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Pérez-Sancho J, Van den Broeck L, García-Caparros P, Sozzani R. Insights into multilevel spatial regulation within the root stem cell niche. Curr Opin Genet Dev 2024; 86:102200. [PMID: 38704928 DOI: 10.1016/j.gde.2024.102200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 05/07/2024]
Abstract
All differentiated root cells derive from stem cells spatially organized within the stem cell niche (SCN), a microenvironment located within the root tip. Here, we compiled recent advances in the understanding of how the SCN drives the establishment and maintenance of cell types. The quiescent center (QC) is widely recognized as the primary driver of cell fate determination, but it is recently considered a convergence center of multiple signals. Cell identity of the cortex endodermis initials is mainly driven by the regulatory feedback loops between transcription factors (TFs), acting as mobile signals between neighboring cells, including the QC. As exemplified in the vascular initials, the precise spatial expression of these regulatory TFs is connected with a dynamic hormonal interplay. Thus, stem cell maintenance and cell differentiation are regulated by a plethora of signals forming a complex, multilevel regulatory network. Integrating the transcriptional and post-translational regulations, protein-protein interactions, and mobile signals into models will be fundamental for the comprehensive understanding of SCN maintenance and differentiation.
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Affiliation(s)
| | - Lisa Van den Broeck
- Plant and Microbial Biology Department and NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27695, USA. https://twitter.com/@LisaVandenBroec
| | | | - Rosangela Sozzani
- Plant and Microbial Biology Department and NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27695, USA.
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2
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Yang Y, Liu C, Yu Y, Ran G, Zhai N, Pi L. WUSCHEL RELATED HOMEOBOX5 and 7 maintain callus development by promoting cell division in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 346:112133. [PMID: 38795752 DOI: 10.1016/j.plantsci.2024.112133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 04/18/2024] [Accepted: 05/20/2024] [Indexed: 05/28/2024]
Abstract
In tissue culture, a high concentration of auxin in the callus induction medium (CIM) stimulates cell division and subsequent callus formation, which acquires root primordium-like characteristics necessary for cell pluripotency. In Arabidopsis, WUSCHEL-RELATED HOMEOBOX5 (WOX5) and its closest homolog WOX7, which are abundant in the middle cell layer of mature callus, play a crucial role in maintaining pluripotency by promoting auxin accumulation and enhancing cytokinin sensitivity. However, the mechanism by which WOX5/7 regulate callus formation remains unclear. In this study, we found that mutations in WOX5/7 resulted in a significant down-regulation of genes involved in the G2M and S phases during callus induction. Loss-of-function mutants of WOX5/7 exhibited reduced callus formation, which was correlated with decreased expression of CYCB1;1 compared to the wild-type. Furthermore, we provided evidence that WOX5 physically interacts with PHYTOCHROME A SIGNAL TRANSDUCTION1 (PAT1), which spatio-temporally co-expresses with WOX5 in early-induced callus, and up-regulates a subset of cycle-regulating genes targeted by PAT1. Collectively, our findings suggest a critical role for the WOX5-PAT1 protein complex in regulating cell cycle progression, thereby promoting the continuous growth capacity of pluripotent callus.
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Affiliation(s)
- Yi Yang
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Caifeng Liu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Yue Yu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Guiping Ran
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Ning Zhai
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
| | - Limin Pi
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China.
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3
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Han E, Geng Z, Qin Y, Wang Y, Ma S. Single-cell network analysis reveals gene expression programs for Arabidopsis root development and metabolism. PLANT COMMUNICATIONS 2024:100978. [PMID: 38783601 DOI: 10.1016/j.xplc.2024.100978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/24/2024] [Accepted: 05/20/2024] [Indexed: 05/25/2024]
Abstract
Single-cell RNA-sequencing datasets of Arabidopsis roots have been generated, but related comprehensive gene co-expression network analyses are lacking. We conducted a single-cell gene co-expression network analysis with publicly available scRNA-seq datasets of Arabidopsis roots using a SingleCellGGM algorithm. The analysis identified 149 gene co-expression modules, which we considered to be gene expression programs (GEPs). By examining their spatiotemporal expression, we identified GEPs specifically expressed in major root cell types along their developmental trajectories. These GEPs define gene programs regulating root cell development at different stages and are enriched with relevant developmental regulators. As examples, a GEP specific for the quiescent center (QC) contains 20 genes regulating QC and stem cell niche homeostasis, and four GEPs are expressed in sieve elements (SEs) from early to late developmental stages, with the early-stage GEP containing 17 known SE developmental regulators. We also identified GEPs for metabolic pathways with cell-type-specific expression, suggesting the existence of cell-type-specific metabolism in roots. Using the GEPs, we discovered and verified a columella-specific gene, NRL27, as a regulator of the auxin-related root gravitropism response. Our analysis thus systematically reveals GEPs that regulate Arabidopsis root development and metabolism and provides ample resources for root biology studies.
