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Hu Z, Zhang N, Qin Z, Li J, Yang N, Chen Y, Kong J, Luo W, Xiong A, Zhuang J. Differential Response of MYB Transcription Factor Gene Transcripts to Circadian Rhythm in Tea Plants ( Camellia sinensis). Int J Mol Sci 2024; 25:657. [PMID: 38203827 PMCID: PMC10780195 DOI: 10.3390/ijms25010657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 12/31/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024] Open
Abstract
The circadian clock refers to the formation of a certain rule in the long-term evolution of an organism, which is an invisible 'clock' in the body of an organism. As one of the largest TF families in higher plants, the MYB transcription factor is involved in plant growth and development. MYB is also inextricably correlated with the circadian rhythm. In this study, the transcriptome data of the tea plant 'Baiyeyihao' were measured at a photoperiod interval of 4 h (24 h). A total of 25,306 unigenes were obtained, including 14,615 unigenes that were annotated across 20 functional categories within the GO classification. Additionally, 10,443 single-gene clusters were annotated to 11 sublevels of metabolic pathways using KEGG. Based on the results of gene annotation and differential gene transcript analysis, 22 genes encoding MYB transcription factors were identified. The G10 group in the phylogenetic tree had 13 members, of which 5 were related to the circadian rhythm, accounting for 39%. The G1, G2, G8, G9, G15, G16, G18, G19, G20, G21 and G23 groups had no members associated with the circadian rhythm. Among the 22 differentially expressed MYB transcription factors, 3 members of LHY, RVE1 and RVE8 were core circadian rhythm genes belonging to the G10, G12 and G10 groups, respectively. Real-time fluorescence quantitative PCR was used to detect and validate the expression of the gene transcripts encoding MYB transcription factors associated with the circadian rhythm.
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Affiliation(s)
- Zhihang Hu
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China;
| | - Nan Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China;
| | - Zhiyuan Qin
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
| | - Jinwen Li
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
| | - Ni Yang
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
| | - Yi Chen
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
| | - Jieyu Kong
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
| | - Wei Luo
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
| | - Aisheng Xiong
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China;
| | - Jing Zhuang
- Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (Z.H.); (Z.Q.); (J.L.); (N.Y.); (Y.C.); (J.K.); (W.L.)
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2
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James AB, Sharples C, Laird J, Armstrong EM, Guo W, Tzioutziou N, Zhang R, Brown JWS, Nimmo HG, Jones MA. REVEILLE2 thermosensitive splicing: a molecular basis for the integration of nocturnal temperature information by the Arabidopsis circadian clock. THE NEW PHYTOLOGIST 2024; 241:283-297. [PMID: 37897048 DOI: 10.1111/nph.19339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023]
Abstract
Cold stress is one of the major environmental factors that limit growth and yield of plants. However, it is still not fully understood how plants account for daily temperature fluctuations, nor how these temperature changes are integrated with other regulatory systems such as the circadian clock. We demonstrate that REVEILLE2 undergoes alternative splicing after chilling that increases accumulation of a transcript isoform encoding a MYB-like transcription factor. We explore the biological function of REVEILLE2 in Arabidopsis thaliana using a combination of molecular genetics, transcriptomics, and physiology. Disruption of REVEILLE2 alternative splicing alters regulatory gene expression, impairs circadian timing, and improves photosynthetic capacity. Changes in nuclear gene expression are particularly apparent in the initial hours following chilling, with chloroplast gene expression subsequently upregulated. The response of REVEILLE2 to chilling extends our understanding of plants immediate response to cooling. We propose that the circadian component REVEILLE2 restricts plants responses to nocturnal reductions in temperature, thereby enabling appropriate responses to daily environmental changes.
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Affiliation(s)
- Allan B James
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Chantal Sharples
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
- RNA Biology and Molecular Physiology, Faculty for Biology, Bielefeld University, Universitaetsstrasse 25, 33615, Bielefeld, Germany
| | - Janet Laird
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Emily May Armstrong
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Wenbin Guo
- Information and Computational Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Nikoleta Tzioutziou
- Plant Sciences Division, College of Life Sciences, University of Dundee, Invergowrie, Dundee, DD2 5DA, UK
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Runxuan Zhang
- Information and Computational Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - John W S Brown
- Plant Sciences Division, College of Life Sciences, University of Dundee, Invergowrie, Dundee, DD2 5DA, UK
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Hugh G Nimmo
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Matthew A Jones
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
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3
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Borba AR, Reyna-Llorens I, Dickinson PJ, Steed G, Gouveia P, Górska AM, Gomes C, Kromdijk J, Webb AAR, Saibo NJM, Hibberd JM. Compartmentation of photosynthesis gene expression in C4 maize depends on time of day. PLANT PHYSIOLOGY 2023; 193:2306-2320. [PMID: 37555432 PMCID: PMC10663113 DOI: 10.1093/plphys/kiad447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/29/2023] [Accepted: 07/13/2023] [Indexed: 08/10/2023]
Abstract
Compared with the ancestral C3 state, C4 photosynthesis occurs at higher rates with improved water and nitrogen use efficiencies. In both C3 and C4 plants, rates of photosynthesis increase with light intensity and are maximal around midday. We determined that in the absence of light or temperature fluctuations, photosynthesis in maize (Zea mays) peaks in the middle of the subjective photoperiod. To investigate the molecular processes associated with these temporal changes, we performed RNA sequencing of maize mesophyll and bundle sheath strands over a 24-h time course. Preferential expression of C4 cycle genes in these cell types was strongest between 6 and 10 h after dawn when rates of photosynthesis were highest. For the bundle sheath, DNA motif enrichment and gene coexpression analyses suggested members of the DNA binding with one finger (DOF) and MADS (MINICHROMOSOME MAINTENANCE FACTOR 1/AGAMOUS/DEFICIENS/Serum Response Factor)-domain transcription factor families mediate diurnal fluctuations in C4 gene expression, while trans-activation assays in planta confirmed their ability to activate promoter fragments from bundle sheath expressed genes. The work thus identifies transcriptional regulators and peaks in cell-specific C4 gene expression coincident with maximum rates of photosynthesis in the maize leaf at midday.
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Affiliation(s)
- Ana Rita Borba
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras 2780-157, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras 2780-157, Portugal
| | - Ivan Reyna-Llorens
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Patrick J Dickinson
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Gareth Steed
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Paulo Gouveia
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras 2780-157, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras 2780-157, Portugal
| | - Alicja M Górska
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras 2780-157, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras 2780-157, Portugal
| | - Celia Gomes
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras 2780-157, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras 2780-157, Portugal
| | - Johannes Kromdijk
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Alex A R Webb
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Nelson J M Saibo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras 2780-157, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras 2780-157, Portugal
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
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Prasetyaningrum P, Litthauer S, Vegliani F, Battle MW, Wood MW, Liu X, Dickson C, Jones MA. Inhibition of RNA degradation integrates the metabolic signals induced by osmotic stress into the Arabidopsis circadian system. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5805-5819. [PMID: 37453132 PMCID: PMC10540740 DOI: 10.1093/jxb/erad274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023]
Abstract
The circadian clock system acts as an endogenous timing reference that coordinates many metabolic and physiological processes in plants. Previous studies have shown that the application of osmotic stress delays circadian rhythms via 3'-phospho-adenosine 5'-phosphate (PAP), a retrograde signalling metabolite that is produced in response to redox stress within organelles. PAP accumulation leads to the inhibition of exoribonucleases (XRNs), which are responsible for RNA degradation. Interestingly, we are now able to demonstrate that post-transcriptional processing is crucial for the circadian response to osmotic stress. Our data show that osmotic stress increases the stability of specific circadian RNAs, suggesting that RNA metabolism plays a vital role in circadian clock coordination during drought. Inactivation of XRN4 is sufficient to extend circadian rhythms as part of this response, with PRR7 and LWD1 identified as transcripts that are post-transcriptionally regulated to delay circadian progression.
