1
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Scarpella E. Leaf Vein Patterning. ANNUAL REVIEW OF PLANT BIOLOGY 2024; 75:377-398. [PMID: 38382907 DOI: 10.1146/annurev-arplant-062923-030348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Leaves form veins whose patterns vary from a single vein running the length of the leaf to networks of staggering complexity where huge numbers of veins connect to other veins at both ends. For the longest time, vein formation was thought to be controlled only by the polar, cell-to-cell transport of the plant hormone auxin; recent evidence suggests that is not so. Instead, it turns out that vein patterning features are best accounted for by a combination of polar auxin transport, facilitated auxin diffusion through plasmodesma intercellular channels, and auxin signal transduction-though the latter's precise contribution remains unclear. Equally unclear remain the sites of auxin production during leaf development, on which that vein patterning mechanism ought to depend. Finally, whether that vein patterning mechanism can account for the variety of vein arrangements found in nature remains unknown. Addressing those questions will be the exciting challenge of future research.
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Affiliation(s)
- Enrico Scarpella
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada;
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2
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Bradamante G. Live Imaging of the Shoot Apical Meristem of Intact, Soil-Grown, Flowering Arabidopsis Plants. Bio Protoc 2024; 14:e5015. [PMID: 38948259 PMCID: PMC11211079 DOI: 10.21769/bioprotoc.5015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/15/2024] [Accepted: 05/20/2024] [Indexed: 07/02/2024] Open
Abstract
All aerial organs in plants originate from the shoot apical meristem, a specialized tissue at the tip of a plant, enclosing a few stem cells. Understanding developmental dynamics within this tissue in relation to internal and external stimuli is of crucial importance. Imaging the meristem at the cellular level beyond very early stages requires the apex to be detached from the plant body, a procedure that does not allow studies in living, intact plants over longer periods. This protocol describes a new confocal microscopy method with the potential to image the shoot apical meristem of an intact, soil-grown, flowering Arabidopsis plant over several days. The setup opens new avenues to study apical stem cells, their interconnection with the whole plant, and their responses to environmental stimuli. Key features • Novel dissection and imaging method of the shoot apical meristem of Arabidopsis. • Procedure performed with intact, soil-grown, flowering plants. • Possibility of long-term live imaging of the shoot apical meristem. • Protocol can be adapted to different plant species.
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Affiliation(s)
- Gabriele Bradamante
- BioOptics Core Facility, Gregor Mendel Institute of Molecular Plant Biology (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
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3
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Ruiz-Bayón A, Cara-Rodríguez C, Sarmiento-Mañús R, Muñoz-Viana R, Lozano FM, Ponce MR, Micol JL. Roles of the Arabidopsis KEULE Gene in Postembryonic Development. Int J Mol Sci 2024; 25:6667. [PMID: 38928373 PMCID: PMC11204279 DOI: 10.3390/ijms25126667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 06/14/2024] [Accepted: 06/16/2024] [Indexed: 06/28/2024] Open
Abstract
Cytokinesis in plant cells begins with the fusion of vesicles that transport cell wall materials to the center of the cell division plane, where the cell plate forms and expands radially until it fuses with the parental cell wall. Vesicle fusion is facilitated by trans-SNARE complexes, with assistance from Sec1/Munc18 (SM) proteins. The SNARE protein KNOLLE and the SM protein KEULE are required for membrane fusion at the cell plate. Due to the crucial function of KEULE, all Arabidopsis (Arabidopsis thaliana) keule mutants identified to date are seedling lethal. Here, we identified the Arabidopsis serrata4-1 (sea4-1) and sea4-2 mutants, which carry recessive, hypomorphic alleles of KEULE. Homozygous sea4-1 and sea4-2 plants are viable and fertile but have smaller rosettes and fewer leaves at bolting than the wild type. Their leaves are serrated, small, and wavy, with a complex venation pattern. The mutant leaves also develop necrotic patches and undergo premature senescence. RNA-seq revealed transcriptome changes likely leading to reduced cell wall integrity and an increase in the unfolded protein response. These findings shed light on the roles of KEULE in postembryonic development, particularly in the patterning of rosette leaves and leaf margins.
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Affiliation(s)
| | | | | | | | | | | | - José Luis Micol
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain; (A.R.-B.); (C.C.-R.); (R.S.-M.); (R.M.-V.); (F.M.L.); (M.R.P.)
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4
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Chen W, Wang P, Liu C, Han Y, Zhao F. Male Germ Cell Specification in Plants. Int J Mol Sci 2024; 25:6643. [PMID: 38928348 PMCID: PMC11204311 DOI: 10.3390/ijms25126643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/06/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Germ cells (GCs) serve as indispensable carriers in both animals and plants, ensuring genetic continuity across generations. While it is generally acknowledged that the timing of germline segregation differs significantly between animals and plants, ongoing debates persist as new evidence continues to emerge. In this review, we delve into studies focusing on male germ cell specifications in plants, and we summarize the core gene regulatory circuits in germ cell specification, which show remarkable parallels to those governing meristem homeostasis. The similarity in germline establishment between animals and plants is also discussed.
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Affiliation(s)
- Wenqian Chen
- Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection, School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710129, China; (W.C.); (P.W.); (C.L.); (Y.H.)
| | - Pan Wang
- Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection, School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710129, China; (W.C.); (P.W.); (C.L.); (Y.H.)
| | - Chan Liu
- Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection, School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710129, China; (W.C.); (P.W.); (C.L.); (Y.H.)
| | - Yuting Han
- Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection, School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710129, China; (W.C.); (P.W.); (C.L.); (Y.H.)
| | - Feng Zhao
- Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection, School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710129, China; (W.C.); (P.W.); (C.L.); (Y.H.)
- Collaborative Innovation Center of Northwestern Polytechnical University, Shanghai 201108, China
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5
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Sessa G, Carabelli M, Sassi M. The Ins and Outs of Homeodomain-Leucine Zipper/Hormone Networks in the Regulation of Plant Development. Int J Mol Sci 2024; 25:5657. [PMID: 38891845 PMCID: PMC11171833 DOI: 10.3390/ijms25115657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/20/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024] Open
Abstract
The generation of complex plant architectures depends on the interactions among different molecular regulatory networks that control the growth of cells within tissues, ultimately shaping the final morphological features of each structure. The regulatory networks underlying tissue growth and overall plant shapes are composed of intricate webs of transcriptional regulators which synergize or compete to regulate the expression of downstream targets. Transcriptional regulation is intimately linked to phytohormone networks as transcription factors (TFs) might act as effectors or regulators of hormone signaling pathways, further enhancing the capacity and flexibility of molecular networks in shaping plant architectures. Here, we focus on homeodomain-leucine zipper (HD-ZIP) proteins, a class of plant-specific transcriptional regulators, and review their molecular connections with hormonal networks in different developmental contexts. We discuss how HD-ZIP proteins emerge as key regulators of hormone action in plants and further highlight the fundamental role that HD-ZIP/hormone networks play in the control of the body plan and plant growth.
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Affiliation(s)
| | | | - Massimiliano Sassi
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, 00185 Rome, Italy; (G.S.); (M.C.)
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6
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Yadav AS, Hong L, Klees PM, Kiss A, Petit M, He X, Barrios IM, Heeney M, Galang AMD, Smith RS, Boudaoud A, Roeder AH. Growth directions and stiffness across cell layers determine whether tissues stay smooth or buckle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.22.549953. [PMID: 37546730 PMCID: PMC10401922 DOI: 10.1101/2023.07.22.549953] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
From smooth to buckled, nature exhibits organs of various shapes and forms. How cellular growth patterns produce smooth organ shapes such as leaves and sepals remains unclear. Here we show that unidirectional growth and comparable stiffness across both epidermal layers of Arabidopsis sepals are essential for smoothness. We identified a mutant with ectopic ASYMMETRIC LEAVES 2 (AS2) expression on the outer epidermis. Our analysis reveals that ectopic AS2 expression causes outer epidermal buckling at early stages of sepal development, due to conflicting growth directions and unequal epidermal stiffnesses. Aligning growth direction and increasing stiffness of the outer epidermis restores smoothness. Furthermore, buckling influences auxin efflux transporter protein PIN-FORMED 1 polarity to generate outgrowth in the later stages, suggesting that buckling is sufficient to initiate outgrowths. Our findings suggest that in addition to molecular cues influencing tissue mechanics, tissue mechanics can also modulate molecular signals, giving rise to well-defined shapes.
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Affiliation(s)
- Avilash S. Yadav
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Lilan Hong
- 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 310058, China
| | - Patrick M. Klees
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Annamaria Kiss
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon1, CNRS, INRAE, INRIA, F-69342 Lyon, France
| | - Manuel Petit
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon1, CNRS, INRAE, INRIA, F-69342 Lyon, France
| | - Xi He
- 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 310058, China
| | - Iselle M. Barrios
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Michelle Heeney
- Weill Institute for Cell and Molecular Biology and Section of Plant Biology, School of Integrative Plant Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Anabella Maria D. Galang
- 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
- LadHyX, Ecole Polytechnique, CNRS, IP Paris, 91128 Palaiseau Cedex, France
| | - 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
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7
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Scacchi E, Paszkiewicz G, Thi Nguyen K, Meda S, Burian A, de Back W, Timmermans MCP. A diffusible small-RNA-based Turing system dynamically coordinates organ polarity. NATURE PLANTS 2024; 10:412-422. [PMID: 38409292 DOI: 10.1038/s41477-024-01634-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 01/26/2024] [Indexed: 02/28/2024]
Abstract
The formation of a flat and thin leaf presents a developmentally challenging problem, requiring intricate regulation of adaxial-abaxial (top-bottom) polarity. The patterning principles controlling the spatial arrangement of these domains during organ growth have remained unclear. Here we show that this regulation in Arabidopsis thaliana is achieved by an organ-autonomous Turing reaction-diffusion system centred on mobile small RNAs. The data illustrate how Turing dynamics transiently instructed by prepatterned information is sufficient to self-sustain properly oriented polarity in a dynamic, growing organ, presenting intriguing parallels to left-right patterning in the vertebrate embryo. Computational modelling demonstrates that this self-organizing system continuously adapts to coordinate the robust planar polarity of a flat leaf while affording flexibility to generate the tissue patterns of evolutionarily diverse organ shapes. Our findings identify a small-RNA-based Turing network as a dynamic regulator of organ polarity that accounts for leaf shape diversity at the level of the individual organ, plant or species.
