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Liu Q, Cui R, Du Y, Shen J, Jin C, Zhou X. The green tide causative-species Ulva prolifera responding to exposure to oil and dispersant. Heliyon 2024; 10:e29641. [PMID: 38698977 PMCID: PMC11064083 DOI: 10.1016/j.heliyon.2024.e29641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/08/2024] [Accepted: 04/11/2024] [Indexed: 05/05/2024] Open
Abstract
In order to study the role of oil spills in the occurrence of green tide in the Yellow Sea, the physiological characteristics and photosynthetic activities of green tide causative-species Ulva prolifera was monitored under different conditions including two oil water-accommodated fractions (WAFs) of diesel oil and crude oil, dispersed water-accommodated fractions (DWAFs) and dispersant GM-2. The results showed that, the physiological parameters of U. prolifera including the growth, pigment, carbohydrate and protein contents decreased with the increased diesel oil WAF (WAFDO) concentration, while crude oil WAF (WAFCO) showed low concentration induction and high concentration inhibition effect. In addition, with the increase of WAFs concentration, two antioxidant activities were activated. However, compared with WAFDO alone and WAFCO alone, the mixture of oil and dispersant enhanced the toxicity on the above physiological characteristics of U. prolifera. On the other hand, the photosynthetic efficiency of U. prolifera showed a similar trend. Two WAFs showed significant concentration effects on the chlorophyll-a fluorescence transients and JIP-test. The addition of dispersant further blocked the electron flow beyond QA and from plastoquinone (PQ) to PSI acceptor side, damaged the active OEC centers at the PSII donor side, suppressed the pool size and the reduction rate of PSI acceptor side, and reduced the energy transfer efficiency between PSII functional units. These results implied that the crude oil spills may induce the formation of U. prolifera green tide, and the oil dispersant GM-2 used after the oil spills is unlikely to further stimulate the scale of bloom, while the diesel oil spills is always not conducive to the outbreak of green tide of U. prolifera.
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Affiliation(s)
- Qing Liu
- Marine Science and Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Ruifei Cui
- Marine Science and Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Yuxin Du
- Marine Science and Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Junjie Shen
- Marine Science and Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Cuili Jin
- Marine Science and Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Xiaojian Zhou
- Marine Science and Technology Institute, College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China
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Xu J, Zhao X, Zhong Y, Qu T, Sun B, Zhang H, Hou C, Zhang Z, Tang X, Wang Y. Acclimation of intertidal macroalgae Ulva prolifera to UVB radiation: the important role of alternative oxidase. BMC PLANT BIOLOGY 2024; 24:143. [PMID: 38413873 PMCID: PMC10900725 DOI: 10.1186/s12870-024-04762-w] [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: 04/11/2023] [Accepted: 01/23/2024] [Indexed: 02/29/2024]
Abstract
BACKGROUND Solar radiation is primarily composed of ultraviolet radiation (UVR, 200 - 400 nm) and photosynthetically active radiation (PAR, 400 - 700 nm). Ultraviolet-B (UVB) radiation accounts for only a small proportion of sunlight, and it is the primary cause of plant photodamage. The use of chlorofluorocarbons (CFCs) as refrigerants caused serious ozone depletion in the 1980s, and this had led to an increase in UVB. Although CFC emissions have significantly decreased in recent years, UVB radiation still remains at a high intensity. UVB radiation increase is an important factor that influences plant physiological processes. Ulva prolifera, a type of macroalga found in the intertidal zone, is intermittently exposed to UVB. Alternative oxidase (AOX) plays an important role in plants under stresses. This research examines the changes in AOX activity and the relationships among AOX, photosynthesis, and reactive oxygen species (ROS) homeostasis in U. prolifera under changes in UVB and photosynthetically active radiation (PAR). RESULTS UVB was the main component of solar radiation impacting the typical intertidal green macroalgae U. prolifera. AOX was found to be important during the process of photosynthesis optimization of U. prolifera due to a synergistic effect with non-photochemical quenching (NPQ) under UVB radiation. AOX and glycolate oxidase (GO) worked together to achieve NADPH homeostasis to achieve photosynthesis optimization under changes in PAR + UVB. The synergism of AOX with superoxide dismutase (SOD) and catalase (CAT) was important during the process of ROS homeostasis under PAR + UVB. CONCLUSIONS AOX plays an important role in the process of photosynthesis optimization and ROS homeostasis in U. prolifera under UVB radiation. This study provides further insights into the response of intertidal macroalgae to solar light changes.
