1
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Boix M, Garcia-Rodriguez A, Castillo L, Miró B, Hamilton F, Tolak S, Pérez A, Monte-Bello C, Caldana C, Henriques R. 40S Ribosomal protein S6 kinase integrates daylength perception and growth regulation in Arabidopsis thaliana. PLANT PHYSIOLOGY 2024; 195:3039-3052. [PMID: 38701056 PMCID: PMC11288760 DOI: 10.1093/plphys/kiae254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/29/2024] [Accepted: 04/09/2024] [Indexed: 05/05/2024]
Abstract
Plant growth occurs via the interconnection of cell growth and proliferation in each organ following specific developmental and environmental cues. Therefore, different photoperiods result in distinct growth patterns due to the integration of light and circadian perception with specific Carbon (C) partitioning strategies. In addition, the TARGET OF RAPAMYCIN (TOR) kinase pathway is an ancestral signaling pathway that integrates nutrient information with translational control and growth regulation. Recent findings in Arabidopsis (Arabidopsis thaliana) have shown a mutual connection between the TOR pathway and the circadian clock. However, the mechanistical network underlying this interaction is mostly unknown. Here, we show that the conserved TOR target, the 40S ribosomal protein S6 kinase (S6K) is under circadian and photoperiod regulation both at the transcriptional and post-translational level. Total S6K (S6K1 and S6K2) and TOR-dependent phosphorylated-S6K protein levels were higher during the light period and decreased at dusk especially under short day conditions. Using chemical and genetic approaches, we found that the diel pattern of S6K accumulation results from 26S proteasome-dependent degradation and is altered in mutants lacking the circadian F-box protein ZEITLUPE (ZTL), further strengthening our hypothesis that S6K could incorporate metabolic signals via TOR, which are also under circadian regulation. Moreover, under short days when C/energy levels are limiting, changes in S6K1 protein levels affected starch, sucrose and glucose accumulation and consequently impacted root and rosette growth responses. In summary, we propose that S6K1 constitutes a missing molecular link where day-length perception, nutrient availability and TOR pathway activity converge to coordinate growth responses with environmental conditions.
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Affiliation(s)
- Marc Boix
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB, 08193 Barcelona, Spain
| | - Alba Garcia-Rodriguez
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB, 08193 Barcelona, Spain
| | - Laia Castillo
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB, 08193 Barcelona, Spain
| | - Bernat Miró
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB, 08193 Barcelona, Spain
| | - Ferga Hamilton
- School of Biological, Earth and Environmental Sciences, University College Cork, North Mall, Cork T23 N73K, Ireland
- Environmental Research Institute, University College Cork, Cork T23 XE10, Ireland
| | - Sanata Tolak
- School of Biological, Earth and Environmental Sciences, University College Cork, North Mall, Cork T23 N73K, Ireland
- Environmental Research Institute, University College Cork, Cork T23 XE10, Ireland
| | - Adrián Pérez
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB, 08193 Barcelona, Spain
| | | | - Camila Caldana
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm 14476, Germany
| | - Rossana Henriques
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB, 08193 Barcelona, Spain
- School of Biological, Earth and Environmental Sciences, University College Cork, North Mall, Cork T23 N73K, Ireland
- Environmental Research Institute, University College Cork, Cork T23 XE10, Ireland
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2
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Cho H, Banf M, Shahzad Z, Van Leene J, Bossi F, Ruffel S, Bouain N, Cao P, Krouk G, De Jaeger G, Lacombe B, Brandizzi F, Rhee SY, Rouached H. ARSK1 activates TORC1 signaling to adjust growth to phosphate availability in Arabidopsis. Curr Biol 2023; 33:1778-1786.e5. [PMID: 36963384 PMCID: PMC10175222 DOI: 10.1016/j.cub.2023.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 02/12/2023] [Accepted: 03/02/2023] [Indexed: 03/26/2023]
Abstract
Nutrient sensing and signaling are essential for adjusting growth and development to available resources. Deprivation of the essential mineral phosphorus (P) inhibits root growth.1 The molecular processes that sense P limitation to trigger early root growth inhibition are not known yet. Target of rapamycin (TOR) kinase is a central regulatory hub in eukaryotes to adapt growth to internal and external nutritional cues.2,3 How nutritional signals are transduced to TOR to control plant growth remains unclear. Here, we identify Arabidopsis-root-specific kinase 1 (ARSK1), which attenuates initial root growth inhibition in response to P limitation. We demonstrate that ARSK1 phosphorylates and stabilizes the regulatory-associated protein of TOR 1B (RAPTOR1B), a component of the TOR complex 1, to adjust root growth to P availability. These findings uncover signaling components acting upstream of TOR to balance growth to P availability.
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Affiliation(s)
- Huikyong Cho
- The Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA; Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
| | - Michael Banf
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Zaigham Shahzad
- Department of Life Sciences, Lahore University of Management Sciences, Lahore 54792, Pakistan
| | - Jelle Van Leene
- Ghent University, Department of Plant Biotechnology and Bioinformatics, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Flavia Bossi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Sandrine Ruffel
- Institute for Plant Sciences of Montpellier, University Montpellier, CNRS, INRAE, Montpellier 34060, France
| | - Nadia Bouain
- Institute for Plant Sciences of Montpellier, University Montpellier, CNRS, INRAE, Montpellier 34060, France
| | - Pengfei Cao
- MSU DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Gabiel Krouk
- Institute for Plant Sciences of Montpellier, University Montpellier, CNRS, INRAE, Montpellier 34060, France
| | - Geert De Jaeger
- Ghent University, Department of Plant Biotechnology and Bioinformatics, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Benoit Lacombe
- Institute for Plant Sciences of Montpellier, University Montpellier, CNRS, INRAE, Montpellier 34060, France
| | - Federica Brandizzi
- MSU DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Seung Y Rhee
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
| | - Hatem Rouached
- The Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA; Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA.
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3
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Liao CY, Pu Y, Nolan TM, Montes C, Guo H, Walley JW, Yin Y, Bassham DC. Brassinosteroids modulate autophagy through phosphorylation of RAPTOR1B by the GSK3-like kinase BIN2 in Arabidopsis. Autophagy 2023; 19:1293-1310. [PMID: 36151786 PMCID: PMC10012961 DOI: 10.1080/15548627.2022.2124501] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Macroautophagy/autophagy is a conserved recycling process that maintains cellular homeostasis during environmental stress. Autophagy is negatively regulated by TOR (target of rapamycin), a nutrient-regulated protein kinase that in plants is activated by several phytohormones, leading to increased growth. However, the detailed molecular mechanisms by which TOR integrates autophagy and hormone signaling are poorly understood. Here, we show that TOR modulates brassinosteroid (BR)-regulated plant growth and stress-response pathways. Active TOR was required for full BR-mediated growth in Arabidopsis thaliana. Autophagy was constitutively up-regulated upon blocking BR biosynthesis or signaling, and down-regulated by increasing the activity of the BR pathway. BIN2 (brassinosteroid-insensitive 2) kinase, a GSK3-like kinase functioning as a negative regulator in BR signaling, directly phosphorylated RAPTOR1B (regulatory-associated protein of TOR 1B), a substrate-recruiting subunit in the TOR complex, at a conserved serine residue within a typical BIN2 phosphorylation motif. Mutation of RAPTOR1B serine 916 to alanine, to block phosphorylation by BIN2, repressed autophagy and increased phosphorylation of the TOR substrate ATG13a (autophagy-related protein 13a). By contrast, this mutation had only a limited effect on growth. We present a model in which RAPTOR1B is phosphorylated and inhibited by BIN2 when BRs are absent, activating the autophagy pathway. When BRs signal and inhibit BIN2, RAPTOR1B is thus less inhibited by BIN2 phosphorylation. This leads to increased TOR activity and ATG13a phosphorylation, and decreased autophagy activity. Our studies define a new mechanism by which coordination between BR and TOR signaling pathways helps to maintain the balance between plant growth and stress responses.
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Affiliation(s)
- Ching-Yi Liao
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Yunting Pu
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Trevor M Nolan
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Christian Montes
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, USA
| | - Hongqing Guo
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Justin W Walley
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, USA
| | - Yanhai Yin
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
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4
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Retzer K, Weckwerth W. Recent insights into metabolic and signalling events of directional root growth regulation and its implications for sustainable crop production systems. FRONTIERS IN PLANT SCIENCE 2023; 14:1154088. [PMID: 37008498 PMCID: PMC10060999 DOI: 10.3389/fpls.2023.1154088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
Roots are sensors evolved to simultaneously respond to manifold signals, which allow the plant to survive. Root growth responses, including the modulation of directional root growth, were shown to be differently regulated when the root is exposed to a combination of exogenous stimuli compared to an individual stress trigger. Several studies pointed especially to the impact of the negative phototropic response of roots, which interferes with the adaptation of directional root growth upon additional gravitropic, halotropic or mechanical triggers. This review will provide a general overview of known cellular, molecular and signalling mechanisms involved in directional root growth regulation upon exogenous stimuli. Furthermore, we summarise recent experimental approaches to dissect which root growth responses are regulated upon which individual trigger. Finally, we provide a general overview of how to implement the knowledge gained to improve plant breeding.
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Affiliation(s)
- Katarzyna Retzer
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
| | - Wolfram Weckwerth
- Department of Functional and Evolutionary Ecology, Faculty of Life Sciences, Molecular Systems Biology (MoSys), University of Vienna, Wien, Austria
- Vienna Metabolomics Center (VIME), University of Vienna, Wien, Austria
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5
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Urrea-Castellanos R, Caldana C, Henriques R. Growing at the right time: interconnecting the TOR pathway with photoperiod and circadian regulation. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7006-7015. [PMID: 35738873 PMCID: PMC9664226 DOI: 10.1093/jxb/erac279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
Plants can adjust their growth to specific times of the day and season. Different photoperiods result in distinct growth patterns, which correlate with specific carbon-partitioning strategies in source (leaves) and sink (roots) organs. Therefore, external cues such as light, day length, and temperature need to be integrated with intracellular processes controlling overall carbon availability and anabolism. The target of rapamycin (TOR) pathway is a signalling hub where environmental signals, circadian information, and metabolic processes converge to regulate plant growth. TOR complex mutants display altered patterns of root growth and starch levels. Moreover, depletion of TOR or reduction in cellular energy levels affect the pace of the clock by extending the period length, suggesting that this pathway could participate in circadian metabolic entrainment. However, this seems to be a mutual interaction, since the TOR pathway components are also under circadian regulation. These results strengthen the role of this signalling pathway as a master sensor of metabolic status, integrating day length and circadian cues to control anabolic processes in the cell, thus promoting plant growth and development. Expanding this knowledge from Arabidopsis thaliana to crops will improve our understanding of the molecular links connecting environmental perception and growth regulation under field conditions.
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Affiliation(s)
| | - Camila Caldana
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
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6
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Curative activity of KCl treatments to control citrus sour rot. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Haq SIU, Shang J, Xie H, Qiu QS. Roles of TOR signaling in nutrient deprivation and abiotic stress. JOURNAL OF PLANT PHYSIOLOGY 2022; 274:153716. [PMID: 35597106 DOI: 10.1016/j.jplph.2022.153716] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/25/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
In living organisms, nutrient, energy, and environmental stimuli sensing and signaling are considered as the most primordial regulatory networks governing growth and development. Target of Rapamycin (TOR) is a diversified Serine/Threonine protein kinase existing in all eukaryotes that regulates distinct salient growth and developmental signaling pathways. TOR signaling acts as a central hub in plants that allows a variety of nutrients, energy, hormones, and environmental stimuli to be integrated. TOR is activated by several nutrients and promotes energy-consuming processes such as cell division, protein translation, mRNA translation and ribosome biogenesis. We summarized the recent findings on the TOR function in regulating the dynamic networks of nutrients, including sugar, sulfur, nitrogen, carbon, phosphorus, potassium, and amino acids. TOR's role in abiotic stress was discussed, in which TOR orchestrating stress signaling, including heat, cold, salt, and osmotic stress, to regulate transcriptional and metabolic reprogramming, as well as growth and development. The interconnections between TOR and SnRK1 kinase were discussed in controlling nutrient deprivation and abiotic stress.
