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Neugart S, Steininger V, Fernandes C, Martínez-Abaigar J, Núñez-Olivera E, Schreiner M, Strid Å, Viczián A, Albert A, Badenes-Pérez FR, Castagna A, Dáder B, Fereres A, Gaberscik A, Gulyás Á, Gwynn-Jones D, Nagy F, Jones A, Julkunen-Tiitto R, Konstantinova N, Lakkala K, Llorens L, Martínez-Lüscher J, Nybakken L, Olsen J, Pascual I, Ranieri A, Regier N, Robson M, Rosenqvist E, Santin M, Turunen M, Vandenbussche F, Verdaguer D, Winkler B, Witzel K, Grifoni D, Zipoli G, Hideg É, Jansen MAK, Hauser MT. A synchronized, large-scale field experiment using Arabidopsis thaliana reveals the significance of the UV-B photoreceptor UVR8 under natural conditions. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38881245 DOI: 10.1111/pce.15008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/03/2024] [Accepted: 06/06/2024] [Indexed: 06/18/2024]
Abstract
This study determines the functional role of the plant ultraviolet-B radiation (UV-B) photoreceptor, UV RESISTANCE LOCUS 8 (UVR8) under natural conditions using a large-scale 'synchronized-genetic-perturbation-field-experiment'. Laboratory experiments have demonstrated a role for UVR8 in UV-B responses but do not reflect the complexity of outdoor conditions where 'genotype × environment' interactions can mask laboratory-observed responses. Arabidopsis thaliana knockout mutant, uvr8-7, and the corresponding Wassilewskija wild type, were sown outdoors on the same date at 21 locations across Europe, ranging from 39°N to 67°N latitude. Growth and climatic data were monitored until bolting. At the onset of bolting, rosette size, dry weight, and phenolics and glucosinolates were quantified. The uvr8-7 mutant developed a larger rosette and contained less kaempferol glycosides, quercetin glycosides and hydroxycinnamic acid derivatives than the wild type across all locations, demonstrating a role for UVR8 under field conditions. UV effects on rosette size and kaempferol glycoside content were UVR8 dependent, but independent of latitude. In contrast, differences between wild type and uvr8-7 in total quercetin glycosides, and the quercetin-to-kaempferol ratio decreased with increasing latitude, that is, a more variable UV response. Thus, the large-scale synchronized approach applied demonstrates a location-dependent functional role of UVR8 under natural conditions.
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Affiliation(s)
- Susanne Neugart
- Division Quality and Sensory of Plant Products, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Viktoria Steininger
- Department of Applied Genetics & Cell Biology, University of Natural Resources & Life Sciences, Vienna, Austria
| | - Catarina Fernandes
- Department of Applied Genetics & Cell Biology, University of Natural Resources & Life Sciences, Vienna, Austria
| | | | | | - Monika Schreiner
- Leibniz Institute of Vegetable and Ornamental Crops, Großbeeren, Germany
| | - Åke Strid
- Department of Natural Sciences, School of Science and Technology, Örebro University, Örebro, Sweden
| | - András Viczián
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Andreas Albert
- Research Unit Environmental Simulation, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Antonella Castagna
- Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy
| | - Beatriz Dáder
- Department of Agricultural Production, ETSIAAB, Universidad Politécnica de Madrid, Madrid, Spain
| | - Alberto Fereres
- Institute of Agricultural Sciences, Spanish Council for Scientific Research, Madrid, Spain
| | - Alenka Gaberscik
- Department of Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Ágnes Gulyás
- Department of Climatology and Landscape Ecology, University of Szeged, Szeged, Hungary
| | - Dylan Gwynn-Jones
- Department of Life Sciences, Aberystwyth University, Aberystwyth, UK
| | - Ferenc Nagy
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Alan Jones
- Earthwatch Europe, Oxford, UK
- Scion, New Zealand Forest Research Institute, Rotorua, New Zealand
| | | | - Nataliia Konstantinova
- Department of Applied Genetics & Cell Biology, University of Natural Resources & Life Sciences, Vienna, Austria
| | - Kaisa Lakkala
- Finnish Meteorological Institute - Space and Earth Observation Centre, Sodankylä, Finland
| | - Laura Llorens
- Department of Environmental Sciences, University of Girona, Girona, Spain
| | - Johann Martínez-Lüscher
- Plant Stress Physiology group (Associated Unit to EEAD, CSIC), BIOMA Institute for Biodiversity and the Environment, University of Navarra, Pamplona, Spain
| | - Line Nybakken
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Jorunn Olsen
- Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Inmaculada Pascual
- Plant Stress Physiology group (Associated Unit to EEAD, CSIC), BIOMA Institute for Biodiversity and the Environment, University of Navarra, Pamplona, Spain
| | - Annamaria Ranieri
- Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy
| | - Nicole Regier
- Earth and Environment Sciences, Forel Institute, Geneva University, Geneva, Switzerland
| | - Matthew Robson
- Organismal & Evolutionary Biology (OEB), Viikki Plant Science Centre (ViPS), Faculty of Biological & Environmental Sciences, University of Helsinki, Helsinki, Finland
- National School of Forestry, University of Cumbria, Ambleside, UK
| | - Eva Rosenqvist
- Institute of Plant and Environmental Sciences, Crop Science, University of Copenhagen, Tåstrup, Denmark
| | - Marco Santin
- Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy
| | - Minna Turunen
- Arctic Centre, University of Lapland, Rovaniemi, Finland
| | | | - Dolors Verdaguer
- Department of Environmental Sciences, University of Girona, Girona, Spain
| | - Barbro Winkler
- Research Unit Environmental Simulation, Helmholtz Zentrum München, Neuherberg, Germany
| | - Katja Witzel
- Leibniz Institute of Vegetable and Ornamental Crops, Großbeeren, Germany
| | - Daniele Grifoni
- National Research Council, Institute of Bioeconomy, Sesto Fiorentino, Italy
- Laboratory of Monitoring and Environmental Modelling for the Sustainable Development (LaMMA Consortium), Sesto Fiorentino, Italy
| | - Gaetano Zipoli
- National Research Council Institute for Biometeorology, Sesto Fiorentino, Italy
| | - Éva Hideg
- Department of Plant Biology, Faculty of Sciences, University of Pécs, Pécs, Hungary
| | - Marcel A K Jansen
- Environmental Research Institute, School of Biological, Earth, and Environmental Sciences, University College Cork, Cork, Ireland
| | - Marie-Theres Hauser
- Department of Applied Genetics & Cell Biology, University of Natural Resources & Life Sciences, Vienna, Austria
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Ač A, Jansen MAK, Grace J, Urban O. Unravelling the neglected role of ultraviolet radiation on stomata: A meta-analysis with implications for modelling ecosystem-climate interactions. PLANT, CELL & ENVIRONMENT 2024; 47:1769-1781. [PMID: 38314642 DOI: 10.1111/pce.14841] [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: 11/03/2023] [Revised: 01/17/2024] [Accepted: 01/23/2024] [Indexed: 02/06/2024]
Abstract
Stomata play a pivotal role in regulating gas exchange between plants and the atmosphere controlling water and carbon cycles. Accordingly, we investigated the impact of ultraviolet-B radiation, a neglected environmental factor varying with ongoing global change, on stomatal morphology and function by a Comprehensive Meta-Analysis. The overall UV effect at the leaf level is to decrease stomatal conductance, stomatal aperture and stomatal size, although stomatal density was increased. The significant decline in stomatal conductance is marked (6% in trees and >10% in grasses and herbs) in short-term experiments, with more modest decreases noted in long-term UV studies. Short-term experiments in growth chambers are not representative of long-term field UV effects on stomatal conductance. Important consequences of altered stomatal function are hypothesized. In the short term, UV-mediated stomatal closure may reduce carbon uptake but also water loss through transpiration, thereby alleviating deleterious effects of drought. However, in the long term, complex changes in stomatal aperture, size, and density may reduce the carbon sequestration capacity of plants and increase vegetation and land surface temperatures, potentially exacerbating negative effects of drought and/or heatwaves. Therefore, the expected future strength of carbon sink capacity in high-UV regions is likely overestimated.