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Grants
- No. LSKJ202203605 Laoshan Laboratory
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. U1806213 and U1606404 NSFC-Shandong Joint Fund
- Nos. U1806213 and U1606404 NSFC-Shandong Joint Fund
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Affiliation(s)
- Jinhui Xu
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Xinyu Zhao
- Laoshan Laboratory, 1 Wenhai Road, Qingdao, 266237, China.
| | - Yi Zhong
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Tongfei Qu
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Baixue Sun
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Huanxin Zhang
- College of Geography and Environment, Shandong Normal University, 1 Daxue Road, Jinan, 250000, China
| | - Chengzong Hou
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Zhipeng Zhang
- Tianjin Research Institute for Water Transport Engineering, Ministry of Transport, Tianjin, 300456, China
| | - Xuexi Tang
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, 1 Wenhai Road, Qingdao, 266237, China
| | - Ying Wang
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, 1 Wenhai Road, Qingdao, 266237, China.
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Bhagooli R, Mattan-Moorgawa S, Kaullysing D, Louis YD, Gopeechund A, Ramah S, Soondur M, Pilly SS, Beesoo R, Wijayanti DP, Bachok ZB, Monrás VC, Casareto BE, Suzuki Y, Baker AC. Chlorophyll fluorescence - A tool to assess photosynthetic performance and stress photophysiology in symbiotic marine invertebrates and seaplants. MARINE POLLUTION BULLETIN 2021; 165:112059. [PMID: 33677415 DOI: 10.1016/j.marpolbul.2021.112059] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 12/30/2020] [Accepted: 01/01/2021] [Indexed: 06/12/2023]
Abstract
Chlorophyll a fluorescence is increasingly being used as a rapid, non-invasive, sensitive and convenient indicator of photosynthetic performance in marine autotrophs. This review presents the methodology, applications and limitations of chlorophyll fluorescence in marine studies. The various chlorophyll fluorescence tools such as Pulse-Amplitude-Modulated (PAM) and Fast Repetition Rate (FRR) fluorometry used in marine scientific studies are discussed. Various commonly employed chlorophyll fluorescence parameters are elaborated. The application of chlorophyll fluorescence in measuring natural variations, stress, stress tolerance and acclimation/adaptation to changing environment in primary producers such as microalgae, macroalgae, seagrasses and mangroves, and marine symbiotic invertebrates, namely symbiotic sponges, hard corals and sea anemones, kleptoplastic sea slugs and giant clams is critically assessed. Stressors include environmental, biological, physical and chemical ones. The strengths, limitations and future perspectives of the use of chlorophyll fluorescence technique as an assessment tool in symbiotic marine organisms and seaplants are discussed.
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Affiliation(s)
- Ranjeet Bhagooli
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius; The Society of Biology (Mauritius), Réduit, Mauritius; Institute of Oceanography and Environment (INOS), Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia.
| | - Sushma Mattan-Moorgawa
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Deepeeka Kaullysing
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Yohan Didier Louis
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | - Arvind Gopeechund
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Sundy Ramah
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | - Mouneshwar Soondur
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius; The Biodiversity and Environment Institute, Réduit, Mauritius
| | - Sivajyodee Sannassy Pilly
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | - Rima Beesoo
- Department of Biosciences & Ocean Studies, Faculty of Science & Pole of Research Excellence, Sustainable Marine Biodiversity Research Group, University of Mauritius, Réduit 80837, Mauritius
| | | | - Zainudin Bin Bachok
- Institute of Oceanography and Environment (INOS), Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Víctor Cubillos Monrás
- Instituto de Ciencias Marinas y Limnológicas, Laboratorio Costero de Recursos Acuáticos de Calfuco, Universidad Austral de Chile, Valdivia, Chile
| | | | - Yoshimi Suzuki
- Shizuoka University, 836 Oya, Suruga, Shizuoka, Shizuoka, Japan
| | - Andrew Charles Baker
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
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4
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Yang Y, Li HG, Wang J, Wang HL, He F, Su Y, Zhang Y, Feng CH, Niu M, Li Z, Liu C, Yin W, Xia X. ABF3 enhances drought tolerance via promoting ABA-induced stomatal closure by directly regulating ADF5 in Populus euphratica. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:7270-7285. [PMID: 32822499 DOI: 10.1093/jxb/eraa383] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 08/17/2020] [Indexed: 05/20/2023]
Abstract