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Affiliation(s)
- Syed Inzimam Ul Haq
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China
| | - Jun Shang
- Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China; Qinghai Provincial Key Laboratory of Medicinal Plant and Animal Resources of Qinghai-Tibet Plateau, Xining, Qinghai, 810008, China
| | - Huichun Xie
- Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China; Qinghai Provincial Key Laboratory of Medicinal Plant and Animal Resources of Qinghai-Tibet Plateau, Xining, Qinghai, 810008, China
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China; Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China.
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8
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Wingler A, Henriques R. Sugars and the speed of life-Metabolic signals that determine plant growth, development and death. PHYSIOLOGIA PLANTARUM 2022; 174:e13656. [PMID: 35243645 PMCID: PMC9314607 DOI: 10.1111/ppl.13656] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 05/27/2023]
Abstract
Plant growth and development depend on the availability of carbohydrates synthesised in photosynthesis (source activity) and utilisation of these carbohydrates for growth (sink activity). External conditions, such as temperature, nutrient availability and stress, can affect source as well as sink activity. Optimal utilisation of resources is under circadian clock control. This molecular timekeeper ensures that growth responses are adjusted to different photoperiod and temperature settings by modulating starch accumulation and degradation accordingly. For example, during the night, starch degradation is required to provide sugars for growth. Under favourable growth conditions, high sugar availability stimulates growth and development, resulting in an overall accelerated life cycle of annual plants. Key signalling components include trehalose-6-phosphate (Tre6P), which reflects sucrose availability and stimulates growth and branching when the conditions are favourable. Under sink limitation, Tre6P does, however, inhibit night-time starch degradation. Tre6P interacts with Sucrose-non-fermenting1-Related Kinase1 (SnRK1), a protein kinase that inhibits growth under starvation and stress conditions and delays development (including flowering and senescence). Tre6P inhibits SnRK1 activity, but SnRK1 increases the Tre6P to sucrose ratio under favourable conditions. Alongside Tre6P, Target of Rapamycin (TOR) stimulates processes such as protein synthesis and growth when sugar availability is high. In annual plants, an accelerated life cycle results in early leaf and plant senescence, thus shortening the lifespan. While the availability of carbohydrates in the form of sucrose and other sugars also plays an important role in seasonal life cycle events (phenology) of perennial plants, the sugar signalling pathways in perennials are less well understood.
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Affiliation(s)
- Astrid Wingler
- School of Biological, Earth & Environmental Sciences and Environmental Research InstituteUniversity College Cork, Distillery FieldsCork
| | - Rossana Henriques
- School of Biological, Earth & Environmental Sciences and Environmental Research InstituteUniversity College Cork, Distillery FieldsCork
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9
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Alvarez ME, Savouré A, Szabados L. Proline metabolism as regulatory hub. TRENDS IN PLANT SCIENCE 2022; 27:39-55. [PMID: 34366236 DOI: 10.1016/j.tplants.2021.07.009] [Citation(s) in RCA: 92] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 07/01/2021] [Accepted: 07/08/2021] [Indexed: 05/21/2023]
Abstract
Proline is a multifunctional amino acid that is accumulated in high concentrations in plants under various stress conditions. Proline accumulation is intimately connected to many cellular processes, such as osmotic pressure, energy status, nutrient availability, changes in redox balance, and defenses against pathogens. Proline biosynthesis and catabolism is linked to photosynthesis and mitochondrial respiration, respectively. Proline can function as a signal, modulating gene expression and certain metabolic processes. We review important findings on proline metabolism and function of the last decade, giving a more informative picture about the function of this unusual amino acid in maintaining cellular homeostasis, modulating plant development, and promoting stress acclimation.
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Affiliation(s)
- María E Alvarez
- CIQUIBIC, CONICET, Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina.
| | - Arnould Savouré
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - László Szabados
- Institute of Plant Biology, Biological Research Centre, 6726-Szeged, Hungary.
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10
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da Silva VCH, Martins MCM, Calderan-Rodrigues MJ, Artins A, Monte Bello CC, Gupta S, Sobreira TJP, Riaño-Pachón DM, Mafra V, Caldana C. Shedding Light on the Dynamic Role of the "Target of Rapamycin" Kinase in the Fast-Growing C 4 Species Setaria viridis, a Suitable Model for Biomass Crops. FRONTIERS IN PLANT SCIENCE 2021; 12:637508. [PMID: 33927734 PMCID: PMC8078139 DOI: 10.3389/fpls.2021.637508] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
The Target of Rapamycin (TOR) kinase pathway integrates energy and nutrient availability into metabolism promoting growth in eukaryotes. The overall higher efficiency on nutrient use translated into faster growth rates in C4 grass plants led to the investigation of differential transcriptional and metabolic responses to short-term chemical TOR complex (TORC) suppression in the model Setaria viridis. In addition to previously described responses to TORC inhibition (i.e., general growth arrest, translational repression, and primary metabolism reprogramming) in Arabidopsis thaliana (C3), the magnitude of changes was smaller in S. viridis, particularly regarding nutrient use efficiency and C allocation and partitioning that promote biosynthetic growth. Besides photosynthetic differences, S. viridis and A. thaliana present several specificities that classify them into distinct lineages, which also contribute to the observed alterations mediated by TOR. Indeed, cell wall metabolism seems to be distinctly regulated according to each cell wall type, as synthesis of non-pectic polysaccharides were affected in S. viridis, whilst assembly and structure in A. thaliana. Our results indicate that the metabolic network needed to achieve faster growth seems to be less stringently controlled by TORC in S. viridis.
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Affiliation(s)
| | | | | | - Anthony Artins
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | | | - Saurabh Gupta
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam-Golm, Germany
| | | | | | - Valéria Mafra
- National Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Camila Caldana
- National Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
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11
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Zhigailov AV, Stanbekova GE, Beisenov DK, Nizkorodova AS, Polimbetova NS, Iskakov BK. Constructing the constitutively active ribosomal protein S6 kinase 2 from Arabidopsis thaliana (AtRPS6K2) and testing its activity in vitro. Vavilovskii Zhurnal Genet Selektsii 2021; 24:233-238. [PMID: 33659803 PMCID: PMC7904244 DOI: 10.18699/vj20.39-o] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Ribosomal protein S6 (RPS6) is the only phosphorylatable protein of the eukaryotic 40S ribosomal subunit. Ribosomes with phosphorylated RPS6 can selectively translate 5'TOP-(5'-terminal oligopyrimidine)-containing mRNAs that encode most proteins of the translation apparatus. The study of translational control of 5'TOP-mRNAs, which are preferentially translated when RPS6 is phosphorylated and cease to be translated when RPS6 is de-phosphorylated, is particularly important. In Arabidopsis thaliana, AtRPS6 is phosphorylated by kinase AtRPS6K2, which should in turn be phosphorylated by upper level kinases (AtPDK1 - at serine (S) 296, AtTOR - at threonine (T) 455 and S437) for full activation. We have cloned AtRPS6K2 cDNA gene and carried out in vitro mutagenesis replacing codons encoding S296, S437 and T455 by triplets of phosphomimetic glutamic acid (E). After the expression of both natural and mutated cDNAs in Escherichia coli cells, two recombinant proteins were isolated: native AtRPS6K2 and presumably constitutively active AtRPS6K2(S296E, S437E, T455E). The activity of these variants was tested in vitro. Both kinases could phosphorylate wheat (Triticum aestivum L.) TaRPS6 as part of 40S ribosomal subunits isolated from wheat embryos, though the non-mutated variant had less activity than phosphomimetic one. The ability of recombinant non-mutated kinase to phosphorylate TaRPS6 can be explained by its phosphorylation by bacterial kinases during the expression and isolation steps. The phosphomimetically mutated AtRPS6K2(S296E, S437E, T455E) can serve as a tool to investigate preferential translation of 5'TOP-mRNAs in wheat germ cell-free system, in which most of 40S ribosomal subunits have phosphorylated TaRPS6. Besides, such an approach has a biotechnological application in producing genetically modified plants with increased biomass and productivity through stimulation of cell growth and division.
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Affiliation(s)
- A V Zhigailov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Almaty, Kazakhstan
| | - G E Stanbekova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Almaty, Kazakhstan
| | - D K Beisenov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Almaty, Kazakhstan Institute of Plant Biology and Biotechnology, Almaty, Kazakhstan
| | - A S Nizkorodova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Almaty, Kazakhstan
| | - N S Polimbetova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Almaty, Kazakhstan
| | - B K Iskakov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Almaty, Kazakhstan Institute of Plant Biology and Biotechnology, Almaty, Kazakhstan
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12
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Bömer M, Pérez‐Salamó I, Florance HV, Salmon D, Dudenhoffer J, Finch P, Cinar A, Smirnoff N, Harvey A, Devoto A. Jasmonates induce Arabidopsis bioactivities selectively inhibiting the growth of breast cancer cells through CDC6 and mTOR. THE NEW PHYTOLOGIST 2021; 229:2120-2134. [PMID: 33124043 PMCID: PMC8022592 DOI: 10.1111/nph.17031] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/26/2020] [Indexed: 06/11/2023]
Abstract
Phytochemicals are used often in vitro and in vivo in cancer research. The plant hormones jasmonates (JAs) control the synthesis of specialized metabolites through complex regulatory networks. JAs possess selective cytotoxicity in mixed populations of cancer and normal cells. Here, direct incubation of leaf explants from the non-medicinal plant Arabidopsis thaliana with human breast cancer cells, selectively suppresses cancer cell growth. High-throughput LC-MS identified Arabidopsis metabolites. Protein and transcript levels of cell cycle regulators were examined in breast cancer cells. A synergistic effect by methyljasmonate (MeJA) and by compounds upregulated in the metabolome of MeJA-treated Arabidopsis leaves, on the breast cancer cell cycle, is associated with Cell Division Cycle 6 (CDC6), Cyclin-dependent kinase 2 (CDK2), Cyclins D1 and D3, indicating that key cell cycle components mediate cell viability reduction. Bioactives such as indoles, quinolines and cis-(+)-12-oxophytodienoic acid, in synergy, could act as anticancer compounds. Our work suggests a universal role for MeJA-treatment of Arabidopsis in altering the DNA replication regulator CDC6, supporting conservation, across kingdoms, of cell cycle regulation, through the crosstalk between the mechanistic target of rapamycin, mTOR and JAs. This study has important implications for the identification of metabolites with anti-cancer bioactivities in plants with no known medicinal pedigree and it will have applications in developing disease treatments.
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Affiliation(s)
- Moritz Bömer
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
- Natural Resources InstituteUniversity of GreenwichCentral AvenueChatham MaritimeME4 4TBUK
| | - Imma Pérez‐Salamó
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
| | - Hannah V. Florance
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterGeoffrey Pope Building, Stocker RoadExeterEX4 4QDUK
| | - Deborah Salmon
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterGeoffrey Pope Building, Stocker RoadExeterEX4 4QDUK
| | | | - Paul Finch
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
| | - Aycan Cinar
- Institute of Environment, Health and SocietiesBrunel University LondonKingston LaneUxbridgeUB8 3PHUK
| | - Nicholas Smirnoff
- BiosciencesCollege of Life and Environmental SciencesUniversity of ExeterGeoffrey Pope Building, Stocker RoadExeterEX4 4QDUK
| | - Amanda Harvey
- Institute of Environment, Health and SocietiesBrunel University LondonKingston LaneUxbridgeUB8 3PHUK
| | - Alessandra Devoto
- Department of Biological SciencesPlant Molecular Science and Centre of Systems and Synthetic BiologyRoyal Holloway University of LondonEghamTW20 0EXUK
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13
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Chen X, Ding Y, Yang Y, Song C, Wang B, Yang S, Guo Y, Gong Z. Protein kinases in plant responses to drought, salt, and cold stress. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:53-78. [PMID: 33399265 DOI: 10.1111/jipb.13061] [Citation(s) in RCA: 222] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 12/19/2020] [Indexed: 05/20/2023]
Abstract
Protein kinases are major players in various signal transduction pathways. Understanding the molecular mechanisms behind plant responses to biotic and abiotic stresses has become critical for developing and breeding climate-resilient crops. In this review, we summarize recent progress on understanding plant drought, salt, and cold stress responses, with a focus on signal perception and transduction by different protein kinases, especially sucrose nonfermenting1 (SNF1)-related protein kinases (SnRKs), mitogen-activated protein kinase (MAPK) cascades, calcium-dependent protein kinases (CDPKs/CPKs), and receptor-like kinases (RLKs). We also discuss future challenges in these research fields.
