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Argueso CT, Kieber JJ. Cytokinin: From autoclaved DNA to two-component signaling. THE PLANT CELL 2024; 36:1429-1450. [PMID: 38163638 PMCID: PMC11062471 DOI: 10.1093/plcell/koad327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 01/03/2024]
Abstract
Since its first identification in the 1950s as a regulator of cell division, cytokinin has been linked to many physiological processes in plants, spanning growth and development and various responses to the environment. Studies from the last two and one-half decades have revealed the pathways underlying the biosynthesis and metabolism of cytokinin and have elucidated the mechanisms of its perception and signaling, which reflects an ancient signaling system evolved from two-component elements in bacteria. Mutants in the genes encoding elements involved in these processes have helped refine our understanding of cytokinin functions in plants. Further, recent advances have provided insight into the mechanisms of intracellular and long-distance cytokinin transport and the identification of several proteins that operate downstream of cytokinin signaling. Here, we review these processes through a historical lens, providing an overview of cytokinin metabolism, transport, signaling, and functions in higher plants.
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Affiliation(s)
- Cristiana T Argueso
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Joseph J Kieber
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
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2
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Wang Y, Qin M, Zhang G, Lu J, Zhang C, Ma N, Sun X, Gao J. Transcription factor RhRAP2.4L orchestrates cell proliferation and expansion to control petal size in rose. PLANT PHYSIOLOGY 2024; 194:2338-2353. [PMID: 38084893 DOI: 10.1093/plphys/kiad657] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 11/09/2023] [Indexed: 04/02/2024]
Abstract
Maintaining proper flower size is vital for plant reproduction and adaption to the environment. Petal size is determined by spatiotemporally regulated cell proliferation and expansion. However, the mechanisms underlying the orchestration of cell proliferation and expansion during petal growth remains elusive. Here, we determined that the transition from cell proliferation to expansion involves a series of distinct and overlapping processes during rose (Rosa hybrida) petal growth. Changes in cytokinin content were associated with the transition from cell proliferation to expansion during petal growth. RNA sequencing identified the AP2/ERF transcription factor gene RELATED TO AP2 4-LIKE (RhRAP2.4L), whose expression pattern positively associated with cytokinin levels during rose petal development. Silencing RhRAP2.4L promoted the transition from cell proliferation to expansion and decreased petal size. RhRAP2.4L regulates cell proliferation by directly repressing the expression of KIP RELATED PROTEIN 2 (RhKRP2), encoding a cell cycle inhibitor. In addition, we also identified BIG PETALub (RhBPEub) as another direct target gene of RhRAP2.4L. Silencing RhBPEub decreased cell size, leading to reduced petal size. Furthermore, the cytokinin signaling protein ARABIDOPSIS RESPONSE REGULATOR 14 (RhARR14) activated RhRAP2.4L expression to inhibit the transition from cell proliferation to expansion, thereby regulating petal size. Our results demonstrate that RhRAP2.4L performs dual functions in orchestrating cell proliferation and expansion during petal growth.
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Affiliation(s)
- Yaru Wang
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Meizhu Qin
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Guifang Zhang
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Jingyun Lu
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Chengkun Zhang
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Nan Ma
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Xiaoming Sun
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Junping Gao
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China
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Park J, Lee S, Park G, Cho H, Choi D, Umeda M, Choi Y, Hwang D, Hwang I. CYTOKININ-RESPONSIVE GROWTH REGULATOR regulates cell expansion and cytokinin-mediated cell cycle progression. PLANT PHYSIOLOGY 2021; 186:1734-1746. [PMID: 33909905 PMCID: PMC8260111 DOI: 10.1093/plphys/kiab180] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 03/31/2021] [Indexed: 05/23/2023]
Abstract
The cytokinin (CK) phytohormones have long been known to activate cell proliferation in plants. However, how CKs regulate cell division and cell expansion remains unclear. Here, we reveal that a basic helix-loop-helix transcription factor, CYTOKININ-RESPONSIVE GROWTH REGULATOR (CKG), mediates CK-dependent regulation of cell expansion and cell cycle progression in Arabidopsis thaliana. The overexpression of CKG increased cell size in a ploidy-independent manner and promoted entry into the S phase of the cell cycle, especially at the seedling stage. Furthermore, CKG enhanced organ growth in a pleiotropic fashion, from embryogenesis to reproductive stages, particularly of cotyledons. In contrast, ckg loss-of-function mutants exhibited smaller cotyledons. CKG mainly regulates the expression of genes involved in the regulation of the cell cycle including WEE1. We propose that CKG provides a regulatory module that connects cell cycle progression and organ growth to CK responses.
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Affiliation(s)
- Joonghyuk Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Seungchul Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Geuntae Park
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Hyunwoo Cho
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Daeseok Choi
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Masaaki Umeda
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Takayama 8916-5, Ikoma, Nara 630-0192, Japan
| | - Yeonhee Choi
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Daehee Hwang
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Ildoo Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
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Luo Y, Liu X, Li W. Exogenously-supplied trehalose inhibits the growth of wheat seedlings under high temperature by affecting plant hormone levels and cell cycle processes. PLANT SIGNALING & BEHAVIOR 2021; 16:1907043. [PMID: 33960273 PMCID: PMC8143245 DOI: 10.1080/15592324.2021.1907043] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 05/27/2023]
Abstract
High temperature reduces the yield of crops, and exogenous trehalose can improve the stress resistance of plants. However, the mechanism by which trehalose causes phenotypic changes in plants is still unknown. Here we investigated the effects of exogenously supplied trehalose (1.5 mM) during high-temperature stress and subsequent recovery on plant hormones and cell cycle in wheat seedlings. Our results showed that after high-temperature stress, exogenously supplied trehalose reduced the root length, vertical height, leaf area, and leaf length of wheat seedlings, thereby reducing their growth. However, the content of hormones, such as abscisic acid, auxin (IAA), gibberellin (GA3), and cytokinin in seedlings pretreated with trehalose and high-temperature stress was lower than that under high-temperature stress alone. Our further experiments showed that the levels of these hormones were affected by genes involved in hormone biosynthesis and decomposition pathways in trehalose-pretreated seedlings. Compared with control plants, the activity of IAA oxidase is also higher. In addition, exogenous trehalose decreased the transcriptional levels of CycD2 and CDC2 (two genes regulating cell cycle progression) under heat stress, and reduced the activity of vacuolar invertase after recovery from heat stress, thereby shortening the cell length. These results indicate that trehalose inhibits wheat growth at high temperature by affecting plant hormone levels and the cell cycle process.AbbreviationsABA, abscisic acid; CDK, cyclin-dependent kinase; CycD, D-type cyclins; GA3, gibberellin; IAA, auxin; KRP, KIP-related protein; T6P, trehalsoe-6-phosphate; VIN, vacuolar invertase.
