1
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Kumar M, Ayzenshtat D, Rather GA, Zemach H, Belausov E, Eshed Williams L, Bocobza S. A dynamic WUSCHEL/Layer 1 interplay directs shoot apical meristem formation during regeneration in tobacco. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 39215624 DOI: 10.1111/tpj.17002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 08/11/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024]
Abstract
De novo shoot apical meristem (SAM) organogenesis during regeneration in tissue culture has been investigated for several decades, but the precise mechanisms governing early-stage cell fate specification remain elusive. In contrast to SAM establishment during embryogenesis, in vitro SAM formation occurs without positional cues and is characterized by autonomous initiation of cellular patterning. Here, we report on the initial stages of SAM organogenesis and on the molecular mechanisms that orchestrate gene patterning to establish SAM homeostasis. We found that SAM organogenesis in tobacco calli starts with protuberance formation followed by the formation of an intact L1 layer covering the nascent protuberance. We also exposed a complex interdependent relationship between L1 and WUS expression and revealed that any disruption in this interplay compromises shoot formation. Silencing WUS in nascent protuberances prevented L1 formation and caused the disorganization of the outer cell layers exhibiting both anticlinal and periclinal divisions, suggesting WUS plays a critical role in the proper establishment and organization of L1 during SAM organogenesis. We further discovered that silencing TONNEAU1 prevents the exclusive occurrence of anticlinal divisions in the outermost layer of the protuberances and suppresses the acquisition of L1 cellular identity and L1 formation, ultimately impeding SAM formation and regeneration. This study provides a novel molecular framework for the characterization of a WUS/L1 interplay that mediates SAM formation during regeneration.
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Affiliation(s)
- Manoj Kumar
- Department of Ornamental Plants and Agricultural Biotechnology, The Institute of Plant Sciences, The Volcani Center, ARO, Rishon LeTsiyon, Israel
| | - Dana Ayzenshtat
- Department of Ornamental Plants and Agricultural Biotechnology, The Institute of Plant Sciences, The Volcani Center, ARO, Rishon LeTsiyon, Israel
| | - Gulzar A Rather
- Department of Ornamental Plants and Agricultural Biotechnology, The Institute of Plant Sciences, The Volcani Center, ARO, Rishon LeTsiyon, Israel
| | - Hanita Zemach
- Department of Ornamental Plants and Agricultural Biotechnology, The Institute of Plant Sciences, The Volcani Center, ARO, Rishon LeTsiyon, Israel
| | - Eduard Belausov
- Department of Ornamental Plants and Agricultural Biotechnology, The Institute of Plant Sciences, The Volcani Center, ARO, Rishon LeTsiyon, Israel
| | - Leor Eshed Williams
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Samuel Bocobza
- Department of Ornamental Plants and Agricultural Biotechnology, The Institute of Plant Sciences, The Volcani Center, ARO, Rishon LeTsiyon, Israel
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2
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Geng Y, Xie C, Yan A, Yang X, Lai DN, Liu X, Zhou Y. A conserved GRAS-domain transcriptional regulator links meristem indeterminacy to sex determination in Ceratopteris gametophytes. Curr Biol 2024; 34:3454-3472.e7. [PMID: 39059395 PMCID: PMC11364212 DOI: 10.1016/j.cub.2024.06.064] [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: 09/15/2023] [Revised: 05/16/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024]
Abstract
Most land plants alternate between generations of sexual gametophytes and asexual sporophytes. Unlike seed plants, fern gametophytes are free living and grow independently of their sporophytes. In homosporous ferns such as Ceratopteris, gametophytes derived from genetically identical spores exhibit sexual dimorphism, developing as either males or hermaphrodites. Males lack meristems and promote cell differentiation into sperm-producing antheridia. In contrast, hermaphrodites initiate multicellular meristems that stay undifferentiated, sustain cell division and prothallus expansion, and drive the formation of egg-producing archegonia. Once initiating the meristem, hermaphrodites secrete the pheromone antheridiogen, which triggers neighboring slower-growing gametophytes to develop as males, while the hermaphrodites themselves remain insensitive to antheridiogen. This strategy promotes outcrossing and prevents all individuals in the colony from becoming males. This study reveals that an evolutionarily conserved GRAS-domain transcriptional regulator (CrHAM), directly repressed by Ceratopteris microRNA171 (CrmiR171), promotes meristem development in Ceratopteris gametophytes and determines the male-to-hermaphrodite ratio in the colony. CrHAM preferentially accumulates within the meristems of hermaphrodites but is excluded from differentiated antheridia. CrHAM sustains meristem proliferation and cell division through conserved hormone pathways. In the meantime, CrHAM inhibits the antheridiogen-induced conversion of hermaphrodites to males by suppressing the male program expression and preventing meristem cells from differentiating into sperm-producing antheridia. This finding establishes a connection between meristem indeterminacy and sex determination in ferns, suggesting both conserved and diversified roles of meristem regulators in land plants.
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Affiliation(s)
- Yuan Geng
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Chong Xie
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - An Yan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Xi Yang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Dinh Nhan Lai
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Xing Liu
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA; Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA.
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3
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Li Q, Wang Y, Sun Z, Li H, Liu H. The Biosynthesis Process of Small RNA and Its Pivotal Roles in Plant Development. Int J Mol Sci 2024; 25:7680. [PMID: 39062923 PMCID: PMC11276867 DOI: 10.3390/ijms25147680] [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: 05/26/2024] [Revised: 07/01/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024] Open
Abstract
In the realm of plant biology, small RNAs (sRNAs) are imperative in the orchestration of gene expression, playing pivotal roles across a spectrum of developmental sequences and responses to environmental stressors. The biosynthetic cascade of sRNAs is characterized by an elaborate network of enzymatic pathways that meticulously process double-stranded RNA (dsRNA) precursors into sRNA molecules, typically 20 to 30 nucleotides in length. These sRNAs, chiefly microRNAs (miRNAs) and small interfering RNAs (siRNAs), are integral in guiding the RNA-induced silencing complex (RISC) to selectively target messenger RNAs (mRNAs) for post-transcriptional modulation. This regulation is achieved either through the targeted cleavage or the suppression of translational efficiency of the mRNAs. In plant development, sRNAs are integral to the modulation of key pathways that govern growth patterns, organ differentiation, and developmental timing. The biogenesis of sRNA itself is a fine-tuned process, beginning with transcription and proceeding through a series of processing steps involving Dicer-like enzymes and RNA-binding proteins. Recent advances in the field have illuminated the complex processes underlying the generation and function of small RNAs (sRNAs), including the identification of new sRNA categories and the clarification of their involvement in the intercommunication among diverse regulatory pathways. This review endeavors to evaluate the contemporary comprehension of sRNA biosynthesis and to underscore the pivotal role these molecules play in directing the intricate performance of plant developmental processes.
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Affiliation(s)
| | | | | | - Haiyang Li
- Guangdong Key Laboratory of Plant Adaptation and Molecular Design, Guangzhou Key Laboratory of Crop Gene Editing, Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (Q.L.); (Y.W.); (Z.S.)
| | - Huan Liu
- Guangdong Key Laboratory of Plant Adaptation and Molecular Design, Guangzhou Key Laboratory of Crop Gene Editing, Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou 510006, China; (Q.L.); (Y.W.); (Z.S.)
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4
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Demesa-Arevalo E, Narasimhan M, Simon R. Intercellular Communication in Shoot Meristems. ANNUAL REVIEW OF PLANT BIOLOGY 2024; 75:319-344. [PMID: 38424066 DOI: 10.1146/annurev-arplant-070523-035342] [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: 03/02/2024]
Abstract
The shoot meristem of land plants maintains the capacity for organ generation throughout its lifespan due to a group of undifferentiated stem cells. Most meristems are shaped like a dome with a precise spatial arrangement of functional domains, and, within and between these domains, cells interact through a network of interconnected signaling pathways. Intercellular communication in meristems is mediated by mobile transcription factors, small RNAs, hormones, and secreted peptides that are perceived by membrane-localized receptors. In recent years, we have gained deeper insight into the underlying molecular processes of the shoot meristem, and we discuss here how plants integrate internal and external inputs to control shoot meristem activities.
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Affiliation(s)
- Edgar Demesa-Arevalo
- Institute for Developmental Genetics, Heinrich Heine University, Düsseldorf, Germany;
| | - Madhumitha Narasimhan
- Institute for Developmental Genetics, Heinrich Heine University, Düsseldorf, Germany;
| | - Rüdiger Simon
- Institute for Developmental Genetics, Heinrich Heine University, Düsseldorf, Germany;
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5
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Uzair M, Urquidi Camacho RA, Liu Z, Overholt AM, DeGennaro D, Zhang L, Herron BS, Hong T, Shpak ED. An updated model of shoot apical meristem regulation by ERECTA family and CLAVATA3 signaling pathways in Arabidopsis. Development 2024; 151:dev202870. [PMID: 38814747 PMCID: PMC11234387 DOI: 10.1242/dev.202870] [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: 03/15/2024] [Accepted: 05/16/2024] [Indexed: 06/01/2024]
Abstract
The shoot apical meristem (SAM) gives rise to the aboveground organs of plants. The size of the SAM is relatively constant due to the balance between stem cell replenishment and cell recruitment into new organs. In angiosperms, the transcription factor WUSCHEL (WUS) promotes stem cell proliferation in the central zone of the SAM. WUS forms a negative feedback loop with a signaling pathway activated by CLAVATA3 (CLV3). In the periphery of the SAM, the ERECTA family receptors (ERfs) constrain WUS and CLV3 expression. Here, we show that four ligands of ERfs redundantly inhibit the expression of these two genes. Transcriptome analysis confirmed that WUS and CLV3 are the main targets of ERf signaling and uncovered new ones. Analysis of promoter reporters indicated that the WUS expression domain mostly overlaps with the CLV3 domain and does not shift along the apical-basal axis in clv3 mutants. Our three-dimensional mathematical model captured gene expression distributions at the single-cell level under various perturbed conditions. Based on our findings, CLV3 regulates cellular levels of WUS mostly through autocrine signaling, and ERfs regulate the spatial expression of WUS, preventing its encroachment into the peripheral zone.