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Affiliation(s)
| | | | - Franco Vegliani
- School of Molecular Biosciences, University of Glasgow, Glasgow G12 8QQ, UK
| | | | | | - Xinmeng Liu
- School of Molecular Biosciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Cathryn Dickson
- School of Molecular Biosciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Matthew Alan Jones
- School of Molecular Biosciences, University of Glasgow, Glasgow G12 8QQ, UK
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5
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Xu H, Wang X, Wei J, Zuo Y, Wang L. The Regulatory Networks of the Circadian Clock Involved in Plant Adaptation and Crop Yield. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12091897. [PMID: 37176955 PMCID: PMC10181312 DOI: 10.3390/plants12091897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023]
Abstract
Global climatic change increasingly threatens plant adaptation and crop yields. By synchronizing internal biological processes, including photosynthesis, metabolism, and responses to biotic and abiotic stress, with external environmental cures, such as light and temperature, the circadian clock benefits plant adaptation and crop yield. In this review, we focus on the multiple levels of interaction between the plant circadian clock and environmental factors, and we summarize recent progresses on how the circadian clock affects yield. In addition, we propose potential strategies for better utilizing the current knowledge of circadian biology in crop production in the future.
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Affiliation(s)
- Hang Xu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiling Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Wei
- College of Life Sciences, Changchun Normal University, Changchun 130032, China
| | - Yi Zuo
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Lei Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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6
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Chen Q, Qu M, Chen Q, Meng X, Fan H. Phosphoproteomics analysis of the effect of target of rapamycin kinase inhibition on Cucumis sativus in response to Podosphaera xanthii. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 197:107641. [PMID: 36940522 DOI: 10.1016/j.plaphy.2023.107641] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/12/2023] [Accepted: 03/13/2023] [Indexed: 06/18/2023]
Abstract
Target of rapamycin (TOR) kinase is a conserved sensor of cell growth in yeasts, plants, and mammals. Despite the extensive research on the TOR complex in various biological processes, large-scale phosphoproteomics analysis of TOR phosphorylation events upon environmental stress are scarce. Powdery mildew caused by Podosphaera xanthii poses a major threat to the quality and yield of cucumber (Cucumis sativus L.). Previous studies concluded that TOR participated in abiotic and biotic stress responses. Hence, studying the underlying mechanism of TOR-P. xanthii infection is particularly important. In this study, we performed a quantitative phosphoproteomics studies of Cucumis against P. xanthii attack under AZD-8055 (TOR inhibitor) pretreatment. A total of 3384 phosphopeptides were identified from the 1699 phosphoproteins. The Motif-X analysis showed high sensitivity and specificity of serine sites under AZD-8055-treatment or P. xanthii stress, and TOR exhibited a unique preference for proline at +1 position and glycine at -1 position to enhance the phosphorylation response to P. xanthii. The functional analysis suggested that the unique responses were attributed to proteins related to plant hormone signaling, mitogen-activated protein kinase cascade signaling, phosphatidylinositol signaling system, and circadian rhythm; and calcium signaling- and defense response-related proteins. Our results provided rich resources for understanding the molecular mechanism of how the TOR kinase controlled plant growth and stress adaptation.
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Affiliation(s)
- Qiumin Chen
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
| | - Mengqi Qu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, China
| | - Qinglei Chen
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, China
| | - Xiangnan Meng
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Biology and Genetic Improvement of Fruit Vegetables of Shenyang, Shenyang Agricultural University, Shenyang, 110866, China.
| | - Haiyan Fan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Biology and Genetic Improvement of Fruit Vegetables of Shenyang, Shenyang Agricultural University, Shenyang, 110866, China.
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7
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Aros-Mualin D, Guadagno CR, Silvestro D, Kessler M. Light, rather than circadian rhythm, regulates gas exchange in ferns and lycophytes. PLANT PHYSIOLOGY 2023; 191:1634-1647. [PMID: 36691320 PMCID: PMC10022864 DOI: 10.1093/plphys/kiad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Circadian regulation plays a vital role in optimizing plant responses to the environment. However, while circadian regulation has been extensively studied in angiosperms, very little is known for lycophytes and ferns, leaving a gap in our understanding of the evolution of circadian rhythms across the plant kingdom. Here, we investigated circadian regulation in gas exchange through stomatal conductance and photosynthetic efficiency in a phylogenetically broad panel of 21 species of lycophytes and ferns over a 46 h period under constant light and a selected few under more natural conditions with day-night cycles. No rhythm was detected under constant light for either lycophytes or ferns, except for two semi-aquatic species of the family Marsileaceae (Marsilea azorica and Regnellidium diphyllum), which showed rhythms in stomatal conductance. Furthermore, these results indicated the presence of a light-driven stomatal control for ferns and lycophytes, with a possible passive fine-tuning through leaf water status adjustments. These findings support previous evidence for the fundamentally different regulation of gas exchange in lycophytes and ferns compared to angiosperms, and they suggest the presence of alternative stomatal regulations in Marsileaceae, an aquatic family already well known for numerous other distinctive physiological traits. Overall, our study provides evidence for heterogeneous circadian regulation across plant lineages, highlighting the importance of broad taxonomic scope in comparative plant physiology studies.
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Affiliation(s)
| | | | - Daniele Silvestro
- Department of Biology, University of Fribourg, Fribourg 1700, Switzerland
- Department of Biological and Environmental Sciences and Global Gothenburg Biodiversity Centre, University of Gothenburg, Gothenburg SE-405 30, Sweden
- Swiss Institute of Bioinformatics, Fribourg 1700, Switzerland
| | - Michael Kessler
- Department of Systematics and Evolutionary Botany, University of Zurich, Zurich 8008, Switzerland
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8
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Cuitun‐Coronado D, Rees H, Colmer J, Hall A, de Barros Dantas LL, Dodd AN. Circadian and diel regulation of photosynthesis in the bryophyte Marchantia polymorpha. PLANT, CELL & ENVIRONMENT 2022; 45:2381-2394. [PMID: 35611455 PMCID: PMC9546472 DOI: 10.1111/pce.14364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/20/2022] [Accepted: 05/21/2022] [Indexed: 05/10/2023]
Abstract
Circadian rhythms are 24-h biological cycles that align metabolism, physiology, and development with daily environmental fluctuations. Photosynthetic processes are governed by the circadian clock in both flowering plants and some cyanobacteria, but it is unclear how extensively this is conserved throughout the green lineage. We investigated the contribution of circadian regulation to aspects of photosynthesis in Marchantia polymorpha, a liverwort that diverged from flowering plants early in the evolution of land plants. First, we identified in M. polymorpha the circadian regulation of photosynthetic biochemistry, measured using two approaches (delayed fluorescence, pulse amplitude modulation fluorescence). Second, we identified that light-dark cycles synchronize the phase of 24 h cycles of photosynthesis in M. polymorpha, whereas the phases of different thalli desynchronize under free-running conditions. This might also be due to the masking of the underlying circadian rhythms of photosynthesis by light-dark cycles. Finally, we used a pharmacological approach to identify that chloroplast translation might be necessary for clock control of light-harvesting in M. polymorpha. We infer that the circadian regulation of photosynthesis is well-conserved amongst terrestrial plants.
