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Geng R, Li X, Huang J, Zhou W. The chloroplast singlet oxygen-triggered biosynthesis of salicylic acid and jasmonic acid is mediated by EX1 and GUN1 in Arabidopsis. PLANT, CELL & ENVIRONMENT 2024; 47:2852-2864. [PMID: 38600785 DOI: 10.1111/pce.14910] [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: 10/26/2023] [Revised: 02/29/2024] [Accepted: 03/29/2024] [Indexed: 04/12/2024]
Abstract
Reactive oxygen species (ROS) and defence hormones like salicylic acid (SA) and jasmonic acid (JA) play pivotal roles in triggering cell death. However, the precise mechanism governing the interaction between ROS and SA/JA remains elusive. Recently, our research revealed that RNAi mutants with suppressed expression of PROGRAMMED CELL DEATH8 (PCD8) exhibit an overabundance of tetrapyrrole intermediates, particularly uroporphyrinogen III (Uro III), leading to the accumulation of singlet oxygen (1O2) during the transition from darkness to light, thereby instigating leaf necrosis. In this investigation, we uncovered that 1O2 stimulates biosynthesis of SA and JA, activating SA/JA signalling and the expression of responsive genes in PCD8 RNAi (pcd8) mutants. Introducing NahG or knocking out PAD4 or NPR1 significantly alleviates the cell death phenotype of pcd8 mutants, while coi1 partially mitigates the pcd8 phenotype. Further exploration revealed that EX1 and GUN1 can partially rescue the pcd8 phenotype by reducing the levels of Uro III and 1O2. Notably, mutations in EX1 mutations but not GUN1, substantially diminish SA content in pcd8 mutants compared to the wild type, implying that EX1 acts as the primary mediator of 1O2 signalling-mediated SA biosynthesis. Moreover, the triple ex1 gun1 pcd8 displays a phenotype similar to ex1. Overall, our findings underscore that the 1O2-induced cell death phenotype requires EX1/GUN1-mediated retrograde signalling in pcd8 mutants, providing novel insights into the interplay between ROS and SA/JA.
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Affiliation(s)
- Rudan Geng
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Xia Li
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jirong Huang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Wenbin Zhou
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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Wittmann D, Geigenberger P, Grimm B. NTRC and TRX-f Coordinately Affect the Levels of Enzymes of Chlorophyll Biosynthesis in a Light-Dependent Manner. Cells 2023; 12:1670. [PMID: 37371140 DOI: 10.3390/cells12121670] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/02/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Redox regulation of plastid gene expression and different metabolic pathways promotes many activities of redox-sensitive proteins. We address the question of how the plastid redox state and the contributing reducing enzymes control the enzymes of tetrapyrrole biosynthesis (TBS). In higher plants, this metabolic pathway serves to produce chlorophyll and heme, among other essential end products. Because of the strictly light-dependent synthesis of chlorophyll, tight control of TBS requires a diurnal balanced supply of the precursor 5-aminolevulinic acid (ALA) to prevent the accumulation of photoreactive metabolic intermediates in darkness. We report on some TBS enzymes that accumulate in a light intensity-dependent manner, and their contents decrease under oxidizing conditions of darkness, low light conditions, or in the absence of NADPH-dependent thioredoxin reductase (NTRC) and thioredoxin f1 (TRX-f1). Analysis of single and double trxf1 and ntrc mutants revealed a decreased content of the early TBS enzymes glutamyl-tRNA reductase (GluTR) and 5-aminolevulinic acid dehydratase (ALAD) instead of an exclusive decrease in enzyme activity. This effect was dependent on light conditions and strongly attenuated after transfer to high light intensities. Thus, it is suggested that a deficiency of plastid-localized thiol-redox transmitters leads to enhanced degradation of TBS enzymes rather than being directly caused by lower catalytic activity. The effects of the proteolytic activity of the Clp protease on TBS enzymes were studied by using Clp subunit-deficient mutants. The simultaneous lack of TRX and Clp activities in double mutants confirms the Clp-induced degradation of some TBS proteins in the absence of reductive activity of TRXs. In addition, we verified previous observations that decreased chlorophyll and heme levels in ntrc could be reverted to WT levels in the ntrc/Δ2cp triple mutant. The decreased synthesis of 5-aminolevulinic acid and porphobilinogen in ntrc was completely restored in ntrc/Δ2cp and correlated with WT-like levels of GluTR, ALAD, and other TBS proteins.
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Affiliation(s)
- Daniel Wittmann
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Peter Geigenberger
- Department Biology I, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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Youssef WA, Feil R, Saint-Sorny M, Johnson X, Lunn JE, Grimm B, Brzezowski P. Singlet oxygen-induced signalling depends on the metabolic status of the Chlamydomonas reinhardtii cell. Commun Biol 2023; 6:529. [PMID: 37193883 DOI: 10.1038/s42003-023-04872-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 04/24/2023] [Indexed: 05/18/2023] Open
Abstract
Using a mutant screen, we identified trehalose 6-phosphate phosphatase 1 (TSPP1) as a functional enzyme dephosphorylating trehalose 6-phosphate (Tre6P) to trehalose in Chlamydomonas reinhardtii. The tspp1 knock-out results in reprogramming of the cell metabolism via altered transcriptome. As a secondary effect, tspp1 also shows impairment in 1O2-induced chloroplast retrograde signalling. From transcriptomic analysis and metabolite profiling, we conclude that accumulation or deficiency of certain metabolites directly affect 1O2-signalling. 1O2-inducible GLUTATHIONE PEROXIDASE 5 (GPX5) gene expression is suppressed by increased content of fumarate and 2-oxoglutarate, intermediates in the tricarboxylic acid cycle (TCA cycle) in mitochondria and dicarboxylate metabolism in the cytosol, but also myo-inositol, involved in inositol phosphate metabolism and phosphatidylinositol signalling system. Application of another TCA cycle intermediate, aconitate, recovers 1O2-signalling and GPX5 expression in otherwise aconitate-deficient tspp1. Genes encoding known essential components of chloroplast-to-nucleus 1O2-signalling, PSBP2, MBS, and SAK1, show decreased transcript levels in tspp1, which also can be rescued by exogenous application of aconitate. We demonstrate that chloroplast retrograde signalling involving 1O2 depends on mitochondrial and cytosolic processes and that the metabolic status of the cell determines the response to 1O2.
