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Zhang L, Ambrose C. Beauty is more than epidermis deep: How cell division and expansion sculpt the leaf spongy mesophyll. CURRENT OPINION IN PLANT BIOLOGY 2024; 79:102542. [PMID: 38688201 DOI: 10.1016/j.pbi.2024.102542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/16/2024] [Accepted: 04/02/2024] [Indexed: 05/02/2024]
Abstract
As the main location of photosynthesis, leaf mesophyll cells are one of the most abundant and essential cell types on earth. Forming the bulk of the internal tissues of the leaf, their size, shape, and patterns of interconnectivity define the internal structure and surface area of the leaf, which in turn determines the efficiency of light capture and carbon fixation. Understanding how these cellular traits are controlled and translated into tissue- and organ-scale traits, and how they influence photosynthetic performance will be key to our ability to improve crop plants in the face of a changing climate. In contrast to the extensive literature on the anatomical and physiological aspects of mesophyll function, our understanding of the cell-level morphogenetic processes underpinning mesophyll cell growth and differentiation is scant. In this review, we focus on how cell division, expansion, and separation are coordinated to create the intricate architecture of the spongy mesophyll.
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Affiliation(s)
- Liyong Zhang
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N0X2, Canada
| | - Chris Ambrose
- Department of Biology, College of Arts and Science, University of Saskatchewan, Saskatoon, S7N 5E2, Saskatchewan, Canada.
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2
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Jobert F, Yadav S, Robert S. Auxin as an architect of the pectin matrix. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6933-6949. [PMID: 37166384 PMCID: PMC10690733 DOI: 10.1093/jxb/erad174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/10/2023] [Indexed: 05/12/2023]
Abstract
Auxin is a versatile plant growth regulator that triggers multiple signalling pathways at different spatial and temporal resolutions. A plant cell is surrounded by the cell wall, a complex and dynamic network of polysaccharides. The cell wall needs to be rigid to provide mechanical support and protection and highly flexible to allow cell growth and shape acquisition. The modification of the pectin components, among other processes, is a mechanism by which auxin activity alters the mechanical properties of the cell wall. Auxin signalling precisely controls the transcriptional output of several genes encoding pectin remodelling enzymes, their local activity, pectin deposition, and modulation in different developmental contexts. This review examines the mechanism of auxin activity in regulating pectin chemistry at organ, cellular, and subcellular levels across diverse plant species. Moreover, we ask questions that remain to be addressed to fully understand the interplay between auxin and pectin in plant growth and development.
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Affiliation(s)
- François Jobert
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umeå, Sweden
- CRRBM, Université de Picardie Jules Verne, 80000, Amiens, France
| | - Sandeep Yadav
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umeå, Sweden
| | - Stéphanie Robert
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umeå, Sweden
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3
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Paterlini A, Sechet J, Immel F, Grison MS, Pilard S, Pelloux J, Mouille G, Bayer EM, Voxeur A. Enzymatic fingerprinting reveals specific xyloglucan and pectin signatures in the cell wall purified with primary plasmodesmata. FRONTIERS IN PLANT SCIENCE 2022; 13:1020506. [PMID: 36388604 PMCID: PMC9640925 DOI: 10.3389/fpls.2022.1020506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Plasmodesmata (PD) pores connect neighbouring plant cells and enable direct transport across the cell wall. Understanding the molecular composition of these structures is essential to address their formation and later dynamic regulation. Here we provide a biochemical characterisation of the cell wall co-purified with primary PD of Arabidopsis thaliana cell cultures. To achieve this result we combined subcellular fractionation, polysaccharide analyses and enzymatic fingerprinting approaches. Relative to the rest of the cell wall, specific patterns were observed in the PD fraction. Most xyloglucans, although possibly not abundant as a group, were fucosylated. Homogalacturonans displayed short methylated stretches while rhamnogalacturonan I species were remarkably abundant. Full rhamnogalacturonan II forms, highly methyl-acetylated, were also present. We additionally showed that these domains, compared to the broad wall, are less affected by wall modifying activities during a time interval of days. Overall, the protocol and the data presented here open new opportunities for the study of wall polysaccharides associated with PD.