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Affiliation(s)
- Xuexue Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yanglin Ding
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yongqing Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Chunpeng Song
- Collaborative Innovation Center of Crop Stress Biology, Henan Province, Institute of Plant Stress Biology, Henan University, Kaifeng, 475001, China
| | - Baoshan Wang
- Key Lab of Plant Stress Research, College of Life Science, Shandong Normal University, Ji'nan, 250000, China
| | - Shuhua Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yan Guo
- 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
- Institute of Life Science and Green Development, School of Life Sciences, Hebei University, Baoding, 071001, China
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14
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Sun X, Chen H, Wang P, Chen F, Yuan L, Mi G. Low nitrogen induces root elongation via auxin-induced acid growth and auxin-regulated target of rapamycin (TOR) pathway in maize. JOURNAL OF PLANT PHYSIOLOGY 2020; 254:153281. [PMID: 32971423 DOI: 10.1016/j.jplph.2020.153281] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 09/04/2020] [Accepted: 09/04/2020] [Indexed: 05/23/2023]
Abstract
Under low nitrogen (N) supply, an important adaption of the maize root system is to promote the root elongation so as to increase N uptake from a larger soil space. The underlying physiological mechanism is largely unknown. In the present study, two maize inbred lines (Ye478 and Wu312) were used to study the possible involvement of the auxin and target of rapamycin (TOR) pathway in low-N-induced root elongation. Compared to Wu312, primary root elongation of Ye478 was more sensitive to low nitrate supply. Correspondingly, more auxin was accumulated in the root tip, and more protons were secreted, increasing the acidity of the apoplast space. On the other hand, low-N-induced root elongation was greatly reduced when shoot-to-root auxin transport was inhibited by applying N-1-naphthylphthalamic acid (NPA) at the plant base or by pruning the top leaf where auxin is mostly synthesized. Furthermore, exogenous application of TOR inhibitor also eliminated the response of root elongation under low N. The content of TOR kinase and the expression of TOR pathway-related genes were significantly changed when shoot-to-root auxin transport was reduced by NPA treatment. Taken together, it is concluded that low-N stress increases shoot-to-root auxin transport which enhances root elongation via auxin-dependent acid growth and the auxin-regulated TOR pathway in maize.
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Affiliation(s)
- Xichao Sun
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China; Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China.
| | - Huan Chen
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China.
| | - Peng Wang
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China.
| | - Fanjun Chen
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China.
| | - Lixing Yuan
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China.
| | - Guohua Mi
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China.
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15
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Abstract
Abstract
Background
Organisms show an incredibly diverse array of body and organ shapes that are both unique to their taxon and important for adapting to their environment. Achieving these specific shapes involves coordinating the many processes that transform single cells into complex organs, and regulating their growth so that they can function within a fully-formed body.
Main text
Conceptually, body and organ shape can be separated in two categories, although in practice these categories need not be mutually exclusive. Body shape results from the extent to which organs, or parts of organs, grow relative to each other. The patterns of relative organ size are characterized using allometry. Organ shape, on the other hand, is defined as the geometric features of an organ’s component parts excluding its size. Characterization of organ shape is frequently described by the relative position of homologous features, known as landmarks, distributed throughout the organ. These descriptions fall into the domain of geometric morphometrics.
Conclusion
In this review, we discuss the methods of characterizing body and organ shape, the developmental programs thought to underlie each, highlight when and how the mechanisms regulating body and organ shape might overlap, and provide our perspective on future avenues of research.
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16
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Brunkard JO. Exaptive Evolution of Target of Rapamycin Signaling in Multicellular Eukaryotes. Dev Cell 2020; 54:142-155. [PMID: 32649861 PMCID: PMC7346820 DOI: 10.1016/j.devcel.2020.06.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/12/2020] [Accepted: 06/18/2020] [Indexed: 12/16/2022]
Abstract
Target of rapamycin (TOR) is a protein kinase that coordinates metabolism with nutrient and energy availability in eukaryotes. TOR and its primary interactors, RAPTOR and LST8, have been remarkably evolutionarily static since they arose in the unicellular last common ancestor of plants, fungi, and animals, but the upstream regulatory mechanisms and downstream effectors of TOR signaling have evolved considerable diversity in these separate lineages. Here, I focus on the roles of exaptation and adaptation in the evolution of novel signaling axes in the TOR network in multicellular eukaryotes, concentrating especially on amino acid sensing, cell-cell signaling, and cell differentiation.
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Affiliation(s)
- Jacob O. Brunkard
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA 94720, USA,Plant Gene Expression Center, U.S. Department of Agriculture Agricultural Research Service, Albany, CA 94710, USA,Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA,Corresponding author
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17
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Xiong F, Liu M, Zhuo F, Yin H, Deng K, Feng S, Liu Y, Luo X, Feng L, Zhang S, Li Z, Ren M. Host-induced gene silencing of BcTOR in Botrytis cinerea enhances plant resistance to grey mould. MOLECULAR PLANT PATHOLOGY 2019; 20:1722-1739. [PMID: 31622007 PMCID: PMC6859489 DOI: 10.1111/mpp.12873] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Botrytis cinerea is the causal agent of grey mould for more than 200 plant species, including economically important vegetables, fruits and crops, which leads to economic losses worldwide. Target of rapamycin (TOR) acts a master regulator to control cell growth and proliferation by integrating nutrient, energy and growth factors in eukaryotic species, but little is known about whether TOR can function as a practicable target in the control of plant fungal pathogens. Here, we characterize TOR signalling of B. cinerea in the regulation of growth and pathogenicity as well as its potential value in genetic engineering for crop protection by bioinformatics analysis, pharmacological assays, biochemistry and genetics approaches. The results show that conserved TOR signalling occurs, and a functional FK506-binding protein 12 kD (FKBP12) mediates the interaction between rapamycin and B. cinerea TOR (BcTOR). RNA sequencing (RNA-Seq) analysis revealed that BcTOR displayed conserved functions, particularly in controlling growth and metabolism. Furthermore, pathogenicity assay showed that BcTOR inhibition efficiently reduces the infection of B. cinerea in plant leaves of Arabidopsis and potato or tomato fruits. Additionally, transgenic plants expressing double-stranded RNA of BcTOR through the host-induced gene silencing method could produce abundant small RNAs targeting BcTOR, and significantly block the occurrence of grey mould in potato and tomato. Taken together, our results suggest that BcTOR is an efficient target for genetic engineering in control of grey mould, and also a potential and promising target applied in the biocontrol of plant fungal pathogens.
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Affiliation(s)
- Fangjie Xiong
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Mei Liu
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Fengping Zhuo
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
- School of Chemistry and Chemical EngineeringChongqing University of Science and TechnologyChongqing401331China
| | - Huan Yin
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Kexuan Deng
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Shun Feng
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Yudong Liu
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Xiumei Luo
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Li Feng
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Shumin Zhang
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Zhengguo Li
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Maozhi Ren
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
- Institute of Urban AgricultureChinese Academy of Agricultural Sciences/National Chengdu Agricultural Science and Technology CenterChengdu610000China
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18
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Liu N, Yun Y, Yin Y, Hahn M, Ma Z, Chen Y. Lipid droplet biogenesis regulated by the FgNem1/Spo7-FgPah1 phosphatase cascade plays critical roles in fungal development and virulence in Fusarium graminearum. THE NEW PHYTOLOGIST 2019; 223:412-429. [PMID: 30767239 DOI: 10.1111/nph.15748] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 02/08/2019] [Indexed: 06/09/2023]
Abstract
Lipid droplets (LDs) control lipid metabolism in eukaryotic cells in general. However, the biogenesis regulation and biological functions of LDs are largely unknown in pathogenic fungi. Rapamycin treatment results in a significant increase of LD biogenesis in Fusarium graminearum. Molecular mechanisms of the target of rapamycin (TOR) pathway in regulating LD biogenesis and the functions of LD in virulence of F. graminearum were investigated in depth by combining genetic, cytological and phenotypic strategies. TOR in Fusarium graminearum (FgTOR) inhibition by rapamycin induces LD biogenesis through the FgPpg1/Sit4 signaling branch. FgPpg1 promotes phosphorylation of protein phosphatase FgNem1 by the protein kinase FgCak1. The phosphorylated FgNem1 dephosphorylates the phosphatidate phosphatase FgPah1. Dephosphorylated FgPah1 is active and stimulates LD biogenesis. Moreover, deletion of FgNem1/Spo7 or FgPah1 leads to serious defects in vegetative growth, sexual development and virulence. The results of this study provide novel insights into the regulatory mechanism and biological functions of the LDs in the devastating pathogenic fungus F. graminearum.
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Affiliation(s)
- Na Liu
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yingzi Yun
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yanni Yin
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Matthias Hahn
- Department of Biology, Kaiserslautern University, 67663, Kaiserslautern, Germany
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yun Chen
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
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19
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Santos Teixeira JA, Ten Tusscher KH. The Systems Biology of Lateral Root Formation: Connecting the Dots. MOLECULAR PLANT 2019; 12:784-803. [PMID: 30953788 DOI: 10.1016/j.molp.2019.03.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 03/20/2019] [Accepted: 03/26/2019] [Indexed: 05/29/2023]
Abstract
The root system is a major determinant of a plant's access to water and nutrients. The architecture of the root system to a large extent depends on the repeated formation of new lateral roots. In this review, we discuss lateral root development from a systems biology perspective. We focus on studies combining experiments with computational modeling that have advanced our understanding of how the auxin-centered regulatory modules involved in different stages of lateral root development exert their specific functions. Moreover, we discuss how these regulatory networks may enable robust transitions from one developmental stage to the next, a subject that thus far has received limited attention. In addition, we analyze how environmental factors impinge on these modules, and the different manners in which these environmental signals are being integrated to enable coordinated developmental decision making. Finally, we provide some suggestions for extending current models of lateral root development to incorporate multiple processes and stages. Only through more comprehensive models we can fully elucidate the cooperative effects of multiple processes on later root formation, and how one stage drives the transition to the next.
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Affiliation(s)
- J A Santos Teixeira
- Computational Developmental Biology Group, Department of Biology, Utrecht University, Utrecht, the Netherlands
| | - K H Ten Tusscher
- Computational Developmental Biology Group, Department of Biology, Utrecht University, Utrecht, the Netherlands.
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20
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Signorelli S, Tarkowski ŁP, Van den Ende W, Bassham DC. Linking Autophagy to Abiotic and Biotic Stress Responses. TRENDS IN PLANT SCIENCE 2019; 24:413-430. [PMID: 30824355 PMCID: PMC6475611 DOI: 10.1016/j.tplants.2019.02.001] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 05/05/2023]
Abstract
Autophagy is a process in which cellular components are delivered to lytic vacuoles to be recycled and has been demonstrated to promote abiotic/biotic stress tolerance. Here, we review how the responses triggered by stress conditions can affect autophagy and its signaling pathways. Besides the role of SNF-related kinase 1 (SnRK1) and TOR kinases in the regulation of autophagy, abscisic acid (ABA) and its signaling kinase SnRK2 have emerged as key players in the induction of autophagy under stress conditions. Furthermore, an interplay between reactive oxygen species (ROS) and autophagy is observed, ROS being able to induce autophagy and autophagy able to reduce ROS production. We also highlight the importance of osmotic adjustment for the successful performance of autophagy and discuss the potential role of GABA in plant survival and ethylene (ET)-induced autophagy.
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Affiliation(s)
- Santiago Signorelli
- Laboratory of Molecular Plant Biology, KU Leuven, Leuven, Belgium; Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Montevideo 12900, Uruguay.
| | | | - Wim Van den Ende
- Laboratory of Molecular Plant Biology, KU Leuven, Leuven, Belgium
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
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21
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Ahmad Z, Magyar Z, Bögre L, Papdi C. Cell cycle control by the target of rapamycin signalling pathway in plants. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2275-2284. [PMID: 30918972 DOI: 10.1093/jxb/erz140] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/15/2019] [Indexed: 06/09/2023]
Abstract
Cells need to ensure a sufficient nutrient and energy supply before committing to proliferate. In response to positive mitogenic signals, such as light, sugar availability, and hormones, the target of rapamycin (TOR) signalling pathway promotes cell growth that connects to the entry and passage through the cell division cycle via multiple signalling mechanisms. Here, we summarize current understanding of cell cycle regulation by the RBR-E2F regulatory hub and the DREAM-like complexes, and highlight possible functional relationships between these regulators and TOR signalling. A genetic screen recently uncovered a downstream signalling component to TOR that regulates cell proliferation, YAK1, a member of the dual specificity tyrosine phosphorylation-regulated kinase (DYRK) family. YAK1 activates the plant-specific SIAMESE-RELATED (SMR) cyclin-dependent kinase inhibitors and therefore could be important to regulate both the CDKA-RBR-E2F pathway to control the G1/S transition and the mitotic CDKB1;1 to control the G2/M transition. TOR, as a master regulator of both protein synthesis-driven cell growth and cell proliferation is also central for cell size homeostasis. We conclude the review by briefly highlighting the potential applications of combining TOR and cell cycle knowledge in the context of ensuring future food security.
