151
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Mira MM, Huang S, Kapoor K, Hammond C, Hill RD, Stasolla C. Expression of Arabidopsis class 1 phytoglobin (AtPgb1) delays death and degradation of the root apical meristem during severe PEG-induced water deficit. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5653-5668. [PMID: 29059380 PMCID: PMC5853930 DOI: 10.1093/jxb/erx371] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Maintenance of a functional root is fundamental to plant survival in response to some abiotic stresses, such as water deficit. In this study, we found that overexpression of Arabidopsis class 1 phytoglobin (AtPgb1) alleviated the growth retardation of polyethylene glycol (PEG)-induced water stress by reducing programmed cell death (PCD) associated with protein folding in the endoplasmic reticulum (ER). This was in contrast to PEG-stressed roots down-regulating AtPgb1 that exhibited extensive PCD and reduced expression of several attenuators of ER stress, including BAX Inhibitor-1 (BI-1). The death program experienced by the suppression of AtPgb1 in stressed roots was mediated by reactive oxygen species (ROS) and ethylene. Suppression of ROS synthesis or ethylene perception reduced PCD and partially restored root growth. The PEG-induced cessation of root growth was preceded by structural changes in the root apical meristem (RAM), including the loss of cell and tissue specification, possibly as a result of alterations in PIN1- and PIN4-mediated auxin accumulation at the root pole. These events were attenuated by the overexpression of AtPgb1 and aggravated when AtPgb1 was suppressed. Specifically, suppression of AtPgb1 compromised the functionality of the WOX5-expressing quiescent cells (QCs), leading to the early and premature differentiation of the adjacent columella stem cells and to a rapid reduction in meristem size. The expression and localization of other root domain markers, such as SCARECROW (SCR), which demarks the endodermis and QCs, and WEREWOLF (WER), which specifies the lateral root cap, were also most affected in PEG-treated roots with suppressed AtPgb1. Collectively, the results demonstrate that AtPgb1 exercises a protective role in roots exposed to lethal levels of PEG, and suggest a novel function of this gene in ensuring meristem functionality through the retention of cell fate specification.
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Affiliation(s)
- Mohamed M Mira
- Department of Botany, Faculty of Science, Tanta University, Tanta, Egypt
| | - Shuanglong Huang
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Karuna Kapoor
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Cassandra Hammond
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Robert D Hill
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
- Correspondence:
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152
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Tognetti VB, Bielach A, Hrtyan M. Redox regulation at the site of primary growth: auxin, cytokinin and ROS crosstalk. PLANT, CELL & ENVIRONMENT 2017; 40:2586-2605. [PMID: 28708264 DOI: 10.1111/pce.13021] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 06/17/2017] [Accepted: 06/24/2017] [Indexed: 05/18/2023]
Abstract
To maintain the activity of meristems is an absolute requirement for plant growth and development, and the role of the plant hormones auxin and cytokinin in apical meristem function is well established. Only little attention has been given, however, to the function of the reactive oxygen species (ROS) gradient along meristematic tissues and its interplay with hormonal regulatory networks. The interdependency between auxin-related, cytokinin-related and ROS-related circuits controls primary growth and development while modulating plant morphology in response to detrimental environmental factors. Because ROS interaction with redox-active compounds significantly affects the cellular redox gradient, the latter constitutes an interface for crosstalk between hormone and ROS signalling pathways. This review focuses on the mechanisms underlying ROS-dependent interactions with redox and hormonal components in shoot and root apical meristems which are crucial for meristems maintenance when plants are exposed to environmental hardships. We also emphasize the importance of cell type and the subcellular compartmentalization of ROS and redox networks to obtain a holistic understanding of how apical meristems adapt to stress.
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Affiliation(s)
- Vanesa B Tognetti
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Agnieszka Bielach
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Mónika Hrtyan
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
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153
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Raya-González J, López-Bucio JS, Prado-Rodríguez JC, Ruiz-Herrera LF, Guevara-García ÁA, López-Bucio J. The MEDIATOR genes MED12 and MED13 control Arabidopsis root system configuration influencing sugar and auxin responses. PLANT MOLECULAR BIOLOGY 2017; 95:141-156. [PMID: 28780645 DOI: 10.1007/s11103-017-0647-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 07/27/2017] [Indexed: 05/23/2023]
Abstract
Arabidopsis med12 and med13 mutants exhibit shoot and root phenotypes related to an altered auxin homeostasis. Sucrose supplementation reactivates both cell division and elongation in primary roots as well as auxin-responsive and stem cell niche gene expression in these mutants. An analysis of primary root growth of WT, med12, aux1-7 and med12 aux1 single and double mutants in response to sucrose and/or N-1-naphthylphthalamic acid (NPA) placed MED12 upstream of auxin transport for the sugar modulation of root growth. The MEDIATOR (MED) complex plays diverse functions in plant development, hormone signaling and biotic and abiotic stress tolerance through coordination of transcription. Here, we performed genetic, developmental, molecular and pharmacological analyses to characterize the role of MED12 and MED13 on the configuration of root architecture and its relationship with auxin and sugar responses. Arabidopsis med12 and med13 single mutants exhibit shoot and root phenotypes consistent with altered auxin homeostasis including altered primary root growth, lateral root development, and root hair elongation. MED12 and MED13 were required for activation of cell division and elongation in primary roots, as well as auxin-responsive and stem cell niche gene expression. Remarkably, most of these mutant phenotypes were rescued by supplying sucrose to the growth medium. The growth response of primary roots of WT, med12, aux1-7 and med12 aux1 single and double mutants to sucrose and application of auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) revealed the correlation of med12 phenotype with the activity of the auxin intake permease and suggests that MED12 acts upstream of AUX1 in the root growth response to sugar. These data provide compelling evidence that MEDIATOR links sugar sensing to auxin transport and distribution during root morphogenesis.
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Affiliation(s)
- Javier Raya-González
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico
| | | | - José Carlos Prado-Rodríguez
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico
| | - León Francisco Ruiz-Herrera
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico
| | | | - José López-Bucio
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico.
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154
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Zhang Y, Jiao Y, Jiao H, Zhao H, Zhu YX. Two-Step Functional Innovation of the Stem-Cell Factors WUS/WOX5 during Plant Evolution. Mol Biol Evol 2017; 34:640-653. [PMID: 28053005 PMCID: PMC5400392 DOI: 10.1093/molbev/msw263] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
WUS and WOX5, which are expressed, respectively, in the organizing center (OC) and the quiescent center (QC), are essential for shoot/root apical stem-cell maintenance in flowering plants. However, little is known about how these stem-cell factors evolved their functions in flowering plants. Here, we show that the WUS/WOX5 proteins acquired two distinct capabilities by a two-step functional innovation process in the course of plant evolution. The first-step is the apical stem-cell maintenance activity of WUS/WOX5, which originated in the common ancestor of ferns and seed plants, as evidenced by the interspecies complementation experiments, showing that ectopic expression of fern Ceratopteris richardii WUS-like (CrWUL) surrounding OC/QC, or exclusive OC-/QC-expressed gymnosperms/angiosperms WUS/WOX5 in Arabidopsis wus-1 and wox5-1 mutants, could rescue their phenotypes. The second-step is the intercellular mobility that emerged in the common ancestor of seed plants after divergence from the ferns. Evidence for this includes confocal imaging of GFP fusion proteins, showing that WUS/WOX5 from seed plants, rather than from the fern CrWUL, can migrate into cells adjacent to the OC/QC. Evolutionary analysis showed that the WUS-like gene was duplicated into two copies prior to the divergence of gymnosperms/angiosperms. Then the two gene copies (WUS and WOX5) have undergone similar levels of purifying selection, which is consistent with their conserved functions in angiosperm shoot/root stem-cell maintenance and floral organ formation. Our results highlight the critical roles and the essential prerequisites that the two-step functional innovation of these genes performs and represents in the origin of flowering plants.
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Affiliation(s)
- Yuzhou Zhang
- Institute for Advanced Studies, Wuhan University, Wuhan, China
| | - Yue Jiao
- Development Center for Science and Technology, Ministry of Agriculture, Beijing, China
| | - Hengwu Jiao
- Department of Ecology and Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Huabin Zhao
- Department of Ecology and Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yu-Xian Zhu
- Institute for Advanced Studies, Wuhan University, Wuhan, China.,Department of Plant Sciences, College of Life Sciences, Wuhan University, Wuhan, China
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155
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Yang ZB, Liu G, Liu J, Zhang B, Meng W, Müller B, Hayashi KI, Zhang X, Zhao Z, De Smet I, Ding Z. Synergistic action of auxin and cytokinin mediates aluminum-induced root growth inhibition in Arabidopsis. EMBO Rep 2017; 18:1213-1230. [PMID: 28600354 DOI: 10.15252/embr.201643806] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 04/27/2017] [Accepted: 05/02/2017] [Indexed: 11/09/2022] Open
Abstract
Auxin acts synergistically with cytokinin to control the shoot stem-cell niche, while both hormones act antagonistically to maintain the root meristem. In aluminum (Al) stress-induced root growth inhibition, auxin plays an important role. However, the role of cytokinin in this process is not well understood. In this study, we show that cytokinin enhances root growth inhibition under stress by mediating Al-induced auxin signaling. Al stress triggers a local cytokinin response in the root-apex transition zone (TZ) that depends on IPTs, which encode adenosine phosphate isopentenyltransferases and regulate cytokinin biosynthesis. IPTs are up-regulated specifically in the root-apex TZ in response to Al stress and promote local cytokinin biosynthesis and inhibition of root growth. The process of root growth inhibition is also controlled by ethylene signaling which acts upstream of auxin. In summary, different from the situation in the root meristem, auxin acts with cytokinin in a synergistic way to mediate aluminum-induced root growth inhibition in Arabidopsis.
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Affiliation(s)
- Zhong-Bao Yang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan, China
| | - Guangchao Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan, China
| | - Jiajia Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan, China
| | - Bing Zhang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan, China
| | - Wenjing Meng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, China
| | - Bruno Müller
- Institute of Plant Biology, University of Zurich, Zurich, Switzerland
| | - Ken-Ichiro Hayashi
- Department of Biochemistry, Okayama University of Science, Okayama, Japan
| | - Xiansheng Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, China
| | - Zhong Zhao
- School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Ive De Smet
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Zhaojun Ding
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan, China
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156
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Wójcikowska B, Gaj MD. Expression profiling of AUXIN RESPONSE FACTOR genes during somatic embryogenesis induction in Arabidopsis. PLANT CELL REPORTS 2017; 36:843-858. [PMID: 28255787 PMCID: PMC5486788 DOI: 10.1007/s00299-017-2114-3] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 02/01/2017] [Indexed: 05/18/2023]
Abstract
Extensive modulation of numerous ARF transcripts in the embryogenic culture of Arabidopsis indicates a substantial role of auxin signaling in the mechanism of somatic embryogenesis induction. Somatic embryogenesis (SE) is induced by auxin in plants and auxin signaling is considered to play a key role in the molecular mechanism that controls the embryogenic transition of plant somatic cells. Accordingly, the expression of AUXIN RESPONSE FACTOR (ARF) genes in embryogenic culture of Arabidopsis was analyzed. The study revealed that 14 of the 22 ARFs were transcribed during SE in Arabidopsis. RT-qPCR analysis indicated that the expression of six ARFs (ARF5, ARF6, ARF8, ARF10, ARF16, and ARF17) was significantly up-regulated, whereas five other genes (ARF1, ARF2, ARF3, ARF11, and ARF18) were substantially down-regulated in the SE-induced explants. The activity of ARFs during SE was also monitored with GFP reporter lines and the ARFs that were expressed in areas of the explants engaged in SE induction were detected. A functional test of ARFs transcribed during SE was performed and the embryogenic potential of the arf mutants and overexpressor lines was evaluated. ARFs with a significantly modulated expression during SE coupled with an impaired embryogenic response of the relevant mutant and/or overexpressor line, including ARF1, ARF2, ARF3, ARF5, ARF6, ARF8, and ARF11 were indicated as possibly being involved in SE induction. The study provides evidence that embryogenic induction strongly depends on ARFs, which are key regulators of the auxin signaling. Some clues on the possible functions of the candidate ARFs, especially ARF5, in the mechanism of embryogenic transition are discussed. The results provide guidelines for further research on the auxin-related functional genomics of SE and the developmental plasticity of somatic cells.
