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Ma X, Vanneste S, Chang J, Ambrosino L, Barry K, Bayer T, Bobrov AA, Boston L, Campbell JE, Chen H, Chiusano ML, Dattolo E, Grimwood J, He G, Jenkins J, Khachaturyan M, Marín-Guirao L, Mesterházy A, Muhd DD, Pazzaglia J, Plott C, Rajasekar S, Rombauts S, Ruocco M, Scott A, Tan MP, Van de Velde J, Vanholme B, Webber J, Wong LL, Yan M, Sung YY, Novikova P, Schmutz J, Reusch TBH, Procaccini G, Olsen JL, Van de Peer Y. Seagrass genomes reveal ancient polyploidy and adaptations to the marine environment. Nat Plants 2024; 10:240-255. [PMID: 38278954 PMCID: PMC7615686 DOI: 10.1038/s41477-023-01608-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 12/05/2023] [Indexed: 01/28/2024]
Abstract
We present chromosome-level genome assemblies from representative species of three independently evolved seagrass lineages: Posidonia oceanica, Cymodocea nodosa, Thalassia testudinum and Zostera marina. We also include a draft genome of Potamogeton acutifolius, belonging to a freshwater sister lineage to Zosteraceae. All seagrass species share an ancient whole-genome triplication, while additional whole-genome duplications were uncovered for C. nodosa, Z. marina and P. acutifolius. Comparative analysis of selected gene families suggests that the transition from submerged-freshwater to submerged-marine environments mainly involved fine-tuning of multiple processes (such as osmoregulation, salinity, light capture, carbon acquisition and temperature) that all had to happen in parallel, probably explaining why adaptation to a marine lifestyle has been exceedingly rare. Major gene losses related to stomata, volatiles, defence and lignification are probably a consequence of the return to the sea rather than the cause of it. These new genomes will accelerate functional studies and solutions, as continuing losses of the 'savannahs of the sea' are of major concern in times of climate change and loss of biodiversity.
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Affiliation(s)
- Xiao Ma
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Steffen Vanneste
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Jiyang Chang
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Luca Ambrosino
- Department of Research Infrastructure for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Kerrie Barry
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Till Bayer
- Marine Evolutionary Ecology, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Kiel, Germany
| | | | - LoriBeth Boston
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Justin E Campbell
- Coastlines and Oceans Division, Institute of Environment, Florida International University-Biscayne Bay Campus, Miami, FL, USA
| | - Hengchi Chen
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Maria Luisa Chiusano
- Department of Research Infrastructure for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Naples, Italy
- Department of Agricultural Sciences, University Federico II of Naples, Naples, Italy
| | - Emanuela Dattolo
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy
- National Biodiversity Future Centre, Palermo, Italy
| | - Jane Grimwood
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Guifen He
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jerry Jenkins
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Marina Khachaturyan
- Marine Evolutionary Ecology, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Kiel, Germany
- Institute of General Microbiology, University of Kiel, Kiel, Germany
| | - Lázaro Marín-Guirao
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy
- Seagrass Ecology Group, Oceanographic Center of Murcia, Spanish Institute of Oceanography (IEO-CSIC), Murcia, Spain
| | - Attila Mesterházy
- Centre for Ecological Research, Wetland Ecology Research Group, Debrecen, Hungary
| | - Danish-Daniel Muhd
- Institute of Climate Adaptation and Marine Biotechnology, Universiti Malaysia Terengganu, Terengganu, Malaysia
| | - Jessica Pazzaglia
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy
- National Biodiversity Future Centre, Palermo, Italy
| | - Chris Plott
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | | | - Stephane Rombauts
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Miriam Ruocco
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, Italy
- Fano Marine Center, Fano, Italy
| | - Alison Scott
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Köln, Germany
| | - Min Pau Tan
- Institute of Climate Adaptation and Marine Biotechnology, Universiti Malaysia Terengganu, Terengganu, Malaysia
| | - Jozefien Van de Velde
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Köln, Germany
| | - Bartel Vanholme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Jenell Webber
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Li Lian Wong
- Institute of Climate Adaptation and Marine Biotechnology, Universiti Malaysia Terengganu, Terengganu, Malaysia
| | - Mi Yan
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yeong Yik Sung
- Institute of Climate Adaptation and Marine Biotechnology, Universiti Malaysia Terengganu, Terengganu, Malaysia
| | - Polina Novikova
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Köln, Germany
| | - Jeremy Schmutz
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Thorsten B H Reusch
- Marine Evolutionary Ecology, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Kiel, Germany.
| | - Gabriele Procaccini
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy.
- National Biodiversity Future Centre, Palermo, Italy.
| | - Jeanine L Olsen
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands.
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
- Center for Plant Systems Biology, VIB, Ghent, Belgium.
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.
- College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing, China.
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2
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Graham OJ, Adamczyk EM, Schenk S, Dawkins P, Burke S, Chei E, Cisz K, Dayal S, Elstner J, Hausner ALP, Hughes T, Manglani O, McDonald M, Mikles C, Poslednik A, Vinton A, Wegener Parfrey L, Harvell CD. Manipulation of the seagrass-associated microbiome reduces disease severity. Environ Microbiol 2024; 26:e16582. [PMID: 38195072 DOI: 10.1111/1462-2920.16582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 12/27/2023] [Indexed: 01/11/2024]
Abstract
Host-associated microbes influence host health and function and can be a first line of defence against infections. While research increasingly shows that terrestrial plant microbiomes contribute to bacterial, fungal, and oomycete disease resistance, no comparable experimental work has investigated marine plant microbiomes or more diverse disease agents. We test the hypothesis that the eelgrass (Zostera marina) leaf microbiome increases resistance to seagrass wasting disease. From field eelgrass with paired diseased and asymptomatic tissue, 16S rRNA gene amplicon sequencing revealed that bacterial composition and richness varied markedly between diseased and asymptomatic tissue in one of the two years. This suggests that the influence of disease on eelgrass microbial communities may vary with environmental conditions. We next experimentally reduced the eelgrass microbiome with antibiotics and bleach, then inoculated plants with Labyrinthula zosterae, the causative agent of wasting disease. We detected significantly higher disease severity in eelgrass with a native microbiome than an experimentally reduced microbiome. Our results over multiple experiments do not support a protective role of the eelgrass microbiome against L. zosterae. Further studies of these marine host-microbe-pathogen relationships may continue to show new relationships between plant microbiomes and diseases.
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Affiliation(s)
- Olivia J Graham
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Emily M Adamczyk
- Department of Zoology and Biodiversity Research Centre, Unceded xʷməθkʷəy̓əm (Musqueam) Territory, University of British Columbia, Vancouver, British Columbia, Canada
| | - Siobhan Schenk
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Phoebe Dawkins
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Samantha Burke
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Emily Chei
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Kaitlyn Cisz
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Sukanya Dayal
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Jack Elstner
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | | | - Taylor Hughes
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Omisha Manglani
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Miles McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Chloe Mikles
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Anna Poslednik
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Audrey Vinton
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Laura Wegener Parfrey
- Department of Zoology and Biodiversity Research Centre, Unceded xʷməθkʷəy̓əm (Musqueam) Territory, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - C Drew Harvell
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
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3
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Zhang Y, Yue S, Liu M, Wang X, Xu S, Zhang X, Zhou Y. Combined transcriptome and proteome analysis reveal the key physiological processes in seed germination stimulated by decreased salinity in the seagrass Zostera marina L. BMC Plant Biol 2023; 23:605. [PMID: 38030999 PMCID: PMC10688091 DOI: 10.1186/s12870-023-04616-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/16/2023] [Indexed: 12/01/2023]
Abstract
BACKGROUND Zostera marina L., or eelgrass, is the most widespread seagrass species throughout the temperate northern hemisphere. Unlike the dry seeds of terrestrial plants, eelgrass seeds must survive in water, and salinity is the key factor influencing eelgrass seed germination. In the present study, transcriptome and proteome analysis were combined to investigate the mechanisms via which eelgrass seed germination was stimulated by low salinity, in addition to the dynamics of key metabolic pathways under germination. RESULTS According to the results, low salinity stimulated the activation of Ca2+ signaling and phosphatidylinositol signaling, and further initiated various germination-related physiological processes through the MAPK transduction cascade. Starch, lipids, and storage proteins were mobilized actively to provide the energy and material basis for germination; abscisic acid synthesis and signal transduction were inhibited whereas gibberellin synthesis and signal transduction were activated, weakening seed dormancy and preparing for germination; cell wall weakening and remodeling processes were activated to provide protection for cotyledon protrusion; in addition, multiple antioxidant systems were activated to alleviate oxidative stress generated during the germination process; ERF transcription factor has the highest number in both stages suggested an active role in eelgrass seed germination. CONCLUSION In summary, for the first time, the present study investigated the mechanisms by which eelgrass seed germination was stimulated by low salinity and analyzed the transcriptomic and proteomic features during eelgrass seed germination comprehensively. The results of the present study enhanced our understanding of seagrass seed germination, especially the molecular ecology of seagrass seeds.
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Affiliation(s)
- Yu Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Shidong Yue
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Mingjie Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Xinhua Wang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Shaochun Xu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Xiaomei Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Yi Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China.
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4
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Waters T, Gold Z, Obaza A, Ambrose RF, Eagle RA. Environmental DNA metabarcoding reveals distinct fish assemblages supported by seagrass (Zostera marina and Zostera pacifica) beds in different geographic settings in Southern California. PLoS One 2023; 18:e0286228. [PMID: 37796915 PMCID: PMC10553302 DOI: 10.1371/journal.pone.0286228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 09/18/2023] [Indexed: 10/07/2023] Open
Abstract
Seagrass beds are disappearing at a record pace despite their known value to our oceans and coastal communities. Simultaneously, our coastlines are under the constant pressure of climate change which is impacting their chemical, physical and biological characteristics. It is thus pertinent to evaluate and record habitat use so we can understand how these different environments contribute to local biodiversity. This study evaluates the assemblages of fish found at five Zostera beds in Southern California using environmental DNA (eDNA) metabarcoding. eDNA is a powerful biodiversity monitoring tool that offers key advantages to conventional monitoring. Results from our eDNA study found 78 species of fish that inhabit these five beds around Southern California representing embayment, open coastal mainland and open coastal island settings. While each bed had the same average number of species found throughout the year, the composition of these fish assemblages was strongly site dependent. There were 35 fish that were found at both open coast and embayment seagrass beds, while embayment seagrass sites had 20 unique fish and open coast sites had 23 unique fish. These results demonstrate that seagrass fish assemblages are heterogenous based on their geographic positioning and that marine managers must take this into account for holistic conservation and restoration efforts.
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Affiliation(s)
- Tanner Waters
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA, United States of America
- Center for Diverse Leadership in Science, University of California, Los Angeles, CA, United States of America
| | - Zachary Gold
- NOAA Pacific Marine Environmental Laboratory, Seattle, WA, United States of America
| | - Adam Obaza
- Paua Marine Research Group, Long Beach, CA, United States of America
| | - Richard F. Ambrose
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA, United States of America
- Department of Environmental Health Sciences, Jonathan and Karen Fielding School of Public Health, University of California, Los Angeles, CA, United States of America
| | - Robert A. Eagle
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA, United States of America
- Center for Diverse Leadership in Science, University of California, Los Angeles, CA, United States of America
- Atmospheric and Oceanic Sciences Department, University of California, Los Angeles, CA, United States of America
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5
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Yu L, Khachaturyan M, Matschiner M, Healey A, Bauer D, Cameron B, Cusson M, Emmett Duffy J, Joel Fodrie F, Gill D, Grimwood J, Hori M, Hovel K, Hughes AR, Jahnke M, Jenkins J, Keymanesh K, Kruschel C, Mamidi S, Menning DM, Moksnes PO, Nakaoka M, Pennacchio C, Reiss K, Rossi F, Ruesink JL, Schultz ST, Talbot S, Unsworth R, Ward DH, Dagan T, Schmutz J, Eisen JA, Stachowicz JJ, Van de Peer Y, Olsen JL, Reusch TBH. Ocean current patterns drive the worldwide colonization of eelgrass (Zostera marina). Nat Plants 2023; 9:1207-1220. [PMID: 37474781 PMCID: PMC10435387 DOI: 10.1038/s41477-023-01464-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/21/2023] [Indexed: 07/22/2023]
Abstract
Currents are unique drivers of oceanic phylogeography and thus determine the distribution of marine coastal species, along with past glaciations and sea-level changes. Here we reconstruct the worldwide colonization history of eelgrass (Zostera marina L.), the most widely distributed marine flowering plant or seagrass from its origin in the Northwest Pacific, based on nuclear and chloroplast genomes. We identified two divergent Pacific clades with evidence for admixture along the East Pacific coast. Two west-to-east (trans-Pacific) colonization events support the key role of the North Pacific Current. Time-calibrated nuclear and chloroplast phylogenies yielded concordant estimates of the arrival of Z. marina in the Atlantic through the Canadian Arctic, suggesting that eelgrass-based ecosystems, hotspots of biodiversity and carbon sequestration, have only been present there for ~243 ky (thousand years). Mediterranean populations were founded ~44 kya, while extant distributions along western and eastern Atlantic shores were founded at the end of the Last Glacial Maximum (~19 kya), with at least one major refuge being the North Carolina region. The recent colonization and five- to sevenfold lower genomic diversity of the Atlantic compared to the Pacific populations raises concern and opportunity about how Atlantic eelgrass might respond to rapidly warming coastal oceans.