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Affiliation(s)
- Alexander Ač
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
| | - Marcel A K Jansen
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
- School of Biological, Earth and Environmental Sciences, Environmental Research Institute, UCC, Cork, Ireland
| | - John Grace
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Otmar Urban
- Global Change Research of the Czech Academy of Sciences, Brno, Czech Republic
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Hird C, Cramp RL, Franklin CE. Thermal compensation reduces DNA damage from UV radiation. J Therm Biol 2023; 117:103711. [PMID: 37717403 DOI: 10.1016/j.jtherbio.2023.103711] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/19/2023]
Abstract
Increases in ultraviolet radiation (UVR) correlate spatially and temporally with global amphibian population declines and interact with other stressors such as disease and temperature. Declines have largely occurred in high-altitude areas associated with greater UVR and cooler temperatures. UVR is a powerful mutagenic harming organisms largely by damaging DNA. When acutely exposed to UVR at cool temperatures, amphibian larvae have increased levels of DNA damage. Amphibians may compensate for the depressive effects of temperature on DNA damage through acclimatisation, but it is unknown whether they have this capacity. We reared striped marsh frog larvae (Limnodynastes peronii) in warm (25 °C) and cool (15 °C) temperatures under a low or moderate daily dose of UVR (10 and 40 μW cm-2 UV-B for 1 h at midday, respectively) for 18-20 days and then measured DNA damage resulting from an acute high UVR dose (80 μW cm-2 UV-B for 1.5 h) at a range of temperatures (10, 15, 20, 25, and 30 °C). Larvae acclimated to 15 °C and exposed to UVR at 15 °C completely compensated UVR-induced DNA damage compared with 25 °C acclimated larvae exposed to UVR at 25 °C. Additionally, warm-acclimated larvae had higher DNA damage than cold-acclimated larvae across test temperatures, which indicated a cost of living in warmer temperatures. Larvae reared under elevated UVR levels showed no evidence of UVR acclimation resulting in lower DNA damage following high UVR exposure. Our finding that thermal acclimation in L. peronii larvae compensated UVR-induced DNA damage at low temperatures suggested that aquatic ectotherms living in cool temperatures may be more resilient to high UVR than previously realised. We suggested individuals or species with less capacity for thermal acclimation of DNA repair mechanisms may be more at risk if exposed to changing thermal and UVR exposure regimes.
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Affiliation(s)
- Coen Hird
- School of the Environment, The University of Queensland, Magandjin, 4072, Australia.
| | - Rebecca L Cramp
- School of the Environment, The University of Queensland, Magandjin, 4072, Australia
| | - Craig E Franklin
- School of the Environment, The University of Queensland, Magandjin, 4072, Australia
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Uyeki SC, Pacheco CM, Simeral ML, Hafner JH. The Raman Active Vibrations of Flavone and Quercetin: The Impact of Conformers and Hydrogen Bonding on Fingerprint Modes. J Phys Chem A 2023; 127:1387-1394. [PMID: 36735995 DOI: 10.1021/acs.jpca.2c06718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The detection and analysis of flavonoids by Raman spectroscopy are of interest in many fields, including medicinal chemistry, food science, and astrobiology. Spectral interpretation would benefit from better identification of the fingerprint vibrational peaks of different flavonoids and how they are affected by intermolecular interactions. The Raman spectra of two flavonoids, flavone and quercetin, were investigated through comparisons between spectra recorded from pure powders and spectra calculated with time dependent density functional theory (TDDFT). For both flavone and quercetin, 17 peaks were assigned to specific molecular vibrations. Both flavonoids were found to have a split peak between 1250-1350 cm-1 that is not predicted by TDDFT calculations on isolated molecules. In each case, it is shown that the addition of hydrogen bonded molecules arranged based on crystal structures reproduces the split peaks. These peaks were due to a stretching vibration of the bond between benzopyrone and phenyl rings and represent a characteristic spectral feature of flavonoids. Spectra of pollen grains from Quercus virginiana were also recorded and exhibit several peaks that correspond to the quercetin spectrum.
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Affiliation(s)
- S Campbell Uyeki
- Department of Physics & Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Charles M Pacheco
- Department of Physics & Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Mathieu L Simeral
- Department of Physics & Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Jason H Hafner
- Department of Physics & Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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Mohanty SR, Mahawar H, Bajpai A, Dubey G, Parmar R, Atoliya N, Devi MH, Singh AB, Jain D, Patra A, Kollah B. Methylotroph bacteria and cellular metabolite carotenoid alleviate ultraviolet radiation-driven abiotic stress in plants. Front Microbiol 2023; 13:899268. [PMID: 36687662 PMCID: PMC9853530 DOI: 10.3389/fmicb.2022.899268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 09/30/2022] [Indexed: 01/07/2023] Open
Abstract
Increasing UV radiation in the atmosphere due to the depletion of ozone layer is emerging abiotic stress for agriculture. Although plants have evolved to adapt to UV radiation through different mechanisms, but the role of phyllosphere microorganisms in counteracting UV radiation is not well studied. The current experiment was undertaken to evaluate the role of phyllosphere Methylobacteria and its metabolite in the alleviation of abiotic stress rendered by ultraviolet (UV) radiation. A potential pink pigmenting methylotroph bacterium was isolated from the phylloplane of the rice plant (oryzae sativa). The 16S rRNA gene sequence of the bacterium was homologous to the Methylobacter sp. The isolate referred to as Methylobacter sp N39, produced beta-carotene at a rate (μg ml-1 d-1) of 0.45-3.09. Biosynthesis of beta-carotene was stimulated by brief exposure to UV for 10 min per 2 days. Carotenoid biosynthesis was predicted as y = 3.09 × incubation period + 22.151 (r 2 = 0.90). The carotenoid extract of N39 protected E. coli from UV radiation by declining its death rate from 14.67% min-1 to 4.30% min-1 under UV radiation. Application of N39 cells and carotenoid extract also protected rhizobium (Bradyrhizobium japonicum) cells from UV radiation. Scanning electron microscopy indicated that the carotenoid extracts protected E. coli cells from UV radiation. Foliar application of either N39 cells or carotenoid extract enhanced the plant's (Pigeon pea) resistance to UV irradiation. This study highlight that Methylobacter sp N39 and its carotenoid extract can be explored to manage UV radiation stress in agriculture.