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Affiliation(s)
- A. Paterlini
- Laboratoire de Biogenèse Membranaire, Unité mixte de recherche (UMR5200), Université Bordeaux, Centre national de la recherche scientifique (CNRS), Villenave d’Ornon, France
| | - J. Sechet
- Institut Jean-Pierre Bourgin (IJPB), Université Paris-Saclay, Institut National de Recherche pour l'Agriculture, l'alimentation et l'Environnement (INRAE), AgroParisTech, Versailles, France
| | - F. Immel
- Laboratoire de Biogenèse Membranaire, Unité mixte de recherche (UMR5200), Université Bordeaux, Centre national de la recherche scientifique (CNRS), Villenave d’Ornon, France
| | - M. S. Grison
- Laboratoire de Biogenèse Membranaire, Unité mixte de recherche (UMR5200), Université Bordeaux, Centre national de la recherche scientifique (CNRS), Villenave d’Ornon, France
| | - S. Pilard
- Plateforme Analytique, Université de Picardie, Amiens, France
| | - J. Pelloux
- UMRT (Unité Mixte de Recherche Transfrontaliére) INRAE (Institut National de recherche pour l'Agriculture, l'alimentation et l'Environnement) 1158 BioEcoAgro – BIOPI Biologie des Plantes et Innovation, Université de Picardie, Amiens, France
| | - G. Mouille
- Institut Jean-Pierre Bourgin (IJPB), Université Paris-Saclay, Institut National de Recherche pour l'Agriculture, l'alimentation et l'Environnement (INRAE), AgroParisTech, Versailles, France
| | - E. M. Bayer
- Laboratoire de Biogenèse Membranaire, Unité mixte de recherche (UMR5200), Université Bordeaux, Centre national de la recherche scientifique (CNRS), Villenave d’Ornon, France
| | - A. Voxeur
- Institut Jean-Pierre Bourgin (IJPB), Université Paris-Saclay, Institut National de Recherche pour l'Agriculture, l'alimentation et l'Environnement (INRAE), AgroParisTech, Versailles, France
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4
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Khoshravesh R, Hoffmann N, Hanson DT. Leaf microscopy applications in photosynthesis research: identifying the gaps. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:1868-1893. [PMID: 34986250 DOI: 10.1093/jxb/erab548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
Leaf imaging via microscopy has provided critical insights into research on photosynthesis at multiple junctures, from the early understanding of the role of stomata, through elucidating C4 photosynthesis via Kranz anatomy and chloroplast arrangement in single cells, to detailed explorations of diffusion pathways and light utilization gradients within leaves. In recent decades, the original two-dimensional (2D) explorations have begun to be visualized in three-dimensional (3D) space, revising our understanding of structure-function relationships between internal leaf anatomy and photosynthesis. In particular, advancing new technologies and analyses are providing fresh insight into the relationship between leaf cellular components and improving the ability to model net carbon fixation, water use efficiency, and metabolite turnover rate in leaves. While ground-breaking developments in imaging tools and techniques have expanded our knowledge of leaf 3D structure via high-resolution 3D and time-series images, there is a growing need for more in vivo imaging as well as metabolite imaging. However, these advances necessitate further improvement in microscopy sciences to overcome the unique challenges a green leaf poses. In this review, we discuss the available tools, techniques, challenges, and gaps for efficient in vivo leaf 3D imaging, as well as innovations to overcome these difficulties.
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Affiliation(s)
| | - Natalie Hoffmann
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - David T Hanson
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
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5
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Riddled with holes: Understanding air space formation in plant leaves. PLoS Biol 2021; 19:e3001475. [PMID: 34871299 PMCID: PMC8675916 DOI: 10.1371/journal.pbio.3001475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/16/2021] [Indexed: 11/19/2022] Open
Abstract
Plants use energy from sunlight to transform carbon dioxide from the air into complex organic molecules, ultimately producing much of the food we eat. To make this complex chemistry more efficient, plant leaves are intricately constructed in 3 dimensions: They are flat to maximise light capture and contain extensive internal air spaces to increase gas exchange for photosynthesis. Many years of work has built up an understanding of how leaves form flat blades, but the molecular mechanisms that control air space formation are poorly understood. Here, I review our current understanding of air space formation and outline how recent advances can be harnessed to answer key questions and take the field forward. Increasing our understanding of plant air spaces will not only allow us to understand a fundamental aspect of plant development, but also unlock the potential to engineer the internal structure of crops to make them more efficient at photosynthesis with lower water requirements and more resilient in the face of a changing environment. Leaves are interwoven with large air spaces to increase the efficiency of photosynthesis; however, how these air spaces form and how different patterns have evolved is almost unknown. This Unsolved Mystery article discusses the existing evidence and poses new avenues of research to answer this question.