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Affiliation(s)
- Lei Yu
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Marina Khachaturyan
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
- Institute of General Microbiology, Kiel University, Kiel, Germany
| | - Michael Matschiner
- Department of Paleontology and Museum, University of Zurich, Zurich, Switzerland
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Adam Healey
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Diane Bauer
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Brenda Cameron
- Department of Evolution and Ecology, University of California, Davis, CA, USA
| | - Mathieu Cusson
- Département des sciences fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Quebec, Canada
| | - J Emmett Duffy
- Tennenbaum Marine Observatories Network, Smithsonian Environmental Research Center, Edgewater, MD, USA
| | - F Joel Fodrie
- Institute of Marine Sciences (UNC-CH), Morehead City, NC, USA
| | - Diana Gill
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Jane Grimwood
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Masakazu Hori
- Japan Fisheries Research and Education Agency, Yokohama, Japan
| | - Kevin Hovel
- Department of Biology, San Diego State University, San Diego, CA, USA
| | | | - Marlene Jahnke
- Tjärnö Marine Laboratory, Department of Marine Sciences, University of Gothenburg, Strömstad, Sweden
| | - Jerry Jenkins
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Keykhosrow Keymanesh
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Sujan Mamidi
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | | | - Per-Olav Moksnes
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | | | - Christa Pennacchio
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Francesca Rossi
- Department of Integrative Marine Ecology (EMI), Stazione Zoologica Anton Dohrn-National Institute of Marine Biology, Ecology and Biotechnology, Genoa, Italy
| | | | | | - Sandra Talbot
- Far Northwestern Institute of Art and Science, Anchorage, AK, USA
| | - Richard Unsworth
- Department of Biosciences, Swansea University, Swansea, UK
- Project Seagrass, the Yard, Bridgend, UK
| | - David H Ward
- US Geological Survey, Alaska Science Center, Anchorage, AK, USA
| | - Tal Dagan
- Institute of General Microbiology, Kiel University, Kiel, Germany
| | - Jeremy Schmutz
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jonathan A Eisen
- Department of Evolution and Ecology, University of California, Davis, CA, USA
| | - John J Stachowicz
- Department of Evolution and Ecology, University of California, Davis, CA, USA
- Center for Population Biology, University of California, Davis, CA, USA
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent, Belgium
- Center for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing, China
- VIB-UGent Center for Plant Systems Biology, Gent, Belgium
| | - Jeanine L Olsen
- Groningen Institute for Evolutionary Life Sciences, Groningen, The Netherlands
| | - Thorsten B H Reusch
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
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6
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Chen J, Zang Y, Shang S, Yang Z, Liang S, Xue S, Wang Y, Tang X. Chloroplast genomic comparison provides insights into the evolution of seagrasses. BMC Plant Biol 2023; 23:104. [PMID: 36814193 PMCID: PMC9945681 DOI: 10.1186/s12870-023-04119-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Seagrasses are a polyphyletic group of monocotyledonous angiosperms that have evolved to live entirely submerged in marine waters. Thus, these species are ideal for studying plant adaptation to marine environments. Herein, we sequenced the chloroplast (cp) genomes of two seagrass species (Zostera muelleri and Halophila ovalis) and performed a comparative analysis of them with 10 previously published seagrasses, resulting in various novel findings. RESULTS The cp genomes of the seagrasses ranged in size from 143,877 bp (Zostera marina) to 178,261 bp (Thalassia hemprichii), and also varied in size among different families in the following order: Hydrocharitaceae > Cymodoceaceae > Ruppiaceae > Zosteraceae. The length differences between families were mainly related to the expansion and contraction of the IR region. In addition, we screened out 2,751 simple sequence repeats and 1,757 long repeat sequence types in the cp genome sequences of the 12 seagrass species, ultimately finding seven hot spots in coding regions. Interestingly, we found nine genes with positive selection sites, including two ATP subunit genes (atpA and atpF), three ribosome subunit genes (rps4, rps7, and rpl20), one photosystem subunit gene (psbH), and the ycf2, accD, and rbcL genes. These gene regions may have played critical roles in the adaptation of seagrasses to diverse environments. In addition, phylogenetic analysis strongly supported the division of the 12 seagrass species into four previously recognized major clades. Finally, the divergence time of the seagrasses inferred from the cp genome sequences was generally consistent with previous studies. CONCLUSIONS In this study, we compared chloroplast genomes from 12 seagrass species, covering the main phylogenetic clades. Our findings will provide valuable genetic data for research into the taxonomy, phylogeny, and species evolution of seagrasses.
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Affiliation(s)
- Jun Chen
- College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China
| | - Yu Zang
- Ministry of Natural Resources, Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Qingdao, Shandong, China
| | - Shuai Shang
- College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China
| | - Zhibo Yang
- College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China
| | - Shuo Liang
- College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China
| | - Song Xue
- College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China
| | - Ying Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, China.
| | - Xuexi Tang
- College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, China.
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7
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Chen S, Qiu G. Overexpression of Zostera japonica heat shock protein gene ZjHsp70 enhances the thermotolerance of transgenic Arabidopsis. Mol Biol Rep 2022; 49:6189-6197. [PMID: 35412177 DOI: 10.1007/s11033-022-07411-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/22/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Heat shock protein 70s (Hsp70s) are major members of the heat shock protein family and play a variety of roles to protect plants against stress. Plant Hsp70s are a conserved and widely expressed family of heat shock proteins. They have two main functional regions: N-terminal nucleic acid binding region and C-terminal substrate binding region. METHODS AND RESULTS In this study, we cloned the Hsp70 gene of Zostera japonica (ZjHsp70) based on the sequence obtained by transcriptome sequencing. The transcriptional levels of ZjHsp70 increased significantly at 1 h after heat treatment. ZjHsp70 was located in the cytoplasm and nucleus. The overexpression of ZjHsp70 in Arabidopsis resulted in increased heat tolerance, lower contents of malondialdehyde and higher antioxidant enzyme activity than in the wild type. ZjHsp70 may achieve this goal by maintaining highly active antioxidant enzymes. CONCLUSIONS We show that ZjHsp70 can improve plant heat tolerance by maintaining high antioxidant enzyme activity under high temperature stress. This study provided a basis to study the role of ZjHsp70 in thermotolerance in more detail.
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Affiliation(s)
- Siting Chen
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai, 536007, Guangxi, China.
| | - Guanglong Qiu
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai, 536007, Guangxi, China.
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8
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Pfeifer L, van Erven G, Sinclair EA, Duarte CM, Kabel MA, Classen B. Profiling the cell walls of seagrasses from A (Amphibolis) to Z (Zostera). BMC Plant Biol 2022; 22:63. [PMID: 35120456 PMCID: PMC8815203 DOI: 10.1186/s12870-022-03447-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND The polyphyletic group of seagrasses shows an evolutionary history from early monocotyledonous land plants to the marine environment. Seagrasses form important coastal ecosystems worldwide and large amounts of seagrass detritus washed on beaches might also be valuable bioeconomical resources. Despite this importance and potential, little is known about adaptation of these angiosperms to the marine environment and their cell walls. RESULTS We investigated polysaccharide composition of nine seagrass species from the Mediterranean, Red Sea and eastern Indian Ocean. Sequential extraction revealed a similar seagrass cell wall polysaccharide composition to terrestrial angiosperms: arabinogalactans, pectins and different hemicelluloses, especially xylans and/or xyloglucans. However, the pectic fractions were characterized by the monosaccharide apiose, suggesting unusual apiogalacturonans are a common feature of seagrass cell walls. Detailed analyses of four representative species identified differences between organs and species in their constituent monosaccharide composition and lignin content and structure. Rhizomes were richer in glucosyl units compared to leaves and roots. Enhalus had high apiosyl and arabinosyl abundance, while two Australian species of Amphibolis and Posidonia, were characterized by high amounts of xylosyl residues. Interestingly, the latter two species contained appreciable amounts of lignin, especially in roots and rhizomes whereas Zostera and Enhalus were lignin-free. Lignin structure in Amphibolis was characterized by a higher syringyl content compared to that of Posidonia. CONCLUSIONS Our investigations give a first comprehensive overview on cell wall composition across seagrass families, which will help understanding adaptation to a marine environment in the evolutionary context and evaluating the potential of seagrass in biorefinery incentives.
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Affiliation(s)
- Lukas Pfeifer
- Pharmaceutical Institute, Department of Pharmaceutical Biology, Christian-Albrechts-University of Kiel, Gutenbergstr. 76, 24118 Kiel, Germany
| | - Gijs van Erven
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Elizabeth A. Sinclair
- School of Biological Sciences and Oceans Institute, University of Western Australia, Crawley, WA Australia
| | - Carlos M. Duarte
- Red Sea Research Center (RSRC) and Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Mirjam A. Kabel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Birgit Classen
- Pharmaceutical Institute, Department of Pharmaceutical Biology, Christian-Albrechts-University of Kiel, Gutenbergstr. 76, 24118 Kiel, Germany
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9
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Shin C, Choi D, Hahn Y. Identification of the genome sequence of Zostera associated varicosavirus 1, a novel negative-sense RNA virus, in the common eelgrass (Zostera marina) transcriptome. Acta Virol 2021; 65:373-380. [PMID: 34796713 DOI: 10.4149/av_2021_404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Varicosaviruses (the genus Varicosavirus) are bipartite, negative-sense, single-stranded RNA viruses that infect plants. We analyzed a transcriptome dataset isolated from the common eelgrass (Zostera marina) and identified a novel varicosavirus named Zostera associated varicosavirus 1 (ZaVV1). The ZaVV1 genome consists of two genomic segments: RNA1 (6,632-nt) has an open reading frame (ORF) encoding a large multi-functional polymerase protein (L), while RNA2 (4,304-nt) has four ORFs: one for a nucleocapsid protein and three for proteins with unknown functions (P2, P3, and P4). Sequence comparison and phylogenetic analysis using L proteins showed that ZaVV1 is a novel member of the genus Varicosavirus of the family Rhabdoviridae. The conserved regulatory elements involved in transcription termination/polyadenylation and transcription initiation were identified in the ZaVV1 gene-junction regions with the consensus sequence 3'-UAUUAUUCUUUUUGCUCU-5' (in the negative-sense genome). The ZaVV1 genome sequence may be useful for studying the phylogenetic relationships of varicosaviruses and genome evolution of rhabdoviruses. Keywords: Zostera associated varicosavirus 1, Varicosavirus, Rhabdoviridae, common eelgrass, Zostera marina.
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10
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Zhang Y, Zhao P, Yue S, Liu M, Qiao Y, Xu S, Gu R, Zhang X, Zhou Y. New insights into physiological effects of anoxia under darkness on the iconic seagrass Zostera marina based on a combined analysis of transcriptomics and metabolomics. Sci Total Environ 2021; 768:144717. [PMID: 33736305 DOI: 10.1016/j.scitotenv.2020.144717] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
Coastal hypoxia/anoxia is a major emerging threat to global coastal ecosystems. Macroalgae blooms of tens of kilometers are often observed in open waters. These blooms not only cause a lack of oxygen, but also benthic light limitation. We explored the physiological responses of Zostera marina L. to anoxia under darkness. After exposing Z. marina to anoxia under darkness for 72 h, we measured the elongation of leaves and the decrease in maximal quantum yield of photosystem II (Fv/Fm), and investigated the transcriptomic and metabolomic responses to anoxic stress based on RNA-sequencing and liquid chromatography-mass spectrometry (LC-MS) technology. The results showed that anoxic stress significantly reduced the leaf Fv/Fm, and had a significant negative effect on the photosynthesis and growth of Z. marina. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of up-regulated differentially expressed genes (DEGs) showed that glycolysis was the most significant enrichment pathway (p < 0.001), and most of the important products in glycolysis were significantly up-regulated. This indicated that the glycolysis process of anaerobic respiration is promoted under anoxia. The metabolite results also showed that glyceraldehyde 3-phosphate in the glycolysis pathway was significantly up-regulated. Moreover, three genes encoding sucrose synthase (gene-ZOSMA_310G00150, gene-ZOSMA_81G00980, and gene-ZOSMA_8G00730) and one gene encoding alpha-amylase (gene-ZOSMA_95G00270) were significantly up-regulated, providing the sugar basis for the subsequent increase in glycolysis. Furthermore, gene-encoding oxoglutarate dehydrogenase, the rate-limiting step of the tricarboxylic acid (TCA) cycle, was significantly down-regulated, indicating that this cycle was inhibited under anoxia. Metabolomic results showed that L-tryptophan, L-phenylalanine, and DL-leucine were significantly up-regulated. Only significantly decreased glutamate and non-significantly decreased glutamine, substances consumed in alanine and γ-aminobutyric acid (GABA) shunt mechanisms, were detected in the leaves, while GABA and alanine were not detected. The results of this study show that anoxic stress induces a programmed transcriptomic and metabolomic response in seagrass, most likely reflecting a complex strategy of acclimation and adaptation in seagrass to resist anoxic stress.