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Affiliation(s)
- Zaki Ahmad
- School of Biological Sciences, Bourne Laboratory. Royal Holloway, University of London, Egham, Surrey, UK
| | - Zoltán Magyar
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences Szeged, Hungary
| | - László Bögre
- School of Biological Sciences, Bourne Laboratory. Royal Holloway, University of London, Egham, Surrey, UK
| | - Csaba Papdi
- School of Biological Sciences, Bourne Laboratory. Royal Holloway, University of London, Egham, Surrey, UK
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22
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Caldana C, Martins MCM, Mubeen U, Urrea-Castellanos R. The magic 'hammer' of TOR: the multiple faces of a single pathway in the metabolic regulation of plant growth and development. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2217-2225. [PMID: 30722050 DOI: 10.1093/jxb/ery459] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 12/11/2018] [Indexed: 06/09/2023]
Abstract
The target of rapamycin (TOR) pathway has emerged as a central hub synchronizing plant growth according to the nutrient/energy status and environmental inputs. Molecular mechanisms through which TOR promotes plant growth involve the positive regulation of transcription of cell proliferation-associated genes, mRNA translation initiation and ribosome biogenesis, to cite a few examples. Phytohormones, light, sugars, and sulfur have been found to broadly regulate TOR activity. TOR operates as a metabolic homeostat to fine-tune anabolic processes and efficiently enable plant growth under different circumstances. However, little is known about the multiple effectors that act up- and downstream of TOR. Here, we mainly discuss recent findings related to the TOR pathway in the context of plant metabolism and highlight areas of interest that need to be addressed to keep unravelling the intricate networks governing the regulation of TOR and its function in controlling biosynthetic growth.
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Affiliation(s)
- Camila Caldana
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | | | - Umarah Mubeen
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
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23
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Van Leene J, Han C, Gadeyne A, Eeckhout D, Matthijs C, Cannoot B, De Winne N, Persiau G, Van De Slijke E, Van de Cotte B, Stes E, Van Bel M, Storme V, Impens F, Gevaert K, Vandepoele K, De Smet I, De Jaeger G. Capturing the phosphorylation and protein interaction landscape of the plant TOR kinase. NATURE PLANTS 2019; 5:316-327. [PMID: 30833711 DOI: 10.1038/s41477-019-0378-z] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/28/2019] [Indexed: 05/18/2023]
Abstract
The target of rapamycin (TOR) kinase is a conserved regulatory hub that translates environmental and nutritional information into permissive or restrictive growth decisions. Despite the increased appreciation of the essential role of the TOR complex in plants, no large-scale phosphoproteomics or interactomics studies have been performed to map TOR signalling events in plants. To fill this gap, we combined a systematic phosphoproteomics screen with a targeted protein complex analysis in the model plant Arabidopsis thaliana. Integration of the phosphoproteome and protein complex data on the one hand shows that both methods reveal complementary subspaces of the plant TOR signalling network, enabling proteome-wide discovery of both upstream and downstream network components. On the other hand, the overlap between both data sets reveals a set of candidate direct TOR substrates. The integrated network embeds both evolutionarily-conserved and plant-specific TOR signalling components, uncovering an intriguing complex interplay with protein synthesis. Overall, the network provides a rich data set to start addressing fundamental questions about how TOR controls key processes in plants, such as autophagy, auxin signalling, chloroplast development, lipid metabolism, nucleotide biosynthesis, protein translation or senescence.
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Affiliation(s)
- Jelle Van Leene
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Chao Han
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, College of Life Sciences, Shandong University, Jinan, China
| | - Astrid Gadeyne
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Dominique Eeckhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Caroline Matthijs
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Bernard Cannoot
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Nancy De Winne
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Geert Persiau
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Eveline Van De Slijke
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Brigitte Van de Cotte
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Elisabeth Stes
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Michiel Van Bel
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Ghent, Belgium
| | - Veronique Storme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Francis Impens
- Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Center for Medical Biotechnology, Ghent, Belgium
- VIB Proteomics Core, Ghent, Belgium
| | - Kris Gevaert
- Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Center for Medical Biotechnology, Ghent, Belgium
- VIB Proteomics Core, Ghent, Belgium
| | - Klaas Vandepoele
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Ghent, Belgium
| | - Ive De Smet
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
- VIB Center for Plant Systems Biology, Ghent, Belgium.
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24
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Bakshi A, Moin M, Madhav MS, Kirti PB. Target of rapamycin, a master regulator of multiple signalling pathways and a potential candidate gene for crop improvement. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:190-205. [PMID: 30411830 DOI: 10.1111/plb.12935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 06/08/2023]
Abstract
The target of rapamycin (TOR) protein regulates growth and development in photosynthetic and non-photosynthetic eukaryotes. Although the TOR regulatory networks are involved in nutrient and energy signalling, and transcriptional and translational control of multiple signalling pathways, the molecular mechanism of TOR regulation of plant abiotic stress responses is still unclear. The TOR-mediated transcriptional regulation of genes encoding ribosomal proteins (RP) is a necessity under stress conditions for balanced growth and productivity in plants. The activation of SnRKs (sucrose non-fermenting-related kinases) and the inactivation of TOR signalling in abiotic stresses is in line with the accumulation of ABA and transcriptional activation of stress responsive genes. Autophagy is induced under abiotic stress conditions, which results in degradation of proteins and the release of amino acids, which might possibly induce phosphorylation of TOR and, hence, its activation. TOR signalling also has a role in regulating ABA biosynthesis for transcriptional regulation of stress-related genes. The switch between activation and inactivation of TOR by its phosphorylation and de-phosphorylation maintains balanced growth in response to stresses. In the present review, we discuss the important signalling pathways that are regulated by TOR and try to assess the relationship between TOR signalling and tolerance to abiotic stresses in plants. The review also discusses possible cross-talk between TOR and RP genes in response to abiotic stresses.
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Affiliation(s)
- A Bakshi
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - M Moin
- Department of Biotechnology, Indian Institute of Rice Research, Hyderabad, India
| | - M S Madhav
- Department of Biotechnology, Indian Institute of Rice Research, Hyderabad, India
| | - P B Kirti
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
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Kumar P, Awasthi A, Nain V, Issac B, Puria R. Novel insights into TOR signalling in Saccharomyces cerevisiae through Torin2. Gene 2018; 669:15-27. [DOI: 10.1016/j.gene.2018.05.081] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/06/2018] [Accepted: 05/21/2018] [Indexed: 12/18/2022]
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Aznar NR, Consolo VF, Salerno GL, Martínez-Noël GM. TOR signaling downregulation increases resistance to the cereal killer Fusarium graminearum. PLANT SIGNALING & BEHAVIOR 2018; 13:e1414120. [PMID: 29227194 PMCID: PMC5846550 DOI: 10.1080/15592324.2017.1414120] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/22/2017] [Accepted: 11/27/2017] [Indexed: 05/22/2023]
Abstract
TOR is the master regulator of growth and development that senses energy availability. Biotic stress perturbs metabolic and energy homeostasis, making TOR a good candidate to participate in the plant response. Fusarium graminearum (Fusarium) produces important losses in many crops all over the world. To date, the role of TOR in Fusarium infection has remained unexplored. Here, we show that the resistance to the pathogen increases in different Arabidopsis mutants impaired in TOR complex or in wild-type plants treated with a TOR inhibitor. We conclude that TOR signaling is involved in plant defense against Fusarium.
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Affiliation(s)
- Néstor R. Aznar
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Centro de Investigaciones Biológicas (CIB-FIBA), Mar del Plata, Argentina
| | - V. Fabiana Consolo
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Centro de Investigaciones Biológicas (CIB-FIBA), Mar del Plata, Argentina
| | - Graciela L. Salerno
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Centro de Investigaciones Biológicas (CIB-FIBA), Mar del Plata, Argentina
| | - Giselle M.A. Martínez-Noël
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Centro de Investigaciones Biológicas (CIB-FIBA), Mar del Plata, Argentina
- CONTACT Giselle M.A. Martínez-Noël INBIOTEC-CONICET, Vieytes 3103, 7600, Mar del Plata, Argentina
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De Vleesschauwer D, Filipe O, Hoffman G, Seifi HS, Haeck A, Canlas P, Van Bockhaven J, De Waele E, Demeestere K, Ronald P, Hofte M. Target of rapamycin signaling orchestrates growth-defense trade-offs in plants. THE NEW PHYTOLOGIST 2018; 217:305-319. [PMID: 28905991 PMCID: PMC5711548 DOI: 10.1111/nph.14785] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/09/2017] [Indexed: 05/18/2023]
Abstract
Plant defense to microbial pathogens is often accompanied by significant growth inhibition. How plants merge immune system function with normal growth and development is still poorly understood. Here, we investigated the role of target of rapamycin (TOR), an evolutionary conserved serine/threonine kinase, in the plant defense response. We used rice as a model system and applied a combination of chemical, genetic, genomic and cell-based analyses. We demonstrate that ectopic expression of TOR and Raptor (regulatory-associated protein of mTOR), a protein previously demonstrated to interact with TOR in Arabidopsis, positively regulates growth and development in rice. Transcriptome analysis of rice cells treated with the TOR-specific inhibitor rapamycin revealed that TOR not only dictates transcriptional reprogramming of extensive gene sets involved in central and secondary metabolism, cell cycle and transcription, but also suppresses many defense-related genes. TOR overexpression lines displayed increased susceptibility to both bacterial and fungal pathogens, whereas plants with reduced TOR signaling displayed enhanced resistance. Finally, we found that TOR antagonizes the action of the classic defense hormones salicylic acid and jasmonic acid. Together, these results indicate that TOR acts as a molecular switch for the activation of cell proliferation and plant growth at the expense of cellular immunity.
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Affiliation(s)
- David De Vleesschauwer
- Laboratory of Phytopathology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Osvaldo Filipe
- Laboratory of Phytopathology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Gena Hoffman
- Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Hamed Soren Seifi
- Laboratory of Phytopathology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Ashley Haeck
- Research Group EnVOC, Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Patrick Canlas
- Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Jonas Van Bockhaven
- Laboratory of Phytopathology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Evelien De Waele
- Laboratory of Phytopathology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Kristof Demeestere
- Research Group EnVOC, Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Pamela Ronald
- Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
- Joint Bioenergy Institute, Emeryville, CA, 94608, USA
| | - Monica Hofte
- Laboratory of Phytopathology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
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Malinovsky FG, Thomsen MLF, Nintemann SJ, Jagd LM, Bourgine B, Burow M, Kliebenstein DJ. An evolutionarily young defense metabolite influences the root growth of plants via the ancient TOR signaling pathway. eLife 2017; 6:29353. [PMID: 29231169 PMCID: PMC5730369 DOI: 10.7554/elife.29353] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/27/2017] [Indexed: 11/24/2022] Open
Abstract
To optimize fitness a plant should monitor its metabolism to appropriately control growth and defense. Primary metabolism can be measured by the universally conserved TOR (Target of Rapamycin) pathway to balance growth and development with the available energy and nutrients. Recent work suggests that plants may measure defense metabolites to potentially provide a strategy ensuring fast reallocation of resources to coordinate plant growth and defense. There is little understanding of mechanisms enabling defense metabolite signaling. To identify mechanisms of defense metabolite signaling, we used glucosinolates, an important class of plant defense metabolites. We report novel signaling properties specific to one distinct glucosinolate, 3-hydroxypropylglucosinolate across plants and fungi. This defense metabolite, or derived compounds, reversibly inhibits root growth and development. 3-hydroxypropylglucosinolate signaling functions via genes in the ancient TOR pathway. If this event is not unique, this raises the possibility that other evolutionarily new plant metabolites may link to ancient signaling pathways. Plants, like all organisms, must invest their resources carefully. Growing new roots or shoots may allow a plant to better exploit its environment. But a plant should never leave itself vulnerable to disease. As such, there must be a balance between allocating resources to growth or to defense. Brassicas like cabbage, Brussels sprouts and wasabi use unique compounds called glucosinolates to protect themselves against pests and disease-causing microbes. These same compounds give these vegetables their distinctive flavors, and they are the source of many of the health benefits linked to eating these vegetables. Yet it was not known if glucosinolates could also affect a plant’s growth and development. Malinovsky et al. tested a number of purified glucosinolates with the model plant Arabidopsis thaliana, and found that one (called 3-hydroxypropylglucosinolate) caused the plants to grow with stunted roots. When 10 other species of plant were grown with this glucosinolate, almost all had shorter-than-normal roots. The effect was not limited to plants; baker’s yeast also grew less when its liquid media contained the plant-derived compound. The reason glucosinolates can protect plants against insect pests, provide us with health benefits, and widely inhibit growth is most likely because they have evolved to interact with proteins that are found in many different organisms.Indeed, through experiments with mutant Arabidopsis plants, Malinovsky et al. revealed that their glucosinolate influences the TOR complex. This complex of proteins works in an ancient and widespread signaling pathway that balances growth and development with the available energy and nutrients in organisms ranging from humans to yeast to plants. The TOR complex plays such a vital role in living cells that problems with this complex have been linked to diseases such as cancer and heart disease. Importantly, the chemical structure of this glucosinolate is unlike other compounds that have already been tested against the TOR complex. As such, it is possible that this glucosinolate might lead to new drugs for a range of human diseases. Further, as this compound affects plant growth, it could also act as a starting point for new herbicides. Together these findings show how studying molecules made in model organisms and understanding how they function can lead to the identification of new compounds and targets with an unexpectedly wide range of potential uses.