Water availability is a main limiting factor for plant growth, development, and distribution throughout the world. Stomatal movement mediated by abscisic acid (ABA) is particularly important for drought adaptation, but the molecular mechanisms in trees are largely unclear. Here, we isolated an ABA-responsive element binding factor, PeABF3, in Populus euphratica. PeABF3 was preferentially expressed in the xylem and young leaves, and was induced by dehydration and ABA treatments. PeABF3 showed transactivation activity and was located in the nucleus. To study its functional mechanism in poplar responsive to drought stress, transgenic triploid white poplars (Populus tomentosa 'YiXianCiZhu B385') overexpressing PeABF3 were generated. PeABF3 overexpression significantly enhanced stomatal sensitivity to exogenous ABA. When subjected to drought stress, PeABF3 overexpression maintained higher photosynthetic activity and promoted cell membrane integrity, resulting in increased water-use efficiency and enhanced drought tolerance compared with wild-type controls. Moreover, a yeast one-hybrid assay and an electrophoretic mobility shift assay revealed that PeABF3 activated the expression of Actin-Depolymerizing Factor-5 (PeADF5) by directly binding to its promoter, promoting actin cytoskeleton remodeling and stomatal closure in poplar under drought stress. Taken together, our results indicate that PeABF3 enhances drought tolerance via promoting ABA-induced stomatal closure by directly regulating PeADF5 expression.
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Affiliation(s)
- Yanli Yang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Hui-Guang Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Jie Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Hou-Ling Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Fang He
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Yanyan Su
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Ying Zhang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Cong-Hua Feng
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Mengxue Niu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Zhonghai Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Chao Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Weilun Yin
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Xinli Xia
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
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5
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Kolomeichuk LV, Efimova MV, Zlobin IE, Kreslavski VD, Murgan OK, Kovtun IS, Khripach VA, Kuznetsov VV, Allakhverdiev SI. 24-Epibrassinolide alleviates the toxic effects of NaCl on photosynthetic processes in potato plants. PHOTOSYNTHESIS RESEARCH 2020; 146:151-163. [PMID: 31939071 DOI: 10.1007/s11120-020-00708-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/06/2020] [Indexed: 06/10/2023]
Abstract
Brassinosteroids are promising agents for alleviating the negative effects of salinity on plants, but the mechanism of their protective action is far from being understood. We investigated the effect of pretreatment with 24-epibrassinolide (24-EBL) on the photosynthetic and physiological parameters of potato plants under progressive salinity stress caused by root application of 100 mM NaCl. Salinity clearly inhibited primary photosynthetic processes in potato plants by reducing the contents of photosynthetic pigments, photosynthetic electron transport and photosystem II (PSII) maximal and effective quantum yields. These negative effects of salinity on primary photosynthetic processes were mainly due to toxic ionic effects on the plant's ability to oxidize the plastoquinone pool. Pretreatment with 24-EBL alleviated this stress effect and allowed the maintenance of plastoquinone pool oxidation and the efficiency of photosystem II photochemistry to be at the same levels as those in unstressed plants; however, the pretreatment did not affect the photosynthetic pigment content. 24-EBL pretreatment clearly alleviated the decrease in leaf osmotic potential under salinity stress. The stress-induced increases in lipid peroxidation and proline contents were not changed under brassinosteroid pretreatment. However, 24-EBL pretreatment increased the peroxidase activity and improved the K+/Na+ ratio in potato leaves, which were likely responsible for the protective 24-EBL action under salt stress.
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Affiliation(s)
| | - Marina V Efimova
- National Research Tomsk State University, Tomsk, Russian Federation
| | - Ilya E Zlobin
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russian Federation.
| | - Vladimir D Kreslavski
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russian Federation
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Russian Federation
| | - Ol'ga K Murgan
- National Research Tomsk State University, Tomsk, Russian Federation
| | - Irina S Kovtun
- National Research Tomsk State University, Tomsk, Russian Federation
| | - Vladimir A Khripach
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Belarus, Belarus
| | - Vladimir V Kuznetsov
- National Research Tomsk State University, Tomsk, Russian Federation
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Suleyman I Allakhverdiev
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russian Federation.
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Russian Federation.
- M.V. Lomonosov Moscow State University, Moscow, Russia.
