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Caisová L. Draparnaldia: a chlorophyte model for comparative analyses of plant terrestrialization. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3305-3313. [PMID: 32100007 DOI: 10.1093/jxb/eraa102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 02/25/2020] [Indexed: 05/22/2023]
Abstract
It is generally accepted that land plants evolved from streptophyte algae. However, there are also many chlorophytes (a sister group of streptophyte algae and land plants) that moved to terrestrial habitats and even resemble mosses. This raises the question of why no land plants evolved from chlorophytes. In order to better understand what enabled streptophyte algae to conquer the land, it is necessary to study the chlorophytes as well. This review will introduce the freshwater filamentous chlorophyte alga Draparnaldia sp. (Chaetophorales, Chlorophyceae) as a model for comparative analyses between these two lineages. It will also focus on current knowledge about the evolution of morphological complexity in chlorophytes versus streptophytes and their respective morphological/behavioural adaptations to semi-terrestrial habitats, and will show why Draparnaldia is needed as a new model system.
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Affiliation(s)
- Lenka Caisová
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Woodhouse Lane, Leeds, UK
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Fürst-Jansen JMR, de Vries S, de Vries J. Evo-physio: on stress responses and the earliest land plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3254-3269. [PMID: 31922568 PMCID: PMC7289718 DOI: 10.1093/jxb/eraa007] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/07/2020] [Indexed: 05/19/2023]
Abstract
Embryophytes (land plants) can be found in almost any habitat on the Earth's surface. All of this ecologically diverse embryophytic flora arose from algae through a singular evolutionary event. Traits that were, by their nature, indispensable for the singular conquest of land by plants were those that are key for overcoming terrestrial stressors. Not surprisingly, the biology of land plant cells is shaped by a core signaling network that connects environmental cues, such as stressors, to the appropriate responses-which, thus, modulate growth and physiology. When did this network emerge? Was it already present when plant terrestrialization was in its infancy? A comparative approach between land plants and their algal relatives, the streptophyte algae, allows us to tackle such questions and resolve parts of the biology of the earliest land plants. Exploring the biology of the earliest land plants might shed light on exactly how they overcame the challenges of terrestrialization. Here, we outline the approaches and rationale underlying comparative analyses towards inferring the genetic toolkit for the stress response that aided the earliest land plants in their conquest of land.
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Affiliation(s)
- Janine M R Fürst-Jansen
- University of Göttingen, Institute for Microbiology and Genetics, Department of Applied Bioinformatics, Göttingen, Germany
| | - Sophie de Vries
- Population Genetics, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Jan de Vries
- University of Göttingen, Institute for Microbiology and Genetics, Department of Applied Bioinformatics, Göttingen, Germany
- University of Göttingen, Göttingen Center for Molecular Biosciences (GZMB), Göttingen, Germany
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Konrad W, Katul G, Roth-Nebelsick A, Jensen KH. Xylem functioning, dysfunction and repair: a physical perspective and implications for phloem transport. TREE PHYSIOLOGY 2019; 39:243-261. [PMID: 30299503 DOI: 10.1093/treephys/tpy097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/31/2018] [Accepted: 08/08/2018] [Indexed: 05/02/2023]
Abstract
Xylem and phloem are the two main conveyance systems in plants allowing exchanges of water and carbohydrates between roots and leaves. While each system has been studied in isolation for well over a century, the coupling and coordination between them remains the subject of inquiry and active research and frames the scope of the review here. Using a set of balance equations, hazards of bubble formation and their role in shaping xylem pressure and its corollary impact on phloem pressure and sugar transport are featured. The behavior of an isolated and freely floating air bubble within the xylem is first analyzed so as to introduce key principles such as the Helmholtz free energy and its links to embryonic bubble sizes. These principles are extended by considering bubbles filled with water vapor and air arising from air seeding. Using this framework, key results about stability and hazards of bubbles in contact with xylem walls are discussed. A chemical equilibrium between phloem and xylem systems is then introduced to link xylem and osmotic pressures. The consequences of such a link for sugar concentration needed to sustain efficient phloem transport by osmosis in the loading zone is presented. Catastrophic cases where phloem dysfunction occurs are analyzed in terms of xylem function and its vulnerability to cavitation. A link between operating pressures in the soil system bounded by field capacity and wilting points and maintenance of phloem functioning are discussed as conjectures to be tested in the future.
