51
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Moreno S, Canales J, Hong L, Robinson D, Roeder AH, Gutiérrez RA. Nitrate Defines Shoot Size through Compensatory Roles for Endoreplication and Cell Division in Arabidopsis thaliana. Curr Biol 2020; 30:1988-2000.e3. [DOI: 10.1016/j.cub.2020.03.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/29/2020] [Accepted: 03/13/2020] [Indexed: 12/15/2022]
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52
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Zhu M, Chen W, Mirabet V, Hong L, Bovio S, Strauss S, Schwarz EM, Tsugawa S, Wang Z, Smith RS, Li CB, Hamant O, Boudaoud A, Roeder AHK. Robust organ size requires robust timing of initiation orchestrated by focused auxin and cytokinin signalling. NATURE PLANTS 2020; 6:686-698. [PMID: 32451448 PMCID: PMC7299778 DOI: 10.1038/s41477-020-0666-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 04/15/2020] [Indexed: 05/02/2023]
Abstract
Organ size and shape are precisely regulated to ensure proper function. The four sepals in each Arabidopsis thaliana flower must maintain the same size throughout their growth to continuously enclose and protect the developing bud. Here we show that DEVELOPMENT RELATED MYB-LIKE 1 (DRMY1) is required for both timing of organ initiation and proper growth, leading to robust sepal size in Arabidopsis. Within each drmy1 flower, the initiation of some sepals is variably delayed. Late-initiating sepals in drmy1 mutants remain smaller throughout development, resulting in variability in sepal size. DRMY1 focuses the spatiotemporal signalling patterns of the plant hormones auxin and cytokinin, which jointly control the timing of sepal initiation. Our findings demonstrate that timing of organ initiation, together with growth and maturation, contribute to robust organ size.
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Affiliation(s)
- Mingyuan Zhu
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY, USA
| | - Weiwei Chen
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY, USA
- Key Laboratory of Horticulture Science for Southern Mountains Regions of Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, Beibei, China
- Academy of Agricultural Sciences of Southwest University, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Beibei, China
| | - Vincent Mirabet
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon, France
- Lycée Auguste et Louis Lumière, Lyon, France
| | - Lilan Hong
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY, USA
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Simone Bovio
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon, France
| | - Soeren Strauss
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Erich M Schwarz
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Satoru Tsugawa
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Zhou Wang
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY, USA
| | - Richard S Smith
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- John Innes Centre, Norwich, UK
| | - Chun-Biu Li
- Department of Mathematics, Stockholm University, Stockholm, Sweden
| | - Olivier Hamant
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon, France
| | - Arezki Boudaoud
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon, France.
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY, USA.
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53
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Vadde BVL, Roeder AHK. Can the French flag and reaction-diffusion models explain flower patterning? Celebrating the 50th anniversary of the French flag model. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2886-2897. [PMID: 32016398 DOI: 10.1093/jxb/eraa065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/01/2020] [Indexed: 05/25/2023]
Abstract
It has been 50 years since Lewis Wolpert introduced the French flag model proposing the patterning of different cell types based on threshold concentrations of a morphogen diffusing in the tissue. Sixty-seven years ago, Alan Turing introduced the idea of patterns initiating de novo from a reaction-diffusion network. Together these models have been used to explain many patterning events in animal development, so here we take a look at their applicability to flower development. First, although many plant transcription factors move through plasmodesmata from cell to cell, in the flower there is little evidence that they specify fate in a concentration-dependent manner, so they cannot yet be described as morphogens. Secondly, the reaction-diffusion model appears to be a reasonably good description of the formation of spots of pigment on petals, although additional nuances are present. Thirdly, aspects of both of these combine in a new fluctuation-based patterning system creating the scattered pattern of giant cells in Arabidopsis sepals. In the future, more precise imaging and manipulations of the dynamics of patterning networks combined with mathematical modeling will allow us to better understand how the multilayered complex and beautiful patterns of flowers emerge de novo.
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Affiliation(s)
- Batthula Vijaya Lakshmi Vadde
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY, USA
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY, USA
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Rambaud-Lavigne L, Hay A. Floral organ development goes live. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2472-2478. [PMID: 31970400 PMCID: PMC7210761 DOI: 10.1093/jxb/eraa038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/20/2020] [Indexed: 05/19/2023]
Abstract
The chance to watch floral organs develop live is not to be missed! Here, we outline reasons why quantitative, live-cell imaging is an important approach to study floral morphogenesis, and provide a basic workflow of how to get started. We highlight key advances in morphodynamics of lateral organ development, and discuss recent work that uses live confocal imaging to address the regulation of floral organ number, its robustness, and patterning mechanisms that exploit stochasticity.
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Affiliation(s)
- Léa Rambaud-Lavigne
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg, Köln, Germany
| | - Angela Hay
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg, Köln, Germany
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55
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3D morphological analysis of Arabidopsis sepals. Methods Cell Biol 2020. [PMID: 32896325 DOI: 10.1016/bs.mcb.2020.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
How complicated cell activities produce characteristic tissue and organ morphologies is an important question in plant morphogenesis. To address this question, 3D morphometry of plant organs on multiscales is indispensable. In recent years, advances in confocal microscopy with fluorescent probes that mark the cell wall or plasma membrane enable the visualization of organ morphology with submicron precision. In parallel, new quantitative and correlative imaging pipelines realize 3D image processing on 2D curved surface, facilitating the study of cell and tissue behaviors in plant organogenesis. Here, we describe methods for 3D morphometry of Arabidopsis sepals, focusing on live imaging coupled with MorphoGraphX-based 3D image processing for cellular growth analysis.
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MpFEW RHIZOIDS1 miRNA-Mediated Lateral Inhibition Controls Rhizoid Cell Patterning in Marchantia polymorpha. Curr Biol 2020; 30:1905-1915.e4. [PMID: 32243863 DOI: 10.1016/j.cub.2020.03.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/18/2020] [Accepted: 03/12/2020] [Indexed: 01/27/2023]
Abstract
Lateral inhibition patterns differentiated cell types among equivalent cells during development in bacteria, metazoans, and plants. Tip-growing rhizoid cells develop among flat epidermal cells in the epidermis of the early-diverging land plant Marchantia polymorpha. We show that the majority of rhizoid cells develop individually, but some develop in linear, one-dimensional groups (chains) of between 2 and 7 rhizoid cells in wild-type plants. The distribution of rhizoid cells can be accounted for within a simple cellular automata model of lateral inhibition. The model predicted that in the absence of lateral inhibition, two-dimensional rhizoid cell groups (clusters) form. These can be larger than those formed with lateral inhibition. M. polymorpha rhizoid differentiation is positively regulated by the ROOT HAIR DEFECTIVE SIX-LIKE1 (MpRSL1) basic-helix-loop-helix (bHLH) transcription factor, which is directly repressed by the FEW RHIZOIDS1 (MpFRH1) microRNA (miRNA). To test if MpFRH1 miRNA acts during lateral inhibition, we generated loss-of-function (lof) mutants without the MpFRH1 miRNA. Two-dimensional clusters of rhizoids develop in Mpfrh1lof mutants as predicted by the model for plants that lack lateral inhibition. Furthermore, two-dimensional clusters of up to 9 rhizoid cells developed in the Mpfrh1lof mutants compared to a maximum number of 7 observed in wild-type groups. The higher steady-state levels of MpRSL1 mRNA in Mpfrh1lof mutants indicate that MpFRH1-mediated lateral inhibition involves the repression of MpRSL1 activity. Together, the modeling and genetic data indicate that MpFRH1 miRNA mediates lateral inhibition by repressing MpRSL1 during pattern formation in the M. polymorpha epidermis.
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57
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A signal cascade originated from epidermis defines apical-basal patterning of Arabidopsis shoot apical meristems. Nat Commun 2020; 11:1214. [PMID: 32139673 PMCID: PMC7058014 DOI: 10.1038/s41467-020-14989-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 02/11/2020] [Indexed: 11/22/2022] Open
Abstract
In multicellular organisms, a long-standing question is how spatial patterns of distinct cell types are initiated and maintained during continuous cell division and proliferation. Along the vertical axis of plant shoot apical meristems (SAMs), stem cells are located at the top while cells specifying the stem cells are located more basally, forming a robust apical-basal pattern. We previously found that in Arabidopsis SAMs, the HAIRY MERISTEM (HAM) family transcription factors form a concentration gradient from the epidermis to the interior cell layers, and this gradient is essential for the stem cell specification and the apical-basal patterning of the SAMs. Here, we uncover that epidermis specific transcription factors, ARABIDOPSIS THALIANA MERISTEM LAYER 1 (ATML1) and its close homolog, define the concentration gradient of HAM in the SAM through activating a group of microRNAs. This study provides a molecular framework linking the epidermis-derived signal to the stem cell homeostasis in plants. A concentration gradient of HAM transcription factors specifies apical-basal patterning in the Arabidopsis shoot apical meristem. Here, the authors show that epidermal expression of the ATML1 transcription factor defines this concentration gradient via activation of mobile micro RNA.
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58
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Beentjes CHL, Perez-Carrasco R, Grima R. Exact solution of stochastic gene expression models with bursting, cell cycle and replication dynamics. Phys Rev E 2020; 101:032403. [PMID: 32290003 DOI: 10.1103/physreve.101.032403] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/10/2020] [Indexed: 06/11/2023]
Abstract
The bulk of stochastic gene expression models in the literature do not have an explicit description of the age of a cell within a generation and hence they cannot capture events such as cell division and DNA replication. Instead, many models incorporate the cell cycle implicitly by assuming that dilution due to cell division can be described by an effective decay reaction with first-order kinetics. If it is further assumed that protein production occurs in bursts, then the stationary protein distribution is a negative binomial. Here we seek to understand how accurate these implicit models are when compared with more detailed models of stochastic gene expression. We derive the exact stationary solution of the chemical master equation describing bursty protein dynamics, binomial partitioning at mitosis, age-dependent transcription dynamics including replication, and random interdivision times sampled from Erlang or more general distributions; the solution is different for single lineage and population snapshot settings. We show that protein distributions are well approximated by the solution of implicit models (a negative binomial) when the mean number of mRNAs produced per cycle is low and the cell cycle length variability is large. When these conditions are not met, the distributions are either almost bimodal or else display very flat regions near the mode and cannot be described by implicit models. We also show that for genes with low transcription rates, the size of protein noise has a strong dependence on the replication time, it is almost independent of cell cycle variability for lineage measurements, and increases with cell cycle variability for population snapshot measurements. In contrast for large transcription rates, the size of protein noise is independent of replication time and increases with cell cycle variability for both lineage and population measurements.