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Affiliation(s)
- Barbara Wójcikowska
- Department of Genetics, University of Silesia, ul. Jagiellońska 28, 40-032, Katowice, Poland
| | - Małgorzata D Gaj
- Department of Genetics, University of Silesia, ul. Jagiellońska 28, 40-032, Katowice, Poland.
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157
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Rast-Somssich MI, Žádníková P, Schmid S, Kieffer M, Kepinski S, Simon R. The Arabidopsis JAGGED LATERAL ORGANS (JLO) gene sensitizes plants to auxin. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2741-2755. [PMID: 28472464 PMCID: PMC5853575 DOI: 10.1093/jxb/erx131] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/23/2017] [Indexed: 06/07/2023]
Abstract
Plant growth and development of new organs depend on the continuous activity of the meristems. In the shoot, patterns of organ initiation are determined by PINFORMED (PIN)-dependent auxin distribution, while the undifferentiated state of meristem cells requires activity of KNOTTED LIKE HOMEOBOX (KNOX) transcription factors. Cell proliferation and differentiation of the root meristem are regulated by the largely antagonistic functions of auxin and cytokinins. It has previously been shown that the transcription factor JAGGED LATERAL ORGANS (JLO), a member of the LATERAL ORGAN BOUNDARY DOMAIN (LBD) family, coordinates KNOX and PIN expression in the shoot and promotes root meristem growth. Here we show that JLO is required for the establishment of the root stem cell niche, where it interacts with the auxin/PLETHORA pathway. Auxin signaling involves the AUX/IAA co-repressor proteins, ARF transcription factors and F-box receptors of the TIR1/AFB1-5 family. Because jlo mutants fail to degrade the AUX/IAA protein BODENLOS, root meristem development is inhibited. We also demonstrate that the expression levels of two auxin receptors, TIR1 and AFB1, are controlled by JLO dosage, and that the shoot and root defects of jlo mutants are alleviated in jlo plants expressing TIR1 and AFB1 from a transgene. The finding that the auxin sensitivity of a plant can be differentially regulated through control of auxin receptor expression can explain how different developmental processes can be integrated by the activity of a key transcription factor.
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Affiliation(s)
- Madlen I Rast-Somssich
- Institute for Developmental Genetics, Cluster of Excellence in Plant Sciences (CEPLAS), Heinrich Heine Universität, Universitätstrasse, Düsseldorf, Germany
| | - Petra Žádníková
- Institute for Developmental Genetics, Cluster of Excellence in Plant Sciences (CEPLAS), Heinrich Heine Universität, Universitätstrasse, Düsseldorf, Germany
| | - Stephan Schmid
- Institute for Developmental Genetics, Cluster of Excellence in Plant Sciences (CEPLAS), Heinrich Heine Universität, Universitätstrasse, Düsseldorf, Germany
| | - Martin Kieffer
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Stefan Kepinski
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Rüdiger Simon
- Institute for Developmental Genetics, Cluster of Excellence in Plant Sciences (CEPLAS), Heinrich Heine Universität, Universitätstrasse, Düsseldorf, Germany
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158
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García-Gómez ML, Azpeitia E, Álvarez-Buylla ER. A dynamic genetic-hormonal regulatory network model explains multiple cellular behaviors of the root apical meristem of Arabidopsis thaliana. PLoS Comput Biol 2017; 13:e1005488. [PMID: 28426669 PMCID: PMC5417714 DOI: 10.1371/journal.pcbi.1005488] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 05/04/2017] [Accepted: 03/30/2017] [Indexed: 11/18/2022] Open
Abstract
The study of the concerted action of hormones and transcription factors is fundamental to understand cell differentiation and pattern formation during organ development. The root apical meristem of Arabidopsis thaliana is a useful model to address this. It has a stem cell niche near its tip conformed of a quiescent organizer and stem or initial cells around it, then a proliferation domain followed by a transition domain, where cells diminish division rate before transiting to the elongation zone; here, cells grow anisotropically prior to their final differentiation towards the plant base. A minimal model of the gene regulatory network that underlies cell-fate specification and patterning at the root stem cell niche was proposed before. In this study, we update and couple such network with both the auxin and cytokinin hormone signaling pathways to address how they collectively give rise to attractors that correspond to the genetic and hormonal activity profiles that are characteristic of different cell types along A. thaliana root apical meristem. We used a Boolean model of the genetic-hormonal regulatory network to integrate known and predicted regulatory interactions into alternative models. Our analyses show that, after adding some putative missing interactions, the model includes the necessary and sufficient components and regulatory interactions to recover attractors characteristic of the root cell types, including the auxin and cytokinin activity profiles that correlate with different cellular behaviors along the root apical meristem. Furthermore, the model predicts the existence of activity configurations that could correspond to the transition domain. The model also provides a possible explanation for apparently paradoxical cellular behaviors in the root meristem. For example, how auxin may induce and at the same time inhibit WOX5 expression. According to the model proposed here the hormonal regulation of WOX5 might depend on the cell type. Our results illustrate how non-linear multi-stable qualitative network models can aid at understanding how transcriptional regulators and hormonal signaling pathways are dynamically coupled and may underlie both the acquisition of cell fate and the emergence of hormonal activity profiles that arise during complex organ development.
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Affiliation(s)
- Mónica L. García-Gómez
- Departamento de Ecología Funcional, Instituto de Ecología, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, México
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, México
| | - Eugenio Azpeitia
- INRIA project-team Virtual Plants, joint with CIRAD and INRA, Montpellier, France
| | - Elena R. Álvarez-Buylla
- Departamento de Ecología Funcional, Instituto de Ecología, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, México
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, México
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159
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Symplastic communication spatially directs local auxin biosynthesis to maintain root stem cell niche in Arabidopsis. Proc Natl Acad Sci U S A 2017; 114:4005-4010. [PMID: 28348232 DOI: 10.1073/pnas.1616387114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stem cells serve as the source of new cells for plant development. A group of stem cells form a stem cell niche (SCN) at the root tip and in the center of the SCN are slowly dividing cells called the quiescent center (QC). QC is thought to function as a signaling hub that inhibits differentiation of surrounding stem cells. Although it has been generally assumed that cell-to-cell communication provides positional information for QC and SCN maintenance, the tools for testing this hypothesis have long been lacking. Here we exploit a system that effectively blocks plasmodesmata (PD)-mediated signaling to explore how cell-to-cell communication functions in the SCN. We showed that the symplastic signaling between the QC and adjacent cells directs the formation of local auxin maxima and establishment of AP2-domain transcription factors, PLETHORA gradients. Interestingly we found symplastic signaling is essential for local auxin biosynthesis, which acts together with auxin polar transport to provide the guidance for local auxin enrichment. Therefore, we demonstrate the crucial role of cell-to-cell communication in the SCN maintenance and further uncover a mechanism by which symplastic signaling initiates and reinforces the positional information during stem cell maintenance via auxin regulation.
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160
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Yang ZB, He C, Ma Y, Herde M, Ding Z. Jasmonic Acid Enhances Al-Induced Root Growth Inhibition. PLANT PHYSIOLOGY 2017; 173:1420-1433. [PMID: 27932419 PMCID: PMC5291015 DOI: 10.1104/pp.16.01756] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 12/06/2016] [Indexed: 05/04/2023]
Abstract
Phytohormones such as ethylene and auxin are involved in the regulation of the aluminum (Al)-induced root growth inhibition. Although jasmonate (JA) has been reported to play a crucial role in the regulation of root growth and development in response to environmental stresses through interplay with ethylene and auxin, its role in the regulation of root growth response to Al stress is not yet known. In an attempt to elucidate the role of JA, we found that exogenous application of JA enhanced the Al-induced root growth inhibition. Furthermore, phenotype analysis with mutants defective in either JA biosynthesis or signaling suggests that JA is involved in the regulation of Al-induced root growth inhibition. The expression of the JA receptor CORONATINE INSENSITIVE1 (COI1) and the key JA signaling regulator MYC2 was up-regulated in response to Al stress in the root tips. This process together with COI1-mediated Al-induced root growth inhibition under Al stress was controlled by ethylene but not auxin. Transcriptomic analysis revealed that many responsive genes under Al stress were regulated by JA signaling. The differential responsive of microtubule organization-related genes between the wild-type and coi1-2 mutant is consistent with the changed depolymerization of cortical microtubules in coi1 under Al stress. In addition, ALMT-mediated malate exudation and thus Al exclusion from roots in response to Al stress was also regulated by COI1-mediated JA signaling. Together, this study suggests that root growth inhibition is regulated by COI1-mediated JA signaling independent from auxin signaling and provides novel insights into the phytohormone-mediated root growth inhibition in response to Al stress.
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161
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Tian H, Lv B, Ding T, Bai M, Ding Z. Auxin-BR Interaction Regulates Plant Growth and Development. FRONTIERS IN PLANT SCIENCE 2017; 8:2256. [PMID: 29403511 PMCID: PMC5778104 DOI: 10.3389/fpls.2017.02256] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/27/2017] [Indexed: 05/20/2023]
Abstract
Plants develop a high flexibility to alter growth, development, and metabolism to adapt to the ever-changing environments. Multiple signaling pathways are involved in these processes and the molecular pathways to transduce various developmental signals are not linear but are interconnected by a complex network and even feedback mutually to achieve the final outcome. This review will focus on two important plant hormones, auxin and brassinosteroid (BR), based on the most recent progresses about these two hormone regulated plant growth and development in Arabidopsis, and highlight the cross-talks between these two phytohormones.
