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Poirier M, Osmers P, Wilkins K, Morgan-Kiss RM, Cvetkovska M. Aberrant light sensing and motility in the green alga Chlamydomonas priscuii from the ice-covered Antarctic Lake Bonney. PLANT SIGNALING & BEHAVIOR 2023; 18:2184588. [PMID: 38126947 PMCID: PMC10012900 DOI: 10.1080/15592324.2023.2184588] [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: 06/29/2022] [Accepted: 02/20/2023] [Indexed: 12/23/2023]
Abstract
The Antarctic green alga Chlamydomonas priscuii is an obligate psychrophile and an emerging model for photosynthetic adaptation to extreme conditions. Endemic to the ice-covered Lake Bonney, this alga thrives at highly unusual light conditions characterized by very low light irradiance (<15 μmol m-2 s-1), a narrow wavelength spectrum enriched in blue light, and an extreme photoperiod. Genome sequencing of C. priscuii exposed an unusually large genome, with hundreds of highly similar gene duplicates and expanded gene families, some of which could be aiding its survival in extreme conditions. In contrast to the described expansion in the genetic repertoire in C. priscuii, here we suggest that the gene family encoding for photoreceptors is reduced when compared to related green algae. This alga also possesses a very small eyespot and exhibits an aberrant phototactic response, compared to the model Chlamydomonas reinhardtii. We also investigated the genome and behavior of the closely related psychrophilic alga Chlamydomonas sp. ICE-MDV, that is found throughout the photic zone of Lake Bonney and is naturally exposed to higher light levels. Our analyses revealed a photoreceptor gene family and a robust phototactic response similar to those in the model Chlamydomonas reinhardtii. These results suggest that the aberrant phototactic response in C. priscuii is a result of life under extreme shading rather than a common feature of all psychrophilic algae. We discuss the implications of these results on the evolution and survival of shade adapted polar algae.
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Affiliation(s)
| | - Pomona Osmers
- Department of Biology, University of Ottawa, Ottawa, OH, Canada
| | - Kieran Wilkins
- Department of Biology, University of Ottawa, Ottawa, OH, Canada
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2
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Kalra I, Wang X, Zhang R, Morgan-Kiss R. High salt-induced PSI-supercomplex is associated with high CEF and attenuation of state transitions. PHOTOSYNTHESIS RESEARCH 2023; 157:65-84. [PMID: 37347385 PMCID: PMC10484818 DOI: 10.1007/s11120-023-01032-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/05/2023] [Indexed: 06/23/2023]
Abstract
While PSI-driven cyclic electron flow (CEF) and assembly of thylakoid supercomplexes have been described in model organisms like Chlamydomonas reinhardtii, open questions remain regarding their contributions to survival under long-term stress. The Antarctic halophyte, C. priscuii UWO241 (UWO241), possesses constitutive high CEF rates and a stable PSI-supercomplex as a consequence of adaptation to permanent low temperatures and high salinity. To understand whether CEF represents a broader acclimation strategy to short- and long-term stress, we compared high salt acclimation between the halotolerant UWO241, the salt-sensitive model, C. reinhardtii, and a moderately halotolerant Antarctic green alga, C. sp. ICE-MDV (ICE-MDV). CEF was activated under high salt and associated with increased non-photochemical quenching in all three Chlamydomonas species. Furthermore, high salt-acclimated cells of either strain formed a PSI-supercomplex, while state transition capacity was attenuated. How the CEF-associated PSI-supercomplex interferes with state transition response is not yet known. We present a model for interaction between PSI-supercomplex formation, state transitions, and the important role of CEF for survival during long-term exposure to high salt.
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Affiliation(s)
- Isha Kalra
- Department of Microbiology, Miami University, Oxford, OH 45056 USA
- Present Address: Department of Biology, University of Southern California, Los Angeles, CA 90089 USA
| | - Xin Wang
- Department of Microbiology, Miami University, Oxford, OH 45056 USA
| | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132 USA
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3
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El-Hadary MH, Elsaied HE, Khalil NM, Mikhail SK. Molecular taxonomical identification and phylogenetic relationships of some marine dominant algal species during red tide and harmful algal blooms along Egyptian coasts in the Alexandria region. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:53403-53419. [PMID: 35287194 PMCID: PMC9343293 DOI: 10.1007/s11356-022-19217-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
Harmful algal blooms (HABs) threaten the aquatic ecosystems due to either poisonous effects on living organisms or oxygen-consuming. So HABs' accurate identification, including red tide, is crucial. This study aimed to molecular identification of dominant species during tide period in nine stations along Alexandria region at Egyptian costs during one year. Samples were collected weekly before water discoloration but daily during red tide intensive growth from both 50 cm below the surface and 3 m depth over the bottom from the water surface. The red tide detection was highly from early August to half of September, since its highest peak with a maximum frequency inside the Eastern Harbor. The examined cultures samples isolated during red tide had four dominant species. Peroxidase profile showed an expression pattern of three loci (Px1, Px2, and Px3) in most species. The Px2 was the only heterozygous locus among the three loci in all species. Protein profiling showed that 17 bands out of 65 were specific to the species. The phylogenetic relationships derived from profiles of protein and 18S rRNA gene operon sequences for the four isolated species were mostly similar. We identified the four dominant HABs species as Aplanochytrium sp., Chlamydomonas sp., Cryptophyceae sp., and Psammodictyon sp. based on their 18S rRNA sequences and deposited them at DDBJ/EMBL/GenBank database. Aplanochytrium sp. is recorded as a red tide causative species for the first time in the screened region despite belonging to the defunct fungi.
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Affiliation(s)
- Mona H El-Hadary
- Department of Botany and Microbiology, Faculty of Science, Damanhour University, Damanhour, Al Beheria Governorate, Egypt.
| | - Hosam E Elsaied
- National Institutes of Oceanography and Fisheries (NIOF), Al kanater Elkhiria, Al Qalyubiyah, Egypt
| | - Nehma M Khalil
- National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
| | - Samia K Mikhail
- National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
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4
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Stahl-Rommel S, Kalra I, D'Silva S, Hahn MM, Popson D, Cvetkovska M, Morgan-Kiss RM. Cyclic electron flow (CEF) and ascorbate pathway activity provide constitutive photoprotection for the photopsychrophile, Chlamydomonas sp. UWO 241 (renamed Chlamydomonas priscuii). PHOTOSYNTHESIS RESEARCH 2022; 151:235-250. [PMID: 34609708 DOI: 10.1007/s11120-021-00877-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Under environmental stress, plants and algae employ a variety of strategies to protect the photosynthetic apparatus and maintain photostasis. To date, most studies on stress acclimation have focused on model organisms which possess limited to no tolerance to stressful extremes. We studied the ability of the Antarctic alga Chlamydomonas sp. UWO 241 (UWO 241) to acclimate to low temperature, high salinity or high light. UWO 241 maintained robust growth and photosynthetic activity at levels of temperature (2 °C) and salinity (700 mM NaCl) which were nonpermissive for a mesophilic sister species, Chlamydomonas raudensis SAG 49.72 (SAG 49.72). Acclimation in the mesophile involved classic mechanisms, including downregulation of light harvesting and shifts in excitation energy between photosystem I and II. In contrast, UWO 241 exhibited high rates of PSI-driven cyclic electron flow (CEF) and a larger capacity for nonphotochemical quenching (NPQ). Furthermore, UWO 241 exhibited constitutively high activity of two key ascorbate cycle enzymes, ascorbate peroxidase and glutathione reductase and maintained a large ascorbate pool. These results matched the ability of the psychrophile to maintain low ROS under short-term photoinhibition conditions. We conclude that tight control over photostasis and ROS levels are essential for photosynthetic life to flourish in a native habitat of permanent photooxidative stress. We propose to rename this organism Chlamydomonas priscuii.
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Affiliation(s)
- Sarah Stahl-Rommel
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
- JES Tech, Houston, TX, 77058, USA
| | - Isha Kalra
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Susanna D'Silva
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Mark M Hahn
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Devon Popson
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Marina Cvetkovska
- Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Rachael M Morgan-Kiss
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA.
- Department of Microbiology, Miami University, 700 E High St., 212 Pearson Hall, Oxford, OH, 45056, USA.
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5
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Huang JJ, Cheung PCK. Cold stress treatment enhances production of metabolites and biodiesel feedstock in Porphyridium cruentum via adjustment of cell membrane fluidity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 780:146612. [PMID: 34030318 DOI: 10.1016/j.scitotenv.2021.146612] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/04/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Porphyridium cruentum, a cell-wall-free marine Rhodophyta microalga was cultured under a 5-day cold stress at 0 °C and 15 °C, after reaching the late logarithmic growth phase. Compared with the control at 25 °C, the cold stress treatment significantly (p < 0.05) increased the microalgal biomass (1.21-fold); the amounts of total polyunsaturated fatty acids (1.22-fold); individual fatty acids including linoleic acid (1.50-fold) and eicosatrienoic acid (1.85-fold), and a major carotenoid zeaxanthin (1.53-fold). Furthermore, production of biodiesel feedstock including total C16 + C18 fatty acids was significantly enhanced (p < 0.05) by 1.18-fold after the cold stress treatment. Principal component analysis further indicated that the biosynthetic pathways of fatty acids and carotenoids in this microalga were correlated with the cold stress treatment. These results suggested that P. cruentum had adjusted its cellular membrane fluidity via an 'arm-raising and screw-bolt fastening' mechanism mediated by the synergistic roles of cis-unsaturated fatty acids and carotenoids. The insight obtained from the responses to cold stress in P. cruentum could be a novel technological approach to enhance the production of microalgal metabolites and biodiesel feedstock.