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Affiliation(s)
- Yin Luo
- Instruments Sharing Platform of School of Life Sciences, East China Normal University, Shanghai, China
| | - Xueying Liu
- Instruments Sharing Platform of School of Life Sciences, East China Normal University, Shanghai, China
| | - Weiqiang Li
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China
- Stress Adaptation Research Unit, RIKEN Center for Sustainable Resource Science, Yokohama, Japan
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De la Fuente IM, Martínez L, Carrasco-Pujante J, Fedetz M, López JI, Malaina I. Self-Organization and Information Processing: From Basic Enzymatic Activities to Complex Adaptive Cellular Behavior. Front Genet 2021; 12:644615. [PMID: 34093645 PMCID: PMC8176287 DOI: 10.3389/fgene.2021.644615] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/16/2021] [Indexed: 11/13/2022] Open
Abstract
One of the main aims of current biology is to understand the origin of the molecular organization that underlies the complex dynamic architecture of cellular life. Here, we present an overview of the main sources of biomolecular order and complexity spanning from the most elementary levels of molecular activity to the emergence of cellular systemic behaviors. First, we have addressed the dissipative self-organization, the principal source of molecular order in the cell. Intensive studies over the last four decades have demonstrated that self-organization is central to understand enzyme activity under cellular conditions, functional coordination between enzymatic reactions, the emergence of dissipative metabolic networks (DMN), and molecular rhythms. The second fundamental source of order is molecular information processing. Studies on effective connectivity based on transfer entropy (TE) have made possible the quantification in bits of biomolecular information flows in DMN. This information processing enables efficient self-regulatory control of metabolism. As a consequence of both main sources of order, systemic functional structures emerge in the cell; in fact, quantitative analyses with DMN have revealed that the basic units of life display a global enzymatic structure that seems to be an essential characteristic of the systemic functional metabolism. This global metabolic structure has been verified experimentally in both prokaryotic and eukaryotic cells. Here, we also discuss how the study of systemic DMN, using Artificial Intelligence and advanced tools of Statistic Mechanics, has shown the emergence of Hopfield-like dynamics characterized by exhibiting associative memory. We have recently confirmed this thesis by testing associative conditioning behavior in individual amoeba cells. In these Pavlovian-like experiments, several hundreds of cells could learn new systemic migratory behaviors and remember them over long periods relative to their cell cycle, forgetting them later. Such associative process seems to correspond to an epigenetic memory. The cellular capacity of learning new adaptive systemic behaviors represents a fundamental evolutionary mechanism for cell adaptation.
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Affiliation(s)
- Ildefonso M. De la Fuente
- Department of Nutrition, CEBAS-CSIC Institute, Murcia, Spain
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Luis Martínez
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
- Basque Center of Applied Mathematics (BCAM), Bilbao, Spain
| | - Jose Carrasco-Pujante
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Maria Fedetz
- Department of Cell Biology and Immunology, Institute of Parasitology and Biomedicine “López-Neyra”, CSIC, Granada, Spain
| | - José I. López
- Department of Pathology, Cruces University Hospital, Biocruces-Bizkaia Health Research Institute, Barakaldo, Spain
| | - Iker Malaina
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
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Skalák J, Vercruyssen L, Claeys H, Hradilová J, Černý M, Novák O, Plačková L, Saiz-Fernández I, Skaláková P, Coppens F, Dhondt S, Koukalová Š, Zouhar J, Inzé D, Brzobohatý B. Multifaceted activity of cytokinin in leaf development shapes its size and structure in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:805-824. [PMID: 30748050 DOI: 10.1111/tpj.14285] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/05/2019] [Accepted: 01/10/2019] [Indexed: 05/20/2023]
Abstract
The phytohormone cytokinin has been shown to affect many aspects of plant development ranging from the regulation of the shoot apical meristem to leaf senescence. However, some studies have reported contradictory effects of cytokinin on leaf physiology. Therefore cytokinin treatments cause both chlorosis and increased greening and both lead to decrease or increase in cell size. To elucidate this multifaceted role of cytokinin in leaf development, we have employed a system of temporal controls over the cytokinin pool and investigated the consequences of modulated cytokinin levels in the third leaf of Arabidopsis. We show that, at the cell proliferation phase, cytokinin is needed to maintain cell proliferation by blocking the transition to cell expansion and the onset of photosynthesis. Transcriptome profiling revealed regulation by cytokinin of a gene suite previously shown to affect cell proliferation and expansion and thereby a molecular mechanism by which cytokinin modulates a molecular network underlying the cellular responses. During the cell expansion phase, cytokinin stimulates cell expansion and differentiation. Consequently, a cytokinin excess at the cell expansion phase results in an increased leaf and rosette size fueled by higher cell expansion rate, yielding higher shoot biomass. Proteome profiling revealed the stimulation of primary metabolism by cytokinin, in line with an increased sugar content that is expected to increase turgor pressure, representing the driving force of cell expansion. Therefore, the developmental timing of cytokinin content fluctuations, together with a tight control of primary metabolism, is a key factor mediating transitions from cell proliferation to cell expansion in leaves.