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Affiliation(s)
- Casper H L Beentjes
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Ruben Perez-Carrasco
- Department of Mathematics, University College London, London WC1H 0AY, United Kingdom
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
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59
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Slovak R, Setzer C, Roiuk M, Bertels J, Göschl C, Jandrasits K, Beemster GTS, Busch W. Ribosome assembly factor Adenylate Kinase 6 maintains cell proliferation and cell size homeostasis during root growth. THE NEW PHYTOLOGIST 2020; 225:2064-2076. [PMID: 31665812 PMCID: PMC7028144 DOI: 10.1111/nph.16291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/19/2019] [Indexed: 05/06/2023]
Abstract
From the cellular perspective, organ growth is determined by production and growth of cells. Uncovering how these two processes are coordinated is essential for understanding organogenesis and regulation of organ growth. We utilized phenotypic and genetic variation of 252 natural accessions of Arabidopsis thaliana to conduct genome-wide association studies (GWAS) for identifying genes underlying root growth variation; using a T-DNA line candidate approach, we identified one gene involved in root growth control and characterized its function using microscopy, root growth kinematics, G2/M phase cell count, ploidy levels and ribosome polysome profiles. We identified a factor contributing to root growth control: Arabidopsis Adenylate Kinase 6 (AAK6). AAK6 is required for normal cell production and normal cell elongation, and its natural genetic variation is involved in determining root growth differences between Arabidopsis accessions. A lack of AAK6 reduces cell production in the aak6 root apex, but this is partially compensated for by longer mature root cells. Thereby, aak6 mutants exhibit compensatory cell enlargement, a phenomenon unexpected in roots. Moreover, aak6 plants accumulate 80S ribosomes while the polysome profile remains unchanged, consistent with a phenotype of perturbed ribosome biogenesis. In conclusion, AAK6 impacts ribosome abundance, cell production and thereby root growth.
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Affiliation(s)
- Radka Slovak
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Claudia Setzer
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
| | - Mykola Roiuk
- Max F. Perutz Laboratories (MFPL)Vienna Biocenter (VBC)Dr Bohr‐Gasse 91030ViennaAustria
| | - Jonas Bertels
- Laboratory for Integrated Molecular Plant Physiology Research (IMPRES)Department of BiologyUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Christian Göschl
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
| | - Katharina Jandrasits
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
| | - Gerrit T. S. Beemster
- Laboratory for Integrated Molecular Plant Physiology Research (IMPRES)Department of BiologyUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Wolfgang Busch
- Gregor Mendel Institute (GMI)Austrian Academy of SciencesVienna Biocenter (VBC)Dr Bohr‐Gasse 31030ViennaAustria
- Plant Molecular and Cellular Biology LaboratorySalk Institute For Biological Studies10010 N Torrey Pines RdLa JollaCA92037USA
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60
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Abstract
A new way to culture and image flowers is uncovering the processes that take place in reproductive cells buried deep in plants.
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Affiliation(s)
- Rui Wang
- Department of Molecular Genetics, Ohio State UniversityColumbusUnited States
| | - Anna A Dobritsa
- Department of Molecular Genetics, Ohio State UniversityColumbusUnited States
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61
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Tsugawa S. Suppression of soft spots and excited modes in the shape deformation model with spatio-temporal growth noise. J Theor Biol 2020; 486:110092. [DOI: 10.1016/j.jtbi.2019.110092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 10/20/2019] [Accepted: 11/22/2019] [Indexed: 10/25/2022]
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62
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Ripoll JJ, Zhu M, Brocke S, Hon CT, Yanofsky MF, Boudaoud A, Roeder AHK. Growth dynamics of the Arabidopsis fruit is mediated by cell expansion. Proc Natl Acad Sci U S A 2019; 116:25333-25342. [PMID: 31757847 PMCID: PMC6911193 DOI: 10.1073/pnas.1914096116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fruit have evolved a sophisticated tissue and cellular architecture to secure plant reproductive success. Postfertilization growth is perhaps the most dramatic event during fruit morphogenesis. Several studies have proposed that fertilized ovules and developing seeds initiate signaling cascades to coordinate and promote the growth of the accompanying fruit tissues. This dynamic process allows the fruit to conspicuously increase its size and acquire its final shape and means for seed dispersal. All these features are key for plant survival and crop yield. Despite its importance, we lack a high-resolution spatiotemporal map of how postfertilization fruit growth proceeds at the cellular level. In this study, we have combined live imaging, mutant backgrounds in which fertilization can be controlled, and computational modeling to monitor and predict postfertilization fruit growth in Arabidopsis We have uncovered that, unlike leaves, sepals, or roots, fruit do not exhibit a spatial separation of cell division and expansion domains; instead, there is a separation into temporal stages with fertilization as the trigger for transitioning to cell expansion, which drives postfertilization fruit growth. We quantified the coordination between fertilization and fruit growth by imaging no transmitting tract (ntt) mutants, in which fertilization fails in the bottom half of the fruit. By combining our experimental data with computational modeling, we delineated the mobility properties of the seed-derived signaling cascades promoting growth in the fruit. Our study provides the basis for generating a comprehensive understanding of the molecular and cellular mechanisms governing fruit growth and shape.
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Affiliation(s)
- Juan-José Ripoll
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093-0116;
- Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA 92093-0116
| | - Mingyuan Zhu
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Stephanie Brocke
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Cindy T Hon
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093-0116
| | - Martin F Yanofsky
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093-0116
- Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA 92093-0116
| | - Arezki Boudaoud
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, École Normale Supérieur de Lyon, Claud Bernard University Lyon 1, CNRS, Institut National de la Recherche Agronomique, F-69342 Lyon, France
| | - Adrienne H K Roeder
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY 14853;
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
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63
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Santeramo D, Howell J, Ji Y, Yu W, Liu W, Kelliher T. DNA content equivalence in haploid and diploid maize leaves. PLANTA 2019; 251:30. [PMID: 31820114 DOI: 10.1007/s00425-019-03320-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/29/2019] [Indexed: 06/10/2023]
Abstract
The qPCR assay developed to differentiate haploid and diploid maize leaf samples was unsuccessful due to DNA content difference. Haploid cells are packed more closely together with less cellular expansion. Increased ploidy content (> 2 N) directly correlates with increased cell size in plants, but few studies have examined cell morphology in plants with reduced ploidy (i.e., haploids). To pioneer a scalable new ploidy test, we compared DNA content and cellular morphology of haploid and diploid maize leaves. The amount of genomic DNA recovered from standardized leaf-punch samples was equivalent between these two ploidy types, while both epidermal and mesophyll cell types were smaller in haploid plants. Pavement cells had a substantially smaller size than mesophyll cells, and this effect was more pronounced in the abaxial epidermis. Interveinal distance and guard cell size were significantly reduced in haploids, but the cell percentage comprising stomata did not change. These results confirm the direct correlation between ploidy content and cell size in plants, and suggest that reduced cell expansion predominantly explains DNA content equivalence between haploid and diploid samples, confounding efforts to develop a haploid detection method using DNA content.
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Affiliation(s)
- D Santeramo
- Seeds Research, Syngenta Crop Protection, LLC, Research Triangle Park, Durham, NC, USA.
| | - J Howell
- Seeds Research, Syngenta Crop Protection, LLC, Research Triangle Park, Durham, NC, USA
- Pairwise Plants, Research Triangle Park, Durham, NC, USA
| | - Y Ji
- Seeds Research, Syngenta Crop Protection, LLC, Research Triangle Park, Durham, NC, USA
| | - W Yu
- Seeds Research, Syngenta Crop Protection, LLC, Research Triangle Park, Durham, NC, USA
| | - W Liu
- Seeds Research, Syngenta Crop Protection, LLC, Research Triangle Park, Durham, NC, USA
| | - T Kelliher
- Seeds Research, Syngenta Crop Protection, LLC, Research Triangle Park, Durham, NC, USA
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64
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Osmotic Treatment for Quantifying Cell Wall Elasticity in the Sepal of Arabidopsis thaliana. Methods Mol Biol 2019; 2094:101-112. [PMID: 31797295 DOI: 10.1007/978-1-0716-0183-9_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Elastic properties of the cell wall play a key role in regulating plant growth and morphogenesis; however, measuring them in vivo remains a challenge. Although several new methods have recently become available, they all have substantial drawbacks. Here we describe a detailed protocol for osmotic treatments, which is based on the idea of releasing the turgor pressure within the cell and measuring the resulting deformation. When placed in hyperosmotic solution, cells lose water via osmosis and shrink. Confocal images of the tissue, taken before and after this treatment, are quantified using high-resolution surface projections in MorphoGraphX. The cell shrinkage observed can then be used to estimate cell wall elasticity. This allows qualitative comparisons of cell wall properties within organs or between genotypes and can be combined with mechanical simulations to give quantitative estimates of the cells' Young's moduli. We use the abaxial sepal of Arabidopsis thaliana as an easily accessible model system to present our approach, but it can potentially be used on many other plant organs. The main challenges of this technique are choosing the optimal concentration of the hyperosmotic solution and producing high-quality confocal images (with cell walls visualized) good enough for segmentation in MorphoGraphX.
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65
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Abstract
The genetic control of the characteristic cell sizes of different species and tissues is a long-standing enigma. Plants are convenient for studying this question in a multicellular context, as their cells do not move and are easily tracked and measured from organ initiation in the meristems to subsequent morphogenesis and differentiation. In this article, we discuss cell size control in plants compared with other organisms. As seen from yeast cells to mammalian cells, size homeostasis is maintained cell autonomously in the shoot meristem. In developing organs, vacuolization contributes to cell size heterogeneity and may resolve conflicts between growth control at the cellular and organ levels. Molecular mechanisms for cell size control have implications for how cell size responds to changes in ploidy, which are particularly important in plant development and evolution. We also discuss comparatively the functional consequences of cell size and their potential repercussions at higher scales, including genome evolution.
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Affiliation(s)
- Marco D'Ario
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Robert Sablowski
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
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66
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Jones AR, Band LR, Murray JAH. Double or Nothing? Cell Division and Cell Size Control. TRENDS IN PLANT SCIENCE 2019; 24:1083-1093. [PMID: 31630972 DOI: 10.1016/j.tplants.2019.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/08/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Size is a fundamental property that must be tightly regulated to ensure that cells and tissues function efficiently. Dynamic size control allows unicellular organisms to adapt to environmental changes, but cell size is also integral to multicellular development, affecting tissue size and structure. Despite clear evidence for homeostatic cell size maintenance, we are only now beginning to understand cell size regulation in the actively dividing meristematic tissues of higher plants. We discuss here how coupled advances in live cell imaging and modelling are uncovering dynamic mechanisms for size control mediated at the cellular level. We argue that integrated models of cell growth and division will be necessary to predict cell size and fully understand multicellular growth and development.
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Affiliation(s)
- Angharad R Jones
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
| | - Leah R Band
- Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington LE12 5RD, UK; Centre for Mathematical Medicine and Biology, School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - James A H Murray
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK
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67
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Baldazzi V, Valsesia P, Génard M, Bertin N. Organ-wide and ploidy-dependent regulation both contribute to cell-size determination: evidence from a computational model of tomato fruit. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6215-6228. [PMID: 31504751 PMCID: PMC6859726 DOI: 10.1093/jxb/erz398] [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: 01/15/2019] [Accepted: 08/01/2019] [Indexed: 05/10/2023]
Abstract
The development of a new organ is the result of coordinated events of cell division and expansion, in strong interaction with each other. This study presents a dynamic model of tomato fruit development that includes cell division, endoreduplication, and expansion processes. The model is used to investigate the potential interactions among these developmental processes within the context of the neo-cellular theory. In particular, different control schemes (either cell-autonomous or organ-controlled) are tested and compared to experimental data from two contrasting genotypes. The model shows that a pure cell-autonomous control fails to reproduce the observed cell-size distribution, and that an organ-wide control is required in order to get realistic cell-size variations. The model also supports the role of endoreduplication as an important determinant of the final cell size and suggests that a direct effect of endoreduplication on cell expansion is needed in order to obtain a significant correlation between size and ploidy, as observed in real data.