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Affiliation(s)
- Muhammad Uzair
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | | | - Ziyi Liu
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA
| | - Alex M. Overholt
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Daniel DeGennaro
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Liang Zhang
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Brittani S. Herron
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Tian Hong
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA
| | - Elena D. Shpak
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, USA
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6
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Lindsay P, Swentowsky KW, Jackson D. Cultivating potential: Harnessing plant stem cells for agricultural crop improvement. MOLECULAR PLANT 2024; 17:50-74. [PMID: 38130059 DOI: 10.1016/j.molp.2023.12.014] [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: 10/14/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023]
Abstract
Meristems are stem cell-containing structures that produce all plant organs and are therefore important targets for crop improvement. Developmental regulators control the balance and rate of cell divisions within the meristem. Altering these regulators impacts meristem architecture and, as a consequence, plant form. In this review, we discuss genes involved in regulating the shoot apical meristem, inflorescence meristem, axillary meristem, root apical meristem, and vascular cambium in plants. We highlight several examples showing how crop breeders have manipulated developmental regulators to modify meristem growth and alter crop traits such as inflorescence size and branching patterns. Plant transformation techniques are another innovation related to plant meristem research because they make crop genome engineering possible. We discuss recent advances on plant transformation made possible by studying genes controlling meristem development. Finally, we conclude with discussions about how meristem research can contribute to crop improvement in the coming decades.
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Affiliation(s)
- Penelope Lindsay
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - David Jackson
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
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7
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Mishra S, Chaudhary R, Pandey B, Singh G, Sharma P. Genome-wide identification and expression analysis of the GRAS gene family under abiotic stresses in wheat (Triticum aestivum L.). Sci Rep 2023; 13:18705. [PMID: 37907517 PMCID: PMC10618205 DOI: 10.1038/s41598-023-45051-0] [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: 03/15/2023] [Accepted: 10/15/2023] [Indexed: 11/02/2023] Open
Abstract
The GRAS transcription factors are multifunctional proteins involved in various biological processes, encompassing plant growth, metabolism, and responses to both abiotic and biotic stresses. Wheat is an important cereal crop cultivated worldwide. However, no systematic study of the GRAS gene family and their functions under heat, drought, and salt stress tolerance and molecular dynamics modeling in wheat has been reported. In the present study, we identified the GRAS gene in Triticum aestivum through systematically performing gene structure analysis, chromosomal location, conserved motif, phylogenetic relationship, and expression patterns. A total of 177 GRAS genes were identified within the wheat genome. Based on phylogenetic analysis, these genes were categorically placed into 14 distinct subfamilies. Detailed analysis of the genetic architecture revealed that the majority of TaGRAS genes had no intronic regions. The expansion of the wheat GRAS gene family was proven to be influenced by both segmental and tandem duplication events. The study of collinearity events between TaGRAS and analogous orthologs from other plant species provided valuable insights into the evolution of the GRAS gene family in wheat. It is noteworthy that the promoter regions of TaGRAS genes consistently displayed an array of cis-acting elements that are associated with stress responses and hormone regulation. Additionally, we discovered 14 miRNAs that target key genes involved in three stress-responsive pathways in our study. Moreover, an assessment of RNA-seq data and qRT-PCR results revealed a significant increase in the expression of TaGRAS genes during abiotic stress. These findings highlight the crucial role of TaGRAS genes in mediating responses to different environmental stresses. Our research delved into the molecular dynamics and structural aspects of GRAS domain-DNA interactions, marking the first instance of such information being generated. Overall, the current findings contribute to our understanding of the organization of the GRAS genes in the wheat genome. Furthermore, we identified TaGRAS27 as a candidate gene for functional research, and to improve abiotic stress tolerance in the wheat by molecular breeding.
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Affiliation(s)
- Shefali Mishra
- Deenbandhu Chhotu Ram University of Science and Technology, Murthal, India
- ICAR-Indian Institute of Wheat and Barley Research, Agrasain Marg, PO BOX-158, Karnal, Haryana, India
| | - Reeti Chaudhary
- Deenbandhu Chhotu Ram University of Science and Technology, Murthal, India
| | - Bharti Pandey
- ICAR-National Dairy Research Institute, Karnal, India
| | - Gyanendra Singh
- ICAR-Indian Institute of Wheat and Barley Research, Agrasain Marg, PO BOX-158, Karnal, Haryana, India
| | - Pradeep Sharma
- ICAR-Indian Institute of Wheat and Barley Research, Agrasain Marg, PO BOX-158, Karnal, Haryana, India.
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8
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Bahafid E, Bradtmöller I, Thies AM, Nguyen TTON, Gutierrez C, Desvoyes B, Stahl Y, Blilou I, Simon RGW. The Arabidopsis SHORTROOT network coordinates shoot apical meristem development with auxin-dependent lateral organ initiation. eLife 2023; 12:e83334. [PMID: 37862096 PMCID: PMC10642969 DOI: 10.7554/elife.83334] [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: 09/08/2022] [Accepted: 09/29/2023] [Indexed: 10/21/2023] Open
Abstract
Plants produce new organs post-embryonically throughout their entire life cycle. This is due to stem cells present in the shoot and root apical meristems, the SAM and RAM, respectively. In the SAM, stem cells are located in the central zone where they divide slowly. Stem cell daughters are displaced laterally and enter the peripheral zone, where their mitotic activity increases and lateral organ primordia are formed. How the spatial arrangement of these different domains is initiated and controlled during SAM growth and development, and how sites of lateral organ primordia are determined in the peripheral zone is not yet completely understood. We found that the SHORTROOT (SHR) transcription factor together with its target transcription factors SCARECROW (SCR), SCARECROW-LIKE23 (SCL23) and JACKDAW (JKD), promotes formation of lateral organs and controls shoot meristem size. SHR, SCR, SCL23, and JKD are expressed in distinct, but partially overlapping patterns in the SAM. They can physically interact and activate expression of key cell cycle regulators such as CYCLIND6;1 (CYCD6;1) to promote the formation of new cell layers. In the peripheral zone, auxin accumulates at sites of lateral organ primordia initiation and activates SHR expression via the auxin response factor MONOPTEROS (MP) and auxin response elements in the SHR promoter. In the central zone, the SHR-target SCL23 physically interacts with the key stem cell regulator WUSCHEL (WUS) to promote stem cell fate. Both SCL23 and WUS expression are subject to negative feedback regulation from stem cells through the CLAVATA signaling pathway. Together, our findings illustrate how SHR-dependent transcription factor complexes act in different domains of the shoot meristem to mediate cell division and auxin dependent organ initiation in the peripheral zone, and coordinate this activity with stem cell maintenance in the central zone of the SAM.
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Affiliation(s)
- Elmehdi Bahafid
- Institute for Developmental Genetics, Heinrich Heine UniversityDüsseldorfGermany
| | - Imke Bradtmöller
- Institute for Developmental Genetics, Heinrich Heine UniversityDüsseldorfGermany
| | - Ann M Thies
- Institute for Developmental Genetics, Heinrich Heine UniversityDüsseldorfGermany
| | - Thi TON Nguyen
- Institute for Developmental Genetics, Heinrich Heine UniversityDüsseldorfGermany
| | - Crisanto Gutierrez
- Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, CantoblancoMadridSpain
| | - Bénédicte Desvoyes
- Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, CantoblancoMadridSpain
| | - Yvonne Stahl
- Institute for Developmental Genetics, Heinrich Heine UniversityDüsseldorfGermany
| | - Ikram Blilou
- Laboratory of Plant Cell and Developmental Biology, Division of Biological and Environmental Sciences and Engineering, 4700 King Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Rüdiger GW Simon
- Institute for Developmental Genetics, Heinrich Heine UniversityDüsseldorfGermany
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9
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Hong L, Fletcher JC. Stem Cells: Engines of Plant Growth and Development. Int J Mol Sci 2023; 24:14889. [PMID: 37834339 PMCID: PMC10573764 DOI: 10.3390/ijms241914889] [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: 09/09/2023] [Revised: 09/30/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
The development of both animals and plants relies on populations of pluripotent stem cells that provide the cellular raw materials for organ and tissue formation. Plant stem cell reservoirs are housed at the shoot and root tips in structures called meristems, with the shoot apical meristem (SAM) continuously producing aerial leaf, stem, and flower organs throughout the life cycle. Thus, the SAM acts as the engine of plant development and has unique structural and molecular features that allow it to balance self-renewal with differentiation and act as a constant source of new cells for organogenesis while simultaneously maintaining a stem cell reservoir for future organ formation. Studies have identified key roles for intercellular regulatory networks that establish and maintain meristem activity, including the KNOX transcription factor pathway and the CLV-WUS stem cell feedback loop. In addition, the plant hormones cytokinin and auxin act through their downstream signaling pathways in the SAM to integrate stem cell activity and organ initiation. This review discusses how the various regulatory pathways collectively orchestrate SAM function and touches on how their manipulation can alter stem cell activity to improve crop yield.