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Affiliation(s)
- Waeil Al Youssef
- Pflanzenphysiologie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | - Maureen Saint-Sorny
- Photosynthesis and Environment Team, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Institut de Biosciences et Biotechnologies d'Aix-Marseille, Aix-Marseille Université, UMR 7265, CEA Cadarache, F-13108, Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- Photosynthesis and Environment Team, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Institut de Biosciences et Biotechnologies d'Aix-Marseille, Aix-Marseille Université, UMR 7265, CEA Cadarache, F-13108, Saint-Paul-lez-Durance, France
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | - Bernhard Grimm
- Pflanzenphysiologie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Pawel Brzezowski
- Pflanzenphysiologie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.
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Zhang C, Ma C, Zhu L, Yao M. Simultaneous determination of protoporphyrin IX and magnesium protoporphyrin IX in Arabidopsis thaliana and Camellia sinensis using UPLC-MS/MS. PLANT METHODS 2023; 19:34. [PMID: 36998023 PMCID: PMC10061815 DOI: 10.1186/s13007-023-01008-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUNDS Insertion of Mg2+ into protoporphyrin IX (PPIX) to produce magnesium-protoporphyrin IX (Mg-PPIX) was the first step toward chlorophyll biosynthesis, which not only imparts plants green pigmentation but underpins photosynthesis. Plants that blocked the conversion of PPIX to Mg-PPIX displayed yellowish or albino-lethal phenotypes. However, the lack of systematic study of the detection method and the metabolic difference between species have caused the research on chloroplast retrograde signaling controversial for a long time. RESULTS An advanced and sensitive UPLC-MS/MS strategy for determining PPIX and Mg-PPIX was established in two metabolic different plants, Arabidopsis thaliana (Columbia-0) and Camellia sinensis var. sinensis. Two metabolites could be extracted by 80% acetone (v/v) and 20% 0.1 M NH4OH (v/v) without hexane washing. Since the Mg-PPIX could be substantially de-metalized into PPIX in acidic conditions, analysis was carried out by UPLC-MS/MS with 0.1% ammonia (v/v) and 0.1% ammonium acetonitrile (v/v) as mobile phases using negative ion multiple reaction monitoring modes. Interestingly, it could be easier to monitor these two compounds in dehydrated samples rather than in fresh samples. Validation was performed in spiked samples and mean recoveries ranged from 70.5 to 916%, and the intra-day and inter-day variations were less than 7.5 and 10.9%, respectively. The limit of detection was 0.01 mg·kg- 1 and the limit of quantification was 0.05 mg·kg- 1. The contents of PPIX (1.67 ± 0.12 mg·kg- 1) and Mg-PPIX (3.37 ± 0.10 mg·kg- 1) in tea were significantly higher than in Arabidopsis (PPIX: 0.05 ± 0.02 mg·kg- 1; Mg-PPIX: 0.08 ± 0.01 mg·kg- 1) and they were only detected in the leaf. CONCLUSIONS Our study establishes a universal and reliable method for determining PPIX and Mg-PPIX in two plants using UPLC-MS/MS. This procedure will facilitate studying chlorophyll metabolism and natural chlorophyll production.
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Affiliation(s)
- Chenyu Zhang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, 310008 China
| | - Chunlei Ma
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, 310008 China
| | - Li Zhu
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, 310008 China
| | - Mingzhe Yao
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, 310008 China
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Bernal L, Luján‐Soto E, Fajardo‐Hernández CA, Coello P, Figueroa M, Martínez‐Barajas E. Starch degradation in the bean fruit pericarp is characterized by an increase in maltose metabolism. PHYSIOLOGIA PLANTARUM 2022; 174:e13836. [PMID: 36453084 PMCID: PMC10107891 DOI: 10.1111/ppl.13836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
The bean fruit pericarp accumulates a significant amount of starch, which starts to be degraded 20 days after anthesis (DAA) when seed growth becomes exponential. This period is also characterized by the progressive senescence of the fruit pericarp. However, the chloroplasts maintained their integrity, indicating that starch degradation is a compartmentalized process. The process coincided with a transient increase in maltose and sucrose levels, suggesting that β-amylase is responsible for starch degradation. Starch degradation in the bean fruit pericarp is also characterized by a large increase in starch phosphorylation, as well as in the activities of cytosolic disproportionating enzyme 2 (DPE2, EC 2.4.1.25) and glucan phosphorylase (PHO2, EC 2.4.1.1). This suggests that the rate of starch degradation in the bean fruit pericarp 20 DAA is dependent on the transformation of starch to a better substrate for β-amylase and the increase in the rate of cytosolic metabolism of maltose.
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Affiliation(s)
- Lilia Bernal
- Departamento de Bioquímica, Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | - Eduardo Luján‐Soto
- Departamento de Bioquímica, Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | | | - Patricia Coello
- Departamento de Bioquímica, Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | - Mario Figueroa
- Departamento de Farmacia, Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | - Eleazar Martínez‐Barajas
- Departamento de Bioquímica, Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
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Yuan J, Ma T, Ji S, Hedtke B, Grimm B, Lin R. Two chloroplast-localized MORF proteins act as chaperones to maintain tetrapyrrole biosynthesis. THE NEW PHYTOLOGIST 2022; 235:1868-1883. [PMID: 35615903 DOI: 10.1111/nph.18273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Tetrapyrroles have essential functions as pigments and cofactors during plant growth and development, and the tetrapyrrole biosynthesis pathway is tightly controlled. Multiple organellar RNA editing factors (MORFs) are required for editing of a wide variety of RNA sites in chloroplasts and mitochondria, but their biochemical properties remain elusive. Here, we uncovered the roles of chloroplast-localized MORF2 and MORF9 in modulating tetrapyrrole biosynthesis and embryogenesis in Arabidopsis thaliana. The lack or reduced transcripts of MORF2 or MORF9 significantly affected biosynthesis of the tetrapyrrole precursor 5-aminolevulinic acid and accumulation of Chl and other tetrapyrrole intermediates. MORF2 directly interacts with multiple tetrapyrrole biosynthesis enzymes and regulators, including NADPH:PROTOCHLOROPHYLLIDE OXIDOREDUCTASE B (PORB) and GENOMES UNCOUPLED4 (GUN4). Strikingly, MORF2 and MORF9 display holdase chaperone activity, alleviate the aggregation of PORB in vitro, and are essential for POR accumulation in vivo. Moreover, both MORF2 and MORF9 significantly stimulate magnesium chelatase activity. Our findings reveal a previously unknown biochemical property of MORF proteins as chaperones and point to a new layer of post-translational control of the tightly regulated tetrapyrrole biosynthesis in plants.