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Affiliation(s)
- Yu Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Peng Zhao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China
| | - Shidong Yue
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mingjie Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yongliang Qiao
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Qingdao University of Science and Technology, Qingdao, 266000, China
| | - Shaochun Xu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruiting Gu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaomei Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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11
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Chen S, Qiu G. Heat-stress induced expression of stress-inducible nucleotide exchange factor Fes1 in seagrass Zostera japonica. Ecotoxicology 2020; 29:932-940. [PMID: 32162033 DOI: 10.1007/s10646-020-02185-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/24/2020] [Indexed: 06/10/2023]
Abstract
Seagrass meadows are among the four most productive marine natural ecosystems in the world. Zostera japonica (Z. japonica) is the most widely distributed species of seagrass in China. Nucleotide exchange factors (NEFs) promote the release of ADP during heat stress, accelerating the rate-limiting step of Heat shock protein 70 (Hsp70). Although NEFs play an important role in abiotic stress tolerance of plants, NEFs in seagrass have not been studied. In this study, we cloned Fes1 from Z. japonica (ZjFes1) by rapid amplification of the cDNA ends using RACE, and full length ZjFes1 was 1171 bp. It contained an 81 bp 5'-terminal untranslated region (UTR), 109 bp 3'-UTR and 981 bp open reading frame (ORF). The ORF (ZjFes1) was predicted to encode a polypeptide of 326 amino acids with theoretical molecular weight (MW) of 36.10 kDa and pI of 5.22. ZjFes1 shared 89% amino acid identity with Fes1 from Zostera marina (Z. marina). The transcriptional levels of ZjFes1 increased significantly 1 h after heat treatment. ZjFes1 was localized to the cytoplasm. Taken together, we found that ZjFes1 was a stress-inducible gene that may be involved in heat stress response. This study lays the foundation for further studies on the role of ZjFes1 in heat resistance.
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Affiliation(s)
- Siting Chen
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai, 536007, Guangxi, China.
| | - Guanglong Qiu
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai, 536007, Guangxi, China
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12
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Jahnke M, Moksnes PO, Olsen JL, Serra Serra N, Nilsson Jacobi M, Kuusemäe K, Corell H, Jonsson PR. Integrating genetics, biophysical, and demographic insights identifies critical sites for seagrass conservation. Ecol Appl 2020; 30:e02121. [PMID: 32159897 DOI: 10.1002/eap.2121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Abstract
The eelgrass Zostera marina is an important foundation species of coastal areas in the Northern Hemisphere, but is continuing to decline, despite management actions. The development of new management tools is therefore urgent in order to prioritize limited resources for protecting meadows most vulnerable to local extinctions and identifying most valuable present and historic meadows to protect and restore, respectively. We assessed 377 eelgrass meadows along the complex coastlines of two fjord regions on the Swedish west coast-one is currently healthy and the other is substantially degraded. Shoot dispersal for all meadows was assessed with Lagrangian biophysical modeling (scale: 100-1,000 m) and used for barrier analysis and clustering; a subset (n = 22) was also assessed with population genetic methods (20 microsatellites) including diversity, structure, and network connectivity. Both approaches were in very good agreement, resulting in seven subpopulation groupings or management units (MUs). The MUs correspond to a spatial scale appropriate for coastal management of "waterbodies" used in the European Water Framework Directive. Adding demographic modeling based on the genetic and biophysical data as a third approach, we are able to assess past, present, and future metapopulation dynamics to identify especially vulnerable and valuable meadows. In a further application, we show how the biophysical approach, using eigenvalue perturbation theory (EPT) and distribution records from the 1980s, can be used to identify lost meadows where restoration would best benefit the present metapopulation. The combination of methods, presented here as a toolbox, allows the assessment of different temporal and spatial scales at the same time, as well as ranking of specific meadows according to key genetic, demographic and ecological metrics. It could be applied to any species or region, and we exemplify its versatility as a management guide for eelgrass along the Swedish west coast.
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Affiliation(s)
- Marlene Jahnke
- Department of Marine Sciences - Tjärnö Marine Laboratory, University of Gothenburg, SE-45296, Strömstad, Sweden
| | - Per-Olav Moksnes
- Department of Marine Science, University of Gothenburg, SE-40530, Gothenburg, Sweden
| | - Jeanine L Olsen
- Groningen Institute for Evolutionary Life Sciences, Section: Ecology and Evolutionary Genomics in Nature (GREEN), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
| | - Núria Serra Serra
- Groningen Institute for Evolutionary Life Sciences, Section: Ecology and Evolutionary Genomics in Nature (GREEN), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
| | - Martin Nilsson Jacobi
- Complex Systems Group, Department of Energy and Environment, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | | | - Hanna Corell
- DHI Sverige, Svartmangatan 18, SE-111 29, Stockholm, Sweden
| | - Per R Jonsson
- Department of Marine Sciences - Tjärnö Marine Laboratory, University of Gothenburg, SE-45296, Strömstad, Sweden
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13
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Tan Y, Zhang QS, Zhao W, Liu Z, Ma MY, Zhong MY, Wang MX. The highly efficient NDH-dependent photosystem I cyclic electron flow pathway in the marine angiosperm Zostera marina. Photosynth Res 2020; 144:49-62. [PMID: 32152819 DOI: 10.1007/s11120-020-00732-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 03/03/2020] [Indexed: 05/13/2023]
Abstract
Zostera marina, a fully submerged marine angiosperm with a unique evolutionary history associated with its terrestrial origin, has distinct photochemical characteristics caused by its oxygen-evolving complex (OEC) being prone to deactivation in visible light. Based on the present phylogenetic analysis, the chloroplast NADPH dehydrogenase-like (NDH) complex was found to be completed in of Z. marina, unlike other marine plants, suggesting its crucial role. Thus, the responses of electron transport to irradiation were investigated through multiple chlorophyll fluorescence techniques and Western blot analysis. Moreover, the respective contribution of the two photosystem I cyclic electron flow (PSI-CEF) pathways to the generation of trans-thylakoid proton gradient (∆pH) was also examined using inhibitors. The contributions of the two PSI-CEF pathways to ∆pH were similar; furthermore, there was a trade-off between the two pathways under excess irradiation: the PGR5/L1-dependent PSI-CEF decreased gradually following its activation during the initial illumination, while NDH-dependent PSI-CEF was activated gradually with exposure duration. OEC inactivation was continuously under excess irradiation, which exhibits a positive linear correlation with the activation of NDH-dependent PSI-CEF. We suggest that PGR5/L1-dependent PSI-CEF was preferentially activated to handle the excess electron caused by the operation of OEC during the initial illumination. Subsequently, the increasing OEC inactivation with exposure duration resulted in a deficit of electrons. Limited electrons from PSI might preferentially synthesize NADPH, which could support the function of NDH-dependent PSI-CEF to generate ∆pH and ATP via reducing ferredoxin, thereby maintaining OEC stability.
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Affiliation(s)
- Ying Tan
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Quan Sheng Zhang
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China.
| | - Wei Zhao
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Zhe Liu
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Ming Yu Ma
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Ming Yu Zhong
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
| | - Meng Xin Wang
- Ocean School, Yantai University, Yantai, 264005, People's Republic of China
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14
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Abstract
Nucleotide exchange factors (NEFs) play an important role in plant abiotic stress response, but their characteristics and functions in seagrass have not been studied. Zostera japonica (Z. japonica) is one of the most widely distributed seagrass species in China and are distributed in subtropical and temperate coastal areas. Z. japonica is intertidal seagrass, which often undergoes heat stress during summer when the tide ebbs. Overexpression of ZjFes1 in Arabidopsis results in an increase in heat tolerance. We found that ZjFes1 associates with ZjHsp70 in vivo by yeast two-hybrid and bimolecular fluorescence complementarity (BiFC). Overexpression of ZjFes1 leads to selective reduction of Hsp70 transcription and an increase in Hsp101. In conclusion, our results suggest that ZjFes1 may be an active regulator of heat tolerance.
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Affiliation(s)
- Siting Chen
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai, China
- CONTACT Siting Chen Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai, Guangxi 536007, China
| | - Guanglong Qiu
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai, China
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15
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Shah Mohammadi N, Buapet P, Pernice M, Signal B, Kahlke T, Hardke L, Ralph PJ. Transcriptome profiling analysis of the seagrass, Zostera muelleri under copper stress. Mar Pollut Bull 2019; 149:110556. [PMID: 31546108 DOI: 10.1016/j.marpolbul.2019.110556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 08/09/2019] [Accepted: 08/27/2019] [Indexed: 06/10/2023]
Abstract
Copper (Cu) in an essential trace metal but it can also contaminate coastal waters at high concentrations mainly from agricultural run-off and mining activities which are detrimental to marine organisms including seagrasses. The molecular mechanisms driving Cu toxicity in seagrasses are not clearly understood yet. Here, we investigated the molecular responses of the Australian seagrass, Z. muelleri at the whole transcriptomic level after 7 days of exposure to 250 μg Cu L-1 and 500 μg Cu L-1. The leaf-specific whole transcriptome results showed a concentration-dependent disturbance in chloroplast function, regulatory stress responses and defense mechanisms. This study provided new insights into the responses of seagrasses to trace metal stress and reports possible candidate genes which can be considered as biomarkers to improve conservation and management of seagrass meadows.
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Affiliation(s)
- Nasim Shah Mohammadi
- University of Technology Sydney (UTS), Climate Change Cluster (C3), Broadway, Ultimo, NSW 2007, Australia
| | - Pimchanok Buapet
- Plant Physiology Laboratory, Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand; Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Mathieu Pernice
- University of Technology Sydney (UTS), Climate Change Cluster (C3), Broadway, Ultimo, NSW 2007, Australia.
| | - Bethany Signal
- University of Technology Sydney (UTS), Climate Change Cluster (C3), Broadway, Ultimo, NSW 2007, Australia
| | - Tim Kahlke
- University of Technology Sydney (UTS), Climate Change Cluster (C3), Broadway, Ultimo, NSW 2007, Australia
| | - Leo Hardke
- School of Earth and Environmental Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Peter J Ralph
- University of Technology Sydney (UTS), Climate Change Cluster (C3), Broadway, Ultimo, NSW 2007, Australia
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16
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Kim M, Pernice M, Watson-Lazowski A, Guagliardo P, Kilburn MR, Larkum AWD, Raven JA, Ralph PJ. Effect of reduced irradiance on 13C uptake, gene expression and protein activity of the seagrass Zostera muelleri. Mar Environ Res 2019; 149:80-89. [PMID: 31181418 DOI: 10.1016/j.marenvres.2019.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/30/2019] [Accepted: 06/05/2019] [Indexed: 06/09/2023]
Abstract
Photosynthesis in the seagrass Zostera muelleri remains poorly understood. We investigated the effect of reduced irradiance on the incorporation of 13C, gene expression of photosynthetic, photorespiratory and intermediates recycling genes as well as the enzymatic content and activity of Rubisco and PEPC within Z. muelleri. Following 48 h of reduced irradiance, we found that i) there was a ∼7 fold reduction in 13C incorporation in above ground tissue, ii) a significant down regulation of photosynthetic, photorespiratory and intermediates recycling genes and iii) no significant difference in enzyme activity and content. We propose that Z. muelleri is able to alter its physiology in order to reduce the amount of C lost through photorespiration to compensate for the reduced carbon assimilation as a result of reduced irradiance. In addition, the first estimated rate constant (Kcat) and maximum rates of carboxylation (Vcmax) of Rubisco is reported for the first time for Z. muelleri.