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Affiliation(s)
- Jim Junhui Huang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, No. 100, Waihuan West Road, Guangzhou Higher Education Mega Center, Guangzhou 510006, Guangdong Province, People's Republic of China; Food and Nutritional Sciences Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong S.A.R., People's Republic of China; Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411, Republic of Singapore; Marine Biology Institute, Shantou University, Shantou 515063, Guangdong Province, People's Republic of China
| | - Peter Chi Keung Cheung
- Food and Nutritional Sciences Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong S.A.R., People's Republic of China.
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6
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Morales-Sánchez D, Schulze PSC, Kiron V, Wijffels RH. Temperature-Dependent Lipid Accumulation in the Polar Marine Microalga Chlamydomonas malina RCC2488. FRONTIERS IN PLANT SCIENCE 2020; 11:619064. [PMID: 33424911 PMCID: PMC7785989 DOI: 10.3389/fpls.2020.619064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/30/2020] [Indexed: 05/31/2023]
Abstract
The exploration of cold-adapted microalgae offers a wide range of biotechnological applications that can be used for human, animal, and environmental benefits in colder climates. Previously, when the polar marine microalga Chlamydomonas malina RCC2488 was cultivated under both nitrogen replete and depleted conditions at 8°C, it accumulated lipids and carbohydrates (up to 32 and 49%, respectively), while protein synthesis decreased (up to 15%). We hypothesized that the cultivation temperature had a more significant impact on lipid accumulation than the nitrogen availability in C. malina. Lipid accumulation was tested at three different temperatures, 4, 8, and 15°C, under nitrogen replete and depleted conditions. At 4°C under the nitrogen replete condition C. malina had the maximal biomass productivity (701.6 mg L-1 day-1). At this condition, protein content was higher than lipids and carbohydrates. The lipid fraction was mainly composed of polyunsaturated fatty acids (PUFA) in the polar lipid portion, achieving the highest PUFA productivity (122.5 mg L-1 day-1). At this temperature, under nitrogen deficiency, the accumulation of carbohydrates and neutral lipids was stimulated. At 8 and 15°C, under both nitrogen replete and depleted conditions, the lipid and carbohydrate content were higher than at 4°C, and the nitrogen stress condition did not affect the algal biochemical composition. These results suggest that C. malina is a polar marine microalga with a favorable growth temperature at 4°C and is stressed at temperatures ≥8°C, which directs the metabolism to the synthesis of lipids and carbohydrates. Nevertheless, C. malina RCC2488 is a microalga suitable for PUFA production at low temperatures with biomass productivities comparable with mesophilic strains.
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Affiliation(s)
- Daniela Morales-Sánchez
- The Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT – The Arctic University of Norway, Tromsø, Norway
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Peter S. C. Schulze
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
- Green Colab – Associação Oceano Verde, University of Algarve, Faro, Portugal
| | - Viswanath Kiron
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Rene H. Wijffels
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
- Bioprocess Engineering, AlgaePARC, Wageningen University, Wageningen, Netherlands
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7
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Morales-Sánchez D, Schulze PS, Kiron V, Wijffels RH. Production of carbohydrates, lipids and polyunsaturated fatty acids (PUFA) by the polar marine microalga Chlamydomonas malina RCC2488. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.102016] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Raymond JA, Morgan-Kiss R, Stahl-Rommel S. Glycerol Is an Osmoprotectant in Two Antarctic Chlamydomonas Species From an Ice-Covered Saline Lake and Is Synthesized by an Unusual Bidomain Enzyme. FRONTIERS IN PLANT SCIENCE 2020; 11:1259. [PMID: 32973829 PMCID: PMC7468427 DOI: 10.3389/fpls.2020.01259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
Glycerol, a compatible solute, has previously been found to act as an osmoprotectant in some marine Chlamydomonas species and several species of Dunaliella from hypersaline ponds. Recently, Chlamydomonas reinhardtii and Dunaliella salina were shown to make glycerol with an unusual bidomain enzyme, which appears to be unique to algae, that contains a phosphoserine phosphatase and glycerol-3-phosphate dehydrogenase. Here we report that two psychrophilic species of Chlamydomonas (C. spp. UWO241 and ICE-MDV) from Lake Bonney, Antarctica also produce high levels of glycerol to survive in the lake's saline waters. Glycerol concentration increased linearly with salinity and at 1.3 M NaCl, exceeded 400 mM in C. sp. UWO241, the more salt-tolerant strain. We also show that both species expressed several isoforms of the bidomain enzyme. An analysis of one of the isoforms of C. sp. UWO241 showed that it was strongly upregulated by NaCl and is thus the likely source of glycerol. These results reveal another adaptation of the Lake Bonney Chlamydomonas species that allow them to survive in an extreme polar environment.
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Affiliation(s)
- James A. Raymond
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, United States
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9
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Zhang Z, Qu C, Yao R, Nie Y, Xu C, Miao J, Zhong B. The Parallel Molecular Adaptations to the Antarctic Cold Environment in Two Psychrophilic Green Algae. Genome Biol Evol 2020; 11:1897-1908. [PMID: 31106822 PMCID: PMC6628873 DOI: 10.1093/gbe/evz104] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2019] [Indexed: 01/02/2023] Open
Abstract
Psychrophilic green algae from independent phylogenetic lines thrive in the polar extreme environments, but the hypothesis that their psychrophilic characteristics appeared through parallel routes of molecular evolution remains untested. The recent surge of transcriptome data enables large-scale evolutionary analyses to investigate the genetic basis for the adaptations to the Antarctic extreme environment, and the identification of the selective forces that drive molecular evolution is the foundation to understand the strategies of cold adaptation. Here, we conducted transcriptome sequencing of two Antarctic psychrophilic green algae (Chlamydomonas sp. ICE-L and Tetrabaena socialis) and performed positive selection and convergent substitution analyses to investigate their molecular convergence and adaptive strategies against extreme cold conditions. Our results revealed considerable shared positively selected genes and significant evidence of molecular convergence in two Antarctic psychrophilic algae. Significant evidence of positive selection and convergent substitution were detected in genes associated with photosynthetic machinery, multiple antioxidant systems, and several crucial translation elements in Antarctic psychrophilic algae. Our study reveals that the psychrophilic algae possess more stable photosynthetic apparatus and multiple protective mechanisms and provides new clues of parallel adaptive evolution in Antarctic psychrophilic green algae.
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Affiliation(s)
- Zhenhua Zhang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
| | - Changfeng Qu
- First Institute of Oceanography, Ministry of Natural Resources, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Ru Yao
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
| | - Yuan Nie
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
| | - Chenjie Xu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
| | - Jinlai Miao
- First Institute of Oceanography, Ministry of Natural Resources, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Bojian Zhong
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
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10
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Cook G, Teufel A, Kalra I, Li W, Wang X, Priscu J, Morgan-Kiss R. The Antarctic psychrophiles Chlamydomonas spp. UWO241 and ICE-MDV exhibit differential restructuring of photosystem I in response to iron. PHOTOSYNTHESIS RESEARCH 2019; 141:209-228. [PMID: 30729447 DOI: 10.1007/s11120-019-00621-0] [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: 07/17/2018] [Accepted: 01/25/2019] [Indexed: 06/09/2023]
Abstract
Chlamydomonas sp. UWO241 is a psychrophilic alga isolated from the deep photic zone of a perennially ice-covered Antarctic lake (east lobe Lake Bonney, ELB). Past studies have shown that C. sp. UWO241 exhibits constitutive downregulation of photosystem I (PSI) and high rates of PSI-associated cyclic electron flow (CEF). Iron levels in ELB are in the nanomolar range leading us to hypothesize that the unusual PSI phenotype of C. sp. UWO241 could be a response to chronic Fe-deficiency. We studied the impact of Fe availability in C. sp. UWO241, a mesophile, C. reinhardtii SAG11-32c, as well as a psychrophile isolated from the shallow photic zone of ELB, Chlamydomonas sp. ICE-MDV. Under Fe-deficiency, PsaA abundance and levels of photooxidizable P700 (ΔA820/A820) were reduced in both psychrophiles relative to the mesophile. Upon increasing Fe, C. sp. ICE-MDV and C. reinhardtii exhibited restoration of PSI function, while C. sp. UWO241 exhibited only moderate changes in PSI activity and lacked almost all LHCI proteins. Relative to Fe-excess conditions (200 µM Fe2+), C. sp. UWO241 grown in 18 µM Fe2+ exhibited downregulation of light harvesting and photosystem core proteins, as well as upregulation of a bestrophin-like anion channel protein and two CEF-associated proteins (NdsS, PGL1). Key enzymes of starch synthesis and shikimate biosynthesis were also upregulated. We conclude that in response to variable Fe availability, the psychrophile C. sp. UWO241 exhibits physiological plasticity which includes restructuring of the photochemical apparatus, increased PSI-associated CEF, and shifts in downstream carbon metabolism toward storage carbon and secondary stress metabolites.
