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Llorens L, Cortés L, Boira H. Deciphering the ecology of the threatened microendemic species Euphorbia margalidiana. FRONTIERS IN PLANT SCIENCE 2023; 14:1155896. [PMID: 37434601 PMCID: PMC10332272 DOI: 10.3389/fpls.2023.1155896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/13/2023] [Indexed: 07/13/2023]
Abstract
Small islands play a critical role in the study of plant ecology and evolution. Here, we reveal the ecology of Euphorbia margalidiana, an endemic plant that thrives in a micro-island environment in the Western Mediterranean region. Through a detailed characterization of the habitat, including plant communities, microclimate, soil properties, and germination assays, we examine the effects of biotic and abiotic factors on the distribution of this endangered species. We also analyze its pollination biology, evaluate the success of vegetative propagation, and discuss its potential use in conservation strategies. Our results show that E. margalidiana is a characteristic species of the shrub ornitocoprophilous insular vegetation of the Western Mediterranean. The seeds have a very low dispersion capacity outside the islet and that seed-derived plants have higher survival rates under drought conditions than those vegetatively propagated. The main volatile compound emitted from the pseudanthia is phenol which attracts the plants' main and almost exclusive pollinators in the islet, flies. Our results confirm the relictual status of E. margalidiana and highlight the importance of key adaptive traits that enable the survival of this species in the harsh micro-island environment of Ses Margalides.
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Affiliation(s)
- Leonardo Llorens
- Interdisciplinary Ecology Group, Department of Biology, University of the Balearic Islands (UIB), Palma de Mallorca, Balearic Islands, Spain
| | - Lucas Cortés
- Independent Researcher, Palma de Mallorca, Spain
| | - Herminio Boira
- Institute of Mediterranean Agroforestry (IAM), Polytechnic University of Valencia (UPV), Valencia, Spain
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Label-Free Quantitative Proteomics Reveal the Involvement of PRT6 in Arabidopsis thaliana Seed Responsiveness to Ethylene. Int J Mol Sci 2022; 23:ijms23169352. [PMID: 36012613 PMCID: PMC9409418 DOI: 10.3390/ijms23169352] [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] [Received: 07/15/2022] [Revised: 08/11/2022] [Accepted: 08/16/2022] [Indexed: 11/17/2022] Open
Abstract
In Arabidopsis thaliana, the breaking of seed dormancy in wild type (Col-0) by ethylene at 100 μL L-1 required at least 30 h application. A mutant of the proteolytic N-degron pathway, lacking the E3 ligase PROTEOLYSIS 6 (PRT6), was investigated for its role in ethylene-triggered changes in proteomes during seed germination. Label-free quantitative proteomics was carried out on dormant wild type Col-0 and prt6 seeds treated with (+) or without (-) ethylene. After 16 h, 1737 proteins were identified, but none was significantly different in protein levels in response to ethylene. After longer ethylene treatment (30 h), 2552 proteins were identified, and 619 Differentially Expressed Proteins (DEPs) had significant differences in protein abundances between ethylene treatments and genotypes. In Col, 587 DEPs were enriched for those involved in signal perception and transduction, reserve mobilization and new material generation, which potentially contributed to seed germination. DEPs up-regulated by ethylene in Col included S-adenosylmethionine synthase 1, methionine adenosyltransferase 3 and ACC oxidase involved in ethylene synthesis and of Pyrabactin Resistance1 acting as an ABA receptor, while DEPs down-regulated by ethylene in Col included aldehyde oxidase 4 involved in ABA synthesis. In contrast, in prt6 seeds, ethylene did not result in strong proteomic changes with only 30 DEPs. Taken together, the present work demonstrates that the proteolytic N-degron pathway is essential for ethylene-mediated reprogramming of seed proteomes during germination.
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Jethva J, Schmidt RR, Sauter M, Selinski J. Try or Die: Dynamics of Plant Respiration and How to Survive Low Oxygen Conditions. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11020205. [PMID: 35050092 PMCID: PMC8780655 DOI: 10.3390/plants11020205] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/07/2022] [Accepted: 01/11/2022] [Indexed: 05/09/2023]
Abstract
Fluctuations in oxygen (O2) availability occur as a result of flooding, which is periodically encountered by terrestrial plants. Plant respiration and mitochondrial energy generation rely on O2 availability. Therefore, decreased O2 concentrations severely affect mitochondrial function. Low O2 concentrations (hypoxia) induce cellular stress due to decreased ATP production, depletion of energy reserves and accumulation of metabolic intermediates. In addition, the transition from low to high O2 in combination with light changes-as experienced during re-oxygenation-leads to the excess formation of reactive oxygen species (ROS). In this review, we will update our current knowledge about the mechanisms enabling plants to adapt to low-O2 environments, and how to survive re-oxygenation. New insights into the role of mitochondrial retrograde signaling, chromatin modification, as well as moonlighting proteins and mitochondrial alternative electron transport pathways (and their contribution to low O2 tolerance and survival of re-oxygenation), are presented.