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Affiliation(s)
- Jiarui Yuan
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tingting Ma
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Shuiling Ji
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Boris Hedtke
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Rongcheng Lin
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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7
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Fisher KE, Krishnamoorthy P, Joens MS, Chory J, Fitzpatrick JAJ, Woodson JD. Singlet Oxygen Leads to Structural Changes to Chloroplasts during their Degradation in the Arabidopsis thaliana plastid ferrochelatase two Mutant. PLANT & CELL PHYSIOLOGY 2022; 63:248-264. [PMID: 34850209 DOI: 10.1093/pcp/pcab167] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/01/2021] [Accepted: 11/22/2021] [Indexed: 06/13/2023]
Abstract
During stress, chloroplasts produce large amounts of reactive oxygen species (ROS). Chloroplasts also contain many nutrients, including 80% of a leaf's nitrogen supply. Therefore, to protect cells from photo-oxidative damage and to redistribute nutrients to sink tissues, chloroplasts are prime targets for degradation. Multiple chloroplast degradation pathways are induced by photo-oxidative stress or nutrient starvation, but the mechanisms by which damaged or senescing chloroplasts are identified, transported to the central vacuole and degraded are poorly defined. Here, we investigated the structures involved with degrading chloroplasts induced by the ROS singlet oxygen (1O2) in the Arabidopsis thaliana plastid ferrochelatase two (fc2) mutant. Under mild 1O2 stress, most fc2 chloroplasts appeared normal, but had reduced starch content. A subset of chloroplasts was degrading, and some protruded into the central vacuole via 'blebbing' structures. A 3D electron microscopy analysis demonstrated that up to 35% of degrading chloroplasts contained such structures. While the location of a chloroplast within a cell did not affect the likelihood of its degradation, chloroplasts in spongy mesophyll cells were degraded at a higher rate than those in palisade mesophyll cells. To determine if degrading chloroplasts have unique structural characteristics, allowing them to be distinguished from healthy chloroplasts, we analyzed fc2 seedlings grown under different levels of photo-oxidative stress. A correlation was observed among chloroplast swelling, 1O2 signaling and the state of degradation. Finally, plastoglobule (PG) enzymes involved in chloroplast disassembly were upregulated while PGs increased their association with the thylakoid grana, implicating an interaction between 1O2-induced chloroplast degradation and senescence pathways.
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Affiliation(s)
- Karen E Fisher
- The School of Plant Sciences, University of Arizona, 1140 E South Campus Dr., Tucson, AZ 85721, USA
| | - Praveen Krishnamoorthy
- Washington University Center for Cellular Imaging, Washington University School of Medicine, 660 W. Euclid Avenue, St. Louis, MO 63110, USA
| | | | - Joanne Chory
- Plant Biology Laboratory and the Howard Hughes Medical Institute, The Salk Institute, 10010 N Torrey Pines Rd., La Jolla, CA 92037, USA
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, 660 W. Euclid Avenue, St. Louis, MO 63110, USA
- Departments of Cell Biology & Physiology and Neuroscience, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Jesse D Woodson
- The School of Plant Sciences, University of Arizona, 1140 E South Campus Dr., Tucson, AZ 85721, USA
- Washington University Center for Cellular Imaging, Washington University School of Medicine, 660 W. Euclid Avenue, St. Louis, MO 63110, USA
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8
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Alamdari K, Fisher KE, Tano DW, Rai S, Palos K, Nelson ADL, Woodson JD. Chloroplast quality control pathways are dependent on plastid DNA synthesis and nucleotides provided by cytidine triphosphate synthase two. THE NEW PHYTOLOGIST 2021; 231:1431-1448. [PMID: 33993494 DOI: 10.1111/nph.17467] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
Reactive oxygen species (ROS) produced in chloroplasts cause oxidative damage, but also signal to initiate chloroplast quality control pathways, cell death, and gene expression. The Arabidopsis thaliana plastid ferrochelatase two (fc2) mutant produces the ROS singlet oxygen in chloroplasts that activates such signaling pathways, but the mechanisms are largely unknown. Here we characterize one fc2 suppressor mutation and map it to CYTIDINE TRIPHOSPHATE SYNTHASE TWO (CTPS2), which encodes one of five enzymes in Arabidopsis necessary for de novo cytoplasmic CTP (and dCTP) synthesis. The ctps2 mutation reduces chloroplast transcripts and DNA content without similarly affecting mitochondria. Chloroplast nucleic acid content and singlet oxygen signaling are restored by exogenous feeding of the dCTP precursor deoxycytidine, suggesting ctps2 blocks signaling by limiting nucleotides for chloroplast genome maintenance. An investigation of CTPS orthologs in Brassicaceae showed CTPS2 is a member of an ancient lineage distinct from CTPS3. Complementation studies confirmed this analysis; CTPS3 was unable to compensate for CTPS2 function in providing nucleotides for chloroplast DNA and signaling. Our studies link cytoplasmic nucleotide metabolism with chloroplast quality control pathways. Such a connection is achieved by a conserved clade of CTPS enzymes that provide nucleotides for chloroplast function, thereby allowing stress signaling to occur.