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Affiliation(s)
- Greg Cook
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - Amber Teufel
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - Isha Kalra
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - Wei Li
- Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - Xin Wang
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - John Priscu
- Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - Rachael Morgan-Kiss
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA.
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11
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Chrismas NAM, Williamson CJ, Yallop ML, Anesio AM, Sánchez-Baracaldo P. Photoecology of the Antarctic cyanobacterium Leptolyngbya sp. BC1307 brought to light through community analysis, comparative genomics and in vitro photophysiology. Mol Ecol 2019; 27:5279-5293. [PMID: 30565777 DOI: 10.1111/mec.14953] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 10/11/2018] [Indexed: 12/17/2022]
Abstract
Cyanobacteria are important photoautotrophs in extreme environments such as the McMurdo Dry Valleys, Antarctica. Terrestrial Antarctic cyanobacteria experience constant darkness during the winter and constant light during the summer which influences the ability of these organisms to fix carbon over the course of an annual cycle. Here, we present a unique approach combining community structure, genomic and photophysiological analyses to understand adaptation to Antarctic light regimes in the cyanobacterium Leptolyngbya sp. BC1307. We show that Leptolyngbya sp. BC1307 belongs to a clade of cyanobacteria that inhabits near-surface environments in the McMurdo Dry Valleys. Genomic analyses reveal that, unlike close relatives, Leptolyngbya sp. BC1307 lacks the genes necessary for production of the pigment phycoerythrin and is incapable of complimentary chromatic acclimation, while containing several genes responsible for known photoprotective pigments. Photophysiology experiments confirmed Leptolyngbya sp. BC1307 to be tolerant of short-term exposure to high levels of photosynthetically active radiation, while sustained exposure reduced its capacity for photoprotection. As such, Leptolyngbya sp. BC1307 likely exploits low-light microenvironments within cyanobacterial mats in the McMurdo Dry Valleys.
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Affiliation(s)
- Nathan A M Chrismas
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, UK.,School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Christopher J Williamson
- School of Geographical Sciences, University of Bristol, Bristol, UK.,School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, UK
| | - Marian L Yallop
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, UK
| | - Alexandre M Anesio
- School of Geographical Sciences, University of Bristol, Bristol, UK.,Department of Environmental Sciences, Aarhus University, Roskilde, Denmark
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12
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Sun Y, Gao Y, Wang H, Yang X, Zhai H, Du Y. Stimulation of cyclic electron flow around PSI as a response to the combined stress of high light and high temperature in grape leaves. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:1038-1045. [PMID: 32291003 DOI: 10.1071/fp17269] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 04/06/2018] [Indexed: 05/05/2023]
Abstract
Changes in cyclic electron flow (CEF) around PSI activity after exposing grape (Vitis vinifera L.) seedling leaves to the combined stress of high temperature (HT) and high light (HL) were investigated. The PSII potential quantum efficiency (Fv/Fm) decreased significantly under exposure to HT, and this decrease was greater when HT was combined with HL, whereas the PSI activity maintained stable. HT enhanced CEF mediated by NAD(P)H dehydrogenase remarkably. Compared with the control leaves, the half-time of P700+ re-reduction decreased during the HT treatment; this decrease was even more pronounced under the combined stress, implying significantly enhanced CEF as a result of the treatment. However, the heat-induced increase in nonphotochemical quenching (NPQ) was greater under HL, accompanied by a greater enhancement in high-energy state quenching. These results suggest that the combined stress of HT and HL resulted in severe PSII photoinhibition, whereas CEF showed plasticity in its response to environmental stress and played an important role in PSII and PSI photoprotection through accelerating generation of the thylakoid proton gradient and the induction of NPQ.
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Affiliation(s)
- Yongjiang Sun
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, China
| | - Yulu Gao
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, China
| | - Hui Wang
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, China
| | - Xinghong Yang
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, China
| | - Heng Zhai
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, China
| | - Yuanpeng Du
- State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, China
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13
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Procházková L, Remias D, Řezanka T, Nedbalová L. Chloromonas nivalis subsp. tatrae, subsp. nov. (Chlamydomonadales, Chlorophyta): re-examination of a snow alga from the High Tatra Mountains (Slovakia). FOTTEA (PRAHA) 2018; 18:1-18. [PMID: 30976329 PMCID: PMC6456015 DOI: 10.5507/fot.2017.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Melting snow fields populated by aplanozygotes of the genus Chloromonas (Chlamydomonadales, Chlorophyta) are found in polar and alpine habitats. In the High Tatra Mountains (Slovakia), cells causing blooms of brownish-red snow designated as Scotiella tatrae kol turned out to be genetically (18S, ITS1 and ITS2 rDNA, rbcL) very closely related to Chloromonas nivalis (Chodat) Hoham et Mullet from the Austrian Alps. Therefore, Sc. tatrae is transferred into the latter taxon and reduced to a subspecies as Cr. nivalis subsp. tatrae. Both exhibit a similar photosynthetic performance, thrive in similar habitats at open sites above timberline, but differ in astaxanthin accumulation and number of aplanozygote cell wall flanges. In a field sample of Cr. nivalis subsp. tatrae, polyunsaturated fatty acids formed nearly 50 % of total lipids, dominating in phospholipids and glycolipids. Cr. nivalis subsp. tatrae represents likely a variation of a common cryoflora species with distinct morphology.
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Affiliation(s)
- Lenka Procházková
- Charles University, Faculty of Science, Department of Ecology, Viničná 7, CZ–128 44 Prague, Czech Republic
- Corresponding author
| | - Daniel Remias
- University of Applied Sciences Upper Austria, Stelzhamerstraße 23, A–4600 Wels, Austria
| | - Tomáš Řezanka
- Institute of Microbiology CAS, Vídeňská 1083, CZ–142 20 Prague, Czech Republic
| | - Linda Nedbalová
- Charles University, Faculty of Science, Department of Ecology, Viničná 7, CZ–128 44 Prague, Czech Republic
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14
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Applicability of Automated Cell Counter with a Chlorophyll Detector in Routine Management of Microalgae. Sci Rep 2018; 8:4967. [PMID: 29563559 PMCID: PMC5862891 DOI: 10.1038/s41598-018-23311-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/08/2018] [Indexed: 11/08/2022] Open
Abstract
Microalgae have attracted attention for several industrial applications, but all such applications demand culture quality because of their sensitivity to environmental changes. Although simplicity, speed, and accuracy are important to assess algal cultures, researchers have expended vast amounts of labor to monitor algal health using hemocytometry. Along with its user bias, quantifying the cell status aside from the cell density is not easy. This paper describes the easy and rapid evaluation of algal number and status using an image-based cell counter (Countess II FL; Thermo Fisher Scientific Inc.) with a fluorescent filter for chlorophyll. Unlike mammalian cultured cells larger than microalgae, it is not easy for a low-resolution camera alone to distinguish microalgae from grimy spots and microbubbles on counting plates. To assess this method's performance, freshwater/marine microalgae and environmental samples were evaluated using the instrument. Results reveal that an instrument with a fluorescence filter can distinguish microalgae from other particles more precisely than a device with no filter. Values obtained using the instrument were not significantly different from those obtained using hemocytometry. Moreover, the cell counter, but not hemocytometry, can qualify the algal status. Results demonstrate that this system, which has no user bias, can contribute to algal assessment.
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15
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Ivanov AG, Velitchkova MY, Allakhverdiev SI, Huner NPA. Heat stress-induced effects of photosystem I: an overview of structural and functional responses. PHOTOSYNTHESIS RESEARCH 2017; 133:17-30. [PMID: 28391379 DOI: 10.1007/s11120-017-0383-x] [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: 02/14/2017] [Accepted: 04/03/2017] [Indexed: 05/24/2023]
Abstract
Temperature is one of the main factors controlling the formation, development, and functional performance of the photosynthetic apparatus in all photoautotrophs (green plants, algae, and cyanobacteria) on Earth. The projected climate change scenarios predict increases in air temperature across Earth's biomes ranging from moderate (3-4 °C) to extreme (6-8 °C) by the year 2100 (IPCC in Climate change 2007: The physical science basis: summery for policymakers, IPCC WG1 Fourth Assessment Report 2007; Climate change 2014: Mitigation of Climate Change, IPCC WG3 Fifth Assessment Report 2014). In some areas, especially of the Northern hemisphere, even more extreme warm seasonal temperatures may occur, which possibly will cause significant negative effects on the development, growth, and yield of important agricultural crops. It is well documented that high temperatures can cause direct damages of the photosynthetic apparatus and photosystem II (PSII) is generally considered to be the primary target of heat-induced inactivation of photosynthesis. However, since photosystem I (PSI) is considered to determine the global amount of enthalpy in living systems (Nelson in Biochim Biophys Acta 1807:856-863, 2011; Photosynth Res 116:145-151, 2013), the effects of elevated temperatures on PSI might be of vital importance for regulating the photosynthetic response of all photoautotrophs in the changing environment. In this review, we summarize the experimental data that demonstrate the critical impact of heat-induced alterations on the structure, composition, and functional performance of PSI and their significant implications on photosynthesis under future climate change scenarios.