- College of Science, King Saud University, Riyadh, Saudi Arabia.
- Institute of Molecular Biology and Biotechnology, ANAS, Baku, Azerbaijan.
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow, Russian Federation.
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6
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Li N, Tong M, Glibert PM. Effect of allelochemicals on photosynthetic and antioxidant defense system of Ulva prolifera. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 224:105513. [PMID: 32504860 DOI: 10.1016/j.aquatox.2020.105513] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 04/28/2020] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Ulva prolifera is a macroalgae that forms massive blooms, negatively impacting natural communities, aquaculture operations and recreation. The effects of the natural products, eugenol, β-myrcene, citral and nonanoic acid on the growth rate, antioxidative defense system and photosynthesis of Ulva prolifera were investigated as a possible control strategy for this harmful taxon. Negative effects on growth were observed with all four chemicals, due to the excessive production of reactive oxygen species and oxidative damage to the thalli. However, the response of U. prolifera under the four chemicals stress was different at the cellular level. β-myrcene, the most effective compound in terms of growth inhibition, induced oxidative stress as shown by the damage of total antioxidant capacity (T-AOC) and the downregulation of the glutathione-ascorbate (GSH-ASA) cycle which inhibited the antioxidative system. This chemical also inhibited photosynthesis and photoprotection mechanisms in U. prolifera, resulting in growth limitation. In contrast, U. prolifera was less affected by the second tested chemical, eugenol, and showed no significant change on photosynthetic efficiency in the presence of the chemical. The inhibition effects of the third and fourth tested chemicals, nonanoic acid and citralon, on growth and on the antioxidant defense system in U. prolifera were inferior. These results provide a potential avenue for controlling green tides in the future.
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Affiliation(s)
- Naicheng Li
- Ocean College, Zhejiang University, Zhoushan, 316021, China
| | - Mengmeng Tong
- Ocean College, Zhejiang University, Zhoushan, 316021, China.
| | - Patricia M Glibert
- University of Maryland Center for Environment Science, Horn Point Laboratory, Cambridge, MD, 21613, USA
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7
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Zhou L, Gao S, Huan L, Wu S, Wang G, Gu W. Enzyme activities suggest that the NAD-ME C4 type CCM exist in Ulva sp. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Cruces E, Rautenberger R, Cubillos VM, Ramírez-Kushel E, Rojas-Lillo Y, Lara C, Montory JA, Gómez I. Interaction of Photoprotective and Acclimation Mechanisms in Ulva rigida (Chlorophyta) in Response to Diurnal Changes in Solar Radiation in Southern Chile. JOURNAL OF PHYCOLOGY 2019; 55:1011-1027. [PMID: 31222742 DOI: 10.1111/jpy.12894] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
Species of the genus Ulva (Chlorophyta) are regarded as opportunistic organisms, which efficiently adjust their metabolism to the prevailing environmental conditions. In this study, changes in chlorophyll-a fluorescence-based photoinhibition of photosynthesis, electron transport rates, photosynthetic pigments, lipid peroxidation, total phenolic compounds, and antioxidant metabolism were investigated during a diurnal cycle of natural solar radiation in summer (for 12 h) under two treatments: photosynthetically active radiation (PAR: 400-700 nm) and PAR+ ultraviolet (UV) radiation (280-700 nm). In the presence of PAR alone, Ulva rigida showed dynamic photoinhibition, and photosynthetic parameters and pigment concentrations decreased with the intensification of the radiation. On the other hand, under PAR+UV conditions a substantial decline up to 43% was detected and an incomplete fluorescence recovery, also, P-I curve values remained low in relation to the initial condition. The phenolic compounds increased their concentration only in UV radiation treatments without showing a correlation with the antioxidant activity. The enzimatic activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX) increased over 2-fold respect at initial values during the onset of light intensity. In contrast, catalase (CAT) increased its activity rapidly in response to the radiation stress to reach maxima at 10 a.m. and decreasing during solar. The present study suggests that U. rigida is capable of acclimating to natural radiation stress relies on a concerted action of various physiological mechanisms that act at different times of the day and under different levels of environmental stress.