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Affiliation(s)
- Valentina Baldazzi
- INRA, PSH, 228 route de l'Aerodrome, Avignon, France
- Université Côte d'Azur, INRA, CNRS, ISA, 400 route des Chappes, Sophia-Antipolis, France
- Université Côte d'Azur, Inria, INRA, CNRS, Sorbonne Université, BIOCORE, 2004 route des Lucioles, Sophia-Antipolis, France
| | | | - Michel Génard
- INRA, PSH, 228 route de l'Aerodrome, Avignon, France
| | - Nadia Bertin
- INRA, PSH, 228 route de l'Aerodrome, Avignon, France
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68
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Hoshino R, Yoshida Y, Tsukaya H. Multiple steps of leaf thickening during sun-leaf formation in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:738-753. [PMID: 31350790 PMCID: PMC6900135 DOI: 10.1111/tpj.14467] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/09/2019] [Accepted: 07/12/2019] [Indexed: 05/20/2023]
Abstract
Plant morphological and physiological traits exhibit plasticity in response to light intensity. Leaf thickness is enhanced under high light (HL) conditions compared with low light (LL) conditions through increases in both cell number and size in the dorsoventral direction; however, the regulation of such phenotypic plasticity in leaf thickness (namely, sun- or shade-leaf formation) during the developmental process remains largely unclear. By modifying observation techniques for tiny leaf primordia in Arabidopsis thaliana, we analysed sun- and shade-leaf development in a time-course manner and found that the process of leaf thickening can be divided into early and late phases. In the early phase, anisotropic cell elongation and periclinal cell division on the adaxial side of mesophyll tissue occurred under the HL conditions used, which resulted in the dorsoventral growth of sun leaves. Anisotropic cell elongation in the palisade tissue is triggered by blue-light irradiation. We discovered that anisotropic cell elongation processes before or after periclinal cell division were differentially regulated independent of or dependent upon signalling through blue-light receptors. In contrast, during the late phase, isotropic cell expansion associated with the endocycle, which determined the final leaf thickness, occurred irrespective of the light conditions. Sucrose production was high under HL conditions, and we found that sucrose promoted isotropic cell expansion and the endocycle even under LL conditions. Our analyses based on this method of time-course observation addressed the developmental framework of sun- and shade-leaf formation.
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Affiliation(s)
- Rina Hoshino
- Department of Biological SciencesGraduate School of ScienceThe University of TokyoBunkyo‐kuTokyo113‐0033Japan
| | - Yuki Yoshida
- Department of Biological SciencesGraduate School of ScienceThe University of TokyoBunkyo‐kuTokyo113‐0033Japan
| | - Hirokazu Tsukaya
- Department of Biological SciencesGraduate School of ScienceThe University of TokyoBunkyo‐kuTokyo113‐0033Japan
- Exploratory Research Center on Life and Living SystemsNational Institutes of Natural SciencesOkazakiAichi444‐8787Japan
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69
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Bhosale R, Maere S, De Veylder L. Endoreplication as a potential driver of cell wall modifications. CURRENT OPINION IN PLANT BIOLOGY 2019; 51:58-65. [PMID: 31071565 DOI: 10.1016/j.pbi.2019.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 05/06/2023]
Abstract
Endoreplication represents a variant of the mitotic cell cycle during which cells replicate their DNA without mitosis and/or cytokinesis, resulting in an increase in the cells' ploidy level. This process is especially prominent in higher plants, where it has been correlated with cell differentiation, metabolic output and rapid cell growth. However, different reports argue against a ploidy-dependent contribution to cell growth. Here, we review accumulating data suggesting that endocycle onset might exert an effect on cell growth through transcriptional control of cell wall-modifying genes to drive cell wall changes required to accommodate turgor-driven rapid cell expansion, consistent with the idea that vacuolar expansion rather than a ploidy-driven increase in cellular volume represents the major force driving cell growth.
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Affiliation(s)
- Rahul Bhosale
- Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, United Kingdom; Center for Plant Integrative Biology (CPIB), University of Nottingham, Sutton Bonington, LE12 5RD, United Kingdom
| | - Steven Maere
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, B-9052, Belgium; VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium; Bioinformatics Institute Ghent, Ghent University, B-9052 Ghent, Belgium
| | - Lieven De Veylder
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, B-9052, Belgium; VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium.
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Tsukaya H. Re-examination of the role of endoreduplication on cell-size control in leaves. JOURNAL OF PLANT RESEARCH 2019; 132:571-580. [PMID: 31321606 PMCID: PMC6713683 DOI: 10.1007/s10265-019-01125-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 07/12/2019] [Indexed: 05/09/2023]
Abstract
Many Arabidopsis thaliana genes have been reported to affect plant cell size by regulating the level of endoreduplication, which is a modified cell cycle. However, the role of endoreduplication on the altered cell size in these reports must be reconsidered based on a number of findings. First, not all plant species exhibit endoreduplication, which indicates that endoreduplication-driven cell size regulation is not universal among plants. Second, while ploidy level and cell size are correlated in the epidermal pavement cells of Arabidopsis leaves, the size of mesophyll cells appears to be comparatively uniform regardless of whether there is heterogeneity in the ploidy level. Third, changes in the cell sizes reported in mutant and transgenic Arabidopsis seem to be too large to be solely the result of altered endoreduplication level. Fourth, compensated cell enlargement, which is triggered by a severe decrease in cell proliferation in Arabidopsis leaves, is usually independent of altered endoreduplication. We re-examined the role of endoreduplication on cell-size regulation in Arabidopsis, mainly in leaves, and revealed biases in the previous studies. This paper provides an overview of the work carried out in the past decade, and presents rationale to correct the previous assumptions. Based on the considerations provided in this report, a re-examination of previous reports regarding the roles of mutations and/or transgenes in the regulation of cell size is recommended.
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Affiliation(s)
- Hirokazu Tsukaya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan.
- ExCELLS, National Institutes of Natural Sciences, Okazaki, 444-8787, Japan.
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Landrein B, Ingram G. Connected through the force: mechanical signals in plant development. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3507-3519. [PMID: 30821332 DOI: 10.1093/jxb/erz103] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/12/2019] [Indexed: 05/12/2023]
Abstract
As multicellular organisms, plants acquire characteristic shapes through a complex set of biological processes known as morphogenesis. Biochemical signalling underlies much of development, as it allows cells to acquire specific identities based on their position within tissues and organs. However, as growing physical structures, plants, and their constituent cells, also experience internal and external physical forces that can be perceived and can influence key processes such as growth, polarity, and gene expression. This process, which adds another layer of control to growth and development, has important implications for plant morphogenesis. This review provides an overview of recent research into the role of mechanical signals in plant development and aims to show how mechanical signalling can be used, in concert with biochemical signals, as a cue allowing cells and tissues to coordinate their behaviour and to add robustness to developmental processes.
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Affiliation(s)
- Benoit Landrein
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Ecole Normale Supérieure de Lyon, UCB Lyon 1, CNRS, INRA, Lyon Cedex, France
| | - Gwyneth Ingram
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, Ecole Normale Supérieure de Lyon, UCB Lyon 1, CNRS, INRA, Lyon Cedex, France
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Echevin E, Le Gloanec C, Skowrońska N, Routier-Kierzkowska AL, Burian A, Kierzkowski D. Growth and biomechanics of shoot organs. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3573-3585. [PMID: 31037307 DOI: 10.1093/jxb/erz205] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 04/17/2019] [Indexed: 06/09/2023]
Abstract
Plant organs arise through complex interactions between biological and physical factors that control morphogenesis. While there has been tremendous progress in the understanding of the genetics behind development, we know much less about how mechanical forces control growth in plants. In recent years, new multidisciplinary research combining genetics, live-imaging, physics, and computational modeling has begun to fill this gap by revealing the crucial role of biomechanics in the establishment of plant organs. In this review, we provide an overview of our current understanding of growth during initiation, patterning, and expansion of shoot lateral organs. We discuss how growth is controlled by physical forces, and how mechanical stresses generated during growth can control morphogenesis at the level of both cells and tissues. Understanding the mechanical basis of growth and morphogenesis in plants is in its early days, and many puzzling facts are yet to be deciphered.
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Affiliation(s)
- Emilie Echevin
- Institut de Recherche en Biologie Végétale, Department of Biological Sciences, University of Montreal, Montréal, QC, Canada
| | - Constance Le Gloanec
- Institut de Recherche en Biologie Végétale, Department of Biological Sciences, University of Montreal, Montréal, QC, Canada
| | - Nikolina Skowrońska
- Department of Biophysics and Morphogenesis of Plants, University of Silesia, Jagiellońska, Katowice, Poland
| | - Anne-Lise Routier-Kierzkowska
- Institut de Recherche en Biologie Végétale, Department of Biological Sciences, University of Montreal, Montréal, QC, Canada
| | - Agata Burian
- Department of Biophysics and Morphogenesis of Plants, University of Silesia, Jagiellońska, Katowice, Poland
| | - Daniel Kierzkowski
- Institut de Recherche en Biologie Végétale, Department of Biological Sciences, University of Montreal, Montréal, QC, Canada
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73
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Carotenuto G, Sciascia I, Oddi L, Volpe V, Genre A. Size matters: three methods for estimating nuclear size in mycorrhizal roots of Medicago truncatula by image analysis. BMC PLANT BIOLOGY 2019; 156:265-273. [PMID: 31054574 DOI: 10.1046/j.1469-8137.2002.00508.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
BACKGROUND The intracellular accommodation of arbuscular mycorrhizal (AM) fungi involves a profound molecular reprogramming of the host cell architecture and metabolism, based on the activation of a symbiotic signaling pathway. In analogy with other plant biotrophs, AM fungi are reported to trigger cell cycle reactivation in their host tissues, possibly in support of the enhanced metabolic demand required for the symbiosis. RESULTS We here compare the efficiency of three Fiji/ImageJ image analysis plugins in localizing and quantifying the increase in nuclear size - a hallmark of recursive events of endoreduplication - in M. truncatula roots colonized by the AM fungus Gigaspora margarita. All three approaches proved to be versatile and upgradeable, allowing the investigation of nuclear changes in a complex tissue; 3D Object Counter provided more detailed information than both TrackMate and Round Surface Detector plugins. On this base we challenged 3D Object Counter with two case studies: verifying the lack of endoreduplication-triggering responses in Medicago truncatula mutants with a known non-symbiotic phenotype; and analysing the correlation in space and time between the induction of cortical cell division and endoreduplication upon AM colonization. Both case studies revealed important biological aspects. Mutant phenotype analyses have demonstrated that the knock-out mutation of different key genes in the symbiotic signaling pathway block AM-associated endoreduplication. Furthermore, our data show that cell divisions occur during initial stages of root colonization and are followed by recursive activation of the endocycle in preparation for arbuscule accommodation. CONCLUSIONS In conclusion, our results indicate 3D Object Counter as the best performing Fiji/ImageJ image analysis script in plant root thick sections and its application highlighted endoreduplication as a major feature of the AM pre-penetration response in root cortical cells.
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Affiliation(s)
- Gennaro Carotenuto
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Ivan Sciascia
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Ludovica Oddi
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Veronica Volpe
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Andrea Genre
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy.