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Affiliation(s)
- Huiyu Tian
- *Correspondence: Mingyi Bai, Zhaojun Ding, Huiyu Tian,
| | | | | | - Mingyi Bai
- *Correspondence: Mingyi Bai, Zhaojun Ding, Huiyu Tian,
| | - Zhaojun Ding
- *Correspondence: Mingyi Bai, Zhaojun Ding, Huiyu Tian,
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162
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Promchuea S, Zhu Y, Chen Z, Zhang J, Gong Z. ARF2 coordinates with PLETHORAs and PINs to orchestrate ABA-mediated root meristem activity in Arabidopsis . JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:30-43. [PMID: 28074634 DOI: 10.1111/jipb.12506] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 11/01/2016] [Indexed: 05/19/2023]
Abstract
Multiple hormones, including abscisic acid (ABA) and auxin, regulate cell division and differentiation of Arabidopsis root meristems. AUXIN RESPONSE FACTOR 2 (ARF2) functions as a negative regulator of ABA responses, as seed germination and primary root growth of arf2 mutants are hypersensitive to ABA. In this study, we found that ABA treatment reduced the expression levels of the PIN-FORMEDs (PIN) auxin efflux carriers, PIN1, PIN3, PIN4, and PIN7, to a greater extent in the root meristems of arf2-101 mutant than in the wild type. Also, arf2-101 pin1 and arf2-101 pin4 double mutants show less ABA-induced inhibition of root meristem activity than the arf2-101 mutants. Furthermore, ARF2 positively mediates the transcripts of transcription factor PLETHORA 1 (PLT1) gene but negatively mediates PLT2 at protein level in root meristems. Using a dexamethasone (DEX)-inducible transgenic line, Pro35S:PLT2-GR, we showed that PLT2 greatly promotes cell division and completely inhibits cell differentiation in root meristems of the arf2-101 mutant once PLT2 is induced by DEX, which can be partially reversed by ABA treatment, suggesting that ABA regulates root meristem activity in both ARF2-dependent and independent pathways. Our results uncover a complex regulatory architecture in which ARF2 coordinates with PLTs and PINs to orchestrate ABA-mediated regulation of root meristem activity in Arabidopsis.
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Affiliation(s)
- Sujittra Promchuea
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yujuan Zhu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhizhong Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jing Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- National Center for Plant Gene Research, Beijing 100193, China
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163
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Liu YY, Wang RL, Zhang P, Sun LL, Xu J. Involvement of reactive oxygen species in lanthanum-induced inhibition of primary root growth. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:6149-6159. [PMID: 27811082 PMCID: PMC5100026 DOI: 10.1093/jxb/erw379] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Although lanthanum (La) has been used as an agricultural plant growth stimulant for approximately 50 years, high concentrations are toxic to plants. Despite significant advances in recent years, the mechanisms underlying the effects of La on root system development remain unclear. Here, we report that a high concentration of La inhibits primary root (PR) elongation and induces lateral root (LR) development. La results in cell death in PR tips, thereby leading to the loss of meristematic cell division potential, stem cell niche activity, and auxin distribution in PR tips. Further analysis indicated that La induces reactive oxygen species (ROS) over-accumulation in PR tips. Reduction in ROS accumulation partially alleviated the inhibitory effects of La on PR elongation by improving cell survival in PR tips and thereby improving meristematic cell division potential and auxin distribution in PR tips. We also found ROS to be involved in La-induced endocytosis. Genetic analyses supported the described phenotype. Overall, our results indicate that La affects root growth, at least partially, by modulating ROS levels in roots to induce cell death in PR tips and subsequent auxin redistribution in roots, leading to remodeling of the root system architecture.
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Affiliation(s)
- Yang-Yang Liu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
| | - Ru-Ling Wang
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
| | - Ping Zhang
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
| | - Liang-Liang Sun
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
| | - Jin Xu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
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164
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A P-Loop NTPase Regulates Quiescent Center Cell Division and Distal Stem Cell Identity through the Regulation of ROS Homeostasis in Arabidopsis Root. PLoS Genet 2016; 12:e1006175. [PMID: 27583367 PMCID: PMC5008728 DOI: 10.1371/journal.pgen.1006175] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/15/2016] [Indexed: 01/03/2023] Open
Abstract
Reactive oxygen species (ROS) are recognized as important regulators of cell division and differentiation. The Arabidopsis thaliana P-loop NTPase encoded by APP1 affects root stem cell niche identity through its control of local ROS homeostasis. The disruption of APP1 is accompanied by a reduction in ROS level, a rise in the rate of cell division in the quiescent center (QC) and the promotion of root distal stem cell (DSC) differentiation. Both the higher level of ROS induced in the app1 mutant by exposure to methyl viologen (MV), and treatment with hydrogen peroxide (H2O2) rescued the mutant phenotype, implying that both the increased rate of cell division in the QC and the enhancement in root DSC differentiation can be attributed to a low level of ROS. APP1 is expressed in the root apical meristem cell mitochondria, and its product is associated with ATP hydrolase activity. The key transcription factors, which are defining root distal stem niche, such as SCARECROW (SCR) and SHORT ROOT (SHR) are both significantly down-regulated at both the transcriptional and protein level in the app1 mutant, indicating that SHR and SCR are important downstream targets of APP1-regulated ROS signaling to control the identity of root QC and DSCs. Reactive oxygen species (ROS) are recognized as important regulators of cell division and differentiation. In this study, we characterized an Arabidopsis thaliana P-loop NTPase encoded by APP1 regulates root stem cell niche identity through its control of local ROS homeostasis. The app1 mutant shows a reduction in ROS level, a rise in the rate of cell division in the quiescent center (QC) and the promotion of root distal stem cell (DSC) differentiation. The increased rate of cell division in the QC and the enhancement in root DSC differentiation in app1 can be attributed to a low level of ROS since both the exposure to methyl viologen (MV), and treatment with hydrogen peroxide (H2O2) rescued the mutant phenotype. APP1 is expressed in the root apical meristem cell mitochondria, and its product is associated with ATP hydrolase activity. The key transcription factors such as SCARECROW (SCR) and SHORT ROOT (SHR), which are defining root distal stem niche, are both greatly down-regulated at both the transcriptional and protein level in app1, indicating that SHR and SCR are important downstream targets of APP1-regulated ROS signaling to control the identity of root QC and DSCs.
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165
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Reactive Oxygen Species: From Harmful Molecules to Fine-Tuning Regulators of Stem Cell Niche Maintenance. PLoS Genet 2016; 12:e1006251. [PMID: 27583383 PMCID: PMC5008634 DOI: 10.1371/journal.pgen.1006251] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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166
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Palovaara J, de Zeeuw T, Weijers D. Tissue and Organ Initiation in the Plant Embryo: A First Time for Everything. Annu Rev Cell Dev Biol 2016; 32:47-75. [PMID: 27576120 DOI: 10.1146/annurev-cellbio-111315-124929] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Land plants can grow to tremendous body sizes, yet even the most complex architectures are the result of iterations of the same developmental processes: organ initiation, growth, and pattern formation. A central question in plant biology is how these processes are regulated and coordinated to allow for the formation of ordered, 3D structures. All these elementary processes first occur in early embryogenesis, during which, from a fertilized egg cell, precursors for all major tissues and stem cells are initiated, followed by tissue growth and patterning. Here we discuss recent progress in our understanding of this phase of plant life. We consider the cellular basis for multicellular development in 3D and focus on the genetic regulatory mechanisms that direct specific steps during early embryogenesis.
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Affiliation(s)
- Joakim Palovaara
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands;
| | - Thijs de Zeeuw
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands;
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands;
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167
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Araya T, von Wirén N, Takahashi H. CLE peptide signaling and nitrogen interactions in plant root development. PLANT MOLECULAR BIOLOGY 2016; 91:607-615. [PMID: 26994997 DOI: 10.1007/s11103-016-0472-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/11/2016] [Indexed: 06/05/2023]
Abstract
The CLAVATA signaling pathway is essential for the regulation of meristem activities in plants. This signaling pathway consists of small signaling peptides of the CLE family interacting with CLAVATA1 and leucine-rich repeat receptor-like kinases (LRR-RLKs). The peptide-receptor relationships determine the specificities of CLE-dependent signals controlling stem cell fate and differentiation that are critical for the establishment and maintenance of shoot and root apical meristems. Plants root systems are highly organized into three-dimensional structures for successful anchoring and uptake of water and mineral nutrients from the soil environment. Recent studies have provided evidence that CLE peptides and CLAVATA signaling pathways play pivotal roles in the regulation of lateral root development and systemic autoregulation of nodulation (AON) integrated with nitrogen (N) signaling mechanisms. Integrations of CLE and N signaling pathways through shoot-root vascular connections suggest that N demand modulates morphological control mechanisms and optimize N uptake as well as symbiotic N fixation in roots.
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Affiliation(s)
- Takao Araya
- Leibniz Institute of Plant Genetics and Crop Plant Research, 06466, Gatersleben, Germany
| | - Nicolaus von Wirén
- Leibniz Institute of Plant Genetics and Crop Plant Research, 06466, Gatersleben, Germany
| | - Hideki Takahashi
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI, 48824, USA.
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168
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Tyler L, Lee SJ, Young ND, DeIulio GA, Benavente E, Reagon M, Sysopha J, Baldini RM, Troìa A, Hazen SP, Caicedo AL. Population Structure in the Model Grass Is Highly Correlated with Flowering Differences across Broad Geographic Areas. THE PLANT GENOME 2016; 9. [PMID: 27898828 DOI: 10.3835/plantgenome2015.08.0074] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The small, annual grass (L.) Beauv., a close relative of wheat ( L.) and barley ( L.), is a powerful model system for cereals and bioenergy grasses. Genome-wide association studies (GWAS) of natural variation can elucidate the genetic basis of complex traits but have been so far limited in by the lack of large numbers of well-characterized and sufficiently diverse accessions. Here, we report on genotyping-by-sequencing (GBS) of 84 , seven , and three accessions with diverse geographic origins including Albania, Armenia, Georgia, Italy, Spain, and Turkey. Over 90,000 high-quality single-nucleotide polymorphisms (SNPs) distributed across the Bd21 reference genome were identified. Our results confirm the hybrid nature of the genome, which appears as a mosaic of -like and -like sequences. Analysis of more than 50,000 SNPs for the accessions revealed three distinct, genetically defined populations. Surprisingly, these genomic profiles are associated with differences in flowering time rather than with broad geographic origin. High levels of differentiation in loci associated with floral development support the differences in flowering phenology between populations. Genome-wide association studies combining genotypic and phenotypic data also suggest the presence of one or more photoperiodism, circadian clock, and vernalization genes in loci associated with flowering time variation within populations. Our characterization elucidates genes underlying population differences, expands the germplasm resources available for , and illustrates the feasibility and limitations of GWAS in this model grass.
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169
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Yu Q, Liu J, Zheng H, Jia Y, Tian H, Ding Z. Topoisomerase II-associated protein PAT1H1 is involved in the root stem cell niche maintenance in Arabidopsis thaliana. PLANT CELL REPORTS 2016; 35:1297-307. [PMID: 26956135 DOI: 10.1007/s00299-016-1961-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/21/2016] [Indexed: 05/15/2023]
Abstract
PAT1H1, one of the homologues of Topoisomerase II-associated protein, is involved in the maintenance of root stem cell niche through the interaction with NINJA. The root stem cell niche, which possesses four mitotically inactive quiescent cells (QC) and the surrounding mitotically active stem cells, is critical for root development in Arabidopsis thaliana. However, the molecular regulation of the maintenance of root stem cell niche identity is still not fully understood. Here we show that one of the homologues of Topoisomerase II-associated protein, here named as PAT1H1, could regulate root stem cell niche identity. The pat1h1 mutant showed higher frequency of QC cell division and root distal stem cell (DSC) differentiation. With a high expression in roots, PAT1H1 was found to interact with the jasmonic acid (JA) signalling negative regulator Novel Interactor of JAZ (NINJA) and thus regulate root DSC niche identity. Consistent with the active QC cell division, which rarely occurs in wild-type controls, the pat1h1 mutant displayed higher expression of CYCB1 in the root stem cell niche. Together our data reveals that PAT1H1 maintains root stem cell niche stability through the interaction with NINJA and the regulation of cell division.