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Affiliation(s)
- Kamran Alamdari
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Karen E Fisher
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - David W Tano
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Snigdha Rai
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Kyle Palos
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | | | - Jesse D Woodson
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
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Hou Z, Pang X, Hedtke B, Grimm B. In vivo functional analysis of the structural domains of FLUORESCENT (FLU). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:360-376. [PMID: 33901334 DOI: 10.1111/tpj.15293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/12/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
The control of chlorophyll (Chl) synthesis in angiosperms depends on the light-operating enzyme protochlorophyllide oxidoreductase (POR). The interruption of Chl synthesis during darkness requires suppression of the synthesis of 5-aminolevulinic acid (ALA), the first precursor molecule specific for Chl synthesis. The inactivation of glutamyl-tRNA reductase (GluTR), the first enzyme in tetrapyrrole biosynthesis, accomplished the decreased ALA synthesis by the membrane-bound protein FLUORESCENT (FLU) and prevents overaccumulation of protochlorophyllide (Pchlide) in the dark. We set out to elucidate the molecular mechanism of FLU-mediated inhibition of ALA synthesis, and explored the role of each of the three structural domains of mature FLU, the transmembrane, coiled-coil and tetratricopeptide repeat (TPR) domains, in this process. Efforts to rescue the FLU knock-out mutant with truncated FLU peptides revealed that, on its own, the TPR domain is insufficient to inactivate GluTR, although tight binding of the TPR domain to GluTR was detected. A truncated FLU peptide consisting of transmembrane and TPR domains also failed to inactivate GluTR in the dark. Similarly, suppression of ALA synthesis could not be achieved by combining the coiled-coil and TPR domains. Interaction studies revealed that binding of GluTR and POR to FLU is essential for inhibiting ALA synthesis. These results imply that all three FLU domains are required for the repression of ALA synthesis, in order to avoid the overaccumulation of Pchlide in the dark. Only complete FLU ensures the formation of a membrane-bound ternary complex consisting at least of FLU, GluTR and POR to repress ALA synthesis.
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Affiliation(s)
- Zhiwei Hou
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
| | - Xiaoqing Pang
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
| | - Boris Hedtke
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
| | - Bernhard Grimm
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
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10
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Xue Y, Li X, Mao M, He Y, Owusu Adjei M, Zhou X, Hu H, Liu J, Li X, Ma J. AbhemC encoding porphobilinogen deaminase plays an important role in chlorophyll biosynthesis and function in albino Ananas comosus var. bracteatus leaves. PeerJ 2021; 9:e11118. [PMID: 33850657 PMCID: PMC8018242 DOI: 10.7717/peerj.11118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 02/25/2021] [Indexed: 11/29/2022] Open
Abstract
Background The chimeric leaves of Ananas comosus var. bracteatus are composed of normal green parts (Grs) and albino white parts (Whs). Although the underlying mechanism of albinism in A. comosus var. bracteatus leaves is not fully understood, it is likely associated with the chlorophyll (Chl) biosynthesis. In this biosynthetic process, porphobilinogen deaminase (PBGD) plays a crucial role by catalyzing the conversion of porphobilinogen (PBG) to uroporphyrinogen III (Urogen III). Therefore, its encoding gene AbhemC was investigated here in association with Chl biosynthesis and albinism in chimeric A. comosus var. bracteatus leaves. Methods The Chl content, main Chl biosynthesis precursor content, and main enzyme activity were determined and compared between the Whs and Grs of A. comosus var. bracteatus leaves. In addition, AbhemC was cloned and its transcriptional expression and prokaryotic protein expression were analyzed. Furthermore, RNAi-mediated silencing of AbhemC was produced and assessed in tobacco plants. Results The concentration of Chl a and Chl b in the Grs was significantly higher than that in the Whs, respectively. Additionally, the content of the Chl biosynthesis precursor Urogen III decreased significantly in the Whs compared with the Grs. Thus, the transition of PBG to Urogen III may be the first rate-limiting step leading to albinism in the chimeric leaves of A. comosus var. bracteatus. The gene AbhemC comprised 1,135 bp and was encoded into a protein with 371 amino acids; phylogenetically, AbhemC was most closely related to hemC of pineapple. Prokaryotic expression and in vitro enzyme activity analysis showed that the cloned mRNA sequence of AbhemC was successfully integrated and had PBGD activity. Compared with control plants, transgenic tobacco leaves with pFGC5941-AbhemC-RNAi vector were substantially less green with significantly reduced hemC expression and Chl content, as well as reduced PBGD enzyme activity and significantly decreased content of Chl biosynthesis precursors from Urogen III onwards. Our results suggest that the absence of hemC expression reduces the enzyme activity of PBGD, which blocks the transition of PBG to Urogen III, and in turn suppresses Chl synthesis leading to the pale-green leaf color. Therefore, we suggest that AbhemC plays an important role in Chl synthesis and may be an important factor in the albinism of A. comosus var. bracteatus leaves.
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Affiliation(s)
- Yanbin Xue
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China.,College of Biology and Food Engineering, Chongqing Three Gorges College, Chongqing, China
| | - Xia Li
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Meiqin Mao
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Yehua He
- South China Agricultural University, Guangzhou, China
| | - Mark Owusu Adjei
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Xuzixin Zhou
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Hao Hu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Jiawen Liu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Xi Li
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Jun Ma
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
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11
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Alamdari K, Fisher KE, Sinson AB, Chory J, Woodson JD. Roles for the chloroplast-localized pentatricopeptide repeat protein 30 and the 'mitochondrial' transcription termination factor 9 in chloroplast quality control. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:735-751. [PMID: 32779277 DOI: 10.1111/tpj.14963] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 07/20/2020] [Indexed: 05/11/2023]
Abstract
Chloroplasts constantly experience photo-oxidative stress while performing photosynthesis. This is particularly true under abiotic stresses that lead to the accumulation of reactive oxygen species (ROS) which oxidize DNA, proteins and lipids. Reactive oxygen species can also act as signals to induce acclimation through chloroplast degradation, cell death and nuclear gene expression. To better understand the mechanisms behind ROS signaling from chloroplasts, we have used the Arabidopsis thaliana mutant plastid ferrochelatase two (fc2) that conditionally accumulates the ROS singlet oxygen (1 O2 ) leading to chloroplast degradation and eventually cell death. Here we have mapped mutations that suppress chloroplast degradation in the fc2 mutant and demonstrate that they affect two independent loci (PPR30 and mTERF9) encoding chloroplast proteins predicted to be involved in post-transcriptional gene expression. These mutants exhibited broadly reduced chloroplast gene expression, impaired chloroplast development and reduced chloroplast stress signaling. Levels of 1 O2 , however, could be uncoupled from chloroplast degradation, suggesting that PPR30 and mTERF9 are involved in ROS signaling pathways. In the wild-type background, ppr30 and mTERF9 mutants were also observed to be less susceptible to cell death induced by excess light stress. While broad inhibition of plastid transcription with rifampicin was also able to suppress cell death in fc2 mutants, specific reductions in plastid gene expression using other mutations was not always sufficient. Together these results suggest that plastid gene expression, or the expression of specific plastid genes by PPR30 and mTERF0, is a necessary prerequisite for chloroplasts to activate the 1 O2 signaling pathways to induce chloroplast quality control pathways and/or cell death.