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Affiliation(s)
- Liu Hong
- Plant Gene Expression Center, United States Department of Agriculture—Agricultural Research Service, Albany, CA 94710, USA;
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jennifer C. Fletcher
- Plant Gene Expression Center, United States Department of Agriculture—Agricultural Research Service, Albany, CA 94710, USA;
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
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10
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Schrick K, Ahmad B, Nguyen HV. HD-Zip IV transcription factors: Drivers of epidermal cell fate integrate metabolic signals. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102417. [PMID: 37441837 PMCID: PMC10527651 DOI: 10.1016/j.pbi.2023.102417] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/14/2023] [Accepted: 06/14/2023] [Indexed: 07/15/2023]
Abstract
The leaf epidermis comprises the outermost layer of cells that protect plants against environmental stresses such as drought, ultraviolet radiation, and pathogen attack. Research over the past decades highlights the role of class IV homeodomain leucine-zipper (HD-Zip IV) transcription factors (TFs) in driving differentiation of various epidermal cell types, such as trichomes, guard cells, and pavement cells. Evolutionary origins of this family in the charophycean green algae and HD-Zip-specific gene expression in the maternal genome provide clues to unlocking their secrets which include ties to cell cycle regulation. A distinguishing feature of these TFs is the presence of a lipid binding pocket that integrates metabolic information with gene expression. Identities of metabolic partners are beginning to emerge, uncovering feedback loops to maintain epidermal cell specification. Discoveries of associated molecular mechanisms are revealing fascinating links to phospholipid and sphingolipid metabolism and mechanical signaling.
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Affiliation(s)
- Kathrin Schrick
- Molecular, Cellular, and Developmental Biology, Kansas State University, Manhattan, KS 66506, USA; Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Bilal Ahmad
- Molecular, Cellular, and Developmental Biology, Kansas State University, Manhattan, KS 66506, USA; Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Hieu V Nguyen
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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11
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Wang Y, Jiao Y. Cell signaling in the shoot apical meristem. PLANT PHYSIOLOGY 2023; 193:70-82. [PMID: 37224874 DOI: 10.1093/plphys/kiad309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/24/2023] [Accepted: 05/10/2023] [Indexed: 05/26/2023]
Abstract
Distinct from animals, plants maintain organogenesis from specialized tissues termed meristems throughout life. In the shoot apex, the shoot apical meristem (SAM) produces all aerial organs, such as leaves, from its periphery. For this, the SAM needs to precisely balance stem cell renewal and differentiation, which is achieved through dynamic zonation of the SAM, and cell signaling within functional domains is key for SAM functions. The WUSCHEL-CLAVATA feedback loop plays a key role in SAM homeostasis, and recent studies have uncovered new components, expanding our understanding of the spatial expression and signaling mechanism. Advances in polar auxin transport and signaling have contributed to knowledge of the multifaceted roles of auxin in the SAM and organogenesis. Finally, single-cell techniques have expanded our understanding of the cellular functions within the shoot apex at single-cell resolution. In this review, we summarize the most up-to-date understanding of cell signaling in the SAM and focus on the multiple levels of regulation of SAM formation and maintenance.
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Affiliation(s)
- Ying Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuling Jiao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang, Shandong 261325, China
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12
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Xu W, Fan H, Pei X, Hua X, Xu T, He Q. mRNA-Seq and miRNA-Seq Analyses Provide Insights into the Mechanism of Pinellia ternata Bulbil Initiation Induced by Phytohormones. Genes (Basel) 2023; 14:1727. [PMID: 37761867 PMCID: PMC10531394 DOI: 10.3390/genes14091727] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
Pinellia ternata (Thunb.) Breit (abbreviated as P. ternata) is a plant with an important medicinal value whose yield is restricted by many factors, such as low reproductive efficiency and continuous cropping obstacles. As an essential breeding material for P. ternata growth and production, the bulbils have significant advantages such as a high survival rate and short breeding cycles. However, the location effect, influencing factors, and molecular mechanism of bulbil occurrence and formation have not been fully explored. In this study, exogenously applied phytohormones were used to induce in vitro petiole of P. ternata to produce bulbil structure. Transcriptome sequencing of mRNA and miRNA were performed in the induced petiole (TCp) and the induced bulbil (TCb). Gene Ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed for the identification of key genes and pathways involved in bulbil development. A total of 58,019 differentially expressed genes (DEGs) were identified. The GO and KEGG analysis indicated that DEGs were mainly enriched in plant hormone signal transduction and the starch and sucrose metabolism pathway. The expression profiles of miR167a, miR171a, and miR156a during bulbil induction were verified by qRT-PCR, indicating that these three miRNAs and their target genes may be involved in the process of bulbil induction and play an important role. However, further molecular biological experiments are required to confirm the functions of the identified bulbil development-related miRNAs and targets.
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Affiliation(s)
- Wenxin Xu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (W.X.); (H.F.); (X.P.); (X.H.)
| | - Haoyu Fan
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (W.X.); (H.F.); (X.P.); (X.H.)
| | - Xiaomin Pei
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (W.X.); (H.F.); (X.P.); (X.H.)
| | - Xuejun Hua
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (W.X.); (H.F.); (X.P.); (X.H.)
| | - Tao Xu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; (W.X.); (H.F.); (X.P.); (X.H.)
| | - Qiuling He
- Laboratory of Plant Secondary Metabolism and Regulation of Zhejiang Province, Hangzhou 310018, China
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13
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Pei LL, Zhang LL, Liu X, Jiang J. Role of microRNA miR171 in plant development. PeerJ 2023; 11:e15632. [PMID: 37456878 PMCID: PMC10340099 DOI: 10.7717/peerj.15632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/02/2023] [Indexed: 07/18/2023] Open
Abstract
MicroRNAs (miRNAs) are endogenous non-coding small RNA with 19-24 nucleotides (nts) in length, which play an essential role in regulating gene expression at the post-transcriptional level. As one of the first miRNAs found in plants, miR171 is a typical class of conserved miRNAs. The miR171 sequences among different species are highly similar, and the vast majority of them have both "GAGCCG" and "CAAUAU" fragments. In addition to being involved in plant growth and development, hormone signaling and stress response, miR171 also plays multiple and important roles in plants through interactions with microbe and other small-RNAs. The miRNA functions by regulating the expression of target genes. Most of miR171's target genes are in the GRAS gene family, but also include some NSP, miRNAs, lncRNAs, and other genes. This review is intended to summarize recent updates on miR171 regarding its function in plant life and hopefully provide new ideas for understanding miR171 function and regulatory mechanisms.
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Affiliation(s)
- Ling Ling Pei
- College of Horticulture, Shenyang Agricultural University, Shenyang, Shenhe District, China
| | - Ling Ling Zhang
- College of Horticulture, Shenyang Agriculture University, Shenyang, Shenhe District, China
| | - Xin Liu
- Horticulture Department, Shenyang Agricultural University, Shenyang, Shenhe District, China
| | - Jing Jiang
- Horticulture Department, Shenyang Agricultural University, Shenyang, Shenhe District, China
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14
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Nagata K, Abe M. A conserved mechanism determines the activity of two pivotal transcription factors that control epidermal cell differentiation in Arabidopsis thaliana. JOURNAL OF PLANT RESEARCH 2023; 136:349-358. [PMID: 36826609 PMCID: PMC10126025 DOI: 10.1007/s10265-023-01439-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 02/01/2023] [Indexed: 05/25/2023]
Abstract
The surface of plants is covered by the epidermis, which protects the plant's body from the external environment and mediates inter-cell layer signaling to regulate plant development. Therefore, the manifestation of epidermal traits at a precise location is a prerequisite for their normal growth and development. In Arabidopsis thaliana, class IV homeodomain-leucine zipper transcription factors PROTODERMAL FACTOR2 (PDF2) and ARABIDOPSIS THALIANA MERISTEM LAYER1 (ATML1) play redundant roles in epidermal cell differentiation. Nevertheless, several pieces of evidence suggest that the activity and/or function of PDF2 and ATML1 are regulated differently. The role of the steroidogenic acute regulatory protein-related lipid transfer (START) domain of ATML1 in restricting this protein's activity has been demonstrated; however, whether this lipid-dependent mechanism regulates PDF2 expression is unknown. In this study, we demonstrated that the START domains of PDF2 and ATML1, regulate protein turnover in a position-dependent manner and affect the dimeric proteins. Our results show that a conserved mechanism provides the basis for the functional redundancy of PDF2 and ATML1 in epidermal cell differentiation and that an unidentified regulatory layer specific to PDF2 or ATML1 is responsible for the difference in the activity and/or function of PDF2 and ATML1.
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Affiliation(s)
- Kenji Nagata
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro-Ku, Tokyo, 153-8902, Japan
| | - Mitsutomo Abe
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro-Ku, Tokyo, 153-8902, Japan.