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Affiliation(s)
- Emanuele Scacchi
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany.
| | - Gael Paszkiewicz
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Khoa Thi Nguyen
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam
| | - Shreyas Meda
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Agata Burian
- Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Katowice, Poland
| | - Walter de Back
- Institute for Medical Informatics and Biometry, Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
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8
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Burda I, Martin AC, Roeder AHK, Collins MA. The dynamics and biophysics of shape formation: Common themes in plant and animal morphogenesis. Dev Cell 2023; 58:2850-2866. [PMID: 38113851 PMCID: PMC10752614 DOI: 10.1016/j.devcel.2023.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 09/19/2023] [Accepted: 11/10/2023] [Indexed: 12/21/2023]
Abstract
The emergence of tissue form in multicellular organisms results from the complex interplay between genetics and physics. In both plants and animals, cells must act in concert to pattern their behaviors. Our understanding of the factors sculpting multicellular form has increased dramatically in the past few decades. From this work, common themes have emerged that connect plant and animal morphogenesis-an exciting connection that solidifies our understanding of the developmental basis of multicellular life. In this review, we will discuss the themes and the underlying principles that connect plant and animal morphogenesis, including the coordination of gene expression, signaling, growth, contraction, and mechanical and geometric feedback.
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Affiliation(s)
- Isabella Burda
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Genetic Genomics and Development Program, Cornell University, Ithaca, NY 14853, USA
| | - Adam C Martin
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Adrienne H K Roeder
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Genetic Genomics and Development Program, Cornell University, Ithaca, NY 14853, USA; School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14850, USA.
| | - Mary Ann Collins
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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9
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Sinha S, Sahadevan S, Ohno C, Ram H, Heisler MG. Global gene regulatory network underlying miR165a in Arabidopsis shoot apical meristem. Sci Rep 2023; 13:22258. [PMID: 38097643 PMCID: PMC10721644 DOI: 10.1038/s41598-023-49093-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 12/04/2023] [Indexed: 12/17/2023] Open
Abstract
Arabidopsis microRNA165a (miR165a) targets Class III Homeodomain Leucine-Zipper (HD-ZIPIII) transcription factors to regulate various aspects of plant development and stress response. Over-expression of miR165a mimics the loss-of-function phenotype of HD-ZIPIII genes and leading to ectopic organ formation, shoot apical meristem (SAM) termination, loss of leaf polarity, and defective vasculature development. However, the molecular mechanisms underlying these phenotypes remain unresolved. Here, we over-expressed miR165a in a dexamethasone inducible manner and identified differentially expressed genes in the SAM through RNA-Seq. Simultaneously, using multi-channel FACS combined with RNA-Seq approach, we characterized global transcriptome patterns in miR165a expressing cell-types compared to HD-ZIPIII expressing cell-types and other cell-types in SAM. By integrating our results we identified sets of genes which are up-regulated by miR165a as well have enriched expression in miR165a cell-types, and vice-versa. Known plant development related genes such as HD-ZIPIII and their targets LITTLE ZIPPERs, Like AUXIN RESISTANT 2, BEL1-like homeodomain 6, ROTUNDIFOLIA like 16 were found to be down-regulated. Among the up-regulated genes, GIBBERELLIN 2-OXIDASEs, various elemental transporters (YSL3, ZIFL1, SULTR), and other transporter genes were prominent. Thus, the genes identified in this study help to unravel the molecular mechanism of miR165a and HD-ZIPIII regulated plant development and stress response.
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Affiliation(s)
- Sonali Sinha
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110067, India
| | - Sudeep Sahadevan
- European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany
| | - Carolyn Ohno
- European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Hasthi Ram
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110067, India.
- European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany.
| | - Marcus G Heisler
- European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany.
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.
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10
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Smith ES, Nimchuk ZL. What a tangled web it weaves: auxin coordination of stem cell maintenance and flower production. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6950-6963. [PMID: 37661937 PMCID: PMC10690728 DOI: 10.1093/jxb/erad340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/25/2023] [Indexed: 09/05/2023]
Abstract
Robust agricultural yields require consistent flower production throughout fluctuating environmental conditions. Floral primordia are produced in the inflorescence meristem, which contains a pool of continuously dividing stem cells. Daughter cells of these divisions either retain stem cell identity or are pushed to the SAM periphery, where they become competent to develop into floral primordia after receiving the appropriate signal. Thus, flower production is inherently linked to regulation of the stem cell pool. The plant hormone auxin promotes flower development throughout its early phases and has been shown to interact with the molecular pathways regulating stem cell maintenance. Here, we will summarize how auxin signaling contributes to stem cell maintenance and promotes flower development through the early phases of initiation, outgrowth, and floral fate establishment. Recent advances in this area suggest that auxin may serve as a signal that integrates stem cell maintenance and new flower production.
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Affiliation(s)
- Elizabeth Sarkel Smith
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Zachary L Nimchuk
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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11
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Choudury SG, Husbands AY. Pick a side: Integrating gene expression and mechanical forces to polarize aerial organs. CURRENT OPINION IN PLANT BIOLOGY 2023; 76:102460. [PMID: 37775406 DOI: 10.1016/j.pbi.2023.102460] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/25/2023] [Accepted: 09/01/2023] [Indexed: 10/01/2023]
Abstract
How organs acquire their shapes is a central question in developmental biology. In plants, aerial lateral organs such as leaves initiate at the flanks of the growing meristem as dome-shaped primordia. These simple structures then grow out along multiple polarity axes to achieve a dizzying array of final shapes. Many of the hormone signaling pathways and genetic interactions that influence growth along these axes have been identified in the past few decades. Open questions include how and when initial gene expression patterns are set in organ primordia, and how these patterns are translated into the physical outcomes observed at the cellular and tissue levels. In this review, we highlight recent studies into the auxin signaling and gene expression dynamics that govern adaxial-abaxial patterning, and the contributions of mechanical forces to the development of flattened structures.
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Affiliation(s)
- Sarah G Choudury
- Department of Biology, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Aman Y Husbands
- Department of Biology, University of Pennsylvania, Philadelphia PA 19104, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia PA 19104, USA.
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12
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Peng Z, Jiao Y, Wang Y. Live imaging of Arabidopsis shoot primordia via a confocal laser scanning microscope. STAR Protoc 2023; 4:102217. [PMID: 37027308 PMCID: PMC10085777 DOI: 10.1016/j.xpro.2023.102217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/06/2023] [Accepted: 03/10/2023] [Indexed: 04/07/2023] Open
Abstract
Live imaging through confocal laser scanning microscopy enables the recording, analysis, and comparison of the dynamics of shapes and gene expression patterns of plant shoot apical meristems (SAMs) or primordia. Here, we provide a protocol to describe the preparation process of imaging Arabidopsis SAMs and primordia using a confocal microscope. We describe steps for dissection, visualization of meristems using dyes and fluorescent proteins, and gain 3D morphology of meristems. We then detail analysis of shoot meristems using time-lapse imaging. For complete details on the use and execution of this protocol, please refer to Peng et al. (2022).1.
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13
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Cheng J, Yao X, Li X, Yue L, Duan X, Li B, Fu X, Li S, Shan H, Yin X, Whitewoods C, Coen E, Kong H. Diversification of ranunculaceous petals in shape supports a generalized model for plant lateral organ morphogenesis and evolution. SCIENCE ADVANCES 2023; 9:eadf8049. [PMID: 37083529 PMCID: PMC10121167 DOI: 10.1126/sciadv.adf8049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Peltate organs, such as the prey-capturing traps of carnivorous plants and nectary-bearing petals of ranunculaceous species, are widespread in nature and have intrigued and perplexed scientists for centuries. Shifts in the expression domains of adaxial/abaxial genes have been shown to control leaf peltation in some carnivorous plants, yet the mechanisms underlying the generation of other peltate organs remain unclear. Here, we show that formation of various peltate ranunculaceous petals was also caused by shifts in the expression domains of adaxial/abaxial genes, followed by differentiated regional growth sculpting the margins and/or other parts of the organs. By inducing parameters to specify the time, position, and degree of the shifts and growth, we further propose a generalized modeling system, through which various unifacial, bifacial, and peltate organs can be simulated. These results demonstrate the existence of a hierarchical morphospace system and pave the way to understand the mechanisms underlying plant organ diversification.
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Affiliation(s)
- Jie Cheng
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Xu Yao
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Xukun Li
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liang Yue
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xiaoshan Duan
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Boka Li
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuehao Fu
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Shuixian Li
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongyan Shan
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Xiaofeng Yin
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | | | - Enrico Coen
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
| | - Hongzhi Kong
- State Key Laboratory of Systematic and Evolutionary Botany, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Corresponding author.
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14
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Morphogenesis of leaves: from initiation to the production of diverse shapes. Biochem Soc Trans 2023; 51:513-525. [PMID: 36876869 DOI: 10.1042/bst20220678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 02/04/2023] [Accepted: 02/16/2023] [Indexed: 03/07/2023]
Abstract
The manner by which plant organs gain their shape is a longstanding question in developmental biology. Leaves, as typical lateral organs, are initiated from the shoot apical meristem that harbors stem cells. Leaf morphogenesis is accompanied by cell proliferation and specification to form the specific 3D shapes, with flattened lamina being the most common. Here, we briefly review the mechanisms controlling leaf initiation and morphogenesis, from periodic initiation in the shoot apex to the formation of conserved thin-blade and divergent leaf shapes. We introduce both regulatory gene patterning and biomechanical regulation involved in leaf morphogenesis. How phenotype is determined by genotype remains largely unanswered. Together, these new insights into leaf morphogenesis resolve molecular chains of events to better aid our understanding.