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Affiliation(s)
- Jan Skalák
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
| | - Liesbeth Vercruyssen
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Hannes Claeys
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Jana Hradilová
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
| | - Martin Černý
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators, The Czech Academy of Sciences, Institute of Experimental Botany & Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Lenka Plačková
- Laboratory of Growth Regulators, The Czech Academy of Sciences, Institute of Experimental Botany & Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Iñigo Saiz-Fernández
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
| | - Patricie Skaláková
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
| | - Frederik Coppens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Stijn Dhondt
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Šárka Koukalová
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
- CEITEC - Central European Institute of Technology, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
| | - Jan Zouhar
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
- CEITEC - Central European Institute of Technology, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Břetislav Brzobohatý
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
- CEITEC - Central European Institute of Technology, Mendel University in Brno, Zemědělská 1, CZ-61300, Brno, Czech Republic
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-61265, Brno, Czech Republic
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Ćosić T, Raspor M, Savić J, Cingel A, Matekalo D, Zdravković-Korać S, Ninković S. Expression profiles of organogenesis-related genes over the time course of one-step de novo shoot organogenesis from intact seedlings of kohlrabi. JOURNAL OF PLANT PHYSIOLOGY 2019; 232:257-269. [PMID: 30537612 DOI: 10.1016/j.jplph.2018.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/30/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
Kohlrabi (Brassica oleracea var. gongylodes) is an important vegetable crop that is able to undergo shoot regeneration in culture from intact seedlings in a single-step regeneration process, using cytokinin as the only plant growth regulator. In this work, we present the expression profiles of seven organogenesis-related genes over the time course of shoot regeneration from intact seedlings of kohlrabi cv. Vienna Purple on shoot regeneration media containing trans-zeatin, cis-zeatin, benzyl adenine or thidiazuron. Two auxin transporter genes - PIN3 and PIN4, a cytokinin response regulator - ARR5, two shoot apical meristem-related transcription factors - CUC1 and RGD3, and two cell cycle-related genes - CDKB2;1 and CYCB2;4 - displayed bimodal expression patterns on most cytokinin-containing media when their expression levels were normalized against control plants grown on hormone-free media. The first expression peak corresponded to direct upregulation by cytokinin from the growth media, and the second one reflected transcriptional events related to callus formation and/or acquisition of organogenic competence, corresponding to the shoot regeneration phases that have already been characterized in Arabidopsis thaliana. We demonstrate that the genes involved in the two-step shoot regeneration of Arabidopsis display their expected expression profiles during the single-step shoot regeneration of its close phylogenetic relative kohlrabi confirming the universality of their roles in the distinct phases of the regeneration process in Brassicaceae. The results presented here represent a first step towards genetic characterization of the morphogenetic processes in this important crop species.
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Affiliation(s)
- Tatjana Ćosić
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Martin Raspor
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Jelena Savić
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Aleksandar Cingel
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Dragana Matekalo
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Snežana Zdravković-Korać
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Slavica Ninković
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
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8
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Ren K, Hayat S, Qi X, Liu T, Cheng Z. The garlic allelochemical DADS influences cucumber root growth involved in regulating hormone levels and modulating cell cycling. JOURNAL OF PLANT PHYSIOLOGY 2018; 230:51-60. [PMID: 30170241 DOI: 10.1016/j.jplph.2018.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 08/12/2018] [Accepted: 08/12/2018] [Indexed: 06/08/2023]
Abstract
Most allelochemicals are phytotoxic to the receiver plants and may influence the cell micro- and ultrastructure, cell division, phytohormone levels, and ultimately growth. In order to understand the allelopathic potential of garlic, the effects of its main bioactive allelochemical diallyl disulfide (DADS), experiments were carried out to observe the seed germination, root growth, and developmental responses in cucumber seedlings treated with various concentrations of DADS. The obtained data suggested active influence of DADS on cucumber root growth and development. Significant responses were observed in early root growth and elongation, mitotic cell division and elongation, and root architecture modulation. The effect, however, was dose dependent, and lower concentrations of DADS proved to be promotional whereas higher concentrations of DADS inhibited cucumber root growth and development. Relative root elongation (RRE) revealed that DADS could increase growth of cucumber roots in the early developmental days. Moreover, DADS application significantly influenced mitosis-related gene expression. Observed genes CYCA and CDKB were initially downregulated in the first 24 h but significantly upregulated after 48 h, while gene CDKA was upregulated in the first 24 h. Similarly, DADS application significantly altered primary plant hormones, such as IAA, ABA, GA3, and ZR, in the cucumber roots. Taken together, low concentrations of DADS treatment could promote cucumber root growth and induce main root elongation by upregulating CDKA and CDKB gene expression and regulating hormone balance in root. The current findings offer insight into the allelopathic potential of garlic allelochemical DADS and can be considered vital for establishing plant allelopathic studies.
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Affiliation(s)
- Kaili Ren
- College of Horticulture, Northwest Agriculture and Forestry University, Yangling, China
| | - Sikandar Hayat
- College of Horticulture, Northwest Agriculture and Forestry University, Yangling, China
| | - Xiaofang Qi
- College of Horticulture, Northwest Agriculture and Forestry University, Yangling, China
| | - Tao Liu
- College of Horticulture, Northwest Agriculture and Forestry University, Yangling, China
| | - Zhihui Cheng
- College of Horticulture, Northwest Agriculture and Forestry University, Yangling, China.
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RNA-seq Analysis Reveals Gene Expression Profiling of Female Fertile and Sterile Ovules of PinusTabulaeformis Carr. during Free Nuclear Mitosis of the Female Gametophyte. Int J Mol Sci 2018; 19:ijms19082246. [PMID: 30071597 PMCID: PMC6122031 DOI: 10.3390/ijms19082246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/22/2018] [Accepted: 07/26/2018] [Indexed: 01/08/2023] Open
Abstract
The development of the female gametophyte (FG) is one of the key processes of life cycle alteration between the haploid gametophyte and the diploid sporophytes in plants and it is required for successful seed development after fertilization. It is well demonstrated that free nuclear mitosis (FNM) of FG is crucial for the development of the ovule. However, studies of the molecular mechanism of ovule and FG development focused mainly on angiosperms, such as Arabidopsis thaliana and further investigation of gymnosperms remains to be completed. Here, Illumina sequencing of six transcriptomic libraries obtained from developing and abortive ovules at different stages during free nuclear mitosis of magagametophyte (FNMM) was used to acquire transcriptome data and gene expression profiles of Pinus tabulaeformis. Six cDNA libraries generated a total of 71.0 million high-quality clean reads that aligned with 63,449 unigenes and the comparison between developing and abortive ovules identified 7174 differentially expressed genes (DEGs). From the functional annotation results, DEGs involved in the cell cycle and phytohormone regulation were highlighted to reveal their biological importance in ovule development. Furthermore, validation of DEGs from the phytohormone signal transduction pathway was performed using quantitative real-time PCR analysis, revealing the dynamics of transcriptional networks and potential key components in the regulation of FG development in P. tabulaeformis were identified. These findings provide new insights into the regulatory mechanisms of ovule development in woody gymnosperms.