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15
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Castricum A, Bakker EH, de Vetten NCMH, Weemen M, Angenent GC, Immink RGH, Bemer M. HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum. Int J Mol Sci 2023; 24:ijms24087655. [PMID: 37108818 PMCID: PMC10141471 DOI: 10.3390/ijms24087655] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/12/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Chrysanthemum is a genus in the Asteraceae family containing numerous cut flower varieties with high ornamental value. It owes its beauty to the composite flower head, which resembles a compact inflorescence. This structure is also known as a capitulum, in which many ray and disc florets are densely packed. The ray florets are localized at the rim, are male sterile, and have large colorful petals. The centrally localized disc florets develop only a small petal tube but produce fertile stamens and a functional pistil. Nowadays, varieties with more ray florets are bred because of their high ornamental value, but, unfortunately, this is at the expense of their seed setting. In this study, we confirmed that the disc:ray floret ratio is highly correlated to seed set efficiency, and therefore, we further investigated the mechanisms that underlie the regulation of the disc:ray floret ratio. To this end, a comprehensive transcriptomics analysis was performed in two acquired mutants with a higher disc:ray floret ratio. Among the differentially regulated genes, various potential brassinosteroid (BR) signaling genes and HD-ZIP class IV homeodomain transcription factors stood out. Detailed follow-up functional studies confirmed that reduced BR levels and downregulation of HD-ZIP IV gene Chrysanthemum morifolium PROTODERMAL FACTOR 2 (CmPDF2) result in an increased disc:ray floret ratio, thereby providing ways to improve seed set in decorative chrysanthemum varieties in the future.
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Affiliation(s)
- Annemarie Castricum
- Bioscience, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
- Dekker Chrysanten, 1711 RP Hensbroek, The Netherlands
| | - Erin H Bakker
- Dekker Chrysanten, 1711 RP Hensbroek, The Netherlands
| | | | - Mieke Weemen
- Bioscience, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
| | - Gerco C Angenent
- Bioscience, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
| | - Richard G H Immink
- Bioscience, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
| | - Marian Bemer
- Bioscience, Wageningen University & Research, 6700 AA Wageningen, The Netherlands
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16
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Wang L, Hou J, Xu H, Zhang Y, Huang R, Wang D, He XQ. The PtoTCP20-miR396d-PtoGRF15 module regulates secondary vascular development in Populus. PLANT COMMUNICATIONS 2023; 4:100494. [PMID: 36419363 PMCID: PMC10030372 DOI: 10.1016/j.xplc.2022.100494] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 09/07/2022] [Accepted: 11/18/2022] [Indexed: 05/04/2023]
Abstract
Secondary vascular development is a key biological characteristic of woody plants and the basis of wood formation. Our understanding of gene expression regulation and dynamic changes in microRNAs (miRNAs) during secondary vascular development is still limited. Here we present an integrated analysis of the miRNA and mRNA transcriptome of six phase-specific tissues-the shoot apex, procambium, primary vascular tissue, cambium, secondary phloem, and secondary xylem-in Populus tomentosa. Several novel regulatory modules, including the PtoTCP20-miR396d-PtoGRF15 module, were identified during secondary vascular development in Populus. A series of biochemical and molecular experiments confirmed that PtoTCP20 activated transcription of the miR396d precursor gene and that miR396d targeted PtoGRF15 to downregulate its expression. Plants overexpressing miR396d (35S:miR396d) showed enhanced secondary growth and increased xylem production. Conversely, during the transition from primary to secondary vascular development, plants with downregulated PtoTCP20expression (PtoTCP20-SRDX), downregulated miR396 expression (35S:STTM396), and PtoGRF15 overexpression (35S:PtoGRF15) showed delayed secondary growth. Novel regulatory modules were identified by integrated analysis of the miRNA and mRNA transcriptome, and the regulatory role of the PtoTCP20-miR396d-PtoGRF15 signaling cascade in secondary vascular development was validated in Populus, providing information to support improvements in forest cultivation and wood properties.
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Affiliation(s)
- Lingyan Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Jie Hou
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Huimin Xu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China; College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yufei Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Runzhou Huang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Donghui Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Xin-Qiang He
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
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17
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Shi Q, Tian D, Wang J, Chen A, Miao Y, Chen Y, Li J, Wu X, Zheng B, Guo W, Shi X. Overexpression of miR390b promotes stem elongation and height growth in Populus. HORTICULTURE RESEARCH 2023; 10:uhac258. [PMID: 36778185 PMCID: PMC9907050 DOI: 10.1093/hr/uhac258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/18/2022] [Indexed: 06/18/2023]
Abstract
MicroRNA390 (miR390) is involved in plant growth and development by down-regulating the expression of the downstream genes trans-acting short interfering RNA3 (TAS3) and AUXIN RESPONSE FACTORs (ARFs). There is a scarcity of research on the involvement of the miR390-TAS3-ARFs pathway in the stem development of Populus. Here, differentially expressed miRNAs during poplar stem development were screened by small RNA sequencing analysis, and a novel function of miR390b in stem development was revealed. Overexpression of miR390b (OE-miR390b) resulted in a large increase in the number of xylem fiber cells and a slight decrease in the cell length at the longitudinal axis. Overall increases in stem elongation and plant height were observed in the OE-miR390b plants. According to transcriptome sequencing results and transient co-expression analysis, TAS3.1 and TAS3.2 were identified as the target genes of miR390 in poplar and were negatively regulated by miR390 in the apex. The transcription levels of ARF3.2 and ARF4 were significantly repressed in OE-miR390b plants and strongly negatively correlated with the number of xylem fiber cells along the longitudinal axis. These findings indicate that the conserved miR390-TAS3-ARFs pathway in poplar is involved in stem elongation and plant height growth.
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Affiliation(s)
- Qiaofang Shi
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
- Poplar Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Dongdong Tian
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Jieyu Wang
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
- Poplar Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Aoli Chen
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Yuqing Miao
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Yiming Chen
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
- Poplar Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Jun Li
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
- Poplar Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiaomeng Wu
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Bo Zheng
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
- Poplar Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenwu Guo
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
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18
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Wu X, Liu X, Zhang S, Zhou Y. Cell Division and Meristem Dynamics in Fern Gametophytes. PLANTS (BASEL, SWITZERLAND) 2023; 12:209. [PMID: 36616337 PMCID: PMC9823664 DOI: 10.3390/plants12010209] [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: 12/08/2022] [Revised: 12/31/2022] [Accepted: 12/31/2022] [Indexed: 06/17/2023]
Abstract
One of the most important questions in all multicellular organisms is how to define and maintain different cell fates during continuous cell division and proliferation. Plant meristems provide a unique research system to address this fundamental question because meristems dynamically maintain themselves and sustain organogenesis through balancing cell division and cell differentiation. Different from the gametophytes of seed plants that depend on their sporophytes and lack meristems, the gametophytes of seed-free ferns develop different types of meristems (including apical cell-based meristems and multicellular apical and marginal meristems) to promote independent growth and proliferation during the sexual gametophyte phase. Recent studies combining confocal time-lapse imaging and computational image analysis reveal the cellular basis of the initiation and proliferation of different types of meristems in fern gametophytes, providing new insights into the evolution of meristems in land plants. In this review, we summarize the recent progress in understanding the cell growth dynamics in fern gametophytes and discuss both conserved and diversified mechanisms underlying meristem cell proliferation in seed-free vascular plants.
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Affiliation(s)
- Xiao Wu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Xing Liu
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Shaoling Zhang
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
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19
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Minow MAA, Coneva V, Lesy V, Misyura M, Colasanti J. Plant gene silencing signals move from the phloem to influence gene expression in shoot apical meristems. BMC PLANT BIOLOGY 2022; 22:606. [PMID: 36550422 PMCID: PMC9783409 DOI: 10.1186/s12870-022-03998-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Small RNAs (sRNA) are potent regulators of gene expression that can diffuse short distances between cells and move long distances through plant vasculature. However, the degree to which sRNA silencing signals can move from the phloem to the shoot apical meristem (SAM) remains unclear. RESULTS Two independent transgenic approaches were used to examine whether phloem sRNA silencing can reach different domains of the SAM and silence SAM-expressed genes. First, the phloem companion-cell specific SUCROSE-PROTON SYMPORTER2 (SUC2) promoter was used to drive expression of an inverted repeat to target the FD gene, an exclusively SAM-localized floral regulator. Second, the SUC2 promoter was used to express an artificial microRNA (aMiR) designed to target a synthetic CLAVATA3 (CLV3) transgene in SAM stem cells. Both phloem silencing signals phenocopied the loss of function of their targets and altered target gene expression suggesting that a phloem-to-SAM silencing communication axis exists, connecting distal regions of the plant to SAM stem cells. CONCLUSIONS Demonstration of phloem-to-SAM silencing reveals a regulatory link between somatic sRNA expressed in distal regions of the plant and the growing shoot. Since the SAM stem cells ultimately produce the gametes, we discuss the intriguing possibility that phloem-to-SAM sRNA trafficking could allow transient somatic sRNA expression to manifest stable, transgenerational epigenetic changes.