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Affiliation(s)
- Alexander G Ivanov
- Department of Biology, University of Western Ontario, 1151 Richmond Street N., London, ON, N6A 5B7, Canada.
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Bl. 21, 1113, Sofia, Bulgaria.
| | - Maya Y Velitchkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Bl. 21, 1113, Sofia, Bulgaria
| | - Suleyman I Allakhverdiev
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow, 142290, Russia
- Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119991, Russia
- Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Matbuat Avenue 2a, 1073, Baku, Azerbaijan
| | - Norman P A Huner
- Department of Biology, University of Western Ontario, 1151 Richmond Street N., London, ON, N6A 5B7, Canada
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16
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Shubin VV, Terekhova IV, Bolychevtseva YV, El-Mohsnawy E, Rögner M, Mäntele W, Kopczak MJ, Džafić E. Thermostability of photosystem I trimers and monomers from the cyanobacterium Thermosynechococcus elongatus. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 179:17-22. [PMID: 28213141 DOI: 10.1016/j.saa.2017.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/30/2017] [Accepted: 02/04/2017] [Indexed: 06/06/2023]
Abstract
The performance of solar energy conversion into alternative energy sources in artificial systems highly depends on the thermostability of photosystem I (PSI) complexes Terasaki et al. (2007), Iwuchukwu et al. (2010), Kothe et al. (2013) . To assess the thermostability of PSI complexes from the thermophilic cyanobacterium Thermosynechococcus elongatus heating induced perturbations on the level of secondary structure of the proteins were studied. Changes were monitored by Fourier transform infrared (FT-IR) spectra in the mid-IR region upon slow heating (1°C per minute) of samples in D2O phosphate buffer (pD 7.4) from 20°C to 100°C. These spectra showed distinct changes in the Amide I region of PSI complexes as a function of the rising temperature. Absorbance at the Amide I maximum of PSI monomers (centered around 1653cm-1), gradually dropped in two temperature intervals, i.e. 60-75 and 80-90°C. In contrast, absorbance at the Amide I maximum of PSI trimers (around 1656cm-1) dropped only in one temperature interval 80-95°C. The thermal profile of the spectral shift of α-helices bands in the region 1656-1642cm-1 confirms the same two temperature intervals for PSI monomers and only one interval for trimers. Apparently, the observed absorbance changes at the Amide I maximum during heating of PSI monomers and trimers are caused by deformation and unfolding of α-helices. The absence of absorbance changes in the interval of 20-65°C in PSI trimers is probably caused by a greater stability of protein secondary structure as compared to that in monomers. Upon heating above 80°C a large part of α-helices both in trimers and monomers converts to unordered and aggregated structures. Spectral changes of PSI trimers and monomers heated up to 100°C are irreversible due to protein denaturation and non-specific aggregation of complexes leading to new absorption bands at 1618-1620cm-1. We propose that monomers shield the denaturation sensitive sides at the monomer/monomer interface within a trimer, making the oligomeric structure more stable against thermal stress.
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Affiliation(s)
- Vladimir V Shubin
- Baсh Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld.2, Leninsky Ave., Moscow 119071, Russia
| | - Irina V Terekhova
- Baсh Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld.2, Leninsky Ave., Moscow 119071, Russia.
| | - Yulia V Bolychevtseva
- Baсh Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld.2, Leninsky Ave., Moscow 119071, Russia
| | - Eithar El-Mohsnawy
- Biochemie der Pflanzen, Ruhr Universität Bochum, 44780 Bochum, Germany; Botany Department, Faculty of Science, Kafrelsheikh University, 33511 Kafrelsheikh, Egypt
| | - Matthias Rögner
- Biochemie der Pflanzen, Ruhr Universität Bochum, 44780 Bochum, Germany
| | - Werner Mäntele
- Institut für Biophysik, J.W. Goethe Universität Frankfurt, 60438 Frankfurt, Germany
| | - Marta J Kopczak
- Biochemie der Pflanzen, Ruhr Universität Bochum, 44780 Bochum, Germany
| | - Enela Džafić
- Institut für Biophysik, J.W. Goethe Universität Frankfurt, 60438 Frankfurt, Germany
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17
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Identity, ecology and ecophysiology of planktic green algae dominating in ice-covered lakes on James Ross Island (northeastern Antarctic Peninsula). Extremophiles 2016; 21:187-200. [PMID: 27888351 DOI: 10.1007/s00792-016-0894-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/18/2016] [Indexed: 10/20/2022]
Abstract
The aim of this study was to assess the phylogenetic relationships, ecology and ecophysiological characteristics of the dominant planktic algae in ice-covered lakes on James Ross Island (northeastern Antarctic Peninsula). Phylogenetic analyses of 18S rDNA together with analysis of ITS2 rDNA secondary structure and cell morphology revealed that the two strains belong to one species of the genus Monoraphidium (Chlorophyta, Sphaeropleales, Selenastraceae) that should be described as new in future. Immotile green algae are thus apparently capable to become the dominant primary producer in the extreme environment of Antarctic lakes with extensive ice-cover. The strains grew in a wide temperature range, but the growth was inhibited at temperatures above 20 °C, indicating their adaptation to low temperature. Preferences for low irradiances reflected the light conditions in their original habitat. Together with relatively high growth rates (0.4-0.5 day-1) and unprecedently high content of polyunsaturated fatty acids (PUFA, more than 70% of total fatty acids), it makes these isolates interesting candidates for biotechnological applications.
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18
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Li T, Kirchhoff H, Gargouri M, Feng J, Cousins AB, Pienkos PT, Gang DR, Chen S. Assessment of photosynthesis regulation in mixotrophically cultured microalga Chlorella sorokiniana. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.07.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Chilling out: the evolution and diversification of psychrophilic algae with a focus on Chlamydomonadales. Polar Biol 2016. [DOI: 10.1007/s00300-016-2045-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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20
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Li H, Ahammed GJ, Zhou G, Xia X, Zhou J, Shi K, Yu J, Zhou Y. Unraveling Main Limiting Sites of Photosynthesis under Below- and Above-Ground Heat Stress in Cucumber and the Alleviatory Role of Luffa Rootstock. FRONTIERS IN PLANT SCIENCE 2016; 7:746. [PMID: 27313587 PMCID: PMC4889590 DOI: 10.3389/fpls.2016.00746] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 05/17/2016] [Indexed: 05/23/2023]
Abstract
Photosynthesis is one of the most thermo-sensitive processes in plants. Although the severity of heat stress could be attenuated by grafting approach, the primary damaged site of photosynthesis system under heat stress and the regulatory mechanism of rootstock-mediated heat tolerance are poorly understood. In the current study, cucumber plants grafted onto their own roots and heat-tolerant luffa roots were exposed to root-zone heat (25/40°C) and aerial heat (40/25°C) individually and in combination (40/40°C) to understand the response of photosynthetic process by investigating energy absorption and distribution, electron transport in photosystem (PS) II and I, and CO2 assimilation. According to the results, root-zone heat stress inhibited photosynthesis mainly through decreasing Rubisco activity, while aerial heat stress mainly through inhibiting PSII acceptor side. The imbalance in light absorption and utilization resulted in accumulation of reactive oxygen species that caused damage to photosynthetic apparatus, forming a vicious cycle. On the contrary, grafting cucumber onto heat-tolerant luffa rootstock alleviated heat-induced photosynthetic inhibition and oxidative stress by maintaining higher root vitality, HSP70 accumulation, and antioxidant potential.
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Affiliation(s)
- Hao Li
- Department of Horticulture, Zhejiang UniversityHangzhou, China
- College of Horticulture, Northwest A&F UniversityYangling, China
| | | | - Guona Zhou
- Department of Horticulture, Zhejiang UniversityHangzhou, China
| | - Xiaojian Xia
- Department of Horticulture, Zhejiang UniversityHangzhou, China
| | - Jie Zhou
- Department of Horticulture, Zhejiang UniversityHangzhou, China
| | - Kai Shi
- Department of Horticulture, Zhejiang UniversityHangzhou, China
| | - Jingquan Yu
- Department of Horticulture, Zhejiang UniversityHangzhou, China
| | - Yanhong Zhou
- Department of Horticulture, Zhejiang UniversityHangzhou, China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative BiologyHangzhou, China
- *Correspondence: Yanhong Zhou,
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21
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Han Y, Chen Z, Lv S, Ning K, Ji X, Liu X, Wang Q, Liu R, Fan S, Zhang X. MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce ( Lactuca sativa L.). FRONTIERS IN PLANT SCIENCE 2016; 7:1889. [PMID: 28018414 PMCID: PMC5159435 DOI: 10.3389/fpls.2016.01889] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 11/30/2016] [Indexed: 05/08/2023]
Abstract
Bolting in lettuce is promoted by high temperature and bolting resistance is of great economic importance for lettuce production. But how bolting is regulated at the molecular level remains elusive. Here, a bolting resistant line S24 and a bolting sensitive line S39 were selected for morphological, physiological, transcriptomic and proteomic comparisons. A total of 12204 genes were differentially expressed in S39 vs. S24. Line S39 was featured with larger leaves, higher levels of chlorophyll, soluble sugar, anthocyanin and auxin, consistent with its up-regulation of genes implicated in photosynthesis, oxidation-reduction and auxin actions. Proteomic analysis identified 30 differentially accumulated proteins in lines S39 and S24 upon heat treatment, and 19 out of the 30 genes showed differential expression in the RNA-Seq data. Exogenous gibberellins (GA) treatment promoted bolting in both S39 and S24, while 12 flowering promoting MADS-box genes were specifically induced in line S39, suggesting that although GA regulates bolting in lettuce, it may be the MADS-box genes, not GA, that plays a major role in differing the bolting resistance between these two lettuce lines.