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Affiliation(s)
- Edgardo Cruces
- Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O'Higgins, General Gana 1780, Santiago, 8370854, Chile
- Centro de Investigaciones Costeras-Universidad de Atacama (CIC-UDA), Universidad de Atacama, Avenida Copayapu 485, Copiapó, Atacama, Chile
| | - Ralf Rautenberger
- Division of Biotechnology and Plant Health, Department of Algae Production, Norwegian Institute for Bioeconomy Research (NIBIO), Kudalsveien 6, 8027, Bodø, Norway
| | - Víctor Mauricio Cubillos
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
- Laboratorio Costero de Recursos Acuáticos de Calfuco, Universidad Austral de Chile, Valdivia, Chile
| | - Eduardo Ramírez-Kushel
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
| | - Yesenia Rojas-Lillo
- Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O'Higgins, General Gana 1780, Santiago, 8370854, Chile
| | - Carlos Lara
- Centro de Investigación en Recursos Naturales y Sustentabilidad (CIRENYS), Universidad Bernardo O'Higgins, Santiago, 8370993, Chile
| | | | - Iván Gómez
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
- Research Center FONDAP Dynamic of High Latitude Marine Ecosystems de (IDEAL), Valdivia, Chile
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9
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Zheng Z, Gao S, Wang G. High salt stress in the upper part of floating mats of Ulva prolifera, a species that causes green tides, enhances non-photochemical quenching. JOURNAL OF PHYCOLOGY 2019; 55:1041-1049. [PMID: 31062364 DOI: 10.1111/jpy.12881] [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: 12/11/2018] [Accepted: 04/19/2019] [Indexed: 06/09/2023]
Abstract
Salt stress is a major abiotic stress factor that can induce many adverse effects on photosynthetic organisms. Plants and algae have developed several mechanisms that help them respond to adverse environments. Non-photochemical quenching (NPQ) is one of these mechanisms. The thalli of algae in the intertidal zone that are attached to rocks can be subjected to salt stress for a short period of time due to the rise and fall of the tide. Ulva prolifera causes green tides and can form floating mats when green tides occur and the upper part of the thalli is subjected to high salt stress for a long period of time. In this study, we compared the Ulva prolifera photosynthetic activities and NPQ kinetics when it is subjected to different salinities over various periods of time. Thalli exposed to a salinity of 90 for 4 d showed enhanced NPQ, and photosynthetic activities decreased from 60 min after exposure up to 4 d. This indicated that the induction of NPQ in Ulva prolifera under salt stress was closely related to the stressing extent and stressing time. The enhanced NPQ in the treated samples exposed for 4 d may explain why the upper layer of the floating mats formed by Ulva prolifera thalli were able to survive in the harsh environment. Further inhibitor experiments demonstrated that the enhanced NPQ was xanthophyll cycle and transthylakoid proton gradient-dependent. However, photosystem II subunit S and light-harvesting complex stress-related protein didn't over accumulate and may not be responsible for the enhanced NPQ.
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Affiliation(s)
- Zhenbing Zheng
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Shan Gao
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Guangce Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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10
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Zheng Z, Gao S, Wang G. Far red light induces the expression of LHCSR to trigger nonphotochemical quenching in the intertidal green macroalgae Ulva prolifera. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101512] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Wang W, Xu Y, Chen T, Xing L, Xu K, Xu Y, Ji D, Chen C, Xie C. Regulatory mechanisms underlying the maintenance of homeostasis in Pyropia haitanensis under hypersaline stress conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:168-179. [PMID: 30690352 DOI: 10.1016/j.scitotenv.2019.01.214] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Accepted: 01/18/2019] [Indexed: 05/10/2023]
Abstract
Intertidal macroalgae are highly resistant to hypersaline stress conditions. However, the underlying mechanism remains unknown. In the present study, the mechanism behind Pyropia haitanensis responses to two hypersaline stress conditions [100‰ (HSS_100) and 110‰ (HSS_110)] was investigated via analyses of physiological and transcriptomic changes. We observed that the differences between the responses of Py. haitanensis to HSS_100 and HSS_110 conditions involved the following three aspects: osmotic regulation, ionic homeostasis, and adjustment to secondary stresses. First, the water retention of Py. haitanensis was maintained through increased expansin production under HSS_100 conditions, while cell wall pectin needed to be protected from hydrolysis via the increased abundance of a pectin methylesterase inhibitor under HSS_110 conditions. Meanwhile, Py. haitanensis achieved stable and rapid osmotic adjustments because of the coordinated accumulation of inorganic ions (K+, Na+, and Cl-) and organic osmolytes (glycine betaine and trehalose) under HSS_100 conditions, but not under HSS_110 conditions. Second, Py. haitanensis maintained a higher K+/Na+ ratio under HSS_100 conditions than under HSS_110 conditions, mainly via the export of Na+ into the apoplast rather than compartmentalizing it into the vacuoles, and the enhanced uptake and retention of K+. However, K+/Na+ homeostasis was not completely disrupted during a short-term exposure to HSS_110 conditions. Finally, the Py. haitanensis antioxidant system scavenged more ROS and synthesized more heat shock proteins under HSS_100 conditions than under HSS_110 conditions, although thalli may have been able to maintain a certain redox balance during a short-term exposure to HSS_110 conditions. These differences may explain why Py. haitanensis can adapt to HSS_100 conditions rather than HSS_110 conditions, and also why the thalli exposed to HSS_110 conditions can recover after being transferred to normal seawater. Thus, the data presented herein may elucidate the mechanisms enabling Pyropia species to tolerate the sudden and periodic changes in salinity typical of intertidal systems.