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Affiliation(s)
- Mikael Kim
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW, 2007, Australia
| | - Mathieu Pernice
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW, 2007, Australia.
| | - Alexander Watson-Lazowski
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, Australia; ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, Australia
| | - Paul Guagliardo
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth, WA, Australia
| | - Matt R Kilburn
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth, WA, Australia
| | - Anthony W D Larkum
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW, 2007, Australia
| | - John A Raven
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW, 2007, Australia; Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Peter J Ralph
- University of Technology Sydney, Climate Change Cluster, Ultimo, NSW, 2007, Australia
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Rubio L, Díaz-García J, Amorim-Silva V, Macho AP, Botella MA, Fernández JA. Molecular Characterization of ZosmaNRT2, the Putative Sodium Dependent High-Affinity Nitrate Transporter of Zostera marina L. Int J Mol Sci 2019; 20:ijms20153650. [PMID: 31357380 PMCID: PMC6695921 DOI: 10.3390/ijms20153650] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/19/2019] [Accepted: 07/24/2019] [Indexed: 01/24/2023] Open
Abstract
One of the most important adaptations of seagrasses during sea colonization was the capacity to grow at the low micromolar nitrate concentrations present in the sea. In contrast to terrestrial plants that use H+ symporters for high-affinity NO3− uptake, seagrasses such as Zostera marina L. use a Na+-dependent high-affinity nitrate transporter. Interestingly, in the Z. marina genome, only one gene (Zosma70g00300.1; NRT2.1) is annotated to this function. Analysis of this sequence predicts the presence of 12 transmembrane domains, including the MFS domains of the NNP transporter family and the “nitrate signature” that appears in all members of the NNP family. Phylogenetic analysis shows that this sequence is more related to NRT2.5 than to NRT2.1, sharing a common ancestor with both monocot and dicot plants. Heterologous expression of ZosmaNRT2-GFP together with the high-affinity nitrate transporter accessory protein ZosmaNAR2 (Zosma63g00220.1) in Nicotiana benthamiana leaves displayed four-fold higher fluorescence intensity than single expression of ZosmaNRT2-GFP suggesting the stabilization of NRT2 by NAR2. ZosmaNRT2-GFP signal was present on the Hechtian-strands in the plasmolyzed cells, pointing that ZosmaNRT2 is localized on the plasma membrane and that would be stabilized by ZosmaNAR2. Taken together, these results suggest that Zosma70g00300.1 would encode a high-affinity nitrate transporter located at the plasma membrane, equivalent to NRT2.5 transporters. These molecular data, together with our previous electrophysiological results support that ZosmaNRT2 would have evolved to use Na+ as a driving ion, which might be an essential adaptation of seagrasses to colonize marine environments.
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Affiliation(s)
- Lourdes Rubio
- Department of Botánica y Fisiología Vegetal, Campus de Teatinos, University of Málaga, 29071 Málaga, Spain.
| | - Jordi Díaz-García
- Department of Botánica y Fisiología Vegetal, Campus de Teatinos, University of Málaga, 29071 Málaga, Spain
| | - Vítor Amorim-Silva
- Department Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea ''La Mayora'' (IHSM-UMA-CSIC), University of Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - Alberto P Macho
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Miguel A Botella
- Department Biología Molecular y Bioquímica, Instituto de Hortofruticultura Subtropical y Mediterránea ''La Mayora'' (IHSM-UMA-CSIC), University of Málaga, Campus Teatinos, 29071 Málaga, Spain
| | - José A Fernández
- Department of Botánica y Fisiología Vegetal, Campus de Teatinos, University of Málaga, 29071 Málaga, Spain
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18
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Buapet P, Mohammadi NS, Pernice M, Kumar M, Kuzhiumparambil U, Ralph PJ. Excess copper promotes photoinhibition and modulates the expression of antioxidant-related genes in Zostera muelleri. Aquat Toxicol 2019; 207:91-100. [PMID: 30553148 DOI: 10.1016/j.aquatox.2018.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 12/03/2018] [Accepted: 12/04/2018] [Indexed: 05/08/2023]
Abstract
Copper (Cu) is an essential micronutrient for plants and as such is vital to many metabolic processes. Nevertheless, when present at elevated concentrations, Cu can exert toxic effects on plants by disrupting protein functions and promoting oxidative stress. Due to their proximity to the urbanised estuaries, seagrasses are vulnerable to chemical contamination via industrial runoff, waste discharges and leachates. Zostera muelleri is a common seagrass species that forms habitats in the intertidal areas along the temperate coast of Australia. Previous studies have shown the detrimental effects of Cu exposure on photosynthetic efficiency of Z. muelleri. The present study focuses on the impacts of sublethal Cu exposure on the physiological and molecular responses. By means of a single addition, plants were exposed to 250 and 500 μg Cu L-1 (corresponding to 3.9 and 7.8 μM, respectively) as well as uncontaminated artificial seawater (control) for 7 days. Chlorophyll fluorescence parameters, measured as the effective quantum yield (ϕPSII), the maximum quantum yield (Fv/Fm) and non-photochemical quenching (NPQ) were assessed daily, while Cu accumulation in leaf tissue, total reactive oxygen species (ROS) and the expression of genes involved in antioxidant activities and trace metal binding were determined after 1, 3 and 7 days of exposure. Z. muelleri accumulated Cu in the leaf tissue in a concentration-dependent manner and the bioaccumulation was saturated by day 3. Cu exposure resulted in an acute suppression of ϕPSII and Fv/Fm. These two parameters also showed a concentration- and time-dependent decline. NPQ increased sharply during the first few days before subsequently decreasing towards the end of the experiment. Cu accumulation induced oxidative stress in Z. muelleri as an elevated level of ROS was detected on day 7. Lower Cu concentration promoted an up-regulation of genes encoding Cu/Zn-superoxide dismutase (Cu/Zn-sod), ascorbate peroxidase (apx), catalase (cat) and glutathione peroxidase (gpx), whereas no significant change was detected with higher Cu concentration. Exposure to Cu at any concentration failed to induce regulation in the expression level of genes encoding metallothionein type 2 (mt2), metallothionein type 3 (mt3) and cytochrome c oxidase copper chaperone (cox17). It is concluded that chlorophyll fluorescence parameters provide timely probe of the status of photosynthetic machinery under Cu stress. In addition, when exposed to a moderate level of Cu, Z. muelleri mitigates any induced oxidative stress by up-regulating transcripts coding for antioxidant enzymes.
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Affiliation(s)
- Pimchanok Buapet
- Plant Physiology Laboratory, Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand; Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
| | | | - Mathieu Pernice
- Climate Change Cluster, University of Technology Sydney, NSW, Australia
| | - Manoj Kumar
- Climate Change Cluster, University of Technology Sydney, NSW, Australia
| | | | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, NSW, Australia
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19
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Berković B, Coelho N, Gouveia L, Serrão EA, Alberto F. Individual-based genetic analyses support asexual hydrochory dispersal in Zostera noltei. PLoS One 2018; 13:e0199275. [PMID: 30114218 PMCID: PMC6095491 DOI: 10.1371/journal.pone.0199275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/02/2018] [Indexed: 11/30/2022] Open
Abstract
Dispersal beyond the local patch in clonal plants was typically thought to result from sexual reproduction via seed dispersal. However, evidence for the separation, transport by water, and re-establishment of asexual propagules (asexual hydrochory) is mounting suggesting other important means of dispersal in aquatic plants. Using an unprecedented sampling size and microsatellite genetic identification, we describe the distribution of seagrass clones along tens of km within a coastal lagoon in Southern Portugal. Our spatially explicit individual-based sampling design covered 84 km2 and collected 3 185 Zostera noltei ramets from 803 sites. We estimated clone age, assuming rhizome elongation as the only mechanism of clone spread, and contrasted it with paleo-oceanographic sea level change. We also studied the association between a source of disturbance and the location of large clones. A total of 16 clones were sampled more than 10 times and the most abundant one was sampled 59 times. The largest distance between two samples from the same clone was 26.4 km and a total of 58 and 10 clones were sampled across more than 2 and 10 km, respectively. The number of extremely large clone sizes, and their old ages when assuming the rhizome elongation as the single causal mechanism, suggests other processes are behind the span of these clones. We discuss how the dispersal of vegetative fragments in a stepping-stone manner might have produced this pattern. We found higher probabilities to sample large clones away from the lagoon inlet, considered a source of disturbance. This study corroborates previous experiments on the success of transport and re-establishment of asexual fragments and supports the hypothesis that asexual hydrochory is responsible for the extent of these clones.
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Affiliation(s)
- Buga Berković
- Centro de Ciências do Mar, Universidade do Algarve, Faro, Portugal
| | - Nelson Coelho
- Centro de Ciências do Mar, Universidade do Algarve, Faro, Portugal
| | - Licínia Gouveia
- Centro de Ciências do Mar, Universidade do Algarve, Faro, Portugal
| | - Ester A. Serrão
- Centro de Ciências do Mar, Universidade do Algarve, Faro, Portugal
| | - Filipe Alberto
- Department of Biological Sciences, University of Wisconsin–Milwaukee, Milwaukee, Wisconsin, United States of America
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20
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Lee H, Golicz AA, Bayer PE, Severn-Ellis AA, Chan CKK, Batley J, Kendrick GA, Edwards D. Genomic comparison of two independent seagrass lineages reveals habitat-driven convergent evolution. J Exp Bot 2018; 69:3689-3702. [PMID: 29912443 PMCID: PMC6022596 DOI: 10.1093/jxb/ery147] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 04/12/2018] [Indexed: 05/06/2023]
Abstract
Seagrasses are marine angiosperms that live fully submerged in the sea. They evolved from land plant ancestors, with multiple species representing at least three independent return-to-the-sea events. This raises the question of whether these marine angiosperms followed the same adaptation pathway to allow them to live and reproduce under the hostile marine conditions. To compare the basis of marine adaptation between seagrass lineages, we generated genomic data for Halophila ovalis and compared this with recently published genomes for two members of Zosteraceae, as well as genomes of five non-marine plant species (Arabidopsis, Oryza sativa, Phoenix dactylifera, Musa acuminata, and Spirodela polyrhiza). Halophila and Zosteraceae represent two independent seagrass lineages separated by around 30 million years. Genes that were lost or conserved in both lineages were identified. All three species lost genes associated with ethylene and terpenoid biosynthesis, and retained genes related to salinity adaptation, such as those for osmoregulation. In contrast, the loss of the NADH dehydrogenase-like complex is unique to H. ovalis. Through comparison of two independent return-to-the-sea events, this study further describes marine adaptation characteristics common to seagrass families, identifies species-specific gene loss, and provides molecular evidence for convergent evolution in seagrass lineages.
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Affiliation(s)
- HueyTyng Lee
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD, Australia
- School of Biological Sciences, University of Western Australia, WA, Australia
| | - Agnieszka A Golicz
- Plant Molecular Biology and Biotechnology Laboratory, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Melbourne, VIC, Australia
| | - Philipp E Bayer
- School of Biological Sciences, University of Western Australia, WA, Australia
| | | | | | - Jacqueline Batley
- School of Biological Sciences, University of Western Australia, WA, Australia
| | - Gary A Kendrick
- School of Biological Sciences, University of Western Australia, WA, Australia
| | - David Edwards
- School of Biological Sciences, University of Western Australia, WA, Australia
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21
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Petersen G, Cuenca A, Zervas A, Ross GT, Graham SW, Barrett CF, Davis JI, Seberg O. Mitochondrial genome evolution in Alismatales: Size reduction and extensive loss of ribosomal protein genes. PLoS One 2017; 12:e0177606. [PMID: 28545148 PMCID: PMC5435185 DOI: 10.1371/journal.pone.0177606] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 04/28/2017] [Indexed: 11/18/2022] Open
Abstract
The order Alismatales is a hotspot for evolution of plant mitochondrial genomes characterized by remarkable differences in genome size, substitution rates, RNA editing, retrotranscription, gene loss and intron loss. Here we have sequenced the complete mitogenomes of Zostera marina and Stratiotes aloides, which together with previously sequenced mitogenomes from Butomus and Spirodela, provide new evolutionary evidence of genome size reduction, gene loss and transfer to the nucleus. The Zostera mitogenome includes a large portion of DNA transferred from the plastome, yet it is the smallest known mitogenome from a non-parasitic plant. Using a broad sample of the Alismatales, the evolutionary history of ribosomal protein gene loss is analyzed. In Zostera almost all ribosomal protein genes are lost from the mitogenome, but only some can be found in the nucleus.