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74
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Carotenuto G, Sciascia I, Oddi L, Volpe V, Genre A. Size matters: three methods for estimating nuclear size in mycorrhizal roots of Medicago truncatula by image analysis. BMC PLANT BIOLOGY 2019; 19:180. [PMID: 31054574 PMCID: PMC6500585 DOI: 10.1186/s12870-019-1791-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/18/2019] [Indexed: 05/10/2023]
Abstract
BACKGROUND The intracellular accommodation of arbuscular mycorrhizal (AM) fungi involves a profound molecular reprogramming of the host cell architecture and metabolism, based on the activation of a symbiotic signaling pathway. In analogy with other plant biotrophs, AM fungi are reported to trigger cell cycle reactivation in their host tissues, possibly in support of the enhanced metabolic demand required for the symbiosis. RESULTS We here compare the efficiency of three Fiji/ImageJ image analysis plugins in localizing and quantifying the increase in nuclear size - a hallmark of recursive events of endoreduplication - in M. truncatula roots colonized by the AM fungus Gigaspora margarita. All three approaches proved to be versatile and upgradeable, allowing the investigation of nuclear changes in a complex tissue; 3D Object Counter provided more detailed information than both TrackMate and Round Surface Detector plugins. On this base we challenged 3D Object Counter with two case studies: verifying the lack of endoreduplication-triggering responses in Medicago truncatula mutants with a known non-symbiotic phenotype; and analysing the correlation in space and time between the induction of cortical cell division and endoreduplication upon AM colonization. Both case studies revealed important biological aspects. Mutant phenotype analyses have demonstrated that the knock-out mutation of different key genes in the symbiotic signaling pathway block AM-associated endoreduplication. Furthermore, our data show that cell divisions occur during initial stages of root colonization and are followed by recursive activation of the endocycle in preparation for arbuscule accommodation. CONCLUSIONS In conclusion, our results indicate 3D Object Counter as the best performing Fiji/ImageJ image analysis script in plant root thick sections and its application highlighted endoreduplication as a major feature of the AM pre-penetration response in root cortical cells.
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Affiliation(s)
- Gennaro Carotenuto
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Ivan Sciascia
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Ludovica Oddi
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Veronica Volpe
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy
| | - Andrea Genre
- Department of Life Sciences and Systems Biology, University of Turin, 10125, Torino, Italy.
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75
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Li S, Liu L, Li T, Lan T, Wang Y, Zhang Z, Liu J, Xu S, Zhang X, Zhu J, Xue J, Guo D. The distribution pattern of endopolyploidy in maize. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:1487-1503. [PMID: 30734115 DOI: 10.1007/s00122-019-03294-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 01/24/2019] [Indexed: 05/27/2023]
Abstract
We discovered that endopolyploidization is common in various organs and tissues of maize at different development stages. Endopolyploidy is not specific in maize germplasm populations. Endopolyploidy is caused by DNA endoreplication, a special type of mitosis with normal DNA synthesis and a lack of cell division; it is a common phenomenon and plays an important role in plant development. To systematically study the distribution pattern of endopolyploidy in maize, flow cytometry was used to determine the ploidy by measuring the cycle (C) value in various organs at different developmental stages, in embryos and endosperm during grain development, in roots under stress conditions, and in the roots of 119 inbred lines from two heterotic groups, Shaan A and Shaan B. Endopolyploidy was observed in most organs at various developmental stages except in expanded leaves and filaments. The endosperm showed the highest C value among all organs. During tissue development, the ploidy increased in all organs except the leaves. In addition, the endopolyploidization of the roots was significantly affected by drought stress. Multiple comparisons of the C values of seven subgroups revealed that the distribution of endopolyploidization was not correlated with the population structure. A correlation analysis at the seedling stage showed a positive relationship between the C value and both the length of the whole plant and the length of main root. A genome-wide association study (GWAS) identified a total of 9 significant SNPs associated with endopolyploidy (C value) in maize, and 8 candidate genes that participate in cell cycle regulation and DNA replication were uncovered in 119 maize inbred lines.
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Affiliation(s)
- Silu Li
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Linsan Liu
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Ting Li
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Tianru Lan
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Yahui Wang
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Zhengquan Zhang
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Jianchao Liu
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Shutu Xu
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Xinghua Zhang
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Jianchu Zhu
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Jiquan Xue
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China
| | - Dongwei Guo
- The Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, China.
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Li F, Wang L, Zhang Z, Li T, Feng J, Xu S, Zhang R, Guo D, Xue J. ZmSMR4, a novel cyclin-dependent kinase inhibitor (CKI) gene in maize (Zea mays L.), functions as a key player in plant growth, development and tolerance to abiotic stress. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 280:120-131. [PMID: 30823990 DOI: 10.1016/j.plantsci.2018.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/06/2018] [Accepted: 03/08/2018] [Indexed: 06/09/2023]
Abstract
Endoreduplication is a key cell cycle variant in the developing maize endosperm and has been associated with cell enlargement and dry matter accumulation. Therefore, identification of the key genes associated with endosperm development and endoreduplication would not only lay the groundwork for understanding the biological process of endoreduplication but also be important for maize breeding. Here, we identified 12 putative endoreduplication-related candidate genes as members of the Zea mays L. SIAMESE-RELATED (ZmSMR) gene family and denoted them ZmSMR1-ZmSMR12. Sequence analysis indicated that all the ZmSMR protein sequences exhibited modest sequence similarity to the SIAMESE gene from Arabidopsis. Further analyses suggested that most ZmSMR genes might be associated with the transition from mitosis to endoreduplication because the expression levels of most ZmSMR genes were upregulated in endosperm cells during the phase of switching to an endoreduplication cell cycle. Additionally, the ZmSMRs responded to various abiotic stresses at the transcriptional level. One member of the ZmSMR gene family, the ZmSMR4 (KY946768) gene, was isolated as the first maize endoreduplication-related gene and has been used to develop transgenic Arabidopsis plants. ZmSMR4 was localized to the nucleus and could interact with ZmCDKA and ZmCDKB. Moreover, ZmSMR4 was able to rescue the multicellular trichome phenotype of Arabidopsis sim mutants and enhanced the endoreduplication levels of transgenic Arabidopsis plants. Arabidopsis plants overexpressing ZmSMR4 not only displayed enhanced leaf margin serrations but also showed several interesting breeding phenotypes, such as early blossoming and fuller seeds. Taken together, our data suggest that the ZmSMR4 gene is plant-specific and functions as a key player in the signalling network that controls plant growth, development and responses to abiotic stress by regulating the transition between the mitotic cycle and endoreduplication.
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Affiliation(s)
- Feifei Li
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China
| | - Licheng Wang
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China
| | - Zhengquan Zhang
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China
| | - Ting Li
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China
| | - Jiaojiao Feng
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China
| | - Shutu Xu
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China
| | - Renhe Zhang
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China
| | - Dongwei Guo
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China.
| | - Jiquan Xue
- Key Laboratory of the Biology and Genetic Improvement of Maize in Arid Areas of the Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, China; Maize Engineering and Technology Research Centre of Shaanxi Province, Yangling, Shaanxi, 712100, China.
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77
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Long Y, Boudaoud A. Emergence of robust patterns from local rules during plant development. CURRENT OPINION IN PLANT BIOLOGY 2019; 47:127-137. [PMID: 30577002 DOI: 10.1016/j.pbi.2018.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 11/28/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
The formation of spatial and temporal patterns is an essential component of organismal development. Patterns can be observed on every level from subcellular to organismal and may emerge from local rules that correspond to the interactions between molecules, cells, or tissues. The emergence of robust patterns may seem in contradiction with the prominent heterogeneity at subcellular and cellular scales, however it has become increasingly clear that heterogeneity can be instrumental for pattern formation. Here we review recent examples in plant development, involving genetic regulation, cell arrangement, growth and signal gradient. We discuss how patterns emerge from local rules, whether heterogeneity is stochastic or can be patterned, and whether stochastic noise is amplified or requires filtering for robust patterns to be achieved. We also stress the importance of modelling in investigating such questions.
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Affiliation(s)
- Yuchen Long
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, F-69342, Lyon, France
| | - Arezki Boudaoud
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, F-69342, Lyon, France.
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Kierzkowski D, Routier-Kierzkowska AL. Cellular basis of growth in plants: geometry matters. CURRENT OPINION IN PLANT BIOLOGY 2019; 47:56-63. [PMID: 30308452 DOI: 10.1016/j.pbi.2018.09.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 05/28/2023]
Abstract
The growth of individual cells underlies the development of biological forms. In plants, cells are interconnected by rigid walls, fixing their position with respect to one another and generating mechanical feedbacks between cells. Current research is shedding new light on how plant growth is controlled by physical inputs at the level of individual cells and growing tissues. In this review, we discuss recent progress in our understanding of the cellular basis of growth from a biomechanical perspective. We describe the role of the cell wall and turgor pressure in growth and highlight the often-overlooked role of cell geometry in this process. It is becoming apparent that a combination of experimental and theoretical approaches is required to answer new emerging questions in the biomechanics of plant morphogenesis. We summarise how this multidisciplinary approach brings us closer to a unified understanding of the generation of biological forms in plants.
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Affiliation(s)
- Daniel Kierzkowski
- Plant Science Research Institute, Department of Biological Sciences, University of Montreal, 4101 Sherbrooke Est, Montréal H1X 2B2, QC, Canada
| | - Anne-Lise Routier-Kierzkowska
- Plant Science Research Institute, Department of Biological Sciences, University of Montreal, 4101 Sherbrooke Est, Montréal H1X 2B2, QC, Canada.
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79
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Modulation of tissue growth heterogeneity by responses to mechanical stress. Proc Natl Acad Sci U S A 2019; 116:1940-1945. [PMID: 30674660 DOI: 10.1073/pnas.1815342116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Morphogenesis often yields organs with robust size and shapes, whereas cell growth and deformation feature significant spatiotemporal variability. Here, we investigate whether tissue responses to mechanical signals contribute to resolve this apparent paradox. We built a model of growing tissue made of fiber-like material, which may account for the cytoskeleton, polar cell-cell adhesion, or the extracellular matrix in animals and for the cell wall in plants. We considered the synthesis and remodeling of this material, as well as the modulation of synthesis by isotropic and anisotropic response to mechanical stress. Formally, our model describes an expanding, mechanoresponsive, nematic, and active fluid. We show that mechanical responses buffer localized perturbations, with two possible regimes-hyporesponsive and hyperresponsive-and the transition between the two corresponds to a minimum value of the relaxation time. Whereas robustness of shapes suggests that growth fluctuations are confined to small scales, our model yields growth fluctuations that have long-range correlations. This indicates that growth fluctuations are a significant source of heterogeneity in development. Nevertheless, we find that mechanical responses may dampen such fluctuations, with a specific magnitude of anisotropic response that minimizes heterogeneity of tissue contours. We finally discuss how our predictions might apply to the development of plants and animals. Altogether, our results call for the systematic quantification of fluctuations in growing tissues.