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Affiliation(s)
- Qianqian Yu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Jiajia Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Huihui Zheng
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Yuebin Jia
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
| | - Huiyu Tian
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
| | - Zhaojun Ding
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China
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170
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Della Rovere F, Fattorini L, Ronzan M, Falasca G, Altamura MM. The quiescent center and the stem cell niche in the adventitious roots of Arabidopsis thaliana. PLANT SIGNALING & BEHAVIOR 2016; 11:e1176660. [PMID: 27089118 PMCID: PMC4973785 DOI: 10.1080/15592324.2016.1176660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Adventitious rooting is essential for the survival of numerous species from vascular cryptogams to monocots, and is required for successful micropropagation. The tissues involved in AR initiation may differ in planta and in in vitro systems. For example, in Arabidopsis thaliana, ARs originate from the hypocotyl pericycle in planta and the stem endodermis in in vitro cultured thin cell layers. The formation of adventitious roots (ARs) depends on numerous factors, among which the hormones, auxin, in particular. In both primary and lateral roots, growth depends on a functional stem cell niche in the apex, maintained by an active quiescent center (QC), and involving the expression of genes controlled by auxin and cytokinin. This review summarizes current knowledge about auxin and cytokinin control on genes involved in the definition and maintenance of QC, and stem cell niche, in the apex of Arabidopsis ARs in planta and in longitudinal thin cell layers.
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Affiliation(s)
- Federica Della Rovere
- Department of Environmental Biology, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy
| | - Laura Fattorini
- Department of Environmental Biology, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy
| | - Marilena Ronzan
- Department of Environmental Biology, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy
| | - Giuseppina Falasca
- Department of Environmental Biology, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy
| | - Maria Maddalena Altamura
- Department of Environmental Biology, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy
- Maria Maddalena Altamura
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171
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PP2A-3 interacts with ACR4 and regulates formative cell division in the Arabidopsis root. Proc Natl Acad Sci U S A 2016; 113:1447-52. [PMID: 26792519 DOI: 10.1073/pnas.1525122113] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In plants, the generation of new cell types and tissues depends on coordinated and oriented formative cell divisions. The plasma membrane-localized receptor kinase ARABIDOPSIS CRINKLY 4 (ACR4) is part of a mechanism controlling formative cell divisions in the Arabidopsis root. Despite its important role in plant development, very little is known about the molecular mechanism with which ACR4 is affiliated and its network of interactions. Here, we used various complementary proteomic approaches to identify ACR4-interacting protein candidates that are likely regulators of formative cell divisions and that could pave the way to unraveling the molecular basis behind ACR4-mediated signaling. We identified PROTEIN PHOSPHATASE 2A-3 (PP2A-3), a catalytic subunit of PP2A holoenzymes, as a previously unidentified regulator of formative cell divisions and as one of the first described substrates of ACR4. Our in vitro data argue for the existence of a tight posttranslational regulation in the associated biochemical network through reciprocal regulation between ACR4 and PP2A-3 at the phosphorylation level.
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172
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Sun Z, Wang Y, Mou F, Tian Y, Chen L, Zhang S, Jiang Q, Li X. Genome-Wide Small RNA Analysis of Soybean Reveals Auxin-Responsive microRNAs that are Differentially Expressed in Response to Salt Stress in Root Apex. FRONTIERS IN PLANT SCIENCE 2016; 6:1273. [PMID: 26834773 PMCID: PMC4716665 DOI: 10.3389/fpls.2015.01273] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/28/2015] [Indexed: 05/04/2023]
Abstract
Root growth and the architecture of the root system in Arabidopsis are largely determined by root meristematic activity. Legume roots show strong developmental plasticity in response to both abiotic and biotic stimuli, including symbiotic rhizobia. However, a global analysis of gene regulation in the root meristem of soybean plants is lacking. In this study, we performed a global analysis of the small RNA transcriptome of root tips from soybean seedlings grown under normal and salt stress conditions. In total, 71 miRNA candidates, including known and novel variants of 59 miRNA families, were identified. We found 66 salt-responsive miRNAs in the soybean root meristem; among them, 22 are novel miRNAs. Interestingly, we found auxin-responsive cis-elements in the promoters of many salt-responsive miRNAs, implying that these miRNAs may be regulated by auxin and auxin signaling plays a key role in regulating the plasticity of the miRNAome and root development in soybean. A functional analysis of miR399, a salt-responsive miRNA in the root meristem, indicates the crucial role of this miRNA in modulating soybean root developmental plasticity. Our data provide novel insight into the miRNAome-mediated regulatory mechanism in soybean root growth under salt stress.
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Affiliation(s)
- Zhengxi Sun
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesShijiazhuang, China
- University of Chinese Academy of SciencesBeijing, China
| | - Youning Wang
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Fupeng Mou
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesShijiazhuang, China
| | - Yinping Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesShijiazhuang, China
| | - Liang Chen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesShijiazhuang, China
| | - Senlei Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesShijiazhuang, China
| | - Qiong Jiang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesShijiazhuang, China
| | - Xia Li
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China
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173
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Wei Z, Li J. Brassinosteroids Regulate Root Growth, Development, and Symbiosis. MOLECULAR PLANT 2016; 9:86-100. [PMID: 26700030 DOI: 10.1016/j.molp.2015.12.003] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 10/29/2015] [Accepted: 12/07/2015] [Indexed: 05/19/2023]
Abstract
Brassinosteroids (BRs) are natural plant hormones critical for growth and development. BR deficient or signaling mutants show significantly shortened root phenotypes. However, for a long time, it was thought that these phenotypes were solely caused by reduced cell elongation in the mutant roots. Functions of BRs in regulating root development have been largely neglected. Nonetheless, recent detailed analyses, revealed that BRs are not only involved in root cell elongation but are also involved in many aspects of root development, such as maintenance of meristem size, root hair formation, lateral root initiation, gravitropic response, mycorrhiza formation, and nodulation in legume species. In this review, current findings on the functions of BRs in mediating root growth, development, and symbiosis are discussed.
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Affiliation(s)
- Zhuoyun Wei
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Jia Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
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174
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Druege U, Franken P, Hajirezaei MR. Plant Hormone Homeostasis, Signaling, and Function during Adventitious Root Formation in Cuttings. FRONTIERS IN PLANT SCIENCE 2016; 7:381. [PMID: 27064322 PMCID: PMC4814496 DOI: 10.3389/fpls.2016.00381] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 03/13/2016] [Indexed: 04/14/2023]
Abstract
Adventitious root (AR) formation in cuttings is a multiphase developmental process, resulting from wounding at the cutting site and isolation from the resource and signal network of the whole plant. Though, promotive effects of auxins are widely used for clonal plant propagation, the regulation and function of plant hormones and their intricate signaling networks during AR formation in cuttings are poorly understood. In this focused review, we discuss our recent publications on the involvement of polar auxin transport (PAT) and transcriptional regulation of auxin and ethylene action during AR formation in petunia cuttings in a broad context. Integrating new findings on cuttings of other plant species and general models on plant hormone networks, a model on the regulation and function of auxin, ethylene, and jasmonate in AR formation of cuttings is presented. PAT and cutting off from the basipetal auxin drain are considered as initial principles generating early accumulation of IAA in the rooting zone. This is expected to trigger a self-regulatory process of auxin canalization and maximization to responding target cells, there inducing the program of AR formation. Regulation of auxin homeostasis via auxin influx and efflux carriers, GH3 proteins and peroxidases, of flavonoid metabolism, and of auxin signaling via AUX/IAA proteins, TOPLESS, ARFs, and SAUR-like proteins are postulated as key processes determining the different phases of AR formation. NO and H2O2 mediate auxin signaling via the cGMP and MAPK cascades. Transcription factors of the GRAS-, AP2/ERF-, and WOX-families link auxin signaling to cell fate specification. Cyclin-mediated governing of the cell cycle, modifications of sugar metabolism and microtubule and cell wall remodeling are considered as important implementation processes of auxin function. Induced by the initial wounding and other abiotic stress factors, up-regulation of ethylene biosynthesis, and signaling via ERFs and early accumulation of jasmonic acid stimulate AR formation, while both pathways are linked to auxin. Future research on the function of candidate genes should consider their tissue-specific role and regulation by environmental factors. Furthermore, the whole cutting should be regarded as a system of physiological units with diverse functions specifically responding to the environment and determining the rooting response.
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Affiliation(s)
- Uwe Druege
- Department Plant Propagation, Leibniz Institute of Vegetable and Ornamental CropsErfurt, Germany
- *Correspondence:
| | - Philipp Franken
- Department Plant Propagation, Leibniz Institute of Vegetable and Ornamental CropsErfurt, Germany
| | - Mohammad R. Hajirezaei
- Department of Molecular Plant Nutrition, Leibniz Institute of Plant Genetics and Crop Plant ResearchGatersleben, Germany
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175
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Ye Y, Gong Z, Lu X, Miao D, Shi J, Lu J, Zhao Y. Germostatin resistance locus 1 encodes a PHD finger protein involved in auxin-mediated seed dormancy and germination. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:3-15. [PMID: 26611158 DOI: 10.1111/tpj.13086] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 05/06/2023]
Abstract
Seed dormancy and germination are important physiological processes during the life cycle of a seed plant. Recently, auxin has been characterized as a positive regulator that functions during seed dormancy and as a negative regulator during germination. Through chemical genetic screenings, we have identified a small molecule, germostatin (GS), which effectively inhibits seed germination in Arabidopsis. GSR1 (germostatin resistance locus 1) encodes a tandem plant homeodomain (PHD) finger protein, identified by screening GS-resistant mutants. Certain PHD fingers of GSR1 are capable of binding unmethylated H3K4, which has been reported as an epigenetic mark of gene transcriptional repression. Biochemical studies show that GSR1 physically interacts with the transcriptional repressor ARF16 and attenuates the intensity of interaction of IAA17/ARF16 by directly interacting with IAA17 to release ARF16. Further results show that axr3-1, arf10 arf16 are hyposensitive to GS, and gsr1 not only resists auxin-mediated inhibition of seed germination but also displays decreased dormancy. We therefore propose that GSR1 may form a co-repressor with ARF16 to regulate seed germination. Besides promoting auxin biosynthesis via upregulating expression of YUCCA1, GS also enhances auxin responses by inducing degradation of DΙΙ-VENUS and upregulating expression of DR5-GFP. In summary, we identified GSR1 as a member of the auxin-mediated seed germination genetic network, and GS, a small non-auxin molecule that specifically acts on auxin-mediated seed germination.