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Affiliation(s)
- Gitte Petersen
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Argelia Cuenca
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Athanasios Zervas
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Gregory T. Ross
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
- UBC Botanical Garden & Centre for Plant Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sean W. Graham
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
- UBC Botanical Garden & Centre for Plant Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Craig F. Barrett
- L. H. Bailey Hortorium and Plant Biology Section, Cornell University, Ithaca, New York, United States of America
| | - Jerrold I. Davis
- L. H. Bailey Hortorium and Plant Biology Section, Cornell University, Ithaca, New York, United States of America
| | - Ole Seberg
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
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22
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Pernice M, Sinutok S, Sablok G, Commault AS, Schliep M, Macreadie PI, Rasheed MA, Ralph PJ. Molecular physiology reveals ammonium uptake and related gene expression in the seagrass Zostera muelleri. Mar Environ Res 2016; 122:126-134. [PMID: 28327303 DOI: 10.1016/j.marenvres.2016.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 10/18/2016] [Accepted: 10/18/2016] [Indexed: 05/24/2023]
Abstract
Seagrasses are important marine foundation species, which are presently threatened by coastal development and global change worldwide. The molecular mechanisms that drive seagrass responses to anthropogenic stresses, including elevated levels of nutrients such as ammonium, remains poorly understood. Despite the evidence that seagrasses can assimilate ammonium by using glutamine synthetase (GS)/glutamate synthase (glutamine-oxoglutarate amidotransferase or GOGAT) cycle, the regulation of this fundamental metabolic pathway has never been studied at the gene expression level in seagrasses so far. Here, we combine (i) reverse transcription quantitative real-time PCR (RT-qPCR) to measure expression of key genes involved in the GS/GOGAT cycle, and (ii) stable isotope labelling and mass spectrometry to investigate 15N-ammonium assimilation in the widespread Australian species Zostera muelleri subsp. capricorni (Z. muelleri). We demonstrate that exposure to a pulse of ammonium in seawater can induce changes in GS gene expression of Z. muelleri, and further correlate these changes in gene expression with 15N-ammonium uptake rate in above- and below-ground tissue.
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Affiliation(s)
- Mathieu Pernice
- Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia.
| | - Sutinee Sinutok
- Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia; Faculty of Environmental Management, Prince of Songkhla University, PO Box 50, Kor-Hong, Hatyai 90112, Thailand
| | - Gaurav Sablok
- Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
| | - Audrey S Commault
- Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
| | - Martin Schliep
- Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
| | - Peter I Macreadie
- Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia; School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Victoria 3125, Australia
| | - Michael A Rasheed
- TropWATER - Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, PO Box 6811, Cairns, Queensland 4870, Australia
| | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
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23
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Lee H, Golicz AA, Bayer PE, Jiao Y, Tang H, Paterson AH, Sablok G, Krishnaraj RR, Chan CKK, Batley J, Kendrick GA, Larkum AWD, Ralph PJ, Edwards D. The Genome of a Southern Hemisphere Seagrass Species (Zostera muelleri). Plant Physiol 2016; 172:272-83. [PMID: 27373688 PMCID: PMC5074622 DOI: 10.1104/pp.16.00868] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 06/28/2016] [Indexed: 05/19/2023]
Abstract
Seagrasses are marine angiosperms that evolved from land plants but returned to the sea around 140 million years ago during the early evolution of monocotyledonous plants. They successfully adapted to abiotic stresses associated with growth in the marine environment, and today, seagrasses are distributed in coastal waters worldwide. Seagrass meadows are an important oceanic carbon sink and provide food and breeding grounds for diverse marine species. Here, we report the assembly and characterization of the Zostera muelleri genome, a southern hemisphere temperate species. Multiple genes were lost or modified in Z. muelleri compared with terrestrial or floating aquatic plants that are associated with their adaptation to life in the ocean. These include genes for hormone biosynthesis and signaling and cell wall catabolism. There is evidence of whole-genome duplication in Z. muelleri; however, an ancient pan-commelinid duplication event is absent, highlighting the early divergence of this species from the main monocot lineages.
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Affiliation(s)
- HueyTyng Lee
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Agnieszka A Golicz
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Philipp E Bayer
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Yuannian Jiao
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Haibao Tang
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Andrew H Paterson
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Gaurav Sablok
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Rahul R Krishnaraj
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Chon-Kit Kenneth Chan
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Jacqueline Batley
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Gary A Kendrick
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Anthony W D Larkum
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - Peter J Ralph
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
| | - David Edwards
- School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland 4072, Australia (H.T.L., A.A.G., R.R.K., J.B., D.E.);School of Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (H.T.L., P.E.B., C.-K.K.C., J.B., G.A.K., D.E.);State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (Y.J.);Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602 (Y.J., A.H.P.);Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China (H.T.); andPlant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia (G.S., A.W.D.L., P.J.R.)
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Talbot SL, Sage GK, Rearick JR, Fowler MC, Muñiz-Salazar R, Baibak B, Wyllie-Echeverria S, Cabello-Pasini A, Ward DH. The Structure of Genetic Diversity in Eelgrass (Zostera marina L.) along the North Pacific and Bering Sea Coasts of Alaska. PLoS One 2016; 11:e0152701. [PMID: 27104836 PMCID: PMC4841600 DOI: 10.1371/journal.pone.0152701] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 03/17/2016] [Indexed: 11/25/2022] Open
Abstract
Eelgrass (Zostera marina) populations occupying coastal waters of Alaska are separated by a peninsula and island archipelago into two Large Marine Ecosystems (LMEs). From populations in both LMEs, we characterize genetic diversity, population structure, and polarity in gene flow using nuclear microsatellite fragment and chloroplast and nuclear sequence data. An inverse relationship between genetic diversity and latitude was observed (heterozygosity: R2 = 0.738, P < 0.001; allelic richness: R2 = 0.327, P = 0.047), as was significant genetic partitioning across most sampling sites (θ = 0.302, P < 0.0001). Variance in allele frequency was significantly partitioned by region only in cases when a population geographically in the Gulf of Alaska LME (Kinzarof Lagoon) was instead included with populations in the Eastern Bering Sea LME (θp = 0.128-0.172; P < 0.003), suggesting gene flow between the two LMEs in this region. Gene flow among locales was rarely symmetrical, with notable exceptions generally following net coastal ocean current direction. Genetic data failed to support recent proposals that multiple Zostera species (i.e. Z. japonica and Z. angustifolia) are codistributed with Z. marina in Alaska. Comparative analyses also failed to support the hypothesis that eelgrass populations in the North Atlantic derived from eelgrass retained in northeastern Pacific Last Glacial Maximum refugia. These data suggest northeastern Pacific populations are derived from populations expanding northward from temperate populations following climate amelioration at the terminus of the last Pleistocene glaciation.
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Affiliation(s)
- Sandra L. Talbot
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska, United States of America
| | - George K Sage
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska, United States of America
| | - Jolene R. Rearick
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska, United States of America
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Meg C. Fowler
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska, United States of America
| | - Raquel Muñiz-Salazar
- Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Ensenada, Baja California, Mexico
| | - Bethany Baibak
- Biological Sciences, Humboldt State University, Arcata, California, United States of America
| | - Sandy Wyllie-Echeverria
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
- Center for Marine and Environmental Studies, University of Virgin Islands, St. Thomas, Virgin Islands, United States of America
| | - Alejandro Cabello-Pasini
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, California, Mexico
| | - David H. Ward
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska, United States of America
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Abstract
Functional trait differences and genetic distance are increasingly used as metrics to predict the. outcome of species interactions and the maintenance of diversity. We apply these ideas to intraspecific diversity for the seagrass Zostera marina (eelgrass), by explicitly testing the influence of trait distance and genetic relatedness on the outcome of pairwise interactions among eelgrass genotypes. Increasing trait distance (but not relatedness) between eelgrass genotypes decreased the likelihood that both would persist over a year-long field experiment, contrary to our expectations based on niche partitioning. In plots in which one genotype excluded another, the biomass and growth of the remaining genotype increased with the trait distance and genetic relatedness of the initial pair, presumably due to a legacy of past interactions. Together these results suggest that sustained competition among functionally similar genotypes did not produce a clear winner, but rapid exclusion occurred among genotypes with distinct trait combinations. Borrowing from coexistence theory, we argue that fitness differences between genotypes with distinct traits overwhelmed any stabilizing effects of niche differentiation. Previously observed effects of eelgrass genetic diversity on performance may rely on nonadditive interactions among multiple genotypes or sufficient environmental heterogeneity to increase stabilizing forces and/or interactions.
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Golicz AA, Schliep M, Lee HT, Larkum AWD, Dolferus R, Batley J, Chan CKK, Sablok G, Ralph PJ, Edwards D. Genome-wide survey of the seagrass Zostera muelleri suggests modification of the ethylene signalling network. J Exp Bot 2015; 66:1489-98. [PMID: 25563969 PMCID: PMC4339605 DOI: 10.1093/jxb/eru510] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Seagrasses are flowering plants which grow fully submerged in the marine environment. They have evolved a range of adaptations to environmental challenges including light attenuation through water, the physical stress of wave action and tidal currents, high concentrations of salt, oxygen deficiency in marine sediment, and water-borne pollination. Although, seagrasses are a key stone species of the costal ecosystems, many questions regarding seagrass biology and evolution remain unanswered. Genome sequence data for the widespread Australian seagrass species Zostera muelleri were generated and the unassembled data were compared with the annotated genes of five sequenced plant species (Arabidopsis thaliana, Oryza sativa, Phoenix dactylifera, Musa acuminata, and Spirodela polyrhiza). Genes which are conserved between Z. muelleri and the five plant species were identified, together with genes that have been lost in Z. muelleri. The effect of gene loss on biological processes was assessed on the gene ontology classification level. Gene loss in Z. muelleri appears to influence some core biological processes such as ethylene biosynthesis. This study provides a foundation for further studies of seagrass evolution as well as the hormonal regulation of plant growth and development.
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Affiliation(s)
- Agnieszka A Golicz
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia Australian Centre for Plant Functional Genomics, School of Land, Crop and Food Sciences, University of Queensland, Brisbane, QLD 4067, Australia
| | - Martin Schliep
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Huey Tyng Lee
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia Australian Centre for Plant Functional Genomics, School of Land, Crop and Food Sciences, University of Queensland, Brisbane, QLD 4067, Australia
| | - Anthony W D Larkum
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Rudy Dolferus
- CSIRO Agriculture Flagship, GPO Box 1600, Canberra ACT 2601, Australia
| | - Jacqueline Batley
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia School of Plant Biology, University of Western Australia, WA, 6009, Australia
| | - Chon-Kit Kenneth Chan
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia School of Plant Biology, University of Western Australia, WA, 6009, Australia
| | - Gaurav Sablok
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Peter J Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - David Edwards
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia Australian Centre for Plant Functional Genomics, School of Land, Crop and Food Sciences, University of Queensland, Brisbane, QLD 4067, Australia School of Plant Biology, University of Western Australia, WA, 6009, Australia
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Cowart DA, Pinheiro M, Mouchel O, Maguer M, Grall J, Miné J, Arnaud-Haond S. Metabarcoding is powerful yet still blind: a comparative analysis of morphological and molecular surveys of seagrass communities. PLoS One 2015; 10:e0117562. [PMID: 25668035 PMCID: PMC4323199 DOI: 10.1371/journal.pone.0117562] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 12/27/2014] [Indexed: 11/26/2022] Open
Abstract
In the context of the sixth wave of extinction, reliable surveys of biodiversity are increasingly needed to infer the cause and consequences of species and community declines, identify early warning indicators of tipping points, and provide reliable impact assessments before engaging in activities with potential environmental hazards. DNA metabarcoding has emerged as having potential to provide speedy assessment of community structure from environmental samples. Here we tested the reliability of metabarcoding by comparing morphological and molecular inventories of invertebrate communities associated with seagrasses through estimates of alpha and beta diversity, as well as the identification of the most abundant taxa. Sediment samples were collected from six Zostera marina seagrass meadows across Brittany, France. Metabarcoding surveys were performed using both mitochondrial (Cytochrome Oxidase I) and nuclear (small subunit 18S ribosomal RNA) markers, and compared to morphological inventories compiled by a long-term benthic monitoring network. A sampling strategy was defined to enhance performance and accuracy of results by preventing the dominance of larger animals, boosting statistical support through replicates, and using two genes to compensate for taxonomic biases. Molecular barcodes proved powerful by revealing a remarkable level of diversity that vastly exceeded the morphological survey, while both surveys identified congruent differentiation of the meadows. However, despite the addition of individual barcodes of common species into taxonomic reference databases, the retrieval of only 36% of these species suggest that the remaining were either not present in the molecular samples or not detected by the molecular screening. This finding exemplifies the necessity of comprehensive and well-curated taxonomic reference libraries and multi-gene surveys. Overall, results offer methodological guidelines and support for metabarcoding as a powerful and repeatable method of characterizing communities, while also presenting suggestions for improvement, including implementation of pilot studies prior to performing full "blind" metabarcoding assessments to optimize sampling and amplification protocols.