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Affiliation(s)
- Jay Jethva
- Department of Plant Developmental Biology and Plant Physiology, Faculty of Mathematics and Natural Sciences, Botanical Institute, Christian-Albrechts University, D-24118 Kiel, Germany; (J.J.); (M.S.)
| | - Romy R. Schmidt
- Department of Plant Biotechnology, Faculty of Biology, University of Bielefeld, D-33615 Bielefeld, Germany;
| | - Margret Sauter
- Department of Plant Developmental Biology and Plant Physiology, Faculty of Mathematics and Natural Sciences, Botanical Institute, Christian-Albrechts University, D-24118 Kiel, Germany; (J.J.); (M.S.)
| | - Jennifer Selinski
- Department of Plant Cell Biology, Botanical Institute, Faculty of Mathematics and Natural Sciences, Christian-Albrechts University, D-24118 Kiel, Germany
- Correspondence: ; Tel.: +49-(0)431-880-4245
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Kong W, Tan S, Zhao Q, Lin DL, Xu ZH, Friml J, Xue HW. mRNA surveillance complex PELOTA-HBS1 regulates phosphoinositide-dependent protein kinase1 and plant growth. PLANT PHYSIOLOGY 2021; 186:2003-2020. [PMID: 33930167 PMCID: PMC8331137 DOI: 10.1093/plphys/kiab199] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/15/2021] [Indexed: 05/06/2023]
Abstract
The quality control system for messenger RNA (mRNA) is fundamental for cellular activities in eukaryotes. To elucidate the molecular mechanism of 3'-phosphoinositide-dependent protein kinase1 (PDK1), a master regulator that is essential throughout eukaryotic growth and development, we employed a forward genetic approach to screen for suppressors of the loss-of-function T-DNA insertion double mutant pdk1.1 pdk1.2 in Arabidopsis thaliana. Notably, the severe growth attenuation of pdk1.1 pdk1.2 was rescued by sop21 (suppressor of pdk1.1 pdk1.2), which harbors a loss-of-function mutation in PELOTA1 (PEL1). PEL1 is a homolog of mammalian PELOTA and yeast (Saccharomyces cerevisiae) DOM34p, which each form a heterodimeric complex with the GTPase HBS1 (HSP70 SUBFAMILY B SUPPRESSOR1, also called SUPERKILLER PROTEIN7, SKI7), a protein that is responsible for ribosomal rescue and thereby assures the quality and fidelity of mRNA molecules during translation. Genetic analysis further revealed that a dysfunctional PEL1-HBS1 complex failed to degrade the T-DNA-disrupted PDK1 transcripts, which were truncated but functional, and thus rescued the growth and developmental defects of pdk1.1 pdk1.2. Our studies demonstrated the functionality of a homologous PELOTA-HBS1 complex and identified its essential regulatory role in plants, providing insights into the mechanism of mRNA quality control.