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Affiliation(s)
- Wenlei Wang
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Yan Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - TianXiang Chen
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Lei Xing
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Kai Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Yan Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Dehua Ji
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Changsheng Chen
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Chaotian Xie
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China.
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Gao S, Chi Z, Chen H, Zheng Z, Weng Y, Wang G. A Supercomplex, of Approximately 720 kDa and Composed of Both Photosystem Reaction Centers, Dissipates Excess Energy by PSI in Green Macroalgae Under Salt Stress. PLANT & CELL PHYSIOLOGY 2019; 60:166-175. [PMID: 30295873 DOI: 10.1093/pcp/pcy201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/01/2018] [Indexed: 06/08/2023]
Abstract
The thylakoid membranes of plants play a critical role in electron transfer and energy fixation, and are highly dynamic. So far, studies on the thylakoid membranes have mainly focused on microalgae and higher plants, yet very little information is available on the macroalgal thylakoids. Here, we studied the structure and organization of the thylakoid membranes in Ulva prolifera, a representative species of the green macroalgae. We found that U. prolifera had few but long loosely stacked membranes which lack the conventional grana found in higher plants. However, the thylakoid membrane complexes demonstrate lateral heterogeneity. Moreover, we found a supercomplex composed of PSII, light-harvesting complex II (LHCII) and PSI from U. prolifera under salt stress. The supercomplex is approximately 720 kDa, and includes the two important photoprotection proteins, the PSII S subunit (PsbS) and the light-harvesting complex stress-related protein (LhcSR), as well as xanthophyll cycle pigments (violaxanthin, antheraxanthin and zeaxanthin). Time-resolved fluorescence analysis suggested that, in the supercomplex, excitation energy could efficiently be transferred from PSII to PSI, even when PSII was inhibited, a function which disappeared when the supercomplex was incubated in mild detergent. We suggest that the supercomplex might be an important mechanism to dissipate excess energy by PSI in green macroalgae under salt stress.
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Affiliation(s)
- Shan Gao
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Zhen Chi
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hailong Chen
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Zhenbing Zheng
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yuxiang Weng
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Guangce Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
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13
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Zhang C, Peng X, Guo X, Tang G, Sun F, Liu S, Xi Y. Transcriptional and physiological data reveal the dehydration memory behavior in switchgrass ( Panicum virgatum L.). BIOTECHNOLOGY FOR BIOFUELS 2018; 11:91. [PMID: 29619087 PMCID: PMC5879616 DOI: 10.1186/s13068-018-1088-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 03/21/2018] [Indexed: 05/05/2023]
Abstract
BACKGROUND Switchgrass (Panicum virgatum L.) is a model biofuel plant because of its high biomass, cellulose-richness, easy degradation to ethanol, and the availability of extensive genomic information. However, a little is currently known about the molecular responses of switchgrass plants to dehydration stress, especially multiple dehydration stresses. RESULTS Studies on the transcriptional profiles of 35-day-old tissue culture plants revealed 741 dehydration memory genes. Gene Ontology and pathway analysis showed that these genes were enriched in phenylpropanoid biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. Further analysis of specific pathways combined with physiological data suggested that switchgrass improved its dehydration resistance by changing various aspects of its responses to secondary dehydration stress (D2), including the regulation of abscisic acid (ABA) and jasmonic acid (JA) biosynthesis and signal transduction, the biosynthesis of osmolytes (l-proline, stachyose and trehalose), energy metabolism (i.e., metabolic process relating to photosynthetic systems, glycolysis, and the TCA cycle), and lignin biosynthesis. The transcriptional data and chemical substance assays showed that ABA was significantly accumulated during both primary (D1) and secondary (D2) dehydration stresses, whereas JA accumulated during D1 but became significantly less abundant during D2. This suggests the existence of a complicated signaling network of plant hormones in response to repeated dehydration stresses. A homology analysis focusing on switchgrass, maize, and Arabidopsis revealed the conservation and species-specific distribution of dehydration memory genes. CONCLUSIONS The molecular responses of switchgrass plants to successive dehydration stresses have been systematically characterized, revealing a previously unknown transcriptional memory behavior. These results provide new insights into the mechanisms of dehydration stress responses in plants. The genes and pathways identified in this study will be useful for the genetic improvement of switchgrass and other crops.