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Affiliation(s)
- Yajin Ye
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China
| | - Ziying Gong
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China
| | - Xiao Lu
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China
| | - Deyan Miao
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China
| | - Jianmin Shi
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China
| | - Juan Lu
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China
| | - Yang Zhao
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, 200032, Shanghai, China
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 68 Wenchang Road, 650000, Yunnan, China
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176
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Xu YX, Mao J, Chen W, Qian TT, Liu SC, Hao WJ, Li CF, Chen L. Identification and expression profiling of the auxin response factors (ARFs) in the tea plant (Camellia sinensis (L.) O. Kuntze) under various abiotic stresses. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 98:46-56. [PMID: 26637949 DOI: 10.1016/j.plaphy.2015.11.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 06/05/2023]
Abstract
Auxin response factor (ARF) proteins are a multigene family of regulators involved in various physiological and developmental processes in plants. However, their modes of action in the tea plant (Camellia sinensis) remain largely unknown. In this study, we identified 15 members of the tea ARF gene family, using the public information about C. sinensis, both in our laboratory, as well as in other laboratories, and analyzed their phylogenetic relationships, conserved domains and the compositions of the amino acids in the middle region. A comprehensive expression analysis in different tissues and organs revealed that many ARF genes were expressed in a tissue-specific manner, suggesting they have different functions in the growth and development processes of the tea plant. The expression analysis under three forms of auxin (indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid, naphthylacetic acid) treatment showed that the majority of the ARF genes were down-regulated in the shoots and up-regulated in the roots, suggesting opposite action mechanisms of the ARF genes in the shoots and roots. The expression levels of most ARF genes were changed under various phytohormone and abiotic stresses, indicating the ARF gene family plays important roles in various phytohormone and abiotic stress signals and may mediate the crosstalk between phytohormones and abiotic stresses. The current study provides basic information for the ARF genes of the tea plant and will pave the way for deciphering the precise role of ARFs in tea developmental processes and breeding stress-tolerant tea varieties.
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Affiliation(s)
- Yan-Xia Xu
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China
| | - Juan Mao
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China
| | - Wei Chen
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China
| | - Ting-Ting Qian
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China
| | - Sheng-Chuan Liu
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China
| | - Wan-Jun Hao
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China
| | - Chun-Fang Li
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China
| | - Liang Chen
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Science/ Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China.
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177
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Wang F, Muto A, Van de Velde J, Neyt P, Himanen K, Vandepoele K, Van Lijsebettens M. Functional Analysis of the Arabidopsis TETRASPANIN Gene Family in Plant Growth and Development. PLANT PHYSIOLOGY 2015; 169:2200-14. [PMID: 26417009 PMCID: PMC4634101 DOI: 10.1104/pp.15.01310] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 09/26/2015] [Indexed: 05/05/2023]
Abstract
TETRASPANIN (TET) genes encode conserved integral membrane proteins that are known in animals to function in cellular communication during gamete fusion, immunity reaction, and pathogen recognition. In plants, functional information is limited to one of the 17 members of the Arabidopsis (Arabidopsis thaliana) TET gene family and to expression data in reproductive stages. Here, the promoter activity of all 17 Arabidopsis TET genes was investigated by pAtTET::NUCLEAR LOCALIZATION SIGNAL-GREEN FLUORESCENT PROTEIN/β-GLUCURONIDASE reporter lines throughout the life cycle, which predicted functional divergence in the paralogous genes per clade. However, partial overlap was observed for many TET genes across the clades, correlating with few phenotypes in single mutants and, therefore, requiring double mutant combinations for functional investigation. Mutational analysis showed a role for TET13 in primary root growth and lateral root development and redundant roles for TET5 and TET6 in leaf and root growth through negative regulation of cell proliferation. Strikingly, a number of TET genes were expressed in embryonic and seedling progenitor cells and remained expressed until the differentiation state in the mature plant, suggesting a dynamic function over developmental stages. The cis-regulatory elements together with transcription factor-binding data provided molecular insight into the sites, conditions, and perturbations that affect TET gene expression and positioned the TET genes in different molecular pathways; the data represent a hypothesis-generating resource for further functional analyses.
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Affiliation(s)
- Feng Wang
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.); andDepartment of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata of Rende, Italy (A.M.)
| | - Antonella Muto
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.); andDepartment of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata of Rende, Italy (A.M.)
| | - Jan Van de Velde
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.); andDepartment of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata of Rende, Italy (A.M.)
| | - Pia Neyt
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.); andDepartment of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata of Rende, Italy (A.M.)
| | - Kristiina Himanen
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.); andDepartment of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata of Rende, Italy (A.M.)
| | - Klaas Vandepoele
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.); andDepartment of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata of Rende, Italy (A.M.)
| | - Mieke Van Lijsebettens
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.);Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium (F.W, A.M., J.V.d.V., P.N., K.H., K.V., M.V.L.); andDepartment of Biology, Ecology and Earth Sciences, University of Calabria, 87036 Arcavacata of Rende, Italy (A.M.)
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178
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Nizampatnam NR, Schreier SJ, Damodaran S, Adhikari S, Subramanian S. microRNA160 dictates stage-specific auxin and cytokinin sensitivities and directs soybean nodule development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:140-53. [PMID: 26287653 DOI: 10.1111/tpj.12965] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 07/31/2015] [Accepted: 08/13/2015] [Indexed: 05/20/2023]
Abstract
Legume nodules result from coordinated interactions between the plant and nitrogen-fixing rhizobia. The phytohormone cytokinin promotes nodule formation, and recent findings suggest that the phytohormone auxin inhibits nodule formation. Here we show that microRNA160 (miR160) is a key signaling element that determines the auxin/cytokinin balance during nodule development in soybean (Glycine max). miR160 appears to promote auxin activity by suppressing the levels of the ARF10/16/17 family of repressor ARF transcription factors. Using quantitative PCR assays and a fluorescence miRNA sensor, we show that miR160 levels are relatively low early during nodule formation and high in mature nodules. We had previously shown that ectopic expression of miR160 in soybean roots led to a severe reduction in nodule formation, coupled with enhanced sensitivity to auxin and reduced sensitivity to cytokinin. Here we show that exogenous cytokinin restores nodule formation in miR160 over-expressing roots. Therefore, low miR160 levels early during nodule development favor cytokinin activity required for nodule formation. Suppression of miR160 levels using a short tandem target mimic (STTM160) resulted in reduced sensitivity to auxin and enhanced sensitivity to cytokinin. In contrast to miR160 over-expressing roots, STTM160 roots had increased nodule formation, but nodule maturation was significantly delayed. Exogenous auxin partially restored proper nodule formation and maturation in STTM160 roots, suggesting that high miR160 activity later during nodule development favors auxin activity and promotes nodule maturation. Therefore, miR160 dictates developmental stage-specific sensitivities to auxin and cytokinin to direct proper nodule formation and maturation in soybean.
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Affiliation(s)
| | - Spencer John Schreier
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, 57007, USA
| | - Suresh Damodaran
- Department of Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Sajag Adhikari
- Department of Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Senthil Subramanian
- Department of Plant Science, South Dakota State University, Brookings, SD, 57007, USA
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, 57007, USA
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179
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Kong X, Lu S, Tian H, Ding Z. WOX5 is Shining in the Root Stem Cell Niche. TRENDS IN PLANT SCIENCE 2015; 20:601-603. [PMID: 26440429 DOI: 10.1016/j.tplants.2015.08.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 08/18/2015] [Accepted: 08/19/2015] [Indexed: 05/10/2023]
Abstract
The WUS-RELATED HOMEOBOX 5 (WOX5) gene is expressed in the quiescent center (QC) to regulate the columella stem cell (CSC) identity. Three recent reports not only show how WOX5 is controlled but also highlight the key role of WOX5 in root stem cell niche maintenance.
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Affiliation(s)
- Xiangpei Kong
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, Shandong, 250100, China
| | - Songchong Lu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, Shandong, 250100, China
| | - Huiyu Tian
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, Shandong, 250100, China
| | - Zhaojun Ding
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, Shandong, 250100, China.
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180
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Gaillochet C, Lohmann JU. The never-ending story: from pluripotency to plant developmental plasticity. Development 2015; 142:2237-49. [PMID: 26130755 PMCID: PMC4510588 DOI: 10.1242/dev.117614] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Plants are sessile organisms, some of which can live for over a thousand years. Unlike most animals, plants employ a post-embryonic mode of development driven by the continuous activity of pluripotent stem cells. Consequently, plants are able to initiate new organs over extended periods of time, and many species can readily replace lost body structures by de novo organogenesis. Classical studies have also shown that plant tissues have a remarkable capacity to undergo de-differentiation and proliferation in vitro, highlighting the fact that plant cell fate is highly plastic. This suggests that the mechanisms regulating fate transitions must be continuously active in most plant cells and that the control of cellular pluripotency lies at the core of diverse developmental programs. Here, we review how pluripotency is established in plant stem cell systems, how it is maintained during development and growth and re-initiated during regeneration, and how these mechanisms eventually contribute to the amazing developmental plasticity of plants.
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Affiliation(s)
- Christophe Gaillochet
- Department of Stem Cell Biology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany
| | - Jan U Lohmann
- Department of Stem Cell Biology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany
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181
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Boyer F, Simon R. Asymmetric cell divisions constructing Arabidopsis stem cell niches: the emerging role of protein phosphatases. PLANT BIOLOGY (STUTTGART, GERMANY) 2015; 17:935-45. [PMID: 26012742 DOI: 10.1111/plb.12352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/18/2015] [Indexed: 05/07/2023]
Abstract
Plant stem cell niches (SCNs) can be maintained in time through asymmetric cell divisions (ACDs) that allow the production of new cell types while constantly renewing the pools of stem cells (SCs). ACDs in plants require the asymmetric distribution of molecular components inside the cells as well as external asymmetric positional information. These two types of asymmetric information are controlled by inter- and intracellular signalling events. Phosphorylation of proteins is a major intermediate step in these signalling events, serving either as an activator or repressor of signalling, via fast auto- and trans-phosphorylation mechanisms. Whereas protein kinases, which phosphorylate proteins on serine, threonine or tyrosine residues, have been thoroughly studied, less attention has been given to protein phosphatases, which de-phosphorylate their protein targets on these same residues. Phosphatases modulate the activity of signalling pathways by balancing the action of kinases, and are therefore critical in the regulation of ACDs in plants. In this review, we first present the different types of ACDs that operate during Arabidopsis embryonic and post-embryonic development and participate in the construction and maintenance of its root and shoot SCNs; we then give a brief description of the main protein phosphatases so far described in the Arabidopsis genome; and finally discuss their functions toward the regulation of the ACDs introduced in the first part of the paper.
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Affiliation(s)
- F Boyer
- Institute of Developmental Genetics, Heinrich Heine University, Düsseldorf, Germany
| | - R Simon
- Institute of Developmental Genetics, Heinrich Heine University, Düsseldorf, Germany
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182
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Jia Y, Tian H, Li H, Yu Q, Wang L, Friml J, Ding Z. The Arabidopsis thaliana elongator complex subunit 2 epigenetically affects root development. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:4631-42. [PMID: 25998905 PMCID: PMC4507768 DOI: 10.1093/jxb/erv230] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The elongator complex subunit 2 (ELP2) protein, one subunit of an evolutionarily conserved histone acetyltransferase complex, has been shown to participate in leaf patterning, plant immune and abiotic stress responses in Arabidopsis thaliana. Here, its role in root development was explored. Compared to the wild type, the elp2 mutant exhibited an accelerated differentiation of its root stem cells and cell division was more active in its quiescent centre (QC). The key transcription factors responsible for maintaining root stem cell and QC identity, such as AP2 transcription factors PLT1 (PLETHORA1) and PLT2 (PLETHORA2), GRAS transcription factors such as SCR (SCARECROW) and SHR (SHORT ROOT) and WUSCHEL-RELATED HOMEOBOX5 transcription factor WOX5, were all strongly down-regulated in the mutant. On the other hand, expression of the G2/M transition activator CYCB1 was substantially induced in elp2. The auxin efflux transporters PIN1 and PIN2 showed decreased protein levels and PIN1 also displayed mild polarity alterations in elp2, which resulted in a reduced auxin content in the root tip. Either the acetylation or methylation level of each of these genes differed between the mutant and the wild type, suggesting that the ELP2 regulation of root development involves the epigenetic modification of a range of transcription factors and other developmental regulators.