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Affiliation(s)
- David Cuitun‐Coronado
- Department of Cell and Developmental BiologyJohn Innes CentreNorwichUK
- School of Biological SciencesUniversity of BristolBristolUK
| | | | | | | | | | - Antony N. Dodd
- Department of Cell and Developmental BiologyJohn Innes CentreNorwichUK
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9
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Regulatory Role of Circadian Clocks on ABA Production and Signaling, Stomatal Responses, and Water-Use Efficiency under Water-Deficit Conditions. Cells 2022; 11:cells11071154. [PMID: 35406719 PMCID: PMC8997731 DOI: 10.3390/cells11071154] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/15/2022] [Accepted: 03/25/2022] [Indexed: 02/04/2023] Open
Abstract
Plants deploy molecular, physiological, and anatomical adaptations to cope with long-term water-deficit exposure, and some of these processes are controlled by circadian clocks. Circadian clocks are endogenous timekeepers that autonomously modulate biological systems over the course of the day–night cycle. Plants’ responses to water deficiency vary with the time of the day. Opening and closing of stomata, which control water loss from plants, have diurnal responses based on the humidity level in the rhizosphere and the air surrounding the leaves. Abscisic acid (ABA), the main phytohormone modulating the stomatal response to water availability, is regulated by circadian clocks. The molecular mechanism of the plant’s circadian clock for regulating stress responses is composed not only of transcriptional but also posttranscriptional regulatory networks. Despite the importance of regulatory impact of circadian clock systems on ABA production and signaling, which is reflected in stomatal responses and as a consequence influences the drought tolerance response of the plants, the interrelationship between circadian clock, ABA homeostasis, and signaling and water-deficit responses has to date not been clearly described. In this review, we hypothesized that the circadian clock through ABA directs plants to modulate their responses and feedback mechanisms to ensure survival and to enhance their fitness under drought conditions. Different regulatory pathways and challenges in circadian-based rhythms and the possible adaptive advantage through them are also discussed.
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10
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Greenwood M, Hall AJW, Locke JCW. High Spatial Resolution Luciferase Imaging of the Arabidopsis thaliana Circadian Clock. Methods Mol Biol 2022; 2398:47-55. [PMID: 34674166 DOI: 10.1007/978-1-0716-1912-4_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The A. thaliana circadian clock is an example of a gene network that generates rich temporal and spatial dynamics. Bioluminescent imaging has proven a powerful method to help dissect the genetic mechanisms that generate oscillations of gene expression over the course of the day. However, its use for the study of spatial regulation is often limited by resolution. Here, we describe a modified luciferase imaging method for the study of the Arabidopsis circadian clock across the plant at sub-tissue-level resolution.
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Affiliation(s)
- Mark Greenwood
- Sainsbury Laboratory, University of Cambridge, Cambridge, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | - James C W Locke
- Sainsbury Laboratory, University of Cambridge, Cambridge, UK.
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11
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Agrobacterium-Mediated Seedling Transformation to Measure Circadian Rhythms in Arabidopsis. Methods Mol Biol 2022; 2398:57-64. [PMID: 34674167 DOI: 10.1007/978-1-0716-1912-4_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Circadian clocks are endogenous timing mechanisms that allow an organism to adapt cellular processes in anticipation of predictable changes in the environment. Luciferase reporters are well utilized as an effective, nondestructive method to measure circadian rhythms of promoter activity in Arabidopsis. Obtaining stable transgenic reporter lines can be laborious. Here, we report a protocol for Agrobacterium-mediated seedling transformation tailored for plant circadian studies. We show that period estimates generated from wild-type and clock-mutant seedlings transformed with circadian luciferase reporters are similar to rhythms obtained from equivalent stable transgenic seedlings. These experiments demonstrate the versatility and robustness of the protocol for testing new constructs or quickly assessing circadian effects in any genotype of interest.
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12
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Detection and Analysis of Circadian Rhythms Via Prompt Chlorophyll Fluorescence. Methods Mol Biol 2021. [PMID: 34674165 DOI: 10.1007/978-1-0716-1912-4_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Monitoring prompt chlorophyll fluorescence (F) by making consecutive pulse amplitude modulation (PAM) measurements is a noninvasive, nondestructive, potentially high-throughput technique for evaluating circadian rhythms in diverse plant species. The technique is also less labor-intensive than many others currently used and requires no transgenic procedures.
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13
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Coordinative regulation of plants growth and development by light and circadian clock. ABIOTECH 2021; 2:176-189. [PMID: 36304756 PMCID: PMC9590570 DOI: 10.1007/s42994-021-00041-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/13/2021] [Indexed: 11/30/2022]
Abstract
The circadian clock, known as an endogenous timekeeping system, can integrate various cues to regulate plant physiological functions for adapting to the changing environment and thus ensure optimal plant growth. The synchronization of internal clock with external environmental information needs a process termed entrainment, and light is one of the predominant entraining signals for the plant circadian clock. Photoreceptors can detect and transmit light information to the clock core oscillator through transcriptional or post-transcriptional interactions with core-clock components to sustain circadian rhythms and regulate a myriad of downstream responses, including photomorphogenesis and photoperiodic flowering which are key links in the process of growth and development. Here we summarize the current understanding of the molecular network of the circadian clock and how light information is integrated into the circadian system, especially focus on how the circadian clock and light signals coordinately regulate the common downstream outputs. We discuss the functions of the clock and light signals in regulating photoperiodic flowering among various crop species.
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14
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Singh RK, Bhalerao RP, Eriksson ME. Growing in time: exploring the molecular mechanisms of tree growth. TREE PHYSIOLOGY 2021; 41:657-678. [PMID: 32470114 PMCID: PMC8033248 DOI: 10.1093/treephys/tpaa065] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/31/2020] [Accepted: 05/27/2020] [Indexed: 05/31/2023]
Abstract
Trees cover vast areas of the Earth's landmasses. They mitigate erosion, capture carbon dioxide, produce oxygen and support biodiversity, and also are a source of food, raw materials and energy for human populations. Understanding the growth cycles of trees is fundamental for many areas of research. Trees, like most other organisms, have evolved a circadian clock to synchronize their growth and development with the daily and seasonal cycles of the environment. These regular changes in light, daylength and temperature are perceived via a range of dedicated receptors and cause resetting of the circadian clock to local time. This allows anticipation of daily and seasonal fluctuations and enables trees to co-ordinate their metabolism and physiology to ensure vital processes occur at the optimal times. In this review, we explore the current state of knowledge concerning the regulation of growth and seasonal dormancy in trees, using information drawn from model systems such as Populus spp.