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Affiliation(s)
- Ershang Han
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Innovation Academy for Seed Design, Chinese Academy of Sciences, Hefei 230027, China
| | - Zhenxing Geng
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Innovation Academy for Seed Design, Chinese Academy of Sciences, Hefei 230027, China
| | - Yue Qin
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Innovation Academy for Seed Design, Chinese Academy of Sciences, Hefei 230027, China
| | - Yuewei Wang
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Innovation Academy for Seed Design, Chinese Academy of Sciences, Hefei 230027, China
| | - Shisong Ma
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Innovation Academy for Seed Design, Chinese Academy of Sciences, Hefei 230027, China; School of Data Science, University of Science and Technology of China, Hefei 230027, China.
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4
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Smet W, Blilou I. A blast from the past: Understanding stem cell specification in plant roots using laser ablation. QUANTITATIVE PLANT BIOLOGY 2023; 4:e14. [PMID: 38034417 PMCID: PMC10685261 DOI: 10.1017/qpb.2023.13] [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: 02/02/2023] [Revised: 09/15/2023] [Accepted: 10/10/2023] [Indexed: 12/02/2023]
Abstract
In the Arabidopsis root, growth is sustained by the meristem. Signalling from organiser cells, also termed the quiescent centre (QC), is essential for the maintenance and replenishment of the stem cells. Here, we highlight three publications from the founder of the concept of the stem cell niche in Arabidopsis and a pioneer in unravelling regulatory modules governing stem cell specification and maintenance, as well as tissue patterning in the root meristem: Ben Scheres. His research has tremendously impacted the plant field. We have selected three publications from the Scheres legacy, which can be considered a breakthrough in the field of plant developmental biology. van den Berg et al. (1995) and van den Berg et al. (1997) uncovered that positional information-directed patterning. Sabatini et al. (1999), discovered that auxin maxima determine tissue patterning and polarity. We describe how simple but elegant experimental designs have provided the foundation of our current understanding of the functioning of the root meristem.
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Affiliation(s)
- Wouter Smet
- Biological and Environmental Science and Engineering (BESE) Division, Plant Cell and Developmental Biology, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Ikram Blilou
- Biological and Environmental Science and Engineering (BESE) Division, Plant Cell and Developmental Biology, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
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5
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Nolan TM, Vukašinović N, Hsu CW, Zhang J, Vanhoutte I, Shahan R, Taylor IW, Greenstreet L, Heitz M, Afanassiev A, Wang P, Szekely P, Brosnan A, Yin Y, Schiebinger G, Ohler U, Russinova E, Benfey PN. Brassinosteroid gene regulatory networks at cellular resolution in the Arabidopsis root. Science 2023; 379:eadf4721. [PMID: 36996230 PMCID: PMC10119888 DOI: 10.1126/science.adf4721] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 02/09/2023] [Indexed: 04/01/2023]
Abstract
Brassinosteroids are plant steroid hormones that regulate diverse processes, such as cell division and cell elongation, through gene regulatory networks that vary in space and time. By using time series single-cell RNA sequencing to profile brassinosteroid-responsive gene expression specific to different cell types and developmental stages of the Arabidopsis root, we identified the elongating cortex as a site where brassinosteroids trigger a shift from proliferation to elongation associated with increased expression of cell wall-related genes. Our analysis revealed HOMEOBOX FROM ARABIDOPSIS THALIANA 7 (HAT7) and GT-2-LIKE 1 (GTL1) as brassinosteroid-responsive transcription factors that regulate cortex cell elongation. These results establish the cortex as a site of brassinosteroid-mediated growth and unveil a brassinosteroid signaling network regulating the transition from proliferation to elongation, which illuminates aspects of spatiotemporal hormone responses.