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Affiliation(s)
- Wei Kong
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Shutang Tan
- School of Life Sciences, Division of Life Sciences and Medicine, and Division of Molecular & Cell Biophysics, Hefei National Science Centre for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230027, China
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, Klosterneuburg, 3400, Austria
| | - Qing Zhao
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - De-Li Lin
- Joint Centre for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhi-Hong Xu
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Jiří Friml
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, Klosterneuburg, 3400, Austria
| | - Hong-Wei Xue
- Joint Centre for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
- Author for communication:
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Xu D, Dhiman R, Garibay A, Mock HP, Leister D, Kleine T. Cellulose defects in the Arabidopsis secondary cell wall promote early chloroplast development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:156-170. [PMID: 31498930 DOI: 10.1111/tpj.14527] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/12/2019] [Accepted: 08/28/2019] [Indexed: 06/10/2023]
Abstract
Lincomycin (LIN)-mediated inhibition of protein synthesis in chloroplasts prevents the greening of seedlings, represses the activity of photosynthesis-related genes in the nucleus, including LHCB1.2, and induces the phenylpropanoid pathway, resulting in the production of anthocyanins. In genomes uncoupled (gun) mutants, LHCB1.2 expression is maintained in the presence of LIN or other inhibitors of early chloroplast development. In a screen using concentrations of LIN lower than those employed to isolate gun mutants, we have identified happy on lincomycin (holi) mutants. Several holi mutants show an increased tolerance to LIN, exhibiting de-repressed LHCB1.2 expression and chlorophyll synthesis in seedlings. The mutations responsible were identified by whole-genome single-nucleotide polymorphism (SNP) mapping, and most were found to affect the phenylpropanoid pathway; however, LHCB1.2 expression does not appear to be directly regulated by phenylpropanoids, as indicated by the metabolic profiling of mutants. The most potent holi mutant is defective in a subunit of cellulose synthase encoded by IRREGULAR XYLEM 3, and comparative analysis of this and other cell-wall mutants establishes a link between secondary cell-wall integrity and early chloroplast development, possibly involving altered ABA metabolism or sensing.
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Affiliation(s)
- Duorong Xu
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Ravi Dhiman
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Adriana Garibay
- Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK-Gatersleben), Corrensstraße 3, 06466, Stadt Seeland, OT Gatersleben, Germany
| | - Hans-Peter Mock
- Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK-Gatersleben), Corrensstraße 3, 06466, Stadt Seeland, OT Gatersleben, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Tatjana Kleine
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
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Bäumler J, Riber W, Klecker M, Müller L, Dissmeyer N, Weig AR, Mustroph A. AtERF#111/ABR1 is a transcriptional activator involved in the wounding response. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:969-990. [PMID: 31385625 DOI: 10.1111/tpj.14490] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 07/24/2019] [Accepted: 07/29/2019] [Indexed: 06/10/2023]
Abstract
AtERF#111/ABR1 belongs to the group X of the ERF/AP2 transcription factor family (GXERFs) and is shoot specifically induced under submergence and hypoxia. It was described to be an ABA-response repressor, but our data reveal a completely different function. Surprisingly, AtERF#111 expression is strongly responsive to wounding stress. Expression profiling of ERF#111-overexpressing (OE) plants, which show morphological phenotypes like increased root hair length and number, strengthens the hypothesis of AtERF#111 being involved in the wounding response, thereby acting as a transcriptional activator of gene expression. Consistent with a potential function outside of oxygen signalling, we could not assign AtERF#111 as a target of the PRT6 N-degron pathway, even though it starts with a highly conserved N-terminal Met-Cys (MC) motif. However, the protein is unstable as it is degraded in an ubiquitin-dependent manner. Finally, direct target genes of AtERF#111 were identified by microarray analyses and subsequently confirmed by protoplast transactivation assays. The special roles of diverse members of the plant-specific GXERFs in coordinating stress signalling and wound repair mechanisms have been recently hypothesized, and our data suggest that AtERF#111 is indeed involved in these processes.
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Affiliation(s)
- Judith Bäumler