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Affiliation(s)
- Yingyan Han
- Plant Science and Technology College, Beijing University of Agriculture/New Technological Laboratory in Agriculture Application in BeijingBeijing, China
| | - Zijing Chen
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Sciences, China Agricultural UniversityBeijing, China
| | - Shanshan Lv
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of SciencesShanghai, China
| | - Kang Ning
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Sciences, China Agricultural UniversityBeijing, China
| | - Xueliang Ji
- Plant Science and Technology College, Beijing University of Agriculture/New Technological Laboratory in Agriculture Application in BeijingBeijing, China
| | - Xueying Liu
- Plant Science and Technology College, Beijing University of Agriculture/New Technological Laboratory in Agriculture Application in BeijingBeijing, China
| | - Qian Wang
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Sciences, China Agricultural UniversityBeijing, China
| | - Renyi Liu
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of SciencesShanghai, China
| | - Shuangxi Fan
- Plant Science and Technology College, Beijing University of Agriculture/New Technological Laboratory in Agriculture Application in BeijingBeijing, China
- *Correspondence: Xiaolan Zhang, Shuangxi Fan,
| | - Xiaolan Zhang
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Sciences, China Agricultural UniversityBeijing, China
- *Correspondence: Xiaolan Zhang, Shuangxi Fan,
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22
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Nellaepalli S, Zsiros O, Tóth T, Yadavalli V, Garab G, Subramanyam R, Kovács L. Heat- and light-induced detachment of the light harvesting complex from isolated photosystem I supercomplexes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2014; 137:13-20. [PMID: 24874922 DOI: 10.1016/j.jphotobiol.2014.04.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 11/26/2022]
Abstract
In a previous study, using photosystem I enriched stroma thylakoid membrane vesicles, we have shown that the light harvesting complexes of this photosystem are prone to heat- and light-induced, thermo-optically driven detachment from the supercomplex [43]. We have also shown that the splitting of the supercomplex occurs in a gradual and specific manner, selectively affecting the different constituents of the antenna complexes. Here we further analyse these heat- and light-induced processes in isolated Photosystem I supercomplex using circular dichroism and 77K fluorescence emission spectroscopy and immuno blotting, and obtain further details on the sequence of events of the dissociation process as well as on the thermal stability of the different components. Our absorption and circular dichroism spectroscopy and immuno blotting data show that the dissociation of LHCI from PSI-LHCI supercomplex starts above 50°C. Also, the low temperature fluorescence emission spectra depicts decrease of maximum fluorescence emission at 730nm and an increase of the intensity at 685nm, and about 10nm blue-shifts, from 730 to 720nm and from 685 to 676nm, respectively, indicating the heat (50°C) induced detachment of LHCI from PSI core complexes. The reaction centre proteins are highly stable even at high temperatures. Lhca2 is more heat stable than the other light harvesting protein complexes of PSI, whereas Lhca4 and Lhca3 are rather labile. Combined heat and light treatments significantly enhances the disorganization of PSI-LHCI supercomplexes, indicating a thermo-optic mechanism, which might have significant role under combined heat and light stress conditions.
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Affiliation(s)
- Sreedhar Nellaepalli
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Ottó Zsiros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary
| | - Tünde Tóth
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary
| | - Venkateswarlu Yadavalli
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary
| | - Rajagopal Subramanyam
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India; Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - László Kovács
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary.
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23
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Shibata Y, Katoh W, Chiba T, Namie K, Ohnishi N, Minagawa J, Nakanishi H, Noguchi T, Fukumura H. Development of a novel cryogenic microscope with numerical aperture of 0.9 and its application to photosynthesis research. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:880-7. [PMID: 24650629 DOI: 10.1016/j.bbabio.2014.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 03/05/2014] [Accepted: 03/10/2014] [Indexed: 01/15/2023]
Abstract
A novel cryogenic optical-microscope system was developed in which the objective lens is set inside of the cryostat adiabatic vacuum space. Being isolated from the sample when it was cooled, the objective lens was maintained at room temperature during the cryogenic measurement. Therefore, the authors were able to use a color-aberration corrected objective lens with a numerical aperture of 0.9. The lens is equipped with an air vent for compatibility to the vacuum. The theoretically expected spatial resolutions of 0.39μm along the lateral direction and 1.3μm along the axial direction were achieved by the developed system. The system was applied to the observations of non-uniform distributions of the photosystems in the cells of a green alga, Chlamydomonas reinhardtii, at 94K. Gaussian decomposition analysis of the fluorescence spectra at all the pixels clearly demonstrated a non-uniform distribution of the two photosystems, as reflected in the variable ratios of the fluorescence intensities assigned to photosystem II and to those assigned to photosystem I. The system was also applied to the fluorescence spectroscopy of single isolated photosystem I complexes at 90K. The fluorescence, assigned to be emitted from a single photosystem I trimer, showed an intermittent fluctuation called blinking, which is typical for a fluorescence signal from a single molecule. The vibronic fluorescence bands at around 790nm were observed for single photosystem I trimers, suggesting that the color aberration is not serious up to the 800nm spectral region.
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Affiliation(s)
- Yutaka Shibata
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki aza Aoba, Aoba-ku, Sendai 980-8578, Japan.
| | - Wataru Katoh
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Tomofumi Chiba
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki aza Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Keisuke Namie
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki aza Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Norikazu Ohnishi
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Hanayo Nakanishi
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Hiroshi Fukumura
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki aza Aoba, Aoba-ku, Sendai 980-8578, Japan
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24
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Kong W, Li W, Romancova I, Prášil O, Morgan-Kiss RM. An integrated study of photochemical function and expression of a key photochemical gene (psbA) in photosynthetic communities of Lake Bonney (McMurdo Dry Valleys, Antarctica). FEMS Microbiol Ecol 2014; 89:293-302. [DOI: 10.1111/1574-6941.12296] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 01/31/2014] [Accepted: 01/31/2014] [Indexed: 11/27/2022] Open
Affiliation(s)
- Weidong Kong
- Department of Microbiology; Miami University; Oxford OH USA
| | - Wei Li
- Department of Microbiology; Miami University; Oxford OH USA
| | - Ingrid Romancova
- Laboratory of Photosynthesis; Algatech; Institute of Microbiology ASCR; Trebon Czech Republic
| | - Ondřej Prášil
- Laboratory of Photosynthesis; Algatech; Institute of Microbiology ASCR; Trebon Czech Republic
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25
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Lyon BR, Mock T. Polar Microalgae: New Approaches towards Understanding Adaptations to an Extreme and Changing Environment. BIOLOGY 2014; 3:56-80. [PMID: 24833335 PMCID: PMC4009763 DOI: 10.3390/biology3010056] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/22/2014] [Accepted: 01/24/2014] [Indexed: 02/02/2023]
Abstract
Polar Regions are unique and highly prolific ecosystems characterized by extreme environmental gradients. Photosynthetic autotrophs, the base of the food web, have had to adapt physiological mechanisms to maintain growth, reproduction and metabolic activity despite environmental conditions that would shut-down cellular processes in most organisms. High latitudes are characterized by temperatures below the freezing point, complete darkness in winter and continuous light and high UV in the summer. Additionally, sea-ice, an ecological niche exploited by microbes during the long winter seasons when the ocean and land freezes over, is characterized by large salinity fluctuations, limited gas exchange, and highly oxic conditions. The last decade has been an exciting period of insights into the molecular mechanisms behind adaptation of microalgae to the cryosphere facilitated by the advancement of new scientific tools, particularly "omics" techniques. We review recent insights derived from genomics, transcriptomics, and proteomics studies. Genes, proteins and pathways identified from these highly adaptable polar microbes have far-reaching biotechnological applications. Furthermore, they may provide insights into life outside this planet, as well as glimpses into the past. High latitude regions also have disproportionately large inputs into global biogeochemical cycles and are the region most sensitive to climate change.