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Affiliation(s)
| | - Nemanja Vukašinović
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Che-Wei Hsu
- Department of Biology, Duke University, Durham, NC, USA
- Department of Biology, Humboldt Universitat zu Berlin, Berlin, Germany
- The Berlin Institute for Medical Systems Biology, Max Delbruck Center for Molecular Medicine, Berlin, Germany
| | | | - Isabelle Vanhoutte
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Rachel Shahan
- Department of Biology, Duke University, Durham, NC, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA
| | | | - Laura Greenstreet
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Matthieu Heitz
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Anton Afanassiev
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Ping Wang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, USA
| | - Pablo Szekely
- Department of Biology, Duke University, Durham, NC, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA
| | - Aiden Brosnan
- Department of Biology, Duke University, Durham, NC, USA
| | - Yanhai Yin
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, USA
| | - Geoffrey Schiebinger
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada
| | - Uwe Ohler
- Department of Biology, Humboldt Universitat zu Berlin, Berlin, Germany
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, USA
- Department of Computer Science, Humboldt Universitat zu Berlin, Berlin, Germany
| | - Eugenia Russinova
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Philip N Benfey
- Department of Biology, Duke University, Durham, NC, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA
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6
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García-Gómez ML, Reyes-Hernández BJ, Sahoo DP, Napsucialy-Mendivil S, Quintana-Armas AX, Pedroza-García JA, Shishkova S, Torres-Martínez HH, Pacheco-Escobedo MA, Dubrovsky JG. A mutation in THREONINE SYNTHASE 1 uncouples proliferation and transition domains of the root apical meristem: experimental evidence and in silico proposed mechanism. Development 2022; 149:278438. [PMID: 36278862 PMCID: PMC9796171 DOI: 10.1242/dev.200899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022]
Abstract
A continuum from stem to transit-amplifying to a differentiated cell state is a common theme in multicellular organisms. In the plant root apical meristem (RAM), transit-amplifying cells are organized into two domains: cells from the proliferation domain (PD) are displaced to the transition domain (TD), suggesting that both domains are necessarily coupled. Here, we show that in the Arabidopsis thaliana mto2-2 mutant, in which threonine (Thr) synthesis is affected, the RAM lacks the PD. Through a combination of cell length profile analysis, mathematical modeling and molecular markers, we establish that the PD and TD can be uncoupled. Remarkably, although the RAM of mto2-2 is represented solely by the TD, the known factors of RAM maintenance and auxin signaling are expressed in the mutant. Mathematical modeling predicts that the stem cell niche depends on Thr metabolism and that, when disturbed, the normal continuum of cell states becomes aborted.
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Affiliation(s)
- Monica L. García-Gómez
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - Blanca J. Reyes-Hernández
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - Debee P. Sahoo
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - Selene Napsucialy-Mendivil
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - Aranza X. Quintana-Armas
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - José A. Pedroza-García
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - Svetlana Shishkova
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - Héctor H. Torres-Martínez
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico
| | - Mario A. Pacheco-Escobedo
- Facultad de Ciencias de la Salud, Universidad Tecnológica de México – UNITEC MÉXICO – Campus Atizapán, Av. Calacoaya 7, Atizapán de Zaragoza, Estado de México, 52970, Mexico
| | - Joseph G. Dubrovsky
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico,Author for correspondence ()
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7
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Ferrari C, Manosalva Pérez N, Vandepoele K. MINI-EX: Integrative inference of single-cell gene regulatory networks in plants. MOLECULAR PLANT 2022; 15:1807-1824. [PMID: 36307979 DOI: 10.1016/j.molp.2022.10.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/30/2022] [Accepted: 10/21/2022] [Indexed: 05/26/2023]
Abstract
Multicellular organisms, such as plants, are characterized by highly specialized and tightly regulated cell populations, establishing specific morphological structures and executing distinct functions. Gene regulatory networks (GRNs) describe condition-specific interactions of transcription factors (TFs) regulating the expression of target genes, underpinning these specific functions. As efficient and validated methods to identify cell-type-specific GRNs from single-cell data in plants are lacking, limiting our understanding of the organization of specific cell types in both model species and crops, we developed MINI-EX (Motif-Informed Network Inference based on single-cell EXpression data), an integrative approach to infer cell-type-specific networks in plants. MINI-EX uses single-cell transcriptomic data to define expression-based networks and integrates TF motif information to filter the inferred regulons, resulting in networks with increased accuracy. Next, regulons are assigned to different cell types, leveraging cell-specific expression, and candidate regulators are prioritized using network centrality measures, functional annotations, and expression specificity. This embedded prioritization strategy offers a unique and efficient means to unravel signaling cascades in specific cell types controlling a biological process of interest. We demonstrate the stability of MINI-EX toward input data sets with low number of cells and its robustness toward missing data, and show that it infers state-of-the-art networks with a better performance compared with other related single-cell network tools. MINI-EX successfully identifies key regulators controlling root development in Arabidopsis and rice, leaf development in Arabidopsis, and ear development in maize, enhancing our understanding of cell-type-specific regulation and unraveling the roles of different regulators controlling the development of specific cell types in plants.