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Apostolakos P, Giannoutsou E, Galatis B. Callose: a multifunctional (1, 3)-β-D-glucan involved in morphogenesis and function of angiosperm stomata. ACTA ACUST UNITED AC 2021; 28:17. [PMID: 34344461 PMCID: PMC8330052 DOI: 10.1186/s40709-021-00150-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/20/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND Although the cellulose microfibril organization in guard cell (GC) walls play a crucial role in the mechanism of the stomatal function, recent work showed that matrix cell wall materials are also involved. Especially in the kidney-shaped stomata of the fern Asplenium nidus, callose actively participates in the mechanism of opening and closure of the stomatal pore. SCOPE The present review briefly presents and discusses recent findings concerning the distribution and role of callose in the kidney-shaped stomata of the dicotyledon Vigna sinensis as well as in the dumbbell-shaped stomata of the monocotyledon Zea mays. CONCLUSION The discussed data support that, in both categories of angiosperm stomata, callose is implicated in the mechanism of stomatal pore formation and stomata function by locally affecting the mechanical properties of the GC cell walls.
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Affiliation(s)
- Panagiotis Apostolakos
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, Athens, Greece.
| | - Eleni Giannoutsou
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Basil Galatis
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
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7
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Antreich SJ, Xiao N, Huss JC, Gierlinger N. A belt for the cell: cellulosic wall thickenings and their role in morphogenesis of the 3D puzzle cells in walnut shells. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4744-4756. [PMID: 33963747 PMCID: PMC8219037 DOI: 10.1093/jxb/erab197] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/03/2021] [Indexed: 05/25/2023]
Abstract
Walnut (Juglans regia) kernels are protected by a tough shell consisting of polylobate sclereids that interlock into a 3D puzzle. The shape transformations from isodiametric to lobed cells is well documented for 2D pavement cells, but not for 3D puzzle sclereids. Here, we study the morphogenesis of these cells by using a combination of different imaging techniques. Serial face-microtomy enabled us to reconstruct tissue growth of whole walnut fruits in 3D, and serial block face-scanning electron microscopy exposed cell shapes and their transformation in 3D during shell tissue development. In combination with Raman and fluorescence microscopy, we revealed multiple loops of cellulosic thickenings in cell walls, acting as stiff restrictions during cell growth and leading to the lobed cell shape. Our findings contribute to a better understanding of the 3D shape transformation of polylobate sclereids and the role of pectin and cellulose within this process.
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Affiliation(s)
- Sebastian J Antreich
- Department of Nanobiotechnology, Institute of Biophysics, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Nannan Xiao
- Department of Nanobiotechnology, Institute of Biophysics, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Jessica C Huss
- Department of Nanobiotechnology, Institute of Biophysics, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Notburga Gierlinger
- Department of Nanobiotechnology, Institute of Biophysics, University of Natural Resources and Life Sciences, Vienna, Austria
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8
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Zhang L, McEvoy D, Le Y, Ambrose C. Live imaging of microtubule organization, cell expansion, and intercellular space formation in Arabidopsis leaf spongy mesophyll cells. THE PLANT CELL 2021; 33:623-641. [PMID: 33955495 PMCID: PMC8136880 DOI: 10.1093/plcell/koaa036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/24/2020] [Indexed: 05/30/2023]
Abstract
Leaf spongy mesophyll cells form an interconnected network of branched cells and intercellular spaces to maximize the surface area available for light capture and photosynthetic gas exchange. To investigate the morphogenetic events leading to cell separation and branching in Arabidopsis thaliana, we used mesophyll-specific promoters to facilitate imaging of mesophyll cell shape and microtubule (MT) organization over multiple spatiotemporal scales without interference from the overlying epidermal cells. We show that cells enlarge by selective expansion of cell wall regions in contact with intercellular spaces. Cell-cell contacts remain relatively fixed in size, forming the termini of interconnecting branches. Surprisingly, classic schizogeny (de-adhesion of neighboring cells) is relatively infrequent, being related to the local topology of cell junctions during early expansion. Intercellular spaces cue the position of stable MT bundles, which in turn promote efficient dilation of intercellular spaces and cell branching. Our data provide insights into mesophyll morphogenesis and MT organization and lay the groundwork for future investigations.