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Affiliation(s)
- Mark A. A. Minow
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East Guelph, Ontario, Canada
| | - Viktoriya Coneva
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East Guelph, Ontario, Canada
| | - Victoria Lesy
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East Guelph, Ontario, Canada
| | - Max Misyura
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East Guelph, Ontario, Canada
| | - Joseph Colasanti
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East Guelph, Ontario, Canada
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20
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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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21
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The NGATHA-like Genes DPA4 and SOD7 Are Not Required for Stem Cell Specification during Embryo Development in Arabidopsis thaliana. Int J Mol Sci 2022; 23:ijms231912007. [PMID: 36233309 PMCID: PMC9569844 DOI: 10.3390/ijms231912007] [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: 09/16/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 01/09/2023] Open
Abstract
In plants, stem cells are embedded in structures called meristems. Meristems can be formed either during embryogenesis or during the plant's life such as, for instance, axillary meristems. While the regulation of the stem cell population in an established meristem is well described, how it is initiated in newly formed meristems is less well understood. Recently, two transcription factors of the NGATHA-like family, DEVELOPMENT-RELATED PcG TARGET IN THE APEX4 (DPA4)/NGAL3 and SUPPRESSOR OF DA1-1 7 (SOD7)/NGAL2 have been shown to facilitate de novo stem cell initiation in Arabidopsis thaliana axillary meristems. Here, we tested whether the DPA4 and SOD7 genes had a similar role during stem cell formation in embryo shoot apical meristems. Using DPA4 and SOD7 reporter lines, we characterized the expression pattern of these genes during embryo development, revealing only a partial overlap with the stem cell population. In addition, we showed that the expression of a stem cell reporter was not modified in dpa4-2 sod7-2 double mutant embryos compared to the wild type. Together, these observations suggest that DPA4 and SOD7 are not required for stem cell specification during embryo shoot apical meristem initiation. This work stresses the difference in the regulatory network leading to meristem formation during the embryonic and post-embryonic phases.
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22
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Xiong F, Ren JJ, Wang YY, Zhou Z, Qi HD, Otegui MS, Wang XL. An Arabidopsis Retention and Splicing complex regulates root and embryo development through pre-mRNA splicing. PLANT PHYSIOLOGY 2022; 190:621-639. [PMID: 35640107 PMCID: PMC9434225 DOI: 10.1093/plphys/kiac256] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 05/08/2022] [Indexed: 05/30/2023]
Abstract
Pre-mRNA splicing is an important step in the posttranscriptional processing of transcripts and a key regulator of development. The heterotrimeric retention and splicing (RES) complex plays vital roles in the growth and development of yeast, zebrafish, and humans by mediating pre-mRNA splicing of multiple genes. However, whether the RES complex is conserved in plants and what specific functions it has remain unknown. In this study, we identified Arabidopsis (Arabidopsis thaliana) BUD13 (AtBUD13), GROWTH, DEVELOPMENT AND SPLICING 1 (GDS1), and DAWDLE (DDL) as the counterparts of the yeast RES complex subunits Bud site selection protein 13 (Bud13), U2 snRNP component Snu17 (Snu17), and Pre-mRNA leakage protein 1, respectively. Moreover, we showed that RES is an ancient complex evolutionarily conserved in eukaryotes. GDS1 directly interacts with both AtBUD13 and DDL in nuclear speckles. The BUD13 domain of AtBUD13 and the RNA recognition motif domain of GDS1 are necessary and sufficient for AtBUD13-GDS1 interaction. Mutants of AtBUD13, GDS1, and DDL failed to properly splice multiple genes involved in cell proliferation and showed defects in early embryogenesis and root development. In addition, we found that GDS1 and DDL interact, respectively, with the U2 small nuclear ribonucleoproteins auxiliary factor AtU2AF65B and the NineTeen Complex-related splicing factor SKIP, which are essential for early steps of spliceosome assembly and recognition of splice sites. Altogether, our work reveals that the Arabidopsis RES complex is important for root and early embryo development by modulating pre-mRNA splicing.
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Affiliation(s)
- Feng Xiong
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Jing-Jing Ren
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Yu-Yi Wang
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Zhou Zhou
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Hao-Dong Qi
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Marisa S Otegui
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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23
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Geng Y, Yan A, Zhou Y. Positional cues and cell division dynamics drive meristem development and archegonium formation in Ceratopteris gametophytes. Commun Biol 2022; 5:650. [PMID: 35778477 PMCID: PMC9249879 DOI: 10.1038/s42003-022-03627-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 06/22/2022] [Indexed: 11/17/2022] Open
Abstract
Fern gametophytes are autotrophic and independent of sporophytes, and they develop pluripotent meristems that drive prothallus development and sexual reproduction. To reveal cellular dynamics during meristem development in fern gametophytes, we performed long-term time-lapse imaging and determined the real-time lineage, identity and division activity of each single cell from meristem initiation to establishment in gametophytes of the fern Ceratopteris richardii. Our results demonstrate that in Ceratopteris gametophytes, only a few cell lineages originated from the marginal layer contribute to meristem initiation and proliferation, and the meristem lacks a distinguishable central zone or apical cell with low division activity. Within the meristem, cell division is independent of cell lineages and cells at the marginal layer are more actively dividing than inner cells. Furthermore, the meristem triggers differentiation of adjacent cells into egg-producing archegonia in a position-dependent manner. These findings advance the understanding of diversified meristem and gametophyte development in land plants. Time-lapse imaging of the fern Ceratopteris richardii during meristem initiation and proliferation provides insights into the lineage, identity and division activity of each cell throughout the growth of gametophytes.
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Affiliation(s)
- Yuan Geng
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.,Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - An Yan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA. .,Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA.
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24
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Shi QF, Long JM, Yin ZP, Jiang N, Feng MQ, Zheng B, Guo WW, Wu XM. miR171 modulates induction of somatic embryogenesis in citrus callus. PLANT CELL REPORTS 2022; 41:1403-1415. [PMID: 35381869 DOI: 10.1007/s00299-022-02865-y] [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: 11/30/2021] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
Overexpression of miR171 restored SE competence in the recalcitrant citrus callus, and inhibition of miR171 function weakened SE competence in the strongly embryogenic citrus callus. Somatic embryogenesis (SE) is an important way of in vitro regeneration for plants. For perennial woody crops such as citrus, embryogenic callus is usually induced from unfertilized aborted ovules and widely used in biotechnology aided breeding. However, SE capacity always declines in callus during subculture, which makes regeneration difficult and hinders the application of biotechnology. We previously found that miR171 may be a regulator of SE in citrus, based on the abundant expression of csi-miR171c in the embryogenic callus and during SE of citrus. Here, we report that miR171 promotes SE and is required for SE in citrus. Overexpression of miR171 restored SE competence in the recalcitrant callus of 'Guoqing No.1' Satsuma mandarin (G1), whereas inhibition of miR171 function by Short Tandem Target Mimic (STTM) weakened SE competence in the strongly embryogenic callus of 'Valencia' sweet orange (V). The comparative transcriptomic analysis in miR171 overexpressed callus line (OE) and the wild type callus (WT) indicated that overexpression of miR171 decreased the expression level of its SCARECROW-LIKE (CsSCL) targets, and activated stress response related biological processes and metabolic processes that are required for cell differentiation. However, CsSCLs were up-regulated in the OE callus during SE induction process, which activated the cell division and developmental processes that are required for embryogenesis progress. Our results validate the function of miR171 in regulation of SE and reveal the biological responses provoked by miR171 in citrus that may promote SE.
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Affiliation(s)
- Qiao-Fang Shi
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jian-Mei Long
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China
| | - Zhao-Ping Yin
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Nan Jiang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Meng-Qi Feng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Bo Zheng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wen-Wu Guo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Xiao-Meng Wu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China.
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25
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Wong A, Gehring C. New Horizons in Plant Cell Signaling. Int J Mol Sci 2022; 23:5826. [PMID: 35628641 PMCID: PMC9147848 DOI: 10.3390/ijms23105826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 05/13/2022] [Indexed: 12/04/2022] Open
Abstract
Responding to environmental stimuli with appropriate molecular mechanisms is essential to all life forms and particularly so in sessile organisms such as plants [...].
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Affiliation(s)
- Aloysius Wong
- Department of Biology, College of Science and Technology, Wenzhou-Kean University, 88 Daxue Road, Wenzhou 325060, China
- Zhejiang Bioinformatics International Science and Technology Cooperation Center, Wenzhou 325060, China
- Wenzhou Municipal Key Lab for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou 325060, China
| | - Christoph Gehring
- Department of Chemistry, Biology & Biotechnology, University of Perugia, Borgo XX Giugno, 74, 06121 Perugia, Italy
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26
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Nicolas A, Laufs P. Meristem Initiation and de novo Stem Cell Formation. FRONTIERS IN PLANT SCIENCE 2022; 13:891228. [PMID: 35557739 PMCID: PMC9087721 DOI: 10.3389/fpls.2022.891228] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Plant aerial development relies on meristem activity which ensures main body plant axis development during plant life. While the shoot apical meristem (SAM) formed in the embryo only contributes to the main stem, the branched structure observed in many plants relies on axillary meristems (AMs) formed post-embryonically. These AMs initiate from a few cells of the leaf axil that retain meristematic characteristics, increase in number, and finally organize into a structure similar to the SAM. In this review, we will discuss recent findings on de novo establishment of a stem cell population and its regulatory niche, a key step essential for the indeterminate fate of AMs. We stress that de novo stem cell formation is a progressive process, which starts with a transient regulatory network promoting stem cell formation and that is different from the one acting in functional meristems. This transient stage can be called premeristems and we discuss whether this concept can be extended to the formation of meristems other than AMs.