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Affiliation(s)
- Barbara R Lyon
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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26
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An M, Mou S, Zhang X, Zheng Z, Ye N, Wang D, Zhang W, Miao J. Expression of fatty acid desaturase genes and fatty acid accumulation in Chlamydomonas sp. ICE-L under salt stress. BIORESOURCE TECHNOLOGY 2013; 149:77-83. [PMID: 24084208 DOI: 10.1016/j.biortech.2013.09.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 09/05/2013] [Accepted: 09/06/2013] [Indexed: 05/08/2023]
Abstract
The Antarctic ice microalgae Chlamydomonas sp. ICE-L which is highly resistant to salt stress holds promise in providing an alternative species for the production of microalgal oil. We studied the effects of the alga in confrontation with NaCl stress on the growth, oil yield and expression of fatty acid desaturase genes. The growth rate of Chlamydomonas sp. ICE-L decreased with the gradual increase in NaCl concentration. Interestingly, we found that the highest lipid content was achieved at 16‰ NaCl, reaching 23% (w/w). Meanwhile, the expression of Δ9ACPCiFAD increased rapidly while Δ12CiFAD, ω3CiFAD2 and Δ6CiFAD showed a delayed elevation in response to altered salt stress. C18:3 was the dominant PUFA, which account for about 75% TFA in Chlamydomonas sp. ICE-L. Under 96‰ and 128‰ NaCl stress, the content of C20:5 almost approached that of C18:3. In contrast, low salinity enhanced the dominance of C18:3 at the expense of C20:3 and C20:5.
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Affiliation(s)
- Meiling An
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao, China
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Gašparović B, Godrijan J, Frka S, Tomažić I, Penezić A, Marić D, Djakovac T, Ivančić I, Paliaga P, Lyons D, Precali R, Tepić N. Adaptation of marine plankton to environmental stress by glycolipid accumulation. MARINE ENVIRONMENTAL RESEARCH 2013; 92:120-132. [PMID: 24094892 DOI: 10.1016/j.marenvres.2013.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 09/09/2013] [Accepted: 09/12/2013] [Indexed: 06/02/2023]
Abstract
A systematic investigation of non-phosphorus containing glycolipids (GL) was conducted in the northern Adriatic Sea during two years at two stations with different nutrient loads. GL concentration varied both spatially and temporally, with values of 1.1-21.5 μg/L and 0.4-44.7 μg/L in the particulate and the dissolved fraction, respectively. The highest concentrations were measured during summer in surface waters and at the more oligotrophic station, where GL yields (% of total lipids) were often higher than 20% and 50% in the particulate and dissolved fractions, respectively. To obtain more insight into factors governing GL accumulation autotrophic plankton community structure (pico-, nano- and microplankton fractions), chlorophyll a, heterotrophic bacteria and nutrient concentrations were measured together with hydrographic parameters and sunlight intensity. During the investigated period smaller autotrophic plankton cells (pico- and followed by nanoplankton) prevailed in abundance over larger cells (microplankton), which were found in large numbers in freshened surface samples. Several major findings resulted from the study. Firstly, during PO4 limitation, particularly at the oligotrophic station, enhanced glycolipid instead of phospholipid accumulation takes place, representing an effective phosphate-conserving mechanism. Secondly, results suggest that at seawater temperatures >19 °C autotrophic plankton considerably accumulate GL, probably to achieve thermal stability. Thirdly, high sunlight intensities seem to influence increased GL accumulation; GL possibly plays a role in cell mechanisms that prevent/mitigate photooxidation. And finally, substantial accumulation of GL detected in the dissolved fraction could be related to the fact that GL do not contain biologically relevant elements, like phosphorus, which makes them an unattractive substrate for enzyme activity. Therefore, substantial portion of CO2 could be removed from the atmosphere in P-limited regions during summer via its capture by plankton and conversion to GL.
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Affiliation(s)
- Blaženka Gašparović
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia.
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Dolhi JM, Maxwell DP, Morgan-Kiss RM. The Antarctic Chlamydomonas raudensis: an emerging model for cold adaptation of photosynthesis. Extremophiles 2013; 17:711-22. [PMID: 23903324 DOI: 10.1007/s00792-013-0571-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022]
Abstract
Permanently cold habitats dominate our planet and psychrophilic microorganisms thrive in cold environments. Environmental adaptations unique to psychrophilic microorganisms have been thoroughly described; however, the vast majority of studies to date have focused on cold-adapted bacteria. The combination of low temperatures in the presence of light is one of the most damaging environmental stresses for a photosynthetic organism: in order to survive, photopsychrophiles (i.e. photosynthetic organisms adapted to low temperatures) balance temperature-independent reactions of light energy capture/transduction with downstream temperature-dependent metabolic processes such as carbon fixation. Here, we review research on photopsychrophiles with a focus on an emerging model organism, Chlamydomonas raudensis UWO241 (UWO241). UWO241 is a psychrophilic green algal species and is a member of the photosynthetic microbial eukaryote community that provides the majority of fixed carbon for ice-covered lake ecosystems located in the McMurdo Dry Valleys, Antarctica. The water column exerts a range of environmental stressors on the phytoplankton community that inhabits this aquatic ecosystem, including low temperatures, extreme shade of an unusual spectral range (blue-green), high salinity, nutrient deprivation and extremes in seasonal photoperiod. More than two decades of work on UWO241 have produced one of our most comprehensive views of environmental adaptation in a cold-adapted, photosynthetic microbial eukaryote.
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Affiliation(s)
- Jenna M Dolhi
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH 45056, USA
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An M, Mou S, Zhang X, Ye N, Zheng Z, Cao S, Xu D, Fan X, Wang Y, Miao J. Temperature regulates fatty acid desaturases at a transcriptional level and modulates the fatty acid profile in the Antarctic microalga Chlamydomonas sp. ICE-L. BIORESOURCE TECHNOLOGY 2013; 134:151-157. [PMID: 23500572 DOI: 10.1016/j.biortech.2013.01.142] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/23/2013] [Accepted: 01/24/2013] [Indexed: 06/01/2023]
Abstract
Chlamydomonas sp. ICE-L which can thrive in extreme environments of the Antarctic is a major biomass producer. The FAD genes in Chlamydomonas sp. ICE-L were obtained and sequence alignment showed that these genes are homologous to known FADs with conserved histidine motifs. In this study, we analyzed the transcription of five FADs and FA compositions at different temperatures. The results showed that the expressions of Δ9CiFAD, ω3CiFAD1 and ω3CiFAD2 were apparently up-regulated at 0°C, however, the up-regulation of Δ6CiFAD intensified with rising temperature. Meanwhile, analysis of the FA compositions showed that PUFAs were dominant compositions, accounting for more than 75% TFA in Chlamydomonas sp. ICE-L. Furthermore, PUFAs were significantly increased at 0 and 5°C, which may be attributed to higher proportions of C18:3 and C20:3. Moreover, PUFAs were significantly decreased at 15°C whereas SFAs were significantly increased.
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Affiliation(s)
- Meiling An
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao, China
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Raymond JA, Morgan-Kiss R. Separate origins of ice-binding proteins in antarctic chlamydomonas species. PLoS One 2013; 8:e59186. [PMID: 23536869 PMCID: PMC3594216 DOI: 10.1371/journal.pone.0059186] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 02/12/2013] [Indexed: 11/22/2022] Open
Abstract
The green alga Chlamydomonas raudensis is an important primary producer in a number of ice-covered lakes and ponds in Antarctica. A C. raudensis isolate (UWO241) from Lake Bonney in the McMurdo Dry Valleys, like many other Antarctic algae, was found to secrete ice-binding proteins (IBPs), which appear to be essential for survival in icy environments. The IBPs of several Antarctic algae (diatoms, a prymesiophyte, and a prasinophyte) are similar to each other (here designated as type I IBPs) and have been proposed to have bacterial origins. Other IBPs (type II IBPs) that bear no resemblance to type I IBPs, have been found in the Antarctic Chlamydomonas sp. CCMP681, a putative snow alga, raising the possibility that chlamydomonad IBPs developed separately from the IBPs of other algae. To test this idea, we obtained the IBP sequences of C. raudensis UWO241 by sequencing the transcriptome. A large number of transcripts revealed no sequences resembling type II IBPs. Instead, many isoforms resembling type I IBPs were found, and these most closely matched a hypothetical protein from the bacterium Stigmatella aurantiaca. The sequences were confirmed to encode IBPs by the activity of a recombinant protein and by the matching of predicted and observed isoelectric points and molecular weights. Furthermore, a mesophilic sister species, C. raudensis SAG49.72, showed no ice-binding activity or PCR products from UWO241 IBP primers. These results confirm that algal IBPs are required for survival in icy habitats and demonstrate that they have diverse origins that are unrelated to the taxonomic positions of the algae. Last, we show that the C. raudensis UWO241 IBPs can change the structure of ice in a way that could increase the survivability of cells trapped in the ice.
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Affiliation(s)
- James A Raymond
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, Nevada, United States of America.
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Barrett K, Jaward FM. A review of endosulfan, dichlorvos, diazinon, and diuron--pesticides used in Jamaica. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2012; 22:481-499. [PMID: 22720746 DOI: 10.1080/09603123.2012.667794] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The global agricultural sector is the primary user of pesticides, consuming more than three billion kilograms of pesticides annually. Although pesticides are beneficial in controlling the proliferation of pests, they have been associated with adverse human and ecological impacts. Approximately 87% of the annually imported pesticides in Jamaica are applied within agricultural or household settings. However, in Jamaica, the potential impact on humans, their property, and the environment is unknown, as the fate of many of the locally applied pesticides has not been established. This review discusses four pesticides extensively applied in agricultural practices in Jamaica - endosulfan, diazinon, diuron, and dichlorvos. The information presented is essential for the development of fate and transport models of these chemicals. Consequently, health and ecological impact assessments may be conducted from the generated models.