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80
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Tofanelli R, Vijayan A, Scholz S, Schneitz K. Protocol for rapid clearing and staining of fixed Arabidopsis ovules for improved imaging by confocal laser scanning microscopy. PLANT METHODS 2019; 15:120. [PMID: 31673277 PMCID: PMC6814113 DOI: 10.1186/s13007-019-0505-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/17/2019] [Indexed: 05/15/2023]
Abstract
BACKGROUND A salient topic in developmental biology relates to the molecular and genetic mechanisms that underlie tissue morphogenesis. Modern quantitative approaches to this central question frequently involve digital cellular models of the organ or tissue under study. The ovules of the model species Arabidopsis thaliana have long been established as a model system for the study of organogenesis in plants. While ovule development in Arabidopsis can be followed by a variety of different imaging techniques, no experimental strategy presently exists that enables an easy and straightforward investigation of the morphology of internal tissues of the ovule with cellular resolution. RESULTS We developed a protocol for rapid and robust confocal microscopy of fixed Arabidopsis ovules of all stages. The method combines clearing of fixed ovules in ClearSee solution with marking the cell outline using the cell wall stain SCRI Renaissance 2200 and the nuclei with the stain TO-PRO-3 iodide. We further improved the microscopy by employing a homogenous immersion system aimed at minimizing refractive index differences. The method allows complete inspection of the cellular architecture even deep within the ovule. Using the new protocol we were able to generate digital three-dimensional models of ovules of various stages. CONCLUSIONS The protocol enables the quick and reproducible imaging of fixed Arabidopsis ovules of all developmental stages. From the imaging data three-dimensional digital ovule models with cellular resolution can be rapidly generated using image analysis software, for example MorphographX. Such digital models will provide the foundation for a future quantitative analysis of ovule morphogenesis in a model species.
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Affiliation(s)
- Rachele Tofanelli
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Str. 4, 85354 Freising, Germany
| | - Athul Vijayan
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Str. 4, 85354 Freising, Germany
| | - Sebastian Scholz
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Str. 4, 85354 Freising, Germany
- Present Address: EU Research Lab, Technische Hochschule Wildau, 15745 Wildau, Germany
| | - Kay Schneitz
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Str. 4, 85354 Freising, Germany
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81
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Stansell Z, Farnham M, Björkman T. Complex Horticultural Quality Traits in Broccoli Are Illuminated by Evaluation of the Immortal BolTBDH Mapping Population. FRONTIERS IN PLANT SCIENCE 2019; 10:1104. [PMID: 31620146 PMCID: PMC6759917 DOI: 10.3389/fpls.2019.01104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 08/12/2019] [Indexed: 05/19/2023]
Abstract
Improving horticultural quality in regionally adapted broccoli (Brassica oleracea var. italica) and other B. oleracea crops is challenging due to complex genetic control of traits affecting morphology, development, and yield. Mapping horticultural quality traits to genomic loci is an essential step in these improvement efforts. Understanding the mechanisms underlying horticultural quality enables multi-trait marker-assisted selection for improved, resilient, and regionally adapted B. oleracea germplasm. The publicly-available biparental double-haploid BolTBDH mapping population (Chinese kale × broccoli; N = 175) was evaluated for 25 horticultural traits in six trait classes (architecture, biomass, phenology, leaf morphology, floral morphology, and head quality) by multiple quantitative trait loci mapping using 1,881 genotype-by-sequencing derived single nucleotide polymorphisms. The physical locations of 56 single and 41 epistatic quantitative trait locus (QTL) were identified. Four head quality QTL (OQ_C03@57.0, OQ_C04@33.3, OQ_CC08@25.5, and OQ_C09@49.7) explain a cumulative 81.9% of phenotypic variance in the broccoli heading phenotype, contain the FLOWERING LOCUS C (FLC) homologs Bo9g173400 and Bo9g173370, and exhibit epistatic effects. Three key genomic hotspots associated with pleiotropic control of the broccoli heading phenotype were identified. One phenology hotspot reduces days to flowering by 7.0 days and includes an additional FLC homolog Bo3g024250 that does not exhibit epistatic effects with the three horticultural quality hotspots. Strong candidates for other horticultural traits were identified: BoLMI1 (Bo3g002560) associated with serrated leaf margins and leaf apex shape, BoCCD4 (Bo3g158650) implicated in flower color, and BoAP2 (Bo1g004960) implicated in the hooked sepal horticultural trait. The BolTBDH population provides a framework for B. oleracea improvement by targeting key genomic loci contributing to high horticultural quality broccoli and enabling de novo mapping of currently unexplored traits.
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Affiliation(s)
- Zachary Stansell
- School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
- Cornell Agritech, Cornell University, Geneva, NY, United States
- *Correspondence: Zachary Stansell,
| | - Mark Farnham
- USDA-ARS Vegetable Laboratory, Department of Horticulture, Charleston, SC, United States
| | - Thomas Björkman
- School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
- Cornell Agritech, Cornell University, Geneva, NY, United States
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82
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Koch G, Rolland G, Dauzat M, Bédiée A, Baldazzi V, Bertin N, Guédon Y, Granier C. Are compound leaves more complex than simple ones? A multi-scale analysis. ANNALS OF BOTANY 2018; 122:1173-1185. [PMID: 29982438 PMCID: PMC6324747 DOI: 10.1093/aob/mcy116] [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: 02/08/2018] [Accepted: 06/06/2018] [Indexed: 06/08/2023]
Abstract
Background and Aims The question of which cellular mechanisms determine the variation in leaf size has been addressed mainly in plants with simple leaves. It is addressed here in tomato taking into consideration the expected complexity added by the several lateral appendages making up the compound leaf, the leaflets. Methods Leaf and leaflet areas, epidermal cell number and areas, and endoreduplication (co-) variations were analysed in Solanum lycopersicum considering heteroblastic series in a wild type (Wva106) and an antisense mutant, the Pro35S:Slccs52AAS line, and upon drought treatments. All plants were grown in an automated phenotyping platform, PHENOPSIS, adapted to host plants grown in 7 L pots. Key Results Leaf area, leaflet area and cell number increased with leaf rank until reaching a plateau. In contrast, cell area slightly decreased and endoreduplication did not follow any trend. In the transgenic line, leaf area, leaflet areas and cell number of basal leaves were lower than in the wild type, but higher in upper leaves. Reciprocally, cell area was higher in basal leaves and lower in upper leaves. When scaled up at the whole sympodial unit, all these traits did not differ significantly between the transgenic line and the wild type. In response to drought, leaf area was reduced, with a clear dose effect that was also reported for all size-related traits, including endoreduplication. Conclusions These results provide evidence that all leaflets have the same cellular phenotypes as the leaf they belong to. Consistent with results reported for simple leaves, they show that cell number rather than cell size determines the final leaf areas and that endoreduplication can be uncoupled from leaf and cell sizes. Finally, they re-question a whole-plant control of cell division and expansion in leaves when the Wva106 and the Pro35S:Slccs52AAS lines are compared.
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Affiliation(s)
- Garance Koch
- LEPSE, Université de Montpellier, INRA, Montpellier SupAgro, Montpellier, France
- INRA, UR PSH, Avignon, France
| | - Gaëlle Rolland
- LEPSE, Université de Montpellier, INRA, Montpellier SupAgro, Montpellier, France
| | - Myriam Dauzat
- LEPSE, Université de Montpellier, INRA, Montpellier SupAgro, Montpellier, France
| | - Alexis Bédiée
- LEPSE, Université de Montpellier, INRA, Montpellier SupAgro, Montpellier, France
| | - Valentina Baldazzi
- INRA, UR PSH, Avignon, France
- ISA, INRA, CNRS, Université Côte d’Azur, France
- BIOCORE, Inria, INRA, CNRS, UPMC Université de Paris 06, Université Côte d’Azur, France
| | | | - Yann Guédon
- AGAP, Université de Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Christine Granier
- LEPSE, Université de Montpellier, INRA, Montpellier SupAgro, Montpellier, France
- AGAP, Université de Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
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83
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Spatiotemporal coordination of cell division and growth during organ morphogenesis. PLoS Biol 2018; 16:e2005952. [PMID: 30383040 PMCID: PMC6211367 DOI: 10.1371/journal.pbio.2005952] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 09/20/2018] [Indexed: 11/30/2022] Open
Abstract
A developing plant organ exhibits complex spatiotemporal patterns of growth, cell division, cell size, cell shape, and organ shape. Explaining these patterns presents a challenge because of their dynamics and cross-correlations, which can make it difficult to disentangle causes from effects. To address these problems, we used live imaging to determine the spatiotemporal patterns of leaf growth and division in different genetic and tissue contexts. In the simplifying background of the speechless (spch) mutant, which lacks stomatal lineages, the epidermal cell layer exhibits defined patterns of division, cell size, cell shape, and growth along the proximodistal and mediolateral axes. The patterns and correlations are distinctive from those observed in the connected subepidermal layer and also different from the epidermal layer of wild type. Through computational modelling we show that the results can be accounted for by a dual control model in which spatiotemporal control operates on both growth and cell division, with cross-connections between them. The interactions between resulting growth and division patterns lead to a dynamic distributions of cell sizes and shapes within a deforming leaf. By modulating parameters of the model, we illustrate how phenotypes with correlated changes in cell size, cell number, and organ size may be generated. The model thus provides an integrated view of growth and division that can act as a framework for further experimental study. Organ morphogenesis involves two coordinated processes: growth of tissue and increase in cell number through cell division. Both processes have been analysed individually in many systems and shown to exhibit complex patterns in space and time. However, it is unclear how these patterns of growth and cell division are coordinated in a growing leaf that is undergoing shape changes. We have addressed this problem using live imaging to track growth and cell division in the developing leaf of the mustard plant Arabidopsis thaliana. Using subsequent computational modelling, we propose an integrated model of leaf growth and cell division, which generates dynamic distributions of cell size and shape in different tissue layers, closely matching those observed experimentally. A key aspect of the model is dual control of spatiotemporal patterns of growth and cell division parameters. By modulating parameters in the model, we illustrate how phenotypes may correlate with changes in cell size, cell number, and organ size.
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84
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Vatén A, Soyars CL, Tarr PT, Nimchuk ZL, Bergmann DC. Modulation of Asymmetric Division Diversity through Cytokinin and SPEECHLESS Regulatory Interactions in the Arabidopsis Stomatal Lineage. Dev Cell 2018; 47:53-66.e5. [PMID: 30197241 PMCID: PMC6177308 DOI: 10.1016/j.devcel.2018.08.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 06/06/2018] [Accepted: 08/08/2018] [Indexed: 11/18/2022]
Abstract
Coordinated growth of organs requires communication among cells within and between tissues. In plants, leaf growth is largely dictated by the epidermis; here, asymmetric and self-renewing divisions of the stomatal lineage create two essential cell types-pavement cells and guard cells-in proportions reflecting inputs from local, systemic, and environmental cues. The transcription factor SPEECHLESS (SPCH) is the prime regulator of divisions, but whether and how it is influenced by external cues to provide flexible development is enigmatic. Here, we show that the phytohormone cytokinin (CK) can act as an endogenous signal to affect the extent and types of stomatal lineage divisions and forms a regulatory circuit with SPCH. Local domains of low CK signaling are created by SPCH-dependent cell-type-specific activity of two repressive type-A ARABIDOPSIS RESPONSE REGULATORs (ARRs), ARR16 and ARR17, and two secreted peptides, CLE9 and CLE10, which, together with SPCH, can customize epidermal cell-type composition.
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Affiliation(s)
- Anne Vatén
- Department of Biology, Stanford University, Stanford, CA 94305-5020, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305-5020, USA
| | - Cara L Soyars
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA
| | - Paul T Tarr
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Zachary L Nimchuk
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA
| | - Dominique C Bergmann
- Department of Biology, Stanford University, Stanford, CA 94305-5020, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305-5020, USA.