- Plant Physiology, University Bayreuth, Universitaetsstr. 30, 95440, Bayreuth, Germany
| | - Willi Riber
- Plant Physiology, University Bayreuth, Universitaetsstr. 30, 95440, Bayreuth, Germany
| | - Maria Klecker
- Plant Physiology, University Bayreuth, Universitaetsstr. 30, 95440, Bayreuth, Germany
- Independent Junior Research Group on Protein Recognition and Degradation, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
- Science Campus Halle - Plant-Based Bioeconomy, Betty-Heimann-Str. 3, 06120, Halle (Saale), Germany
| | - Leon Müller
- Plant Physiology, University Bayreuth, Universitaetsstr. 30, 95440, Bayreuth, Germany
| | - Nico Dissmeyer
- Independent Junior Research Group on Protein Recognition and Degradation, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
- Science Campus Halle - Plant-Based Bioeconomy, Betty-Heimann-Str. 3, 06120, Halle (Saale), Germany
| | - Alfons R Weig
- Genomics & Bioinformatics, University Bayreuth, Universitaetsstr. 30, 95440, Bayreuth, Germany
| | - Angelika Mustroph
- Plant Physiology, University Bayreuth, Universitaetsstr. 30, 95440, Bayreuth, Germany
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Zhang H, Gannon L, Jones PD, Rundle CA, Hassall KL, Gibbs DJ, Holdsworth MJ, Theodoulou FL. Genetic interactions between ABA signalling and the Arg/N-end rule pathway during Arabidopsis seedling establishment. Sci Rep 2018; 8:15192. [PMID: 30315202 PMCID: PMC6185960 DOI: 10.1038/s41598-018-33630-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/01/2018] [Indexed: 11/25/2022] Open
Abstract
The Arg/N-end rule pathway of ubiquitin-mediated proteolysis has multiple functions throughout plant development, notably in the transition from dormant seed to photoautotrophic seedling. PROTEOLYSIS6 (PRT6), an N-recognin E3 ligase of the Arg/N-end rule regulates the degradation of transcription factor substrates belonging to Group VII of the Ethylene Response Factor superfamily (ERFVIIs). It is not known whether ERFVIIs are associated with all known functions of the Arg/N-end rule, and the downstream pathways influenced by ERFVIIs are not fully defined. Here, we examined the relationship between PRT6 function, ERFVIIs and ABA signalling in Arabidopsis seedling establishment. Physiological analysis of seedlings revealed that N-end rule-regulated stabilisation of three of the five ERFVIIs, RAP2.12, RAP2.2 and RAP2.3, controls sugar sensitivity of seedling establishment and oil body breakdown following germination. ABA signalling components ABA INSENSITIVE (ABI)4 as well as ABI3 and ABI5 were found to enhance ABA sensitivity of germination and sugar sensitivity of establishment in a background containing stabilised ERFVIIs. However, N-end rule regulation of oil bodies was not dependent on canonical ABA signalling. We propose that the N-end rule serves to control multiple aspects of the seed to seedling transition by regulation of ERFVII activity, involving both ABA-dependent and independent signalling pathways.
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Affiliation(s)
- Hongtao Zhang
- Plant Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Lucy Gannon
- Plant Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Peter D Jones
- School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK.,Department of Cardiovascular Sciences, University of Leicester, Leicester, LE3 7QP, UK
| | - Chelsea A Rundle
- Plant Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Kirsty L Hassall
- Computational and Analytical Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
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Over-expression of SINAL7 increases biomass and drought tolerance, and also delays senescence in Arabidopsis. J Biotechnol 2018; 283:11-21. [PMID: 30003973 DOI: 10.1016/j.jbiotec.2018.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 06/10/2018] [Accepted: 07/08/2018] [Indexed: 11/22/2022]
Abstract
The seven in absentia like 7 gene (At5g37890, SINAL7) from Arabidopsis thaliana encodes a RING finger protein belonging to the SINA superfamily that possesses E3 ubiquitin-ligase activity. SINAL7 has the ability to self-ubiquitinate and to mono-ubiquitinate glyceraldehyde-3-P dehydrogenase 1 (GAPC1), suggesting a role for both proteins in a hypothetical signaling pathway in Arabidopsis. In this study, the in vivo effects of SINAL7 on plant physiology were examined by over-expressing SINAL7 in transgenic Arabidopsis plants. Phenotypic and gene expression analyses suggest the involvement of SINAL7 in the regulation of several vegetative parameters, essentially those that affect the aerial parts of the plants. Over-expression of SINAL7 resulted in an increase in the concentrations of hexoses and sucrose, with a concommitant increase in plant biomass, particularly in the number of rosette leaves and stem thickness. Interestingly, using the CAB1 (chlorophyll ab binding protein 1) gene as a marker revealed a delay in the onset of senescence. Transgenic plants also displayed a remarkable level of drought resistance, indicating the complexity of the response to SINAL7 over-expression.