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15
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Traas J. Morphogenesis at the shoot meristem. C R Biol 2023; 345:129-148. [PMID: 36847122 DOI: 10.5802/crbiol.98] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 11/14/2022] [Indexed: 11/25/2022]
Abstract
Shoot apical meristems are populations of stem cells which initiate the aerial parts of higher plants. Work during the last decades has revealed a complex network of molecular regulators, which control both meristem maintenance and the production of different types of organs. The behavior of this network in time and space is defined by the local interactions between regulators and also involves hormonal regulation. In particular, auxin and cytokinin are intimately implicated in the coordination of gene expression patterns. To control growth patterns at the shoot meristem the individual components of the network influence directions and rates of cell growth. This requires interference with the mechanical properties of the cells. How this complex multiscale process, characterized by multiple feedbacks, is controlled remains largely an open question. Fortunately, genetics, live imaging, computational modelling and a number of other recently developed tools offer interesting albeit challenging perspectives.
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16
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Polar auxin transport modulates early leaf flattening. Proc Natl Acad Sci U S A 2022; 119:e2215569119. [PMID: 36469773 PMCID: PMC9897438 DOI: 10.1073/pnas.2215569119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The flattened leaf form is an important adaptation for efficient photosynthesis, and the developmental process of flattened leaves has been intensively studied. Classic microsurgery studies in potato and tomato suggest that the shoot apical meristem (SAM) communicates with the leaf primordia to promote leaf blade formation. More recently, it was found that polar auxin transport (PAT) could mediate this communication. However, it is unclear how the expression of leaf patterning genes is tailored by PAT routes originating from SAM. By combining experimental observations and computer model simulations, we show that microsurgical incisions and local inhibition of PAT in tomato interfere with auxin transport toward the leaf margins, reducing auxin response levels and altering the leaf blade shape. Importantly, oval auxin responses result in the bipolar expression of SlLAM1 that determines leaf blade formation. Furthermore, wounding caused by incisions promotes degradation of SlREV, a known regulator of leaf polarity. Additionally, computer simulations suggest that local auxin biosynthesis in early leaf primordia could remove necessity for external auxin supply originating from SAM, potentially explaining differences between species. Together, our findings establish how PAT near emerging leaf primordia determines spatial auxin patterning and refines SlLAM1 expression in the leaf margins to guide leaf flattening.
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17
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Guan C, Jiao Y. Spatiotemporal imaging clarifies leaf primordium patterning. TRENDS IN PLANT SCIENCE 2022; 27:1196-1198. [PMID: 36055917 DOI: 10.1016/j.tplants.2022.08.011] [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: 04/26/2022] [Revised: 08/12/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
The first step in organ morphogenesis is the subdivision of a primordium into discrete regions by patterning genes. Recently, Burian et al. used live imaging and cell-lineage tracing to illuminate early patterning events during the establishment of leaf primordium adaxial-abaxial (dorsoventral) polarity, which clarifies controversies in the field.
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Affiliation(s)
- Chunmei Guan
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuling Jiao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Center for Quantitative Biology, Peking University, Beijing 100871, China.
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18
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Nicolas A, Maugarny-Calès A, Adroher B, Chelysheva L, Li Y, Burguet J, Bågman AM, Smit ME, Brady SM, Li Y, Laufs P. De novo stem cell establishment in meristems requires repression of organ boundary cell fate. THE PLANT CELL 2022; 34:4738-4759. [PMID: 36029254 PMCID: PMC9709991 DOI: 10.1093/plcell/koac269] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 08/24/2022] [Indexed: 05/27/2023]
Abstract
Stem cells play important roles in animal and plant biology, as they sustain morphogenesis and tissue replenishment following aging or injury. In plants, stem cells are embedded in multicellular structures called meristems. The formation of new meristems is essential for the plastic expansion of the highly branched shoot and root systems. In particular, axillary meristems (AMs) that produce lateral shoots arise from the division of boundary domain cells at the leaf base. The CUP-SHAPED COTYLEDON (CUC) genes are major determinants of the boundary domain and are required for AM initiation. However, how AMs get structured and how stem cells become established de novo remain elusive. Here, we show that two NGATHA-LIKE (NGAL) transcription factors, DEVELOPMENT-RELATED PcG TARGET IN THE APEX4 (DPA4)/NGAL3 and SUPPRESSOR OF DA1-1 7 (SOD7)/NGAL2, redundantly repress CUC expression in initiating AMs of Arabidopsis thaliana. Ectopic boundary fate leads to abnormal growth and organization of the AM and prevents de novo stem cell establishment. Floral meristems of the dpa4 sod7 double mutant show a similar delay in de novo stem cell establishment. Altogether, while boundary fate is required for the initiation of AMs, our work reveals how it is later repressed to allow proper meristem establishment and de novo stem cell niche formation.
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Affiliation(s)
- Antoine Nicolas
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, 78000, France
- Université Paris-Saclay, Orsay, 91405, France
| | - Aude Maugarny-Calès
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, 78000, France
- Université Paris-Saclay, Orsay, 91405, France
| | - Bernard Adroher
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, 78000, France
| | - Liudmila Chelysheva
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, 78000, France
| | - Yu Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jasmine Burguet
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, 78000, France
| | - Anne-Maarit Bågman
- Department of Plant Biology and Genome Center, University of California, Davis, California 95616, USA
| | - Margot E Smit
- Department of Plant Biology and Genome Center, University of California, Davis, California 95616, USA
| | - Siobhan M Brady
- Department of Plant Biology and Genome Center, University of California, Davis, California 95616, USA
| | - Yunhai Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Patrick Laufs
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, 78000, France
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19
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Peng Z, Alique D, Xiong Y, Hu J, Cao X, Lü S, Long M, Wang Y, Wabnik K, Jiao Y. Differential growth dynamics control aerial organ geometry. Curr Biol 2022; 32:4854-4868.e5. [PMID: 36272403 DOI: 10.1016/j.cub.2022.09.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 07/05/2022] [Accepted: 09/27/2022] [Indexed: 11/22/2022]
Abstract
How gene activities and biomechanics together direct organ shapes is poorly understood. Plant leaf and floral organs develop from highly similar initial structures and share similar gene expression patterns, yet they gain drastically different shapes later-flat and bilateral leaf primordia and radially symmetric floral primordia, respectively. We analyzed cellular growth patterns and gene expression in young leaves and flowers of Arabidopsis thaliana and found significant differences in cell growth rates, which correlate with convergence sites of phytohormone auxin that require polar auxin transport. In leaf primordia, the PRESSED-FLOWER-expressing middle domain grows faster than adjacent adaxial domain and coincides with auxin convergence. In contrast, in floral primordia, the LEAFY-expressing domain shows accelerated growth rates and pronounced auxin convergence. This distinct cell growth dynamics between leaf and flower requires changes in levels of cell-wall pectin de-methyl-esterification and mechanical properties of the cell wall. Data-driven computer model simulations at organ and cellular levels demonstrate that growth differences are central to obtaining distinct organ shape, corroborating in planta observations. Together, our study provides a mechanistic basis for the establishment of early aerial organ symmetries through local modulation of differential growth patterns with auxin and biomechanics.
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Affiliation(s)
- Ziyuan Peng
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daniel Alique
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Centro Nacional Instituto de Investigación y Tecnología Agraria y Alimentaria (INIA, CSIC), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Yuanyuan Xiong
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Jinrong Hu
- Key Laboratory of Microgravity (National Microgravity Laboratory), Center of Biomechanics and Bioengineering, and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiuwei Cao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Shouqin Lü
- Key Laboratory of Microgravity (National Microgravity Laboratory), Center of Biomechanics and Bioengineering, and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mian Long
- Key Laboratory of Microgravity (National Microgravity Laboratory), Center of Biomechanics and Bioengineering, and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Krzysztof Wabnik
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Centro Nacional Instituto de Investigación y Tecnología Agraria y Alimentaria (INIA, CSIC), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain.
| | - Yuling Jiao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Center for Quantitative Biology, Peking University, Beijing 100871, China; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China.
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20
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Alam I, Manghwar H, Zhang H, Yu Q, Ge L. Identification of GOLDEN2-like transcription factor genes in soybeans and their role in regulating plant development and metal ion stresses. FRONTIERS IN PLANT SCIENCE 2022; 13:1052659. [PMID: 36438095 PMCID: PMC9691782 DOI: 10.3389/fpls.2022.1052659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
The Golden 2-Like (G2-like or GLK) transcription factors are essential for plant growth, development, and many stress responses as well as heavy metal stress. However, G2-like regulatory genes have not been studied in soybean. This study identified the genes for 130 G2-Like candidates' in the genome of Glycine max (soybean). These GLK genes were located on all 20 chromosomes, and several of them were segmentally duplicated. Most GLK family proteins are highly conserved in Arabidopsis and soybean and were classified into five major groups based on phylogenetic analysis. These GmGLK gene promoters share cis-acting elements involved in plant responses to abscisic acid, methyl jasmonate, auxin signaling, low temperature, and biotic and abiotic stresses. RNA-seq expression data revealed that the GLK genes were classified into 12 major groups and differentially expressed in different tissues or organs. The co-expression network complex revealed that the GmGLK genes encode proteins involved in the interaction of genes related to chlorophyll biosynthesis, circadian rhythms, and flowering regulation. Real-time quantitative PCR analysis confirmed the expression profiles of eight GLK genes in response to cadmium (Cd) and copper (Cu) stress, with some GLK genes significantly induced by both Cd and Cu stress treatments, implying a functional role in defense responsiveness. Thus, we present a comprehensive perspective of the GLK genes in soybean and emphasize their important role in crop development and metal ion stresses.
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Affiliation(s)
- Intikhab Alam
- Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
- College of Life Sciences, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
- Guangdong Subcenter of the National Center for Soybean Improvement, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
| | - Hakim Manghwar
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
| | - Hanyin Zhang
- Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
- Guangdong Subcenter of the National Center for Soybean Improvement, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
| | - Qianxia Yu
- Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
- Guangdong Subcenter of the National Center for Soybean Improvement, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
| | - Liangfa Ge
- Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
- Guangdong Subcenter of the National Center for Soybean Improvement, South China Agricultural University (SCAU), Guangzhou, Guangdong, China
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21
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Heisler MG, Jönsson H, Wenkel S, Kaufmann K. Context-specific functions of transcription factors controlling plant development: From leaves to flowers. CURRENT OPINION IN PLANT BIOLOGY 2022; 69:102262. [PMID: 35952407 DOI: 10.1016/j.pbi.2022.102262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/14/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Plant development is regulated by transcription factors that often act in more than one process and stage of development. Yet the molecular mechanisms that govern the functional diversity and specificity of these proteins remains far from understood. Flower development provides an ideal context to study these mechanisms since the development of distinct floral organs depends on similar but distinct combinations of transcriptional regulators. Recent work also highlights the importance of leaf polarity regulators as additional key factors in flower initiation, floral organ morphogenesis, and possibly floral organ positioning. A detailed understanding of how these factors work in combination will enable us to address outstanding questions in flower development including how distinct shapes and positions of floral organs are generated. Experimental approaches and computer-based modeling will be required to characterize gene-regulatory networks at the level of single cells.