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Affiliation(s)
- Dominique A. Cowart
- IFREMER (Institut Français de Recherche pour l’Exploitation de la MER), Unité Environnement Profond, Département des Ressources physiques et Ecosystèmes de Fond de mer (REM), B.P. 70, 29280, Plouzané, France
| | - Miguel Pinheiro
- University of St. Andrews, Medical and Biological Sciences Building, North Haugh, St. Andrews, Fife, KY16 9TF, United Kingdom
| | - Olivier Mouchel
- IFREMER (Institut Français de Recherche pour l’Exploitation de la MER), Unité Environnement Profond, Département des Ressources physiques et Ecosystèmes de Fond de mer (REM), B.P. 70, 29280, Plouzané, France
| | - Marion Maguer
- Institut Universitaire Européen de la Mer (IUEM), Technopôle Brest-Iroiserue Dumont d’Urville, 29280, Plouzané, France
| | - Jacques Grall
- Institut Universitaire Européen de la Mer (IUEM), Technopôle Brest-Iroiserue Dumont d’Urville, 29280, Plouzané, France
| | - Jacques Miné
- Total Exploration & Production, Direction HSE, 2 Place Jean Millier, 92078, Paris la Défense, France
| | - Sophie Arnaud-Haond
- IFREMER (Institut Français de Recherche pour l’Exploitation de la MER), Unité Environnement Profond, Département des Ressources physiques et Ecosystèmes de Fond de mer (REM), B.P. 70, 29280, Plouzané, France
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Kong F, Li H, Sun P, Zhou Y, Mao Y. De novo assembly and characterization of the transcriptome of seagrass Zostera marina using Illumina paired-end sequencing. PLoS One 2014; 9:e112245. [PMID: 25423588 PMCID: PMC4244107 DOI: 10.1371/journal.pone.0112245] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 10/10/2014] [Indexed: 01/15/2023] Open
Abstract
Background The seagrass Zostera marina is a monocotyledonous angiosperm belonging to a polyphyletic group of plants that can live submerged in marine habitats. Zostera marina L. is one of the most common seagrasses and is considered a cornerstone of marine plant molecular ecology research and comparative studies. However, the mechanisms underlying its adaptation to the marine environment still remain poorly understood due to limited transcriptomic and genomic data. Principal Findings Here we explored the transcriptome of Z. marina leaves under different environmental conditions using Illumina paired-end sequencing. Approximately 55 million sequencing reads were obtained, representing 58,457 transcripts that correspond to 24,216 unigenes. A total of 14,389 (59.41%) unigenes were annotated by blast searches against the NCBI non-redundant protein database. 45.18% and 46.91% of the unigenes had significant similarity with proteins in the Swiss-Prot database and Pfam database, respectively. Among these, 13,897 unigenes were assigned to 57 Gene Ontology (GO) terms and 4,745 unigenes were identified and mapped to 233 pathways via functional annotation against the Kyoto Encyclopedia of Genes and Genomes pathway database (KEGG). We compared the orthologous gene family of the Z. marina transcriptome to Oryza sativa and Pyropia yezoensis and 11,667 orthologous gene families are specific to Z. marina. Furthermore, we identified the photoreceptors sensing red/far-red light and blue light. Also, we identified a large number of genes that are involved in ion transporters and channels including Na+ efflux, K+ uptake, Cl− channels, and H+ pumping. Conclusions Our study contains an extensive sequencing and gene-annotation analysis of Z. marina. This information represents a genetic resource for the discovery of genes related to light sensing and salt tolerance in this species. Our transcriptome can be further utilized in future studies on molecular adaptation to abiotic stress in Z. marina.
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Affiliation(s)
- Fanna Kong
- Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
- * E-mail:
| | - Hong Li
- Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Peipei Sun
- Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yang Zhou
- Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yunxiang Mao
- Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
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29
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Brakel J, Werner FJ, Tams V, Reusch TBH, Bockelmann AC. Current European Labyrinthula zosterae are not virulent and modulate seagrass (Zostera marina) defense gene expression. PLoS One 2014; 9:e92448. [PMID: 24691450 PMCID: PMC3972160 DOI: 10.1371/journal.pone.0092448] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 02/21/2014] [Indexed: 01/06/2023] Open
Abstract
Pro- and eukaryotic microbes associated with multi-cellular organisms are receiving increasing attention as a driving factor in ecosystems. Endophytes in plants can change host performance by altering nutrient uptake, secondary metabolite production or defense mechanisms. Recent studies detected widespread prevalence of Labyrinthula zosterae in European Zostera marina meadows, a protist that allegedly caused a massive amphi-Atlantic seagrass die-off event in the 1930's, while showing only limited virulence today. As a limiting factor for pathogenicity, we investigated genotype × genotype interactions of host and pathogen from different regions (10-100 km-scale) through reciprocal infection. Although the endophyte rapidly infected Z. marina, we found little evidence that Z. marina was negatively impacted by L. zosterae. Instead Z. marina showed enhanced leaf growth and kept endophyte abundance low. Moreover, we found almost no interaction of protist × eelgrass-origin on different parameters of L. zosterae virulence/Z. marina performance, and also no increase in mortality after experimental infection. In a target gene approach, we identified a significant down-regulation in the expression of 6/11 genes from the defense cascade of Z. marina after real-time quantitative PCR, revealing strong immune modulation of the host's defense by a potential parasite for the first time in a marine plant. Nevertheless, one gene involved in phenol synthesis was strongly up-regulated, indicating that Z. marina plants were probably able to control the level of infection. There was no change in expression in a general stress indicator gene (HSP70). Mean L. zosterae abundances decreased below 10% after 16 days of experimental runtime. We conclude that under non-stress conditions L. zosterae infection in the study region is not associated with substantial virulence.
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Affiliation(s)
- Janina Brakel
- Experimental Ecology – Food webs, Geomar Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Franziska Julie Werner
- Experimental Ecology – Food webs, Geomar Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Verena Tams
- Evolutionary Ecology of Marine Fishes, Geomar Helmholtz Centre for Ocean Research Kiel, Germany
| | - Thorsten B. H. Reusch
- Evolutionary Ecology of Marine Fishes, Geomar Helmholtz Centre for Ocean Research Kiel, Germany
| | - Anna-Christina Bockelmann
- Experimental Ecology – Food webs, Geomar Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
- * E-mail:
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30
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Ort BS, Cohen CS, Boyer KE, Reynolds LK, Tam SM, Wyllie-Echeverria S. Conservation of eelgrass (Zostera marina) genetic diversity in a mesocosm-based restoration experiment. PLoS One 2014; 9:e89316. [PMID: 24586683 PMCID: PMC3931754 DOI: 10.1371/journal.pone.0089316] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 01/21/2014] [Indexed: 11/18/2022] Open
Abstract
Eelgrass (Zostera marina) forms the foundation of an important shallow coastal community in protected estuaries and bays. Widespread population declines have stimulated restoration efforts, but these have often overlooked the importance of maintaining the evolutionary potential of restored populations by minimizing the reduction in genetic diversity that typically accompanies restoration. In an experiment simulating a small-scale restoration, we tested the effectiveness of a buoy-deployed seeding technique to maintain genetic diversity comparable to the seed source populations. Seeds from three extant source populations in San Francisco Bay were introduced into eighteen flow-through baywater mesocosms. Following seedling establishment, we used seven polymorphic microsatellite loci to compare genetic diversity indices from 128 shoots to those found in the source populations. Importantly, allelic richness and expected heterozygosity were not significantly reduced in the mesocosms, which also preserved the strong population differentiation present among source populations. However, the inbreeding coefficient FIS was elevated in two of the three sets of mesocosms when they were grouped according to their source population. This is probably a Wahlund effect from confining all half-siblings within each spathe to a single mesocosm, elevating FIS when the mesocosms were considered together. The conservation of most alleles and preservation of expected heterozygosity suggests that this seeding technique is an improvement over whole-shoot transplantation in the conservation of genetic diversity in eelgrass restoration efforts.
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Affiliation(s)
- Brian S. Ort
- Romberg Tiburon Center for Environmental Studies, Department of Biology, San Francisco State University, Tiburon, California, United States of America
- * E-mail:
| | - C. Sarah Cohen
- Romberg Tiburon Center for Environmental Studies, Department of Biology, San Francisco State University, Tiburon, California, United States of America
| | - Katharyn E. Boyer
- Romberg Tiburon Center for Environmental Studies, Department of Biology, San Francisco State University, Tiburon, California, United States of America
| | - Laura K. Reynolds
- Romberg Tiburon Center for Environmental Studies, Department of Biology, San Francisco State University, Tiburon, California, United States of America
| | - Sheh May Tam
- Romberg Tiburon Center for Environmental Studies, Department of Biology, San Francisco State University, Tiburon, California, United States of America
| | - Sandy Wyllie-Echeverria
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
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Massa SI, Paulino CM, Serrão EA, Duarte CM, Arnaud-Haond S. Entangled effects of allelic and clonal (genotypic) richness in the resistance and resilience of experimental populations of the seagrass Zostera noltii to diatom invasion. BMC Ecol 2013; 13:39. [PMID: 24152760 PMCID: PMC3818440 DOI: 10.1186/1472-6785-13-39] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 10/14/2013] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The relationship between species diversity and components of ecosystem stability has been extensively studied, whilst the influence of the genetic component of biodiversity remains poorly understood. Here we manipulated both genotypic and allelic richness of the seagrass Zostera noltii, in order to explore their respective influences on the resistance of the experimental population to stress. Thus far intra-specific diversity was seldom taken into account in management plans, and restoration actions showed very low success. Information is therefore needed to understand the factors affecting resistance and resilience of populations. RESULTS Our results show a positive influence of both allelic and genotypic richness on the resistance of meadows to environmental perturbations. They also show that at the low genotypic (i.e. clonal) richness levels used in prior experimental approaches, the effects of genotypic and allelic richness could not be disentangled and allelic richness was a likely hidden treatment explaining at least part of the effects hitherto attributed to genotypic richness. CONCLUSIONS Altogether, these results emphasize the need to acknowledge and take into account the interdependency of both genotypic and allelic richness in experimental designs attempting to estimate their importance alone or in combination. A positive influence of allelic richness on resistance to perturbations, and of allelic richness combined with genotypic richness on the recovery (resilience) of the experimental populations is supported by differential mortality. These results, on the key species structuring of one of the most threatened coastal ecosystem worldwide, seagrass meadows, support the need to better take into account the distinct compartments of clonal and genetic diversity in management strategies, and in possible restoration plans in the future.
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Abstract
Disturbance and habitat destruction due to human activities is a pervasive problem in near-shore marine ecosystems, and restoration is often used to mitigate losses. A common metric used to evaluate the success of restoration is the return of ecosystem services. Previous research has shown that biodiversity, including genetic diversity, is positively associated with the provision of ecosystem services. We conducted a restoration experiment using sources, techniques, and sites similar to actual large-scale seagrass restoration projects and demonstrated that a small increase in genetic diversity enhanced ecosystem services (invertebrate habitat, increased primary productivity, and nutrient retention). In our experiment, plots with elevated genetic diversity had plants that survived longer, increased in density more quickly, and provided more ecosystem services (invertebrate habitat, increased primary productivity, and nutrient retention). We used the number of alleles per locus as a measure of genetic diversity, which, unlike clonal diversity used in earlier research, can be applied to any organism. Additionally, unlike previous studies where positive impacts of diversity occurred only after a large disturbance, this study assessed the importance of diversity in response to potential environmental stresses (high temperature, low light) along a water-depth gradient. We found a positive impact of diversity along the entire depth gradient. Taken together, these results suggest that ecosystem restoration will significantly benefit from obtaining sources (transplants or seeds) with high genetic diversity and from restoration techniques that can maintain that genetic diversity.
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Affiliation(s)
- Laura K Reynolds
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, United States of America.
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Ort BS, Cohen CS, Boyer KE, Wyllie-Echeverria S. Population structure and genetic diversity among eelgrass (Zostera marina) beds and depths in San Francisco Bay. J Hered 2012; 103:533-46. [PMID: 22577191 DOI: 10.1093/jhered/ess022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The seagrass Zostera marina is widely distributed in coastal regions throughout much of the northern hemisphere, forms the foundation of an important ecological habitat, and is suffering population declines. Studies in the Atlantic and Pacific oceans indicate that the degree of population genetic differentiation is location dependent. San Francisco Bay, California, USA, is a high-current, high-wind environment where rafting of seed-bearing shoots has the potential to enhance genetic connectivity among Z. marina populations. We tested Z. marina from six locations, including one annual population, within the bay to assess population differentiation and to compare levels of within-population genetic diversity. Using 7 microsatellite loci, we found significant differentiation among all populations. The annual population had significantly higher clonal diversity than the others but showed no detectible differences in heterozygosity or allelic richness. There appears to be sufficient input of genetic variation through sexual reproduction or immigration into the perennial populations to prevent significant declines in the number and frequency of alleles. In additional depth comparisons, we found differentiation among deep and shallow portions in 1 of 3 beds evaluated. Genetic drift, sweepstakes recruitment, dispersal limitation, and possibly natural selection may have combined to produce genetic differentiation over a spatial scale of 3-30 km in Z. marina. This implies that the scale of genetic differentiation may be smaller than expected for seagrasses in other locations too. We suggest that populations in close proximity may not be interchangeable for use as restoration material.
