - Sharon A. Robinson
- Centre for Sustainable Ecosystem Solutions
- School of Earth
- Atmosphere and Life Sciences and Global Challenges Program
- University of Wollongong
- Wollongong
| | - Marcel A. K. Jansen
- Plant Ecophysiology Group
- School of Biological
- Earth and Environmental Sciences
- UCC
- Cork
| | - Carlos L. Ballaré
- University of Buenos Aires
- Faculty of Agronomy and IFEVA-CONICET, and IIB
- National University of San Martin
- Buenos Aires
- Argentina
| | - Stephan D. Flint
- Department of Forest
- Rangeland and Fire Sciences
- University of Idaho
- Moscow
- USA
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7
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Bais F, Luca RM, Bornman JF, Williamson CE, Sulzberger B, Austin AT, Wilson SR, Andrady AL, Bernhard G, McKenzie RL, Aucamp PJ, Madronich S, Neale RE, Yazar S, Young AR, de Gruijl FR, Norval M, Takizawa Y, Barnes PW, Robson TM, Robinson SA, Ballaré CL, Flint SD, Neale PJ, Hylander S, Rose KC, Wängberg SÅ, Häder DP, Worrest RC, Zepp RG, Paul ND, Cory RM, Solomon KR, Longstreth J, Pandey KK, Redhwi HH, Torikai A, Heikkilä AM. Environmental effects of ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2017. Photochem Photobiol Sci 2018; 17:127-179. [PMID: 29404558 PMCID: PMC6155474 DOI: 10.1039/c7pp90043k] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 12/21/2017] [Indexed: 12/11/2022]
Abstract
The Environmental Effects Assessment Panel (EEAP) is one of three Panels of experts that inform the Parties to the Montreal Protocol. The EEAP focuses on the effects of UV radiation on human health, terrestrial and aquatic ecosystems, air quality, and materials, as well as on the interactive effects of 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 previously held. Because of the Montreal Protocol, there are now indications of the beginnings of a recovery of stratospheric ozone, although the time required to reach levels like those before the 1960s is still uncertain, particularly as the effects of stratospheric ozone on climate change and vice versa, are not yet fully understood. Some regions will likely receive enhanced levels of UV radiation, while other areas will likely experience a reduction in UV radiation as ozone- and climate-driven changes affect the amounts of UV radiation reaching the Earth's surface. Like the other Panels, the EEAP produces detailed Quadrennial Reports every four years; the most recent was published as a series of seven papers in 2015 (Photochem. Photobiol. Sci., 2015, 14, 1-184). In the years in between, the EEAP produces less detailed and shorter Update Reports of recent and relevant scientific findings. The most recent of these was for 2016 (Photochem. Photobiol. Sci., 2017, 16, 107-145). The present 2017 Update Report assesses some of the highlights and new insights about the interactive nature of the direct and indirect effects of UV radiation, atmospheric processes, and climate change. A full 2018 Quadrennial Assessment, will be made available in 2018/2019.
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Affiliation(s)
- F. Bais
- Aristotle Univ. of Thessaloniki, Laboratory of Atmospheric Physics, Thessaloniki, Greece
| | - R. M. Luca
- National Centre for Epidemiology and Population Health, Australian National Univ., Canberra, Australia
| | - J. F. Bornman
- Curtin Univ., Curtin Business School, Perth, Australia
| | | | - B. Sulzberger
- Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - A. T. Austin
- Univ. of Buenos Aires, Faculty of Agronomy and IFEVA-CONICET, Buenos Aires, Argentina
| | - S. R. Wilson
- School of Chemistry, Centre for Atmospheric Chemistry, Univ. of Wollongong, Wollongong, Australia
| | - A. L. Andrady
- Department of Chemical and Biomolecular Engineering, North Carolina State Univ., Raleigh, NC, USA
| | - G. Bernhard
- Biospherical Instruments Inc., San Diego, CA, USA
| | | | - P. J. Aucamp
- Ptersa Environmental Consultants, Faerie Glen, South Africa
| | - S. Madronich
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - R. E. Neale
- Queensland Institute of Medical Research, Royal Brisbane Hospital, Brisbane, Australia
| | - S. Yazar
- Univ. of Western Australia, Centre for Ophthalmology and Visual Science, Lions Eye Institute, Perth, Australia
| | | | - F. R. de Gruijl
- Department of Dermatology, Leiden Univ. Medical Centre, Leiden, The Netherlands
| | - M. Norval
- Univ. of Edinburgh Medical School, UK
| | - Y. Takizawa
- Akita Univ. School of Medicine, National Institute for Minamata Disease, Nakadai, Itabashiku, Tokyo, Japan
| | - P. W. Barnes
- Department of Biological Sciences and Environment Program, Loyola Univ., New Orleans, USA
| | - T. M. Robson
- Research Programme in Organismal and Evolutionary Biology, Viikki Plant Science Centre, Univ. of Helsinki, Finland
| | - S. A. Robinson
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, Univ. of Wollongong, Wollongong, NSW 2522, Australia
| | - C. L. Ballaré
- Univ. of Buenos Aires, Faculty of Agronomy and IFEVA-CONICET, Buenos Aires, Argentina
| | - S. D. Flint
- Dept of Forest, Rangeland and Fire Sciences, Univ. of Idaho, Moscow, ID, USA
| | - P. J. Neale
- Smithsonian Environmental Research Center, Edgewater, Maryland, USA
| | - S. Hylander
- Centre for Ecology and Evolution in Microbial model Systems, Linnaeus Univ., Kalmar, Sweden
| | - K. C. Rose