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Affiliation(s)
- Marcus G Heisler
- School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia
| | - Henrik Jönsson
- Sainsbury Laboratory, University of Cambridge, UK; Department of Applied Mathematics and Theoretical Physics, University of Cambridge, UK; Computational Biology and Biological Physics, Lund University, Sweden
| | - Stephan Wenkel
- Department of Plant & Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Kerstin Kaufmann
- Humboldt-Universität zu Berlin, Institute of Biology, Philippstr. 13, 10115, Berlin, Germany.
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22
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DeGennaro D, Urquidi Camacho RA, Zhang L, Shpak ED. Initiation of aboveground organ primordia depends on combined action of auxin, ERECTA family genes, and PINOID. PLANT PHYSIOLOGY 2022; 190:794-812. [PMID: 35703946 PMCID: PMC9434323 DOI: 10.1093/plphys/kiac288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Leaves and flowers are produced by the shoot apical meristem (SAM) at a certain distance from its center, a process that requires the hormone auxin. The amount of auxin and the pattern of its distribution in the initiation zone determine the size and spatial arrangement of organ primordia. Auxin gradients in the SAM are formed by PIN-FORMED (PIN) auxin efflux carriers whose polar localization in the plasma membrane depends on the protein kinase PINOID (PID). Previous work determined that ERECTA (ER) family genes (ERfs) control initiation of leaves. ERfs are plasma membrane receptors that enable cell-to-cell communication by sensing extracellular small proteins from the EPIDERMAL PATTERNING FACTOR/EPF-LIKE (EPF/EPFL) family. Here, we investigated whether ERfs regulate initiation of organs by altering auxin distribution or signaling in Arabidopsis (Arabidopsis thaliana). Genetic and pharmacological data suggested that ERfs do not regulate organogenesis through PINs while transcriptomics data showed that ERfs do not alter primary transcriptional responses to auxin. Our results indicated that in the absence of ERf signaling the peripheral zone cells inefficiently initiate leaves in response to auxin signals and that increased accumulation of auxin in the er erecta-like1 (erl1) erl2 SAM can partially rescue organ initiation defects. We propose that both auxin and ERfs are essential for leaf initiation and that they have common downstream targets. Genetic data also indicated that the role of PID in initiation of cotyledons and leaves cannot be attributed solely to regulation of PIN polarity and PID is likely to have other functions in addition to regulation of auxin distribution.
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Affiliation(s)
- Daniel DeGennaro
- Department of Biochemistry, Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee 37996, USA
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23
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Yang S, de Haan M, Mayer J, Janacek DP, Hammes UZ, Poppenberger B, Sieberer T. A novel chemical inhibitor of polar auxin transport promotes shoot regeneration by local enhancement of HD-ZIP III transcription. THE NEW PHYTOLOGIST 2022; 235:1111-1128. [PMID: 35491431 DOI: 10.1111/nph.18196] [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: 11/18/2021] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
De novo shoot organogenesis is a prerequisite for numerous applications in plant research and breeding but is often a limiting factor, for example, in genome editing approaches. Class III homeodomain-leucine zipper (HD-ZIP III) transcription factors have been characterized as crucial regulators of shoot specification, however up-stream components controlling their activity during shoot regeneration are only partially identified. In a chemical genetic screen, we isolated ZIC2, a novel activator of HD-ZIP III activity. Using molecular, physiological and hormone transport analyses in Arabidopsis and sunflower (Helianthus annuus), we examined the molecular mechanism by which the drug promotes HD-ZIP III expression. ZIC2-dependent upregulation of HD-ZIP III transcription promotes shoot regeneration in Arabidopsis and is accompanied by the induction of shoot specifying factors WUS and RAP2.6L and a subset of cytokinin biosynthesis enzymes. ZIC2's effect on HD-ZIP III expression and regeneration is based on its ability to limit polar auxin transport. We further provide evidence that chemical modulation of auxin efflux can enhance de novo shoot formation in the regeneration recalcitrant species sunflower. Activation of HD-ZIP III transcription during shoot regeneration depends on the local distribution of auxin and chemical modulation of auxin transport can be used to overcome poor shoot organogenesis in tissue culture.
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Affiliation(s)
- Saiqi Yang
- Research Unit Plant Growth Regulation, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Marjolein de Haan
- Research Unit Plant Growth Regulation, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Julius Mayer
- Research Unit Plant Growth Regulation, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Dorina P Janacek
- Plant Systems Biology, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Ulrich Z Hammes
- Plant Systems Biology, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Brigitte Poppenberger
- Biotechnology of Horticultural Crops, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
| | - Tobias Sieberer
- Research Unit Plant Growth Regulation, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
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24
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Transcriptional reprogramming during floral fate acquisition. iScience 2022; 25:104683. [PMID: 35856019 PMCID: PMC9287482 DOI: 10.1016/j.isci.2022.104683] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/13/2022] [Accepted: 06/23/2022] [Indexed: 11/20/2022] Open
Abstract
Coordinating growth and patterning is essential for eukaryote morphogenesis. In plants, auxin is a key regulator of morphogenesis implicated throughout development. Despite this central role, our understanding of how auxin coordinates cell fate and growth changes is still limited. Here, we addressed this question using a combination of genomic screens to delve into the transcriptional network induced by auxin at the earliest stage of flower development, prior to morphological changes. We identify a shoot-specific network suggesting that auxin initiates growth through an antagonistic regulation of growth-promoting and growth-repressive hormones, quasi-synchronously to floral fate specification. We further identify two DNA-binding One Zinc Finger (DOF) transcription factors acting in an auxin-dependent network that could interface growth and cell fate from the early stages of flower development onward. Pharmacological approach to probe transcriptional responses in shoot meristems Analysis of a shoot-specific network regulated by auxin during flower initiation Two DOF transcription factors are induced in flower primordia The DOF genes potentially link growth to organ identity acquisition
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25
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Sang Q, Vayssières A, Ó'Maoiléidigh DS, Yang X, Vincent C, Bertran Garcia de Olalla E, Cerise M, Franzen R, Coupland G. MicroRNA172 controls inflorescence meristem size through regulation of APETALA2 in Arabidopsis. THE NEW PHYTOLOGIST 2022; 235:356-371. [PMID: 35318684 DOI: 10.1111/nph.18111] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/07/2022] [Indexed: 05/22/2023]
Abstract
The APETALA2 (AP2) transcription factor regulates flower development, floral transition and shoot apical meristem (SAM) maintenance in Arabidopsis. AP2 is also regulated at the post-transcriptional level by microRNA172 (miR172), but the contribution of this to SAM maintenance is poorly understood. We generated transgenic plants carrying a form of AP2 that is resistant to miR172 (rAP2) or carrying a wild-type AP2 susceptible to miR172. Phenotypic and genetic analyses were performed on these lines and mir172 mutants to study the role of AP2 regulation by miR172 on meristem size and the rate of flower production. We found that rAP2 enlarges the inflorescence meristem by increasing cell size and cell number. Misexpression of rAP2 from heterologous promoters showed that AP2 acts in the central zone (CZ) and organizing center (OC) to increase SAM size. Furthermore, we found that AP2 is negatively regulated by AUXIN RESPONSE FACTOR 3 (ARF3). However, genetic analyses indicated that ARF3 also influences SAM size and flower production rate independently of AP2. The study identifies miR172/AP2 as a regulatory module controlling inflorescence meristem size and suggests that transcriptional regulation of AP2 by ARF3 fine-tunes SAM size determination.
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Affiliation(s)
- Qing Sang
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Alice Vayssières
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Diarmuid S Ó'Maoiléidigh
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
- Institute of Systems, Integrative, and Molecular Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Xia Yang
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Coral Vincent
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | | | - Martina Cerise
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Rainer Franzen
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - George Coupland
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
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26
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Vijayan A, Strauss S, Tofanelli R, Mody TA, Lee K, Tsiantis M, Smith RS, Schneitz K. The annotation and analysis of complex 3D plant organs using 3DCoordX. PLANT PHYSIOLOGY 2022; 189:1278-1295. [PMID: 35348744 PMCID: PMC9237718 DOI: 10.1093/plphys/kiac145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
A fundamental question in biology concerns how molecular and cellular processes become integrated during morphogenesis. In plants, characterization of 3D digital representations of organs at single-cell resolution represents a promising approach to addressing this problem. A major challenge is to provide organ-centric spatial context to cells of an organ. We developed several general rules for the annotation of cell position and embodied them in 3DCoordX, a user-interactive computer toolbox implemented in the open-source software MorphoGraphX. 3DCoordX enables rapid spatial annotation of cells even in highly curved biological shapes. Using 3DCoordX, we analyzed cellular growth patterns in organs of several species. For example, the data indicated the presence of a basal cell proliferation zone in the ovule primordium of Arabidopsis (Arabidopsis thaliana). Proof-of-concept analyses suggested a preferential increase in cell length associated with neck elongation in the archegonium of Marchantia (Marchantia polymorpha) and variations in cell volume linked to central morphogenetic features of a trap of the carnivorous plant Utricularia (Utricularia gibba). Our work demonstrates the broad applicability of the developed strategies as they provide organ-centric spatial context to cellular features in plant organs of diverse shape complexity.