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Affiliation(s)
- Liyong Zhang
- Department of Biology, College of Arts and Science, University of Saskatchewan, Saskatoon, S7N 5E2, Saskatchewan, Canada
| | - Delanie McEvoy
- Department of Biology, College of Arts and Science, University of Saskatchewan, Saskatoon, S7N 5E2, Saskatchewan, Canada
| | - Yen Le
- Department of Biology, College of Arts and Science, University of Saskatchewan, Saskatoon, S7N 5E2, Saskatchewan, Canada
| | - Chris Ambrose
- Department of Biology, College of Arts and Science, University of Saskatchewan, Saskatoon, S7N 5E2, Saskatchewan, Canada
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9
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Chemical composition of cell wall changes during developmental stages of galls on Matayba guianensis (Sapindaceae): perspectives obtained by immunocytochemistry analysis. Naturwissenschaften 2021; 108:16. [PMID: 33871712 DOI: 10.1007/s00114-021-01732-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 03/16/2021] [Accepted: 04/12/2021] [Indexed: 10/21/2022]
Abstract
The development of plant organs depends on cell division, elongation, structural and chemical changes, and reorganization of cell wall components. As phenotype manipulators, galling insects can manipulate the structure and metabolism of host tissues to build the gall. The gall formation depends on the rearrangement of cell wall components to allow cell growth and elongation, key step for the knowledge regarding gall development, and shape acquisition. Herein, we used an immunocytochemical approach to investigate the chemical composition of the cell wall during the development of galls induced by Bystracoccus mataybae (Eriococcidae) on leaflets of Matayba guianensis (Sapindaceae). Different developmental stages of non-galled leaflets (n = 10) and of leaflet galls (n = 10) were collected from the Cerrado (Brazilian savanna) for anatomical and immunocytochemical analysis. We found that the epitopes of (1 → 4) β-D-galactans and (1 → 5) α-L-arabinans were evident in the tissues of the young and senescent galls. These epitopes seem to be associated with the mechanical stability maintenance and increased gall porosity. As well, the degree of methyl-esterification of pectins changed from the young to the senescent galls and revealed the conservation of juvenile cell and tissue features even in the senescent galls. The extensins detected in senescent galls seem to support their rigidity and structural reinforcement of these bodies. Our results showed a disruption in the pattern of deposition of leaflet cell wall for the construction of M. guianensis galls, with pectin and protein modulation associated with the change of the developmental gall stages.
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10
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Wilson MJ, Fradera‐Soler M, Summers R, Sturrock CJ, Fleming AJ. Ploidy influences wheat mesophyll cell geometry, packing and leaf function. PLANT DIRECT 2021; 5:e00314. [PMID: 33855257 PMCID: PMC8026107 DOI: 10.1002/pld3.314] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/08/2020] [Accepted: 02/21/2021] [Indexed: 05/06/2023]
Abstract
Leaf function is influenced by leaf structure, which is itself related not only to the spatial arrangement of constituent mesophyll cells, but also their size and shape. In this study, we used confocal microscopy to image leaves of Triticum genotypes varying in ploidy level to extract 3D information on individual mesophyll cell size and geometry. Combined with X-ray Computed Tomography and gas exchange analysis, the effect of changes in wheat mesophyll cell geometry upon leaf structure and function were investigated. Mesophyll cell size and shape were found to have changed during the course of wheat evolution. An unexpected linear relationship between mesophyll cell surface area and volume was discovered, suggesting anisotropic scaling of mesophyll cell geometry with increasing ploidy. Altered mesophyll cell size and shape were demonstrated to be associated with changes in mesophyll tissue architecture. Under experimental growth conditions, CO2 assimilation did not vary with ploidy, but stomatal conductance was lower in hexaploid plants, conferring a greater instantaneous water-use efficiency. We propose that as wheat mesophyll cells have become larger with increased ploidy, this has been accompanied by changes in cell geometry and packing which limit water loss while maintaining carbon assimilation.