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Affiliation(s)
- Rajesh Kumar Singh
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå SE-901 87, Sweden
| | - Rishikesh P Bhalerao
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå SE-901 82, Sweden
| | - Maria E Eriksson
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå SE-901 87, Sweden
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15
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Eckstein A, Grzyb J, Hermanowicz P, Zgłobicki P, Łabuz J, Strzałka W, Dziga D, Banaś AK. Arabidopsis Phototropins Participate in the Regulation of Dark-Induced Leaf Senescence. Int J Mol Sci 2021; 22:ijms22041836. [PMID: 33673252 PMCID: PMC7918785 DOI: 10.3390/ijms22041836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/09/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
Senescence is the final stage of plant development, affecting individual organs or the whole organism, and it can be induced by several environmental factors, including shading or darkness. Although inevitable, senescence is a complex and tightly regulated process, ensuring optimal remobilization of nutrients and cellular components from senescing organs. Photoreceptors such as phytochromes and cryptochromes are known to participate in the process of senescence, but the involvement of phototropins has not been studied to date. We investigated the role of these blue light photoreceptors in the senescence of individually darkened Arabidopsis thaliana leaves. We compared several physiological and molecular senescence markers in darkened leaves of wild-type plants and phototropin mutants (phot1, phot2, and phot1phot2). In general, all the symptoms of senescence (lower photochemical activity of photosystem II, photosynthetic pigment degradation, down-regulation of photosynthetic genes, and up-regulation of senescence-associated genes) were less pronounced in phot1phot2, as compared to the wild type, and some also in one of the single mutants, indicating delayed senescence. This points to different mechanisms of phototropin operation in the regulation of senescence-associated processes, either with both photoreceptors acting redundantly, or only one of them, phot1, playing a dominant role.
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Affiliation(s)
- Aleksandra Eckstein
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
- Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Joanna Grzyb
- Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland;
| | - Paweł Hermanowicz
- Laboratory of Photobiology, The Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland; (P.H.); (J.Ł.)
| | - Piotr Zgłobicki
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
| | - Justyna Łabuz
- Laboratory of Photobiology, The Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland; (P.H.); (J.Ł.)
| | - Wojciech Strzałka
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
| | - Dariusz Dziga
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland;
| | - Agnieszka Katarzyna Banaś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
- Correspondence:
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16
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Djerrab D, Bertrand B, Breitler JC, Léran S, Dechamp E, Campa C, Barrachina C, Conejero G, Etienne H, Sulpice R. Photoperiod-dependent transcriptional modifications in key metabolic pathways in Coffea arabica. TREE PHYSIOLOGY 2021; 41:302-316. [PMID: 33080620 PMCID: PMC7874067 DOI: 10.1093/treephys/tpaa130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 07/20/2020] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
Photoperiod length induces in temperate plants major changes in growth rates, morphology and metabolism with, for example, modifications in the partitioning of photosynthates to avoid starvation at the end of long nights. However, this has never been studied for a tropical perennial species adapted to grow in a natural photoperiod close to 12 h/12 h all year long. We grew Coffea arabica L., an understorey perennial evergreen tropical species in its natural 12 h/12 h and in a short 8 h/16 h photoperiod, and we investigated its responses at the physiological, metabolic and transcriptomic levels. The expression pattern of rhythmic genes, including core clock genes, was affected by changes in photoperiod. Overall, we identified 2859 rhythmic genes, of which 89% were also rhythmic in Arabidopsis thaliana L. Under short-days, plant growth was reduced, and leaves were thinner with lower chlorophyll content. In addition, secondary metabolism was also affected with chlorogenic acid and epicatechin levels decreasing, and in agreement, the genes involved in lignin synthesis were overexpressed and those involved in the flavanol pathway were underexpressed. Our results show that the 8 h/16 h photoperiod induces drastic changes in morphology, metabolites and gene expression, and the responses for gene expression are similar to those observed in the temperate annual A. thaliana species. Short photoperiod induces drastic changes in gene expression, metabolites and leaf structure, some of these responses being similar to those observed in A. thaliana.
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Affiliation(s)
- Doâa Djerrab
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR IPME, F-34398 Montpellier, France
- UMR IPME, Université de Montpellier, CIRAD, IRD, F-34398 Montpellier, France
| | | | - Jean-Christophe Breitler
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR IPME, F-34398 Montpellier, France
- UMR IPME, Université de Montpellier, CIRAD, IRD, F-34398 Montpellier, France
| | - Sophie Léran
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR IPME, F-34398 Montpellier, France
- UMR IPME, Université de Montpellier, CIRAD, IRD, F-34398 Montpellier, France
| | - Eveline Dechamp
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR IPME, F-34398 Montpellier, France
- UMR IPME, Université de Montpellier, CIRAD, IRD, F-34398 Montpellier, France
| | - Claudine Campa
- UMR IPME, Université de Montpellier, CIRAD, IRD, F-34398 Montpellier, France
- IRD, UMR IPME, F-34394 Montpellier, France
| | - Célia Barrachina
- MGX, Biocampus Montpellier, CNRS, INSERM, University of Montpellier, 34000 Montpellier, France
| | - Geneviève Conejero
- BPMP, University of Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, France
| | - Hervé Etienne
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR IPME, F-34398 Montpellier, France
- UMR IPME, Université de Montpellier, CIRAD, IRD, F-34398 Montpellier, France
| | - Ronan Sulpice
- National University of Ireland, Plant Systems Biology Lab, Ryan Institute, School of Natural Sciences, University Road, Galway H91 TK33, Ireland
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17
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Wang X, Xu Y, Zhou M, Wang W. Assessing Global Circadian Rhythm Through Single-Time-Point Transcriptomic Analysis. Methods Mol Biol 2021; 2328:215-225. [PMID: 34251629 DOI: 10.1007/978-1-0716-1534-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Plant circadian clock has emerged as a central hub integrating various endogenous signals and exogenous stimuli to coordinate diverse plant physiological processes. The intimate relationship between crop circadian clock and key agronomic traits has been increasingly appreciated. However, due to the lack of fundamental genetic resources, more complex genome structures and the high cost of large-scale time-course circadian expression profiling, our understanding of crop circadian clock is still very limited. To study plant circadian clock, conventional methods rely on time-course experiments, which can be expensive and time-consuming. Different from these conventional approaches, the molecular timetable method can estimate the global rhythm using single-time-point transcriptome datasets, which has shown great promises in accelerating studies of crop circadian clock. Here we describe the application of the molecular timetable method in soybean and provide key technical caveats as well as related R Markdown scripts.
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Affiliation(s)
- Xingwei Wang
- State Key Laboratory for Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
- Center for Life Sciences, Beijing, China
| | - Yufeng Xu
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Mian Zhou
- College of Life Sciences, Capital Normal University, Beijing, China.
| | - Wei Wang
- State Key Laboratory for Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.
- Center for Life Sciences, Beijing, China.
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18
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Farré EM. The brown clock: circadian rhythms in stramenopiles. PHYSIOLOGIA PLANTARUM 2020; 169:430-441. [PMID: 32274814 DOI: 10.1111/ppl.13104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
Circadian clocks allow organisms to anticipate environmental changes associated with the diurnal light/dark cycle. Circadian oscillators have been described in plants and green algae, cyanobacteria, animals and fungi, however, little is known about the circadian clocks of photosynthetic eukaryotes outside the green lineage. Stramenopiles are a diverse group of secondary endosymbionts whose plastid originated from a red alga. Photosynthetic stramenopiles, which include diatoms and brown algae, play key roles in biogeochemical cycles and are important components of marine ecosystems. Genome annotation efforts indicated the presence of a novel type of oscillator in these organisms and the first circadian clock component in a stramenopile has been recently discovered. This review summarizes the phenotypic characterization of circadian rhythms in stramenopiles and current efforts to determine the mechanisms of this 'brown clock'. The elucidation of this brown clock will enable a deeper understanding of the role of self-sustained oscillations in the adaptation to life in marine environments.