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85
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Robinson DO, Coate JE, Singh A, Hong L, Bush M, Doyle JJ, Roeder AHK. Ploidy and Size at Multiple Scales in the Arabidopsis Sepal. THE PLANT CELL 2018; 30:2308-2329. [PMID: 30143539 PMCID: PMC6241276 DOI: 10.1105/tpc.18.00344] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/10/2018] [Accepted: 08/22/2018] [Indexed: 05/02/2023]
Abstract
Ploidy and size phenomena are observed to be correlated across several biological scales, from subcellular to organismal. Two kinds of ploidy change can affect plants. Whole-genome multiplication increases ploidy in whole plants and is broadly associated with increases in cell and organism size. Endoreduplication increases ploidy in individual cells. Ploidy increase is strongly correlated with increased cell size and nuclear volume. Here, we investigate scaling relationships between ploidy and size by simultaneously quantifying nuclear size, cell size, and organ size in sepals from an isogenic series of diploid, tetraploid, and octoploid Arabidopsis thaliana plants, each of which contains an internal endopolyploidy series. We find that pavement cell size and transcriptome size increase linearly with whole-organism ploidy, but organ area increases more modestly due to a compensatory decrease in cell number. We observe that cell size and nuclear size are maintained at a constant ratio; the value of this constant is similar in diploid and tetraploid plants and slightly lower in octoploid plants. However, cell size is maintained in a mutant with reduced nuclear size, indicating that cell size is scaled to cell ploidy rather than to nuclear size. These results shed light on how size is regulated in plants and how cells and organisms of differing sizes are generated by ploidy change.
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Affiliation(s)
- Dana O Robinson
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, New York 14853
| | - Jeremy E Coate
- Department of Biology, Reed College, Portland, Oregon 97202
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, Biomedical Engineering, University of Delaware, Newark, Delaware 19716
| | - Lilan Hong
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, New York 14853
| | - Max Bush
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jeff J Doyle
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, New York 14853
- School of Integrative Plant Science, Section of Plant Breeding and Genetics, Cornell University, Ithaca, New York 14853
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853
- School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, New York 14853
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86
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Bhosale R, Boudolf V, Cuevas F, Lu R, Eekhout T, Hu Z, Van Isterdael G, Lambert GM, Xu F, Nowack MK, Smith RS, Vercauteren I, De Rycke R, Storme V, Beeckman T, Larkin JC, Kremer A, Höfte H, Galbraith DW, Kumpf RP, Maere S, De Veylder L. A Spatiotemporal DNA Endoploidy Map of the Arabidopsis Root Reveals Roles for the Endocycle in Root Development and Stress Adaptation. THE PLANT CELL 2018; 30:2330-2351. [PMID: 30115738 PMCID: PMC6241279 DOI: 10.1105/tpc.17.00983] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 06/18/2018] [Accepted: 08/08/2018] [Indexed: 05/21/2023]
Abstract
Somatic polyploidy caused by endoreplication is observed in arthropods, molluscs, and vertebrates but is especially prominent in higher plants, where it has been postulated to be essential for cell growth and fate maintenance. However, a comprehensive understanding of the physiological significance of plant endopolyploidy has remained elusive. Here, we modeled and experimentally verified a high-resolution DNA endoploidy map of the developing Arabidopsis thaliana root, revealing a remarkable spatiotemporal control of DNA endoploidy levels across tissues. Fitting of a simplified model to publicly available data sets profiling root gene expression under various environmental stress conditions suggested that this root endoploidy patterning may be stress-responsive. Furthermore, cellular and transcriptomic analyses revealed that inhibition of endoreplication onset alters the nuclear-to-cellular volume ratio and the expression of cell wall-modifying genes, in correlation with the appearance of cell structural changes. Our data indicate that endopolyploidy might serve to coordinate cell expansion with structural stability and that spatiotemporal endoreplication pattern changes may buffer for stress conditions, which may explain the widespread occurrence of the endocycle in plant species growing in extreme or variable environments.
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Affiliation(s)
- Rahul Bhosale
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, B-9052 Ghent, Belgium
- Center for Plant Integrative Biology, University of Nottingham, Sutton Bonington LE12 5RD, United Kingdom
| | - Veronique Boudolf
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Fabiola Cuevas
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Ran Lu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Thomas Eekhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Zhubing Hu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, 475004 Kaifeng, China
| | - Gert Van Isterdael
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- VIB Flow Core, B-9052 Ghent, Belgium
| | | | - Fan Xu
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Moritz K Nowack
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Richard S Smith
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany
| | - Ilse Vercauteren
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Riet De Rycke
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- VIB Bio Imaging Core, B-9052 Ghent, Belgium
| | - Veronique Storme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Tom Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - John C Larkin
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Anna Kremer
- Center for Plant Integrative Biology, University of Nottingham, Sutton Bonington LE12 5RD, United Kingdom
- VIB Bio Imaging Core, B-9052 Ghent, Belgium
| | - Herman Höfte
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - David W Galbraith
- School of Plant Sciences, University of Arizona, Tucson, Arizona 85721
- Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Robert P Kumpf
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Steven Maere
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, B-9052 Ghent, Belgium
| | - Lieven De Veylder
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
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87
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Kumar N, Dale R, Kemboi D, Zeringue EA, Kato N, Larkin JC. Functional Analysis of Short Linear Motifs in the Plant Cyclin-Dependent Kinase Inhibitor SIAMESE. PLANT PHYSIOLOGY 2018; 177:1569-1579. [PMID: 29903833 PMCID: PMC6084652 DOI: 10.1104/pp.18.00147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/05/2018] [Indexed: 05/26/2023]
Abstract
Endoreplication, a modified cell cycle in which DNA is replicated without subsequent cell division, plays an important but poorly understood role in plant growth and in plant responses to biotic and abiotic stress. The Arabidopsis (Arabidopsis thaliana) SIAMESE (SIM) gene encodes the first identified member of the SIAMESE-RELATED (SMR) family of cyclin-dependent kinase inhibitors. SIM controls endoreplication during trichome development, and sim mutant trichomes divide several times instead of endoreplicating their DNA. The SMR family is defined by several short linear amino acid sequence motifs of largely unknown function, and family members have little sequence similarity to any known protein functional domains. Here, we investigated the roles of the conserved motifs in SIM site-directed Arabidopsis mutants using several functional assays. We identified a potential cyclin-dependent kinase (CDK)-binding site, which bears no resemblance to other known CDK interaction motifs. We also identified a potential site of phosphorylation and two redundant nuclear localization sequences. Surprisingly, the only motif with similarity to the other family of plant CDK inhibitors, the INHIBITOR/INTERACTOR OF CDC2 KINASE/KIP-RELATED PROTEIN proteins, is not required for SIM function in vivo. Because even highly divergent members of the SMR family are able to replace SIM function in Arabidopsis trichomes, it is likely that the results obtained here for SIM will apply to other members of this plant-specific family of CDK inhibitors.
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Affiliation(s)
- Narender Kumar
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Renee Dale
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Daniel Kemboi
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Elizabeth A Zeringue
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Naohiro Kato
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - John C Larkin
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
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88
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Bateman RM, Guy JJ, Rudall PJ, Leitch IJ, Pellicer J, Leitch AR. Evolutionary and functional potential of ploidy increase within individual plants: somatic ploidy mapping of the complex labellum of sexually deceptive bee orchids. ANNALS OF BOTANY 2018; 122:133-150. [PMID: 29672665 PMCID: PMC6025197 DOI: 10.1093/aob/mcy048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 03/15/2018] [Indexed: 05/07/2023]
Abstract
Background and Aims Recent tissue-level observations made indirectly via flow cytometry suggest that endoreplication (duplication of the nuclear genome within the nuclear envelope in the absence of subsequent cell division) is widespread within the plant kingdom. Here, we also directly observe ploidy variation among cells within individual petals, relating size of nucleus to cell micromorphology and (more speculatively) to function. Methods We compared the labella (specialized pollinator-attracting petals) of two European orchid genera: Dactylorhiza has a known predisposition to organismal polyploidy, whereas Ophrys exhibits exceptionally complex epidermal patterning that aids pseudocopulatory pollination. Confocal microscopy using multiple staining techniques allowed us to observe directly both the sizes and the internal structures of individual nuclei across each labellum, while flow cytometry was used to test for progressively partial endoreplication. Key Results In Dactylorhiza, endoreplication was comparatively infrequent, reached only low levels, and appeared randomly located across the labellum, whereas in Ophrys endoreplication was commonplace, being most frequent in large peripheral trichomes. Endoreplicated nuclei reflected both endomitosis and endocycling, the latter reaching the third round of genome doubling (16C) to generate polytene nuclei. All Ophrys individuals studied exhibited progressively partial endoreplication. Conclusions Comparison of the two genera failed to demonstrate the hypothesized pattern of frequent polyploid speciation in genera showing extensive endoreplication. Endoreplication in Ophrys appears more strongly positively correlated with cell size/complexity than with cell location or secretory role. Epigenetic control of gene overexpression by localized induction of endoreplication within individual plant organs may represent a significant component of a plant's developmental programme, contributing substantially to organ plasticity.
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Affiliation(s)
| | - Jessica J Guy
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
- School of Biological Sciences, University of Reading, Reading, UK
| | - Paula J Rudall
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK
| | - Ilia J Leitch
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK
| | - Jaume Pellicer
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK
| | - Andrew R Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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89
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Hong L, Dumond M, Zhu M, Tsugawa S, Li CB, Boudaoud A, Hamant O, Roeder AHK. Heterogeneity and Robustness in Plant Morphogenesis: From Cells to Organs. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:469-495. [PMID: 29505739 DOI: 10.1146/annurev-arplant-042817-040517] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Development is remarkably reproducible, producing organs with the same size, shape, and function repeatedly from individual to individual. For example, every flower on the Antirrhinum stalk has the same snapping dragon mouth. This reproducibility has allowed taxonomists to classify plants and animals according to their morphology. Yet these reproducible organs are composed of highly variable cells. For example, neighboring cells grow at different rates in Arabidopsis leaves, sepals, and shoot apical meristems. This cellular variability occurs in normal, wild-type organisms, indicating that cellular heterogeneity (or diversity in a characteristic such as growth rate) is either actively maintained or, at a minimum, not entirely suppressed. In fact, cellular heterogeneity can contribute to producing invariant organs. Here, we focus on how plant organs are reproducibly created during development from these highly variable cells.
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Affiliation(s)
- Lilan Hong
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Science; Cornell University, Ithaca, New York 14853, USA; , ,
| | - Mathilde Dumond
- Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, INRA, CNRS, 69364 Lyon CEDEX 07, France; , ,
- Current affiliation: Department for Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland;
| | - Mingyuan Zhu
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Science; Cornell University, Ithaca, New York 14853, USA; , ,
| | - Satoru Tsugawa
- Theoretical Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan;
| | - Chun-Biu Li
- Department of Mathematics, Stockholm University, 106 91 Stockholm, Sweden;
| | - Arezki Boudaoud
- Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, INRA, CNRS, 69364 Lyon CEDEX 07, France; , ,
| | - Olivier Hamant
- Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, INRA, CNRS, 69364 Lyon CEDEX 07, France; , ,
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Science; Cornell University, Ithaca, New York 14853, USA; , ,
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90
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Lau OS, Song Z, Zhou Z, Davies KA, Chang J, Yang X, Wang S, Lucyshyn D, Tay IHZ, Wigge PA, Bergmann DC. Direct Control of SPEECHLESS by PIF4 in the High-Temperature Response of Stomatal Development. Curr Biol 2018; 28:1273-1280.e3. [PMID: 29628371 DOI: 10.1016/j.cub.2018.02.054] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/12/2018] [Accepted: 02/20/2018] [Indexed: 11/18/2022]
Abstract
Environmental factors shape the phenotypes of multicellular organisms. The production of stomata-the epidermal pores required for gas exchange in plants-is highly plastic and provides a powerful platform to address environmental influence on cell differentiation [1-3]. Rising temperatures are already impacting plant growth, a trend expected to worsen in the near future [4]. High temperature inhibits stomatal production, but the underlying mechanism is not known [5]. Here, we show that elevated temperature suppresses the expression of SPEECHLESS (SPCH), the basic-helix-loop-helix (bHLH) transcription factor that serves as the master regulator of stomatal lineage initiation [6, 7]. Our genetic and expression analyses indicate that the suppression of SPCH and stomatal production is mediated by the bHLH transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), a core component of high-temperature signaling [8]. Importantly, we demonstrate that, upon exposure to high temperature, PIF4 accumulates in the stomatal precursors and binds to the promoter of SPCH. In addition, we find SPCH feeds back negatively to the PIF4 gene. We propose a model where warm-temperature-activated PIF4 binds and represses SPCH expression to restrict stomatal production at elevated temperatures. Our work identifies a molecular link connecting high-temperature signaling and stomatal development and reveals a direct mechanism by which production of a specific cell lineage can be controlled by a broadly expressed environmental signaling factor.