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Affiliation(s)
- Wilfried Konrad
- Department of Geosciences, University of Tübingen, Hoelderlinstrasse 12, Tübingen, Germany
- Institute of Botany, Technische Universität Dresden, Zellescher Weg 20b, Dresden, Germany
| | - Gabriel Katul
- Nicholas School of the Environment and Earth Sciences, Levine Science Research Center, Duke University, Durham, NC, USA
| | - Anita Roth-Nebelsick
- Deptartment of Palaeontology, State Museum of Natural History Stuttgart, Rosenstein 1, Stuttgart, Germany
| | - Kaare H Jensen
- Department of Physics, Technical University of Denmark, Fysikvej Building 309, Kgs. Lyngby, Denmark
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Voss LJ, McAdam SAM, Knoblauch M, Rathje JM, Brodribb T, Hedrich R, Roelfsema MRG. Guard cells in fern stomata are connected by plasmodesmata, but control cytosolic Ca 2+ levels autonomously. THE NEW PHYTOLOGIST 2018; 219:206-215. [PMID: 29655174 DOI: 10.1111/nph.15153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 03/06/2018] [Indexed: 05/10/2023]
Abstract
Recent studies have revealed that some responses of fern stomata to environmental signals differ from those of their relatives in seed plants. However, it is unknown whether the biophysical properties of guard cells differ fundamentally between species of both clades. Intracellular micro-electrodes and the fluorescent Ca2+ reporter FURA2 were used to study voltage-dependent cation channels and Ca2+ signals in guard cells of the ferns Polypodium vulgare and Asplenium scolopendrium. Voltage clamp experiments with fern guard cells revealed similar properties of voltage-dependent K+ channels as found in seed plants. However, fluorescent dyes moved within the fern stomata, from one guard cell to the other, which does not occur in most seed plants. Despite the presence of plasmodesmata, which interconnect fern guard cells, Ca2+ signals could be elicited in each of the cells individually. Based on the common properties of voltage-dependent channels in ferns and seed plants, it is likely that these key transport proteins are conserved in vascular plants. However, the symplastic connections between fern guard cells in mature stomata indicate that the biophysical mechanisms that control stomatal movements differ between ferns and seed plants.
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Affiliation(s)
- Lena J Voss
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Würzburg University, Julius-von-Sachs-Platz 2, D-97082, Würzburg, Germany
| | - Scott A M McAdam
- School of Biological Science, University of Tasmania, Hobart, TAS, 7001, Australia
- Botany and Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN, 47907, USA
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA, 99164-4236, USA
| | - Jan M Rathje
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Würzburg University, Julius-von-Sachs-Platz 2, D-97082, Würzburg, Germany
| | - Tim Brodribb
- School of Biological Science, University of Tasmania, Hobart, TAS, 7001, Australia
| | - Rainer Hedrich
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Würzburg University, Julius-von-Sachs-Platz 2, D-97082, Würzburg, Germany
| | - M Rob G Roelfsema
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Würzburg University, Julius-von-Sachs-Platz 2, D-97082, Würzburg, Germany
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de Vries J, Archibald JM. Plant evolution: landmarks on the path to terrestrial life. THE NEW PHYTOLOGIST 2018; 217:1428-1434. [PMID: 29318635 DOI: 10.1111/nph.14975] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 11/28/2017] [Indexed: 05/20/2023]
Abstract
UNLABELLED Contents Summary 1428 I. The singularity of plant terrestrialization 1428 II. Adaptation vs exaptation - what shaped the land plant toolkit? 1430 III. Trait mosaicism in (higher-branching) streptophyte algae 1431 IV. CONCLUSIONS a streptophyte algal perspective on land plant trait evolution 1432 Acknowledgements 1432 ORCID 1433 References 1433 SUMMARY: Photosynthetic eukaryotes thrive anywhere there is sunlight and water. But while such organisms are exceptionally diverse in form and function, only one phototrophic lineage succeeded in rising above its substrate: the land plants (embryophytes). Molecular phylogenetic data show that land plants evolved from streptophyte algae most closely related to extant Zygnematophyceae, and one of the principal aims of plant evolutionary biology is to uncover the key features of such algae that enabled this important transition. At the present time, however, mosaic and reductive evolution blur our picture of the closest algal ancestors of plants. Here we discuss recent progress and problems in inferring the biology of the algal progenitor of the terrestrial photosynthetic macrobiome.