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Affiliation(s)
- Brian S Ort
- Romberg Tiburon Center for Environmental Studies, Department of Biology, San Francisco State University, Tiburon, CA 94920, USA.
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Kakinuma M, Inoue M, Morita T, Tominaga H, Maegawa M, Coury DA, Amano H. Isolation and characterization of a SEPALLATA-like gene, ZjMADS1, from marine angiosperm Zostera japonica. Mar Environ Res 2012; 76:128-137. [PMID: 22014762 DOI: 10.1016/j.marenvres.2011.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 08/31/2011] [Accepted: 09/27/2011] [Indexed: 05/31/2023]
Abstract
In flowering plants, floral homeotic MADS-box genes, which constitute a large multigene family, play important roles in the specification of floral organs as defined by the ABCDE model. In this study, a MADS-box gene, ZjMADS1, was isolated and characterized from the marine angiosperm Zostera japonica. The predicted length of the ZjMADS1 protein was 246 amino acids (AA), and the AA sequence was most similar to those of the SEPALLATA (SEP) subfamily, corresponding to E-function genes. Southern blot analysis suggested the presence of two SEP3-like genes in the Z. japonica genome. ZjMADS1 mRNA levels were extremely high in the spadices, regardless of the developmental stage, compared to other organs from the reproductive and vegetative shoots. These results suggest that the ZjMADS1 gene may be involved in spadix development in Z. japonica and act as an E-function gene in floral organ development in marine angiosperms.
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Affiliation(s)
- Makoto Kakinuma
- Laboratory of Marine Biochemistry, Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan.
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Abstract
PREMISE OF THE STUDY Polymorphic microsatellite primers were developed in the seagrass Zostera japonica to investigate genetic variation and to identify clonal structure. • METHODS AND RESULTS Thirteen polymorphic loci and 23 monomorphic loci were developed in Z. japonica. Two to 13 alleles per locus were observed at the polymorphic loci across 57 individuals of two Z. japonica populations. The observed and expected heterozygosities within populations ranged from 0.0000 to 1.0000 and from 0.0000 to 0.8542, respectively. • CONCLUSIONS Our study showed high-level polymorphism at the polymorphic loci in Z. japonica. These primers would be a powerful tool to study genetic variation, clonal structure, and mating systems.
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Affiliation(s)
- Kai Jiang
- Department of Environmental Sciences, East China Normal University, Shanghai 200062, China
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Chelsky Budarf A, Burfeind DD, Loh WKW, Tibbetts IR. Identification of seagrasses in the gut of a marine herbivorous fish using DNA barcoding and visual inspection techniques. J Fish Biol 2011; 79:112-121. [PMID: 21722114 DOI: 10.1111/j.1095-8649.2011.02999.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Traditional visual diet analysis techniques were compared with DNA barcoding in juvenile herbivorous rabbitfish Siganus fuscescens collected in Moreton Bay, Australia, where at least six species of seagrass occur. The intergenic spacer trnH-psbA, suggested as the optimal gene for barcoding angiosperms, was used for the first time to identify the seagrass in fish guts. Four seagrass species and one alga were identified visually from gut contents; however, there was considerable uncertainty in visual identification with 38 of 40 fish having unidentifiable plant fragments in their gut. PCR and single-strand conformational polymorphism (SSCP) were able to discriminate three seagrass families from visually cryptic gut contents. While effective in identifying cryptic gut content to family level, this novel method is likely to be most efficient when paired with visual identification techniques.
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Affiliation(s)
- A Chelsky Budarf
- School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, Qld 4072, Australia
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Zipperle AM, Coyer JA, Reise K, Stam WT, Olsen JL. An evaluation of small-scale genetic diversity and the mating system in Zostera noltii on an intertidal sandflat in the Wadden Sea. Ann Bot 2011; 107:127-34. [PMID: 21036695 PMCID: PMC3002472 DOI: 10.1093/aob/mcq214] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND AND AIMS The dwarf eelgrass, Zostera noltii, is a predominant inhabitant of soft-bottom intertidal regions along the coasts of northern Europe. It is a monoecious, protogynous angiosperm in which the potential for self-fertilization and inbreeding are high, especially if clone sizes exceed pollen dispersal distances. The aim of the present study was to determine the relationship between mating system and clonal structure, examine the relative roles of geitonogamous selfing and biparental inbreeding, measure pollen availability (multiple paternities) and estimate pollen dispersal. METHODS A 100-m(2) plot was established in a large, intertidal Z. noltii meadow on the island of Sylt in the German Wadden Sea. A total of 256 adult shoots was sampled: one from the centre of 100 fixed 1-m(2) quadrats (large scale resolution) and an additional 156 from within eight randomly selected 1-m(2) sub-quadrats (small-scale resolution). DNA was extracted from seeds and leaf tissue of all samples and genotyped with nine microsatellite loci. KEY RESULTS Mating system analysis revealed high multilocus and single locus outcrossing rates. Average pollen dispersal distance was nearly the same as the average genet (clone) size. Multiple paternity was common and 20-30 % of mature seeds originated from matings within the plot. Among inbred seeds, most resulted from geitonogamy rather than biparental inbreeding. CONCLUSIONS Moderate disturbances intrinsic to the intertidal habitat appear to facilitate seed recruitment by gap formation. Pollen dispersal distances are sufficient to maintain outcrossing and high clonal diversity.
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Affiliation(s)
- Andreas M. Zipperle
- Department of Marine Benthic Ecology & Evolution, Centre for Ecological and Evolutionary Studies, University of Groningen, Centre for Life Sciences, Nijenborgh 7, 9747 AG Groningen, The Netherlands
- For correspondence: E-mail
| | - James A. Coyer
- Department of Marine Benthic Ecology & Evolution, Centre for Ecological and Evolutionary Studies, University of Groningen, Centre for Life Sciences, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Karsten Reise
- Alfred Wegener Institute for Polar and Marine Research, Wadden Sea Station Sylt, 25992 List, Germany
| | - Wytze T. Stam
- Department of Marine Benthic Ecology & Evolution, Centre for Ecological and Evolutionary Studies, University of Groningen, Centre for Life Sciences, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jeanine L. Olsen
- Department of Marine Benthic Ecology & Evolution, Centre for Ecological and Evolutionary Studies, University of Groningen, Centre for Life Sciences, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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Affiliation(s)
- A Randall Hughes
- Bodega Marine Laboratory, University of California-Davis, P.O. Box 247, Bodega Bay, California 94923, USA.
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Reusch TBH, Veron AS, Preuss C, Weiner J, Wissler L, Beck A, Klages S, Kube M, Reinhardt R, Bornberg-Bauer E. Comparative analysis of expressed sequence tag (EST) libraries in the seagrass Zostera marina subjected to temperature stress. Mar Biotechnol (NY) 2008; 10:297-309. [PMID: 18239962 PMCID: PMC2757623 DOI: 10.1007/s10126-007-9065-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 10/27/2007] [Accepted: 11/01/2007] [Indexed: 05/20/2023]
Abstract
Global warming is associated with increasing stress and mortality on temperate seagrass beds, in particular during periods of high sea surface temperatures during summer months, adding to existing anthropogenic impacts, such as eutrophication and habitat destruction. We compare several expressed sequence tag (EST) in the ecologically important seagrass Zostera marina (eelgrass) to elucidate the molecular genetic basis of adaptation to environmental extremes. We compared the tentative unigene (TUG) frequencies of libraries derived from leaf and meristematic tissue from a control situation with two experimentally imposed temperature stress conditions and found that TUG composition is markedly different among these conditions (all P < 0.0001). Under heat stress, we find that 63 TUGs are differentially expressed (d.e.) at 25 degrees C compared with lower, no-stress condition temperatures (4 degrees C and 17 degrees C). Approximately one-third of d.e. eelgrass genes were characteristic for the stress response of the terrestrial plant model Arabidopsis thaliana. The changes in gene expression suggest complex photosynthetic adjustments among light-harvesting complexes, reaction center subunits of photosystem I and II, and components of the dark reaction. Heat shock encoding proteins and reactive oxygen scavengers also were identified, but their overall frequency was too low to perform statistical tests. In all conditions, the most abundant transcript (3-15%) was a putative metallothionein gene with unknown function. We also find evidence that heat stress may translate to enhanced infection by protists. A total of 210 TUGs contain one or more microsatellites as potential candidates for gene-linked genetic markers. Data are publicly available in a user-friendly database at http://www.uni-muenster.de/Evolution/ebb/Services/zostera .
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Affiliation(s)
- Thorsten B H Reusch
- Institute for Evolution & Biodiversity, Plant Evolutionary Ecology, University of Münster, Münster, Germany.
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Coyer JA, Miller KA, Engle JM, Veldsink J, Cabello-Pasini A, Stam WT, Olsen JL. Eelgrass meadows in the California Channel Islands and adjacent coast reveal a mosaic of two species, evidence for introgression and variable clonality. Ann Bot 2008; 101:73-87. [PMID: 18006507 PMCID: PMC2701847 DOI: 10.1093/aob/mcm288] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2007] [Revised: 08/30/2007] [Accepted: 10/01/2007] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Seagrasses are important facilitator species in shallow, soft-bottom marine environments worldwide and, in many places, are threatened by coastal development and eutrophication. One narrow-leaved species (Zostera marina) and one wide-leaved species, variously designated as Z. marina, Z. pacifica or Z. asiatica, are found off the California Channel Islands and adjacent California-Mexico coast. The aim of the present study was to confirm species identification genetically and to link patterns of genetic diversity, connectivity and hybridization among and within the populations with historical sea levels (Ice Age) or the contemporary environment. METHODS Samples (n = 11-100) were collected from 28 sites off five California Channel Islands and six sites off the adjacent coast of southern California and Baja California, Mexico. DNA polymorphisms of the rDNA-ITS (internal transcribed spacer) cistron (nuclear), the matK intron (chloroplast) and nine microsatellite loci (nuclear) were examined in a population genetic and phylogeographic context. KEY RESULTS All wide-leaved individuals were Z. pacifica, whereas narrow-leaved forms were Z. marina. Microsatellite genotypes were consistent with hybridization between the two species in three populations. The present distribution of Z. pacifica follows a glacial age land mass rather than present oceanographic regimes, but no link was observed between the present distribution of Z. marina and past or present environments. Island populations of Z. marina often were clonal and characterized by low genotypic diversity compared with populations along the Baja California coast. The high level of clonal connectivity around Santa Catalina Island indicated the importance of dispersal and subsequent re-establishment of vegetative fragments. CONCLUSIONS The pristine environmental conditions of offshore islands do not guarantee maximum genetic diversity. Future restoration and transplantation efforts of seagrasses must recognize cryptic species and consider the degree of both genetic and genotypic variation in candidate donor populations.
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Affiliation(s)
- J A Coyer
- Department of Marine Benthic Ecology and Evolution, Centre for Ecological and Evolutionary Studies, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands.
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Nielsen LW, Dahllöf I. Direct and indirect effects of the herbicides Glyphosate, Bentazone and MCPA on eelgrass (Zostera marina). Aquat Toxicol 2007; 82:47-54. [PMID: 17328972 DOI: 10.1016/j.aquatox.2007.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 01/20/2007] [Accepted: 01/21/2007] [Indexed: 05/14/2023]
Abstract
Eelgrass beds are important habitats for many organisms, but there has been a decline in the area covered by eelgrass during the last decades due to increased eutrophication resulting in increased shading from phytoplankton. The use of herbicides in terrestrial agriculture has also increased over the last century, and while the effects of herbicides on non-target organisms have been well studied in freshwater they are overlooked in coastal waters. It is not known if herbicides have any effect on the distribution of eelgrass (Zostera marina), or how natural phytoplankton communities respond to the same herbicides. Direct and indirect effects of the herbicides Glyphosate, Bentazone and MCPA both as single toxicants and as mixtures, on the eelgrass plants were investigated in this study. The direct effects on eelgrass were examined by measuring the four different endpoints; the relatively growth rate as length and weight, the chlorophyll a and b ratio, as well as the RNA-DNA ratio, at the end of a 3 days exposure period. The indirect effect was investigated by measuring the effect on a natural phytoplankton production from Roskilde Fjord six times during 1 year. The results showed that the chlorophyll a-b and RNA-DNA ratios were the most sensitive endpoints in single herbicide experiments. The effects of herbicide mixtures on eelgrass were much larger compared to the single substances. Nearly a halving was found for both the relatively growth rate in length and weight, and the RNA-DNA as well as the chlorophyll a-b ratios were also significant reduced. This indicates a possible synergistic effect, and calculations based on the concentration addition model indicate that the low concentrations mixture has a synergistic effect, whereas the high concentration mixture has an antagonistic effect on eelgrass (Z. marina). The low concentrations mixture is the one with the highest relevance for coastal areas. The effect on phytoplankton showed some variation over the year but mainly in a stimulation in primary production. This means that herbicides affect eelgrass both directly and indirectly.