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Affiliation(s)
- Antoine Nicolas
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
- Université Paris-Saclay, Orsay, France
| | - Patrick Laufs
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
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27
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Shimotohno A. Illuminating the molecular mechanisms underlying shoot apical meristem homeostasis in plants. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2022; 39:19-28. [PMID: 35800970 PMCID: PMC9200092 DOI: 10.5511/plantbiotechnology.22.0213a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/13/2022] [Indexed: 05/15/2023]
Abstract
Unlike animals, terrestrial plants are sessile and able to give rise to new organs throughout their lifetime. In the most extreme cases, they can survive for over a thousand years. With such protracted life cycles, plants have evolved sophisticated strategies to adapt to variable environments by coordinating their morphology as well as their growth, and have consequently acquired a high degree of developmental plasticity, which is supported by small groups of long-lived stem cells found in proliferative centers called meristems. Shoot apical meristems (SAMs) contain multipotent stem cells and provide a microenvironment that ensures both a self-renewable reservoir, to produce primordia and sustain growth, and a differentiating population that develops into all of the above-ground organs of land plants. The homeodomain transcription factor WUSCHEL (WUS) is expressed in the organizing center and acts as a master regulator to govern shoot stem cell homeostasis. In this review, I highlight recent advances in our understanding of the molecular mechanisms and signaling networks that underlie SAM maintenance, and discuss how plants utilize WUS to integrate intrinsic and extrinsic cues.
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Affiliation(s)
- Akie Shimotohno
- Institute of Transformative Bio-Molecules, Nagoya University, Nagoya, Aichi 464-8601, Japan
- E-mail: Tel: +81-52-789-2841 Fax: +81-52-789-3240
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28
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Han H, Zhou Y. Function and Regulation of microRNA171 in Plant Stem Cell Homeostasis and Developmental Programing. Int J Mol Sci 2022; 23:2544. [PMID: 35269685 PMCID: PMC8910752 DOI: 10.3390/ijms23052544] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 12/17/2022] Open
Abstract
MicroRNA171 (miR171), a group of 21-nucleotide single-strand small RNAs, is one ancient and conserved microRNA family in land plants. This review focuses on the recent progress in understanding the role of miR171 in plant stem cell homeostasis and developmental patterning, and the regulation of miR171 by developmental cues and environmental signals. Specifically, miR171 regulates shoot meristem activity and phase transition through repressing the HAIRYMERISTEM (HAM) family genes. In the model species Arabidopsis, miR171 serves as a short-range mobile signal, which initiates in the epidermal layer of shoot meristems and moves downwards within a limited distance, to pattern the apical-basal polarity of gene expression and drive stem cell dynamics. miR171 levels are regulated by light and various abiotic stresses, suggesting miR171 may serve as a linkage between environmental factors and cell fate decisions. Furthermore, miR171 family members also demonstrate both conserved and lineage-specific functions in land plants, which are summarized and discussed here.
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Affiliation(s)
- Han Han
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA;
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA;
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
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29
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Li L, Garsamo M, Yuan J, Wang X, Lam SH, Varala K, Boavida LC, Zhou Y, Liu X. CAND1 is required for pollen viability in Arabidopsis thaliana-a test of the adaptive exchange hypothesis. FRONTIERS IN PLANT SCIENCE 2022; 13:866086. [PMID: 35968124 PMCID: PMC9366119 DOI: 10.3389/fpls.2022.866086] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/04/2022] [Indexed: 05/11/2023]
Abstract
The dynamic assembly of SKP1•CUL1•F-box protein (SCF) ubiquitin ligases is important for protein ubiquitination and degradation. This process is enabled by CAND1, which exchanges F-box proteins associated with the common CUL1 scaffold, and thereby, recycles the limited CUL1 core and allows diverse F-box proteins to assemble active SCFs. Previous human cell biological and computational studies have led to the adaptive exchange hypothesis, which suggests that the CAND1-mediated exchange confers plasticity on the SCF system, allowing cells to tolerate large variations in F-box protein expression. Here, we tested this hypothesis using Arabidopsis thaliana, a multicellular organism expressing hundreds of F-box protein genes at variable levels in different tissues. The cand1 null mutant in Arabidopsis is viable but produce almost no seeds. Bioinformatic, cell biological, and developmental analyses revealed that the low fertility in the cand1 mutant is associated with cell death in pollen, where the net expression of F-box protein genes is significantly higher than any other Arabidopsis tissue. In addition, we show that the transmission efficiency of the cand1 null allele was reduced through the male but not the female gametophyte. Our results suggest that CAND1 activity is essential in cells or tissues expressing high levels of F-box proteins. This finding is consistent with the proposed adaptive exchange hypothesis, demonstrating the necessity of the evolutionarily conserved CAND1-mediated exchange system in the development of a multicellular organism.
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Affiliation(s)
- Lihong Li
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Melaku Garsamo
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Jing Yuan
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Xiaojin Wang
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, United States
| | - Susan H. Lam
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Kranthi Varala
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, United States
| | - Leonor C. Boavida
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Yun Zhou
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Xing Liu
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- *Correspondence: Xing Liu,
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30
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Geng Y, Zhou Y. N-terminal region is required for functions of the HAM family member. PLANT SIGNALING & BEHAVIOR 2021; 16:1940001. [PMID: 34152254 PMCID: PMC8331016 DOI: 10.1080/15592324.2021.1940001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/02/2021] [Accepted: 06/03/2021] [Indexed: 05/29/2023]
Abstract
Shoot meristems contain stem cells, and they sustain growth and development of the above-ground tissues in land plants. The HAIRY MERISTEM (HAM) family genes, encoding GRAS-domain transcriptional regulators, play essential roles in the control of shoot meristem development and stem cell homeostasis in several flowering plants. Similar to other GRAS proteins, the C-terminal regions of HAM family proteins across land plants are conserved, containing signature motifs that define the GRAS domain. In contrast, the N-terminal regions of HAM family proteins display substantial divergence in sequence and length. Whether the variable and divergent N-termini are required for the conserved functions of HAM proteins is unknown. Our recent work showed that CrHAM - the HAM homolog in the fern Ceratopteris richardii was able to replace the role of type-II HAM genes in Arabidopsis, maintaining established shoot apical meristems and promoting the initiation of new stem cell niches. Here, we provide additional information and show that CrHAM contains a much longer N-terminal region compared to Arabidopsis HAM proteins, which is conserved among different fern HAM homologs. The deletion of this region largely compromises the ability of CrHAM to replace the function of Arabidopsis HAM proteins in shoot meristems. These new data together with previous results suggest that, although lacking the sequence conservation among HAM homologs from different plant lineages, the N-termini are important for the conserved functions of HAM family proteins.
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Affiliation(s)
- Yuan Geng
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, USA
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, USA
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31
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Abstract
Plants exhibit remarkable lineage plasticity, allowing them to regenerate organs that differ from their respective origins. Such developmental plasticity is dependent on the activity of pluripotent founder cells or stem cells residing in meristems. At the shoot apical meristem (SAM), the constant flow of cells requires continuing cell specification governed by a complex genetic network, with the WUSCHEL transcription factor and phytohormone cytokinin at its core. In this review, I discuss some intriguing recent discoveries that expose new principles and mechanisms of patterning and cell specification acting both at the SAM and, prior to meristem organogenesis during shoot regeneration. I also highlight unanswered questions and future challenges in the study of SAM and meristem regeneration. Finally, I put forward a model describing stochastic events mediated by epigenetic factors to explain how the gene regulatory network might be initiated at the onset of shoot regeneration. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Leor Eshed Williams
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel;
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32
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Brioudes F, Jay F, Sarazin A, Grentzinger T, Devers EA, Voinnet O. HASTY, the Arabidopsis EXPORTIN5 ortholog, regulates cell-to-cell and vascular microRNA movement. EMBO J 2021; 40:e107455. [PMID: 34152631 PMCID: PMC8327949 DOI: 10.15252/embj.2020107455] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 05/04/2021] [Accepted: 05/07/2021] [Indexed: 01/04/2023] Open
Abstract
Plant microRNAs (miRNAs) guide cytosolic post-transcriptional gene silencing of sequence-complementary transcripts within the producing cells, as well as in distant cells and tissues. Here, we used an artificial miRNA-based system (amiRSUL) in Arabidopsis thaliana to explore the still elusive mechanisms of inter-cellular miRNA movement via forward genetics. This screen identified many mutant alleles of HASTY (HST), the ortholog of mammalian EXPORTIN5 (XPO5) with a recently reported role in miRNA biogenesis in Arabidopsis. In both epidermis-peeling and grafting assays, amiRSUL levels were reduced much more substantially in miRNA-recipient tissues than in silencing-emitting tissues. We ascribe this effect to HST controlling cell-to-cell and phloem-mediated movement of the processed amiRSUL, in addition to regulating its biogenesis. While HST is not required for the movement of free GFP or siRNAs, its cell-autonomous expression in amiRSUL-emitting tissues suffices to restore amiRSUL movement independently of its nucleo-cytosolic shuttling activity. By contrast, HST is dispensable for the movement and activity of amiRSUL within recipient tissues. Finally, HST enables movement of endogenous miRNAs that display mostly unaltered steady-state levels in hst mutant tissues. We discuss a role for HST as a hitherto unrecognized regulator of miRNA movement in relation to its recently assigned nuclear function at the nexus of MIRNA transcription and miRNA processing.