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Affiliation(s)
- Matthew J. Wilson
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | - Marc Fradera‐Soler
- Department of Plant and Environmental SciencesUniversity of CopenhagenCopenhagenDenmark
- Hounsfield FacilityDivision of Agriculture and Environmental SciencesSchool of BiosciencesUniversity of NottinghamSutton BoningtonUK
| | | | - Craig J. Sturrock
- Hounsfield FacilityDivision of Agriculture and Environmental SciencesSchool of BiosciencesUniversity of NottinghamSutton BoningtonUK
| | - Andrew J. Fleming
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
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11
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Meidani C, Ntalli NG, Giannoutsou E, Adamakis IDS. Cell Wall Modifications in Giant Cells Induced by the Plant Parasitic Nematode Meloidogyne incognita in Wild-Type (Col-0) and the fra2 Arabidopsis thaliana Katanin Mutant. Int J Mol Sci 2019; 20:E5465. [PMID: 31684028 PMCID: PMC6862268 DOI: 10.3390/ijms20215465] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 12/21/2022] Open
Abstract
Meloidogyne incognita is a root knot nematode (RKN) species which is among the most notoriously unmanageable crop pests with a wide host range. It inhabits plants and induces unique feeding site structures within host roots, known as giant cells (GCs). The cell walls of the GCs undergo the process of both thickening and loosening to allow expansion and finally support nutrient uptake by the nematode. In this study, a comparative in situ analysis of cell wall polysaccharides in the GCs of wild-type Col-0 and the microtubule-defective fra2 katanin mutant, both infected with M. incognita has been carried out. The fra2 mutant had an increased infection rate. Moreover, fra2 roots exhibited a differential pectin and hemicellulose distribution when compared to Col-0 probably mirroring the fra2 root developmental defects. Features of fra2 GC walls include the presence of high-esterified pectic homogalacturonan and pectic arabinan, possibly to compensate for the reduced levels of callose, which was omnipresent in GCs of Col-0. Katanin severing of microtubules seems important in plant defense against M. incognita, with the nematode, however, to be nonchalant about this "katanin deficiency" and eventually induce the necessary GC cell wall modifications to establish a feeding site.
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Affiliation(s)
- Christianna Meidani
- Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens, 157 84 Athens, Greece.
| | - Nikoletta G Ntalli
- Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 14561 Athens, Greece.
| | - Eleni Giannoutsou
- Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens, 157 84 Athens, Greece.
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12
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Danila FR, Quick WP, White RG, von Caemmerer S, Furbank RT. Response of plasmodesmata formation in leaves of C 4 grasses to growth irradiance. PLANT, CELL & ENVIRONMENT 2019; 42:2482-2494. [PMID: 30965390 DOI: 10.1111/pce.13558] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/27/2019] [Indexed: 06/09/2023]
Abstract
Rapid metabolite diffusion across the mesophyll (M) and bundle sheath (BS) cell interface in C4 leaves is a key requirement for C4 photosynthesis and occurs via plasmodesmata (PD). Here, we investigated how growth irradiance affects PD density between M and BS cells and between M cells in two C4 species using our PD quantification method, which combines three-dimensional laser confocal fluorescence microscopy and scanning electron microscopy. The response of leaf anatomy and physiology of NADP-ME species, Setaria viridis and Zea mays to growth under different irradiances, low light (100 μmol m-2 s-1 ), and high light (1,000 μmol m-2 s-1 ), was observed both at seedling and established growth stages. We found that the effect of growth irradiance on C4 leaf PD density depended on plant age and species. The high light treatment resulted in two to four-fold greater PD density per unit leaf area than at low light, due to greater area of PD clusters and greater PD size in high light plants. These results along with our finding that the effect of light on M-BS PD density was not tightly linked to photosynthetic capacity suggest a complex mechanism underlying the dynamic response of C4 leaf PD formation to growth irradiance.
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Affiliation(s)
- Florence R Danila
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - William Paul Quick
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- International Rice Research Institute, Los Baños, Laguna, 4030, Philippines
- University of Sheffield, Sheffield, UK
| | - Rosemary G White
- CSIRO Agriculture and Food, Canberra, Australian Capital Territory, 2601, Australia
| | - Susanne von Caemmerer
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Robert T Furbank
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- CSIRO Agriculture and Food, Canberra, Australian Capital Territory, 2601, Australia
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13
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Guerriero G, Stokes I, Exley C. Is callose required for silicification in plants? Biol Lett 2018; 14:rsbl.2018.0338. [PMID: 30282746 PMCID: PMC6227863 DOI: 10.1098/rsbl.2018.0338] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 09/07/2018] [Indexed: 12/15/2022] Open
Abstract
The cell wall polymer callose catalyses the formation of silica in vitro and is heavily implicated in biological silicification in Equisetum (horsetail) and Arabidopsis (thale cress) in vivo. Callose, a β-1,3-glucan, is an ideal partner for silicification, because its amorphous structure and ephemeral nature provide suitable microenvironments to support the condensation of silicic acid into silica. Herein, using scanning electron microscopy, immunohistochemistry and fluorescence, we provide further evidence of the cooperative nature of callose and silica in biological silicification in rice, an important crop plant and known silica accumulator. These new data along with recently published research enable us to propose a model to describe the intracellular events that together determine callose-driven biological silicification.