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Affiliation(s)
- Eva M Farré
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
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19
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Battle MW, Jones MA. Cryptochromes integrate green light signals into the circadian system. PLANT, CELL & ENVIRONMENT 2020; 43:16-27. [PMID: 31410859 PMCID: PMC6973147 DOI: 10.1111/pce.13643] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 05/04/2023]
Abstract
Plants are acutely sensitive of their light environment, adapting their growth habit and prioritizing developmental decisions to maximize fecundity. In addition to providing an energy source and directional information, light quality also contributes to entrainment of the circadian system, an endogenous timing mechanism that integrates endogenous and environmental signalling cues to promote growth. Whereas plants' perception of red and blue portions of the spectrum are well defined, green light sensitivity remains enigmatic. In this study, we show that low fluence rates of green light are sufficient to entrain and maintain circadian rhythms in Arabidopsis and that cryptochromes contribute to this response. Importantly, green light responses are distinguishable from low blue light-induced phenotypes. These data suggest a distinct signalling mechanism enables entrainment of the circadian system in green light-enriched environments, such as those found in undergrowth and in densely planted monoculture.
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Affiliation(s)
| | - Matthew Alan Jones
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
- Institute of Molecular, Cell and Systems BiologyUniversity of GlasgowGlasgowG12 8QQUK
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20
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Liu D, Chen M, Mendoza B, Cheng H, Hu R, Li L, Trinh CT, Tuskan GA, Yang X. CRISPR/Cas9-mediated targeted mutagenesis for functional genomics research of crassulacean acid metabolism plants. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6621-6629. [PMID: 31562521 PMCID: PMC6883263 DOI: 10.1093/jxb/erz415] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 08/29/2019] [Indexed: 05/17/2023]
Abstract
Crassulacean acid metabolism (CAM) is an important photosynthetic pathway in diverse lineages of plants featuring high water-use efficiency and drought tolerance. A big challenge facing the CAM research community is to understand the function of the annotated genes in CAM plant genomes. Recently, a new genome editing technology using CRISPR/Cas9 has become a more precise and powerful tool than traditional approaches for functional genomics research in C3 and C4 plants. In this study, we explore the potential of CRISPR/Cas9 to characterize the function of CAM-related genes in the model CAM species Kalanchoë fedtschenkoi. We demonstrate that CRISPR/Cas9 is effective in creating biallelic indel mutagenesis to reveal previously unknown roles of blue light receptor phototropin 2 (KfePHOT2) in the CAM pathway. Knocking out KfePHOT2 reduced stomatal conductance and CO2 fixation in late afternoon and increased stomatal conductance and CO2 fixation during the night, indicating that blue light signaling plays an important role in the CAM pathway. Lastly, we provide a genome-wide guide RNA database targeting 45 183 protein-coding transcripts annotated in the K. fedtschenkoi genome.
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Affiliation(s)
- Degao Liu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- DOE-Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Mei Chen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, China
| | - Brian Mendoza
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA
| | - Hua Cheng
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Rongbin Hu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Linling Li
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Cong T Trinh
- DOE-Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA
| | - Gerald A Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- DOE-Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Xiaohan Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- DOE-Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA
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21
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Cano-Ramirez DL, Saskia de Fraine T, Griffiths OG, Dodd AN. Photosynthesis and circadian rhythms regulate the buoyancy of marimo lake balls. Curr Biol 2019; 28:R869-R870. [PMID: 30130504 DOI: 10.1016/j.cub.2018.07.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Marimo are unusual, attractive and endangered spherical aggregations of the filamentous green macroalga Aegagropila linnaei (Figure 1A-E) [1]. Globally rare, marimo populations persist in cold freshwater lakes in Japan, Iceland and Ukraine. Marimo occupy both the lake bed and rise to the lake surface [2,3]. Here, we show that marimo buoyancy is conferred by bubbles arising from photosynthesis. We find that light-induced acquisition of buoyancy by marimo is circadian-regulated. We identify that there are circadian rhythms of photosynthesis in marimo, which might explain the circadian rhythm of buoyancy in response to light. This identifies a circadian-regulated buoyancy response in an intriguing and little-studied plant.
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Affiliation(s)
- Dora L Cano-Ramirez
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Tara Saskia de Fraine
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Olivia G Griffiths
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Antony N Dodd
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK.
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22
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Ronald J, Davis SJ. Focusing on the nuclear and subnuclear dynamics of light and circadian signalling. PLANT, CELL & ENVIRONMENT 2019; 42:2871-2884. [PMID: 31369151 DOI: 10.1111/pce.13634] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/27/2019] [Accepted: 07/30/2019] [Indexed: 05/22/2023]
Abstract
Circadian clocks provide organisms the ability to synchronize their internal physiological responses with the external environment. This process, termed entrainment, occurs through the perception of internal and external stimuli. As with other organisms, in plants, the perception of light is a critical for the entrainment and sustainment of circadian rhythms. Red, blue, far-red, and UV-B light are perceived by the oscillator through the activity of photoreceptors. Four classes of photoreceptors signal to the oscillator: phytochromes, cryptochromes, UVR8, and LOV-KELCH domain proteins. In most cases, these photoreceptors localize to the nucleus in response to light and can associate to subnuclear structures to initiate downstream signalling. In this review, we will highlight the recent advances made in understanding the mechanisms facilitating the nuclear and subnuclear localization of photoreceptors and the role these subnuclear bodies have in photoreceptor signalling, including to the oscillator. We will also highlight recent progress that has been made in understanding the regulation of the nuclear and subnuclear localization of components of the plant circadian clock.
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Affiliation(s)
- James Ronald
- Department of Biology, University of York, YO10 5DD, York, UK
| | - Seth J Davis
- Department of Biology, University of York, YO10 5DD, York, UK
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23
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Greenwood M, Domijan M, Gould PD, Hall AJW, Locke JCW. Coordinated circadian timing through the integration of local inputs in Arabidopsis thaliana. PLoS Biol 2019; 17:e3000407. [PMID: 31415556 PMCID: PMC6695092 DOI: 10.1371/journal.pbio.3000407] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/11/2019] [Indexed: 12/14/2022] Open
Abstract
Individual plant cells have a genetic circuit, the circadian clock, that times key processes to the day-night cycle. These clocks are aligned to the day-night cycle by multiple environmental signals that vary across the plant. How does the plant integrate clock rhythms, both within and between organs, to ensure coordinated timing? To address this question, we examined the clock at the sub-tissue level across Arabidopsis thaliana seedlings under multiple environmental conditions and genetic backgrounds. Our results show that the clock runs at different speeds (periods) in each organ, which causes the clock to peak at different times across the plant in both constant environmental conditions and light-dark (LD) cycles. Closer examination reveals that spatial waves of clock gene expression propagate both within and between organs. Using a combination of modeling and experiment, we reveal that these spatial waves are the result of the period differences between organs and local coupling, rather than long-distance signaling. With further experiments we show that the endogenous period differences, and thus the spatial waves, can be generated by the organ specificity of inputs into the clock. We demonstrate this by modulating periods using light and metabolic signals, as well as with genetic perturbations. Our results reveal that plant clocks can be set locally by organ-specific inputs but coordinated globally via spatial waves of clock gene expression.