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Panda BB, Sekhar S, Dash SK, Behera L, Shaw BP. Biochemical and molecular characterisation of exogenous cytokinin application on grain filling in rice. BMC PLANT BIOLOGY 2018; 18:89. [PMID: 29783938 PMCID: PMC5963110 DOI: 10.1186/s12870-018-1279-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 04/03/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND Poor filling of grains in the basal spikelets of large size panicles bearing numerous spikelets has been a major limitation in attempts to increase the rice production to feed the world's increasing population. Considering that biotechnological intervention could play important role in overcoming this limitation, the role of cytokinin in grain filling was investigated based on the information on cell proliferating potential of the hormone and reports of its high accumulation in immature seeds. RESULTS A comparative study considering two rice varieties differing in panicle compactness, lax-panicle Upahar and compact-panicle OR-1918, revealed significant difference in grain filling, cytokinin oxidase (CKX) activity and expression, and expression of cell cycle regulators and cytokinin signaling components between the basal and apical spikelets of OR-1918, but not of Upahar. Exogenous application of cytokinin (6-Benzylaminopurine, BAP) to OR-1918 improved grain filling significantly, and this was accompanied by a significant decrease in expression and activity of CKX, particularly in the basal spikelets where the activity of CKX was significantly higher than that in the apical spikelets. Cytokinin application also resulted in significant increase in expression of cell cycle regulators like cyclin dependent kinases and cyclins in the basal spikelets that might be facilitating cell division in the endosperm cells by promoting G1/S phase and G2/M phase transition leading to improvement in grain filling. Expression studies of type-A response regulator (RR) component of cytokinin signaling indicated possible role of OsRR3, OsRR4 and OsRR6 as repressors of CKX expression, much needed for an increased accumulation of CK in cells. Furthermore, the observed effect of BAP might not be solely because of it, but also because of induced synthesis of trans-zeatin (tZ) and N6-(Δ2-isopentenyl)adenine (iP), as reflected from accumulation of tZR (tZ riboside) and iPR (iP riboside), and significantly enhanced expression of an isopentenyl transferase (IPT) isoform. CONCLUSION The results suggested that seed-specific overexpression of OsRR4 and OsRR6, and more importantly of IPT9 could be an effective biotechnological intervention towards improving the CK level of the developing caryopses leading to enhanced grain filling in rice cultivars bearing large panicles with numerous spikelets, and thereby increasing their yield potential.
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Albrecht T, Argueso CT. Should I fight or should I grow now? The role of cytokinins in plant growth and immunity and in the growth-defence trade-off. ANNALS OF BOTANY 2017; 119:725-735. [PMID: 27864225 PMCID: PMC5379597 DOI: 10.1093/aob/mcw211] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 06/28/2016] [Accepted: 08/31/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND Perception and activation of plant immunity require a remarkable level of signalling plasticity and control. In Arabidopsis and other plant species, constitutive defence activation leads to resistance to a broad spectrum of biotrophic pathogens, but also frequently to stunted growth and reduced seed set. Plant hormones are important integrators of the physiological responses that influence the outcome of plant-pathogen interactions. SCOPE We review the mechanisms by which the plant hormone cytokinin regulates both plant growth and response to pathogens, and how cytokinins may connect these two processes, ultimately affecting the growth trade-offs observed in plant immunity.
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Affiliation(s)
| | - Cristiana T. Argueso
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA
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De la Fuente IM. Elements of the cellular metabolic structure. Front Mol Biosci 2015; 2:16. [PMID: 25988183 PMCID: PMC4428431 DOI: 10.3389/fmolb.2015.00016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 04/12/2015] [Indexed: 12/19/2022] Open
Abstract
A large number of studies have demonstrated the existence of metabolic covalent modifications in different molecular structures, which are able to store biochemical information that is not encoded by DNA. Some of these covalent mark patterns can be transmitted across generations (epigenetic changes). Recently, the emergence of Hopfield-like attractor dynamics has been observed in self-organized enzymatic networks, which have the capacity to store functional catalytic patterns that can be correctly recovered by specific input stimuli. Hopfield-like metabolic dynamics are stable and can be maintained as a long-term biochemical memory. In addition, specific molecular information can be transferred from the functional dynamics of the metabolic networks to the enzymatic activity involved in covalent post-translational modulation, so that determined functional memory can be embedded in multiple stable molecular marks. The metabolic dynamics governed by Hopfield-type attractors (functional processes), as well as the enzymatic covalent modifications of specific molecules (structural dynamic processes) seem to represent the two stages of the dynamical memory of cellular metabolism (metabolic memory). Epigenetic processes appear to be the structural manifestation of this cellular metabolic memory. Here, a new framework for molecular information storage in the cell is presented, which is characterized by two functionally and molecularly interrelated systems: a dynamic, flexible and adaptive system (metabolic memory) and an essentially conservative system (genetic memory). The molecular information of both systems seems to coordinate the physiological development of the whole cell.
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Affiliation(s)
- Ildefonso M. De la Fuente
- Department of Cell Biology and Immunology, Institute of Parasitology and Biomedicine “López-Neyra,” Consejo Superior de Investigaciones CientíficasGranada, Spain
- Department of Mathematics, University of the Basque Country, UPV/Euskal Herriko UnibertsitateaLeioa, Spain
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De la Fuente IM, Cortés JM, Valero E, Desroches M, Rodrigues S, Malaina I, Martínez L. On the dynamics of the adenylate energy system: homeorhesis vs homeostasis. PLoS One 2014; 9:e108676. [PMID: 25303477 PMCID: PMC4193753 DOI: 10.1371/journal.pone.0108676] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 09/03/2014] [Indexed: 11/20/2022] Open
Abstract
Biochemical energy is the fundamental element that maintains both the adequate turnover of the biomolecular structures and the functional metabolic viability of unicellular organisms. The levels of ATP, ADP and AMP reflect roughly the energetic status of the cell, and a precise ratio relating them was proposed by Atkinson as the adenylate energy charge (AEC). Under growth-phase conditions, cells maintain the AEC within narrow physiological values, despite extremely large fluctuations in the adenine nucleotides concentration. Intensive experimental studies have shown that these AEC values are preserved in a wide variety of organisms, both eukaryotes and prokaryotes. Here, to understand some of the functional elements involved in the cellular energy status, we present a computational model conformed by some key essential parts of the adenylate energy system. Specifically, we have considered (I) the main synthesis process of ATP from ADP, (II) the main catalyzed phosphotransfer reaction for interconversion of ATP, ADP and AMP, (III) the enzymatic hydrolysis of ATP yielding ADP, and (IV) the enzymatic hydrolysis of ATP providing AMP. This leads to a dynamic metabolic model (with the form of a delayed differential system) in which the enzymatic rate equations and all the physiological kinetic parameters have been explicitly considered and experimentally tested in vitro. Our central hypothesis is that cells are characterized by changing energy dynamics (homeorhesis). The results show that the AEC presents stable transitions between steady states and periodic oscillations and, in agreement with experimental data these oscillations range within the narrow AEC window. Furthermore, the model shows sustained oscillations in the Gibbs free energy and in the total nucleotide pool. The present study provides a step forward towards the understanding of the fundamental principles and quantitative laws governing the adenylate energy system, which is a fundamental element for unveiling the dynamics of cellular life.