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Affiliation(s)
- Kamran Alamdari
- The School of Plant Sciences, University of Arizona, 1140 E. South Campus Drive, 303 Forbes Building, Tucson, AZ, 85721, USA
| | - Karen E Fisher
- The School of Plant Sciences, University of Arizona, 1140 E. South Campus Drive, 303 Forbes Building, Tucson, AZ, 85721, USA
| | - Andrew B Sinson
- The Division of Biological Sciences, The University of California San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
- Plant Biology Laboratory, The Salk Institute, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Joanne Chory
- Plant Biology Laboratory, The Salk Institute, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
- Howard Hughes Medical Institute, The Salk Institute, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Jesse D Woodson
- The School of Plant Sciences, University of Arizona, 1140 E. South Campus Drive, 303 Forbes Building, Tucson, AZ, 85721, USA
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12
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Grieco M, Roustan V, Dermendjiev G, Rantala S, Jain A, Leonardelli M, Neumann K, Berger V, Engelmeier D, Bachmann G, Ebersberger I, Aro E, Weckwerth W, Teige M. Adjustment of photosynthetic activity to drought and fluctuating light in wheat. PLANT, CELL & ENVIRONMENT 2020; 43:1484-1500. [PMID: 32176335 PMCID: PMC7384038 DOI: 10.1111/pce.13756] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 03/02/2020] [Indexed: 05/24/2023]
Abstract
Drought is a major cause of losses in crop yield. Under field conditions, plants exposed to drought are usually also experiencing rapid changes in light intensity. Accordingly, plants need to acclimate to both, drought and light stress. Two crucial mechanisms in plant acclimation to changes in light conditions comprise thylakoid protein phosphorylation and dissipation of light energy as heat by non-photochemical quenching (NPQ). Here, we analyzed the acclimation efficacy of two different wheat varieties, by applying fluctuating light for analysis of plants, which had been subjected to a slowly developing drought stress as it usually occurs in the field. This novel approach allowed us to distinguish four drought phases, which are critical for grain yield, and to discover acclimatory responses which are independent of photodamage. In short-term, under fluctuating light, the slowdown of NPQ relaxation adjusts the photosynthetic activity to the reduced metabolic capacity. In long-term, the photosynthetic machinery acquires a drought-specific configuration by changing the PSII-LHCII phosphorylation pattern together with protein stoichiometry. Therefore, the fine-tuning of NPQ relaxation and PSII-LHCII phosphorylation pattern represent promising traits for future crop breeding strategies.
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Affiliation(s)
- Michele Grieco
- Ecogenomics and Systems BiologyUniversity of ViennaViennaAustria
- Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)SeelandGermany
| | - Valentin Roustan
- Ecogenomics and Systems BiologyUniversity of ViennaViennaAustria
| | | | - Sanna Rantala
- Molecular Plant BiologyUniversity of TurkuTurkuFinland
| | - Arpit Jain
- Applied Bioinformatics GroupInstitute of Cell Biology and Neuroscience, Goethe‐University FrankfurtFrankfurtGermany
| | | | - Kerstin Neumann
- Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)SeelandGermany
| | - Vitus Berger
- Ecogenomics and Systems BiologyUniversity of ViennaViennaAustria
| | - Doris Engelmeier
- Ecogenomics and Systems BiologyUniversity of ViennaViennaAustria
| | - Gert Bachmann
- Ecogenomics and Systems BiologyUniversity of ViennaViennaAustria
| | - Ingo Ebersberger
- Applied Bioinformatics GroupInstitute of Cell Biology and Neuroscience, Goethe‐University FrankfurtFrankfurtGermany
- Senckenberg Biodiversity and Climate Research Centre (S‐BIK‐F)FrankfurtGermany
- LOEWE Center for Translational Biodiversity GenomicsFrankfurtGermany
| | - Eva‐Mari Aro
- Molecular Plant BiologyUniversity of TurkuTurkuFinland
| | - Wolfram Weckwerth
- Ecogenomics and Systems BiologyUniversity of ViennaViennaAustria
- Vienna Metabolomics Center (VIME)University of ViennaViennaAustria
| | - Markus Teige
- Ecogenomics and Systems BiologyUniversity of ViennaViennaAustria
- Max Perutz Labs, Department of Biochemistry & Cell BiologyUniversity of ViennaViennaAustria
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13
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Wang P, Richter AS, Kleeberg JRW, Geimer S, Grimm B. Post-translational coordination of chlorophyll biosynthesis and breakdown by BCMs maintains chlorophyll homeostasis during leaf development. Nat Commun 2020; 11:1254. [PMID: 32198392 PMCID: PMC7083845 DOI: 10.1038/s41467-020-14992-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 02/11/2020] [Indexed: 12/20/2022] Open
Abstract
Chlorophyll is indispensable for life on Earth. Dynamic control of chlorophyll level, determined by the relative rates of chlorophyll anabolism and catabolism, ensures optimal photosynthesis and plant fitness. How plants post-translationally coordinate these two antagonistic pathways during their lifespan remains enigmatic. Here, we show that two Arabidopsis paralogs of BALANCE of CHLOROPHYLL METABOLISM (BCM) act as functionally conserved scaffold proteins to regulate the trade-off between chlorophyll synthesis and breakdown. During early leaf development, BCM1 interacts with GENOMES UNCOUPLED 4 to stimulate Mg-chelatase activity, thus optimizing chlorophyll synthesis. Meanwhile, BCM1’s interaction with Mg-dechelatase promotes degradation of the latter, thereby preventing chlorophyll degradation. At the onset of leaf senescence, BCM2 is up-regulated relative to BCM1, and plays a conserved role in attenuating chlorophyll degradation. These results support a model in which post-translational regulators promote chlorophyll homeostasis by adjusting the balance between chlorophyll biosynthesis and breakdown during leaf development. Plants regulate chlorophyll levels to optimise photosynthesis. Here Wang et al. describe two paralogous thylakoid proteins, BCM1 and BCM2, which stimulate chlorophyll biosynthesis and attenuate chlorophyll degradation respectively through interaction with the Mg-chelatase-stimulating factor GUN4 and Mg-dechelatase isoform SGR1.