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Affiliation(s)
- Frederikke Gro Malinovsky
- DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie-Louise F Thomsen
- DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sebastian J Nintemann
- DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lea Møller Jagd
- DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Baptiste Bourgine
- DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Meike Burow
- DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Daniel J Kliebenstein
- DynaMo Center, Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Plant Sciences, University of California, Davis, Davis, United States
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Palmer NA, Saathoff AJ, Scully ED, Tobias CM, Twigg P, Madhavan S, Schmer M, Cahoon R, Sattler SE, Edmé SJ, Mitchell RB, Sarath G. Seasonal below-ground metabolism in switchgrass. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:1059-1075. [PMID: 29030891 DOI: 10.1111/tpj.13742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/26/2017] [Accepted: 09/29/2017] [Indexed: 05/25/2023]
Abstract
Switchgrass (Panicum virgatum), a perennial, polyploid, C4 warm-season grass is among the foremost herbaceous species being advanced as a source of biomass for biofuel end uses. At the end of every growing season, the aerial tissues senesce, and the below-ground rhizomes become dormant. Future growth is dependent on the successful over-wintering of the rhizomes. Although the importance of rhizome health to overall year-upon-year plant productivity has been long recognized, there is limited information on seasonal changes occurring during dormancy at both the transcriptome and metabolite levels. Here, global changes in transcriptomes and metabolites were investigated over two growing seasons in rhizomes harvested from field-grown plants. The objectives were: (a) synthesize information on cellular processes that lead to dormancy; and (b) provide models that could account for major metabolic pathways present in dormant switchgrass rhizomes. Overall, metabolism during dormancy appeared to involve discrete but interrelated events. One was a response to abscisic acid that resulted in dehydration, increases in osmolytes and upregulation of autophagic processes, likely through the target of rapamycin complex and sucrose non-fermentative-related kinase-based signaling cascades. Another was a recalibration of energy transduction through apparent reductions in mitochondrial oxidative phosphorylation, increases in substrate level generation of ATP and reducing equivalents, and recycling of N and possibly CO2 through refixation. Lastly, transcript abundances indicated that cold-related signaling was also occurring. Altogether, these data provide a detailed overview of rhizome metabolism, especially during dormancy, which can be exploited in the future to improve winter survival in switchgrass.
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Affiliation(s)
- Nathan A Palmer
- Wheat, Sorghum, and Forage Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska at Lincoln, Lincoln, NE, 68583, USA
| | - Aaron J Saathoff
- Wheat, Sorghum, and Forage Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska at Lincoln, Lincoln, NE, 68583, USA
| | - Erin D Scully
- Stored Product Insect and Engineering Research Unit, USDA-Agricultural Research Service Center for Grain and Animal Health, Manhattan, KS, 66502, USA
| | - Christian M Tobias
- Crop Improvement and Genetics Research, USDA-ARS, Albany, CA, 94710, USA
| | - Paul Twigg
- Biology Department, University of Nebraska at Kearney, Kearney, NE, 68849, USA
| | | | - Marty Schmer
- Agroecosystem Management Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska at Lincoln, Lincoln, NE, 68583, USA
| | - Rebecca Cahoon
- Department of Biochemistry, University of Nebraska at Lincoln, Lincoln, NE, 68588, USA
| | - Scott E Sattler
- Wheat, Sorghum, and Forage Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska at Lincoln, Lincoln, NE, 68583, USA
| | - Serge J Edmé
- Wheat, Sorghum, and Forage Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska at Lincoln, Lincoln, NE, 68583, USA
| | - Robert B Mitchell
- Wheat, Sorghum, and Forage Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska at Lincoln, Lincoln, NE, 68583, USA
| | - Gautam Sarath
- Wheat, Sorghum, and Forage Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska at Lincoln, Lincoln, NE, 68583, USA
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30
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Humplík JF, Bergougnoux V, Van Volkenburgh E. To Stimulate or Inhibit? That Is the Question for the Function of Abscisic Acid. TRENDS IN PLANT SCIENCE 2017; 22:830-841. [PMID: 28843765 DOI: 10.1016/j.tplants.2017.07.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 06/12/2017] [Accepted: 07/26/2017] [Indexed: 05/18/2023]
Abstract
Physiologically, abscisic acid (ABA) is believed to be a general inhibitor of plant growth, including during the crucial early development of seedlings. However, this view contradicts many reports of stimulatory effects of ABA that, so far, have not been considered in the debate concerning ABA's function in plant development. To address this apparent contradiction, we propose a hypothetical mechanism to explain how ABA might contribute to the promotion of cell expansion. We wish to overturn conventional views on ABA's role during juvenile plant development and put forward the idea that, as for other phytohormones, the role of ABA is determined by dose and sensitivity and ranges from stimulatory to inhibitory effects.
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Affiliation(s)
- Jan F Humplík
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany Czech Academy of Sciences and Palacký University Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic; Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic; These authors contributed equally to the work.
| | - Véronique Bergougnoux
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic; These authors contributed equally to the work
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Zeng Z, Huang H, Han N, Huang CY, Langridge P, Bian H, Zhu M. Endopolyploidy levels in barley vary in different root types and significantly decrease under phosphorus deficiency. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 118:11-21. [PMID: 28601019 DOI: 10.1016/j.plaphy.2017.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/02/2017] [Accepted: 06/02/2017] [Indexed: 06/07/2023]
Abstract
Increased endopolyploidy is important for plant growth and development as well as for adaptation to environmental stresses. However, little is known about the role of reduced endopolyploidy, especially in root systems. In this report, endopolyploidy variations were examined in different types of barley (Hordeum vulgare L.) roots, and the effects of phosphorus (P) deficiency and salinity (NaCl) stress on root endopolyploidy were also studied. The results showed that the endopolyploidy levels were lower in lateral roots than in either primary or nodal roots. The lower endopolyploidy in lateral roots was attributed to cortical cells. P deficiency reduced the endopolyploidy levels in lateral roots and mature zone of primary roots. By contrast, salinity had no effects on the endopolyploidy levels in either lateral or primary roots, but had a minor effect on nodal roots. Transcript analysis of cell cycle-related genes showed that multiple cell cycle-related genes were more highly expressed in lateral roots than in primary roots, suggesting their roles in lowering endopolyploidy. P deficiency reduced HvCCS52A1 transcripts in the mature zone of primary roots, but had little effect on the transcripts of 12 cell cycle-related genes in lateral roots, suggesting that endopolyploidy regulation differs between lateral roots and primary roots. Our results revealed that endopolyploidy reduction in root systems could be an integrated part of endopolyploidy plasticity in barley growth and development as well as in adaptation to a low P environment.
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Affiliation(s)
- Zhanghui Zeng
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Huahong Huang
- Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang, 311300, China
| | - Ning Han
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Chun Y Huang
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Peter Langridge
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Hongwu Bian
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| | - Muyuan Zhu
- Institute of Genetic and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
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Deng K, Dong P, Wang W, Feng L, Xiong F, Wang K, Zhang S, Feng S, Wang B, Zhang J, Ren M. The TOR Pathway Is Involved in Adventitious Root Formation in Arabidopsis and Potato. FRONTIERS IN PLANT SCIENCE 2017; 8:784. [PMID: 28553309 PMCID: PMC5427086 DOI: 10.3389/fpls.2017.00784] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/26/2017] [Indexed: 05/14/2023]
Abstract
In the agriculture industry, adventitious root formation is a core issue of plants asexual propagation. However, the underlying molecular mechanism of adventitious root formation is far beyond understanding. In present study we found that target of rapamycin (TOR) signaling plays a key role in adventitious root formation in potato and Arabidopsis. The core components of TOR complex including TOR, RAPTOR, and LST8 are highly conserved in potato, but the seedlings of potato are insensitive to rapamycin, implying FK506 Binding Protein 12 KD (FKBP12) lost the function to bridge the interaction of rapamycin and TOR in potato. To dissect TOR signaling in potato, the rapamycin hypersensitive potato plants (BP12-OE) were engineered by introducing yeast FKBP12 (ScFKBP12) into potato. We found that rapamycin can significantly attenuate the capability of adventitious root formation in BP12-OE potatoes. KU63794 (KU, an active-site TOR inhibitor) combined with rapamycin can more significantly suppress adventitious root formation of BP12-OE potato than the single treatments, such as KU63794 or rapamycin, indicating its synergistic inhibitory effects on potato adventitious root formation. Furthermore, RNA-seq data showed that many genes associated with auxin signaling pathway were altered when BP12-OE potato seedlings were treated with rapamycin + KU, suggesting that TOR may play a major role in adventitious root formation via auxin signaling. The auxin receptor mutant tir1 was sensitive to TOR inhibitors and the double and quadruple mutants including tir1afb2, tir1afb3, and tir1afb1afb2afb3 displayed more sensitive to asTORis than single mutant tir1. Consistently, overexpression of AtTIR1 in Arabidopsis and potato can partially overcome the inhibitory effect of asTORis and promote adventitious root formation under asTORis treatments. These observations suggest that TOR signaling regulates adventitious root formation by mediating auxin signaling in Arabidopsis and potato.
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Affiliation(s)
- Kexuan Deng
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Pan Dong
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Wanjing Wang
- College of Agronomy and Biotechnology, Southwest UniversityChongqing, China
| | - Li Feng
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Fangjie Xiong
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Kai Wang
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Shumin Zhang
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Shun Feng
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Bangjun Wang
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Life Sciences, Southwest UniversityChongqing, China
| | - Jiankui Zhang
- College of Agronomy and Biotechnology, Southwest UniversityChongqing, China
| | - Maozhi Ren
- School of Life Sciences, Chongqing UniversityChongqing, China
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Kumari A, Ray K, Sadhna S, Pandey AK, Sreelakshmi Y, Sharma R. Metabolomic homeostasis shifts after callus formation and shoot regeneration in tomato. PLoS One 2017; 12:e0176978. [PMID: 28481937 PMCID: PMC5421760 DOI: 10.1371/journal.pone.0176978] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 04/20/2017] [Indexed: 11/21/2022] Open
Abstract
Plants can regenerate from a variety of tissues on culturing in appropriate media. However, the metabolic shifts involved in callus formation and shoot regeneration are largely unknown. The metabolic profiles of callus generated from tomato (Solanum lycopersicum) cotyledons and that of shoot regenerated from callus were compared with the pct1-2 mutant that exhibits enhanced polar auxin transport and the shr mutant that exhibits elevated nitric oxide levels. The transformation from cotyledon to callus involved a major shift in metabolite profiles with denser metabolic networks in the callus. In contrast, the transformation from callus to shoot involved minor changes in the networks. The metabolic networks in pct1-2 and shr mutants were distinct from wild type and were rewired with shifts in endogenous hormones and metabolite interactions. The callus formation was accompanied by a reduction in the levels of metabolites involved in cell wall lignification and cellular immunity. On the contrary, the levels of monoamines were upregulated in the callus and regenerated shoot. The callus formation and shoot regeneration were accompanied by an increase in salicylic acid in wild type and mutants. The transformation to the callus and also to the shoot downregulated LST8 and upregulated TOR transcript levels indicating a putative linkage between metabolic shift and TOR signalling pathway. The network analysis indicates that shift in metabolite profiles during callus formation and shoot regeneration is governed by a complex interaction between metabolites and endogenous hormones.