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Affiliation(s)
- Ildefonso M. De la Fuente
- Institute of Parasitology and Biomedicine “López-Neyra”, CSIC, Granada, Spain
- Department of Mathematics, University of the Basque Country UPV/EHU, Leioa, Spain
- Unit of Biophysics (CSIC, UPV/EHU), and Department of Biochemistry and Molecular Biology University of the Basque Country, Bilbao, Spain
- Biocruces Health Research Institute, Hospital Universitario de Cruces, Barakaldo, Spain
| | - Jesús M. Cortés
- Biocruces Health Research Institute, Hospital Universitario de Cruces, Barakaldo, Spain
- Ikerbasque: The Basque Foundation for Science, Bilbao, Basque Country, Spain
| | - Edelmira Valero
- Department of Physical Chemistry, School of Industrial Engineering, University of Castilla-La Mancha, Albacete, Spain
| | | | - Serafim Rodrigues
- School of Computing and Mathematics, University of Plymouth, Plymouth, United Kingdom
| | - Iker Malaina
- Biocruces Health Research Institute, Hospital Universitario de Cruces, Barakaldo, Spain
- Department of Physiology, University of the Basque Country UPV/EHU, Bilbao, Spain
| | - Luis Martínez
- Department of Mathematics, University of the Basque Country UPV/EHU, Leioa, Spain
- Biocruces Health Research Institute, Hospital Universitario de Cruces, Barakaldo, Spain
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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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Lu Y, Tarkowská D, Turečková V, Luo T, Xin Y, Li J, Wang Q, Jiao N, Strnad M, Xu J. Antagonistic roles of abscisic acid and cytokinin during response to nitrogen depletion in oleaginous microalga Nannochloropsis oceanica expand the evolutionary breadth of phytohormone function. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:52-68. [PMID: 25041627 DOI: 10.1111/tpj.12615] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 07/06/2014] [Accepted: 07/07/2014] [Indexed: 05/03/2023]
Abstract
The origin of phytohormones is poorly understood, and their physiological roles in microalgae remain elusive. Genome comparison of photosynthetic autotrophic eukaryotes has revealed that the biosynthetic pathways of abscisic acid (ABA) and cytokinins (CKs) emerged in unicellular algae. While ABA and CK degradation mechanisms emerged broadly in algal lineages, complete vascular plant-type conjugation pathways emerged prior to the rise of Streptophyta. In microalgae, a complete set of proteins from the canonical ABA and CK sensing and signaling pathways is not essential, but individual components are present, suggesting stepwise recruitment of phytohormone signaling components. In the oleaginous eustigmatophyte Nannochloropsis oceanica IMET1, UHPLC-MS/MS detected a wide array of plant hormones, despite a phytohormone profile that is very distinct from that of flowering plants. Time-series transcriptional analysis during nitrogen depletion revealed activation of the ABA biosynthetic pathway and antagonistic transcription of CK biosynthetic genes. Correspondingly, the ABA level increases while the dominant bioactive CK forms decrease. Moreover, exogenous CKs stimulate cell-cycle progression while exogenous ABA acts as both an algal growth repressor and a positive regulator in response to stresses. The presence of such functional flowering plant-like phytohormone signaling systems in Nannochloropsis sp. suggests a much earlier origin of phytohormone biosynthesis and degradation than previously believed, and supports the presence in microalgae of as yet unknown conjugation and sensing/signaling systems that may be exploited for microalgal feedstock development.
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Affiliation(s)
- Yandu Lu
- Single Cell Center, Chinese Academy of Sciences Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
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Li J, Wu Z, Cui L, Zhang T, Guo Q, Xu J, Jia L, Lou Q, Huang S, Li Z, Chen J. Transcriptome comparison of global distinctive features between pollination and parthenocarpic fruit set reveals transcriptional phytohormone cross-talk in cucumber (Cucumis sativus L.). PLANT & CELL PHYSIOLOGY 2014; 55:1325-42. [PMID: 24733865 DOI: 10.1093/pcp/pcu051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Parthenocarpy is an important trait determining yield and quality of fruit crops. However, the understanding of the mechanisms underlying parthenocarpy induction is limited. Cucumber (Cucumis sativus L.) is abundant in parthenocarpic germplasm resources and is an excellent model organism for parthenocarpy studies. In this study, the transcriptome of cucumber fruits was studied using RNA sequencing (RNA-Seq). Differentially expressed genes (DEGs) of set fruits were compared against aborted fruits. Distinctive features of parthenocarpic and pollinated fruits were revealed by combining the analysis of the transcriptome together with cytomorphological and physiological analysis. Cell division and the transcription of cell division genes were found to be more active in parthenocarpic fruit. The study also indicated that parthenocarpic fruit set is a high sugar-consuming process which is achieved via enhanced carbohydrate degradation through transcription of genes that lead to the breakdown of carbohydrates. Furthermore, the evidence provided by this work supports a hypothesis that parthenocarpic fruit set is induced by mimicking the processes of pollination/fertilization at the transcriptional level, i.e. by performing the same transcriptional patterns of genes inducing pollination and gametophyte development as in pollinated fruit. Based on the RNA-Seq and ovary transient expression results, 14 genes were predicted as putative parthenocarpic genes. The transcription analysis of these candidate genes revealed auxin, cytokinin and gibberellin cross-talk at the transcriptional level during parthenocarpic fruit set.
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Affiliation(s)
- Ji Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, ChinaThese authors contributed equally to this work
| | - Zhe Wu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Shanxi Agricultural University, Shanxi 030801, ChinaThese authors contributed equally to this work
| | - Li Cui
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, ChinaThese authors contributed equally to this work
| | - Tinglin Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Qinwei Guo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Jian Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Li Jia
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Qunfeng Lou
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Sanwen Huang
- Key Laboratory of Horticultural Crops Genetic Improvement of Ministry of Agriculture, Sino-Dutch Joint Lab of Horticultural Genomics Technology, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhengguo Li
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 400044, China
| | - Jinfeng Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
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Schaz U, Düll B, Reinbothe C, Beck E. Influence of root-bed size on the response of tobacco to elevated CO2 as mediated by cytokinins. AOB PLANTS 2014; 6:plu010. [PMID: 24790131 PMCID: PMC4038427 DOI: 10.1093/aobpla/plu010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/06/2014] [Indexed: 05/05/2023]
Abstract
The extent of growth stimulation of C3 plants by elevated CO2 is modulated by environmental factors. Under optimized environmental conditions (high light, continuous water and nutrient supply, and others), we analysed the effect of an elevated CO2 atmosphere (700 ppm, EC) and the importance of root-bed size on the growth of tobacco. Biomass production was consistently higher under EC. However, the stimulation was overridden by root-bed volumes that restricted root growth. Maximum growth and biomass production were obtained at a root bed of 15 L at ambient and elevated CO2 concentrations. Starting with seed germination, the plants were strictly maintained under ambient or elevated CO2 until flowering. Thus, the well-known acclimation effect of growth to enhanced CO2 did not occur. The relative growth rates of EC plants exceeded those of ambient-CO2 plants only during the initial phases of germination and seedling establishment. This was sufficient for a persistently higher absolute biomass production by EC plants in non-limiting root-bed volumes. Both the size of the root bed and the CO2 concentration influenced the quantitative cytokinin patterns, particularly in the meristematic tissues of shoots, but to a smaller extent in stems, leaves and roots. In spite of the generally low cytokinin concentrations in roots, the amounts of cytokinins moving from the root to the shoot were substantially higher in high-CO2 plants. Because the cytokinin patterns of the (xylem) fluid in the stems did not match those of the shoot meristems, it is assumed that cytokinins as long-distance signals from the roots stimulate meristematic activity in the shoot apex and the sink leaves. Subsequently, the meristems are able to synthesize those phytohormones that are required for the cell cycle. Root-borne cytokinins entering the shoot appear to be one of the major control points for the integration of various environmental cues into one signal for optimized growth.