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Affiliation(s)
- Kayon Barrett
- Department of Environmental and Occupational Health, College of Public Health, University of South Florida, Tampa, FL, USA
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Possmayer M, Berardi G, Beall BFN, Trick CG, Hüner NPA, Maxwell DP. PLASTICITY OF THE PSYCHROPHILIC GREEN ALGA CHLAMYDOMONAS RAUDENSIS (UWO 241) (CHLOROPHYTA) TO SUPRAOPTIMAL TEMPERATURE STRESS(1). JOURNAL OF PHYCOLOGY 2011; 47:1098-1109. [PMID: 27020192 DOI: 10.1111/j.1529-8817.2011.01047.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Chlamydomonas raudensis H. Ettl (UWO 241) is a psychrophilic green alga endemic to Lake Bonney, Antarctica. The objective of this study was to investigate the response of UWO 241 to incubation at 24°C, a temperature close to optimum for related mesophilic species. Using chl a fluorescence analysis, shifting cells from a growth temperature of 10°C-24°C resulted in a decline in PSII photochemical efficiency with light energy being directed away from photochemistry and toward dissipative pathways. Using the SYTOX Green assay, it was determined that UWO 241 cells die when incubated at 24°C under growth irradiance with a half-time of 34.9 h. The role of light in cell death was minor as cell death occurred in darkness at 24°C with a half-time of 43.7 h. To examine the plasticity of UWO 241 to temperature stress, 10°C-grown cells were shifted to 24°C for 12 h and then returned to 10°C to recover. The 12 h incubation at 24°C, which resulted in <10% cell death, led to declines in both light-saturated rates of photosynthesis and respiration, PSII photochemistry and energy partitioning, and changes to transcript abundances-those associated with the light-harvesting protein of PSII and ferredoxin declining rapidly, whereas transcripts of specific heat-shock proteins (HSPs) increased. Within 24-48 h of being transferred back to 10°C, all parameters returned to levels occurring in 10°C-grown cells. This research shows, for the first time, that 24°C is a temperature that is lethal to UWO 241, and yet this organism displays considerable physiological and molecular plasticity.
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Affiliation(s)
- Marc Possmayer
- Department of Biology and The Biotron Experimental Climate Changes Research Centre, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Gino Berardi
- Department of Biology and The Biotron Experimental Climate Changes Research Centre, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Benjamin F N Beall
- Department of Biology and The Biotron Experimental Climate Changes Research Centre, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Charles G Trick
- Department of Biology and The Biotron Experimental Climate Changes Research Centre, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Norman P A Hüner
- Department of Biology and The Biotron Experimental Climate Changes Research Centre, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Denis P Maxwell
- Department of Biology and The Biotron Experimental Climate Changes Research Centre, The University of Western Ontario, London, Ontario, Canada N6A 5B7
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Savitch LV, Ivanov AG, Gudynaite-Savitch L, Huner NPA, Simmonds J. Cold Stress Effects on PSI Photochemistry in Zea mays: Differential Increase of FQR-Dependent Cyclic Electron Flow and Functional Implications. ACTA ACUST UNITED AC 2011; 52:1042-54. [DOI: 10.1093/pcp/pcr056] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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34
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The effect of prolonged darkness on the growth, recovery and survival of Antarctic sea ice diatoms. Polar Biol 2011. [DOI: 10.1007/s00300-011-0961-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Savitch LV, Ivanov AG, Krol M, Sprott DP, Oquist G, Huner NPA. Regulation of energy partitioning and alternative electron transport pathways during cold acclimation of lodgepole pine is oxygen dependent. PLANT & CELL PHYSIOLOGY 2010; 51:1555-70. [PMID: 20630988 DOI: 10.1093/pcp/pcq101] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Second year needles of Lodgepole pine (Pinus contorta L.) were exposed for 6 weeks to either simulated control summer ['summer'; 25 °C/250 photon flux denisty (PFD)], autumn ('autumn'; 15°C/250 PFD) or winter conditions ('winter'; 5 °C/250 PFD). We report that the proportion of linear electron transport utilized in carbon assimilation (ETR(CO2)) was 40% lower in both 'autumn' and 'winter' pine when compared with the 'summer' pine. In contrast, the proportion of excess photosynthetic linear electron transport (ETR(excess)) not used for carbon assimilation within the total ETR(Jf) increased by 30% in both 'autumn' and 'winter' pine. In 'autumn' pine acclimated to 15°C, the increased amounts of 'excess' electrons were directed equally to 21 kPa O2-dependent and 2 kPa O2-dependent alternative electron transport pathways and the fractions of excitation light energy utilized by PSII photochemistry (Φ(PSII)), thermally dissipated through Φ(NPQ) and dissipated by additional quenching mechanism(s) (Φ(f,D)) were similar to those in 'summer' pine. In contrast, in 'winter' needles acclimated to 5 °C, 60% of photosynthetically generated 'excess' electrons were utilized through the 2 kPa O2-dependent electron sink and only 15% by the photorespiratory (21 kPa O2) electron pathway. Needles exposed to 'winter' conditions led to a 3-fold lower Φ(PSII), only a marginal increase in Φ(NPQ) and a 2-fold higher Φ(f,D), which was O2 dependent compared with the 'summer' and 'autumn' pine. Our results demonstrate that the employment of a variety of alternative pathways for utilization of photosynthetically generated electrons by Lodgepole pine depends on the acclimation temperature. Furthermore, dissipation of excess light energy through constitutive non-photochemical quenching mechanisms is O2 dependent.
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Affiliation(s)
- Leonid V Savitch
- Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre, Ottawa, ON K1A0C6, Canada.
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Takizawa K, Takahashi S, Hüner NPA, Minagawa J. Salinity affects the photoacclimation of Chlamydomonas raudensis Ettl UWO241. PHOTOSYNTHESIS RESEARCH 2009; 99:195-203. [PMID: 19137412 DOI: 10.1007/s11120-008-9397-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 12/23/2008] [Indexed: 05/09/2023]
Abstract
Chlamydomonas raudensis Ettl UWO241, a natural variant of C. raudensis, is deficient in state transitions. Its habitat, the deepest layer of Lake Bonney in Antarctica, features low irradiance, low temperature, and high salinity. Although psychrophily and low-light acclimation of this green alga has been described, very little information is available on the effect of salinity. Here, we demonstrate that this psychrophile is halotolerant, not halophilic, and it shows energy redistribution between photosystem I and II based on energy spillover under low-salt conditions. Furthermore, we revealed that C. raudensis exhibits higher non-photochemical quenching in comparison with the mesophile Chlamydomonas reinhardtii, when grown with low-salt, which is due to the lower proton conductivity across the thylakoid membrane. Significance of the C. raudensis UWO241 traits found in the low salinity culture are implicated with their natural habitats, including the high salinity and extremely stable light environments.
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Affiliation(s)
- Kenji Takizawa
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
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37
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Morgan-Kiss RM, Ivanov AG, Modla S, Czymmek K, Hüner NPA, Priscu JC, Lisle JT, Hanson TE. Identity and physiology of a new psychrophilic eukaryotic green alga, Chlorella sp., strain BI, isolated from a transitory pond near Bratina Island, Antarctica. Extremophiles 2008; 12:701-11. [DOI: 10.1007/s00792-008-0176-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2008] [Accepted: 06/04/2008] [Indexed: 11/30/2022]
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38
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Gudynaite-Savitch L, Loiselay C, Savitch LV, Simmonds J, Kohalmi SE, Choquet Y, Hüner NPA. The small domain of cytochrome f from the psychrophile Chlamydomonas raudensis UWO 241 modulates the apparent molecular mass and decreases the accumulation of cytochrome f in the mesophile Chlamydomonas reinhardtii. Biochem Cell Biol 2008; 85:616-27. [PMID: 17901903 DOI: 10.1139/o07-066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cytochrome f from the psychrophile Chlamydomonas raudensis UWO 241 has a lower thermostability of its c-type heme and an apparent molecular mass that is 7 kDa lower than that of the model mesophilic green alga Chlamydomonas reinhardtii. We combined chloroplast transformation, site-directed mutagensis, and the creation of chimeric fusion constructs to assess the contribution of specific domains and (or) amino acids residues to the structure, stability, and accumulation of cytochrome f, as well as its function in photosynthetic intersystem electron transport. We demonstrate that differences in the amino acid sequence of the small domain and specific charged amino acids in the large domain of cytochrome f alter the physical properties of this protein but do not affect either the thermostability of the c-type heme, the apparent half-life of cytochrome f in the presence of the chloroplastic protein synthesis inhibitor chloramphenicol, or the capacity for photosynthetic intersystem electron transport, measured as e-/P700. However, pulse-labeling with [14C]acetate, combined with immunoblotting, indicated that the negative autoregulation of cytochrome f accumulation observed in mesophilic C. reinhardtii transformed with chimeric constructs from the psychrophile was likely the result of the defective association of the chimeric forms of cytochrome f with the other subunits of the cytochrome b6/f complex native to the C. reinhardtii wild type. These results are discussed in terms of the unique fatty acid composition of the thylakoid membranes of C. raudensis UWO 241 adapted to cold environments.
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Affiliation(s)
- Loreta Gudynaite-Savitch
- Department of Biology and The Biotron, University of Western Ontario, London, ON N6A 5B7, Canada.