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Affiliation(s)
- Chao Zhang
- College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Xi Peng
- College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Xiaofeng Guo
- College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Gaijuan Tang
- College of Plant Protection, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Fengli Sun
- College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Shudong Liu
- College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Yajun Xi
- College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi China
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, 712100 Shaanxi China
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Li J, Song X, Zhang Y, Pan J, Yu Z. An investigation of the space distribution of Ulva microscopic propagules and ship-based experiment of mitigation using modified clay. MARINE POLLUTION BULLETIN 2017; 117:247-254. [PMID: 28187967 DOI: 10.1016/j.marpolbul.2017.01.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/22/2017] [Accepted: 01/26/2017] [Indexed: 06/06/2023]
Abstract
Previous studies suggested that the removal of Ulva microscopic propagules (UMP) from cradle water might restrict the formation and expansion of green tides in the Yellow Sea, China. In this study, the distribution characteristics of UMP in the southern Yellow Sea was investigated, and then a flocculation experiment of UMP using modified clay (MC) was conducted at a selected station of the research cruise. The results indicated that the distribution of green algae thalli is one of the main factors that directly influence UMP distribution. UMP density was strongly negatively correlated with the distance between the sampling station and the centre of the area containing floating Ulva (r=-0.618***, n=83). >80% of the UMP was removed from the water column after MC application at a concentration of 0.1g/L, and MC applied at a concentration of 0.5g/L reduced the germination rate to 0.3%.
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Affiliation(s)
- Jing Li
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China
| | - Xiuxian Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China.
| | - Yue Zhang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China
| | - Jun Pan
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China; Research & Development Centre of Marine Environment Engineering and Technology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China
| | - Zhiming Yu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China.
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15
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Wang W, Li H, Lin X, Zhang F, Fang B, Wang Z. The effect of polar auxin transport on adventitious branches formation in Gracilaria lichenoides in vitro. PHYSIOLOGIA PLANTARUM 2016; 158:356-365. [PMID: 27145892 DOI: 10.1111/ppl.12464] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/16/2016] [Accepted: 03/29/2016] [Indexed: 06/05/2023]
Abstract
Seaweed tissue culture (STC) is an important micropropagation tool that has been applied for strain improvement, micropropagation and genetic engineering. Because the mechanisms associated with STC are poorly understood, its application to these organisms lags far behind that of tissue culture propagation of higher plants. Auxin, calcium (Ca2+ ) and hydrogen peroxide (H2 O2 ) fluxes all play key roles during plant growth and development. In this study, we therefore measured indole-3-acetic acid, Ca2+ and H2 O2 fluxes of Gracilaria lichenoides explants during adventitious branches (ABs) formation for the first time using noninvasive micro-test technology. We confirmed that polar auxin transport (PAT) also occurs in the marine red alga G. lichenoides. We additionally found that N-1-naphthylphthalamic acid may suppress auxin efflux via ABCB1 transporters and then inhibit ABs formation from the apical region of G. lichenoides segments. The involvement of Ca2+ and H2 O2 fluxes in PAT-mediated AB formation in G. lichenoides was also investigated. We propose that complex feedback among Ca2+ , H2 O2 and auxin signaling and response systems may occur during ABs polar formation in G. lichenoides explants, similar to that in higher plants. Our results provide innovative insights that should aid future elucidation of mechanisms operative during STC.
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Affiliation(s)
- Wenlei Wang
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Huanqin Li
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China
| | - Xiangzhi Lin
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China
| | - Fang Zhang
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China
| | - Baishan Fang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Zhaokai Wang
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China.