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Affiliation(s)
| | | | - Rachele Tofanelli
- Plant Developmental Biology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Tejasvinee Atul Mody
- Plant Developmental Biology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | | | - Miltos Tsiantis
- Department of Comparative Developmental and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Richard S Smith
- Department of Comparative Developmental and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- The John Innes Centre, Norwich, UK
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Zhao X, Yang J, Li X, Li G, Sun Z, Chen Y, Chen Y, Xia M, Li Y, Yao L, Hou H. Identification and expression analysis of GARP superfamily genes in response to nitrogen and phosphorus stress in Spirodela polyrhiza. BMC PLANT BIOLOGY 2022; 22:308. [PMID: 35751022 PMCID: PMC9233324 DOI: 10.1186/s12870-022-03696-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/13/2022] [Indexed: 06/12/2023]
Abstract
BACKGROUND GARP transcription factors perform critical roles in plant development and response to environmental stimulus, especially in the phosphorus (P) and nitrogen (N) sensing and uptake. Spirodela polyrhiza (giant duckweed) is widely used for phytoremediation and biomass production due to its rapid growth and efficient N and P removal capacities. However, there has not yet been a comprehensive analysis of the GRAP gene family in S. polyrhiza. RESULTS We conducted a comprehensive study of GRAP superfamily genes in S. polyrhiza. First, we investigated 35 SpGARP genes which have been classified into three groups based on their gene structures, conserved motifs, and phylogenetic relationship. Then, we identified the duplication events, performed the synteny analysis, and calculated the Ka/Ks ratio in these SpGARP genes. The regulatory and co-expression networks of SpGARPs were further constructed using cis-acting element analysis and weighted correlation network analysis (WGCNA). Finally, the expression pattern of SpGARP genes were analyzed using RNA-seq data and qRT-PCR, and several NIGT1 transcription factors were found to be involved in both N and P starvation responses. CONCLUSIONS The study provides insight into the evolution and function of GARP superfamily in S. polyrhiza, and lays the foundation for the further functional verification of SpGARP genes.
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Affiliation(s)
- Xuyao Zhao
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Jingjing Yang
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Xiaozhe Li
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Gaojie Li
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Zuoliang Sun
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yan Chen
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yimeng Chen
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Manli Xia
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yixian Li
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lunguang Yao
- Henan Key Laboratory of Ecological Security for Water Source Region of Mid-Line of South-to-North Diversion Project of Henan Province, Collaborative Innovation Center of Water Security for Water Source Region of Mid-Line of South-to-North Diversion Project of Henan Province, Nanyang Normal University, Nanyang, 473061, China
| | - Hongwei Hou
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
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28
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Guan C, Qiao L, Xiong Y, Zhang L, Jiao Y. Coactivation of antagonistic genes stabilizes polarity patterning during shoot organogenesis. SCIENCE ADVANCES 2022; 8:eabn0368. [PMID: 35675392 PMCID: PMC9176745 DOI: 10.1126/sciadv.abn0368] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
Spatiotemporal patterns of gene expression are instrumental to morphogenesis. A stable pattern interface, often between reciprocal-inhibiting morphogens, must be robustly maintained after initial patterning cues diminish, organ growth, or organ geometry changes. In plants, floral and leaf primordia obtain the adaxial-abaxial pattern at the shoot apical meristem periphery. However, it is unknown how the pattern is maintained after primordia have left the shoot apex. Here, through a combination of computational simulations, time-lapse imaging, and genetic analysis, we propose a model in which auxin simultaneously promotes both adaxial and abaxial domains of expression. Furthermore, we identified multilevel feedback regulation of auxin signaling to refine the spatiotemporal patterns. Our results demonstrate that coactivation by auxin determines and stabilizes antagonistic adaxial-abaxial patterning during aerial organ formation.
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Affiliation(s)
- Chunmei Guan
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Lingxia Qiao
- Beijing International Center for Mathematical Research, Center for Quantitative Biology, Peking University, Beijing 100871, China
| | - Yuanyuan Xiong
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Lei Zhang
- Beijing International Center for Mathematical Research, Center for Quantitative Biology, Peking University, Beijing 100871, China
| | - Yuling Jiao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Center for Quantitative Biology, Peking University, Beijing 100871, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
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Briginshaw LN, Flores‐Sandoval E, Dierschke T, Alvarez JP, Bowman JL. KANADI promotes thallus differentiation and FR-induced gametangiophore formation in the liverwort Marchantia. THE NEW PHYTOLOGIST 2022; 234:1377-1393. [PMID: 35181887 PMCID: PMC9311212 DOI: 10.1111/nph.18046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/07/2022] [Indexed: 05/26/2023]
Abstract
In angiosperms, KANADI transcription factors have roles in the sporophyte generation regulating tissue polarity, organogenesis and shade avoidance responses, but are not required during the gametophyte generation. Whether these roles are conserved in the gametophyte-dominant bryophyte lineages is unknown, which we examined by characterising the sole KANADI ortholog, MpKAN, in the liverwort Marchantia polymorpha. In contrast to angiosperm orthologs, MpKAN functions in the gametophyte generation in Marchantia, where it regulates apical branching and tissue differentiation, but does not influence tissue polarity in either generation. MpKAN can partially rescue the sporophyte polarity defects of kanadi mutants in Arabidopsis, indicating that MpKAN has conserved biochemical activity to its angiosperm counterparts. Mpkan loss-of-function plants display defects in far-red (FR) light responses. Mpkan plants have reduced FR-induced growth tropisms, have a delayed transition to sexual reproduction and fail to correctly form gametangiophores. Our results indicate that MpKAN is a modulator of FR responses, which may reflect a conserved role for KANADI across land plants. Under FR, MpKAN negatively regulates MpDELLA expression, suggesting that MpKAN and MpDELLA act in a pathway regulating FR responses, placing MpKAN in a gene regulatory network exhibiting similarities with those of angiosperms.
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Affiliation(s)
- Liam N. Briginshaw
- School of Biological SciencesMonash UniversityWellington RdClayton, MelbourneVic.3800Australia
- ARC Centre of Excellence for Plant Success in Nature and AgricultureMonash UniversityWellington RdMelbourneVic.3800Australia
| | - Eduardo Flores‐Sandoval
- School of Biological SciencesMonash UniversityWellington RdClayton, MelbourneVic.3800Australia
- ARC Centre of Excellence for Plant Success in Nature and AgricultureMonash UniversityWellington RdMelbourneVic.3800Australia
| | - Tom Dierschke
- School of Biological SciencesMonash UniversityWellington RdClayton, MelbourneVic.3800Australia
| | - John P. Alvarez
- School of Biological SciencesMonash UniversityWellington RdClayton, MelbourneVic.3800Australia
- ARC Centre of Excellence for Plant Success in Nature and AgricultureMonash UniversityWellington RdMelbourneVic.3800Australia
| | - John L. Bowman
- School of Biological SciencesMonash UniversityWellington RdClayton, MelbourneVic.3800Australia
- ARC Centre of Excellence for Plant Success in Nature and AgricultureMonash UniversityWellington RdMelbourneVic.3800Australia
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30
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Schubert J, Li Y, Mendes MA, Fei D, Dickinson H, Moore I, Baroux C. A procedure for Dex-induced gene transactivation in Arabidopsis ovules. PLANT METHODS 2022; 18:41. [PMID: 35351175 PMCID: PMC8962214 DOI: 10.1186/s13007-022-00879-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Elucidating the genetic and molecular control of plant reproduction often requires the deployment of functional approaches based on reverse or forward genetic screens. The loss-of-function of essential genes, however, may lead to plant lethality prior to reproductive development or to the formation of sterile structures before the organ-of-interest can be analyzed. In these cases, inducible approaches that enable a spatial and temporal control of the genetic perturbation are extremely valuable. Genetic induction in reproductive organs, such as the ovule, deeply embedded in the flower, is a delicate procedure that requires both optimization and validation. RESULTS Here we report on a streamlined procedure enabling reliable induction of gene expression in Arabidopsis ovule and anther tissues using the popular pOP/LhGR Dex-inducible system. We demonstrate its efficiency and reliability using fluorescent reporter proteins and histochemical detection of the GUS reporter gene. CONCLUSION The pOP/LhGR system allows for a rapid, efficient, and reliable induction of transgenes in developing ovules without compromising developmental progression. This approach opens new possibilities for the functional analysis of candidate regulators in sporogenesis and gametogenesis, which is otherwise affected by early lethality in conventional, stable mutants.
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Affiliation(s)
- Jasmin Schubert
- Institute of Plant and Microbial Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Yanru Li
- Institute of Plant and Microbial Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Marta A Mendes
- Dipartimento di Bioscienze, Universitá degli Studi di Milano, 20133, Milan, Italy
| | - Danli Fei
- Institute of Plant and Microbial Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Hugh Dickinson
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - Ian Moore
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - Célia Baroux
- Institute of Plant and Microbial Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
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31
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Burian A, Paszkiewicz G, Nguyen KT, Meda S, Raczyńska-Szajgin M, Timmermans MCP. Specification of leaf dorsiventrality via a prepatterned binary readout of a uniform auxin input. NATURE PLANTS 2022; 8:269-280. [PMID: 35318449 DOI: 10.1038/s41477-022-01111-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Developmental boundaries play an important role in coordinating the growth and patterning of lateral organs. In plants, specification of dorsiventrality is critical to leaf morphogenesis. Despite its central importance, the mechanism by which leaf primordia acquire adaxial versus abaxial cell fates to establish dorsiventrality remains a topic of much debate. Here, by combining time-lapse confocal imaging, cell lineage tracing and molecular genetic analyses, we demonstrate that a stable boundary between adaxial and abaxial cell fates is specified several plastochrons before primordium emergence when high auxin levels accumulate on a meristem prepattern formed by the AS2 and KAN1 transcription factors. This occurrence triggers a transient induction of ARF3 and an auxin transcriptional response in AS2-marked progenitors that distinguishes adaxial from abaxial identity. As the primordium emerges, dynamic shifts in auxin distribution and auxin-related gene expression gradually resolve this initial polarity into the stable regulatory network known to maintain adaxial-abaxial polarity within the developing organ. Our data show that spatial information from an AS2-KAN1 meristem prepattern governs the conversion of a uniform auxin input into an ARF-dependent binary auxin response output to specify adaxial-abaxial polarity. Auxin thus serves as a single morphogenic signal that orchestrates distinct, spatially separated responses to coordinate the positioning and emergence of a new organ with its patterning.