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Affiliation(s)
- Peng Wang
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13, 10115, Berlin, Germany.
| | - Andreas S Richter
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13, 10115, Berlin, Germany.,Institute of Biology/Physiology of Plant Cell Organelles, Humboldt-Universität zu Berlin, Philippstraße 13, 10115, Berlin, Germany
| | - Julius R W Kleeberg
- Zellbiologie/Elektronenmikroskopie, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Stefan Geimer
- Zellbiologie/Elektronenmikroskopie, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13, 10115, Berlin, Germany.
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14
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Schmied J, Hou Z, Hedtke B, Grimm B. Controlled Partitioning of Glutamyl-tRNA Reductase in Stroma- and Membrane-Associated Fractions Affects the Synthesis of 5-Aminolevulinic Acid. PLANT & CELL PHYSIOLOGY 2018; 59:2204-2213. [PMID: 30032295 DOI: 10.1093/pcp/pcy143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/13/2018] [Indexed: 06/08/2023]
Abstract
The synthesis of 5-aminolevulinic acid (ALA) determines adequate amounts of metabolites for the tetrapyrrole biosynthetic pathway. Glutamyl-tRNA reductase (GluTR) catalyzes the rate-limiting step of ALA synthesis and was previously considered to be exclusively localized in the chloroplast stroma of light-exposed plants. To assess the intraplastidic localization of GluTR, we developed a fast separation protocol of soluble and membrane-bound proteins and reassessed the subplastidal allocation of GluTR in stroma and membrane fractions of Arabidopsis plants grown under different light regimes as well as during de-etiolation and dark incubations. Under the examined conditions, the amount of stroma-localized GluTR correlated with the ALA synthesis rate. The transfer to dark repression of ALA synthesis resulted in a loss of soluble GluTR. Arabidopsis mutants lacking one of the GluTR-interacting factors FLUORESCENT (FLU), the GluTR-binding protein (GBP) or ClpC, a chaperone of the Clp protease system, were applied to examine the amount of GluTR and its distribution to the stroma or membrane in darkness and light. Taking into consideration the different compartmental allocation of GluTR, its stability and ALA synthesis rates, the post-translational impact of these regulatory factors on GluTR activity and plastidic sublocalization is discussed.
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Affiliation(s)
- Judith Schmied
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
| | - Zhiwei Hou
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
| | - Boris Hedtke
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
| | - Bernhard Grimm
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
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15
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Park JH, Tran LH, Jung S. Perturbations in the Photosynthetic Pigment Status Result in Photooxidation-Induced Crosstalk between Carotenoid and Porphyrin Biosynthetic Pathways. FRONTIERS IN PLANT SCIENCE 2017; 8:1992. [PMID: 29209351 PMCID: PMC5701815 DOI: 10.3389/fpls.2017.01992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 11/06/2017] [Indexed: 06/01/2023]
Abstract
Possible crosstalk between the carotenoid and porphyrin biosynthetic pathways under photooxidative conditions was investigated by using their biosynthetic inhibitors, norflurazon (NF) and oxyfluorfen (OF). High levels of protoporphyrin IX (Proto IX) accumulated in rice plants treated with OF, whereas Proto IX decreased in plants treated with NF. Both NF and OF treatments resulted in greater decreases in MgProto IX, MgProto IX methyl ester, and protochlorophyllide. Activities and transcript levels of most porphyrin biosynthetic enzymes, particularly in the Mg-porphyrin branch, were greatly down-regulated in NF and OF plants. In contrast, the transcript levels of GSA, PPO1, and CHLD as well as FC2 and HO2 were up-regulated in NF-treated plants, while only moderate increases in FC2 and HO2 were observed in the early stage of OF treatment. Phytoene, antheraxanthin, and zeaxanthin showed high accumulation in NF-treated plants, whereas other carotenoid intermediates greatly decreased. Transcript levels of carotenoid biosynthetic genes, PSY1 and PDS, decreased in response to NF and OF, whereas plants in the later stage of NF treatment exhibited up-regulation of BCH and VDE as well as recovery of PDS. However, perturbed porphyrin biosynthesis by OF did not noticeably influence levels of carotenoid metabolites, regardless of the strong down-regulation of carotenoid biosynthetic genes. Both NF and OF plants appeared to provide enhanced protection against photooxidative damage, not only by scavenging of Mg-porphyrins, but also by up-regulating FC2, HO2, and Fe-chelatase, particularly with increased levels of zeaxanthin via up-regulation of BCH and VDE in NF plants. On the other hand, the up-regulation of GSA, PPO1, and CHLD under inhibition of carotenogenic flux may be derived from the necessity to recover impaired chloroplast biogenesis during photooxidative stress. Our study demonstrates that perturbations in carotenoid and porphyrin biosynthesis coordinate the expression of their biosynthetic genes to sustain plastid function at optimal levels by regulating their metabolic flux in plants under adverse stress conditions.