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Affiliation(s)
- Camilla Ferrari
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Nicolás Manosalva Pérez
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Klaas Vandepoele
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium; Bioinformatics Institute Ghent, Ghent University, 9052 Ghent, Belgium.
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8
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Chen Z, Wu Z, Dong W, Liu S, Tian L, Li J, Du H. MYB Transcription Factors Becoming Mainstream in Plant Roots. Int J Mol Sci 2022; 23:ijms23169262. [PMID: 36012533 PMCID: PMC9409031 DOI: 10.3390/ijms23169262] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/12/2022] [Accepted: 08/16/2022] [Indexed: 11/26/2022] Open
Abstract
The function of the root system is crucial for plant survival, such as anchoring plants, absorbing nutrients and water from the soil, and adapting to stress. MYB transcription factors constitute one of the largest transcription factor families in plant genomes with structural and functional diversifications. Members of this superfamily in plant development and cell differentiation, specialized metabolism, and biotic and abiotic stress processes are widely recognized, but their roles in plant roots are still not well characterized. Recent advances in functional studies remind us that MYB genes may have potentially key roles in roots. In this review, the current knowledge about the functions of MYB genes in roots was summarized, including promoting cell differentiation, regulating cell division through cell cycle, response to biotic and abiotic stresses (e.g., drought, salt stress, nutrient stress, light, gravity, and fungi), and mediate phytohormone signals. MYB genes from the same subfamily tend to regulate similar biological processes in roots in redundant but precise ways. Given their increasing known functions and wide expression profiles in roots, MYB genes are proposed as key components of the gene regulatory networks associated with distinct biological processes in roots. Further functional studies of MYB genes will provide an important basis for root regulatory mechanisms, enabling a more inclusive green revolution and sustainable agriculture to face the constant changes in climate and environmental conditions.
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Affiliation(s)
- Zhuo Chen
- College of Agronomy and Biotechnology, Chongqing Engineering Research Center for Rapeseed, Southwest University, Chongqing 400716, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Zexuan Wu
- College of Agronomy and Biotechnology, Chongqing Engineering Research Center for Rapeseed, Southwest University, Chongqing 400716, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Wenyu Dong
- College of Agronomy and Biotechnology, Chongqing Engineering Research Center for Rapeseed, Southwest University, Chongqing 400716, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Shiying Liu
- College of Agronomy and Biotechnology, Chongqing Engineering Research Center for Rapeseed, Southwest University, Chongqing 400716, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Lulu Tian
- College of Agronomy and Biotechnology, Chongqing Engineering Research Center for Rapeseed, Southwest University, Chongqing 400716, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Jiana Li
- College of Agronomy and Biotechnology, Chongqing Engineering Research Center for Rapeseed, Southwest University, Chongqing 400716, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Hai Du
- College of Agronomy and Biotechnology, Chongqing Engineering Research Center for Rapeseed, Southwest University, Chongqing 400716, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
- Correspondence: ; Tel.: +86-182-2348-0008
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9
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Mercadal J, Betegón-Putze I, Bosch N, Caño-Delgado AI, Ibañes M. BRAVO self-confined expression through WOX5 in the Arabidopsis root stem-cell niche. Development 2022; 149:dev200510. [PMID: 35899779 PMCID: PMC9440757 DOI: 10.1242/dev.200510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 06/23/2022] [Indexed: 12/02/2023]
Abstract
In animals and plants, stem-cell niches are local microenvironments that are tightly regulated to preserve their unique identity while communicating with adjacent cells that will give rise to specialized cell types. In the primary root of Arabidopsis thaliana, two transcription factors, BRAVO and WOX5, among others, are expressed in the stem-cell niche. Intriguingly, BRAVO, a repressor of quiescent center divisions, confines its own gene expression to the stem-cell niche, as evidenced in a bravo mutant background. Here, we propose through mathematical modeling that BRAVO confines its own expression domain to the stem-cell niche by attenuating a WOX5-dependent diffusible activator of BRAVO. This negative feedback drives WOX5 activity to be spatially restricted as well. The results show that WOX5 diffusion and sequestration by binding to BRAVO are sufficient to drive the experimentally observed confined BRAVO expression at the stem-cell niche. We propose that the attenuation of a diffusible activator can be a general mechanism acting at other stem-cell niches to spatially confine genetic activity to a small region while maintaining signaling within them and with the surrounding cells.