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Varsano T, Wolf SG, Pick U. A Chlorophyll a/b-binding Protein Homolog That Is Induced by Iron Deficiency Is Associated with Enlarged Photosystem I Units in the Eucaryotic Alga Dunaliella salina. J Biol Chem 2006; 281:10305-15. [PMID: 16469742 DOI: 10.1074/jbc.m511057200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Adaptation of the halotolerant alga Dunaliella salina to iron deprivation involves extensive changes of chloroplast morphology, photosynthetic activities, and induction of a major 45-kDa chloroplast protein termed Tidi. Partial amino acid sequencing of proteolytic peptides suggested that Tidi resembles chlorophyll a/b-binding proteins which compose light-harvesting antenna complexes (LHC) (Varsano, T., Kaftan, D., and Pick, U. (2003) J. Plant Nutr. 26, 2197-2210). Here we show that Tidi shares the highest amino acid sequence similarity with light-harvesting I chlorophyll a/b-binding proteins from higher plants but has an extended proline-rich N-terminal domain. The accumulation of Tidi is reversed by iron supplementation, and its level is inversely correlated with photosystem I (PS-I) reaction center proteins. In native gel electrophoresis, Tidi co-migrates with enlarged PS-I-LHC-I super-complexes. Single particle electron microscopy analysis revealed that PS-I units from iron-deficient cells are larger (31 and 37 nm in diameter) than PS-I units from control cells (22 nm). The 77 K chlorophyll fluorescence emission spectra of isolated complexes suggest that the Tidi-LHC-I antenna are functionally coupled to the reaction centers of PS-I. These findings indicate that Tidi acts as an accessory antenna of PS-I. The enlargement of PS-I antenna in algae and in cyanobacteria under iron deprivation suggests a common limitation that requires rebalancing of the energy distribution between the two photosystems.
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MESH Headings
- Amino Acid Sequence
- Blotting, Northern
- Chlorophyll/chemistry
- Chlorophyll A
- Cloning, Molecular
- Cyanobacteria/metabolism
- Electrophoresis, Gel, Two-Dimensional
- Electrophoresis, Polyacrylamide Gel
- Eukaryota/metabolism
- Immunohistochemistry
- Iron/chemistry
- Iron/metabolism
- Iron Deficiencies
- Light
- Light-Harvesting Protein Complexes/metabolism
- Microscopy, Electron
- Molecular Sequence Data
- Photosystem I Protein Complex/chemistry
- Photosystem I Protein Complex/metabolism
- Proline/chemistry
- Protein Structure, Tertiary
- Proteins/chemistry
- RNA, Messenger/metabolism
- Sequence Analysis, Protein
- Sequence Homology, Amino Acid
- Spectrometry, Fluorescence
- Temperature
- Thylakoids/metabolism
- Time Factors
- Transcription, Genetic
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Affiliation(s)
- Tal Varsano
- Department of Biological Chemistry and Electron Microscopy Unit, Weizmann Institute of Science, Rehovot 76100, Israel
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40
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Morgan-Kiss RM, Priscu JC, Pocock T, Gudynaite-Savitch L, Huner NPA. Adaptation and acclimation of photosynthetic microorganisms to permanently cold environments. Microbiol Mol Biol Rev 2006; 70:222-52. [PMID: 16524924 PMCID: PMC1393254 DOI: 10.1128/mmbr.70.1.222-252.2006] [Citation(s) in RCA: 246] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Persistently cold environments constitute one of our world's largest ecosystems, and microorganisms dominate the biomass and metabolic activity in these extreme environments. The stress of low temperatures on life is exacerbated in organisms that rely on photoautrophic production of organic carbon and energy sources. Phototrophic organisms must coordinate temperature-independent reactions of light absorption and photochemistry with temperature-dependent processes of electron transport and utilization of energy sources through growth and metabolism. Despite this conundrum, phototrophic microorganisms thrive in all cold ecosystems described and (together with chemoautrophs) provide the base of autotrophic production in low-temperature food webs. Psychrophilic (organisms with a requirement for low growth temperatures) and psychrotolerant (organisms tolerant of low growth temperatures) photoautotrophs rely on low-temperature acclimative and adaptive strategies that have been described for other low-temperature-adapted heterotrophic organisms, such as cold-active proteins and maintenance of membrane fluidity. In addition, photoautrophic organisms possess other strategies to balance the absorption of light and the transduction of light energy to stored chemical energy products (NADPH and ATP) with downstream consumption of photosynthetically derived energy products at low temperatures. Lastly, differential adaptive and acclimative mechanisms exist in phototrophic microorganisms residing in low-temperature environments that are exposed to constant low-light environments versus high-light- and high-UV-exposed phototrophic assemblages.
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Affiliation(s)
- Rachael M Morgan-Kiss
- Graduate College of Marine Studies and Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.
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41
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Gudynaite-Savitch L, Gretes M, Morgan-Kiss RM, Savitch LV, Simmonds J, Kohalmi SE, Hüner NPA. Cytochrome f from the Antarctic psychrophile, Chlamydomonas raudensis UWO 241: structure, sequence, and complementation in the mesophile, Chlamydomonas reinhardtii. Mol Genet Genomics 2006; 275:387-98. [PMID: 16425016 DOI: 10.1007/s00438-005-0094-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Accepted: 12/16/2005] [Indexed: 10/25/2022]
Abstract
Although cytochrome f from the Antarctic psychrophile, Chlamydomonas raudensis UWO 241, exhibits a lower apparent molecular mass (34 kD) than that of the mesophile C. reinhardtii (41 kD) based on SDS-PAGE, both proteins are comparable in calculated molecular mass and show 79% identity in amino acid sequence. The difference in apparent molecular mass was maintained after expression of petA from both Chlamydomonas species in either E. coli or a C. reinhardtii DeltapetA mutant and after substitution of a unique third cysteine-292 to phenylalanine in the psychrophilic cytochrome f. Moreover, the heme of the psychrophilic form of cytochrome f was less stable upon heating than that of the mesophile. In contrast to C. raudensis, a C. reinhardtii DeltapetA mutant transformed with petA from C. raudensis exhibited the ability to undergo state transitions and a capacity for intersystem electron transport comparable to that of C. reinhardtii wild type. However, the C. reinhardtii petA transformants accumulated lower levels of cytochrome b ( 6 ) /f complexes and exhibited lower light saturated rates of O(2) evolution than C. reinhardtii wild type. We show that the presence of an altered form of cytochrome f in C. raudensis does not account for its inability to undergo state transitions or its impaired capacity for intersystem electron transport as previously suggested. A combined survey of the apparent molecular mass, thermal stability and amino acid sequences of cytochrome f from a broad range of mesophilic species shows unequivocally that the observed differences in cytochrome f structure are not related to psychrophilly. Thus, caution must be exercised in relating differences in amino acid sequence and thermal stability to adaptation to cold environments.
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Mock T, Hoch N. Long-term temperature acclimation of photosynthesis in steady-state cultures of the polar diatom Fragilariopsis cylindrus. PHOTOSYNTHESIS RESEARCH 2005; 85:307-17. [PMID: 16170633 DOI: 10.1007/s11120-005-5668-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Accepted: 04/14/2005] [Indexed: 05/04/2023]
Abstract
Cultures of the obligate psychrophilic diatom Fragilariopsis cylindrus (Grunow) were grown for 4 months under steady-state conditions at -1 degrees C and +7 degrees C (50 micromol photons m(-2) s(-1)) prior to measurements in order to investigate long-term acclimation of photosynthesis to both temperatures. No differences in maximum intrinsic quantum yield of PS II (F(V)/F(M)) and relative electron transport rates could be detected at either temperature after 4 months of acclimation. Measurements of photosynthesis (relative electron transport rates) vs. irradiance (P vs. E curves) revealed similar values for relative light utilization efficiency (alpha = 0.57 at -1 degrees C, alpha = 0.60 at +7 degrees C) but higher values for irradiance levels at which photosynthesis saturates (E(K)) at -1 degrees C and, therefore, higher maximum photosynthesis (P(MAX) = 54 (relative units) at -1 degrees C, P(MAX) = 49 at +7 degrees C). Nonphotochemical quenching (NPQ) measurements at 385 mumol photons m(-2) s(-1) indicated higher (37%) NPQ for diatoms grown at -1 degrees C compared to +7 degrees C, which was possibly related to a 2-fold increase in the concentration of the pigment diatoxanthin and a 9-fold up-regulation of a gene encoding a fucoxanthin chlorophyll a,c-binding protein. Expression of the D1 protein encoding gene psbA was ca. 1.5-fold up-regulated at -1 degrees C, whereas expression levels of other genes from Photosystem II (psbC, psbU, psbO), as well as rbcL, the gene encoding the Rubisco large subunit were similar at both temperatures. However, a 2-fold up-regulation of a plastid glyceraldehyde-P dehydrogenase at -1 degrees C indicated enhanced Calvin cycle activity. This study revealed for the first time that a polar diatom could efficiently acclimate photosynthesis over a wide range of polar temperatures given enough time. Acclimation of photosynthesis at -1 degrees C was probably regulated similarly to high light acclimation.
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Affiliation(s)
- Thomas Mock
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
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