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Affiliation(s)
- On Sun Lau
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore; Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Zhuojun Song
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Zimin Zhou
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Kelli A Davies
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Jessica Chang
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Xin Yang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Shenqi Wang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Doris Lucyshyn
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Irene Hui Zhuang Tay
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Philip A Wigge
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK; Sainsbury Laboratory, University of Cambridge, 47 Bateman Street, Cambridge CB2 1LR, UK
| | - Dominique C Bergmann
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
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91
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Dubois M, Selden K, Bediée A, Rolland G, Baumberger N, Noir S, Bach L, Lamy G, Granier C, Genschik P. SIAMESE-RELATED1 Is Regulated Posttranslationally and Participates in Repression of Leaf Growth under Moderate Drought. PLANT PHYSIOLOGY 2018; 176:2834-2850. [PMID: 29472278 PMCID: PMC5884595 DOI: 10.1104/pp.17.01712] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 02/10/2018] [Indexed: 05/06/2023]
Abstract
The plant cell cycle is tightly regulated by factors that integrate endogenous cues and environmental signals to adapt plant growth to changing conditions. Under drought, cell division in young leaves is blocked by an active mechanism, reducing the evaporative surface and conserving energy resources. The molecular function of cyclin-dependent kinase-inhibitory proteins (CKIs) in regulating the cell cycle has already been well studied, but little is known about their involvement in cell cycle regulation under adverse growth conditions. In this study, we show that the transcript of the CKI gene SIAMESE-RELATED1 (SMR1) is quickly induced under moderate drought in young Arabidopsis (Arabidopsis thaliana) leaves. Functional characterization further revealed that SMR1 inhibits cell division and affects meristem activity, thereby restricting the growth of leaves and roots. Moreover, we demonstrate that SMR1 is a short-lived protein that is degraded by the 26S proteasome after being ubiquitinated by a Cullin-RING E3 ubiquitin ligase. Consequently, overexpression of a more stable variant of the SMR1 protein leads to a much stronger phenotype than overexpression of the native SMR1. Under moderate drought, both the SMR1 transcript and SMR1 protein accumulate. Despite this induction, smr1 mutants do not show overall tolerance to drought stress but do show less growth inhibition of young leaves under drought. Surprisingly, the growth-repressive hormone ethylene promotes SMR1 induction, but the classical drought hormone abscisic acid does not.
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Affiliation(s)
- Marieke Dubois
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, Conventionné avec l'Université de Strasbourg, 67084 Strasbourg, France
| | - Katia Selden
- Biochimie et Physiologie Moléculaire des Plantes, Université de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Montpellier SupAgro, 34060 Montpellier, France
| | - Alexis Bediée
- Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux, Université de Montpellier, Institut National de la Recherche Agronomique, Montpellier SupAgro, 34060 Montpellier, France
| | - Gaëlle Rolland
- Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux, Université de Montpellier, Institut National de la Recherche Agronomique, Montpellier SupAgro, 34060 Montpellier, France
| | - Nicolas Baumberger
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, Conventionné avec l'Université de Strasbourg, 67084 Strasbourg, France
| | - Sandra Noir
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, Conventionné avec l'Université de Strasbourg, 67084 Strasbourg, France
| | - Lien Bach
- Biochimie et Physiologie Moléculaire des Plantes, Université de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Montpellier SupAgro, 34060 Montpellier, France
| | - Geneviève Lamy
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, Conventionné avec l'Université de Strasbourg, 67084 Strasbourg, France
| | - Christine Granier
- Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux, Université de Montpellier, Institut National de la Recherche Agronomique, Montpellier SupAgro, 34060 Montpellier, France
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, Conventionné avec l'Université de Strasbourg, 67084 Strasbourg, France
- Biochimie et Physiologie Moléculaire des Plantes, Université de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Montpellier SupAgro, 34060 Montpellier, France
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92
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Weimer AK, Matos JL, Sharma N, Patell F, Murray JAH, Dewitte W, Bergmann DC. Lineage- and stage-specific expressed CYCD7;1 coordinates the single symmetric division that creates stomatal guard cells. Development 2018; 145:dev.160671. [PMID: 29467245 DOI: 10.1242/dev.160671] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/13/2018] [Indexed: 11/20/2022]
Abstract
Plants, with cells fixed in place by rigid walls, often utilize spatial and temporally distinct cell division programs to organize and maintain organs. This leads to the question of how developmental regulators interact with the cell cycle machinery to link cell division events with particular developmental trajectories. In Arabidopsis leaves, the development of stomata, two-celled epidermal valves that mediate plant-atmosphere gas exchange, relies on a series of oriented stem cell-like asymmetric divisions followed by a single symmetric division. The stomatal lineage is embedded in a tissue in which other cells transition from proliferation to postmitotic differentiation earlier, necessitating stomatal lineage-specific factors to prolong competence to divide. We show that the D-type cyclin, CYCD7;1, is specifically expressed just prior to the symmetric guard cell-forming division, and that it is limiting for this division. Further, we find that CYCD7;1 is capable of promoting divisions in multiple contexts, likely through RBR1-dependent promotion of the G1/S transition, but that CYCD7;1 is regulated at the transcriptional level by cell type-specific transcription factors that confine its expression to the appropriate developmental window.
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Affiliation(s)
- Annika K Weimer
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Juliana L Matos
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Nidhi Sharma
- Howard Hughes Medical Institute (HHMI), Stanford University, Stanford, CA 94305, USA
| | - Farah Patell
- Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, UK.,Institute of Biotechnology, University of Cambridge, Cambridge CB2 1QT, UK
| | - James A H Murray
- Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, UK.,Institute of Biotechnology, University of Cambridge, Cambridge CB2 1QT, UK
| | - Walter Dewitte
- Cardiff School of Bioscience, Cardiff University, Cardiff CF10 3AX, UK.,Institute of Biotechnology, University of Cambridge, Cambridge CB2 1QT, UK
| | - Dominique C Bergmann
- Department of Biology, Stanford University, Stanford, CA 94305, USA .,Howard Hughes Medical Institute (HHMI), Stanford University, Stanford, CA 94305, USA
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93
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Coneva V, Chitwood DH. Genetic and Developmental Basis for Increased Leaf Thickness in the Arabidopsis Cvi Ecotype. FRONTIERS IN PLANT SCIENCE 2018; 9:322. [PMID: 29593772 PMCID: PMC5861201 DOI: 10.3389/fpls.2018.00322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 02/27/2018] [Indexed: 05/16/2023]
Abstract
Leaf thickness is a quantitative trait that is associated with the ability of plants to occupy dry, high irradiance environments. Despite its importance, leaf thickness has been difficult to measure reproducibly, which has impeded progress in understanding its genetic basis, and the associated anatomical mechanisms that pattern it. Here, we used a custom-built dual confocal profilometer device to measure leaf thickness in the Arabidopsis Ler × Cvi recombinant inbred line population and found statistical support for four quantitative trait loci (QTL) associated with this trait. We used publically available data for a suite of traits relating to flowering time and growth responses to light quality and show that three of the four leaf thickness QTL coincide with QTL for at least one of these traits. Using time course photography, we quantified the relative growth rate and the pace of rosette leaf initiation in the Ler and Cvi ecotypes. We found that Cvi rosettes grow slower than Ler, both in terms of the rate of leaf initiation and the overall rate of biomass accumulation. Collectively, these data suggest that leaf thickness is tightly linked with physiological status and may present a tradeoff between the ability to withstand stress and rapid vegetative growth. To understand the anatomical basis of leaf thickness, we compared cross-sections of Cvi and Ler leaves and show that Cvi palisade mesophyll cells elongate anisotropically contributing to leaf thickness. Flow cytometry of whole leaves show that endopolyploidy accompanies thicker leaves in Cvi. Overall, our data suggest that mechanistically, an altered schedule of cellular events affecting endopolyploidy and increasing palisade mesophyll cell length contribute to increase of leaf thickness in Cvi. Ultimately, knowledge of the genetic basis and developmental trajectory leaf thickness will inform the mechanisms by which natural selection acts to produce variation in this adaptive trait.
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94
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Roeder AH. Use it or average it: stochasticity in plant development. CURRENT OPINION IN PLANT BIOLOGY 2018; 41:8-15. [PMID: 28837855 DOI: 10.1016/j.pbi.2017.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 07/27/2017] [Accepted: 07/27/2017] [Indexed: 05/21/2023]
Abstract
A process that is stochastic has a probabilistic or randomly determined outcome. At the molecular level, all processes are stochastic; but development is highly reproducible, suggesting that plants and other multicellular organisms have evolved mechanisms to ensure robustness (achieving correct development despite stochastic and environmental perturbations). Mechanisms of robustness can be discovered through isolating mutants with increased variability in phenotype; such mutations do not necessarily change the average phenotype. Surprisingly, some developmental robustness mechanisms actually exploit stochasticity as a useful source of variation. For example, gene expression is stochastic and can be utilized to create subtle differences between identical cells that can initiate the patterning of specialized cell types. Stochasticity can also be used to promote robustness through spatiotemporal averaging-stochasticity can be averaged out across space and over time. Thus, organisms often harness stochasticity to ensure robust development.
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Affiliation(s)
- Adrienne Hk Roeder
- Weill Institute for Cell and Molecular Biology and School of Integrative Plant Science, Section of Plant Biology, Cornell University, 239 Weill Hall, 526 Campus Road, Ithaca, NY 14853, USA.
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95
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Pavelescu I, Vilarrasa-Blasi J, Planas-Riverola A, González-García MP, Caño-Delgado AI, Ibañes M. A Sizer model for cell differentiation in Arabidopsis thaliana root growth. Mol Syst Biol 2018; 14:e7687. [PMID: 29321184 PMCID: PMC5787709 DOI: 10.15252/msb.20177687] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Plant roots grow due to cell division in the meristem and subsequent cell elongation and differentiation, a tightly coordinated process that ensures growth and adaptation to the changing environment. How the newly formed cells decide to stop elongating becoming fully differentiated is not yet understood. To address this question, we established a novel approach that combines the quantitative phenotypic variability of wild‐type Arabidopsis roots with computational data from mathematical models. Our analyses reveal that primary root growth is consistent with a Sizer mechanism, in which cells sense their length and stop elongating when reaching a threshold value. The local expression of brassinosteroid receptors only in the meristem is sufficient to set this value. Analysis of roots insensitive to BR signaling and of roots with gibberellin biosynthesis inhibited suggests distinct roles of these hormones on cell expansion termination. Overall, our study underscores the value of using computational modeling together with quantitative data to understand root growth.