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Affiliation(s)
| | - Florence Jay
- Department of BiologyETH ZürichZürichSwitzerland
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33
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Kondhare KR, Patil NS, Banerjee AK. A historical overview of long-distance signalling in plants. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4218-4236. [PMID: 33682884 DOI: 10.1093/jxb/erab048] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Be it a small herb or a large tree, intra- and intercellular communication and long-distance signalling between distant organs are crucial for every aspect of plant development. The vascular system, comprising xylem and phloem, acts as a major conduit for the transmission of long-distance signals in plants. In addition to expanding our knowledge of vascular development, numerous reports in the past two decades revealed that selective populations of RNAs, proteins, and phytohormones function as mobile signals. Many of these signals were shown to regulate diverse physiological processes, such as flowering, leaf and root development, nutrient acquisition, crop yield, and biotic/abiotic stress responses. In this review, we summarize the significant discoveries made in the past 25 years, with emphasis on key mobile signalling molecules (mRNAs, proteins including RNA-binding proteins, and small RNAs) that have revolutionized our understanding of how plants integrate various intrinsic and external cues in orchestrating growth and development. Additionally, we provide detailed insights on the emerging molecular mechanisms that might control the selective trafficking and delivery of phloem-mobile RNAs to target tissues. We also highlight the cross-kingdom movement of mobile signals during plant-parasite relationships. Considering the dynamic functions of these signals, their implications in crop improvement are also discussed.
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Affiliation(s)
- Kirtikumar R Kondhare
- Plant Molecular Biology Unit, Biochemical Sciences Division, CSIR-National Chemical Laboratory (NCL) Pune, Maharashtra, India
| | - Nikita S Patil
- Biology Division, Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Anjan K Banerjee
- Biology Division, Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
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34
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Ma X, Denyer T, Javelle M, Feller A, Timmermans MCP. Genome-wide analysis of plant miRNA action clarifies levels of regulatory dynamics across developmental contexts. Genome Res 2021; 31:811-822. [PMID: 33863807 PMCID: PMC8092011 DOI: 10.1101/gr.270918.120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 03/04/2021] [Indexed: 01/12/2023]
Abstract
Development of complex organisms requires the delicate and dynamic spatiotemporal regulation of gene expression. Central to this are microRNAs (miRNAs). These mobile small RNAs offer specificity in conveying positional information and versatility in patterning the outcomes of gene expression. However, the parameters that shape miRNA output during development are still to be clarified. Here, we address this question on a genome-wide scale, using the maize shoot apex as a model. We show that patterns and levels of miRNA accumulation are largely determined at the transcriptional level, but are finessed post-transcriptionally in a tissue-dependent manner. The stem cell environments of the shoot apical meristem and vasculature appear particularly liable to this. Tissue-specific effects are also apparent at the level of target repression, with target cleavage products in the vasculature exceeding those of other tissues. Our results argue against a clearance mode of regulation purely at the level of transcript cleavage, leading us to propose that transcript cleavage provides a baseline level of target repression, onto which miRNA-driven translational repression can act to toggle the mode of target regulation between clearance and rheostat. Our data show how the inherent complexities of miRNA pathways allow the accumulation and activity of these small RNAs to be tailored in space and time to bring about the gene expression versatility needed during development.
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Affiliation(s)
- Xiaoli Ma
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
| | - Tom Denyer
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
| | | | - Antje Feller
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
| | - Marja C P Timmermans
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
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35
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Geng Y, Guo L, Han H, Liu X, Banks JA, Wisecaver JH, Zhou Y. Conservation and diversification of HAIRY MERISTEM gene family in land plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:366-378. [PMID: 33484592 DOI: 10.1111/tpj.15169] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/07/2021] [Accepted: 01/18/2021] [Indexed: 05/27/2023]
Abstract
The shoot apical meristems (SAMs) of land plants are crucial for plant growth and organ formation. In several angiosperms, the HAIRY MERISTEM (HAM) genes function as key regulators that control meristem development and stem cell homeostasis. To date, the origin and evolutionary history of the HAM family in land plants remains unclear. Potentially shared and divergent functions of HAM family members from angiosperms and non-angiosperms are also not known. In constructing a comprehensive phylogeny of the HAM family, we show that HAM proteins are widely present in land plants and that HAM proteins originated prior to the divergence of bryophytes. The HAM family was duplicated in a common ancestor of angiosperms, leading to two distinct groups: type I and type II. Type-II HAM members are widely present in angiosperms, whereas type-I HAM members were independently lost in different orders of monocots. Furthermore, HAM members from angiosperms and non-angiosperms (including bryophytes, lycophytes, ferns and gymnosperms) are able to replace the role of the type-II HAM genes in Arabidopsis, maintaining established SAMs and promoting the initiation of new stem cell niches. Our results uncover the conserved functions of HAM family members and reveal the conserved regulatory mechanisms underlying HAM expression patterning in meristems, providing insight into the evolution of key stem cell regulators in land plants.
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Affiliation(s)
- Yuan Geng
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Lei Guo
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Han Han
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Xing Liu
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Jo Ann Banks
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Jennifer H Wisecaver
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
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36
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Iida H, Takada S. A Quarter Century History of ATML1 Gene Research. PLANTS 2021; 10:plants10020290. [PMID: 33546382 PMCID: PMC7913478 DOI: 10.3390/plants10020290] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 11/16/2022]
Abstract
The cloning of the ATML1 gene, encoding an HD-ZIP class IV transcription factor, was first reported in 1996. Because ATML1 mRNA was preferentially detected in the shoot epidermis, cis-regulatory sequences of ATML1 have been used to drive gene expression in the outermost cells of the shoot apical meristem and leaves, even before the function of ATML1 was understood. Later studies revealed that ATML1 is required for developmental processes related to shoot epidermal specification and differentiation. Consistent with its central role in epidermal development, ATML1 activity has been revealed to be restricted to the outermost cells via several regulatory mechanisms. In this review, we look back on the history of ATML1 research and provide a perspective for future studies.
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Affiliation(s)
- Hiroyuki Iida
- Institute of Biotechnology, HiLIFE, University of Helsinki, Viikinkaari 1, 00014 Helsinki, Finland;
| | - Shinobu Takada
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1–1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
- Correspondence:
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37
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Geng Y, Zhou Y. HAM Gene Family and Shoot Meristem Development. FRONTIERS IN PLANT SCIENCE 2021; 12:800332. [PMID: 34987539 PMCID: PMC8720772 DOI: 10.3389/fpls.2021.800332] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 11/19/2021] [Indexed: 05/18/2023]
Abstract
Land plants develop highly diversified shoot architectures, all of which are derived from the pluripotent stem cells in shoot apical meristems (SAMs). As sustainable resources for continuous organ formation in the aboveground tissues, SAMs play an important role in determining plant yield and biomass production. In this review, we summarize recent advances in understanding one group of key regulators - the HAIRY MERISTEM (HAM) family GRAS domain proteins - in shoot meristems. We highlight the functions of HAM family members in dictating shoot stem cell initiation and proliferation, the signaling cascade that shapes HAM expression domains in shoot meristems, and the conservation and diversification of HAM family members in land plants. We also discuss future directions that potentially lead to a more comprehensive view of the HAM gene family and stem cell homeostasis in land plants.
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Affiliation(s)
- Yuan Geng
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- *Correspondence: Yun Zhou,
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38
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Mallet J, Laufs P, Leduc N, Le Gourrierec J. Photocontrol of Axillary Bud Outgrowth by MicroRNAs: Current State-of-the-Art and Novel Perspectives Gained From the Rosebush Model. FRONTIERS IN PLANT SCIENCE 2021; 12:770363. [PMID: 35173747 PMCID: PMC8841825 DOI: 10.3389/fpls.2021.770363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/13/2021] [Indexed: 05/05/2023]
Abstract
Shoot branching is highly dependent on environmental factors. While many species show some light dependence for branching, the rosebush shows a strict requirement for light to allow branching, making this species an excellent model to further understand how light impinges on branching. Here, in the first part, we provide a review of the current understanding of how light may modulate the complex regulatory network of endogenous factors like hormones (SL, IAA, CK, GA, and ABA), nutrients (sugar and nitrogen), and ROS to control branching. We review the regulatory contribution of microRNAs (miRNAs) to branching in different species, highlighting the action of such evolutionarily conserved factors. We underline some possible pathways by which light may modulate miRNA-dependent regulation of branching. In the second part, we exploit the strict light dependence of rosebush for branching to identify putative miRNAs that could contribute to the photocontrol of branching. For this, we first performed a profiling of the miRNAs expressed in early light-induced rosebush buds and next tested whether they were predicted to target recognized regulators of branching. Thus, we identified seven miRNAs (miR156, miR159, miR164, miR166, miR399, miR477, and miR8175) that could target nine genes (CKX1/6, EXPA3, MAX4, CYCD3;1, SUSY, 6PFK, APX1, and RBOHB1). Because these genes are affecting branching through different hormonal or metabolic pathways and because expression of some of these genes is photoregulated, our bioinformatic analysis suggests that miRNAs may trigger a rearrangement of the regulatory network to modulate branching in response to light environment.
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Affiliation(s)
- Julie Mallet
- University of Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers, France
| | - Patrick Laufs
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Nathalie Leduc
- University of Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers, France
| | - José Le Gourrierec
- University of Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers, France
- *Correspondence: José Le Gourrierec,
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39
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Zhou L, Du F, Feng S, Hu J, Lü S, Long M, Jiao Y. Epidermal restriction confers robustness to organ shapes. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:1853-1867. [PMID: 32725947 DOI: 10.1111/jipb.12998] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
The shape of comparable tissues and organs is consistent among individuals of a given species, but how this consistency or robustness is achieved remains an open question. The interaction between morphogenetic factors determines organ formation and subsequent shaping, which is ultimately a mechanical process. Using a computational approach, we show that the epidermal layer is essential for the robustness of organ geometry control. Specifically, proper epidermal restriction allows organ asymmetry maintenance, and the tensile epidermal layer is sufficient to suppress local variability in growth, leading to shape robustness. The model explains the enhanced organ shape variations in epidermal mutant plants. In addition, differences in the patterns of epidermal restriction may underlie the initial establishment of organ asymmetry. Our results show that epidermal restriction can answer the longstanding question of how cellular growth noise is averaged to produce precise organ shapes, and the findings also shed light on organ asymmetry establishment.