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - S.-Å. Wängberg
- Dept Marine Sciences, Univ. of Gothenburg, Göteborg, Sweden
| | - D.-P. Häder
- Friedrich-Alexander Univ. Erlangen-Nürnberg, Dept of Biology, Möhrendorf, Germany
| | - R. C. Worrest
- CIESIN, Columbia Univ., New Hartford, Connecticut, USA
| | - R. G. Zepp
- United States Environmental Protection Agency, Athens, Georgia, USA
| | - N. D. Paul
- Lanter Environment Centre, Lanter Univ., LA1 4YQ, UK
| | - R. M. Cory
- Earth and Environmental Sciences, Univ. of Michigan, Ann Arbor, MI, USA
| | - K. R. Solomon
- Centre for Toxicology, School of Environmental Sciences, Univ. of Guelph, Guelph, ON, Canada
| | - J. Longstreth
- The Institute for Global Risk Research, Bethesda, MD, USA
| | - K. K. Pandey
- Institute of Wood Science and Technology, Bengaluru, India
| | - H. H. Redhwi
- Chemical Engineering Dept, King Fahd Univ. of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - A. Torikai
- Materials Life Society of Japan, Kayabacho Chuo-ku, Tokyo, Japan
| | - A. M. Heikkilä
- Finnish Meteorological Institute R&D/Climate Research, Helsinki, Finland
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8
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Molinier J. Genome and Epigenome Surveillance Processes Underlying UV Exposure in Plants. Genes (Basel) 2017; 8:genes8110316. [PMID: 29120372 PMCID: PMC5704229 DOI: 10.3390/genes8110316] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/03/2017] [Accepted: 11/03/2017] [Indexed: 02/07/2023] Open
Abstract
Land plants and other photosynthetic organisms (algae, bacteria) use the beneficial effect of sunlight as a source of energy for the photosynthesis and as a major source of information from the environment. However, the ultraviolet component of sunlight also produces several types of damage, which can affect cellular and integrity, interfering with growth and development. In order to reduce the deleterious effects of UV, photosynthetic organisms combine physiological adaptation and several types of DNA repair pathways to avoid dramatic changes in the structure. Therefore, plants may have obtained an evolutionary benefit from combining genome and surveillance processes, to efficiently deal with the deleterious effects of UV radiation. This review will present the different mechanisms activated upon UV exposure that contribute to maintain genome and integrity.
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Affiliation(s)
- Jean Molinier
- Institut de Biologie Moléculaire des Plantes, UPR2357-CNRS, 12 rue du Général Zimmer, 67000 Strasbourg, France.
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9
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Barnes PW, Ryel RJ, Flint SD. UV Screening in Native and Non-native Plant Species in the Tropical Alpine: Implications for Climate Change-Driven Migration of Species to Higher Elevations. FRONTIERS IN PLANT SCIENCE 2017; 8:1451. [PMID: 28878792 PMCID: PMC5572244 DOI: 10.3389/fpls.2017.01451] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 08/04/2017] [Indexed: 05/20/2023]
Abstract
Ongoing changes in Earth's climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280-315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (TUV A) in a diversity of plant species representing different growth forms to test whether native and non-native species growing above 2800 m elevation on Mauna Kea, Hawaii differed in their UV screening capabilities. We further compared the degree to which TUV A varied along an elevation gradient in the native shrub Vaccinium reticulatum and the introduced forb Verbascum thapsus to evaluate whether these species differed in their abilities to adjust their levels of UV screening in response to elevation changes in UV-B. For plants growing in the Mauna Kea alpine/upper subalpine, we found that adaxial TUV A, measured with a UVA-PAM fluorometer, varied significantly among species but did not differ between native (mean = 6.0%; n = 8) and non-native (mean = 5.8%; n = 11) species. When data were pooled across native and non-native taxa, we also found no significant effect of growth form on TUV A, though woody plants (shrubs and trees) were represented solely by native species whereas herbaceous growth forms (grasses and forbs) were dominated by non-native species. Along an elevation gradient spanning 2600-3800 m, TUV A was variable (mean range = 6.0-11.2%) and strongly correlated with elevation and relative biologically effective UV-B in the exotic V. thapsus; however, TUV A was consistently low (3%) and did not vary with elevation in the native V. reticulatum. Results indicate that high levels of UV protection occur in both native and non-native species in this high UV-B tropical alpine environment, and that flexibility in UV screening is a mechanism employed by some, but not all species to cope with varying solar UV-B exposures along elevation gradients.
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Affiliation(s)
- Paul W. Barnes
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, New OrleansLA, United States
- *Correspondence: Paul W. Barnes,
| | - Ronald J. Ryel
- Department of Wildland Resources, Utah State University, LoganUT, United States
| | - Stephan D. Flint
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, MoscowID, United States
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