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Affiliation(s)
| | | | - Sunyo Jung
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences and Biotechnology, Kyungpook National University, Daegu, South Korea
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16
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Park JH, Jung S. Perturbations of carotenoid and tetrapyrrole biosynthetic pathways result in differential alterations in chloroplast function and plastid signaling. Biochem Biophys Res Commun 2017; 482:672-677. [PMID: 27865844 DOI: 10.1016/j.bbrc.2016.11.092] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 11/30/2022]
Abstract
In this study, we used the biosynthetic inhibitors of carotenoid and tetrapyrrole biosynthetic pathways, norflurazon (NF) and oxyfluorfen (OF), as tools to gain insight into mechanisms of photooxidation in rice plants. NF resulted in bleaching symptom on leaves of the treated plants, whereas OF treatment developed a fast symptom of an apparent necrotic phenotype. Both plants exhibited decreases in photosynthetic efficiency, as indicated by Fv/Fm. NF caused severe disruption in thylakoid membranes, whereas OF-treated plants exhibited disruption of chloroplast envelope and plasma membrane. Levels of Lhca and Lhcb proteins in photosystem I (PSI) and PSII were reduced by photooxidative stress in NF- and OF-treated plants, with a greater decrease in NF plants. The down-regulation of nuclear-encoded photosynthesis genes Lhcb and rbcS was also found in both NF- and OF-treated plants, whereas plastid-encoded photosynthetic genes including RbcL, PsaC, and PsbD accumulated normally in NF plants but decreased drastically in OF plants. This proposes that the plastids in NF plants retain their potential to develop thylakoid membranes and that photobleaching is mainly controlled by nuclear genes. Distinct photooxidation patterns between NF- and OF-treated plants developed differential signaling, which might enable the plant to coordinate the expression of photosynthetic genes from the nuclear and plastidic genomes.
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Affiliation(s)
- Joon-Heum Park
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, South Korea
| | - Sunyo Jung
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, South Korea.
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17
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Li X, Kanakala S, He Y, Zhong X, Yu S, Li R, Sun L, Ma J. Physiological Characterization and Comparative Transcriptome Analysis of White and Green Leaves of Ananas comosus var. bracteatus. PLoS One 2017; 12:e0169838. [PMID: 28095462 PMCID: PMC5240938 DOI: 10.1371/journal.pone.0169838] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/22/2016] [Indexed: 11/18/2022] Open
Abstract
Leaf coloration is one of the most important and attractive characteristics of Ananas comosus var. bracteatus. The chimeric character is not stable during the in vitro tissue culturing. Many regenerated plants lost economic values for the loss of the chimeric character of leaves. In order to reveal the molecular mechanisms involved in the albino phenotype of the leaf cells, the physiological and transcriptional differences between complete white (CWh) and green (CGr) leaf cells of A. comosus var. bracteatus were analyzed. A total of 1,431 differentially expressed unigenes (DEGs) in CGr and CWh leaves were identified using RNA-seq. A comparison to the COG, GO and KEGG annotations revealed DEGs involved in chlorophyll biosynthesis, chloroplast development and photosynthesis. Furthermore, the measurement of main precursors of chlorophyll in the CWh leaves confirmed that the rate-limiting step in chlorophyll biosynthesis, and thus the cause of the albino phenotype of the white cells, was the conversion of pyrrole porphobilinogen (PBG) to uroporphyrinogen III (Uro III). The enzyme activity of porphobilinogen deaminase (PBGD) and uroporporphyrinogn III synthase (UROS), which catalyze the transition of PBG to Uro III, was significantly decreased in the CWh leaves. Our data showed the transcriptional differences between the CWh and CGr plants and characterized key steps in chlorophyll biosynthesis of the CWh leaves. These results contribute to our understanding of the mechanisms and regulation of pigment biosynthesis in the CWh leaf cells of A. comosus var. bracteatus.
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Affiliation(s)
- Xia Li
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Surapathrudu Kanakala
- Institute of Plant Protection, Agricultural Research Organization, The Volcani Center, Beit Dagan, Israel
| | - Yehua He
- Horticultural Biotechnology College of South China Agricultural University, Guangzhou, Guangdong, China
| | - Xiaolan Zhong
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Sanmiao Yu
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Ruixue Li
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Lingxia Sun
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Jun Ma
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
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18
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Hey D, Ortega-Rodes P, Fan T, Schnurrer F, Brings L, Hedtke B, Grimm B. Transgenic Tobacco Lines Expressing Sense or Antisense FERROCHELATASE 1 RNA Show Modified Ferrochelatase Activity in Roots and Provide Experimental Evidence for Dual Localization of Ferrochelatase 1. PLANT & CELL PHYSIOLOGY 2016; 57:2576-2585. [PMID: 27818378 DOI: 10.1093/pcp/pcw171] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 10/03/2016] [Indexed: 06/06/2023]
Abstract
In plants, two genes encode ferrochelatase (FC), which catalyzes iron chelation into protoporphyrin IX at the final step of heme biosynthesis. FERROCHELATASE1 (FC1) is continuously, but weakly expressed in roots and leaves, while FC2 is dominantly active in leaves. As a continuation of previous studies on the physiological consequences of FC2 inactivation in tobacco, we aimed to assign FC1 function in plant organs. While reduced FC2 expression leads to protoporphyrin IX accumulation in leaves, FC1 down-regulation and overproduction caused reduced and elevated FC activity in root tissue, respectively, but were not associated with changes in macroscopic phenotype, plant development or leaf pigmentation. In contrast to the lower heme content resulting from a deficiency of the dominant FC2 expression in leaves, a reduction of FC1 in roots and leaves does not significantly disturb heme accumulation. The FC1 overexpression was used for an additional approach to re-examine FC activity in mitochondria. Transgenic FC1 protein was immunologically shown to be present in mitochondria. Although matching only a small portion of total cellular FC activity, the mitochondrial FC activity in a FC1 overexpressor line increased 5-fold in comparison with wild-type mitochondria. Thus, it is suggested that FC1 contributes to mitochondrial heme synthesis.