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Affiliation(s)
- Lüwen Zhou
- Smart Materials and Advanced Structure Laboratory, School of Mechanical Engineering and Mechanics, Ningbo University, Ningbo, 315211, China
| | - Fei Du
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shiliang Feng
- Smart Materials and Advanced Structure Laboratory, School of Mechanical Engineering and Mechanics, Ningbo University, Ningbo, 315211, 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
- University of Chinese Academy of Sciences, Beijing, 100049, 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
- 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
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuling Jiao
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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40
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Fouracre JP, Poethig RS. Lonely at the top? Regulation of shoot apical meristem activity by intrinsic and extrinsic factors. CURRENT OPINION IN PLANT BIOLOGY 2020; 58:17-24. [PMID: 33099210 PMCID: PMC7752823 DOI: 10.1016/j.pbi.2020.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/22/2020] [Accepted: 08/28/2020] [Indexed: 05/22/2023]
Abstract
All the above-ground organs of a plant are derived from stem cells that reside in shoot apical meristems (SAM). Over the past 25 years, the genetic pathways that control the proliferation of stem cells within the SAM, and the differentiation of their progenitors into lateral organs, have been described in great detail. However, longstanding questions regarding the importance of communication between cells within the SAM and lateral organs have, until recently, remained unanswered. In this review, we describe recent investigations into the extent, nature and significance of signaling both to and from the SAM.
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Affiliation(s)
- Jim P Fouracre
- Biology Department, University of Pennsylvania, 433 S. University Ave, Philadelphia, PA, 19104, USA
| | - Richard Scott Poethig
- Biology Department, University of Pennsylvania, 433 S. University Ave, Philadelphia, PA, 19104, USA.
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41
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Liu Z, Shpak ED, Hong T. A mathematical model for understanding synergistic regulations and paradoxical feedbacks in the shoot apical meristem. Comput Struct Biotechnol J 2020; 18:3877-3889. [PMID: 33335685 PMCID: PMC7720093 DOI: 10.1016/j.csbj.2020.11.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 01/22/2023] Open
Abstract
The shoot apical meristem (SAM) is the primary stem cell niche in plant shoots. Stem cells in the SAM are controlled by an intricate regulatory network, including negative feedback between WUSCHEL (WUS) and CLAVATA3 (CLV3). Recently, we identified a group of signals, Epidermal Patterning Factor-Like (EPFL) proteins, that are produced at the peripheral region and are important for SAM homeostasis. Here, we present a mathematical model for the SAM regulatory network. The model revealed that the SAM uses EPFL and signals such as HAIRY MERISTEM from the middle in a synergistic manner to constrain both WUS and CLV3. We found that interconnected negative and positive feedbacks between WUS and CLV3 ensure stable WUS expression in the SAM when facing perturbations, and the positive feedback loop also maintains distinct cell populations containing WUS on and CLV3 on cells in the apical-basal direction. Furthermore, systematic perturbations of the parameters revealed a tradeoff between optimizations of multiple patterning features. Our results provide a holistic view of the regulation of SAM patterning in multiple dimensions. They give insights into how Arabidopsis integrates signals from lateral and apical-basal axes to control the SAM patterning, and they shed light into design principles that may be widely useful for understanding regulatory networks of stem cell niche.
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Affiliation(s)
- Ziyi Liu
- Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN, United States
| | - Elena D. Shpak
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, United States
| | - Tian Hong
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, United States
- National Institute for Mathematical and Biological Synthesis, Knoxville, TN, United States
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42
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Gundu S, Tabassum N, Blilou I. Moving with purpose and direction: transcription factor movement and cell fate determination revisited. CURRENT OPINION IN PLANT BIOLOGY 2020; 57:124-132. [PMID: 32992134 DOI: 10.1016/j.pbi.2020.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/13/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Cell diversity in a multicellular organism relies on cell-cell communication where cells must receive positional information as input signals to adopt their proper cell fate in the right place and at the right time. This process is achieved through triggering signaling cascades that drive cellular changes during development. In plants, signaling through mobile transcription factors (TF) plays a central role in development. Rather than acting cell-autonomously and exclusive to their expression domains, many TFs move between cells and deploy regulatory networks and cell type-specific effectors to achieve their biological functions. Here, we highlight a few examples of mobile TFs central to cell fate specification in Arabidopsis.
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Affiliation(s)
- Shyam Gundu
- Laboratory of Plant Cell and Developmental Biology, King Abdullah University of Science and Technology (KAUST), Biological and Environmental Sciences and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia
| | - Naheed Tabassum
- Laboratory of Plant Cell and Developmental Biology, King Abdullah University of Science and Technology (KAUST), Biological and Environmental Sciences and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia
| | - Ikram Blilou
- Laboratory of Plant Cell and Developmental Biology, King Abdullah University of Science and Technology (KAUST), Biological and Environmental Sciences and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia.
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43
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Fletcher JC. Recent Advances in Arabidopsis CLE Peptide Signaling. TRENDS IN PLANT SCIENCE 2020; 25:1005-1016. [PMID: 32402660 DOI: 10.1016/j.tplants.2020.04.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 05/18/2023]
Abstract
Like communities of people, communities of cells must continuously communicate to thrive. Polypeptide signaling molecules that act as mobile ligands are widely used by eukaryotic organisms to transmit information between cells to coordinate developmental processes and responses to environmental cues. In plants, the CLAVATA3/EMBRYO SURROUNDING REGION-RELATED (CLE) genes encode a large family of extracellular signaling peptides that stimulate receptor-mediated signal transduction cascades to modulate diverse developmental and physiological processes. This review highlights the emerging roles of Arabidopsisthaliana CLE peptide signaling pathways in shoot stem cell homeostasis and root xylem development, as well as in root protophloem cell differentiation, vascular cambium activity, and stomatal formation and closure.
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Affiliation(s)
- Jennifer C Fletcher
- Plant Gene Expression Center, US Department of Agriculture (USDA) Agricultural Research Service, Albany, CA 94710, USA; Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
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Maizel A, Markmann K, Timmermans M, Wachter A. To move or not to move: roles and specificity of plant RNA mobility. CURRENT OPINION IN PLANT BIOLOGY 2020; 57:52-60. [PMID: 32634685 DOI: 10.1016/j.pbi.2020.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/07/2020] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
Intercellular communication in plants coordinates cellular functions during growth and development, and in response to environmental cues. RNAs figure prominently among the mobile signaling molecules used. Many hundreds of RNA species move over short and long distances, and can be mutually exchanged in biotic interactions. Understanding the specificity determinants of RNA mobility and the physiological relevance of this phenomenon are areas of active research. Here, we highlight the recent progress in our knowledge of small RNA and messenger RNA movement. Particular emphasis is given to novel insight into the specificity determinants of messenger RNA mobility, the role of small RNA movement in development, and the specificity of RNA exchange in plant-plant and plant-microbe interactions.
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Affiliation(s)
- Alexis Maizel
- Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Katharina Markmann
- Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - Marja Timmermans
- Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
| | - Andreas Wachter
- Institute for Molecular Physiology (imP), University of Mainz, Johannes von Müller-Weg 6, 55128 Mainz, Germany
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45
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Han H, Geng Y, Guo L, Yan A, Meyerowitz EM, Liu X, Zhou Y. The Overlapping and Distinct Roles of HAM Family Genes in Arabidopsis Shoot Meristems. FRONTIERS IN PLANT SCIENCE 2020; 11:541968. [PMID: 33013964 PMCID: PMC7498855 DOI: 10.3389/fpls.2020.541968] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 08/19/2020] [Indexed: 05/02/2023]
Abstract
In Arabidopsis shoot apical meristems (SAMs), a well-characterized regulatory loop between WUSCHEL (WUS) and CLAVATA3 (CLV3) maintains stem cell homeostasis by regulating the balance between cell proliferation and cell differentiation. WUS proteins, translated in deep cell layers, move into the overlaying stem cells to activate CLV3. The secreted peptide CLV3 then regulates WUS levels through a ligand-receptor mediated signaling cascade. CLV3 is specifically expressed in the stem cells and repressed in the deep cell layers despite presence of the WUS activator, forming an apical-basal polarity along the axis of the SAM. Previously, we proposed and validated a hypothesis that the HAIRY MERISTEM (HAM) family genes regulate this polarity, keeping the expression of CLV3 off in interior cells of the SAM. However, the specific role of each individual member of the HAM family in this process remains to be elucidated. Combining live imaging and molecular genetics, we have dissected the conserved and distinct functions of different HAM family members in control of CLV3 patterning in the SAMs and in the de novo shoot stem cell niches as well.
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Affiliation(s)
- Han Han
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Yuan Geng
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Lei Guo
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - An Yan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, United States
| | - Elliot M. Meyerowitz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, United States
| | - Xing Liu
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- *Correspondence: Yun Zhou,
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