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Affiliation(s)
- Ulrike Schaz
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
- Present address: Department of Anatomy and Cell Biology, University of Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
| | - Barbara Düll
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
| | - Christiane Reinbothe
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
| | - Erwin Beck
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
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de A Bojórquez-Quintal JE, Sánchez-Cach LA, Ku-González Á, de los Santos-Briones C, de Fátima Medina-Lara M, Echevarría-Machado I, Muñoz-Sánchez JA, Teresa Hernández Sotomayor SM, Estévez MM. Differential effects of aluminum on in vitro primary root growth, nutrient content and phospholipase C activity in coffee seedlings (Coffea arabica). J Inorg Biochem 2014; 134:39-48. [PMID: 24531533 DOI: 10.1016/j.jinorgbio.2014.01.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 01/21/2014] [Accepted: 01/23/2014] [Indexed: 12/17/2022]
Abstract
Coffea arabica is a woody species that grows in acid soils, where aluminum is available and may affect growth and productivity. To determine the effect of aluminum on primary root growth of C. arabica cv. Typica, seedlings were exposed over 30 days to different concentrations of AlCl3 (0, 100, 300 and 500 μM) in vitro. The aluminum effect on primary root growth was dose-dependent: low aluminum concentrations (100 and 300 μM) stimulated primary root growth (6.98 ± 0.15 and 6.45 ± 0.17 cm, respectively) compared to the control (0 μM; 5.24 ± 0.17 cm), while high concentrations (500 μM) induced damage to the root tips and inhibition of primary root growth (2.96 ± 0.28 cm). Aluminum (100 μM) also increased the K and Ca contents around 33% and 35% in the coffee roots. It is possible that aluminum toxicity resides in its association with cell nuclei in the meristematic region of the root. Additionally, after 30 days of treatment with aluminum, two different effects could be observed on phospholipase C (PLC) activity. In shoots, aluminum concentrations ≥ 300 μM inhibited more than 50% of PLC activity. In contrast, in roots a contrasting behavior was determined: low (100 μM) and toxic concentrations (500 μM) increased the activity of PLC (100%). These results suggest the possible involvement of the phosphoinositide signal transduction pathway, with the phospholipase C enzyme participating in the beneficial and toxic effects of aluminum in plants.
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Affiliation(s)
- Jesús E de A Bojórquez-Quintal
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - Lucila A Sánchez-Cach
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - Ángela Ku-González
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - Cesar de los Santos-Briones
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - María de Fátima Medina-Lara
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - Ileana Echevarría-Machado
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - José A Muñoz-Sánchez
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - S M Teresa Hernández Sotomayor
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| | - Manuel Martínez Estévez
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 # 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico.
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Fuente IMDL, Cortes JM, Perez-Pinilla MB, Ruiz-Rodriguez V, Veguillas J. The metabolic core and catalytic switches are fundamental elements in the self-regulation of the systemic metabolic structure of cells. PLoS One 2011; 6:e27224. [PMID: 22125607 PMCID: PMC3220688 DOI: 10.1371/journal.pone.0027224] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 10/12/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a metabolic core formed by a set of enzymatic reactions which are always active under all environmental conditions, while the rest of catalytic processes are only intermittently active. The reactions of the metabolic core are essential for biomass formation and to assure optimal metabolic performance. The on-off catalytic reactions and the metabolic core are essential elements of a Systemic Metabolic Structure which seems to be a key feature common to all cellular organisms. METHODOLOGY/PRINCIPAL FINDINGS In order to investigate the functional importance of the metabolic core we have studied different catalytic patterns of a dissipative metabolic network under different external conditions. The emerging biochemical data have been analysed using information-based dynamic tools, such as Pearson's correlation and Transfer Entropy (which measures effective functionality). Our results show that a functional structure of effective connectivity emerges which is dynamical and characterized by significant variations of bio-molecular information flows. CONCLUSIONS/SIGNIFICANCE We have quantified essential aspects of the metabolic core functionality. The always active enzymatic reactions form a hub--with a high degree of effective connectivity--exhibiting a wide range of functional information values being able to act either as a source or as a sink of bio-molecular causal interactions. Likewise, we have found that the metabolic core is an essential part of an emergent functional structure characterized by catalytic modules and metabolic switches which allow critical transitions in enzymatic activity. Both, the metabolic core and the catalytic switches in which also intermittently-active enzymes are involved seem to be fundamental elements in the self-regulation of the Systemic Metabolic Structure.
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de la Fuente IM. Quantitative analysis of cellular metabolic dissipative, self-organized structures. Int J Mol Sci 2010; 11:3540-99. [PMID: 20957111 PMCID: PMC2956111 DOI: 10.3390/ijms11093540] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 09/11/2010] [Accepted: 09/12/2010] [Indexed: 11/16/2022] Open
Abstract
One of the most important goals of the postgenomic era is understanding the metabolic dynamic processes and the functional structures generated by them. Extensive studies during the last three decades have shown that the dissipative self-organization of the functional enzymatic associations, the catalytic reactions produced during the metabolite channeling, the microcompartmentalization of these metabolic processes and the emergence of dissipative networks are the fundamental elements of the dynamical organization of cell metabolism. Here we present an overview of how mathematical models can be used to address the properties of dissipative metabolic structures at different organizational levels, both for individual enzymatic associations and for enzymatic networks. Recent analyses performed with dissipative metabolic networks have shown that unicellular organisms display a singular global enzymatic structure common to all living cellular organisms, which seems to be an intrinsic property of the functional metabolism as a whole. Mathematical models firmly based on experiments and their corresponding computational approaches are needed to fully grasp the molecular mechanisms of metabolic dynamical processes. They are necessary to enable the quantitative and qualitative analysis of the cellular catalytic reactions and also to help comprehend the conditions under which the structural dynamical phenomena and biological rhythms arise. Understanding the molecular mechanisms responsible for the metabolic dissipative structures is crucial for unraveling the dynamics of cellular life.