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Affiliation(s)
- Agata Burian
- Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Katowice, Poland
| | - Gael Paszkiewicz
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Khoa Thi Nguyen
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam
| | - Shreyas Meda
- Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany
| | - Magdalena Raczyńska-Szajgin
- Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Katowice, Poland
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32
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Linh NM, Scarpella E. Confocal Imaging of Developing Leaves. Curr Protoc 2022; 2:e349. [PMID: 35072973 DOI: 10.1002/cpz1.349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Questions in developmental biology are most frequently addressed by using fluorescent markers of otherwise invisible cell states. In plants, such questions can be addressed most conveniently in leaves. Indeed, from the formation of stomata and trichomes within the leaf epidermis to that of vein networks deep into the leaf inner tissue, leaf cells and tissues differentiate anew during the development of each leaf. Moreover, leaves are produced in abundance and are easily accessible to visualization and perturbation. Yet a detailed procedure for the perturbation, dissection, mounting, and imaging of developing leaves has not been described. Here we address this limitation (1) by providing robust, step-by-step protocols for the local application of the plant hormone auxin to developing leaves and for the routine dissection and mounting of leaves and leaf primordia, and (2) by offering practical guidelines for the optimization of imaging parameters for confocal microscopy. We describe the procedure for the first leaves of Arabidopsis, but the same approach can be easily applied to other leaves of Arabidopsis or to leaves of other plants. © 2022 Wiley Periodicals LLC. Support Protocol 1: Preparation of plant growth medium Support Protocol 2: Preparation of growth medium plates Basic Protocol 1: Seed sterilization, sowing, and germination, and seedling growth Support Protocol 3: Preparation of IAA-lanolin paste Basic Protocol 2: Application of IAA-lanolin paste to 3.5-DAG first leaves Basic Protocol 3: Dissection of 3- to 6-DAG first leaves and leaf primordia Basic Protocol 4: Dissection of 1- and 2-DAG first-leaf primordia Basic Protocol 5: Mounting of dissected leaves and leaf primordia Support Protocol 4: Quality check of mounted leaves and leaf primordia by fluorescence microscopy Basic Protocol 6: Imaging of mounted leaves and leaf primordia by confocal microscopy.
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Affiliation(s)
- Nguyen Manh Linh
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Enrico Scarpella
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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33
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Gonçalves B. Case not closed: the mystery of the origin of the carpel. EvoDevo 2021; 12:14. [PMID: 34911578 PMCID: PMC8672599 DOI: 10.1186/s13227-021-00184-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/05/2021] [Indexed: 11/25/2022] Open
Abstract
The carpel is a fascinating structure that plays a critical role in flowering plant reproduction and contributed greatly to the evolutionary success and diversification of flowering plants. The remarkable feature of the carpel is that it is a closed structure that envelopes the ovules and after fertilization develops into the fruit which protects, helps disperse, and supports seed development into a new plant. Nearly all plant-based foods are either derived from a flowering plant or are a direct product of the carpel. Given its importance it's no surprise that plant and evolutionary biologists have been trying to explain the origin of the carpel for a long time. Before carpel evolution seeds were produced on open leaf-like structures that are exposed to the environment. When the carpel evolved in the stem lineage of flowering plants, seeds became protected within its closed structure. The evolutionary transition from that open precursor to the closed carpel remains one of the greatest mysteries of plant evolution. In recent years, we have begun to complete a picture of what the first carpels might have looked like. On the other hand, there are still many gaps in our understanding of what the precursor of the carpel looked like and what changes to its developmental mechanisms allowed for this evolutionary transition. This review aims to present an overview of existing theories of carpel evolution with a particular emphasis on those that account for the structures that preceded the carpel and/or present testable developmental hypotheses. In the second part insights from the development and evolution of diverse plant organs are gathered to build a developmental hypothesis for the evolutionary transition from a hypothesized laminar open structure to the closed structure of the carpel.
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34
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Heisler MG. Integration of Core Mechanisms Underlying Plant Aerial Architecture. FRONTIERS IN PLANT SCIENCE 2021; 12:786338. [PMID: 34868186 PMCID: PMC8637408 DOI: 10.3389/fpls.2021.786338] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 10/27/2021] [Indexed: 06/03/2023]
Abstract
Over the last decade or so important progress has been made in identifying and understanding a set of patterning mechanisms that have the potential to explain many aspects of plant morphology. These include the feedback loop between mechanical stresses and interphase microtubules, the regulation of plant cell polarity and the role of adaxial and abaxial cell type boundaries. What is perhaps most intriguing is how these mechanisms integrate in a combinatorial manner that provides a means to generate a large variety of commonly seen plant morphologies. Here, I review our current understanding of these mechanisms and discuss the links between them.
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Affiliation(s)
- Marcus G. Heisler
- School of Life and Environmental Science, University of Sydney, Camperdown, NSW, Australia
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35
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Mizuta Y. Advances in Two-Photon Imaging in Plants. PLANT & CELL PHYSIOLOGY 2021; 62:1224-1230. [PMID: 34019083 PMCID: PMC8579158 DOI: 10.1093/pcp/pcab062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/16/2021] [Accepted: 05/20/2021] [Indexed: 05/06/2023]
Abstract
Live and deep imaging play a significant role in the physiological and biological study of organisms. Two-photon excitation microscopy (2PEM), also known as multiphoton excitation microscopy, is a fluorescent imaging technique that allows deep imaging of living tissues. Two-photon lasers use near-infrared (NIR) pulse lasers that are less invasive and permit deep tissue penetration. In this review, recent advances in two-photon imaging and their applications in plant studies are discussed. Compared to confocal microscopy, NIR 2PEM exhibits reduced plant-specific autofluorescence, thereby achieving greater depth and high-resolution imaging in plant tissues. Fluorescent proteins with long emission wavelengths, such as orange-red fluorescent proteins, are particularly suitable for two-photon live imaging in plants. Furthermore, deep- and high-resolution imaging was achieved using plant-specific clearing methods. In addition to imaging, optical cell manipulations can be performed using femtosecond pulsed lasers at the single cell or organelle level. Optical surgery and manipulation can reveal cellular communication during development. Advances in in vivo imaging using 2PEM will greatly benefit biological studies in plant sciences.
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Affiliation(s)
- Yoko Mizuta
- Institute for Advanced Research (IAR), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
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36
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Ma Y, Wolf S, Lohmann JU. Casting the Net-Connecting Auxin Signaling to the Plant Genome. Cold Spring Harb Perspect Biol 2021; 13:a040006. [PMID: 33903151 PMCID: PMC8559546 DOI: 10.1101/cshperspect.a040006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Auxin represents one of the most potent and most versatile hormonal signals in the plant kingdom. Built on a simple core of only a few dedicated components, the auxin signaling system plays important roles for diverse aspects of plant development, physiology, and defense. Key to the diversity of context-dependent functional outputs generated by cells in response to this small molecule are gene duplication events and sub-functionalization of signaling components on the one hand, and a deep embedding of the auxin signaling system into complex regulatory networks on the other hand. Together, these evolutionary innovations provide the mechanisms to allow each cell to display a highly specific auxin response that suits its individual requirements. In this review, we discuss the regulatory networks connecting auxin with a large number of diverse pathways at all relevant levels of the signaling system ranging from biosynthesis to transcriptional response.
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Affiliation(s)
- Yanfei Ma
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, D-69120 Heidelberg, Germany
| | - Sebastian Wolf
- Cell Wall Signalling Group, Centre for Organismal Studies, Heidelberg University, D-69120 Heidelberg, Germany
| | - Jan U Lohmann
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, D-69120 Heidelberg, Germany
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37
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Post-Embryonic Lateral Organ Development and Adaxial-Abaxial Polarity Are Regulated by the Combined Effect of ENHANCER OF SHOOT REGENERATION 1 and WUSCHEL in Arabidopsis Shoots. Int J Mol Sci 2021; 22:ijms221910621. [PMID: 34638958 PMCID: PMC8508843 DOI: 10.3390/ijms221910621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/19/2021] [Accepted: 09/28/2021] [Indexed: 11/17/2022] Open
Abstract
The development of above-ground lateral organs is initiated at the peripheral zone of the shoot apical meristem (SAM). The coordination of cell fate determination and the maintenance of stem cells are achieved through a complex regulatory network comprised of transcription factors. Two AP2/ERF transcription factor family genes, ESR1/DRN and ESR2/DRNL/SOB/BOL, regulate cotyledon and flower formation and de novo organogenesis in tissue culture. However, their roles in post-embryonic lateral organ development remain elusive. In this study, we analyzed the genetic interactions among SAM-related genes, WUS and STM, two ESR genes, and one of the HD-ZIP III members, REV, whose protein product interacts with ESR1 in planta. We found that esr1 mutations substantially enhanced the wus and stm phenotypes, which bear a striking resemblance to those of the wus rev and stm rev double mutants, respectively. Aberrant adaxial–abaxial polarity is observed in wus esr1 at relatively low penetrance. On the contrary, the esr2 mutation partially suppressed stm phenotypes in the later vegetative phase. Such complex genetic interactions appear to be attributed to the distinct expression pattern of two ESR genes because the ESR1 promoter-driving ESR2 is capable of rescuing phenotypes caused by the esr1 mutation. Our results pose the unique genetic relevance of ESR1 and the SAM-related gene interactions in the development of rosette leaves.