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Salem MA, Li Y, Bajdzienko K, Fisahn J, Watanabe M, Hoefgen R, Schöttler MA, Giavalisco P. RAPTOR Controls Developmental Growth Transitions by Altering the Hormonal and Metabolic Balance. PLANT PHYSIOLOGY 2018; 177:565-593. [PMID: 29686055 PMCID: PMC6001337 DOI: 10.1104/pp.17.01711] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/06/2018] [Indexed: 05/18/2023]
Abstract
Vegetative growth requires the systemic coordination of numerous cellular processes, which are controlled by regulatory proteins that monitor extracellular and intracellular cues and translate them into growth decisions. In eukaryotes, one of the central factors regulating growth is the serine/threonine protein kinase Target of Rapamycin (TOR), which forms complexes with regulatory proteins. To understand the function of one such regulatory protein, Regulatory-Associated Protein of TOR 1B (RAPTOR1B), in plants, we analyzed the effect of raptor1b mutations on growth and physiology in Arabidopsis (Arabidopsis thaliana) by detailed phenotyping, metabolomic, lipidomic, and proteomic analyses. Mutation of RAPTOR1B resulted in a strong reduction of TOR kinase activity, leading to massive changes in central carbon and nitrogen metabolism, accumulation of excess starch, and induction of autophagy. These shifts led to a significant reduction of plant growth that occurred nonlinearly during developmental stage transitions. This phenotype was accompanied by changes in cell morphology and tissue anatomy. In contrast to previous studies in rice (Oryza sativa), we found that the Arabidopsis raptor1b mutation did not affect chloroplast development or photosynthetic electron transport efficiency; however, it resulted in decreased CO2 assimilation rate and increased stomatal conductance. The raptor1b mutants also had reduced abscisic acid levels. Surprisingly, abscisic acid feeding experiments resulted in partial complementation of the growth phenotypes, indicating the tight interaction between TOR function and hormone synthesis and signaling in plants.
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Affiliation(s)
- Mohamed A. Salem
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Yan Li
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | | | - Joachim Fisahn
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Mutsumi Watanabe
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Rainer Hoefgen
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | | | - Patrick Giavalisco
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
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Zhang H, Gannon L, Hassall KL, Deery MJ, Gibbs DJ, Holdsworth MJ, van der Hoorn RAL, Lilley KS, Theodoulou FL. N-terminomics reveals control of Arabidopsis seed storage proteins and proteases by the Arg/N-end rule pathway. THE NEW PHYTOLOGIST 2018; 218:1106-1126. [PMID: 29168982 PMCID: PMC5947142 DOI: 10.1111/nph.14909] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/23/2017] [Indexed: 05/04/2023]
Abstract
The N-end rule pathway of targeted protein degradation is an important regulator of diverse processes in plants but detailed knowledge regarding its influence on the proteome is lacking. To investigate the impact of the Arg/N-end rule pathway on the proteome of etiolated seedlings, we used terminal amine isotopic labelling of substrates with tandem mass tags (TMT-TAILS) for relative quantification of N-terminal peptides in prt6, an Arabidopsis thaliana N-end rule mutant lacking the E3 ligase PROTEOLYSIS6 (PRT6). TMT-TAILS identified over 4000 unique N-terminal peptides representing c. 2000 protein groups. Forty-five protein groups exhibited significantly increased N-terminal peptide abundance in prt6 seedlings, including cruciferins, major seed storage proteins, which were regulated by Group VII Ethylene Response Factor (ERFVII) transcription factors, known substrates of PRT6. Mobilisation of endosperm α-cruciferin was delayed in prt6 seedlings. N-termini of several proteases were downregulated in prt6, including RD21A. RD21A transcript, protein and activity levels were downregulated in a largely ERFVII-dependent manner. By contrast, cathepsin B3 protein and activity were upregulated by ERFVIIs independent of transcript. We propose that the PRT6 branch of the pathway regulates protease activities in a complex manner and optimises storage reserve mobilisation in the transition from seed to seedling via control of ERFVII action.