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Affiliation(s)
- Santosh Ranjan Mohanty
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India,*Correspondence: Santosh Ranjan Mohanty, ,
| | - Himanshu Mahawar
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India,ICAR -s Directorate of Weed Research, Jabalpur, Madhya Pradesh, India,Himanshu Mahawar,
| | - Apekcha Bajpai
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Garima Dubey
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Rakesh Parmar
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Nagvanti Atoliya
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | | | | | - Devendra Jain
- Department of Molecular Biology and Biotechnology, Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India
| | - Ashok Patra
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Bharati Kollah
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India,Bharati Kollah, ,
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Alchemilla monticola Opiz. Functional Traits Respond to Diverse Alpine Environmental Conditions in Karavanke, Slovenia. PLANTS 2022; 11:plants11192527. [PMID: 36235393 PMCID: PMC9571203 DOI: 10.3390/plants11192527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/19/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022]
Abstract
Alpine plants are exposed to demanding environmental conditions, such as high ultraviolet (UV) and photosynthetic radiation, extreme temperatures, drought, and nutrient deficiencies. Alpine plants adapt and acclimate to harsh conditions, developing several strategies, including biochemical, physiological, and optical responses. However, alpine plants’ survival strategies are hardly researched due to time-consuming and complex experimental conditions, which are supported by scarce studies. Our study focused on the functional traits of the alpine plant Alchemilla monticola Opiz (hairy lady’s mantle) growing at two different altitudes (1500, 2000 m a.s.l.) and two different UV exposures per altitude. Near-ambient (UV) and reduced (UV-) UV radiations were provided by using two sorts of UV absorbing filters; temperatures were monitored hourly. The experimental plots were located at Tegoška Gora, Karavanke, Slovenia. Functional traits: physiological, biochemical, and optical characteristics were recorded three times during the growing season. A. monticola showed high maximum photochemical efficiency at both altitudes throughout the season, which confirms good adaptation and acclimatization of the plant. Furthermore, significantly higher maximum photochemical efficiency at the subalpine altitude coincided with significantly higher UV absorbing compounds (UV AC) contents at the subalpine compared to the montane altitude in August. A. monticola manifested high UV AC contents throughout the season, with significantly increased synthesis of UV AC contents in the subalpine conditions in August and September. The stomatal conductance rate increased with altitude and was correlated mostly to a lower temperature. A. monticola leaves did not transmit any UV spectrum, which corresponded to high total UV AC contents. The leaf transmittance of the photosynthetic spectrum increased at the subalpine altitude, while the transmittance of the green and yellow spectra increased under the reduced UV radiation in the autumn. A. monticola’s high photosynthetic spectrum transmittance at the subalpine altitude in the autumn might therefore be due to subalpine harsh environmental conditions, as well as plant ontogenetical phase.
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Nichelmann L, Pescheck F. Solar UV-B effects on composition and UV screening efficiency of foliar phenolics in Arabidopsis thaliana are augmented by temperature. PHYSIOLOGIA PLANTARUM 2021; 173:762-774. [PMID: 34510467 DOI: 10.1111/ppl.13554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/25/2021] [Accepted: 09/06/2021] [Indexed: 05/24/2023]
Abstract
The accumulation of foliar phenolics constitutes one strategy of plants against the potentially harmful effects of ultraviolet-B and A (UV-B, UV-A) radiation. These compounds protect photosensitive tissues by shielding and antioxidative function. It is unknown, however, whether seasonal acclimation to natural conditions may modify the UV-B effect on phenylpropanoid composition and localisation, and thus their screening efficiency. To address this debate, a field experiment with the wildtype of Arabidopsis thaliana accession Landsberg erecta (Ler) was implemented over a whole year with plants exposed to different UV-filter treatments. While seasonal increases of UV-B radiation had a slight negative effect on the amount of hydroxycinnamic acids (HCAs), low temperatures increased foliar HCAs. HCAs, however, did not contribute substantially to seasonal changes of in vivo UV absorbance. Kaempferol and quercetin derivatives increased significantly under ambient UV-B radiation, and low temperature interacted with this effect. A shift of epidermal UV-A shielding from kaempferol to quercetin derivatives was elucidated in UV-B presence. Despite this, a substantial 20-fold increase of quercetin derivatives, during periods with high irradiance and low temperature, did not affect UV absorbance leading to the conclusion that quercetin accumulation was not exclusively in epidermal vacuoles. Using confocal microscopy, the potential occurrence of quercetin in mesophyll cells was demonstrated in plants grown with experimental UV-B radiation at low temperature for the first time in A. thaliana. The presented study discusses the idea that cross-talk of UV-B radiation and temperature might adjust the physiological function of quercetin from an (epidermal) screening to an antioxidant substance.
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Affiliation(s)
- Lars Nichelmann
- Botanical Institute and Botanical Garden, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Frauke Pescheck
- Botanical Institute and Botanical Garden, Christian-Albrechts-University of Kiel, Kiel, Germany
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Neugart S, Tobler MA, Barnes PW. Rapid adjustment in epidermal UV sunscreen: Comparison of optical measurement techniques and response to changing solar UV radiation conditions. PHYSIOLOGIA PLANTARUM 2021; 173:725-735. [PMID: 34375003 DOI: 10.1111/ppl.13517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 06/02/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
The accumulation of soluble and cell-wall bound UV-absorbing compounds (i.e., flavonoids) in the epidermis and the mesophyll of leaves is a response of plants to UV exposure. These compounds are known to function in UV screening, but they are also of potential value for food quality. One way to non-destructively monitor UV screening in leaves is by optical methods, from which UVA-PAM and Dualex instruments stand out. The degree and rapidity to which plants can modulate UV screening in response to fluctuating solar UV conditions is poorly understood. In this study, okra plants were exposed to two solar radiation treatments (near-ambient UV [+UV] and attenuated UV [-UV]) and the epidermal UV transmittance (TUV ; UVA-PAM) and flavonoid index (Dualex) were measured in the youngest and second youngest mature leaves over three consecutive days and within an individual day. The day-to-day (measured near solar noon) and diurnal (over the course of a day) measurements of leaf optical properties indicated that TUV decreased and flavonoid index increased in the adaxial epidermis ~50% until 15:00 CDT then returned close to morning values later in the day. Correlations between UV-B radiation and TUV and flavonoid index revealed highest values 30 min to 1 h prior to the measurements. These findings indicate that plants can respond quickly to fluctuating solar UV conditions and underlines the importance of the harvest-time point for health-promoting compounds in fruit and vegetables. Our findings also indicate that the UVA-PAM and the Dualex instruments are both suitable instruments to monitor rapid changes in UV screening in plants.