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Affiliation(s)
- Alka Kumari
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - Kamalika Ray
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - Sadhna Sadhna
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - Arun Kumar Pandey
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - Yellamaraju Sreelakshmi
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - Rameshwar Sharma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, India
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34
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Song Y, Zhao G, Zhang X, Li L, Xiong F, Zhuo F, Zhang C, Yang Z, Datla R, Ren M, Li F. The crosstalk between Target of Rapamycin (TOR) and Jasmonic Acid (JA) signaling existing in Arabidopsis and cotton. Sci Rep 2017; 7:45830. [PMID: 28374843 PMCID: PMC5379187 DOI: 10.1038/srep45830] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/06/2017] [Indexed: 12/31/2022] Open
Abstract
Target of rapamycin (TOR) acts as an important regulator of cell growth, development and stress responses in most examined diploid eukaryotes. However, little is known about TOR in tetraploid species such as cotton. Here, we show that TORC1-S6K-RPS6, the major signaling components, are conserved and further expanded in cotton genome. Though the cotton seedlings are insensitive to rapamycin, AZD8055, the second-generation inhibitor of TOR, can significantly suppress the growth in cotton. Global transcriptome analysis revealed that genes associated with jasmonic acid (JA) biosynthesis and transduction were significantly altered in AZD8055 treated cotton seedlings, suggesting the potential crosstalk between TOR and JA signaling. Pharmacological and genetic approaches have been employed to get further insights into the molecular mechanism of the crosstalk between TOR and JA. Combination of AZD8055 with methyl jasmonate can synergistically inhibit cotton growth, and additionally JA levels were significantly increased when cotton seedlings were subjected to AZD8055. JA biosynthetic and signaling mutants including jar1, coi1-2 and myc2-2 displayed TOR inhibitor-resistant phenotypes, whereas COI1 overexpression transgenic lines and jaz10 exhibited sensitivity to AZD8055. Consistently, cotton JAZ can partially rescue TOR-suppressed phenotypes in Arabidopsis. These evidences revealed that the crosstalk between TOR and JA pathway operates in cotton and Arabidopsis.
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Affiliation(s)
- Yun Song
- State Key Laboratory of Cotton Biology, Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang, Henan Province, China
| | - Ge Zhao
- State Key Laboratory of Cotton Biology, Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang, Henan Province, China
| | - Xueyan Zhang
- State Key Laboratory of Cotton Biology, Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang, Henan Province, China
| | - Linxuan Li
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Fangjie Xiong
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Fengping Zhuo
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Chaojun Zhang
- State Key Laboratory of Cotton Biology, Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang, Henan Province, China
| | - Zuoren Yang
- State Key Laboratory of Cotton Biology, Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang, Henan Province, China
| | - Raju Datla
- National Research Council of Canada, Saskatoon, Canada
| | - Maozhi Ren
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Fuguang Li
- State Key Laboratory of Cotton Biology, Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang, Henan Province, China
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Brasil JN, Costa CNM, Cabral LM, Ferreira PCG, Hemerly AS. The plant cell cycle: Pre-Replication complex formation and controls. Genet Mol Biol 2017; 40:276-291. [PMID: 28304073 PMCID: PMC5452130 DOI: 10.1590/1678-4685-gmb-2016-0118] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 08/16/2016] [Indexed: 01/07/2023] Open
Abstract
The multiplication of cells in all living organisms requires a tight regulation of DNA replication. Several mechanisms take place to ensure that the DNA is replicated faithfully and just once per cell cycle in order to originate through mitoses two new daughter cells that contain exactly the same information from the previous one. A key control mechanism that occurs before cells enter S phase is the formation of a pre-replication complex (pre-RC) that is assembled at replication origins by the sequential association of the origin recognition complex, followed by Cdt1, Cdc6 and finally MCMs, licensing DNA to start replication. The identification of pre-RC members in all animal and plant species shows that this complex is conserved in eukaryotes and, more importantly, the differences between kingdoms might reflect their divergence in strategies on cell cycle regulation, as it must be integrated and adapted to the niche, ecosystem, and the organism peculiarities. Here, we provide an overview of the knowledge generated so far on the formation and the developmental controls of the pre-RC mechanism in plants, analyzing some particular aspects in comparison to other eukaryotes.
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Affiliation(s)
- Juliana Nogueira Brasil
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.,Centro Universitário Christus, Fortaleza, CE, Brazil
| | - Carinne N Monteiro Costa
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.,Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Luiz Mors Cabral
- Departamento de Biologia Celular e Molecular, Universidade Federal Fluminense, Niteroi, RJ, Brazil
| | - Paulo C G Ferreira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Adriana S Hemerly
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Xiong F, Zhang R, Meng Z, Deng K, Que Y, Zhuo F, Feng L, Guo S, Datla R, Ren M. Brassinosteriod Insensitive 2 (BIN2) acts as a downstream effector of the Target of Rapamycin (TOR) signaling pathway to regulate photoautotrophic growth in Arabidopsis. THE NEW PHYTOLOGIST 2017; 213:233-249. [PMID: 27479935 DOI: 10.1111/nph.14118] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 06/20/2016] [Indexed: 05/19/2023]
Abstract
The components of the target of rapamycin (TOR) signaling pathway have been well characterized in heterotrophic organisms from yeast to humans. However, because of rapamycin insensitivity, embryonic lethality in tor null mutants and a lack of reliable ways of detecting TOR protein kinase in higher plants, the key players upstream and downstream of TOR remain largely unknown in plants. Using engineered rapamycin-sensitive Binding Protein 12-2 (BP12-2) plants, the present study showed that combined treatment with rapamycin and active-site TOR inhibitors (asTORis) results in synergistic inhibition of TOR activity and plant growth in Arabidopsis. Based on this system, we revealed that TOR signaling plays a crucial role in modulating the transition from heterotrophic to photoautotrophic growth in Arabidopsis. Ribosomal protein S6 kinase 2 (S6K2) was identified as a direct downstream target of TOR, and the growth of TOR-suppressed plants could be rescued by up-regulating S6K2. Systems, genetic, and biochemical analyses revealed that Brassinosteriod Insensitive 2 (BIN2) acts as a novel downstream effector of S6K2, and the phosphorylation of BIN2 depends on TOR-S6K2 signaling in Arabidopsis. By combining pharmacological with genetic and biochemical approaches, we determined that the TOR-S6K2-BIN2 signaling pathway plays important roles in regulating the photoautotrophic growth of Arabidopsis.
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Affiliation(s)
- Fangjie Xiong
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Rui Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Zhigang Meng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Kexuan Deng
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Yumei Que
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Fengping Zhuo
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Li Feng
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Sundui Guo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Raju Datla
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, SK, S7N0W9, Canada
| | - Maozhi Ren
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
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Li L, Sheen J. Dynamic and diverse sugar signaling. CURRENT OPINION IN PLANT BIOLOGY 2016; 33:116-125. [PMID: 27423125 PMCID: PMC5050104 DOI: 10.1016/j.pbi.2016.06.018] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 06/17/2016] [Accepted: 06/27/2016] [Indexed: 05/18/2023]
Abstract
Sugars fuel life and exert numerous regulatory actions that are fundamental to all life forms. There are two principal mechanisms underlie sugar 'perception and signal transduction' in biological systems. Direct sensing and signaling is triggered via sugar-binding sensors with a broad range of affinity and specificity, whereas sugar-derived bioenergetic molecules and metabolites modulate signaling proteins and indirectly relay sugar signals. This review discusses the emerging sugar signals and potential sugar sensors discovered in plant systems. The findings leading to informative understanding of physiological regulation by sugars are considered and assessed. Comparative transcriptome analyses highlight the primary and dynamic sugar responses and reveal the convergent and specific regulators of key biological processes in the sugar-signaling network.
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Affiliation(s)
- Lei Li
- Department of Genetics, Harvard Medical School, USA; Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, MA 02114, USA
| | - Jen Sheen
- Department of Genetics, Harvard Medical School, USA; Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, MA 02114, USA.
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Pfeiffer A, Janocha D, Dong Y, Medzihradszky A, Schöne S, Daum G, Suzaki T, Forner J, Langenecker T, Rempel E, Schmid M, Wirtz M, Hell R, Lohmann JU. Integration of light and metabolic signals for stem cell activation at the shoot apical meristem. eLife 2016; 5. [PMID: 27400267 PMCID: PMC4969040 DOI: 10.7554/elife.17023] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 07/09/2016] [Indexed: 12/12/2022] Open
Abstract
A major feature of embryogenesis is the specification of stem cell systems, but in contrast to the situation in most animals, plant stem cells remain quiescent until the postembryonic phase of development. Here, we dissect how light and metabolic signals are integrated to overcome stem cell dormancy at the shoot apical meristem. We show on the one hand that light is able to activate expression of the stem cell inducer WUSCHEL independently of photosynthesis and that this likely involves inter-regional cytokinin signaling. Metabolic signals, on the other hand, are transduced to the meristem through activation of the TARGET OF RAPAMYCIN (TOR) kinase. Surprisingly, TOR is also required for light signal dependent stem cell activation. Thus, the TOR kinase acts as a central integrator of light and metabolic signals and a key regulator of stem cell activation at the shoot apex. DOI:http://dx.doi.org/10.7554/eLife.17023.001 Plants are able to grow and develop throughout their lives thanks to groups of stem cells at the tips of their shoots and roots, which can constantly divide to produce new cells. Energy captured from sunlight during a process called photosynthesis is the main source of energy for most plants. Therefore, the amount and quality of light in the environment has a big influence on how plants grow and develop. An enzyme called TOR kinase can sense energy levels in animal cells and regulate many processes including growth and cell division. Plants also have a TOR kinase, but it is less clear if it plays the same role in plants, and whether it can respond to light. Plant stem cells only start to divide after the seed germinates. In shoots, a protein called WUSCHEL is required to maintain stem cells in an active state. Here, Pfeiffer et al. studied how shoot stem cells are activated in response to environmental signals in a plant known as Arabidopsis. The experiments show that light is able to activate the production of WUSCHEL independently of photosynthesis via a signal pathway that depends on TOR kinase. The stem cells do not directly sense light; instead other cells detect the light and relay the information to the stem cells with the help of a hormone called cytokinin. Further experiments show that information about energy levels in cells is relayed via another signal pathway that also involves the TOR kinase. Therefore, Pfeiffer et al.’s findings suggest that the activation of TOR by light allows plant cells to anticipate how much energy will be available and efficiently tune their growth and development to cope with the environmental conditions. Future challenges are to understand how TOR kinase is regulated by light signals and how this enzyme is able to act on WUSCHEL to trigger stem cell division. DOI:http://dx.doi.org/10.7554/eLife.17023.002
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Affiliation(s)
- Anne Pfeiffer
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Denis Janocha
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Yihan Dong
- Department of Molecular Plant Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Anna Medzihradszky
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Stefanie Schöne
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Gabor Daum
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Takuya Suzaki
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Joachim Forner
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Tobias Langenecker
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Eugen Rempel
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Markus Schmid
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Markus Wirtz
- Department of Molecular Plant Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Rüdiger Hell
- Department of Molecular Plant Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Jan U Lohmann
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
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Zhang Z, Zhu JY, Roh J, Marchive C, Kim SK, Meyer C, Sun Y, Wang W, Wang ZY. TOR Signaling Promotes Accumulation of BZR1 to Balance Growth with Carbon Availability in Arabidopsis. Curr Biol 2016; 26:1854-60. [PMID: 27345161 DOI: 10.1016/j.cub.2016.05.005] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 04/04/2016] [Accepted: 05/03/2016] [Indexed: 11/19/2022]
Abstract
For maintenance of cellular homeostasis, the actions of growth-promoting hormones must be attenuated when nutrient and energy become limiting. The molecular mechanisms that coordinate hormone-dependent growth responses with nutrient availability remain poorly understood in plants [1, 2]. The target of rapamycin (TOR) kinase is an evolutionarily conserved master regulator that integrates nutrient and energy signaling to regulate growth and homeostasis in both animals and plants [3-7]. Here, we show that sugar signaling through TOR controls the accumulation of the brassinosteroid (BR)-signaling transcription factor BZR1, which is essential for growth promotion by multiple hormonal and environmental signals [8-11]. Starvation, caused by shifting of light-grown Arabidopsis seedlings into darkness, as well as inhibition of TOR by inducible RNAi, led to plant growth arrest and reduced expression of BR-responsive genes. The growth arrest caused by TOR inactivation was partially recovered by BR treatment and the gain-of-function mutation bzr1-1D, which causes accumulation of active forms of BZR1 [12]. Exogenous sugar promoted BZR1 accumulation and seedling growth, but such sugar effects were largely abolished by inactivation of TOR, whereas the effect of TOR inactivation on BZR1 degradation is abolished by inhibition of autophagy and by the bzr1-1D mutation. These results indicate that cellular starvation leads sequentially to TOR inactivation, autophagy, and BZR1 degradation. Such regulation of BZR1 accumulation by glucose-TOR signaling allows carbon availability to control the growth promotion hormonal programs, ensuring supply-demand balance in plant growth.