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Affiliation(s)
- Yuebin Jia
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan 250100, China
| | - Huiyu Tian
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan 250100, China
| | - Hongjiang Li
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Qianqian Yu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan 250100, China
| | - Lei Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jiri Friml
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Zhaojun Ding
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan 250100, China
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183
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Lee HS, Kim Y, Pham G, Kim JW, Song JH, Lee Y, Hwang YS, Roux SJ, Kim SH. Brassinazole resistant 1 (BZR1)-dependent brassinosteroid signalling pathway leads to ectopic activation of quiescent cell division and suppresses columella stem cell differentiation. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:4835-49. [PMID: 26136267 PMCID: PMC4507784 DOI: 10.1093/jxb/erv316] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Previous publications have shown that BRI1 EMS suppressor 1 (BES1), a positive regulator of the brassinosteroid (BR) signalling pathway, enhances cell divisions in the quiescent centre (QC) and stimulates columella stem cell differentiation. Here, it is demonstrated that BZR1, a BES1 homologue, also promotes cell divisions in the QC, but it suppresses columella stem cell differentiation, opposite to the action of BES1. In addition, BR and its BZR1-mediated signalling pathway are shown to alter the expression/subcellular distribution of pin-formed (PINs), which may result in changes in auxin movement. BR promotes intense nuclear accumulation of BZR1 in the root tip area, and the binding of BZR1 to the promoters of several root development-regulating genes, modulating their expression in the root stem cell niche area. These BZR1-mediated signalling cascades may account for both the ectopic activation of QC cell divisions as well as the suppression of the columella stem cell differentiation. They could also inhibit auxin-dependent distal stem cell differentiation by antagonizing the auxin/WOX5-dependent pathway. In conclusion, BZR1-/BES1-mediated BR signalling pathways show differential effects on the maintenance of root apical meristem activities: they stimulate ectopic QC division while they show opposite effects on the differentiation of distal columella stem cells in a BR concentration- and BZR1-/BES1-dependent manner.
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Affiliation(s)
- Hak-Soo Lee
- Division of Biological Science and Technology, Yonsei University, Wonju, 220-710, Republic of Korea
| | - Yoon Kim
- Division of Biological Science and Technology, Yonsei University, Wonju, 220-710, Republic of Korea
| | - Giang Pham
- Division of Biological Science and Technology, Yonsei University, Wonju, 220-710, Republic of Korea
| | - Ju Won Kim
- Division of Biological Science and Technology, Yonsei University, Wonju, 220-710, Republic of Korea
| | - Ji-Hye Song
- Division of Biological Science and Technology, Yonsei University, Wonju, 220-710, Republic of Korea
| | - Yew Lee
- Division of Biological Science and Technology, Yonsei University, Wonju, 220-710, Republic of Korea Department of Life Science, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Yong-Sic Hwang
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea
| | - Stanley J Roux
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Soo-Hwan Kim
- Division of Biological Science and Technology, Yonsei University, Wonju, 220-710, Republic of Korea
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184
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Richards S, Wink RH, Simon R. Mathematical modelling of WOX5- and CLE40-mediated columella stem cell homeostasis in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:5375-84. [PMID: 26019259 PMCID: PMC4526915 DOI: 10.1093/jxb/erv257] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The root meristem of Arabidopsis thaliana harbours a pool of stem cells, which divide to give rise to the differentiated cells of the various root tissues. Regulatory networks of inter-cellular signalling molecules control the homeostasis of stem cell number and position so that both stem and differentiated cells are consistently available. This work focuses on the transcription factor WUSCHEL-RELATED HOMEOBOX 5 (WOX5), the signalling peptide CLAVATA3/EMBRYO-SURROUNDING REGION 40 (CLE40) and the feedback loops involving them, which maintain the columella stem cells (CSCs). WOX5 signals from the quiescent centre (QC) to promote stem cell fate, while CLE40 is secreted from the differentiated columella cells (CCs) to promote differentiation. Our analyses of mathematical models of this network show that, when cell fate is controlled primarily by antagonistic factors, homeostasis requires a spatial component and inter-cellular signalling. We have also found that WOX5 contributes to, but is not absolutely necessary for, CSC maintenance. Furthermore, our modelling led us to postulate an additional signalling molecule that promotes CSC maintenance. We propose that this WOX5-independent signal originates in the QC, is targeted by CLE40 signalling and is capable of maintaining CSCs.
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Affiliation(s)
- Sarah Richards
- Institute of Developmental Genetics, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Rene H Wink
- Institute of Developmental Genetics, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Rüdiger Simon
- Institute of Developmental Genetics, Heinrich Heine University, 40225 Düsseldorf, Germany
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185
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Niu Y, Jin G, Li X, Tang C, Zhang Y, Liang Y, Yu J. Phosphorus and magnesium interactively modulate the elongation and directional growth of primary roots in Arabidopsis thaliana (L.) Heynh. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:3841-54. [PMID: 25922494 PMCID: PMC4473981 DOI: 10.1093/jxb/erv181] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A balanced supply of essential nutrients is an important factor influencing root architecture in many plants, yet data related to the interactive effects of two nutrients on root growth are limited. Here, we investigated the interactive effect between phosphorus (P) and magnesium (Mg) on root growth of Arabidopsis grown in pH-buffered agar medium at different P and Mg levels. The results showed that elongation and deviation of primary roots were directly correlated with the amount of P added to the medium but could be modified by the Mg level, which was related to the root meristem activity and stem-cell division. High P enhanced while low P decreased the tip-focused fluorescence signal of auxin biosynthesis, transport, and redistribution during elongation of primary roots; these effects were greater under low Mg than under high Mg. The altered root growth in response to P and Mg supply was correlated with AUX1, PIN2, and PIN3 mRNA abundance and expression and the accumulation of the protein. Application of either auxin influx inhibitor or efflux inhibitor inhibited the elongation and increased the deviation angle of primary roots, and decreased auxin level in root tips. Furthermore, the auxin-transport mutants aux1-22 and eir1-1 displayed reduced root growth and increased the deviation angle. Our data suggest a profound effect of the combined supply of P and Mg on the development of root morphology in Arabidopsis through auxin signals that modulate the elongation and directional growth of primary root and the expression of root differentiation and development genes.
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Affiliation(s)
- Yaofang Niu
- Department of Horticulture, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou 310058, PR China College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Gulei Jin
- College of Agricultural and Biotechnology, Zhejiang University, Hangzhou 310058, PR China
| | - Xin Li
- Tea Research Institute, Chinese Academy of Agricultural Science, Hangzhou, 310008, PR China
| | - Caixian Tang
- Centre for AgriBioscience, La Trobe University, Melbourne Campus, Victoria 3086, Australia
| | - Yongsong Zhang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Yongchao Liang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Jingquan Yu
- Department of Horticulture, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou 310058, PR China
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186
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Lutova LA, Dodueva IE, Lebedeva MA, Tvorogova VE. Transcription factors in developmental genetics and the evolution of higher plants. RUSS J GENET+ 2015. [DOI: 10.1134/s1022795415030084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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187
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Kinoshita A, ten Hove CA, Tabata R, Yamada M, Shimizu N, Ishida T, Yamaguchi K, Shigenobu S, Takebayashi Y, Iuchi S, Kobayashi M, Kurata T, Wada T, Seo M, Hasebe M, Blilou I, Fukuda H, Scheres B, Heidstra R, Kamiya Y, Sawa S. A plant U-box protein, PUB4, regulates asymmetric cell division and cell proliferation in the root meristem. Development 2015; 142:444-53. [PMID: 25605779 DOI: 10.1242/dev.113167] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The root meristem (RM) is a fundamental structure that is responsible for postembryonic root growth. The RM contains the quiescent center (QC), stem cells and frequently dividing meristematic cells, in which the timing and the frequency of cell division are tightly regulated. In Arabidopsis thaliana, several gain-of-function analyses have demonstrated that peptide ligands of the Clavata3 (CLV3)/embryo surrounding region-related (CLE) family are important for maintaining RM size. Here, we demonstrate that a plant U-box E3 ubiquitin ligase, PUB4, is a novel downstream component of CLV3/CLE signaling in the RM. Mutations in PUB4 reduced the inhibitory effect of exogenous CLV3/CLE peptide on root cell proliferation and columella stem cell maintenance. Moreover, pub4 mutants grown without exogenous CLV3/CLE peptide exhibited characteristic phenotypes in the RM, such as enhanced root growth, increased number of cortex/endodermis stem cells and decreased number of columella layers. Our phenotypic and gene expression analyses indicated that PUB4 promotes expression of a cell cycle regulatory gene, CYCD6;1, and regulates formative periclinal asymmetric cell divisions in endodermis and cortex/endodermis initial daughters. These data suggest that PUB4 functions as a global regulator of cell proliferation and the timing of asymmetric cell division that are important for final root architecture.
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Affiliation(s)
- Atsuko Kinoshita
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Colette A ten Hove
- Molecular Genetics, Department of Biology, Utrecht University, Utrecht 3584 CH, The Netherlands Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, Wageningen 6703HA, The Netherlands
| | - Ryo Tabata
- Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Masashi Yamada
- Department of Biology and Institute for Genome Science and Policy Center for Systems Biology, Duke University, Durham, NC 27708, USA
| | - Noriko Shimizu
- Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Takashi Ishida
- Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Katsushi Yamaguchi
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Shuji Shigenobu
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki 444-8585, Japan School of Life Science, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
| | - Yumiko Takebayashi
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Satoshi Iuchi
- RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Masatomo Kobayashi
- RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Tetsuya Kurata
- Graduate School of Biological Sciences, NAIST, Ikoma 630-0192, Japan
| | - Takuji Wada
- Graduate School of Biosphere Sciences, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Mitsunori Seo
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Mitsuyasu Hasebe
- School of Life Science, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Ikram Blilou
- Molecular Genetics, Department of Biology, Utrecht University, Utrecht 3584 CH, The Netherlands Plant Developmental Biology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6700AP, The Netherlands
| | - Hiroo Fukuda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ben Scheres
- Molecular Genetics, Department of Biology, Utrecht University, Utrecht 3584 CH, The Netherlands Plant Developmental Biology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6700AP, The Netherlands
| | - Renze Heidstra
- Molecular Genetics, Department of Biology, Utrecht University, Utrecht 3584 CH, The Netherlands Plant Developmental Biology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6700AP, The Netherlands
| | - Yuji Kamiya
- RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama 230-0045, Japan
| | - Shinichiro Sawa
- Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
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188
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Ji H, Wang S, Li K, Szakonyi D, Koncz C, Li X. PRL1 modulates root stem cell niche activity and meristem size through WOX5 and PLTs in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:399-412. [PMID: 25438658 DOI: 10.1111/tpj.12733] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 11/20/2014] [Accepted: 11/21/2014] [Indexed: 05/13/2023]
Abstract
The stem cell niche in the root meristem maintains pluripotent stem cells to ensure a constant supply of cells for root growth. Despite extensive progress, the molecular mechanisms through which root stem cell fates and stem cell niche activity are determined remain largely unknown. In Arabidopsis thaliana, the Pleiotropic Regulatory Locus 1 (PRL1) encodes a WD40-repeat protein subunit of the spliceosome-activating Nineteen Complex (NTC) that plays a role in multiple stress, hormone and developmental signaling pathways. Here, we show that PRL1 is involved in the control of root meristem size and root stem cell niche activity. PRL1 is strongly expressed in the root meristem and its loss of function mutation results in disorganization of the quiescent center (QC), premature stem cell differentiation, aberrant cell division, and reduced root meristem size. Our genetic studies indicate that PRL1 is required for confined expression of the homeodomain transcription factor WOX5 in the QC and acts upstream of the transcription factor PLETHORA (PLT) in modulating stem cell niche activity and root meristem size. These findings define a role for PRL1 as an important determinant of PLT signaling that modulates maintenance of the stem cell niche and root meristem size.