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Affiliation(s)
- Susanne Neugart
- Division Quality and Sensory of Plant Products, Georg-August-Universität Göttingen, Goettingen, Germany
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, New Orleans, Louisiana
| | - Mark A Tobler
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, New Orleans, Louisiana
| | - Paul W Barnes
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, New Orleans, Louisiana
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Neugart S, Tobler MA, Barnes PW. The Function of Flavonoids in the Diurnal Rhythm under Rapidly Changing UV Conditions—A Model Study on Okra. PLANTS 2021; 10:plants10112268. [PMID: 34834632 PMCID: PMC8624821 DOI: 10.3390/plants10112268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/18/2022]
Abstract
Flavonoids are favored compounds in plant responses to UV exposure and act in UV absorption and antioxidant activity. Here, it was investigated, with okra as a model species, how fast plants can react to changing UV conditions and to what extent these reactions take place. Okra (Abelmoschus esculentus) plants were exposed to either full or nearly no UV radiation. The diurnal rhythm of the plants was driven by the UV radiation and showed up to a 50% increase of the flavonoid content (measured optically in the +UV plants). This was reflected only in the trends in UV-absorption and antioxidant activity of the extracts but not in the soluble flavonoid glycosides and hydroxycinnamic acid derivatives. In a second experiment, a transfer from a −UV to a +UV condition at 9:00 CDT showed the immediate start of the diurnal rhythm, while this did not occur if the transfer occurred later in the day; these plants only started a diurnal rhythm the following day. After an adaptation period of seven days, clear differences between the +UV and -UV plants could be found in all parameters, whereas plants transferred to the opposite UV condition settle between the +UV and -UV plants in all parameters. Broadly, it can be seen that the flavonoid contents and associated functions in the plant are subject to considerable changes within one day and within several days due to the UV conditions and that this can have a considerable impact on the quality of plant foods.
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Affiliation(s)
- Susanne Neugart
- Division Quality and Sensory of Plant Products, Georg-August-Universität Göttingen, 37075 Goettingen, Germany
- Department of Biological Sciences, Loyola University New Orleans, 6363 St. Charles Avenue, New Orleans, LA 70118, USA; (M.A.T.); (P.W.B.)
- Correspondence: ; Tel.: +49-551-3927958
| | - Mark A. Tobler
- Department of Biological Sciences, Loyola University New Orleans, 6363 St. Charles Avenue, New Orleans, LA 70118, USA; (M.A.T.); (P.W.B.)
| | - Paul W. Barnes
- Department of Biological Sciences, Loyola University New Orleans, 6363 St. Charles Avenue, New Orleans, LA 70118, USA; (M.A.T.); (P.W.B.)
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Stiller A, Garrison K, Gurdyumov K, Kenner J, Yasmin F, Yates P, Song BH. From Fighting Critters to Saving Lives: Polyphenols in Plant Defense and Human Health. Int J Mol Sci 2021; 22:8995. [PMID: 34445697 PMCID: PMC8396434 DOI: 10.3390/ijms22168995] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 02/08/2023] Open
Abstract
Polyphenols, such as flavonoids and phenolic acids, are a group of specialized metabolites in plants that largely aid in plant defense by deterring biotic stressors and alleviating abiotic stress. Polyphenols offer a wide range of medical applications, acting as preventative and active treatments for diseases such as cancers and diabetes. Recently, researchers have proposed that polyphenols may contribute to certain applications aimed at tackling challenges related to the COVID-19 pandemic. Understanding the beneficial impacts of phytochemicals, such as polyphenols, could potentially help prepare society for future pandemics. Thus far, most reviews have focused on polyphenols in cancer prevention and treatment. This review aims to provide a comprehensive discussion on the critical roles that polyphenols play in both plant chemical defense and human health based on the most recent studies while highlighting prospective avenues for future research, as well as the implications for phytochemical-based applications in both agricultural and medical fields.
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Affiliation(s)
| | | | | | | | | | | | - Bao-Hua Song
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; (A.S.); (K.G.); (K.G.); (J.K.); (F.Y.); (P.Y.)
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Karabourniotis G, Liakopoulos G, Bresta P, Nikolopoulos D. The Optical Properties of Leaf Structural Elements and Their Contribution to Photosynthetic Performance and Photoprotection. PLANTS (BASEL, SWITZERLAND) 2021; 10:1455. [PMID: 34371656 PMCID: PMC8309337 DOI: 10.3390/plants10071455] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 12/18/2022]
Abstract
Leaves have evolved to effectively harvest light, and, in parallel, to balance photosynthetic CO2 assimilation with water losses. At times, leaves must operate under light limiting conditions while at other instances (temporally distant or even within seconds), the same leaves must modulate light capture to avoid photoinhibition and achieve a uniform internal light gradient. The light-harvesting capacity and the photosynthetic performance of a given leaf are both determined by the organization and the properties of its structural elements, with some of these having evolved as adaptations to stressful environments. In this respect, the present review focuses on the optical roles of particular leaf structural elements (the light capture module) while integrating their involvement in other important functional modules. Superficial leaf tissues (epidermis including cuticle) and structures (epidermal appendages such as trichomes) play a crucial role against light interception. The epidermis, together with the cuticle, behaves as a reflector, as a selective UV filter and, in some cases, each epidermal cell acts as a lens focusing light to the interior. Non glandular trichomes reflect a considerable part of the solar radiation and absorb mainly in the UV spectral band. Mesophyll photosynthetic tissues and biominerals are involved in the efficient propagation of light within the mesophyll. Bundle sheath extensions and sclereids transfer light to internal layers of the mesophyll, particularly important in thick and compact leaves or in leaves with a flutter habit. All of the aforementioned structural elements have been typically optimized during evolution for multiple functions, thus offering adaptive advantages in challenging environments. Hence, each particular leaf design incorporates suitable optical traits advantageously and cost-effectively with the other fundamental functions of the leaf.
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Affiliation(s)
- George Karabourniotis
- Laboratory of Plant Physiology and Morphology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece; (G.L.); (D.N.)
| | - Georgios Liakopoulos
- Laboratory of Plant Physiology and Morphology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece; (G.L.); (D.N.)
| | - Panagiota Bresta
- Laboratory of Electron Microscopy, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece;
| | - Dimosthenis Nikolopoulos
- Laboratory of Plant Physiology and Morphology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece; (G.L.); (D.N.)
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12
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Mariz-Ponte N, Mendes RJ, Sario S, Correia CV, Correia CM, Moutinho-Pereira J, Melo P, Dias MC, Santos C. Physiological, Biochemical and Molecular Assessment of UV-A and UV-B Supplementation in Solanum lycopersicum. PLANTS 2021; 10:plants10050918. [PMID: 34063679 PMCID: PMC8147646 DOI: 10.3390/plants10050918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/16/2022]
Abstract
Daily UV-supplementation during the plant fruiting stage of tomato (Solanum lycopersicum L.) growing indoors may produce fruits with higher nutraceutical value and better acceptance by consumers. However, it is important to ensure that the plant's performance during this stage is not compromised by the UV supplement. We studied the impact of UV-A (1 and 4 h) and UV-B (2 and 5 min) on the photosynthesis of greenhouse-grown tomato plants during the fruiting/ripening stage. After 30 d of daily irradiation, UV-B and UV-A differently interfered with the photosynthesis. UV-B induced few leaf-necrotic spots, and effects are more evidenced in the stimulation of photosynthetic/protective pigments, meaning a structural effect at the Light-Harvesting Complex. UV-A stimulated flowering/fruiting, paralleled with no visible leaf damages, and the impact on photosynthesis was mostly related to functional changes, in a dose-dependent manner. Both UV-A doses decreased the maximum quantum efficiency of photosystem II (Fv/Fm), the effective efficiency of photosystem II (ΦPSII), and gas exchange processes, including net carbon assimilation (PN). Transcripts related to Photosystem II (PSII) and RuBisCO were highly stimulated by UV supplementation (mostly UV-A), but the maintenance of the RuBisCO protein levels indicates that some protein is also degraded. Our data suggest that plants supplemented with UV-A activate adaptative mechanisms (including increased transcription of PSII peptides and RuBisCO), and any negative impacts on photosynthesis do not compromise the final carbohydrate balances and plant yield, thus becoming a profitable tool to improve precision agriculture.