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Affiliation(s)
- Zhenzhen Zhang
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang, Hebei 050024, China; Center of Basic Forestry and Proteomics, Haixia Institute of Science and Technology (HIST), Fujian Agriculture and Forestry University (FAFU), Fuzhou 350002, China
| | - Jia-Ying Zhu
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Jeehee Roh
- Department of Life Science, Chung-Ang University, Seoul 156756, Korea
| | - Chloé Marchive
- IJPB, UMR 1318 INRA-AgroParisTech, ERL CNRS 3559, Saclay Plant Sciences, 78026 Versailles, France
| | - Seong-Ki Kim
- Department of Life Science, Chung-Ang University, Seoul 156756, Korea
| | - Christian Meyer
- IJPB, UMR 1318 INRA-AgroParisTech, ERL CNRS 3559, Saclay Plant Sciences, 78026 Versailles, France
| | - Yu Sun
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang, Hebei 050024, China
| | - Wenfei Wang
- Center of Basic Forestry and Proteomics, Haixia Institute of Science and Technology (HIST), Fujian Agriculture and Forestry University (FAFU), Fuzhou 350002, China
| | - Zhi-Yong Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
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Considine MJ, Considine JA. On the language and physiology of dormancy and quiescence in plants. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3189-203. [PMID: 27053719 DOI: 10.1093/jxb/erw138] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The language of dormancy is rich and poetic, as researchers spanning disciplines and decades have attempted to understand the spell that entranced 'Sleeping Beauty', and how she was gently awoken. The misleading use of 'dormancy', applied to annual axillary buds, for example, has confounded progress. Language is increasingly important as genetic and genomic approaches become more accessible to species of agricultural and ecological importance. Here we examine how terminology has been applied to different eco-physiological states in plants, and with pertinent reference to quiescent states described in other domains of life, in order to place plant quiescence and dormancy in a more complete context than previously described. The physiological consensus defines latency or quiescence as opportunistic avoidance states, where growth resumes in favourable conditions. In contrast, the dormant state in higher plants is entrained in the life history of the organism. Competence to resume growth requires quantitative and specific conditioning. This definition applies only to the embryo of seeds and specialized meristems in higher plants; however, mechanistic control of dormancy extends to mobile signals from peripheral tissues and organs, such as the endosperm of seed or subtending leaf of buds. The distinction between dormancy, quiescence, and stress-hardiness remains poorly delineated, most particularly in buds of winter perennials, which comprise multiple meristems of differing organogenic states. Studies in seeds have shown that dormancy is not a monogenic trait, and limited study has thus far failed to canalize dormancy as seen in seeds and buds. We argue that a common language, based on physiology, is central to enable further dissection of the quiescent and dormant states in plants. We direct the topic largely to woody species showing a single cycle of growth and reproduction per year, as these bear the majority of global timber, fruit, and nut production, as well being of great ecological value. However, for context and hypotheses, we draw on knowledge from annuals and other specialized plant conditions, from a perspective of the major physical, metabolic, and molecular cues that regulate cellular activity.
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Affiliation(s)
- Michael J Considine
- School of Plant Biology, and The Institute of Agriculture, The University of Western Australia, Perth, WA 6009 Australia Department of Agriculture and Food Western Australia, South Perth, WA 6151 Australia Centre for Plant Sciences, University of Leeds, Leeds, Yorkshire LS2 9JT, UK
| | - John A Considine
- School of Plant Biology, and The Institute of Agriculture, The University of Western Australia, Perth, WA 6009 Australia
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Dobrenel T, Caldana C, Hanson J, Robaglia C, Vincentz M, Veit B, Meyer C. TOR Signaling and Nutrient Sensing. ANNUAL REVIEW OF PLANT BIOLOGY 2016; 67:261-85. [PMID: 26905651 DOI: 10.1146/annurev-arplant-043014-114648] [Citation(s) in RCA: 243] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
All living organisms rely on nutrients to sustain cell metabolism and energy production, which in turn need to be adjusted based on available resources. The evolutionarily conserved target of rapamycin (TOR) protein kinase is a central regulatory hub that connects environmental information about the quantity and quality of nutrients to developmental and metabolic processes in order to maintain cellular homeostasis. TOR is activated by both nitrogen and carbon metabolites and promotes energy-consuming processes such as cell division, mRNA translation, and anabolism in times of abundance while repressing nutrient remobilization through autophagy. In animals and yeasts, TOR acts antagonistically to the starvation-induced AMP-activated kinase (AMPK)/sucrose nonfermenting 1 (Snf1) kinase, called Snf1-related kinase 1 (SnRK1) in plants. This review summarizes the immense knowledge on the relationship between TOR signaling and nutrients in nonphotosynthetic organisms and presents recent findings in plants that illuminate the crucial role of this pathway in conveying nutrient-derived signals and regulating many aspects of metabolism and growth.
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Affiliation(s)
- Thomas Dobrenel
- Institut Jean-Pierre Bourgin, UMR 1318 INRA AgroParisTech, ERL CNRS 3559, Saclay Plant Sciences, Versailles 78026, France;
- Umeå Plant Science Center, Department of Plant Physiology, Umeå University, Umeå 90187, Sweden
| | - Camila Caldana
- Molecular Physiology of Plant Biomass Production Group, Max Planck Partner Group, Brazilian Bioethanol Science and Technology Laboratory, CEP 13083-100 Campinas, São Paulo, Brazil
| | - Johannes Hanson
- Umeå Plant Science Center, Department of Plant Physiology, Umeå University, Umeå 90187, Sweden
| | - Christophe Robaglia
- Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, DSV, IBEB, SBVME, CEA, CNRS, Aix Marseille Université, Faculté des Sciences de Luminy, Marseille 13009, France
| | - Michel Vincentz
- Laboratório de Genética de Plantas, Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, CEP 13083-875 Campinas, São Paulo, Brazil
| | - Bruce Veit
- Forage Improvement, AgResearch, Institute of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Christian Meyer
- Institut Jean-Pierre Bourgin, UMR 1318 INRA AgroParisTech, ERL CNRS 3559, Saclay Plant Sciences, Versailles 78026, France;
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Yokawa K, Baluška F. The TOR Complex: An Emergency Switch for Root Behavior. PLANT & CELL PHYSIOLOGY 2016; 57:14-8. [PMID: 26644459 DOI: 10.1093/pcp/pcv191] [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: 09/10/2015] [Accepted: 11/20/2015] [Indexed: 05/10/2023]
Abstract
Target of rapamycin (TOR) kinase is known to be a controller of cell growth and aging, which determines the fine balance between growth rates and energy availabilities. It has been reported that many eukaryotes express TOR genes. In plants, TOR signaling modifies growth and development in response to a plant's energy status. An example of TOR action can be found in the root apices, which are active organs that explore the soil environment via vigorous growth and numerous tropisms. The exploratory nature of root apices requires a large energy supply for signaling, as well as for cell division and elongation. In the case of negative tropisms, roots must respond quickly to avoid patches of unfavorable soil conditions, again by consuming precious energy reserves. Here we review the current findings on TOR signaling in plants and animals, and propose possible roles for this important complex in driving plant root negative tropisms, particularly during light escape and salt avoidance behavior.
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Affiliation(s)
- Ken Yokawa
- IZMB, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
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Dobrenel T, Mancera-Martínez E, Forzani C, Azzopardi M, Davanture M, Moreau M, Schepetilnikov M, Chicher J, Langella O, Zivy M, Robaglia C, Ryabova LA, Hanson J, Meyer C. The Arabidopsis TOR Kinase Specifically Regulates the Expression of Nuclear Genes Coding for Plastidic Ribosomal Proteins and the Phosphorylation of the Cytosolic Ribosomal Protein S6. FRONTIERS IN PLANT SCIENCE 2016; 7:1611. [PMID: 27877176 PMCID: PMC5100631 DOI: 10.3389/fpls.2016.01611] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/12/2016] [Indexed: 05/05/2023]
Abstract
Protein translation is an energy consuming process that has to be fine-tuned at both the cell and organism levels to match the availability of resources. The target of rapamycin kinase (TOR) is a key regulator of a large range of biological processes in response to environmental cues. In this study, we have investigated the effects of TOR inactivation on the expression and regulation of Arabidopsis ribosomal proteins at different levels of analysis, namely from transcriptomic to phosphoproteomic. TOR inactivation resulted in a coordinated down-regulation of the transcription and translation of nuclear-encoded mRNAs coding for plastidic ribosomal proteins, which could explain the chlorotic phenotype of the TOR silenced plants. We have identified in the 5' untranslated regions (UTRs) of this set of genes a conserved sequence related to the 5' terminal oligopyrimidine motif, which is known to confer translational regulation by the TOR kinase in other eukaryotes. Furthermore, the phosphoproteomic analysis of the ribosomal fraction following TOR inactivation revealed a lower phosphorylation of the conserved Ser240 residue in the C-terminal region of the 40S ribosomal protein S6 (RPS6). These results were confirmed by Western blot analysis using an antibody that specifically recognizes phosphorylated Ser240 in RPS6. Finally, this antibody was used to follow TOR activity in plants. Our results thus uncover a multi-level regulation of plant ribosomal genes and proteins by the TOR kinase.