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Gene duplication at the Fascicled ear1 locus controls the fate of inflorescence meristem cells in maize. Proc Natl Acad Sci U S A 2021; 118:2019218118. [PMID: 33579824 PMCID: PMC7896288 DOI: 10.1073/pnas.2019218118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The maize ear is unbranched and terminates in a single point. The ear and tassel inflorescences of Fascicled ear mutants fail to grow as a single point and instead are branched. This phenotype results from the misexpression of duplicated transcription factors, ZMM8 and DRL2. We hypothesize that these gene rearrangements create regulatory sequences that cause misexpression in early inflorescence meristems, thus activating a laminar program, ablating the meristem, and producing branches. This work demonstrates that zmm8 and drl2 must be restricted from the inflorescence meristem to maintain its terminal point, and conversely, a mechanism by which branching may be imposed. Manipulation of these genes can be used to alter plant architecture, potentially to improve agronomic traits. Plant meristems are self-renewing groups of pluripotent stem cells that produce lateral organs in a stereotypical pattern. Of interest is how the radially symmetrical meristem produces laminar lateral organs. Both the male and female inflorescence meristems of the dominant Fascicled ear (Fas1) mutant fail to grow as a single point and instead show deep branching. Positional cloning of two independent Fas1 alleles identified an ∼160 kb region containing two floral genes, the MADS-box gene, zmm8, and the YABBY gene, drooping leaf2 (drl2). Both genes are duplicated within the Fas1 locus and spatiotemporally misexpressed in the mutant inflorescence meristems. Increased zmm8 expression alone does not affect inflorescence development; however, combined misexpression of zmm8, drl2, and their syntenic paralogs zmm14 and drl1, perturbs meristem organization. We hypothesize that misexpression of the floral genes in the inflorescence and their potential interaction cause ectopic activation of a laminar program, thereby disrupting signaling necessary for maintenance of radially symmetrical inflorescence meristems. Consistent with this hypothesis, RNA sequencing and in situ analysis reveal altered expression patterns of genes that define distinct zones of the meristem and developing leaf. Our findings highlight the importance of strict spatiotemporal patterns of expression for both zmm8 and drl2 and provide an example of phenotypes arising from tandem gene duplications.
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Wang H, Kong F, Zhou C. From genes to networks: The genetic control of leaf development. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:1181-1196. [PMID: 33615731 DOI: 10.1111/jipb.13084] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/16/2021] [Indexed: 05/15/2023]
Abstract
Substantial diversity exists for both the size and shape of the leaf, the main photosynthetic organ of flowering plants. The two major forms of leaf are simple leaves, in which the leaf blade is undivided, and compound leaves, which comprise several leaflets. Leaves form at the shoot apical meristem from a group of undifferentiated cells, which first establish polarity, then grow and differentiate. Each of these processes is controlled by a combination of transcriptional regulators, microRNAs and phytohormones. The present review documents recent advances in our understanding of how these various factors modulate the development of both simple leaves (focusing mainly on the model plant Arabidopsis thaliana) and compound leaves (focusing mainly on the model legume species Medicago truncatula).
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Affiliation(s)
- Hongfeng Wang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266101, China
- Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou, 510006, China
| | - Fanjiang Kong
- Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou, 510006, China
| | - Chuanen Zhou
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266101, China
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Bhatia N, Runions A, Tsiantis M. Leaf Shape Diversity: From Genetic Modules to Computational Models. ANNUAL REVIEW OF PLANT BIOLOGY 2021; 72:325-356. [PMID: 34143649 DOI: 10.1146/annurev-arplant-080720-101613] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Plant leaves display considerable variation in shape. Here, we introduce key aspects of leaf development, focusing on the morphogenetic basis of leaf shape diversity. We discuss the importance of the genetic control of the amount, duration, and direction of cellular growth for the emergence of leaf form. We highlight how the combined use of live imaging and computational frameworks can help conceptualize how regulated cellular growth is translated into different leaf shapes. In particular, we focus on the morphogenetic differences between simple and complex leaves and how carnivorous plants form three-dimensional insect traps. We discuss how evolution has shaped leaf diversity in the case of complex leaves, by tinkering with organ-wide growth and local growth repression, and in carnivorous plants, by modifying the relative growth of the lower and upper sides of the leaf primordium to create insect-digesting traps.
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Affiliation(s)
- Neha Bhatia
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany;
| | - Adam Runions
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany;
- Current affiliation: Department of Computer Science, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Miltos Tsiantis
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany;
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41
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Zhao F, Traas J. Stable establishment of organ polarity occurs several plastochrons before primordium outgrowth in Arabidopsis. Development 2021; 148:269138. [PMID: 34132346 PMCID: PMC8255034 DOI: 10.1242/dev.198820] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 05/06/2021] [Indexed: 11/21/2022]
Abstract
In many species, leaves are initiated at the flanks of shoot meristems. Subsequent growth usually occurs mainly in the plane of the leaf blade, which leads to the formation of a bifacial leaf with dorsoventral identities. In a classical set of surgical experiments in potato meristems, Sussex provided evidence that dorsoventrality depends on a signal emanating from the meristem center. Although these results could be reproduced in tomato, this concept has been debated. We revisited these experiments in Arabidopsis, in which a range of markers are available to target the precise site of ablation. Using specific markers for organ founder cells and dorsoventral identity, we were unable to perturb the polarity of leaves and sepals long before organ outgrowth. Although results in Solanaceae suggested that dorsoventral patterning was unstable during early development, we found that, in Arabidopsis, the local information contained within and around the primordium is able to withstand major invasive perturbations, long before polarity is fully established. Summary: We revisited classical surgical experiments in Solanaceae, using precise laser ablations to show that dorsoventral patterning in vegetative and floral meristems in Arabidopsis is robustly programmed in primordia some time before polarity is completely established.
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Affiliation(s)
- Feng Zhao
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon 1, ENS-Lyon, INRAE, CNRS, UCBL, 46 Allée d'Italie, 69364 Lyon, France
| | - Jan Traas
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon 1, ENS-Lyon, INRAE, CNRS, UCBL, 46 Allée d'Italie, 69364 Lyon, France
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Nukazuka A, Yamaguchi T, Tsukaya H. A Role for Auxin in Triggering Lamina Outgrowth of Unifacial Leaves. PLANT PHYSIOLOGY 2021; 186:1013-1024. [PMID: 33620494 PMCID: PMC8195525 DOI: 10.1093/plphys/kiab087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 01/31/2021] [Indexed: 05/26/2023]
Abstract
A common morphological feature of typical angiosperms is the patterning of lateral organs along primary axes of asymmetry-a proximodistal, a mediolateral, and an adaxial-abaxial axis. Angiosperm leaves usually have distinct adaxial-abaxial identity, which is required for the development of a flat shape. By contrast, many unifacial leaves, consisting of only the abaxial side, show a flattened morphology. This implicates a unique mechanism that allows leaf flattening independent of adaxial-abaxial identity. In this study, we report a role for auxin in outgrowth of unifacial leaves. In two closely related unifacial-leaved species of Juncaceae, Juncus prismatocarpus with flattened leaves, and Juncus wallichianus with transversally radialized leaves, the auxin-responsive gene GLYCOSIDE HYDROLASE3 displayed spatially different expression patterns within leaf primordia. Treatment of J. prismatocarpus seedlings with exogenous auxin or auxin transport inhibitors, which disturb endogenous auxin distribution, eliminated leaf flatness, resulting in a transversally radialized morphology. These treatments did not affect the radialized morphology of leaves of J. wallichianus. Moreover, elimination of leaf flatness by these treatments accompanied dysregulated expression of genetic factors needed to specify the leaf central-marginal polarity in J. prismatocarpus. The findings imply that lamina outgrowth of unifacial leaves relies on proper placement of auxin, which might induce initial leaf flattening and subsequently act to specify leaf polarity, promoting further flattening growth of leaves.
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Affiliation(s)
- Akira Nukazuka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Takahiro Yamaguchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Hirokazu Tsukaya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
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Vernoux T, Besnard F, Godin C. What shoots can teach about theories of plant form. NATURE PLANTS 2021; 7:716-724. [PMID: 34099903 DOI: 10.1038/s41477-021-00930-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
Plants generate a large variety of shoot forms with regular geometries. These forms emerge primarily from the activity of a stem cell niche at the shoot tip. Recent efforts have established a theoretical framework of form emergence at the shoot tip, which has empowered the use of modelling in conjunction with biological approaches to begin to disentangle the biochemical and physical mechanisms controlling form development at the shoot tip. Here, we discuss how these advances get us closer to identifying the construction principles of plant shoot tips. Considering the current limits of our knowledge, we propose a roadmap for developing a general theory of form development at the shoot tip.
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Affiliation(s)
- Teva Vernoux
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon, France.
| | - Fabrice Besnard
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon, France
| | - Christophe Godin
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon, France
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Zhang T, Wang F, Elomaa P. Repatterning of the inflorescence meristem in Gerbera hybrida after wounding. JOURNAL OF PLANT RESEARCH 2021; 134:431-440. [PMID: 33543368 PMCID: PMC8106577 DOI: 10.1007/s10265-021-01253-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 01/03/2021] [Indexed: 06/12/2023]
Abstract
The Asteraceae plant family is characterized by inflorescences, called flower heads or capitula that may combine hundreds of individual florets into a single flower-like structure. The florets are arranged in a regular phyllotactic pattern with Fibonacci numbers of left- and right-winding spirals. Such a pattern may be disrupted due to physical constraints or by wounding occurring during the early meristem development. Recovery from wounding re-establishes patterning although the mechanisms have remained elusive. In this study, we applied Gerbera hybrida as a model system and established methods to conduct wounding experiments either with syringe needles or using laser ablation combined with live imaging of head meristems. By revisiting the historical experiments in sunflower, we conducted wounding to transgenic auxin reporter lines of gerbera and followed the recovery of cellular growth and meristem patterning. We show that wounding disrupted the expression of the gerbera CLAVATA3 (GhCLV3) gene that marks the undifferentiated meristematic region and led to de novo re-initiation of patterning at the wound margin. During the recovery growth, three to five layers of elongated cells showing periclinal cell division planes and lacking auxin signal were formed at the wound rim. DR5 auxin signal was shown to localize and form regularly spaced maxima in a distance from the wound rim. Consequently, spiral pattern of contact parastichies was re-established by stacking of new auxin maxima on top of the previous ones. The developed methods facilitate future studies on understanding the molecular mechanisms of de novo patterning of meristems.