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Affiliation(s)
- Mark Greenwood
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Mirela Domijan
- Department of Mathematical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Peter D. Gould
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | | | - James C. W. Locke
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
- Microsoft Research, Cambridge, United Kingdom
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24
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Brelsford CC, Nybakken L, Kotilainen TK, Robson TM. The influence of spectral composition on spring and autumn phenology in trees. TREE PHYSIOLOGY 2019; 39:925-950. [PMID: 30901060 DOI: 10.1093/treephys/tpz026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 01/25/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
Several recent reviews highlight the molecular mechanisms that underpin phenological responses to temperature and photoperiod; however, these have mostly overlooked the influence of solar radiation and its spectral composition on these processes. For instance, solar radiation in the blue and ultraviolet (UV) regions of the spectrum, as well as the red/far-red (R:FR) ratio, can influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally; however, rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to spectral composition. Our objective was to explore the natural variation in spectral composition using radiative transfer models and to reveal any species-specific or ecotype-specific responses relating to latitudinal origin. These responses are likely to be most pronounced at high latitudes where spectral composition varies most throughout the year. For instance, trees from high latitudes tend to be more sensitive to changes in R:FR than those from low latitudes. The effects of blue light and UV radiation on phenology have not been studied as much as those of R:FR, but the limited results available suggest both could be candidate cues affecting autumn leaf colouration and senescence. Failure of more-southern species and ecotypes to adapt and use spectral cues during northwards range shifts could result in mistimed phenology, potentially resulting in frost damage, reduced fitness and limited range expansion. Future areas for research should look to establish how consistently different functional types of tree respond to spectral cues and identify photoreceptor-mediated mechanisms that allow plants to combine information from multiple light cues to coordinate the timing of phenological events. It should then be feasible to consider the synchronous or sequential action of light cues within a hierarchy of environmental factors regulating phenology.
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Affiliation(s)
- Craig C Brelsford
- Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Line Nybakken
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Titta K Kotilainen
- Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Natural Resources Institute Finland, Turku, Finland
| | - T Matthew Robson
- Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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25
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Rees H, Duncan S, Gould P, Wells R, Greenwood M, Brabbs T, Hall A. A high-throughput delayed fluorescence method reveals underlying differences in the control of circadian rhythms in Triticum aestivum and Brassica napus. PLANT METHODS 2019; 15:51. [PMID: 31139241 PMCID: PMC6530173 DOI: 10.1186/s13007-019-0436-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 05/10/2019] [Indexed: 05/25/2023]
Abstract
BACKGROUND A robust circadian clock has been implicated in plant resilience, resource-use efficiency, competitive growth and yield. A huge number of physiological processes are under circadian control in plants including: responses to biotic and abiotic stresses; flowering time; plant metabolism; and mineral uptake. Understanding how the clock functions in crops such as Triticum aestivum (bread wheat) and Brassica napus (oilseed rape) therefore has great agricultural potential. Delayed fluorescence (DF) imaging has been shown to be applicable to a wide range of plant species and requires no genetic transformation. Although DF has been used to measure period length of both mutants and wild ecotypes of Arabidopsis, this assay has never been systematically optimised for crop plants. The physical size of both B. napus and T. aestivum led us to develop a representative sampling strategy which enables high-throughput imaging of these crops. RESULTS In this study, we describe the plant-specific optimisation of DF imaging to obtain reliable circadian phenotypes with the robustness and reproducibility to detect diverging periods between cultivars of the same species. We find that the age of plant material, light regime and temperature conditions all significantly effect DF rhythms and describe the optimal conditions for measuring robust rhythms in each species. We also show that sections of leaf can be used to obtain period estimates with improved throughput for larger sample size experiments. CONCLUSIONS We present an optimized protocol for high-throughput phenotyping of circadian period specific to two economically valuable crop plants. Application of this method revealed significant differences between the periods of several widely grown elite cultivars. This method also identified intriguing differential responses of circadian rhythms in T. aestivum compared to B. napus; specifically the dramatic change to rhythm robustness when plants were imaged under constant light versus constant darkness. This points towards diverging networks underlying circadian control in these two species.
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Affiliation(s)
- Hannah Rees
- Earlham Institute, Norwich Research Park, Norwich, NR4 7UG UK
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB UK
| | - Susan Duncan
- Earlham Institute, Norwich Research Park, Norwich, NR4 7UG UK
| | - Peter Gould
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB UK
| | - Rachel Wells
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH UK
| | - Mark Greenwood
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR UK
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW UK
| | - Thomas Brabbs
- Earlham Institute, Norwich Research Park, Norwich, NR4 7UG UK
| | - Anthony Hall
- Earlham Institute, Norwich Research Park, Norwich, NR4 7UG UK
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Brelsford CC, Morales LO, Nezval J, Kotilainen TK, Hartikainen SM, Aphalo PJ, Robson TM. Do UV-A radiation and blue light during growth prime leaves to cope with acute high light in photoreceptor mutants of Arabidopsis thaliana? PHYSIOLOGIA PLANTARUM 2019; 165:537-554. [PMID: 29704249 DOI: 10.1111/ppl.12749] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/14/2018] [Accepted: 04/25/2018] [Indexed: 05/22/2023]
Abstract
We studied how plants acclimated to growing conditions that included combinations of blue light (BL) and ultraviolet (UV)-A radiation, and whether their growing environment affected their photosynthetic capacity during and after a brief period of acute high light (as might happen during an under-canopy sunfleck). Arabidopsis thaliana Landsberg erecta wild-type were compared with mutants lacking functional blue light and UV photoreceptors: phototropin 1, cryptochromes (CRY1 and CRY2) and UV RESISTANT LOCUS 8 (uvr8). This was achieved using light-emitting-diode (LED) lamps in a controlled environment to create treatments with or without BL, in a split-plot design with or without UV-A radiation. We compared the accumulation of phenolic compounds under growth conditions and after exposure to 30 min of high light at the end of the experiment (46 days), and likewise measured the operational efficiency of photosystem II (ϕPSII, a proxy for photosynthetic performance) and dark-adapted maximum quantum yield (Fv /Fm to assess PSII damage). Our results indicate that cryptochromes are the main photoreceptors regulating phenolic compound accumulation in response to BL and UV-A radiation, and a lack of functional cryptochromes impairs photosynthetic performance under high light. Our findings also reveal a role for UVR8 in accumulating flavonoids in response to a low UV-A dose. Interestingly, phototropin 1 partially mediated constitutive accumulation of phenolic compounds in the absence of BL. Low-irradiance BL and UV-A did not improve ϕPSII and Fv /Fm upon our acute high-light treatment; however, CRYs played an important role in ameliorating high-light stress.
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Affiliation(s)
- Craig C Brelsford
- Organismal and Evolutionary Biology Research Programme, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Luis O Morales
- Organismal and Evolutionary Biology Research Programme, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Jakub Nezval
- Faculty of Science, University of Ostrava, 701 03 Ostrava, Czech Republic
| | - Titta K Kotilainen
- Organismal and Evolutionary Biology Research Programme, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Saara M Hartikainen
- Organismal and Evolutionary Biology Research Programme, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Pedro J Aphalo
- Organismal and Evolutionary Biology Research Programme, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - T Matthew Robson
- Organismal and Evolutionary Biology Research Programme, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
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27
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Cano-Ramirez DL, Dodd AN. New connections between circadian rhythms, photosynthesis, and environmental adaptation. PLANT, CELL & ENVIRONMENT 2018; 41:2515-2517. [PMID: 29785736 DOI: 10.1111/pce.13346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 05/16/2018] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
This article comments on: Circadian rhythms are associated with variation in photosystem II function and photoprotective mechanisms.