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Affiliation(s)
- Thomas Dobrenel
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-SaclayVersailles, France
- Université Paris-Sud–Université Paris-SaclayOrsay, France
- Umeå Plant Science Center, Department of Plant Physiology, Umeå UniversityUmeå, Sweden
| | - Eder Mancera-Martínez
- Institut de Biologie Moléculaire des Plantes, UPR 2357 CNRS, Université de StrasbourgStrasbourg, France
| | - Céline Forzani
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-SaclayVersailles, France
| | - Marianne Azzopardi
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-SaclayVersailles, France
| | | | - Manon Moreau
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-SaclayVersailles, France
- Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, DSV, IBEB, SBVME, CEA, CNRS, Aix-Marseille Université, Faculté des Sciences de LuminyMarseille, France
| | - Mikhail Schepetilnikov
- Institut de Biologie Moléculaire des Plantes, UPR 2357 CNRS, Université de StrasbourgStrasbourg, France
| | - Johana Chicher
- Plateforme Protéomique Strasbourg-Esplanade, CNRS FRC1589, Institut de Biologie Moléculaire et CellulaireStrasbourg, France
| | | | - Michel Zivy
- Plateforme PAPPSO, UMR GQE-Le MoulonGif sur Yvette, France
| | - Christophe Robaglia
- Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, DSV, IBEB, SBVME, CEA, CNRS, Aix-Marseille Université, Faculté des Sciences de LuminyMarseille, France
| | - Lyubov A. Ryabova
- Institut de Biologie Moléculaire des Plantes, UPR 2357 CNRS, Université de StrasbourgStrasbourg, France
| | - Johannes Hanson
- Umeå Plant Science Center, Department of Plant Physiology, Umeå UniversityUmeå, Sweden
| | - Christian Meyer
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-SaclayVersailles, France
- *Correspondence: Christian Meyer,
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Xiong F, Dong P, Liu M, Xie G, Wang K, Zhuo F, Feng L, Yang L, Li Z, Ren M. Tomato FK506 Binding Protein 12KD (FKBP12) Mediates the Interaction between Rapamycin and Target of Rapamycin (TOR). FRONTIERS IN PLANT SCIENCE 2016; 7:1746. [PMID: 27917191 PMCID: PMC5114585 DOI: 10.3389/fpls.2016.01746] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/04/2016] [Indexed: 05/18/2023]
Abstract
Target of Rapamycin (TOR) signaling is an important regulator in multiple organisms including yeast, plants, and animals. However, the TOR signaling in plants is much less understood as compared to that in yeast and animals. TOR kinase can be efficiently suppressed by rapamycin in the presence of functional FK506 Binding Protein 12 KD (FKBP12) in yeast and animals. In most examined higher plants rapamycin fails to inhibit TOR kinase due to the non-functional FKBP12. Here we find that tomato plants showed obvious growth inhibition when treated with rapamycin and the inhibitory phenotype is similar to suppression of TOR causing by active-site TOR inhibitors (asTORis) such as KU63794, AZD8055, and Torin1. The chemical genetic assays using TOR inhibitors and heterologous expressing SlFKBP12 in Arabidopsis indicated that the TOR signaling is functional in tomato. The protein gel shifting and TOR inhibitors combination assays showed that SlFKBP12 can mediate the interaction between rapamycin and TOR. Furthermore, comparative expression profile analysis between treatments with rapamycin and KU63794 identified highly overlapped Differentially Expressed Genes (DEGs) which are involved in many anabolic and catabolic processes, such as photosynthesis, cell wall restructuring, and senescence in tomato. These observations suggest that SlFFBP12 is functional in tomato. The results provided basic information of TOR signaling in tomato, and also some new insights into how TOR controls plant growth and development through reprogramming the transcription profiles.
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Affiliation(s)
- Fangjie Xiong
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Pan Dong
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Mei Liu
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Gengxin Xie
- Center of Space Exploration, Ministry of EducationChongqing, China
| | - Kai Wang
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Fengping Zhuo
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Li Feng
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Lu Yang
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Zhengguo Li
- School of Life Sciences, Chongqing UniversityChongqing, China
- *Correspondence: Zhengguo Li
| | - Maozhi Ren
- School of Life Sciences, Chongqing UniversityChongqing, China
- Center of Space Exploration, Ministry of EducationChongqing, China
- Maozhi Ren
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Xiong Y, Sheen J. Novel links in the plant TOR kinase signaling network. CURRENT OPINION IN PLANT BIOLOGY 2015; 28:83-91. [PMID: 26476687 PMCID: PMC4612364 DOI: 10.1016/j.pbi.2015.09.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 09/18/2015] [Accepted: 09/25/2015] [Indexed: 05/18/2023]
Abstract
Nutrient and energy sensing and signaling mechanisms constitute the most ancient and fundamental regulatory networks to control growth and development in all life forms. The target of rapamycin (TOR) protein kinase is modulated by diverse nutrient, energy, hormone and stress inputs and plays a central role in regulating cell proliferation, growth, metabolism and stress responses from yeasts to plants and animals. Recent chemical, genetic, genomic and metabolomic analyses have enabled significant progress toward molecular understanding of the TOR signaling network in multicellular plants. This review discusses the applications of new chemical tools to probe plant TOR functions and highlights recent findings and predictions on TOR-mediate biological processes. Special focus is placed on novel and evolutionarily conserved TOR kinase effectors as positive and negative signaling regulators that control transcription, translation and metabolism to support cell proliferation, growth and maintenance from embryogenesis to senescence in the plant system.
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Affiliation(s)
- Yan Xiong
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai 200032, PR China
| | - Jen Sheen
- Department of Genetics, Harvard Medical School, USA; Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, MA 02114, USA.
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Imamura S, Kawase Y, Kobayashi I, Sone T, Era A, Miyagishima SY, Shimojima M, Ohta H, Tanaka K. Target of rapamycin (TOR) plays a critical role in triacylglycerol accumulation in microalgae. PLANT MOLECULAR BIOLOGY 2015; 89:309-18. [PMID: 26350402 DOI: 10.1007/s11103-015-0370-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/24/2015] [Indexed: 05/18/2023]
Abstract
Most microalgae produce triacylglycerol (TAG) under stress conditions such as nitrogen depletion, but the underlying molecular mechanism remains unclear. In this study, we focused on the role of target of rapamycin (TOR) in TAG accumulation. TOR is a serine/threonine protein kinase that is highly conserved and plays pivotal roles in nitrogen and other signaling pathways in eukaryotes. We previously constructed a rapamycin-susceptible Cyanidioschyzon merolae, a unicellular red alga, by expressing yeast FKBP12 protein to evaluate the results of TOR inhibition (Imamura et al. in Biochem Biophys Res Commun 439:264-269, 2013). By using this strain, we here report that rapamycin-induced TOR inhibition results in accumulation of cytoplasmic lipid droplets containing TAG. Transcripts for TAG synthesis-related genes, such as glycerol-3-phosphate acyltransferase and acyl-CoA:diacylglycerol acyltransferase (DGAT), were increased by rapamycin treatment. We also found that fatty acid synthase-dependent de novo fatty acid synthesis was required for the accumulation of lipid droplets. Induction of TAG and up-regulation of DGAT gene expression by rapamycin were similarly observed in the unicellular green alga, Chlamydomonas reinhardtii. These results suggest the general involvement of TOR signaling in TAG accumulation in divergent microalgae.
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Affiliation(s)
- Sousuke Imamura
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan.
| | - Yasuko Kawase
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Ikki Kobayashi
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Toshiyuki Sone
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Atsuko Era
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
- Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Shin-Ya Miyagishima
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
- Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Mie Shimojima
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B1 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
| | - Hiroyuki Ohta
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B1 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Kan Tanaka
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan.
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Spatial Regulation of Root Growth: Placing the Plant TOR Pathway in a Developmental Perspective. Int J Mol Sci 2015; 16:19671-97. [PMID: 26295391 PMCID: PMC4581319 DOI: 10.3390/ijms160819671] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 07/11/2015] [Accepted: 08/11/2015] [Indexed: 12/30/2022] Open
Abstract
Plant cells contain specialized structures, such as a cell wall and a large vacuole, which play a major role in cell growth. Roots follow an organized pattern of development, making them the organs of choice for studying the spatio-temporal regulation of cell proliferation and growth in plants. During root growth, cells originate from the initials surrounding the quiescent center, proliferate in the division zone of the meristem, and then increase in length in the elongation zone, reaching their final size and differentiation stage in the mature zone. Phytohormones, especially auxins and cytokinins, control the dynamic balance between cell division and differentiation and therefore organ size. Plant growth is also regulated by metabolites and nutrients, such as the sugars produced by photosynthesis or nitrate assimilated from the soil. Recent literature has shown that the conserved eukaryotic TOR (target of rapamycin) kinase pathway plays an important role in orchestrating plant growth. We will summarize how the regulation of cell proliferation and cell expansion by phytohormones are at the heart of root growth and then discuss recent data indicating that the TOR pathway integrates hormonal and nutritive signals to orchestrate root growth.
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Reitz MU, Gifford ML, Schäfer P. Hormone activities and the cell cycle machinery in immunity-triggered growth inhibition. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2187-97. [PMID: 25821072 PMCID: PMC4986725 DOI: 10.1093/jxb/erv106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 02/09/2015] [Accepted: 02/19/2015] [Indexed: 05/27/2023]
Abstract
Biotic stress and diseases caused by pathogen attack pose threats in crop production and significantly reduce crop yields. Enhancing immunity against pathogens is therefore of outstanding importance in crop breeding. However, this must be balanced, as immune activation inhibits plant growth. This immunity-coupled growth trade-off does not support resistance but is postulated to reflect the reallocation of resources to drive immunity. There is, however, increasing evidence that growth-immunity trade-offs are based on the reconfiguration of hormone pathways, shared by growth and immunity signalling. Studies in roots revealed the role of hormones in orchestrating growth across different cell types, with some hormones showing a defined cell type-specific activity. This is apparently highly relevant for the regulation of the cell cycle machinery and might be part of the growth-immunity cross-talk. Since plants are constantly exposed to Immuno-activating microbes under agricultural conditions, the transition from a growth to an immunity operating mode can significantly reduce crop yield and can conflict our efforts to generate next-generation crops with improved yield under climate change conditions. By focusing on roots, we outline the current knowledge of hormone signalling on the cell cycle machinery to explain growth trade-offs induced by immunity. By referring to abiotic stress studies, we further introduce how root cell type-specific hormone activities might contribute to growth under immunity and discuss the feasibility of uncoupling the growth-immunity cross-talk.
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Affiliation(s)
- M U Reitz
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - M L Gifford
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - P Schäfer
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
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Appel HM, Fescemyer H, Ehlting J, Weston D, Rehrig E, Joshi T, Xu D, Bohlmann J, Schultz J. Transcriptional responses of Arabidopsis thaliana to chewing and sucking insect herbivores. FRONTIERS IN PLANT SCIENCE 2014; 5:565. [PMID: 25452759 PMCID: PMC4231836 DOI: 10.3389/fpls.2014.00565] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 10/01/2014] [Indexed: 05/22/2023]
Abstract
We tested the hypothesis that Arabidopsis can recognize and respond differentially to insect species at the transcriptional level using a genome wide microarray. Transcriptional reprogramming was characterized using co-expression analysis in damaged and undamaged leaves at two times in response to mechanical wounding and four insect species. In all, 2778 (10.6%) of annotated genes on the array were differentially expressed in at least one treatment. Responses differed mainly between aphid and caterpillar and sampling times. Responses to aphids and caterpillars shared only 10% of up-regulated and 8% of down-regulated genes. Responses to two caterpillars shared 21 and 12% of up- and down-regulated genes, whereas responses to the two aphids shared only 7 and 4% of up-regulated and down-regulated genes. Overlap in genes expressed between 6 and 24 h was 3-15%, and depended on the insect species. Responses in attacked and unattacked leaves differed at 6 h but converged by 24 h. Genes responding to the insects are also responsive to many stressors and included primary metabolism. Aphids down-regulated amino acid catabolism; caterpillars stimulated production of amino acids involved in glucosinolate synthesis. Co-expression analysis revealed 17 response networks. Transcription factors were a major portion of differentially expressed genes throughout and responsive genes shared most of the known or postulated binding sites. However, cis-element composition of genes down regulated by the aphid M. persicae was unique, as were those of genes down-regulated by caterpillars. As many as 20 cis-elements were over-represented in one or more treatments, including some from well-characterized classes and others as yet uncharacterized. We suggest that transcriptional changes elicited by wounding and insects are heavily influenced by transcription factors and involve both enrichment of a common set of cis-elements and a unique enrichment of a few cis-elements in responding genes.
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Affiliation(s)
- Heidi M. Appel
- Bond Life Sciences Center and Division of Plant Sciences, University of MissouriColumbia, MO, USA
| | - Howard Fescemyer
- Department of Biology, The Pennsylvania State UniversityUniversity Park, PA, USA
| | - Juergen Ehlting
- Michael Smith Laboratories, University of British ColumbiaVancouver, BC, Canada
- Department of Biology, University of VictoriaVictoria, BC, Canada
| | - David Weston
- Biosciences Division, Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Erin Rehrig
- Biology and Chemistry Department, Fitchburg State UniversityFitchburg, MA, USA
| | - Trupti Joshi
- Department of Computer Science, Bond Life Sciences Center, Informatics Institute, University of MissouriColumbia, MO, USA
| | - Dong Xu
- Department of Computer Science, Bond Life Sciences Center, Informatics Institute, University of MissouriColumbia, MO, USA
| | - Joerg Bohlmann
- Michael Smith Laboratories, University of British ColumbiaVancouver, BC, Canada
| | - Jack Schultz
- Bond Life Sciences Center and Division of Plant Sciences, University of MissouriColumbia, MO, USA
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50
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Scofield S, Jones A, Murray JAH. The plant cell cycle in context. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2557-62. [PMID: 25025122 DOI: 10.1093/jxb/eru188] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
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