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Affiliation(s)
- Ildefonso Martínez de la Fuente
- Institute of Parasitology and Biomedicine "López-Neyra" (CSIC), Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento s/n, 18100 Armilla (Granada), Spain; E-Mail: ; Tel.: +34-958-18-16-21
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De la Fuente IM, Vadillo F, Pérez-Samartín AL, Pérez-Pinilla MB, Bidaurrazaga J, Vera-López A. Global self-regulation of the cellular metabolic structure. PLoS One 2010; 5:e9484. [PMID: 20209156 PMCID: PMC2830472 DOI: 10.1371/journal.pone.0009484] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 02/04/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Different studies have shown that cellular enzymatic activities are able to self-organize spontaneously, forming a metabolic core of reactive processes that remain active under different growth conditions while the rest of the molecular catalytic reactions exhibit structural plasticity. This global cellular metabolic structure appears to be an intrinsic characteristic common to all cellular organisms. Recent work performed with dissipative metabolic networks has shown that the fundamental element for the spontaneous emergence of this global self-organized enzymatic structure could be the number of catalytic elements in the metabolic networks. METHODOLOGY/PRINCIPAL FINDINGS In order to investigate the factors that may affect the catalytic dynamics under a global metabolic structure characterized by the presence of metabolic cores we have studied different transitions in catalytic patterns belonging to a dissipative metabolic network. The data were analyzed using non-linear dynamics tools: power spectra, reconstructed attractors, long-term correlations, maximum Lyapunov exponent and Approximate Entropy; and we have found the emergence of self-regulation phenomena during the transitions in the metabolic activities. CONCLUSIONS/SIGNIFICANCE The analysis has also shown that the chaotic numerical series analyzed correspond to the fractional Brownian motion and they exhibit long-term correlations and low Approximate Entropy indicating a high level of predictability and information during the self-regulation of the metabolic transitions. The results illustrate some aspects of the mechanisms behind the emergence of the metabolic self-regulation processes, which may constitute an important property of the global structure of the cellular metabolism.
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The number of catalytic elements is crucial for the emergence of metabolic cores. PLoS One 2009; 4:e7510. [PMID: 19888419 PMCID: PMC2770363 DOI: 10.1371/journal.pone.0007510] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Accepted: 09/24/2009] [Indexed: 01/31/2023] Open
Abstract
Background Different studies show evidence that several unicellular organisms display a cellular metabolic structure characterized by a set of enzymes which are always in an active state (metabolic core), while the rest of the molecular catalytic reactions exhibit on-off changing states. This self-organized enzymatic configuration seems to be an intrinsic characteristic of metabolism, common to all living cellular organisms. In a recent analysis performed with dissipative metabolic networks (DMNs) we have shown that this global functional structure emerges in metabolic networks with a relatively high number of catalytic elements, under particular conditions of enzymatic covalent regulatory activity. Methodology/Principal Findings Here, to investigate the mechanism behind the emergence of this supramolecular organization of enzymes, we have performed extensive DMNs simulations (around 15,210,000 networks) taking into account the proportion of the allosterically regulated enzymes and covalent enzymes present in the networks, the variation in the number of substrate fluxes and regulatory signals per catalytic element, as well as the random selection of the catalytic elements that receive substrate fluxes from the exterior. The numerical approximations obtained show that the percentages of DMNs with metabolic cores grow with the number of catalytic elements, converging to 100% for all cases. Conclusions/Significance The results show evidence that the fundamental factor for the spontaneous emergence of this global self-organized enzymatic structure is the number of catalytic elements in the metabolic networks. Our analysis corroborates and expands on our previous studies illustrating a crucial property of the global structure of the cellular metabolism. These results also offer important insights into the mechanisms which ensure the robustness and stability of living cells.
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Werner T, Holst K, Pörs Y, Guivarc'h A, Mustroph A, Chriqui D, Grimm B, Schmülling T. Cytokinin deficiency causes distinct changes of sink and source parameters in tobacco shoots and roots. JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:2659-72. [PMID: 18515826 PMCID: PMC2486470 DOI: 10.1093/jxb/ern134] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 03/19/2008] [Accepted: 04/07/2008] [Indexed: 05/17/2023]
Abstract
Cytokinin deficiency causes pleiotropic developmental changes such as reduced shoot and increased root growth. It was investigated whether cytokinin-deficient tobacco plants, which overproduce different cytokinin oxidase/dehydrogenase enzymes, show changes in different sink and source parameters, which could be causally related to the establishment of the cytokinin deficiency syndrome. Ultrastructural analysis revealed distinct changes in differentiating shoot tissues, including an increased vacuolation and an earlier differentiation of plastids, which showed partially disorganized thylakoid structures later in development. A comparison of the ploidy levels revealed an increased population of cells with a 4C DNA content during early stages of leaf development, indicating an inhibited progression from G2 to mitosis. To compare physiological characteristics of sink leaves, source leaves and roots of wild-type and cytokinin-deficient plants, several photosynthetic parameters, content of soluble sugars, starch and adenylates, as well as activities of enzymes of carbon assimilation and dissimilation were determined. Leaves of cytokinin-deficient plants contained less chlorophyll and non-photochemical quenching of young leaves was increased. However, absorption rate, photosynthetic capacity (F(v)/F(m) and J(CO2 max)) and efficiency (Phi CO(2 app)), as well as the content of soluble sugars, were not strongly altered in source leaves, indicating that chlorophyll is not limiting for photoassimilation and suggesting that source strength did not restrict shoot growth. By contrast, shoot sink tissues showed drastically reduced contents of soluble sugars, decreased activities of vacuolar invertases, and a reduced ATP content. These results strongly support a function of cytokinin in regulating shoot sink strength and its reduction may be a cause of the altered shoot phenotype. Roots of cytokinin-deficient plants contained less sugar compared with wild-type. However, this did not negatively affect glycolysis, ATP content, or root development. It is suggested that cytokinin-mediated regulation of the sink strength differs between roots and shoots.