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Affiliation(s)
- Nuno Mariz-Ponte
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; (R.J.M.); (S.S.); (C.V.C.); (P.M.); (C.S.)
- LAQV-REQUIMTE, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
- Correspondence:
| | - Rafael J. Mendes
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; (R.J.M.); (S.S.); (C.V.C.); (P.M.); (C.S.)
- LAQV-REQUIMTE, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Sara Sario
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; (R.J.M.); (S.S.); (C.V.C.); (P.M.); (C.S.)
- LAQV-REQUIMTE, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Cristiana V. Correia
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; (R.J.M.); (S.S.); (C.V.C.); (P.M.); (C.S.)
- LAQV-REQUIMTE, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Carlos M. Correia
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), Department of Biology and Environment, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal; (C.M.C.); (J.M.-P.)
| | - José Moutinho-Pereira
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), Department of Biology and Environment, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal; (C.M.C.); (J.M.-P.)
| | - Paula Melo
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; (R.J.M.); (S.S.); (C.V.C.); (P.M.); (C.S.)
| | - Maria Celeste Dias
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal;
| | - Conceição Santos
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; (R.J.M.); (S.S.); (C.V.C.); (P.M.); (C.S.)
- LAQV-REQUIMTE, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
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13
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Xiong F, Nie X, Yang L, Wang L, Li J, Zhou G. Non-target metabolomics revealed the differences between Rh. tanguticum plants growing under canopy and open habitats. BMC PLANT BIOLOGY 2021; 21:119. [PMID: 33639841 PMCID: PMC7913229 DOI: 10.1186/s12870-021-02897-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 02/21/2021] [Indexed: 05/28/2023]
Abstract
BACKGROUND Rheum tanguticum (Rh. tanguticum) is an important traditional Chinese medicine plant, "Dahuang", which contains productive metabolites and occupies wide habitats on the Qinghai-Tibet plateau. Plants occupying wide habitats usually vary in phenotypes such as in morphology and metabolism, thereby developing into different ecotypes. Under canopy and open habitats are a pair of dissimilar habitats which possess Rh. tanguticum plants. However, few studies have focused on the effect of habitats on Rh. tanguticum growth, particularly combining morphological and metabolic changes. This study focused on Rh. tanguticum plants growing in under canopy and open habitats where morphology and metabolism changes were quantified using non-target metabolism methods. RESULTS The obtained results indicated that the two dissimilar habitats led to Rh. tanguticum developing into two distinct ecotypes where the morphology and metabolism were simultaneously changed. Under canopy habitats bred morphologically smaller Rh. tanguticum plants which had a higher level of metabolites (22 out of 31) which included five flavonoids, four isoflavonoids, and three anthracenes. On the other hand, the open habitats produced morphologically larger Rh. tanguticum plants having a higher level of metabolites (9 out of 31) including four flavonoids. 6 of the 31 metabolites were predicted to have effect targets, include 4 represent for under canopy habitats and 2 for open habitats. Totally, 208 targets were connected, among which 42 were communal targets for both under canopy and open habitats represent compounds, and 100 and 66 were unique targets for under canopy superior compounds and open habitats superior compounds, respectively. In addition, aloe-emodin, emodin, chrysophanol, physcion, sennoside A and sennoside B were all more accumulated in under canopy habitats, and among which aloe-emodin, emodin, chrysophanol and physcion were significantly higher in under canopy habitats. CONCLUSIONS This study determined that Rh. tanguticum growing in under canopy and in open habitats developed into two distinct ecotypes with morphological and metabolic differences. Results of network pharmacology study has indicated that "Dahuang" coming from different habitats, such as under canopy and open habitats, are different in effect targets and thus may have different medicinal use. According to target metabolomics, under canopy habitats may grow better "Dahuang".
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Affiliation(s)
- Feng Xiong
- CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, 810008, China
- College of Resources and Environment, University of Chinese Academy of Science, Beijing, 100049, China
| | - Xiuqing Nie
- Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry Chinese Academy of Forestry, Beijing, 100091, China
- Research Institute of Nature Protected Area Chinese Academy of Forestry, Beijing, 100091, China
| | - Lucun Yang
- CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, 810008, China
| | - Lingling Wang
- CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, 810008, China
- College of Resources and Environment, University of Chinese Academy of Science, Beijing, 100049, China
| | - Jingjing Li
- College of Life Sciences, Qinghai Normal University, Xining, 810008, China
| | - Guoying Zhou
- CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, 810008, China.
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14
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Fernández-Marín B, Gulías J, Figueroa CM, Iñiguez C, Clemente-Moreno MJ, Nunes-Nesi A, Fernie AR, Cavieres LA, Bravo LA, García-Plazaola JI, Gago J. How do vascular plants perform photosynthesis in extreme environments? An integrative ecophysiological and biochemical story. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:979-1000. [PMID: 31953876 DOI: 10.1111/tpj.14694] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 12/14/2019] [Accepted: 01/07/2020] [Indexed: 05/24/2023]
Abstract
In this work, we review the physiological and molecular mechanisms that allow vascular plants to perform photosynthesis in extreme environments, such as deserts, polar and alpine ecosystems. Specifically, we discuss the morpho/anatomical, photochemical and metabolic adaptive processes that enable a positive carbon balance in photosynthetic tissues under extreme temperatures and/or severe water-limiting conditions in C3 species. Nevertheless, only a few studies have described the in situ functioning of photoprotection in plants from extreme environments, given the intrinsic difficulties of fieldwork in remote places. However, they cover a substantial geographical and functional range, which allowed us to describe some general trends. In general, photoprotection relies on the same mechanisms as those operating in the remaining plant species, ranging from enhanced morphological photoprotection to increased scavenging of oxidative products such as reactive oxygen species. Much less information is available about the main physiological and biochemical drivers of photosynthesis: stomatal conductance (gs ), mesophyll conductance (gm ) and carbon fixation, mostly driven by RuBisCO carboxylation. Extreme environments shape adaptations in structures, such as cell wall and membrane composition, the concentration and activation state of Calvin-Benson cycle enzymes, and RuBisCO evolution, optimizing kinetic traits to ensure functionality. Altogether, these species display a combination of rearrangements, from the whole-plant level to the molecular scale, to sustain a positive carbon balance in some of the most hostile environments on Earth.