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Affiliation(s)
- Gea Guerriero
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Esche/Alzette, Luxembourg
| | - Ian Stokes
- The Birchall Centre, Lennard-Jones Laboratories, Keele University, Staffordshire, UK
| | - Christopher Exley
- The Birchall Centre, Lennard-Jones Laboratories, Keele University, Staffordshire, UK
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14
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Sotiriou P, Giannoutsou E, Panteris E, Galatis B, Apostolakos P. Local differentiation of cell wall matrix polysaccharides in sinuous pavement cells: its possible involvement in the flexibility of cell shape. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:223-237. [PMID: 29247575 DOI: 10.1111/plb.12681] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 12/08/2017] [Indexed: 06/07/2023]
Abstract
The distribution of homogalacturonans (HGAs) displaying different degrees of esterification as well as of callose was examined in cell walls of mature pavement cells in two angiosperm and two fern species. We investigated whether local cell wall matrix differentiation may enable pavement cells to respond to mechanical tension forces by transiently altering their shape. HGA epitopes, identified with 2F4, JIM5 and JIM7 antibodies, and callose were immunolocalised in hand-made or semithin leaf sections. Callose was also stained with aniline blue. The structure of pavement cells was studied with light and transmission electron microscopy (TEM). In all species examined, pavement cells displayed wavy anticlinal cell walls, but the waviness pattern differed between angiosperms and ferns. The angiosperm pavement cells were tightly interconnected throughout their whole depth, while in ferns they were interconnected only close to the external periclinal cell wall and intercellular spaces were developed between them close to the mesophyll. Although the HGA epitopes examined were located along the whole cell wall surface, the 2F4- and JIM5- epitopes were especially localised at cell lobe tips. In fern pavement cells, the contact sites were impregnated with callose and JIM5-HGA epitopes. When tension forces were applied on leaf regions, the pavement cells elongated along the stretching axis, due to a decrease in waviness of anticlinal cell walls. After removal of tension forces, the original cell shape was resumed. The presented data support that HGA epitopes make the anticlinal pavement cell walls flexible, in order to reversibly alter their shape. Furthermore, callose seems to offer stability to cell contacts between pavement cells, as already suggested in photosynthetic mesophyll cells.
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Affiliation(s)
- P Sotiriou
- Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - E Giannoutsou
- Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - E Panteris
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - B Galatis
- Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - P Apostolakos
- Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
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15
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Wang S, Tholen D, Zhu X. C 4 photosynthesis in C 3 rice: a theoretical analysis of biochemical and anatomical factors. PLANT, CELL & ENVIRONMENT 2017; 40:80-94. [PMID: 27628301 PMCID: PMC6139432 DOI: 10.1111/pce.12834] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/08/2016] [Accepted: 09/10/2016] [Indexed: 05/05/2023]
Abstract
Engineering C4 photosynthesis into rice has been considered a promising strategy to increase photosynthesis and yield. A question that remains to be answered is whether expressing a C4 metabolic cycle into a C3 leaf structure and without removing the C3 background metabolism improves photosynthetic efficiency. To explore this question, we developed a 3D reaction diffusion model of bundle-sheath and connected mesophyll cells in a C3 rice leaf. Our results show that integrating a C4 metabolic pathway into rice leaves with a C3 metabolism and mesophyll structure may lead to an improved photosynthesis under current ambient CO2 concentration. We analysed a number of physiological factors that influence the CO2 uptake rate, which include the chloroplast surface area exposed to intercellular air space, bundle-sheath cell wall thickness, bundle-sheath chloroplast envelope permeability, Rubisco concentration and the energy partitioning between C3 and C4 cycles. Among these, partitioning of energy between C3 and C4 photosynthesis and the partitioning of Rubisco between mesophyll and bundle-sheath cells are decisive factors controlling photosynthetic efficiency in an engineered C3 -C4 leaf. The implications of the results for the sequence of C4 evolution are also discussed.