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Affiliation(s)
- Teng Zhang
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, P.O.Box 27, 00014 Helsinki, Finland
| | - Feng Wang
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, P.O.Box 27, 00014 Helsinki, Finland
| | - Paula Elomaa
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, P.O.Box 27, 00014 Helsinki, Finland
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Romanova MA, Maksimova AI, Pawlowski K, Voitsekhovskaja OV. YABBY Genes in the Development and Evolution of Land Plants. Int J Mol Sci 2021; 22:4139. [PMID: 33923657 PMCID: PMC8074164 DOI: 10.3390/ijms22084139] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 12/27/2022] Open
Abstract
Mounting evidence from genomic and transcriptomic studies suggests that most genetic networks regulating the morphogenesis of land plant sporophytes were co-opted and modified from those already present in streptophyte algae and gametophytes of bryophytes sensu lato. However, thus far, no candidate genes have been identified that could be responsible for "planation", a conversion from a three-dimensional to a two-dimensional growth pattern. According to the telome theory, "planation" was required for the genesis of the leaf blade in the course of leaf evolution. The key transcription factors responsible for leaf blade development in angiosperms are YABBY proteins, which until recently were thought to be unique for seed plants. Yet, identification of a YABBY homologue in a green alga and the recent findings of YABBY homologues in lycophytes and hornworts suggest that YABBY proteins were already present in the last common ancestor of land plants. Thus, these transcriptional factors could have been involved in "planation", which fosters our understanding of the origin of leaves. Here, we summarise the current data on functions of YABBY proteins in the vegetative and reproductive development of diverse angiosperms and gymnosperms as well as in the development of lycophytes. Furthermore, we discuss a putative role of YABBY proteins in the genesis of multicellular shoot apical meristems and in the evolution of leaves in early divergent terrestrial plants.
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Affiliation(s)
- Marina A. Romanova
- Department of Botany, St. Petersburg State University, Universitetskaya Nab. 7/9, 190034 Saint Petersburg, Russia
| | - Anastasiia I. Maksimova
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376 Saint Petersburg, Russia;
| | - Katharina Pawlowski
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden;
| | - Olga V. Voitsekhovskaja
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376 Saint Petersburg, Russia;
- Saint Petersburg Electrotechnical University “LETI”, ul. Professora Popova 5, 197022 Saint Petersburg, Russia
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46
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Tomescu AMF. The stele - a developmental perspective on the diversity and evolution of primary vascular architecture. Biol Rev Camb Philos Soc 2021; 96:1263-1283. [PMID: 33655608 DOI: 10.1111/brv.12699] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 12/15/2022]
Abstract
The stele concept is one of the oldest enduring concepts in plant biology. Here, I review the history of the concept and build an argument for an updated view of steles and their evolution. Studies of stelar organization have generated a widely ranging array of definitions that determine the way we classify steles and construct scenarios about the evolution of stelar architecture. Because at the organismal level biological evolution proceeds by changes in development, concepts of structure need to be grounded in development to be relevant in an evolutionary perspective. For the stele, most traditional definitions that incorporate development have viewed it as the totality of tissues that either originate from procambium - currently the prevailing view - or are bordered by a boundary layer (e.g. endodermis). Consensus between these two perspectives can be reached by recasting the stele as a structural entity of dual nature. Following a brief review of the history of the stele concept, basic terminology related to stelar organization, and traditional classifications of the steles, I revisit boundary layers from the perspective of histogenesis as a dynamic mosaic of developmental domains. I review anatomical and molecular data to explore and reaffirm the importance of boundary layers for stelar organization. Drawing on information from comparative anatomy, developmental regulation, and the fossil record, I propose a stele concept that integrates both the boundary layer and the procambial perspectives, consistent with a dual nature of the stele. This dual stele model posits that stelar architecture is determined at the apical meristem by two major cell fate specification events: a first one that specifies a provascular domain and its boundaries, and a second event that specifies a procambial domain (which will mature into conducting tissues) from cell subpopulations of the provascular domain. If the position and extent of the developmental domains defined by the two events are determined by different concentrations of the same morphogen (most likely auxin), then the distribution of this organizer factor in the shoot apical meristem, as modulated by changes in axis size and the effect of lateral organs, can explain the different stelar configurations documented among tracheophytes. This model provides working hypotheses that incorporate assumptions and generate implications that can be tested empirically. The model also offers criteria for an updated classification of steles in line with current understanding of plant development. In this classification, steles fall into two major categories determined by the configuration of boundary layers: boundary protosteles and boundary siphonosteles, each with subtypes defined by the architecture of the vascular tissues. Validation of the dual stele model and, more generally, in-depth understanding of the regulation of stelar architecture, will necessitate targeted efforts in two areas: (i) the regulation of procambium, vascular tissue, and boundary layer specification in all extant vascular plants, considering that most of the diversity in stelar architecture is hosted by seed-free plants, which are the least explored in terms of developmental regulation; (ii) the configuration of vascular tissues and, especially, boundary layers, in as many extinct lineages as possible.
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Affiliation(s)
- Alexandru M F Tomescu
- Department of Biological Sciences, Humboldt State University, Arcata, CA, 95521, U.S.A
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47
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Cucinotta M, Cavalleri A, Chandler JW, Colombo L. Auxin and Flower Development: A Blossoming Field. Cold Spring Harb Perspect Biol 2021; 13:a039974. [PMID: 33355218 PMCID: PMC7849340 DOI: 10.1101/cshperspect.a039974] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The establishment of the species-specific floral organ body plan involves many coordinated spatiotemporal processes, which include the perception of positional information that specifies floral meristem and floral organ founder cells, coordinated organ outgrowth coupled with the generation and maintenance of inter-organ and inter-whorl boundaries, and the termination of meristem activity. Auxin is integrated within the gene regulatory networks that control these processes and plays instructive roles at the level of tissue-specific biosynthesis and polar transport to generate local maxima, perception, and signaling. Key features of auxin function in several floral contexts include cell nonautonomy, interaction with cytokinin gradients, and the central role of MONOPTEROS and ETTIN to regulate canonical and noncanonical auxin response pathways, respectively. Arabidopsis flowers are not representative of the enormous angiosperm floral diversity; therefore, comparative studies are required to understand how auxin underlies these developmental differences. It will be of great interest to compare the conservation of auxin pathways among flowering plants and to discuss the evolutionary role of auxin in floral development.
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Affiliation(s)
- Mara Cucinotta
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy
| | - Alex Cavalleri
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy
| | | | - Lucia Colombo
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy
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Xu X, Crow M, Rice BR, Li F, Harris B, Liu L, Demesa-Arevalo E, Lu Z, Wang L, Fox N, Wang X, Drenkow J, Luo A, Char SN, Yang B, Sylvester AW, Gingeras TR, Schmitz RJ, Ware D, Lipka AE, Gillis J, Jackson D. Single-cell RNA sequencing of developing maize ears facilitates functional analysis and trait candidate gene discovery. Dev Cell 2021; 56:557-568.e6. [PMID: 33400914 DOI: 10.1016/j.devcel.2020.12.015] [Citation(s) in RCA: 114] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/31/2020] [Accepted: 12/15/2020] [Indexed: 12/30/2022]
Abstract
Crop productivity depends on activity of meristems that produce optimized plant architectures, including that of the maize ear. A comprehensive understanding of development requires insight into the full diversity of cell types and developmental domains and the gene networks required to specify them. Until now, these were identified primarily by morphology and insights from classical genetics, which are limited by genetic redundancy and pleiotropy. Here, we investigated the transcriptional profiles of 12,525 single cells from developing maize ears. The resulting developmental atlas provides a single-cell RNA sequencing (scRNA-seq) map of an inflorescence. We validated our results by mRNA in situ hybridization and by fluorescence-activated cell sorting (FACS) RNA-seq, and we show how these data may facilitate genetic studies by predicting genetic redundancy, integrating transcriptional networks, and identifying candidate genes associated with crop yield traits.
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Affiliation(s)
- Xiaosa Xu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Megan Crow
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Brian R Rice
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Forrest Li
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Benjamin Harris
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Lei Liu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - Zefu Lu
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Liya Wang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Nathan Fox
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Xiaofei Wang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Jorg Drenkow
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Anding Luo
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA
| | - Si Nian Char
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Bing Yang
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
| | - Anne W Sylvester
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA
| | | | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Doreen Ware
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; USDA-ARS, Robert W. Holley Center, Ithaca, NY 14853, USA
| | - Alexander E Lipka
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jesse Gillis
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - David Jackson
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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Tang H, Bi H, Liu B, Lou S, Song Y, Tong S, Chen N, Jiang Y, Liu J, Liu H. WRKY33 interacts with WRKY12 protein to up-regulate RAP2.2 during submergence induced hypoxia response in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2021; 229:106-125. [PMID: 33098101 DOI: 10.1111/nph.17020] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/12/2020] [Indexed: 05/23/2023]
Abstract
Tolerance of hypoxia is essential for most plants, but the underlying mechanisms are largely unknown. Here we show that adaptation to submergence induced hypoxia in Arabidopsis involves up-regulation of RAP2.2 through interactive action of WRKY33 and WRKY12. WRKY33- or WRKY12-overexpressing plants showed enhanced resistance to hypoxia. Y2H, BiFC, Co-IP and pull-down experiments confirmed the interaction of WRKY33 with WRKY12. Genetic experiments showed that RAP2.2 acts downstream of WRKY33/WRKY12. WRKY33 and WRKY12 can bind to and activate RAP2.2 individually. Genetic and molecular experiments demonstrate that the two WRKYs can synergistically enhance activation towards RAP2.2 to increase hypoxia tolerance. WRKY33 expression is increased in RAP2.2-overexpressing plants, indicating a feedback regulation by RAP2.2 during submergence process, which was corroborated by EMSA, ChIP, dual-LUC and genetic experiments. Our results show that a regulatory cascade module involving WRKY33, WRKY12 and RAP2.2 plays a key role in submergence induced hypoxia response of Arabidopsis and illuminate functions of WRKYs in hypoxia tolerance.
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Affiliation(s)
- Hu Tang
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Hao Bi
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Bao Liu
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Shangling Lou
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Yan Song
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Shaofei Tong
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Ningning Chen
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Yuanzhong Jiang
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Jianquan Liu
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
| | - Huanhuan Liu
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, 610065, China
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50
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A WOX/Auxin Biosynthesis Module Controls Growth to Shape Leaf Form. Curr Biol 2020; 30:4857-4868.e6. [DOI: 10.1016/j.cub.2020.09.037] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/17/2020] [Accepted: 09/11/2020] [Indexed: 12/28/2022]
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