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Affiliation(s)
- Hongtao Zhang
- Plant Sciences DepartmentRothamsted ResearchHarpendenAL5 2JQUK
- Cambridge Centre for ProteomicsDepartment of Biochemistry and Cambridge Systems Biology CentreUniversity of CambridgeCambridge, CB2 1QRUK
| | - Lucy Gannon
- Plant Sciences DepartmentRothamsted ResearchHarpendenAL5 2JQUK
| | - Kirsty L. Hassall
- Computational and Analytical Sciences DepartmentRothamsted ResearchHarpendenAL5 2JQUK
| | - Michael J. Deery
- Cambridge Centre for ProteomicsDepartment of Biochemistry and Cambridge Systems Biology CentreUniversity of CambridgeCambridge, CB2 1QRUK
| | - Daniel J. Gibbs
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
| | | | | | - Kathryn S. Lilley
- Cambridge Centre for ProteomicsDepartment of Biochemistry and Cambridge Systems Biology CentreUniversity of CambridgeCambridge, CB2 1QRUK
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Kleine T, Leister D. Retrograde signaling: Organelles go networking. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1313-1325. [PMID: 26997501 DOI: 10.1016/j.bbabio.2016.03.017] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/09/2016] [Accepted: 03/14/2016] [Indexed: 10/25/2022]
Abstract
The term retrograde signaling refers to the fact that chloroplasts and mitochondria utilize specific signaling molecules to convey information on their developmental and physiological states to the nucleus and modulate the expression of nuclear genes accordingly. Signals emanating from plastids have been associated with two main networks: 'Biogenic control' is active during early stages of chloroplast development, while 'operational' control functions in response to environmental fluctuations. Early work focused on the former and its major players, the GUN proteins. However, our view of retrograde signaling has since been extended and revised. Elements of several 'operational' signaling circuits have come to light, including metabolites, signaling cascades in the cytosol and transcription factors. Here, we review recent advances in the identification and characterization of retrograde signaling components. We place particular emphasis on the strategies employed to define signaling components, spanning the entire spectrum of genetic screens, metabolite profiling and bioinformatics. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Tatjana Kleine
- Plant Molecular Biology (Botany), Department Biology I, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Dario Leister
- Plant Molecular Biology (Botany), Department Biology I, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany; Copenhagen Plant Science Centre (CPSC), Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
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12
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Riber W, Müller JT, Visser EJW, Sasidharan R, Voesenek LACJ, Mustroph A. The greening after extended darkness1 is an N-end rule pathway mutant with high tolerance to submergence and starvation. PLANT PHYSIOLOGY 2015; 167:1616-29. [PMID: 25667318 PMCID: PMC4378152 DOI: 10.1104/pp.114.253088] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 02/08/2015] [Indexed: 05/21/2023]
Abstract
Plants respond to reductions in internal oxygen concentrations with adaptive mechanisms (for example, modifications of metabolism to cope with reduced supply of ATP). These responses are, at the transcriptional level, mediated by the group VII Ethylene Response Factor transcription factors, which have stability that is regulated by the N-end rule pathway of protein degradation. N-end rule pathway mutants are characterized by a constitutive expression of hypoxia response genes and abscisic acid hypersensitivity. Here, we identify a novel proteolysis6 (prt6) mutant allele, named greening after extended darkness1 (ged1), which was previously discovered in a screen for genomes uncoupled-like mutants and shows the ability to withstand long periods of darkness at the seedling stage. Interestingly, this ethyl methanesulfonate-derived mutant shows unusual chromosomal rearrangement instead of a point mutation. Furthermore, the sensitivity of N-end rule pathway mutants ged1 and prt6-1 to submergence was studied in more detail to understand previously contradicting experiments on this topic. Finally, it was shown that mutants for the N-end rule pathway are generally more tolerant to starvation conditions, such as prolonged darkness or submergence, which was partially associated with carbohydrate conservation.
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Affiliation(s)
- Willi Riber
- Plant Physiology, University Bayreuth, 95440 Bayreuth, Germany (W.R., J.T.M., A.M.);Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands (E.J.W.V.); andPlant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands (R.S., L.A.C.J.V.)
| | - Jana T Müller
- Plant Physiology, University Bayreuth, 95440 Bayreuth, Germany (W.R., J.T.M., A.M.);Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands (E.J.W.V.); andPlant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands (R.S., L.A.C.J.V.)
| | - Eric J W Visser
- Plant Physiology, University Bayreuth, 95440 Bayreuth, Germany (W.R., J.T.M., A.M.);Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands (E.J.W.V.); andPlant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands (R.S., L.A.C.J.V.)
| | - Rashmi Sasidharan
- Plant Physiology, University Bayreuth, 95440 Bayreuth, Germany (W.R., J.T.M., A.M.);Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands (E.J.W.V.); andPlant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands (R.S., L.A.C.J.V.)
| | - Laurentius A C J Voesenek
- Plant Physiology, University Bayreuth, 95440 Bayreuth, Germany (W.R., J.T.M., A.M.);Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands (E.J.W.V.); andPlant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands (R.S., L.A.C.J.V.)
| | - Angelika Mustroph
- Plant Physiology, University Bayreuth, 95440 Bayreuth, Germany (W.R., J.T.M., A.M.);Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University, 6525 AJ Nijmegen, The Netherlands (E.J.W.V.); andPlant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands (R.S., L.A.C.J.V.)