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Affiliation(s)
- Jan de Vries
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
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Raven JA, Colmer TD. Life at the boundary: photosynthesis at the soil-fluid interface. A synthesis focusing on mosses. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:1613-23. [PMID: 26842980 DOI: 10.1093/jxb/erw012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Mosses are among the earliest branching embryophytes and probably originated not later than the early Ordovician when atmospheric CO2 was higher and O2 was lower than today. The C3 biochemistry and physiology of their photosynthesis suggests, by analogy with tracheophytes, that growth of extant bryophytes in high CO2 approximating Ordovician values would increase the growth rate. This occurs for many mosses, including Physcomitrella patens in suspension culture, although recently published transcriptomic data on this species at high CO2 and present-day CO2 show down-regulation of the transcription of several genes related to photosynthesis. It would be useful if transcriptomic (and proteomic) data comparing growth conditions are linked to measurements of growth and physiology on the same, or parallel, cultures. Mosses (like later-originating embryophytes) have been subject to changes in bulk atmospheric CO2 and O2 throughout their existence, with evidence, albeit limited, for positive selection of moss Rubisco. Extant mosses are subject to a large range of CO2 and O2 concentrations in their immediate environments, especially aquatic mosses, and mosses are particularly influenced by CO2 generated by, and O2 consumed by, soil chemoorganotrophy from organic C produced by tracheophytes (if present) and bryophytes.
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Affiliation(s)
- John A Raven
- Permanent address: Division of Plant Sciences, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK School of Plant Biology, The University of Western Australia, M084, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Timothy D Colmer
- School of Plant Biology, The University of Western Australia, M084, 35 Stirling Highway, Crawley, WA 6009, Australia
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Raven JA. Polar auxin transport in relation to long-distance transport of nutrients in the Charales. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:1-9. [PMID: 23264638 DOI: 10.1093/jxb/ers358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
This paper examines the significance of the recent demonstration of polar auxin transport (PAT) in the green macroalga Chara (Charophyceae: Charales) and, especially, options for explaining some features of PAT in the Charales. The occurrence of PAT in the Charales shows that PAT originated in the algal ancestors of the embryophytes (liverworts, mosses, hornworts, and vascular plants), although it is not yet known if PAT occurs elsewhere in the Charophyceae or in other algae. While in the embryophytes PAT occurs in parenchymatously constructed structures which commonly also have xylem and phloem (or their bryophyte analogues) as long-distance transport processes in parallel to PAT, in Chara corallina PAT shares the pathway for long-distance transport of nutrients though the parenchymatously constructed nodal complexes and the single giant cells of the internode. The speed of auxin movement of PAT is much more rapid than that attributable to diffusion and of the same order as the rate of cytoplasmic streaming in the giant internodal cells, yet complete inhibition of streaming by the inhibitor cytochalasin H does not slow down auxin transport. Explanations for this phenomenon are sought in the operation of other mechanochemical motors, dynein-tubulin and kinesin-tubulin, as alternatives to the myosin-actin system which powers cytoplasmic streaming. Experiments in which microtubules are disrupted, for example by colchicine, could show if one of the tubulin-based motors is involved. If these motors are involved, some mechanism is needed to amplify the speeds known for the motors to explain the order of magnitude higher speeds seen for auxin transport.
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Affiliation(s)
- John A Raven
- Division of Plant Sciences, University of Dundee at James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK.
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