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Affiliation(s)
- Beatriz Fernández-Marín
- Department of Botany, Ecology and Plant Physiology, University of La Laguna, Tenerife, 38200, Spain
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Javier Gulías
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB), Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Ctra. Valldemossa km 7.5, 07122, Palma, Spain
| | - Carlos M Figueroa
- UNL, CONICET, FBCB, Instituto de Agrobiotecnología del Litoral, 3000, Santa Fe, Argentina
| | - Concepción Iñiguez
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB), Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Ctra. Valldemossa km 7.5, 07122, Palma, Spain
| | - María J Clemente-Moreno
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB), Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Ctra. Valldemossa km 7.5, 07122, Palma, Spain
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil
| | - Alisdair R Fernie
- Central Metabolism Group, Molecular Physiology Department, Max-Planck-Institut für Molekulare Pflanzenphysiologie, Golm, Germany
| | - Lohengrin A Cavieres
- ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - León A Bravo
- Lab. de Fisiología y Biología Molecular Vegetal, Dpt. de Cs. Agronómicas y Recursos Naturales, Facultad de Cs. Agropecuarias y Forestales, Instituto de Agroindustria, Universidad de La Frontera, Temuco, Chile
- Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Temuco, Chile
| | - José I García-Plazaola
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Jorge Gago
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB), Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Ctra. Valldemossa km 7.5, 07122, Palma, Spain
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15
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Robson TM, Aphalo PJ, Banaś AK, Barnes PW, Brelsford CC, Jenkins GI, Kotilainen TK, Łabuz J, Martínez-Abaigar J, Morales LO, Neugart S, Pieristè M, Rai N, Vandenbussche F, Jansen MAK. A perspective on ecologically relevant plant-UV research and its practical application. Photochem Photobiol Sci 2019; 18:970-988. [PMID: 30720036 DOI: 10.1039/c8pp00526e] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Plants perceive ultraviolet-B (UV-B) radiation through the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8), and initiate regulatory responses via associated signalling networks, gene expression and metabolic pathways. Various regulatory adaptations to UV-B radiation enable plants to harvest information about fluctuations in UV-B irradiance and spectral composition in natural environments, and to defend themselves against UV-B exposure. Given that UVR8 is present across plant organs and tissues, knowledge of the systemic signalling involved in its activation and function throughout the plant is important for understanding the context of specific responses. Fine-scale understanding of both UV-B irradiance and perception within tissues and cells requires improved application of knowledge about UV-attenuation in leaves and canopies, warranting greater consideration when designing experiments. In this context, reciprocal crosstalk among photoreceptor-induced pathways also needs to be considered, as this appears to produce particularly complex patterns of physiological and morphological response. Through crosstalk, plant responses to UV-B radiation go beyond simply UV-protection or amelioration of damage, but may give cross-protection over a suite of environmental stressors. Overall, there is emerging knowledge showing how information captured by UVR8 is used to regulate molecular and physiological processes, although understanding of upscaling to higher levels of organisation, i.e. organisms, canopies and communities remains poor. Achieving this will require further studies using model plant species beyond Arabidopsis, and that represent a broad range of functional types. More attention should also be given to plants in natural environments in all their complexity, as such studies are needed to acquire an improved understanding of the impact of climate change in the context of plant-UV responses. Furthermore, broadening the scope of experiments into the regulation of plant-UV responses will facilitate the application of UV radiation in commercial plant production. By considering the progress made in plant-UV research, this perspective highlights prescient topics in plant-UV photobiology where future research efforts can profitably be focussed. This perspective also emphasises burgeoning interdisciplinary links that will assist in understanding of UV-B effects across organisational scales and gaps in knowledge that need to be filled so as to achieve an integrated vision of plant responses to UV-radiation.
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Affiliation(s)
- T Matthew Robson
- Organismal and Evolutionary Biology, Viikki Plant Science Centre (ViPS), University of Helsinki, Finland.
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16
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Vanhaelewyn L, Bernula P, Van Der Straeten D, Vandenbussche F, Viczián A. UVR8-dependent reporters reveal spatial characteristics of signal spreading in plant tissues. Photochem Photobiol Sci 2019; 18:1030-1045. [PMID: 30838366 DOI: 10.1039/c8pp00492g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The UV Resistance Locus 8 (UVR8) photoreceptor controls UV-B mediated photomorphogenesis in Arabidopsis. The aim of this work is to collect and characterize different molecular reporters of photomorphogenic UV-B responses. Browsing available transcriptome databases, we identified sets of genes responding specifically to this radiation and are controlled by pathways initiated from the UVR8 photoreceptor. We tested the transcriptional changes of several reporters and found that they are regulated differently in different parts of the plant. Our experimental system led us to conclude that the examined genes are not controlled by light piping of UV-B from the shoot to the root or signalling molecules which may travel between different parts of the plant body but by local UVR8 signalling. The initiation of these universal signalling steps can be the induction of Elongated Hypocotyl 5 (HY5) and its homologue, HYH transcription factors. We found that their transcript and protein accumulation strictly depends on UVR8 and happens in a tissue autonomous manner. Whereas HY5 accumulation correlates well with the UVR8 signal across cell layers, the induction of flavonoids depends on both UVR8 signal and a yet to be identified tissue-dependent or developmental determinant.
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Affiliation(s)
- Lucas Vanhaelewyn
- Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, KL Ledeganckstraat 35, B-9000 Gent, Belgium
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17
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Csepregi K, Teszlák P, Kőrösi L, Hideg É. Changes in grapevine leaf phenolic profiles during the day are temperature rather than irradiance driven. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 137:169-178. [PMID: 30797184 DOI: 10.1016/j.plaphy.2019.02.012] [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: 11/28/2018] [Revised: 02/07/2019] [Accepted: 02/13/2019] [Indexed: 05/22/2023]
Abstract
Photosynthesis parameters, adaxial flavonoid index, phenolic profiles and antioxidant capacities of south-facing sun exposed grapevine leaves (Vitis vinifera, Pinot Noir cultivar) were measured hourly between 7 a.m. and 7 p.m. on a clear summer day. Changes in these parameters were statistically compared to changes in environmental conditions, including solar irradiance (photosynthetically active and UV radiations), leaf and air temperature, and relative air humidity. Epidermal UV absorbance, characterised by the flavonoid index, and total extractable phenolic contents were correlated to distinct environmental parameters. The former was positively correlated to irradiance and leaf temperature, while the latter was positively correlated to air temperature. HPLC phenolic profiling identified a positive correlation between air temperature and amounts of the dominant flavonol component, quercetin-3-O-glucuronide. The only phenolic component statistically connected to the flavonoid index was quercetin-3-O-glucoside. This correlation was positive and both parameters decreased during the day, although changes in the amount of this flavonol component showed no correlation to environmental factors. Total antioxidant capacities of leaf extracts were positively correlated to solar UV, and leaf and air temperature, but not to photosynthetically active radiation. Positive correlations of quercetin-3-O-glucoside contents with the flavonoid index, with photosynthesis and with sub-stomatal CO2 concentration suggest a special protective role of this flavonol. A short-term negative effect of solar UV-A and UV-B on photosynthetic CO2 uptake was also identified, which was unrelated to changes in stomatal conductance. A hypothesis is presented assuming UV- and photorespiration-derived hydrogen peroxide as the driver of daily changes in leaf antioxidant capacities.
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Affiliation(s)
| | - Péter Teszlák
- Research Institute for Viticulture and Oenology, University of Pécs, Pécs, Hungary
| | - László Kőrösi
- Research Institute for Viticulture and Oenology, University of Pécs, Pécs, Hungary
| | - Éva Hideg
- Department of Plant Biology, University of Pécs, Pécs, Hungary.