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Affiliation(s)
- Tomáš Werner
- Institute of Biology/Applied Genetics, Free University of Berlin, Berlin, Germany
| | - Kerstin Holst
- Institute of Biology/Applied Genetics, Free University of Berlin, Berlin, Germany
| | - Yvonne Pörs
- Institute of Biology/Plant Physiology, Humboldt University Berlin, Berlin, Germany
| | - Anne Guivarc'h
- Cytologie Expérimentale et Morphogenèse Végétale (CEMV), Université Pierre et Marie Curie, Paris, France
| | - Angelika Mustroph
- Institute of Biology/Plant Physiology, Humboldt University Berlin, Berlin, Germany
| | - Dominique Chriqui
- Cytologie Expérimentale et Morphogenèse Végétale (CEMV), Université Pierre et Marie Curie, Paris, France
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt University Berlin, Berlin, Germany
| | - Thomas Schmülling
- Institute of Biology/Applied Genetics, Free University of Berlin, Berlin, Germany
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Vandeputte O, Vereecke D, Mol A, Lenjou M, Van Bockstaele D, El Jaziri M, Baucher M. Rhodococcus fascians infection accelerates progression of tobacco BY-2 cells into mitosis through rapid changes in plant gene expression. THE NEW PHYTOLOGIST 2007; 175:140-154. [PMID: 17547674 DOI: 10.1111/j.1469-8137.2007.02062.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
* To characterize plant cell cycle activation following Rhodococcus fascians infection, bacterial impact on cell cycle progression of tobacco BY-2 cells was investigated. * S-phase-synchronized BY-2 cells were cocultivated with R. fascians and cell cycle progression was monitored by measuring mitotic index, cell cycle gene expression and flow cytometry parameters. Cell cycle alteration was further investigated by cDNA-AFLP (amplified fragment length polymorphism). * It was shown that cell cycle progression of BY-2 cells was accelerated only upon infection with bacteria whose virulence gene expression was induced by a leafy gall extract. Thirty-eight BY-2 genes showed a differential expression within 6 h post-infection. Among these, seven were previously associated with specific plant cell cycle phases (in particular S and G2/M phases). Several genes also showed a differential expression during leafy gall formation. * R. fascians-infected BY-2 cells provide a simple model to identify plant genes related to leafy gall development. R. fascians can also be regarded as a useful biotic agent to alter cell cycle progression and, thereby, gain a better understanding of cell cycle regulation in plants.
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Affiliation(s)
- Olivier Vandeputte
- Laboratoire de Biotechnologie Végétale, Université Libre de Bruxelles, rue Adrienne Bolland 8, B-6041 Gosselies, Belgium
| | - Danny Vereecke
- Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB)
| | - Adeline Mol
- Laboratoire de Biotechnologie Végétale, Université Libre de Bruxelles, rue Adrienne Bolland 8, B-6041 Gosselies, Belgium
| | - Marc Lenjou
- Laboratory of Experimental Haematology, University of Antwerp, Antwerp University Hospital, Wilrijkstraat 10, B-2650 Edegem, Belgium
| | - Dirk Van Bockstaele
- Laboratory of Experimental Haematology, University of Antwerp, Antwerp University Hospital, Wilrijkstraat 10, B-2650 Edegem, Belgium
| | - Mondher El Jaziri
- Laboratoire de Biotechnologie Végétale, Université Libre de Bruxelles, rue Adrienne Bolland 8, B-6041 Gosselies, Belgium
| | - Marie Baucher
- Laboratoire de Biotechnologie Végétale, Université Libre de Bruxelles, rue Adrienne Bolland 8, B-6041 Gosselies, Belgium
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Werner T, Köllmer I, Bartrina I, Holst K, Schmülling T. New insights into the biology of cytokinin degradation. PLANT BIOLOGY (STUTTGART, GERMANY) 2006; 8:371-81. [PMID: 16807830 DOI: 10.1055/s-2006-923928] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A survey of recent results is presented concerning the role of cytokinin degradation in plants, which is catalyzed by cytokinin oxidase/dehydrogenase (CKX) enzymes. An overview of Arabidopsis CKX gene expression suggests that their differential regulation by biotic and abiotic factors contributes significantly to functional specification. Here, we show using reporter gene and semiquantitative RT-PCR analyses regulation of individual CKX genes by cytokinin, auxin, ABA, and phosphate starvation. Partially overlapping expression domains of CKX genes and cytokinin-synthesizing IPT genes in meristematic tissues and endo-reduplicating cells lend support for a locally restricted function of cytokinin. On the other hand, their expression in vascular tissue suggests a function in controlling transported cytokinin. Recent studies led to a model for the biochemical reaction mechanism of CKX-mediated catalysis, which was refined on the basis of the three-dimensional enzyme structure. Last but not least, the developmental functions of CKX enzymes are addressed. The recent identification of the rice OSCKX2 gene as an important novel breeding tool is highlighted. Together the results corroborate the relevance of metabolic control in determining cytokinin activity.
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Affiliation(s)
- T Werner
- Institute of Biology/Applied Genetics, Free University of Berlin, Albrecht-Thaer-Weg 6, 14195 Berlin, Germany
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Hartig K, Beck E. Crosstalk between auxin, cytokinins, and sugars in the plant cell cycle. PLANT BIOLOGY (STUTTGART, GERMANY) 2006; 8:389-96. [PMID: 16807832 DOI: 10.1055/s-2006-923797] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Plant meristems are utilization sinks, in which cell division activity governs sink strength. However, the molecular mechanisms by which cell division activity and sink strength are adjusted to a plant's developmental program in its environmental setting are not well understood. Mitogenic hormonal as well as metabolic signals drive and modulate the cell cycle, but a coherent idea of how this is accomplished, is still missing. Auxin and cytokinins are known as endogenous mitogens whose concentrations and timing, however, can be externally affected. Although the sites and mechanisms of signal interaction in cell cycle control have not yet been unravelled, crosstalk of sugar and phytohormone signals could be localized to several biochemical levels. At the expression level of cell cycle control genes, like cyclins, Cdks, and others, synergistic but also antagonistic interactions could be demonstrated. Another level of crosstalk is that of signal generation or modulation. Cytokinins affect the activity of extracellular invertases and hexose-uptake carriers and thus impinge on an intracellular sugar signal. With tobacco BY-2 cells, a coordinated control of cell cycle activity at both regulatory levels could be shown. Comparison of the results obtained with the root cell-representing BY-2 cells with literature data from shoot tissues or green cell cultures of Arabidopsis and Chenopodium suggests opposed and tissue-specific regulatory patterns of mitogenic signals and signal crosstalk in root and shoot meristems.
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Affiliation(s)
- K Hartig
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany.
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