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Affiliation(s)
- Josep Mercadal
- Departament de Física de la Matèria Condensada, Facultat de Física, Universitat de Barcelona, 08028 Barcelona, Spain
- Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain
| | - Isabel Betegón-Putze
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB (Cerdanyola del Vallès), 08193 Barcelona, Spain
| | - Nadja Bosch
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB (Cerdanyola del Vallès), 08193 Barcelona, Spain
| | - Ana I. Caño-Delgado
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB (Cerdanyola del Vallès), 08193 Barcelona, Spain
| | - Marta Ibañes
- Departament de Física de la Matèria Condensada, Facultat de Física, Universitat de Barcelona, 08028 Barcelona, Spain
- Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain
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10
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Gutierrez C. A Journey to the Core of the Plant Cell Cycle. Int J Mol Sci 2022; 23:8154. [PMID: 35897730 PMCID: PMC9330084 DOI: 10.3390/ijms23158154] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/16/2022] [Accepted: 07/21/2022] [Indexed: 02/04/2023] Open
Abstract
Production of new cells as a result of progression through the cell division cycle is a fundamental biological process for the perpetuation of both unicellular and multicellular organisms. In the case of plants, their developmental strategies and their largely sessile nature has imposed a series of evolutionary trends. Studies of the plant cell division cycle began with cytological and physiological approaches in the 1950s and 1960s. The decade of 1990 marked a turn point with the increasing development of novel cellular and molecular protocols combined with advances in genetics and, later, genomics, leading to an exponential growth of the field. In this article, I review the current status of plant cell cycle studies but also discuss early studies and the relevance of a multidisciplinary background as a source of innovative questions and answers. In addition to advances in a deeper understanding of the plant cell cycle machinery, current studies focus on the intimate interaction of cell cycle components with almost every aspect of plant biology.
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Affiliation(s)
- Crisanto Gutierrez
- Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, Nicolas Cabrera 1, Cantoblanco, 28049 Madrid, Spain
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11
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Strotmann VI, Stahl Y. Visualization of in vivo protein-protein interactions in plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3866-3880. [PMID: 35394544 PMCID: PMC9232200 DOI: 10.1093/jxb/erac139] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
Molecular processes depend on the concerted and dynamic interactions of proteins, either by one-on-one interactions of the same or different proteins or by the assembly of larger protein complexes consisting of many different proteins. Here, not only the protein-protein interaction (PPI) itself, but also the localization and activity of the protein of interest (POI) within the cell is essential. Therefore, in all cell biological experiments, preserving the spatio-temporal state of one POI relative to another is key to understanding the underlying complex and dynamic regulatory mechanisms in vivo. In this review, we examine some of the applicable techniques to measure PPIs in planta as well as recent combinatorial advances of PPI methods to measure the formation of higher order complexes with an emphasis on in vivo imaging techniques. We compare the different methods and discuss their benefits and potential pitfalls to facilitate the selection of appropriate techniques by providing a comprehensive overview of how to measure in vivo PPIs in plants.
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Affiliation(s)
- Vivien I Strotmann
- Institute for Developmental Genetics, Heinrich-Heine University, Universitätsstr. 1, D-40225 Düsseldorf, Germany
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Strotmann VI, Stahl Y. At the root of quiescence: function and regulation of the quiescent center. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:6716-6726. [PMID: 34111273 DOI: 10.1093/jxb/erab275] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/08/2021] [Indexed: 06/12/2023]
Abstract
The quiescent center (QC) of roots consists of a rarely dividing pool of stem cells within the root apical meristem (RAM). The QC maintains the surrounding more frequently dividing initials, together constituting the stem cell niche of the RAM. The initials, after several rounds of division and differentiation, give rise to nearly all tissues necessary for root function. Hence, QC establishment, maintenance, and function are key for producing the whole plant root system and are therefore at the foundation of plant growth and productivity. Although the concept of the QC has been known since the 1950s, much of its molecular regulations and their intricate interconnections, especially in more complex root systems such as cereal RAMs, remain elusive. In Arabidopsis, molecular factors such as phytohormones, small signaling peptides and their receptors, and key transcription factors play important roles in a complex and intertwined regulatory network. In cereals, homologs of these factors are present; however, QC maintenance in the larger RAMs of cereals might also require more complex control of QC cell regulation by a combination of asymmetric and symmetric divisions. Here, we summarize current knowledge on QC maintenance in Arabidopsis and compare it with that of agriculturally relevant cereal crops.
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Affiliation(s)
- Vivien I Strotmann
- Institute for Developmental Genetics, Heinrich-Heine University, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Yvonne Stahl
- Institute for Developmental Genetics, Heinrich-Heine University, Universitätsstr. 1, 40225 Düsseldorf, Germany
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