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18
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Schultze M, Bilger W. Acclimation of Arabidopsis thaliana to low temperature protects against damage of photosystem II caused by exposure to UV-B radiation at 9 °C. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 134:73-80. [PMID: 30366738 DOI: 10.1016/j.plaphy.2018.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 10/12/2018] [Accepted: 10/12/2018] [Indexed: 06/08/2023]
Abstract
Various environmental variables interact with UV-B radiation (280-315 nm), among them temperature. In many plants epidermal UV screening is induced by low temperature even in the absence of UV irradiation. On the other hand, low temperature can aggravate damage caused by UV-B radiation. We investigated the interaction of UV-B radiation and low temperature in Arabidopsis thaliana (L.) Heynh. Exposure of plants grown at moderate temperature (21 °C) to UV-B radiation at 9 °C resulted in significantly higher damage of photosystem II (PS II) as compared to exposure at 21 °C. The higher damage at low temperature was related to slower recovery of maximal PS II quantum efficiency at this temperature. Epidermal UV-B transmittance was measured using a method based on chlorophyll fluorescence measurements. Acclimation to low temperature enhanced epidermal UV-B screening and improved the UV-B resistance considerably. Differences in the apparent UV-B sensitivity of PS II between plants grown in moderate or acclimated to cool temperatures were strongly diminished when damage was related to the UV-B radiation reaching the mesophyll (UV-Bint) as calculated from incident UV-B irradiance and epidermal UV-B transmittance. Evidence is presented that the remaining differences in sensitivity are caused by an increased rate of repair in plants acclimated to 9 °C. The data suggest that enhanced epidermal UV-B screening at low temperature functions to compensate for slower repair of UV-B damage at these temperatures. It is proposed that the UV-B irradiance reaching the mesophyll should be considered as an important parameter in experiments on UV-B resistance of plants.
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Affiliation(s)
- Matthias Schultze
- Botanical Institute, Christian-Albrechts Universität zu Kiel, Am Botanischen Garten 1-9, D-24118, Kiel, Germany; BioConsult SH GmbH & Co KG, Schobüller Straße 36, D-25813, Husum, Germany
| | - Wolfgang Bilger
- Botanical Institute, Christian-Albrechts Universität zu Kiel, Am Botanischen Garten 1-9, D-24118, Kiel, Germany.
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19
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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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20
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Grašič M, Budak V, Klančnik K, Gaberščik A. Optical properties of halophyte leaves are affected by the presence of salt on the leaf surface. Biologia (Bratisl) 2017. [DOI: 10.1515/biolog-2017-0125] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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21
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Palmieri L, Masuero D, Martinatti P, Baratto G, Martens S, Vrhovsek U. Genotype-by-environment effect on bioactive compounds in strawberry (Fragaria x ananassa Duch.). JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:4180-4189. [PMID: 28239870 DOI: 10.1002/jsfa.8290] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/22/2017] [Accepted: 02/23/2017] [Indexed: 06/06/2023]
Abstract
BACKGROUND The assessment of the relative contribution of genotype, environment and the genotype-by-environmental (G × E) interaction to the performance of varieties is necessary when determining adaptation capacity. RESULTS The influence of temperature, ultraviolet (UV)-irradiation and sunshine duration on the quality and the composition of fruits was investigated in nine strawberry cultivars grown at three different altitudes. The UV-radiation intensity affected both pH and sugar content, which were higher for most of the varieties at low altitudes, whereas total titratable acidity was less. Fruits from plants grown at low elevation generally had a higher benzoic acid derivative content. A significant correlation was found between phenylpropanoid content and UV-radiation and sunshine duration. The flavone class appeared to be affected most by the variety effect, in contrast to flavonols and ellagitannins, which were highly affected by the environment. The accumulation of a number of secondary metabolites in strawberry fruits grown in an unusual environmental condition highlighted the acclimation effects in terms of the response of plants to abiotic stress. Finally, the genetic factor only appears to be more influential for the varieties 'Sveva' and 'Marmolada' with respect to all of the parameters considered. CONCLUSION A 'plant environmental metabolomics' approach has been used successfully to assess the phenotypic plasticity of varieties that showed different magnitudes with respect to the relationship between environmental conditions and the accumulation of healthy compounds. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Luisa Palmieri
- Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all'Adige, Italy
| | - Domenico Masuero
- Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all'Adige, Italy
| | - Paolo Martinatti
- Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all'Adige, Italy
| | - Giuseppe Baratto
- Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all'Adige, Italy
| | - Stefan Martens
- Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all'Adige, Italy
| | - Urska Vrhovsek
- Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all'Adige, Italy
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Mao B, Yin H, Wang Y, Zhao TH, Tian RR, Wang W, Ye JS. Combined effects of O3 and UV radiation on secondary metabolites and endogenous hormones of soybean leaves. PLoS One 2017; 12:e0183147. [PMID: 28806739 PMCID: PMC5555667 DOI: 10.1371/journal.pone.0183147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 07/31/2017] [Indexed: 11/29/2022] Open
Abstract
Enhanced ultraviolet radiation (UV) and elevated tropospheric ozone (O3) may individually cause reductions in the growth and productivity of important agricultural crops. However, research regarding their combined effects on important agricultural crops is still scarce, especially on changes in secondary metabolites and endogenous hormones, which are important protective substances and signal components that control plant responses to environment stresses. In this study, using an experimental setup of open top chambers, we monitored the responses of seed yield per plant, leaf secondary metabolites and leaf endogenous hormones under the stress of elevated O3 and enhanced UV radiation individually, as well as their combined stress. The results indicated that elevated O3 (110 ± 10 nmol mol-1 for 8 hours per day) and enhanced UV radiation (1.73 kJ h-1 m-2) significantly decreased seed yield per plant. Concentrations of rutin, queretin and total flavonoids were significantly increased under the elevated O3 treatment or the enhanced UV radiation treatment or the combination treatment at flowering and podding stages, and concentrations of rutin, queretin and total flavonoids showed significant correlations with seed yield per plant. Concentrations of ABA and IAA decreased under the three treatments. There was a significant positive correlation between the ABA concentration and seed yield and a negative correlation between the IAA concentration and seed yield. We concluded that the combined stress of elevated O3 and UV radiation significantly decreased seed yield per plant. Yield reduction was associated with changes in the concentrations of flavonoids, ABA and IAA in soybean leaves. The effects of the combined O3 and UV stress were always greater than those of the individual stresses alone.
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Affiliation(s)
- Bing Mao
- Postdoctoral Research Station of Crop Science, College of Agronomy, Shenyang Agricultural University, Shenyang, China
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Hong Yin
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Yan Wang
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Tian-Hong Zhao
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Rong-Rong Tian
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Wei Wang
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Jia-Shu Ye
- National Field Observation and Research Station of Shenyang Agro-ecosystems, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
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Environmental effects of ozone depletion and its interactions with climate change: Progress report, 2016. Photochem Photobiol Sci 2017; 16:107-145. [PMID: 28124708 PMCID: PMC6400464 DOI: 10.1039/c7pp90001e] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 01/05/2017] [Indexed: 12/12/2022]
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 two focal issues. The first focus is the effects of UV radiation on human health, animals, plants, biogeochemistry, air quality, and materials. The second focus is on interactions between UV radiation and global climate change and how these may affect humans and the environment. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than previously believed. As a result of this, human health and environmental issues will be longer-lasting and more regionally variable. Like the other Panels, the EEAP produces a detailed report 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 Progress Reports of the relevant scientific findings. The most recent of these was for 2015 (Photochem. Photobiol. Sci., 2016, 15, 141-147). The present Progress Report for 2016 assesses some of the highlights and new insights with regard to the interactive nature of the direct and indirect effects of UV radiation, atmospheric processes, and climate change. The more detailed Quadrennial Assessment will be made available in 2018.