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Ruckle ME, Burgoon LD, Lawrence LA, Sinkler CA, Larkin RM. Plastids are major regulators of light signaling in Arabidopsis. PLANT PHYSIOLOGY 2012; 159:366-90. [PMID: 22383539 PMCID: PMC3375971 DOI: 10.1104/pp.112.193599] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 02/29/2012] [Indexed: 05/20/2023]
Abstract
We previously provided evidence that plastid signaling regulates the downstream components of a light signaling network and that this signal integration coordinates chloroplast biogenesis with both the light environment and development by regulating gene expression. We tested these ideas by analyzing light- and plastid-regulated transcriptomes in Arabidopsis (Arabidopsis thaliana). We found that the enrichment of Gene Ontology terms in these transcriptomes is consistent with the integration of light and plastid signaling (1) down-regulating photosynthesis and inducing both repair and stress tolerance in dysfunctional chloroplasts and (2) helping coordinate processes such as growth, the circadian rhythm, and stress responses with the degree of chloroplast function. We then tested whether factors that contribute to this signal integration are also regulated by light and plastid signals by characterizing T-DNA insertion alleles of genes that are regulated by light and plastid signaling and that encode proteins that are annotated as contributing to signaling, transcription, or no known function. We found that a high proportion of these mutant alleles induce chloroplast biogenesis during deetiolation. We quantified the expression of four photosynthesis-related genes in seven of these enhanced deetiolation (end) mutants and found that photosynthesis-related gene expression is attenuated. This attenuation is particularly striking for Photosystem II subunit S expression. We conclude that the integration of light and plastid signaling regulates a number of END genes that help optimize chloroplast function and that at least some END genes affect photosynthesis-related gene expression.
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Affiliation(s)
| | | | | | | | - Robert M. Larkin
- Michigan State University-Department of Energy Plant Research Laboratory (M.E.R., L.A.L., C.A.S., R.M.L.), Department of Biochemistry and Molecular Biology (M.E.R., L.D.B., R.M.L.), and Gene Expression in Development and Disease Initiative (L.D.B.), Michigan State University, East Lansing, Michigan 48824
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14
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Isemer R, Krause K, Grabe N, Kitahata N, Asami T, Krupinska K. Plastid Located WHIRLY1 Enhances the Responsiveness of Arabidopsis Seedlings Toward Abscisic Acid. FRONTIERS IN PLANT SCIENCE 2012; 3:283. [PMID: 23269926 PMCID: PMC3529394 DOI: 10.3389/fpls.2012.00283] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 11/30/2012] [Indexed: 05/20/2023]
Abstract
WHIRLY1 is a protein that can be translocated from the plastids to the nucleus, making it an ideal candidate for communicating information between these two compartments. Mutants of Arabidopsis thaliana lacking WHIRLY1 (why1) were shown to have a reduced sensitivity toward salicylic acid (SA) and abscisic acid (ABA) during germination. Germination assays in the presence of abamine, an inhibitor of ABA biosynthesis, revealed that the effect of SA on germination was in fact caused by a concomitant stimulation of ABA biosynthesis. In order to distinguish whether the plastid or the nuclear isoform of WHIRLY1 is adjusting the responsiveness toward ABA, sequences encoding either the complete WHIRLY1 protein or a truncated form lacking the plastid transit peptide were overexpressed in the why1 mutant background. In plants overexpressing the full-length sequence, WHIRLY1 accumulated in both plastids and the nucleus, whereas in plants overexpressing the truncated sequence, WHIRLY1 accumulated exclusively in the nucleus. Seedlings containing recombinant WHIRLY1 in both compartments were hypersensitive toward ABA. In contrast, seedlings possessing only the nuclear form of WHIRLY1 were as insensitive toward ABA as the why1 mutants. ABA was furthermore shown to lower the rate of germination of wildtype seeds even in the presence of abamine which is known to inhibit the formation of xanthoxin, the plastid located precursor of ABA. From this we conclude that plastid located WHIRLY1 enhances the responsiveness of seeds toward ABA even when ABA is supplied exogenously.