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Affiliation(s)
- Shuyue Wang
- Key Laboratory of Computational Biology, CAS‐MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghai200031China
- University of Chinese Academy of SciencesBeijing100049China
| | - Danny Tholen
- Institute of Botany, Department of Integrative BiologyUniversity of Natural Resources and Applied Life Sciences, BOKU ViennaGregor‐Mendel‐Str. 33A‐1180ViennaAustria
| | - Xin‐Guang Zhu
- Key Laboratory of Computational Biology, CAS‐MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghai200031China
- University of Chinese Academy of SciencesBeijing100049China
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16
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Giannoutsou E, Apostolakos P, Galatis B. Spatio-temporal diversification of the cell wall matrix materials in the developing stomatal complexes of Zea mays. PLANTA 2016; 244:1125-1143. [PMID: 27460945 DOI: 10.1007/s00425-016-2574-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/20/2016] [Indexed: 05/02/2023]
Abstract
The matrix cell wall materials, in developing Zea mays stomatal complexes are asymmetrically distributed, a phenomenon appearing related to the local cell wall expansion and deformation, the establishment of cell polarity, and determination of the cell division plane. In cells of developing Zea mays stomatal complexes, definite cell wall regions expand determinately and become locally deformed. This differential cell wall behavior is obvious in the guard cell mother cells (GMCs) and the subsidiary cell mother cells (SMCs) that locally protrude towards the adjacent GMCs. The latter, emitting a morphogenetic stimulus, induce polarization/asymmetrical division in SMCs. Examination of immunolabeled specimens revealed that homogalacturonans (HGAs) with a high degree of de-esterification (2F4- and JIM5-HGA epitopes) and arabinogalactan proteins are selectively distributed in the extending and deformed cell wall regions, while their margins are enriched with rhamnogalacturonans (RGAs) containing highly branched arabinans (LM6-RGA epitope). In SMCs, the local cell wall matrix differentiation constitutes the first structural event, indicating the establishment of cell polarity. Moreover, in the premitotic GMCs and SMCs, non-esterified HGAs (2F4-HGA epitope) are preferentially localized in the cell wall areas outlining the cytoplasm where the preprophase band is formed. In these areas, the forthcoming cell plate fuses with the parent cell walls. These data suggest that the described heterogeneity in matrix cell wall materials is probably involved in: (a) local cell wall expansion and deformation, (b) the transduction of the inductive GMC stimulus, and
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Affiliation(s)
- E Giannoutsou
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, 15784, Athens, Greece
| | - P Apostolakos
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, 15784, Athens, Greece
| | - B Galatis
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, 15784, Athens, Greece.
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17
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Becker M, Becker Y, Green K, Scott B. The endophytic symbiont Epichloë festucae establishes an epiphyllous net on the surface of Lolium perenne leaves by development of an expressorium, an appressorium-like leaf exit structure. THE NEW PHYTOLOGIST 2016; 211:240-54. [PMID: 26991322 PMCID: PMC5069595 DOI: 10.1111/nph.13931] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 02/07/2016] [Indexed: 05/16/2023]
Abstract
Epichloë festucae forms a mutualistic symbiotic association with Lolium perenne. This biotrophic fungus systemically colonizes the intercellular spaces of aerial tissues to form an endophytic hyphal network. E. festucae also grows as an epiphyte, but the mechanism for leaf surface colonization is not known. Here we identify an appressorium-like structure, which we call an expressorium that allows endophytic hyphae to penetrate the cuticle from the inside of the leaf to establish an epiphytic hyphal net on the surface of the leaf. We used a combination of scanning electron, transmission electron and confocal laser scanning microscopy to characterize this novel fungal structure and determine the composition of the hyphal cell wall using aniline blue and wheat germ agglutinin labelled with Alexafluor-488. Expressoria differentiate immediately below the cuticle in the leaf blade and leaf sheath intercalary cell division zones where the hyphae grow by tip growth. Differentiation of this structure requires components of both the NoxA and NoxB NADPH oxidase complexes. Major remodelling of the hyphal cell wall occurs following exit from the leaf. These results establish that the symbiotic association of E. festucae with L. perenne involves an interconnected hyphal network of both endophytic and epiphytic hyphae.