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Affiliation(s)
- Hongtao Ji
- The State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Research Resources, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 286 Huaizhong Road, Shijiazhuang, Hebei, 050021, China
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189
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Wang Z, Mao JL, Zhao YJ, Li CY, Xiang CB. L-Cysteine inhibits root elongation through auxin/PLETHORA and SCR/SHR pathway in Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:186-97. [PMID: 24798139 DOI: 10.1111/jipb.12213] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 05/04/2014] [Indexed: 05/03/2023]
Abstract
L-Cysteine plays a prominent role in sulfur metabolism of plants. However, its role in root development is largely unknown. Here, we report that L-cysteine reduces primary root growth in a dosage-dependent manner. Elevating cellular L-cysteine level by exposing Arabidopsis thaliana seedlings to high L-cysteine, buthionine sulphoximine, or O-acetylserine leads to altered auxin maximum in root tips, the expression of quiescent center cell marker as well as the decrease of the auxin carriers PIN1, PIN2, PIN3, and PIN7 of primary roots. We also show that high L-cysteine significantly reduces the protein level of two sets of stem cell specific transcription factors PLETHORA1/2 and SCR/SHR. However, L-cysteine does not downregulate the transcript level of PINs, PLTs, or SCR/SHR, suggesting that an uncharacterized post-transcriptional mechanism may regulate the accumulation of PIN, PLT, and SCR/SHR proteins and auxin transport in the root tips. These results suggest that endogenous L-cysteine level acts to maintain root stem cell niche by regulating basal- and auxin-induced expression of PLT1/2 and SCR/SHR. L-Cysteine may serve as a link between sulfate assimilation and auxin in regulating root growth.
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Affiliation(s)
- Zhen Wang
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230027, China
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190
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Carretero-Paulet L, Librado P, Chang TH, Ibarra-Laclette E, Herrera-Estrella L, Rozas J, Albert VA. High Gene Family Turnover Rates and Gene Space Adaptation in the Compact Genome of the Carnivorous Plant Utricularia gibba. Mol Biol Evol 2015; 32:1284-95. [PMID: 25637935 DOI: 10.1093/molbev/msv020] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Utricularia gibba is an aquatic carnivorous plant with highly specialized morphology, featuring fibrous floating networks of branches and leaf-like organs, no recognizable roots, and bladder traps that capture and digest prey. We recently described the compressed genome of U. gibba as sufficient to control the development and reproduction of a complex organism. We hypothesized intense deletion pressure as a mechanism whereby most noncoding DNA was deleted, despite evidence for three independent whole-genome duplications (WGDs). Here, we explore the impact of intense genome fractionation in the evolutionary dynamics of U. gibba's functional gene space. We analyze U. gibba gene family turnover by modeling gene gain/death rates under a maximum-likelihood statistical framework. In accord with our deletion pressure hypothesis, we show that the U. gibba gene death rate is significantly higher than those of four other eudicot species. Interestingly, the gene gain rate is also significantly higher, likely reflecting the occurrence of multiple WGDs and possibly also small-scale genome duplications. Gene ontology enrichment analyses of U. gibba-specific two-gene orthogroups, multigene orthogroups, and singletons highlight functions that may represent adaptations in an aquatic carnivorous plant. We further discuss two homeodomain transcription factor gene families (WOX and HDG/HDZIP-IV) showing conspicuous differential expansions and contractions in U. gibba. Our results 1) reconcile the compactness of the U. gibba genome with its accommodation of a typical number of genes for a plant genome, and 2) highlight the role of high gene family turnover in the evolutionary diversification of U. gibba's functional gene space and adaptations to its unique lifestyle and highly specialized body plan.
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Affiliation(s)
| | - Pablo Librado
- Departament de Genètica and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Tien-Hao Chang
- Department of Biological Sciences, University at Buffalo, Buffalo, NY
| | - Enrique Ibarra-Laclette
- Laboratorio Nacional de Genómica Para la Biodiversidad-Langebio/Unidad de Genómica Avanzada UGA, Centro de Investigación y Estudios Avanzados del IPN, Irapuato, Guanajuato, México
| | - Luis Herrera-Estrella
- Laboratorio Nacional de Genómica Para la Biodiversidad-Langebio/Unidad de Genómica Avanzada UGA, Centro de Investigación y Estudios Avanzados del IPN, Irapuato, Guanajuato, México
| | - Julio Rozas
- Departament de Genètica and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Victor A Albert
- Department of Biological Sciences, University at Buffalo, Buffalo, NY
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191
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Zhang Y, Jiao Y, Liu Z, Zhu YX. ROW1 maintains quiescent centre identity by confining WOX5 expression to specific cells. Nat Commun 2015; 6:6003. [PMID: 25631790 PMCID: PMC4316744 DOI: 10.1038/ncomms7003] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 12/02/2014] [Indexed: 12/23/2022] Open
Abstract
The quiescent centre (QC) in the Arabidopsis root apical meristem is essential for stem cell organization. Here we show that the loss of REPRESSOR OF WUSCHEL1 (ROW1), a PHD domain-containing protein, leads to QC failure, defects in cell differentiation and ectopic expression of WUSCHEL-RELATED HOMEOBOX 5 (WOX5) in cells that normally express ROW1. The wox5-1/row1-3 double mutants show similar phenotypes to wox5-1 indicating that WOX5 is epistatic to ROW1. ROW1 specifically binds trimethylated histone H3 lysine 4 (H3K4me3) in the WOX5 promoter region to repress its transcription. QC expression of ROW1 results in a wox5-1-like phenotype with undetectable WOX5 transcripts. We propose that ROW1 is essential for QC maintenance and for stem cell niche development through the repression of WOX5 in the proximal meristem. The quiescent centre controls stem cell differentiation at the root apical meristem. Here Zhang et al. propose that ROW1 maintains meristem cell identity by repressing expression of the WOX5 transcription factor in the proximal meristem zone, thus confining its activity to the quiescent centre.
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Affiliation(s)
- Yuzhou Zhang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Yue Jiao
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Zhaohui Liu
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Yu-Xian Zhu
- 1] State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China [2] National Center for Plant Gene Research (Beijing), Beijing 100101, China
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192
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Hong JH, Chu H, Zhang C, Ghosh D, Gong X, Xu J. A quantitative analysis of stem cell homeostasis in the Arabidopsis columella root cap. FRONTIERS IN PLANT SCIENCE 2015; 6:206. [PMID: 25870608 PMCID: PMC4375977 DOI: 10.3389/fpls.2015.00206] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/15/2015] [Indexed: 05/20/2023]
Abstract
The Lugol's staining method has been widely used to detect changes in the maintenance of stem cell fate in the columella root cap of Arabidopsis roots since the late 1990s. However, various limitations of this method demand for additional or complementary new approaches. For instance, it is unable to reveal the division rate of columella root cap stem cells. Here we report that, by labeling dividing stem cells with 5-ethynyl-2'-deoxyuridine (EdU), the number and distribution of their labeled progeny can be studied so that the division rate of stem cells can be measured quantitatively and in addition, that the progression of stem cell progeny differentiation can be assessed in combination with Lugol's staining. EdU staining takes few hours and visualization of the stain characteristics of columella root cap can be performed easily under confocal microscopes. This simple technology, when used together with Lugol's staining, provides a novel quantitative method to study the dynamics of stem cell behavior that govern homeostasis in the Arabidopsis columella root cap.
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Affiliation(s)
- Jing Han Hong
- Department of Biological Sciences, National University of Singapore, Singapore
- NUS Centre for BioImaging Sciences, National University of Singapore, Singapore
| | - Huangwei Chu
- Department of Biological Sciences, National University of Singapore, Singapore
- NUS Centre for BioImaging Sciences, National University of Singapore, Singapore
| | - Chen Zhang
- Department of Biological Sciences, National University of Singapore, Singapore
- NUS Centre for BioImaging Sciences, National University of Singapore, Singapore
| | - Dipanjana Ghosh
- Department of Biological Sciences, National University of Singapore, Singapore
- NUS Centre for BioImaging Sciences, National University of Singapore, Singapore
| | - Ximing Gong
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Jian Xu
- Department of Biological Sciences, National University of Singapore, Singapore
- NUS Centre for BioImaging Sciences, National University of Singapore, Singapore
- *Correspondence: Jian Xu, Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
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193
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Zhang F, Tadege M. Repression of AS2 by WOX family transcription factors is required for leaf development in Medicago and Arabidopsis. PLANT SIGNALING & BEHAVIOR 2015; 10:e993291. [PMID: 25807065 PMCID: PMC4623463 DOI: 10.4161/15592324.2014.993291] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
WOX transcription factors are key regulators of meristematic activity in plants. The Medicago WOX gene, STF, functions in maintenance of leaf marginal meristem, analogous to the function of WUS in the shoot apical meristem. Both STF and WUS directly repress AS2 expression in their respective domains. Ectopic expression of AS2 with WUS promoter leads to a narrow leaf phenotype and other phenotypes similar to the wus mutant. We also found that a wox1 prs wus triple mutant produces much narrower leaf blades than the wox1 prs double mutant, indicating that WUS genetically interacts with WOX1 and PRS in Arabidopsis leaf blade development. Our data points to a general requirement for AS2 repression in meristematic regions to allow cell proliferation.
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Affiliation(s)
- Fei Zhang
- Department of Plant and Soil Sciences; Institute for Agricultural Biosciences; Oklahoma State University; Ardmore, OK USA
| | - Million Tadege
- Department of Plant and Soil Sciences; Institute for Agricultural Biosciences; Oklahoma State University; Ardmore, OK USA
- Correspondence to: Million Tadege;
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194
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Drisch RC, Stahl Y. Function and regulation of transcription factors involved in root apical meristem and stem cell maintenance. FRONTIERS IN PLANT SCIENCE 2015; 6:505. [PMID: 26217359 PMCID: PMC4491714 DOI: 10.3389/fpls.2015.00505] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/23/2015] [Indexed: 05/20/2023]
Abstract
Plant roots are essential for overall plant development, growth, and performance by providing anchorage in the soil and uptake of nutrients and water. The primary root of higher plants derives from a group of pluripotent, mitotically active stem cells residing in the root apical meristem (RAM) which provides the basis for growth, development, and regeneration of the root. The stem cells in the Arabidopsis thaliana RAM are surrounding the quiescent center (QC), which consists of a group of rarely dividing cells. The QC maintains the stem cells in a non-cell-autonomous manner and prevents them from differentiation. The necessary dynamic but also tight regulation of the transition from stem cell fate to differentiation most likely requires complex regulatory mechanisms to integrate external and internal cues. Transcription factors play a central role in root development and are regulated by phytohormones, small signaling molecules, and miRNAs. In this review we give a comprehensive overview about the function and regulation of specific transcription factors controlling stem cell fate and root apical meristem maintenance and discuss the possibility of TF complex formation, subcellular translocations and cell-to-cell movement functioning as another level of regulation.