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Affiliation(s)
- Rena Isemer
- Institute of Botany, Christian-Albrechts-University of KielKiel, Germany
| | - Kirsten Krause
- Department of Arctic and Marine Biology, University of TromsøTromsø, Norway
| | - Nils Grabe
- Institute of Botany, Christian-Albrechts-University of KielKiel, Germany
| | - Nobutaka Kitahata
- Department of Applied Biological Chemistry, The University of TokyoTokyo, Japan
| | - Tadao Asami
- Department of Applied Biological Chemistry, The University of TokyoTokyo, Japan
| | - Karin Krupinska
- Institute of Botany, Christian-Albrechts-University of KielKiel, Germany
- *Correspondence: Karin Krupinska, Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstrasse 40, 24098 Kiel, Germany. e-mail:
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Koops P, Pelser S, Ignatz M, Klose C, Marrocco-Selden K, Kretsch T. EDL3 is an F-box protein involved in the regulation of abscisic acid signalling in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:5547-60. [PMID: 21831845 PMCID: PMC3223051 DOI: 10.1093/jxb/err236] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 07/04/2011] [Accepted: 07/05/2011] [Indexed: 05/19/2023]
Abstract
The EID1-like protein 3 (EDL3) shows high similarity to EID1 (Empfindlicher im dunkelroten Licht 1), an F-box protein that functions as a negative regulator in the signalling cascade downstream of the phytochrome A photoreceptor in Arabidopsis thaliana. Analyses revealed a strong and rapid induction of EDL3 gene expression under osmotic stress, high salinity, and upon abscisic acid (ABA) application. Therefore, it was speculated that EDL3 is involved in the regulation of responses controlled by this plant hormone, which not only regulates many aspects of plant development but also integrates responses towards temperature, drought, osmotic, and salt stresses. Physiological data obtained with over-expresser lines and a conditional knock-down mutant demonstrated that EDL3 functions as a positive regulator in ABA-dependent signalling cascades that control seed germination, root growth, greening of etiolated seedlings, and transition to flowering. Results further demonstrate that EDL3 regulates anthocyanin accumulation under drought stress. The observed effects on physiological responses fit to tissue-specific expression patterns obtained with EDL3-promoter:GUS lines. Bimolecular Fluorescence Complementation assays and yeast two-hybrid analyses showed that EDL3 carries a functional F-box domain. Thus, the protein is presumed to act as a component of a ubiquitin ligase complex that specifically directs negatively acting factors in ABA signalling to degradation via the proteasome.
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Affiliation(s)
| | | | | | | | | | - Thomas Kretsch
- Albert-Ludwigs-Universität Freiburg, Faculty of Biology, Institut für Biologie 2/Botanik, Schänzlestrasse 1, D-79104 Freiburg i. Br., Germany
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Voigt C, Oster U, Börnke F, Jahns P, Dietz KJ, Leister D, Kleine T. In-depth analysis of the distinctive effects of norflurazon implies that tetrapyrrole biosynthesis, organellar gene expression and ABA cooperate in the GUN-type of plastid signalling. PHYSIOLOGIA PLANTARUM 2010; 138:503-19. [PMID: 20028479 DOI: 10.1111/j.1399-3054.2009.01343.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Application of norflurazon (NF) damages plastids, induces photobleaching and represses expression of the nuclear LHCB1.2 gene encoding a light-harvesting protein. In genomes uncoupled (gun) mutants, LHCB1.2 expression is maintained in the presence of NF. The mutants gun2, gun4 and gun5 exhibit perturbations in tetrapyrrole biosynthesis, but gun1 is defective in organellar gene expression (OGE). How gun mutations affect nuclear gene expression (NGE) and why the signals elicited by the two types evoke the same response remains unknown. Here we show that the carotenoid biosynthesis inhibitors amitrole and flurochloridone can replace NF in gun assays, whereas novel tetrapyrrole pathway mutations do not provoke a gun phenotype. Changes in haem levels also do not account for LHCB1.2 derepression in NF-treated gun mutants. Pigment measurements indicated that gun mutants are not resistant to NF, but gun2, gun4 and gun5 retain low levels of lutein, as well as of neoxanthin and violaxanthin, the precursors of abscisic acid (ABA). This might explain the enhanced ABA sensitivity of gun4 and gun5 plants found in germination assays. Metabolite profiling and analyses of reactive oxygen species and cellular redox state failed to suggest a link between gun mutations and altered LHCB1.2 expression. However, in contrast to NF-treated wild-type plants, gun mutants retain to a marked extent the capability to express the plastome-encoded proteins AtpB and RbcL. This, together with the finding that application of ABA can partially restore LHCB1.2 expression in NF-treated wild-type plants, supports the view that tetrapyrrole, OGE and ABA signalling are interconnected.
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Affiliation(s)
- Christian Voigt
- Lehrstuhl für Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität, Planegg-Martinsried, Germany
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