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Affiliation(s)
- Matthias Becker
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- IGZ – Leibniz Institute of Vegetable and Ornamental Crops14979GroßbeerenGermany
| | - Yvonne Becker
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- IGZ – Leibniz Institute of Vegetable and Ornamental Crops14979GroßbeerenGermany
| | - Kimberly Green
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
| | - Barry Scott
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
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18
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Sotiriou P, Giannoutsou E, Panteris E, Apostolakos P, Galatis B. Cell wall matrix polysaccharide distribution and cortical microtubule organization: two factors controlling mesophyll cell morphogenesis in land plants. ANNALS OF BOTANY 2016; 117:401-19. [PMID: 26802013 PMCID: PMC4765543 DOI: 10.1093/aob/mcv187] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/27/2015] [Accepted: 11/05/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS This work investigates the involvement of local differentiation of cell wall matrix polysaccharides and the role of microtubules in the morphogenesis of mesophyll cells (MCs) of three types (lobed, branched and palisade) in the dicotyledon Vigna sinensis and the fern Asplenium nidus. METHODS Homogalacturonan (HGA) epitopes recognized by the 2F4, JIM5 and JIM7 antibodies and callose were immunolocalized in hand-made leaf sections. Callose was also stained with aniline blue. We studied microtubule organization by tubulin immunofluorescence and transmission electron microscopy. RESULTS In both plants, the matrix cell wall polysaccharide distribution underwent definite changes during MC differentiation. Callose constantly defined the sites of MC contacts. The 2F4 HGA epitope in V. sinensis first appeared in MC contacts but gradually moved towards the cell wall regions facing the intercellular spaces, while in A. nidus it was initially localized at the cell walls delimiting the intercellular spaces, but finally shifted to MC contacts. In V. sinensis, the JIM5 and JIM7 HGA epitopes initially marked the cell walls delimiting the intercellular spaces and gradually shifted in MC contacts, while in A. nidus they constantly enriched MC contacts. In all MC types examined, the cortical microtubules played a crucial role in their morphogenesis. In particular, in palisade MCs, cortical microtubule helices, by controlling cellulose microfibril orientation, forced these MCs to acquire a truncated cone-like shape. Unexpectedly in V. sinensis, the differentiation of colchicine-affected MCs deviated completely, since they developed a cell wall ingrowth labyrinth, becoming transfer-like cells. CONCLUSIONS The results of this work and previous studies on Zea mays (Giannoutsou et al., Annals of Botany 2013; 112: : 1067-1081) revealed highly controlled local cell wall matrix differentiation in MCs of species belonging to different plant groups. This, in coordination with microtubule-dependent cellulose microfibril alignment, spatially controlled cell wall expansion, allowing MCs to acquire their particular shape.
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Affiliation(s)
- P Sotiriou
- Department of Botany, Faculty of Biology, University of Athens, Athens 15784, Greece and
| | - E Giannoutsou
- Department of Botany, Faculty of Biology, University of Athens, Athens 15784, Greece and
| | - E Panteris
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - P Apostolakos
- Department of Botany, Faculty of Biology, University of Athens, Athens 15784, Greece and
| | - B Galatis
- Department of Botany, Faculty of Biology, University of Athens, Athens 15784, Greece and
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19
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Knox JP, Benitez-Alfonso Y. Roles and regulation of plant cell walls surrounding plasmodesmata. CURRENT OPINION IN PLANT BIOLOGY 2014; 22:93-100. [PMID: 25286000 DOI: 10.1016/j.pbi.2014.09.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/16/2014] [Accepted: 09/20/2014] [Indexed: 05/28/2023]
Abstract
In plants, the intercellular transport of simple and complex molecules can occur symplastically through plasmodesmata. These are membranous channels embedded in cell walls that connect neighbouring cells. The properties of the cell walls surrounding plasmodesmata determine their transport capacity and permeability. These cell wall micro-domains are enriched in callose and have a characteristic pectin distribution. Cell wall modifications, leading to changes in plasmodesmata structure, have been reported to occur during development and in response to environmental signals. Cell wall remodelling enzymes target plasmodesmata to rapidly control intercellular communication in situ. Here we describe current knowledge on the composition of cell walls at plasmodesmata sites and on the proteins and signals that modify cell walls to regulate plasmodesmata aperture.
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Affiliation(s)
- J Paul Knox
- Centre for Plant Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Yoselin Benitez-Alfonso
- Centre for Plant Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
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