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16
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Lu X, Huan L, Gao S, He L, Wang G. NADPH from the oxidative pentose phosphate pathway drives the operation of cyclic electron flow around photosystem I in high-intertidal macroalgae under severe salt stress. PHYSIOLOGIA PLANTARUM 2016; 156:397-406. [PMID: 26337725 DOI: 10.1111/ppl.12383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 07/01/2015] [Accepted: 07/15/2015] [Indexed: 05/18/2023]
Abstract
Pyropia yezoensis (Bangiales, Rhodophyta) is a representative species of high-intertidal macroalgae, whose blades can tolerate extreme stresses, such as salt stress and desiccation. In this study, the photosystem (PS) responses of P. yezoensis blades under salt stress were studied. Our results showed that when the effective photochemical quantum yield of PS (Y) II decreased to almost zero under high salt stress, YI still had a relatively high activity rate. PSII was therefore more sensitive to salt stress than PSI. Furthermore, in the presence of 3-(3', 4'-dichlorophenyl)-1,1-dimethylurea (DCMU), YI rose as salinity increased. The YI values for DCMU-treated thalli decreased in the presence of glucose-6-phosphate dehydrogenase (EC 1.1.1.49, G6PDH) inhibitor (glucosamine, Glucm). The YI values were ∼0.09 in the presence of methyl viologen (MV) and almost zero in the presence of dibromothymoquinone (DBMIB). These results demonstrated that under severe salt stress (120‰ salinity) PSI activity was driven from a source other than PSII, and that stromal reductants probably supported the operation of PSI. Under salt stress, the starch content decreased and soluble sugar levels increased. The G6PDH and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) activities increased, but cytosolic glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12) activity decreased. Furthermore, the NADPH content increased, but NADH decreased, which suggested that soluble sugar entered the oxidative pentose phosphate pathway (OPPP). All these results suggested that NADPH from OPPP increases the cyclic electron flow around PSI in high-intertidal macroalgae under severe salt stress.
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Affiliation(s)
- Xiaoping Lu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Li Huan
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Shan Gao
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Linwen He
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Guangce Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
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Holzinger A, Herburger K, Kaplan F, Lewis LA. Desiccation tolerance in the chlorophyte green alga Ulva compressa: does cell wall architecture contribute to ecological success? PLANTA 2015; 242:477-92. [PMID: 25896374 PMCID: PMC4498240 DOI: 10.1007/s00425-015-2292-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 03/31/2015] [Indexed: 05/24/2023]
Abstract
MAIN CONCLUSION Desiccation leads to structural changes of the inner pectic cell wall layers in Ulva compressa. This contributes to protection against mechanical damage due to desiccation-rehydration cycles. Ulva compressa, characterized by rbcL phylogeny, is a common species in the Mediterranean Sea. Ulva as an intertidal species tolerates repeated desiccation-rehydration cycles in nature; the physiological and structural basis were investigated under experimental conditions here. Desiccation to 73% relative water content (RWC) led to a significant decrease of the maximum quantum yield of photosystem II (F v/F m) to about half of the initial value. A reduction to 48 or 27% RWC caused a more drastic effect and thalli were only able to recover fully from desiccation to 73% RWC. Relative electron transport rates were stimulated at 73% RWC, but decreased significantly at 48 and 27% RWC, respectively. Imaging-PAM analysis demonstrated a homogenous desiccation process within individual thallus discs. The different cell wall layers of U. compressa were characterized by standard staining procedures, i.e. calcofluor white and aniline blue for structural components (cellulose, callose), ruthenium red for pectins and toluidine blue for acidic polysaccharides. Already a reduction to 73% RWC caused severe changes of the cell walls. The inner pectin-rich layers followed the shrinkage process of the cytoplasm, while the outer denser fibrillar layers maintained their shape. In this way, the thalli were not plasmolyzed during water loss, and upon recovery not negatively influenced by any mechanical damage. Transmission electron microscopy corroborated the arrangement of the different layers clearly distinguishable by their texture and electron density. We suggest the flexibility of the pectin-rich cell wall layers as a major contribution to desiccation tolerance in Ulva.
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Affiliation(s)
- Andreas Holzinger
- Institute of Botany, Functional Plant Biology, University of Innsbruck, Sternwartestrasse 15, 6020, Innsbruck, Austria,
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