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24
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Golob A, Kavčič J, Stibilj V, Gaberščik A, Vogel-Mikuš K, Germ M. The effect of selenium and UV radiation on leaf traits and biomass production in Triticum aestivum L. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 136:142-149. [PMID: 27865114 DOI: 10.1016/j.ecoenv.2016.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/09/2016] [Accepted: 11/12/2016] [Indexed: 05/17/2023]
Abstract
UV radiation as an evolutionarily important environmental factor, significantly affects plants traits and alters the effects of other environmental factors. Single and combined effects of ambient UV radiation, its exclusion, and Se foliar treatments on Si concentrations and production of Si phytoliths in wheat (Triticum aestivum L.) cv. 'Reska' were studied. The effects of these treatments on growth parameters of the plants, structural and biochemical traits of the leaves, and interactions of the leaves with light, as Si incrustation is the first barrier to light at the leaf surface were also examined. Under ambient UV radiation and foliar treatment with 10mgL-1 sodium selenate solution, there was a trade-off between the plant investment in primary and secondary metabolism, as the production of UV-absorbing compounds was enhanced while photosynthetic pigment levels were reduced. Independent of Se treatment, ambient UV radiation lowered respiratory potential, Ca concentration, and leaf thickness, and increased Si concentration, Si phytoliths formation, and cuticle thickness. The Se treatment has little effect on plant traits and biomass production but it increased Se concentrations in the plants by >100-fold, independent of UV radiation. In combination with UV radiation Se strengthen the protection of plants against stress by increasing the amount of UV absorbing compounds, light reflectance and transmittance.
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Affiliation(s)
- Aleksandra Golob
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia.
| | - Jan Kavčič
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | | | - Alenka Gaberščik
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - Katarina Vogel-Mikuš
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia; Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Mateja Germ
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
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25
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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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26
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Environmental effects of ozone depletion and its interactions with climate change: progress report, 2015. Photochem Photobiol Sci 2016; 15:141-74. [PMID: 26822392 DOI: 10.1039/c6pp90004f] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Environmental Effects Assessment Panel (EEAP) is one of three Panels that regularly informs the Parties (countries) to the Montreal Protocol on the effects of ozone depletion and the consequences of climate change interactions with respect to human health, animals, plants, biogeochemistry, air quality, and materials. The Panels provide a detailed assessment report every four years. The most recent 2014 Quadrennial Assessment by the EEAP was published as a special issue of seven papers in 2015 (Photochem. Photobiol. Sci., 2015, 14, 1-184). The next Quadrennial Assessment will be published in 2018/2019. In the interim, the EEAP generally produces an annual update or progress report of the relevant scientific findings. The present progress report for 2015 assesses some of the highlights and new insights with regard to the interactive nature of the effects of UV radiation, atmospheric processes, and climate change.
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27
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Barnes PW, Flint SD, Tobler MA, Ryel RJ. Diurnal adjustment in ultraviolet sunscreen protection is widespread among higher plants. Oecologia 2016; 181:55-63. [PMID: 26809621 DOI: 10.1007/s00442-016-3558-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/12/2016] [Indexed: 01/26/2023]
Abstract
The accumulation of ultraviolet (UV)-absorbing compounds (flavonoids and related phenylpropanoids) in the epidermis of higher plants reduces the penetration of solar UV radiation to underlying tissues and is a primary mechanism of acclimation to changing UV conditions resulting from ozone depletion and climate change. Previously we reported that several herbaceous plant species were capable of rapid, diurnal adjustments in epidermal UV transmittance (T UV), but how widespread this phenomenon is among plants has been unknown. In the present study, we tested the generality of this response by screening 37 species of various cultivated and wild plants growing in four locations spanning a gradient of ambient solar UV and climate (Hawaii, Utah, Idaho and Louisiana). Non-destructive measurements of adaxial T UV indicated that statistically significant midday decreases in T UV occurred in 49 % of the species tested, including both herbaceous and woody growth forms, and there was substantial interspecific variation in the magnitude of these changes. In general, plants in Louisiana exhibited larger diurnal changes in T UV than those in the other locations. Moreover, across all taxa, the magnitude of these changes was positively correlated with minimum daily air temperatures but not daily UV irradiances. Results indicate that diurnal changes in UV shielding are widespread among higher plants, vary both within and among species and tend to be greatest in herbaceous plants growing in warm environments. These findings suggest that plant species differ in their UV protection "strategies" though the functional and ecological significance of this variation in UV sunscreen protection remains unclear at present.
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Affiliation(s)
- Paul W Barnes
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, 6363 St. Charles Avenue, New Orleans, LA, 70118, USA.
| | - Stephan D Flint
- Department of Forest, Rangeland and Fire Sciences, UIPO 441135, University of Idaho, Moscow, ID, 83844-1135, USA
| | - Mark A Tobler
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, 6363 St. Charles Avenue, New Orleans, LA, 70118, USA
| | - Ronald J Ryel
- Department of Wildland Resources, Utah State University, 5230 Old Main Hill, Logan, UT, 84322-5230, USA
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28
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Barnes PW, Tobler MA, Keefover-Ring K, Flint SD, Barkley AE, Ryel RJ, Lindroth RL. Rapid modulation of ultraviolet shielding in plants is influenced by solar ultraviolet radiation and linked to alterations in flavonoids. PLANT, CELL & ENVIRONMENT 2016; 39:222-30. [PMID: 26177782 DOI: 10.1111/pce.12609] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/02/2015] [Accepted: 07/05/2015] [Indexed: 05/20/2023]
Abstract
The accumulation of ultraviolet (UV)-absorbing compounds (flavonoids and related phenylpropanoids) and the resultant decrease in epidermal UV transmittance (TUV ) are primary protective mechanisms employed by plants against potentially damaging solar UV radiation and are critical components of the overall acclimation response of plants to changing solar UV environments. Whether plants can adjust this UV sunscreen protection in response to rapid changes in UV, as occurs on a diurnal basis, is largely unexplored. Here, we use a combination of approaches to demonstrate that plants can modulate their UV-screening properties within minutes to hours, and these changes are driven, in part, by UV radiation. For the cultivated species Abelmoschus esculentus, large (30-50%) and reversible changes in TUV occurred on a diurnal basis, and these adjustments were associated with changes in the concentrations of whole-leaf UV-absorbing compounds and several quercetin glycosides. Similar results were found for two other species (Vicia faba and Solanum lycopersicum), but no such changes were detected in Zea mays. These findings reveal a much more dynamic UV-protection mechanism than previously recognized, raise important questions concerning the costs and benefits of UV-protection strategies in plants and have practical implications for employing UV to enhance crop vigor and quality in controlled environments.
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Affiliation(s)
- Paul W Barnes
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, New Orleans, LA, 70118, USA
| | - Mark A Tobler
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, New Orleans, LA, 70118, USA
| | - Ken Keefover-Ring
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Stephan D Flint
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID, 83844, USA
| | - Anne E Barkley
- Department of Biological Sciences and Environment Program, Loyola University New Orleans, New Orleans, LA, 70118, USA
| | - Ronald J Ryel
- Department of Wildland Resources, Utah State University, Logan, UT, 84322, USA
| | - Richard L Lindroth
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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