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Affiliation(s)
- Dora L Cano-Ramirez
- School of Biological Sciences, Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Antony N Dodd
- School of Biological Sciences, Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
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28
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Yarkhunova Y, Guadagno CR, Rubin MJ, Davis SJ, Ewers BE, Weinig C. Circadian rhythms are associated with variation in photosystem II function and photoprotective mechanisms. PLANT, CELL & ENVIRONMENT 2018; 41:2518-2529. [PMID: 29664141 DOI: 10.1111/pce.13216] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 04/02/2018] [Accepted: 04/03/2018] [Indexed: 06/08/2023]
Abstract
The circadian clock regulates many aspects of leaf gas supply and biochemical demand for CO2 , and is hypothesized to improve plant performance. Yet the extent to which the clock may regulate the efficiency of photosystem II (PSII) and photoprotective mechanisms such as heat dissipation is less explored. Based on measurements of chlorophyll a fluorescence, we estimated the maximum efficiency of PSII in light (Fv'/Fm') and heat dissipation by nonphotochemical quenching (NPQ). We further dissected total NPQ into its main components, qE (pH-dependent quenching), qT (state-transition quenching), and qI (quenching related to photoinhibition), in clock mutant genotypes of Arabidopsis thaliana, the cognate wild-type genotypes, and a panel of recombinant inbred lines expressing quantitative variation in clock period. Compared with mutants with altered clock function, we observed that wild-type genotypes with clock period lengths of approximately 24 hr had both higher levels of Fv'/Fm', indicative of improved PSII function, and reduced NPQ, suggestive of lower stress on PSII light harvesting complexes. In the recombinant inbred lines, genetic variances were significant for Fv'/Fm' and all 3 components of NPQ, with qE explaining the greatest proportion of NPQ. Bivariate tests of association and structural equation models of hierarchical trait relationships showed that quantitative clock variation was empirically associated with Fv'/Fm' and NPQ, with qE mediating the relationship with gas exchange. The results demonstrate significant segregating variation for all photoprotective components, and suggest the adaptive significance of the clock may partly derive from its regulation of the light reactions of photosynthesis and of photoprotective mechanisms.
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Affiliation(s)
- Yulia Yarkhunova
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
| | - Carmela R Guadagno
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
| | - Matthew J Rubin
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
| | - Seth J Davis
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Brent E Ewers
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
| | - Cynthia Weinig
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
- Department of Molecular Biology, University of Wyoming, Laramie, WY, 82071, USA
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29
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Litthauer S, Jones MA. SAL1-PAP retrograde signalling extends circadian period by reproducing the loss of exoribonuclease (XRN) activity. PLANT SIGNALING & BEHAVIOR 2018; 13:e1500066. [PMID: 30081763 PMCID: PMC6149516 DOI: 10.1080/15592324.2018.1500066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 07/04/2018] [Indexed: 05/31/2023]
Abstract
Plants have developed an internal timing mechanism, the circadian system, that serves to synchronise physiological and metabolic functions with daily cues such as dawn and dusk, and provides plants with an advantage in adapting to changing and challenging conditions. We have recently shown that the SAL1-PAP-XRN retrograde signalling pathway, which is proposed to regulate plant responses under stress conditions, also acts within the circadian system. Here we provide further evidence of circadian regulation by SAL1-PAP-XRN signalling, thereby affirming a link between molecular timekeeping and abiotic stress response mechanisms.
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30
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Gould PD, Domijan M, Greenwood M, Tokuda IT, Rees H, Kozma-Bognar L, Hall AJ, Locke JC. Coordination of robust single cell rhythms in the Arabidopsis circadian clock via spatial waves of gene expression. eLife 2018; 7:31700. [PMID: 29697372 PMCID: PMC5988422 DOI: 10.7554/elife.31700] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 04/25/2018] [Indexed: 11/13/2022] Open
Abstract
The Arabidopsis circadian clock orchestrates gene regulation across the day/night cycle. Although a multiple feedback loop circuit has been shown to generate the 24-hr rhythm, it remains unclear how robust the clock is in individual cells, or how clock timing is coordinated across the plant. Here we examine clock activity at the single cell level across Arabidopsis seedlings over several days under constant environmental conditions. Our data reveal robust single cell oscillations, albeit desynchronised. In particular, we observe two waves of clock activity; one going down, and one up the root. We also find evidence of cell-to-cell coupling of the clock, especially in the root tip. A simple model shows that cell-to-cell coupling and our measured period differences between cells can generate the observed waves. Our results reveal the spatial structure of the plant clock and suggest that unlike the centralised mammalian clock, the Arabidopsis clock has multiple coordination points.
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Affiliation(s)
- Peter D Gould
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Mirela Domijan
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Mathematical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Mark Greenwood
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Isao T Tokuda
- Department of Mechanical Engineering, Ritsumeikan University, Kusatsu, Japan
| | - Hannah Rees
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Laszlo Kozma-Bognar
- Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Genetics, University of Szeged, Szeged, Hungary
| | - Anthony Jw Hall
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | - James Cw Locke
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.,Microsoft Research, Cambridge, United Kingdom
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Guadagno CR, Ewers BE, Weinig C. Circadian Rhythms and Redox State in Plants: Till Stress Do Us Part. FRONTIERS IN PLANT SCIENCE 2018; 9:247. [PMID: 29556244 PMCID: PMC5844964 DOI: 10.3389/fpls.2018.00247] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/12/2018] [Indexed: 05/22/2023]
Abstract
A growing body of evidence demonstrates a significant relationship between cellular redox state and circadian rhythms. Each day these two vital components of plant biology influence one another, dictating the pace for metabolism and physiology. Diverse environmental stressors can disrupt this condition and, although plant scientists have made significant progress in re-constructing functional networks of plant stress responses, stress impacts on the clock-redox crosstalk is poorly understood. Inter-connected phenomena such as redox state and metabolism, internal and external environments, cellular homeostasis and rhythms can impede predictive understanding of coordinated regulation of plant stress response. The integration of circadian clock effects into predictive network models is likely to increase final yield and better predict plant responses to stress. To achieve such integrated understanding, it is necessary to consider the internal clock not only as a gatekeeper of environmental responses but also as a target of stress syndromes. Using chlorophyll fluorescence as a reliable and high-throughput probe of stress coupled to functional genomics and metabolomics will provide insights on the crosstalk across a wide range of stress severity and duration, including potential insights into oxidative stress response and signaling. We suggest the efficiency of photosystem II in light conditions (Fv'/Fm') to be the most dynamic of the fluorescence variables and therefore the most reliable parameter to follow the stress response from early sensing to mortality.