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Affiliation(s)
- Irina Pavelescu
- Department of Molecular Genetics, Center for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra (Cerdanyola del Vallès), Barcelona, Spain.,Departament de Física de la Matèria Condensada, Universitat de Barcelona, Barcelona, Spain
| | - Josep Vilarrasa-Blasi
- Department of Molecular Genetics, Center for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra (Cerdanyola del Vallès), Barcelona, Spain
| | - Ainoa Planas-Riverola
- Department of Molecular Genetics, Center for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra (Cerdanyola del Vallès), Barcelona, Spain
| | - Mary-Paz González-García
- Department of Molecular Genetics, Center for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra (Cerdanyola del Vallès), Barcelona, Spain
| | - Ana I Caño-Delgado
- Department of Molecular Genetics, Center for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra (Cerdanyola del Vallès), Barcelona, Spain
| | - Marta Ibañes
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Barcelona, Spain .,Universitat de Barcelona Institute of Complex Systems (UBICS) Universitat de Barcelona, Barcelona, Spain
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96
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Pirrello J, Deluche C, Frangne N, Gévaudant F, Maza E, Djari A, Bourge M, Renaudin JP, Brown S, Bowler C, Zouine M, Chevalier C, Gonzalez N. Transcriptome profiling of sorted endoreduplicated nuclei from tomato fruits: how the global shift in expression ascribed to DNA ploidy influences RNA-Seq data normalization and interpretation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:387-398. [PMID: 29172253 DOI: 10.1111/tpj.13783] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/09/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
As part of normal development most eukaryotic organisms, ranging from insects and mammals to plants, display variations in nuclear ploidy levels resulting from somatic endopolyploidy. Endoreduplication is the major source of endopolyploidy in higher plants. Endoreduplication is a remarkable characteristic of the fleshy pericarp tissue of developing tomato fruits, where it establishes a highly integrated cellular system that acts as a morphogenetic factor supporting cell growth. However, the functional significance of endoreduplication is not fully understood. Although endoreduplication is thought to increase metabolic activity due to a global increase in transcription, the issue of gene-specific ploidy-regulated transcription remains open. To investigate the influence of endoreduplication on transcription in tomato fruit, we tested the feasibility of a RNA sequencing (RNA-Seq) approach using total nuclear RNA extracted from purified populations of flow cytometry-sorted nuclei based on their DNA content. Here we show that cell-based approaches to the study of RNA-Seq profiles need to take into account the putative global shift in expression between samples for correct analysis and interpretation of the data. From ploidy-specific expression profiles we found that the activity of cells inside the pericarp is related both to the ploidy level and their tissue location.
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Affiliation(s)
- Julien Pirrello
- UMR1332 BFP, INRA, Univ. Bordeaux, 33882, Villenave d'Ornon Cedex, France
- GBF, Université de Toulouse, INRA, 31326, Castanet-Tolosan Cedex, France
| | - Cynthia Deluche
- UMR1332 BFP, INRA, Univ. Bordeaux, 33882, Villenave d'Ornon Cedex, France
| | - Nathalie Frangne
- UMR1332 BFP, INRA, Univ. Bordeaux, 33882, Villenave d'Ornon Cedex, France
| | - Frédéric Gévaudant
- UMR1332 BFP, INRA, Univ. Bordeaux, 33882, Villenave d'Ornon Cedex, France
| | - Elie Maza
- GBF, Université de Toulouse, INRA, 31326, Castanet-Tolosan Cedex, France
| | - Anis Djari
- GBF, Université de Toulouse, INRA, 31326, Castanet-Tolosan Cedex, France
| | - Mickaël Bourge
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | | | - Spencer Brown
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Chris Bowler
- Département de Biologie, IBENS, Ecole Normale Supérieure, CNRS, Inserm, PSL Research University, F-75005, Paris, France
| | - Mohamed Zouine
- GBF, Université de Toulouse, INRA, 31326, Castanet-Tolosan Cedex, France
| | | | - Nathalie Gonzalez
- UMR1332 BFP, INRA, Univ. Bordeaux, 33882, Villenave d'Ornon Cedex, France
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97
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Araújo IS, Pietsch JM, Keizer EM, Greese B, Balkunde R, Fleck C, Hülskamp M. Stochastic gene expression in Arabidopsis thaliana. Nat Commun 2017; 8:2132. [PMID: 29242599 PMCID: PMC5730595 DOI: 10.1038/s41467-017-02285-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/17/2017] [Indexed: 01/29/2023] Open
Abstract
Although plant development is highly reproducible, some stochasticity exists. This developmental stochasticity may be caused by noisy gene expression. Here we analyze the fluctuation of protein expression in Arabidopsis thaliana. Using the photoconvertible KikGR marker, we show that the protein expressions of individual cells fluctuate over time. A dual reporter system was used to study extrinsic and intrinsic noise of marker gene expression. We report that extrinsic noise is higher than intrinsic noise and that extrinsic noise in stomata is clearly lower in comparison to several other tissues/cell types. Finally, we show that cells are coupled with respect to stochastic protein expression in young leaves, hypocotyls and roots but not in mature leaves. Our data indicate that stochasticity of gene expression can vary between tissues/cell types and that it can be coupled in a non-cell-autonomous manner. Noisy gene expression can cause stochasticity in the expression of plant traits. Here, Araújo et al. use a dual reporter system of protein expression in Arabidopsis to show that expression noise is lowest in stomata relative to other tissues and that leaf cells are coupled with respect to noise.
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Affiliation(s)
| | | | - Emma Mathilde Keizer
- Laboratory for Systems and Synthetic Biology, Wageningen University, 6703 HB, Wageningen, The Netherlands
| | - Bettina Greese
- Computational Biology and Biological Physics, Faculty for Theoretical Physics and Astronomy, Lund University, 223 62, Lund, Sweden
| | - Rachappa Balkunde
- Botanical Institute, Biocenter, Cologne University, 50674, Cologne, Germany
| | - Christian Fleck
- Laboratory for Systems and Synthetic Biology, Wageningen University, 6703 HB, Wageningen, The Netherlands.
| | - Martin Hülskamp
- Botanical Institute, Biocenter, Cologne University, 50674, Cologne, Germany.
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98
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Tsugawa S, Hervieux N, Kierzkowski D, Routier-Kierzkowska AL, Sapala A, Hamant O, Smith RS, Roeder AHK, Boudaoud A, Li CB. Clones of cells switch from reduction to enhancement of size variability in Arabidopsis sepals. Development 2017; 144:4398-4405. [PMID: 29183944 PMCID: PMC5769632 DOI: 10.1242/dev.153999] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 10/20/2017] [Indexed: 12/16/2022]
Abstract
Organs form with remarkably consistent sizes and shapes during development, whereas a high variability in growth is observed at the cell level. Given this contrast, it is unclear how such consistency in organ scale can emerge from cellular behavior. Here, we examine an intermediate scale, the growth of clones of cells in Arabidopsis sepals. Each clone consists of the progeny of a single progenitor cell. At early stages, we find that clones derived from a small progenitor cell grow faster than those derived from a large progenitor cell. This results in a reduction in clone size variability, a phenomenon we refer to as size uniformization. By contrast, at later stages of clone growth, clones change their growth pattern to enhance size variability, when clones derived from larger progenitor cells grow faster than those derived from smaller progenitor cells. Finally, we find that, at early stages, fast growing clones exhibit greater cell growth heterogeneity. Thus, cellular variability in growth might contribute to a decrease in the variability of clones throughout the sepal. Summary: Growth analyses of Arabidopsis sepals identify a tipping point in organ development, at which clones of cells change their growth pattern from size uniformization to size variability enhancement.
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Affiliation(s)
- Satoru Tsugawa
- Theoretical Biology Laboratory, RIKEN, Wako 351-0198, Japan
| | - Nathan Hervieux
- Laboratoire de Reproduction et Développement des Plantes, Universiteé de Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, INRA, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Daniel Kierzkowski
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Köln, Germany
| | - Anne-Lise Routier-Kierzkowska
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Köln, Germany
| | - Aleksandra Sapala
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Köln, Germany
| | - Olivier Hamant
- Laboratoire de Reproduction et Développement des Plantes, Universiteé de Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, INRA, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Richard S Smith
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Köln, Germany
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Arezki Boudaoud
- Laboratoire de Reproduction et Développement des Plantes, Universiteé de Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, INRA, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Chun-Biu Li
- Department of Mathematics, Stockholm University, 106 91 Stockholm, Sweden
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99
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Hervieux N, Tsugawa S, Fruleux A, Dumond M, Routier-Kierzkowska AL, Komatsuzaki T, Boudaoud A, Larkin JC, Smith RS, Li CB, Hamant O. Mechanical Shielding of Rapidly Growing Cells Buffers Growth Heterogeneity and Contributes to Organ Shape Reproducibility. Curr Biol 2017; 27:3468-3479.e4. [DOI: 10.1016/j.cub.2017.10.033] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/06/2017] [Accepted: 10/11/2017] [Indexed: 01/02/2023]
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100
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Kawade K, Tsukaya H. Probing the stochastic property of endoreduplication in cell size determination of Arabidopsis thaliana leaf epidermal tissue. PLoS One 2017; 12:e0185050. [PMID: 28926847 PMCID: PMC5605191 DOI: 10.1371/journal.pone.0185050] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/04/2017] [Indexed: 12/21/2022] Open
Abstract
Cell size distribution is highly reproducible, whereas the size of individual cells often varies greatly within a tissue. This is obvious in a population of Arabidopsis thaliana leaf epidermal cells, which ranged from 1,000 to 10,000 μm2 in size. Endoreduplication is a specialized cell cycle in which nuclear genome size (ploidy) is doubled in the absence of cell division. Although epidermal cells require endoreduplication to enhance cellular expansion, the issue of whether this mechanism is sufficient for explaining cell size distribution remains unclear due to a lack of quantitative understanding linking the occurrence of endoreduplication with cell size diversity. Here, we addressed this question by quantitatively summarizing ploidy profile and cell size distribution using a simple theoretical framework. We first found that endoreduplication dynamics is a Poisson process through cellular maturation. This finding allowed us to construct a mathematical model to predict the time evolution of a ploidy profile with a single rate constant for endoreduplication occurrence in a given time. We reproduced experimentally measured ploidy profile in both wild-type leaf tissue and endoreduplication-related mutants with this analytical solution, further demonstrating the probabilistic property of endoreduplication. We next extended the mathematical model by incorporating the element that cell size is determined according to ploidy level to examine cell size distribution. This analysis revealed that cell size is exponentially enlarged 1.5 times every endoreduplication round. Because this theoretical simulation successfully recapitulated experimentally observed cell size distributions, we concluded that Poissonian endoreduplication dynamics and exponential size-boosting are the sources of the broad cell size distribution in epidermal tissue. More generally, this study contributes to a quantitative understanding whereby stochastic dynamics generate steady-state biological heterogeneity.
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Affiliation(s)
- Kensuke Kawade
- Okazaki Institute for Integrative Bioscience, Okazaki, Aichi, Japan
- National Institute for Basic Biology, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Science, Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan
- * E-mail:
| | - Hirokazu Tsukaya
- Okazaki Institute for Integrative Bioscience, Okazaki, Aichi, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
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