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Affiliation(s)
- Line Winkel Nielsen
- Department of Marine Ecology, National Environmental Research Institute, 4000 Roskilde, Denmark
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Abstract
Physical disturbance has often been invoked to control genotypic diversity in sessile clonal organisms, yet experimental evidence is lacking. I studied the effects of physical disturbance on genet dynamics and genotypic diversity in a clonal marine angiosperm, Zostera marina (eelgrass). In replicated plots of 1 m2, the vegetation canopy was removed in gaps of zero (control), 25%, 50% and 75% of the area (n = 6 replicates). Before removal and during two consecutive years, the genotypic composition was determined using genetic markers (DNA microsatellites) in a 5 x 5 pixel grid per plot. An aggregate index of genet dynamics summarizing recruitment, increase, loss and decrease of clones was maximal at intermediate disturbance levels (quadratic polynomial P = 0.02). Physical disturbance also increased the occurrence of new genotypes, possibly reflecting recruitment (linear model, P < 0.05). Contrary to expectations, there was no competitive advantage of more heterozygous genotypes over less heterozygous ones. In the absence of disturbance, in particular, clones with lower individual heterozygosity were more likely to increase in area over a 1-year time period than more heterozygous ones, while there was no such correlation in plots with disturbance (logistic model, P(disturbance x heterozygosity) = 0.036). Undisturbed plots revealed background recruitment independent of canopy gaps, suggesting that Z. marina exhibits a strategy of continual recruitment. Effects of experimental disturbance (linear or quadratic) on clonal diversity were not detectable. Instead, initial (pretreatment) clonal diversity accounted for between 68% and 91% of the variance in diversity, indicating remarkable resilience of genotypic diversity in the face of physical disturbance.
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Affiliation(s)
- Thorsten B H Reusch
- Max-Planck-Institut für Limnologie, August-Thienemann-Str. 2, 24306 Plön, Germany.
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Muñiz-Salazar R, Talbot SL, Sage GK, Ward DH, Cabello-Pasini A. Population genetic structure of annual and perennial populations of Zostera marina L. along the Pacific coast of Baja California and the Gulf of California. Mol Ecol 2005; 14:711-22. [PMID: 15723663 DOI: 10.1111/j.1365-294x.2005.02454.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Baja California peninsula represents a biogeographical boundary contributing to regional differentiation among populations of marine animals. We investigated the genetic characteristics of perennial and annual populations of the marine angiosperm, Zostera marina, along the Pacific coast of Baja California and in the Gulf of California, respectively. Populations of Z. marina from five coastal lagoons along the Pacific coast and four sites in the Gulf of California were studied using nine microsatellite loci. Analyses of variance revealed significant interregional differentiation, but no subregional differentiation. Significant spatial differentiation, assessed using theta(ST) values, was observed among all populations within the two regions. Z. marina populations along the Pacific coast are separated by more than 220 km and had the greatest theta(ST) (0.13-0.28) values, suggesting restricted gene flow. In contrast, lower but still significant genetic differentiation was observed among populations within the Gulf of California (theta(ST) = 0.04-0.18), even though populations are separated by more than 250 km. This suggests higher levels of gene flow among Gulf of California populations relative to Pacific coast populations. Direction of gene flow was predominantly southward among Pacific coast populations, whereas no dominant polarity in the Gulf of California populations was observed. The test for isolation by distance (IBD) showed a significant correlation between genetic and geographical distances in Gulf of California populations, but not in Pacific coast populations, perhaps because of shifts in currents during El Niño Southern Oscillation (ENSO) events along the Pacific coast.
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Affiliation(s)
- Raquel Muñiz-Salazar
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California A.P. 453, Ensenada, Baja California 22800, México.
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Hämmerli A, Reusch TBH. Genetic neighbourhood of clone structures in eelgrass meadows quantified by spatial autocorrelation of microsatellite markers. Heredity (Edinb) 2004; 91:448-55. [PMID: 14576737 DOI: 10.1038/sj.hdy.6800310] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Limited dispersal distances in plant populations frequently cause local genetic structure, which can be quantified by spatial autocorrelation. In clonal plants, three levels of spatial organization can contribute to positive autocorrelation; namely, the neighbourhood of (a) ramets, (b) clone fragments and (c) entire clones. Here we use data from an exhaustive sampling scheme on a clonal plant to measure the contribution of the neighbourhoods of each distinct clonal structure to total spatial autocorrelation. Four plots (256 grid points each) within dense meadows of the marine clonal plant Zostera marina (eelgrass) were sampled for clone structure with nine microsatellite markers ( approximately 80 alleles). We found significant coancestry (f(ij)), at all three levels of spatial organization, even when not allowing for joins between samples of identical genets. In addition, absolute values of f(ij) and the maximum distance with significant positive f(ij) decreased with the progressive exclusion of joins between alike genotypes. The neighbourhood of this clonal plant thus consists of three levels of organization, which are reflected in different kinship structures. Each of these kinship structures may affect the level of biparental inbreeding and the physical distance between flowering shoots and their outcrossing neighbourhood. These results also emphasize the notion that spatial autocorrelation crucially depends on the scale and intensity of sampling.
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Affiliation(s)
- A Hämmerli
- 1Max Planck Institute for Limnology, August-Thienemann-Str. 2, D-24306 Plön, Germany.
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Abstract
Motivated by recent global reductions in biodiversity, empirical and theoretical research suggests that more species-rich systems exhibit enhanced productivity, nutrient cycling, or resistance to disturbance or invasion relative to systems with fewer species. In contrast, few data are available to assess the potential ecosystem-level importance of genetic diversity within species known to play a major functional role. Using a manipulative field experiment, we show that increasing genotypic diversity in a habitat-forming species (the seagrass Zostera marina) enhances community resistance to disturbance by grazing geese. The time required for recovery to near predisturbance densities also decreases with increasing eelgrass genotypic diversity. However, there is no effect of diversity on resilience, measured as the rate of shoot recovery after the disturbance, suggesting that more rapid recovery in diverse plots is due solely to differences in disturbance resistance. Genotypic diversity did not affect ecosystem processes in the absence of disturbance. Thus, our results suggest that genetic diversity, like species diversity, may be most important for enhancing the consistency and reliability of ecosystems by providing biological insurance against environmental change.
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Affiliation(s)
- A Randall Hughes
- Section of Evolution and Ecology, One Shields Avenue, University of California, Davis, CA 95616, USA.
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Abstract
Many functionally hermaphroditic plants have evolved mechanisms to reduce interference between the sex functions and to optimize reproductive output. In addition to physical mechanisms such as the spatial (herkogamy) and temporal (dichogamy) separation of male and female functions, plasticity in sex expression by means of mate-recognition (flexible mating) could be important in plants with variable access to cross-pollen. This applies particularly to clonal plants because of their modular growth form. We experimentally tested for the effects of pollen source and vegetative neighbourhood on instantaneous sex ratio and seed production in the self-compatible clonal marine angiosperm Zostera marina L. To this end, we exposed the (monoecious) flowering shoots to self and cross-pollen and to neighbourhoods of their own and a mix of foreign vegetative shoots. Flowering shoots that had been exposed to cross-pollen showed (1) a significantly lower female/male ratio at peak flowering, evidence for mate-recognition, and (2) a significantly higher seed set by the end of the season. Both effects were independent of the genetic composition of their vegetative neighbourhood. The results suggest that Z. marina maintains a cryptic self-incompatibility system not previously described for angiosperms with sub-aqueous pollination. In Z. marina, and possibly other self-compatible clonal plant species, mate-recognition could be a means of increasing the out-crossing probability for flowering shoots with central positions within their clone.
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Affiliation(s)
- A Hämmerli
- Max Planck Institute for Limnology, Plön, Germany.
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Tanaka N, Kuo J, Omori Y, Nakaoka M, Aioi K. Phylogenetic relationships in the genera Zostera and Heterozostera (Zosteraceae) based on matK sequence data. J Plant Res 2003; 116:273-279. [PMID: 12942336 DOI: 10.1007/s10265-003-0090-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2002] [Accepted: 02/24/2003] [Indexed: 05/24/2023]
Abstract
Phylogenetic analysis of the plastid (chloroplast) DNA matK gene of Zosteraceae species was undertaken. A molecular phylogenetic tree based on matK sequence data showed the monophyly of Heterozostera tasmanica and subgenus Zosterella and did not support the separation of Heterozostera from the genus Zostera. The tree based on matK supported the monophyly of the subgenus Zostera, and showed that Zosteraceae consist of three main groups: Phyllospadix, which is clearly defined by being dioecious; the subgenus Zosterella and Heterozostera; and the subgenus Zostera. Character-state reconstruction of chromosome number and geographic distribution for our molecular phylogenetic tree showed that 2 n=12 is a plesiomorphic character for Zostera and Heterozostera, that the chromosome number was doubled or tripled in two lineages, and that the initial speciation of Zostera and Heterozostera occurred in the Northern Hemisphere. The matK tree showed the close affinity of Z. noltii and Z. japonica, which have disjunct distributions. Zostera marina, which is the only widely distributed species in the subgenus Zostera, also occurring in the northern Atlantic, was shown to be embedded within other subgenus Zostera species.
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Affiliation(s)
- Norio Tanaka
- Tsukuba Botanical Garden, National Science Museum, 4-1-1 Amakubo, Tsukuba 305-0005 Japan.
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Abstract
Although inbreeding depression is a major genetic phenomena influencing individual fitness, it is difficult to measure in wild populations. An alternative approach is to correlate heterozygosity, measured using highly polymorphic markers, with a fitness-correlated trait. In clonal plants, genet size is predicted to be fitness correlated. Here we test the prediction that the genet size distribution of the marine clonal plant Zostera marina (eelgrass) is influenced by inbreeding depression. We used nine polymorphic microsatellite markers to access the fine scale clonal structure and to measure individual heterozygosity within 4 plots (each corresponds to 256 m2, sampled at 1-m intervals) in two populations along the German Baltic Coast. The same plots were also sampled for flowering and vegetative shoots to obtain estimates for sexual reproductive output at the level of the genetic individual. We found substantial differences in the genet size distribution between the two populations that may be explained by different disturbance frequency. In both populations, clone size was significantly positively correlated with the total number of flowering shoots, indicating that larger clones have a higher reproductive output. Individual heterozygosity was significantly positively associated with clone size. The effect was much stronger in Falkenstein (low disturbance) than in Maasholm (high disturbance). The results indicate that in a low disturbance population the relatively outbred clones occupy a higher proportion of the available space, possibly because they outcompete relatively inbred neighbours.
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Affiliation(s)
- A Hämmerli
- Max Planck Institute for Limnology, August-Thienemann-Str. 2, D-24306 Plön, Germany.
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Kato Y, Aioi K, Omori Y, Takahata N, Satta Y. Phylogenetic analyses of Zostera species based on rbcL and matK nucleotide sequences: Implications for the origin and diversification of seagrasses in Japanese waters. Genes Genet Syst 2003; 78:329-42. [PMID: 14676424 DOI: 10.1266/ggs.78.329] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Seagrasses are composed of four families belonging to angiosperms and they are thought to become adaptive to aquatic life independently. Zosteraceae is one such family and because of the relatively high species diversity around Japan and Korea coast areas, the family might have arisen therefrom. To elucidate the origin and evolution of Zosteraceae which consists of three genera, Phyllospadix, Zostera, and Heterozostera, 2.8 kb nucleotide sequences of rbcL and matK genes in the chloroplast genome were examined for various species, including cosmopolitan Z. marina and endemic Z. caulescens. The phylogenetic analysis reveals the following three features. First, based on the synonymous nucleotide substitution rate of the rice chloroplast genome, we estimated the divergence times between Zosteraceae and its closest relative, Potamogetonaceae, and between different genera, Zostera and Phyllospadix, as approximately 100 million years (myr) and 36 myr, respectively, suggesting that Zosteraceae emerged somewhere in the period from 36 myr ago to 100 myr ago. Second, two subgenera of Zostera, Zostera and Zosterella, exhibit their reciprocal monophyly and appear to have differentiated from each other approximately 33 myr ago. However, the third genus Heterozostera branched off only 5 myr ago from the stem lineage leading to Zosterella and this seems too recent in comparison with the ancient divergence of the two subgenera. Third, we estimated the most recent common ancestor of subgenus Zostera as 6 myr. In Z. marina four haplotypes were found in the sample and have diversified in the past 1.5 myr. One haplotype is shared by both sides of the Japan Archipelago and its closely related haplotypes occur also in eastern Pacific Ocean. Based on these phylogeographic analyses, we propose a provisional age related classification of Zosteraceae to argue the origin and evolution.
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Affiliation(s)
- Yumiko Kato
- Department of Biosystems Science, The Graduate University for Advanced Studies (Sokendai), Hayama, Kanagawa, Japan
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