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Affiliation(s)
| | - Brent E. Ewers
- Department of Botany, University of Wyoming, Laramie, WY, United States
- Program in Ecology, University of Wyoming, Laramie, WY, United States
| | - Cynthia Weinig
- Department of Botany, University of Wyoming, Laramie, WY, United States
- Program in Ecology, University of Wyoming, Laramie, WY, United States
- Department of Molecular and Cellular Life Sciences, University of Wyoming, Laramie, WY, United States
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32
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Night Light-Adaptation Strategies for Photosynthetic Apparatus in Yellow-Poplar (Liriodendron tulipifera L.) Exposed to Artificial Night Lighting. FORESTS 2018. [DOI: 10.3390/f9020074] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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33
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Joo Y, Fragoso V, Yon F, Baldwin IT, Kim SG. Circadian clock component, LHY, tells a plant when to respond photosynthetically to light in nature. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:572-587. [PMID: 28429400 DOI: 10.1111/jipb.12547] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/18/2017] [Indexed: 05/14/2023]
Abstract
The circadian clock is known to increase plant growth and fitness, and is thought to prepare plants for photosynthesis at dawn and dusk; whether this happens in nature was unknown. We transformed the native tobacco, Nicotiana attenuata to silence two core clock components, NaLHY (irLHY) and NaTOC1 (irTOC1). We characterized growth and light- and dark-adapted photosynthetic rates (Ac ) throughout a 24 h day in empty vector-transformed (EV), irLHY, and irTOC1 plants in the field, and in NaPhyA- and NaPhyB1-silenced plants in the glasshouse. The growth rates of irLHY plants were lower than those of EV plants in the field. While irLHY plants reduced Ac earlier at dusk, no differences between irLHY and EV plants were observed at dawn in the field. irLHY, but not EV plants, responded to light in the night by rapidly increasing Ac . Under controlled conditions, EV plants rapidly increased Ac in the day compared to dark-adapted plants at night; irLHY plants lost these time-dependent responses. The role of NaLHY in gating photosynthesis is independent of the light-dependent reactions and red light perceived by NaPhyA, but not NaPhyB1. In summary, the circadian clock allows plants not to respond photosynthetically to light at night by anticipating and gating red light-mediated in native tobacco.
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Affiliation(s)
- Youngsung Joo
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Variluska Fragoso
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Felipe Yon
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Ian T Baldwin
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Sang-Gyu Kim
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
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34
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Jones MA. Interplay of Circadian Rhythms and Light in the Regulation of Photosynthesis-Derived Metabolism. PROGRESS IN BOTANY VOL. 79 2017:147-171. [PMID: 0 DOI: 10.1007/124_2017_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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35
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Trivellini A, Cocetta G, Hunter DA, Vernieri P, Ferrante A. Spatial and temporal transcriptome changes occurring during flower opening and senescence of the ephemeral hibiscus flower, Hibiscus rosa-sinensis. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:5919-5931. [PMID: 27591432 PMCID: PMC5091337 DOI: 10.1093/jxb/erw295] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Flowers are complex systems whose vegetative and sexual structures initiate and die in a synchronous manner. The rapidity of this process varies widely in flowers, with some lasting for months while others such as Hibiscus rosa-sinensis survive for only a day. The genetic regulation underlying these differences is unclear. To identify key genes and pathways that coordinate floral organ senescence of ephemeral flowers, we identified transcripts in H. rosa-sinensis floral organs by 454 sequencing. During development, 2053 transcripts increased and 2135 decreased significantly in abundance. The senescence of the flower was associated with increased abundance of many hydrolytic genes, including aspartic and cysteine proteases, vacuolar processing enzymes, and nucleases. Pathway analysis suggested that transcripts altering significantly in abundance were enriched in functions related to cell wall-, aquaporin-, light/circadian clock-, autophagy-, and calcium-related genes. Finding enrichment in light/circadian clock-related genes fits well with the observation that hibiscus floral development is highly synchronized with light and the hypothesis that ageing/senescence of the flower is orchestrated by a molecular clock. Further study of these genes will provide novel insight into how the molecular clock is able to regulate the timing of programmed cell death in tissues.
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Affiliation(s)
- Alice Trivellini
- Institute of Life Science, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Giacomo Cocetta
- Department of Agricultural and Environmental Sciences, Università degli Studi Milano, Milan, Italy
| | - Donald A Hunter
- The New Zealand Institute for Plant & Food Research Limited, Palmerston North, New Zealand
| | - Paolo Vernieri
- Department of Agriculture, Food and Environment, Università degli Studi di Pisa, Pisa, Italy
| | - Antonio Ferrante
- Department of Agricultural and Environmental Sciences, Università degli Studi Milano, Milan, Italy
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36
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Leister D, Kleine T. Definition of a core module for the nuclear retrograde response to altered organellar gene expression identifies GLK overexpressors as gun mutants. PHYSIOLOGIA PLANTARUM 2016; 157:297-309. [PMID: 26876646 DOI: 10.1111/ppl.12431] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 12/28/2015] [Accepted: 01/04/2016] [Indexed: 05/03/2023]
Abstract
Retrograde signaling can be triggered by changes in organellar gene expression (OGE) induced by inhibitors such as lincomycin (LIN) or mutations that perturb OGE. Thus, an insufficiency of the organelle-targeted prolyl-tRNA synthetase PRORS1 in Arabidopsis thaliana activates retrograde signaling and reduces the expression of nuclear genes for photosynthetic proteins. Recently, we showed that mTERF6, a member of the so-called mitochondrial transcription termination factor (mTERF) family, is involved in the formation of chloroplast (cp) isoleucine-tRNA. To obtain further insights into its functions, co-expression analysis of MTERF6, PRORS1 and two other genes for organellar aminoacyl-tRNA synthetases was conducted. The results suggest a prominent role of mTERF6 in aminoacylation activity, light signaling and seed storage. Analysis of changes in whole-genome transcriptomes in the mterf6-1 mutant showed that levels of nuclear transcripts for cp OGE proteins were particularly affected. Comparison of the mterf6-1 transcriptome with that of prors1-2 showed that reduced aminoacylation of proline (prors1-2) and isoleucine (mterf6-1) tRNAs alters retrograde signaling in similar ways. Database analyses indicate that comparable gene expression changes are provoked by treatment with LIN, norflurazon or high light. A core OGE response module was defined by identifying genes that were differentially expressed under at least four of six conditions relevant to OGE signaling. Based on this module, overexpressors of the Golden2-like transcription factors GLK1 and GLK2 were identified as genomes uncoupled mutants.
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Affiliation(s)
- Dario Leister
- Lehrstuhl für Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität, Planegg-Martinsried, Munich, Germany
| | - Tatjana Kleine
- Lehrstuhl für Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität, Planegg-Martinsried, Munich, Germany
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37
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Litthauer S, Battle MW, Jones MA. Phototropins do not alter accumulation of evening-phased circadian transcripts under blue light. PLANT SIGNALING & BEHAVIOR 2016; 11:e1126029. [PMID: 26653107 PMCID: PMC4883876 DOI: 10.1080/15592324.2015.1126029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 11/23/2015] [Accepted: 11/23/2015] [Indexed: 05/18/2023]
Abstract
The circadian system induces rhythmic variation in a suite of biochemical and physiological processes that serve to optimise plant growth in diel cycles. To be of greatest utility, these rhythmic behaviors are coordinated with regular environmental changes such as the rising and setting of the sun. Photoreceptors, along with metabolites produced during photosynthesis, act to synchronise the internal timing mechanism with lighting cues. We have recently shown that phototropins help maintain robust rhythms of photosynthetic operating efficiency (ϕPSII or Fq'/Fm') under blue light, although rhythmic accumulation of morning-phased circadian transcripts in the nucleus was unaffected. Here we report that evening-phased nuclear clock transcripts were also unaffected. We also observe that rhythms of nuclear clock transcript accumulation are maintained in phototropin mutant plants under a fluctuating lighting regime that induced a loss of Fq'/Fm' rhythms.
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Affiliation(s)
- Suzanne Litthauer
- a School of Biological Sciences, University of Essex , Wivenhoe Park, United Kingdom
| | - Martin W Battle
- a School of Biological Sciences, University of Essex , Wivenhoe Park, United Kingdom
| | - Matthew A Jones
- a School of Biological Sciences, University of Essex , Wivenhoe Park, United Kingdom
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