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Affiliation(s)
| | - Yvonne Stahl
- *Correspondence: Yvonne Stahl, Institute for Developmental Genetics, Heinrich-Heine-University, Universitätsstrasse 1, Düsseldorf, NRW, Germany,
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195
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Cole RA, McInally SA, Fowler JE. Developmentally distinct activities of the exocyst enable rapid cell elongation and determine meristem size during primary root growth in Arabidopsis. BMC PLANT BIOLOGY 2014; 14:386. [PMID: 25551204 PMCID: PMC4302519 DOI: 10.1186/s12870-014-0386-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/15/2014] [Indexed: 05/20/2023]
Abstract
BACKGROUND Exocytosis is integral to root growth: trafficking components of systems that control growth (e.g., PIN auxin transport proteins) to the plasma membrane, and secreting materials that expand the cell wall to the apoplast. Spatiotemporal regulation of exocytosis in eukaryotes often involves the exocyst, an octameric complex that tethers selected secretory vesicles to specific sites on the plasma membrane and facilitates their exocytosis. We evaluated Arabidopsis lines with mutations in four exocyst components (SEC5, SEC8, EXO70A1 and EXO84B) to explore exocyst function in primary root growth. RESULTS The mutants have root growth rates that are 82% to 11% of wild-type. Even in lines with the most severe defects, the organization of the quiescent center and tissue layers at the root tips appears similar to wild-type, although meristematic, transition, and elongation zones are shorter. Reduced cell production rates in the mutants are due to the shorter meristems, but not to lengthened cell cycles. Additionally, mutants demonstrate reduced anisotropic cell expansion in the elongation zone, but not the meristematic zone, resulting in shorter mature cells that are similar in shape to wild-type. As expected, hypersensitivity to brefeldin A links the mutant root growth defect to altered vesicular trafficking. Several experimental approaches (e.g., dose-response measurements, localization of signaling components) failed to identify aberrant auxin or brassinosteroid signaling as a primary driver for reduced root growth in exocyst mutants. CONCLUSIONS The exocyst participates in two spatially distinct developmental processes, apparently by mechanisms not directly linked to auxin or brassinosteroid signaling pathways, to help establish root meristem size, and to facilitate rapid cell expansion in the elongation zone.
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Affiliation(s)
- Rex A Cole
- Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, 97331 OR USA
| | - Samantha A McInally
- Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, 97331 OR USA
| | - John E Fowler
- Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, 97331 OR USA
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196
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Arabidopsis ribosomal proteins control vacuole trafficking and developmental programs through the regulation of lipid metabolism. Proc Natl Acad Sci U S A 2014; 112:E89-98. [PMID: 25535344 DOI: 10.1073/pnas.1422656112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The vacuole is the most prominent compartment in plant cells and is important for ion and protein storage. In our effort to search for key regulators in the plant vacuole sorting pathway, ribosomal large subunit 4 (rpl4d) was identified as a translational mutant defective in both vacuole trafficking and normal development. Polysome profiling of the rpl4d mutant showed reduction in polysome-bound mRNA compared with wild-type, but no significant change in the general mRNA distribution pattern. Ribsomal profiling data indicated that genes in the lipid metabolism pathways were translationally down-regulated in the rpl4d mutant. Live imaging studies by Nile red staining suggested that both polar and nonpolar lipid accumulation was reduced in meristem tissues of rpl4d mutants. Pharmacological evidence showed that sterol and sphingolipid biosynthetic inhibitors can phenocopy the defects of the rpl4d mutant, including an altered vacuole trafficking pattern. Genetic evidence from lipid biosynthetic mutants indicates that alteration in the metabolism of either sterol or sphingolipid biosynthesis resulted in vacuole trafficking defects, similar to the rpl4d mutant. Tissue-specific complementation with key enzymes from lipid biosynthesis pathways can partially rescue both vacuole trafficking and auxin-related developmental defects in the rpl4d mutant. These results indicate that lipid metabolism modulates auxin-mediated tissue differentiation and endomembrane trafficking pathways downstream of ribosomal protein function.
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197
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Zhao Q, Wu Y, Gao L, Ma J, Li CY, Xiang CB. Sulfur nutrient availability regulates root elongation by affecting root indole-3-acetic acid levels and the stem cell niche. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2014; 56:1151-63. [PMID: 24831283 DOI: 10.1111/jipb.12217] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 05/14/2014] [Indexed: 05/20/2023]
Abstract
Sulfur is an essential macronutrient for plants with numerous biological functions. However, the influence of sulfur nutrient availability on the regulation of root development remains largely unknown. Here, we report the response of Arabidopsis thaliana L. root development and growth to different levels of sulfate, demonstrating that low sulfate levels promote the primary root elongation. By using various reporter lines, we examined in vivo IAA level and distribution, cell division, and root meristem in response to different sulfate levels. Meanwhile the dynamic changes of in vivo cysteine, glutathione, and IAA levels were measured. Root cysteine, glutathione, and IAA levels are positively correlated with external sulfate levels in the physiological range, which eventually affect root system architecture. Low sulfate levels also downregulate the genes involved in auxin biosynthesis and transport, and elevate the accumulation of PLT1 and PLT2. This study suggests that sulfate level affects the primary root elongation by regulating the endogenous auxin level and root stem cell niche maintenance.
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Affiliation(s)
- Qing Zhao
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
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198
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Sanz L, Fernández-Marcos M, Modrego A, Lewis DR, Muday GK, Pollmann S, Dueñas M, Santos-Buelga C, Lorenzo O. Nitric oxide plays a role in stem cell niche homeostasis through its interaction with auxin. PLANT PHYSIOLOGY 2014; 166:1972-84. [PMID: 25315603 PMCID: PMC4256006 DOI: 10.1104/pp.114.247445] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 10/09/2014] [Indexed: 05/18/2023]
Abstract
Nitric oxide (NO) is a unique reactive nitrogen molecule with an array of signaling functions that modulates plant developmental processes and stress responses. To explore the mechanisms by which NO modulates root development, we used a pharmacological approach and NO-deficient mutants to unravel the role of NO in establishing auxin distribution patterns necessary for stem cell niche homeostasis. Using the NO synthase inhibitor and Arabidopsis (Arabidopsis thaliana) NO biosynthesis mutants (nitric oxide-associated1 [noa1], nitrate reductase1 [nia1] and nia2, and nia1 nia2 noa1), we show that depletion of NO in noa1 reduces primary root elongation and increases flavonol accumulation consistent with elevated reactive oxygen species levels. The elevated flavonols are required for the growth effect, because the transparent testa4 mutation reverses the noa1 mutant root elongation phenotype. In addition, noa1 and nia1 nia2 noa1 NO-deficient mutant roots display small root meristems with abnormal divisions. Concomitantly, auxin biosynthesis, transport, and signaling are perturbed. We further show that NO accumulates in cortex/endodermis stem cells and their precursor cells. In endodermal and cortical cells, the noa1 mutant acts synergistically to the effect of the wuschel-related homeobox5 mutation on the proximal meristem, suggesting that NO could play an important role in regulating stem cell decisions, which has been reported in animals.
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Affiliation(s)
- Luis Sanz
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - María Fernández-Marcos
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - Abelardo Modrego
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - Daniel R Lewis
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - Gloria K Muday
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - Stephan Pollmann
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - Montserrat Dueñas
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - Celestino Santos-Buelga
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
| | - Oscar Lorenzo
- Departamento de Fisiología Vegetal, Instituto Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain (L.S., M.F.-M., A.M., O.L.);Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106 (D.R.L., G.K.M.);Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28223 Pozuelo de Alarcón, Madrid, Spain (S.P.); andGrupo de Investigación en Polifenoles, Unidad de Nutrición y Bromatología, Universidad de Salamanca, 37007 Salamanca, Spain (M.D., C.S.-B.)
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199
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Zhu T, Moschou PN, Alvarez JM, Sohlberg JJ, von Arnold S. Wuschel-related homeobox 8/9 is important for proper embryo patterning in the gymnosperm Norway spruce. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6543-52. [PMID: 25205582 PMCID: PMC4246185 DOI: 10.1093/jxb/eru371] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Proper embryo development is crucial as that is when the primary body axes are established. In Arabidopsis, AtWOX8 and AtWOX9, members of the Wuschel-related homeobox (WOX) gene family, are critical for embryo development. In Norway spruce, PaWOX8/9, which is expressed in embryos, is the homologue of AtWOX8 and AtWOX9. In this work, it is shown that the transcript abundance of PaWOX8/9 is high during early and late embryogeny and that it decreases when the maturation phase starts. To address the function of PaWOX8/9 during embryo development, RNAi lines were established to down-regulate the transcript level of PaWOX8/9, using both constitutive and inducible promoters. Embryos in the PaWOX8/9 RNAi lines show an aberrant morphology caused by disturbed orientation of the cell division plane at the basal part of the embryonal mass during early and late embryogeny. In addition, the transcript level of several key cell-cycle-regulating genes, for example, PaE2FAB-like and PaCYCLIN B-like, are affected in the PaWOX8/9 RNAi lines. Taken together, our results suggest that PaWOX8/9 may perform an evolutionarily conserved function as a regulator of the establishment of the apical-basal embryo pattern.
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Affiliation(s)
- Tianqing Zhu
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center of Plant Biology in Uppsala, PO-Box 7080, SE-75007 Uppsala, Sweden
| | - Panagiotis N Moschou
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center of Plant Biology in Uppsala, PO-Box 7080, SE-75007 Uppsala, Sweden
| | - José M Alvarez
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center of Plant Biology in Uppsala, PO-Box 7080, SE-75007 Uppsala, Sweden
| | - Joel J Sohlberg
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center of Plant Biology in Uppsala, PO-Box 7080, SE-75007 Uppsala, Sweden
| | - Sara von Arnold
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center of Plant Biology in Uppsala, PO-Box 7080, SE-75007 Uppsala, Sweden
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200
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Schaller GE, Street IH, Kieber JJ. Cytokinin and the cell cycle. CURRENT OPINION IN PLANT BIOLOGY 2014; 21:7-15. [PMID: 24994531 DOI: 10.1016/j.pbi.2014.05.015] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 05/22/2014] [Accepted: 05/24/2014] [Indexed: 05/22/2023]
Abstract
The phytohormone cytokinin influences many aspects of plant growth and development, including a prominent role in the regulation of cell proliferation. How the cytokinin response pathway integrates into the machinery regulating progression through the cell cycle is only beginning to be appreciated. Cytokinin is generally considered to promote mitotic cell division in the shoot, but differentiation and transition to the endocycle in the root. Here we consider recent data on the inputs by which cytokinins positively and negatively regulate transitions through the cell cycle. Cytokinin positively regulates cell division and also serves a key role in establishing organization within shoot stem cell centers. Both auxin-dependent and auxin-independent mechanisms have been uncovered by which cytokinin stimulates the endocycle in roots. We conclude with a model that reconciles the opposing effects of cytokinin on shoot and root cell division.
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Affiliation(s)
- G Eric Schaller
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755, USA.
| | - Ian H Street
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755, USA
| | - Joseph J Kieber
- University of North Carolina, Biology Department, Chapel Hill, NC 27599, USA.
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