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Affiliation(s)
- Daniel Hey
- Humboldt-University Berlin, Institute of Biology/Plant Physiology, Philippstr.13, Building 12, D-10115 Berlin, Germany
| | - Patricia Ortega-Rodes
- Humboldt-University Berlin, Institute of Biology/Plant Physiology, Philippstr.13, Building 12, D-10115 Berlin, Germany
| | - Tingting Fan
- Humboldt-University Berlin, Institute of Biology/Plant Physiology, Philippstr.13, Building 12, D-10115 Berlin, Germany
| | - Florian Schnurrer
- Humboldt-University Berlin, Institute of Biology/Plant Physiology, Philippstr.13, Building 12, D-10115 Berlin, Germany
| | - Lea Brings
- Humboldt-University Berlin, Institute of Biology/Plant Physiology, Philippstr.13, Building 12, D-10115 Berlin, Germany
| | - Boris Hedtke
- Humboldt-University Berlin, Institute of Biology/Plant Physiology, Philippstr.13, Building 12, D-10115 Berlin, Germany
| | - Bernhard Grimm
- Humboldt-University Berlin, Institute of Biology/Plant Physiology, Philippstr.13, Building 12, D-10115 Berlin, Germany
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19
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Brzezowski P, Sharifi MN, Dent RM, Morhard MK, Niyogi KK, Grimm B. Mg chelatase in chlorophyll synthesis and retrograde signaling in Chlamydomonas reinhardtii: CHLI2 cannot substitute for CHLI1. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3925-38. [PMID: 26809558 PMCID: PMC4915523 DOI: 10.1093/jxb/erw004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The oligomeric Mg chelatase (MgCh), consisting of the subunits CHLH, CHLI, and CHLD, is located at the central site of chlorophyll synthesis, but is also thought to have an additional function in regulatory feedback control of the tetrapyrrole biosynthesis pathway and in chloroplast retrograde signaling. In Arabidopsis thaliana and Chlamydomonas reinhardtii, two genes have been proposed to encode the CHLI subunit of MgCh. While the role of CHLI1 in A. thaliana MgCh has been substantially elucidated, different reports provide inconsistent results with regard to the function of CHLI2 in Mg chelation and retrograde signaling. In the present report, the possible functions of both isoforms were analyzed in C. reinhardtii Knockout of the CHLI1 gene resulted in complete loss of MgCh activity, absence of chlorophyll, acute light sensitivity, and, as a consequence, down-regulation of tetrapyrrole biosynthesis and photosynthesis-associated nuclear genes. These observations indicate a phenotypical resemblance of chli1 to the chlh and chld C. reinhardtii mutants previously reported. The key role of CHLI1 for MgCh reaction in comparison with the second isoform was confirmed by the rescue of chli1 with genomic CHLI1 Because CHLI2 in C. reinhardtii shows lower expression than CHLI1, strains overexpressing CHLI2 were produced in the chli1 background. However, no complementation of the chli1 phenotype was observed. Silencing of CHLI2 in the wild-type background did not result in any changes in the accumulation of tetrapyrrole intermediates or of chlorophyll. The results suggest that, unlike in A. thaliana, changes in CHLI2 content observed in the present studies do not affect formation and activity of MgCh in C. reinhardtii.
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Affiliation(s)
- Pawel Brzezowski
- Institute of Biology/Plant Physiology, Humboldt University, Philippstraße 13, D-10115 Berlin, Germany
| | - Marina N Sharifi
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3102, USA Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Rachel M Dent
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3102, USA Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Marius K Morhard
- Institute of Biology/Plant Physiology, Humboldt University, Philippstraße 13, D-10115 Berlin, Germany
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3102, USA Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt University, Philippstraße 13, D-10115 Berlin, Germany
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20
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Woodson JD, Joens MS, Sinson AB, Gilkerson J, Salomé PA, Weigel D, Fitzpatrick JA, Chory J. Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts. Science 2015; 350:450-4. [PMID: 26494759 PMCID: PMC4863637 DOI: 10.1126/science.aac7444] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/18/2015] [Indexed: 12/17/2022]
Abstract
Energy production by chloroplasts and mitochondria causes constant oxidative damage. A functioning photosynthetic cell requires quality-control mechanisms to turn over and degrade chloroplasts damaged by reactive oxygen species (ROS). Here, we generated a conditionally lethal Arabidopsis mutant that accumulated excess protoporphyrin IX in the chloroplast and produced singlet oxygen. Damaged chloroplasts were subsequently ubiquitinated and selectively degraded. A genetic screen identified the plant U-box 4 (PUB4) E3 ubiquitin ligase as being necessary for this process. pub4-6 mutants had defects in stress adaptation and longevity. Thus, we have identified a signal that leads to the targeted removal of ROS-overproducing chloroplasts.
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Affiliation(s)
| | - Matthew S Joens
- Waitt Advanced Biophotonics Center, The Salk Institute, La Jolla, CA
| | - Andrew B Sinson
- Plant Biology Laboratory, The Salk Institute, La Jolla, CA. Division of Biological Sciences, University of California-San Diego, La Jolla, CA
| | - Jonathan Gilkerson
- Plant Biology Laboratory, The Salk Institute, La Jolla, CA. Howard Hughes Medical Institute, The Salk Institute, La Jolla, CA
| | - Patrice A Salomé
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | | | - Joanne Chory
- Plant Biology Laboratory, The Salk Institute, La Jolla, CA. Howard Hughes Medical Institute, The Salk Institute, La Jolla, CA.
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21
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Trösch R, Töpel M, Flores-Pérez Ú, Jarvis P. Genetic and Physical Interaction Studies Reveal Functional Similarities between ALBINO3 and ALBINO4 in Arabidopsis. PLANT PHYSIOLOGY 2015; 169:1292-306. [PMID: 26265777 PMCID: PMC4587442 DOI: 10.1104/pp.15.00376] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 08/06/2015] [Indexed: 05/20/2023]
Abstract
ALBINO3 (ALB3) is a well-known component of a thylakoid protein-targeting complex that interacts with the chloroplast signal recognition particle (cpSRP) and the cpSRP receptor, chloroplast filamentous temperature-sensitive Y (cpFtsY). Its protein-inserting function has been established mainly for light-harvesting complex proteins, which first interact with the unique chloroplast cpSRP43 component and then are delivered to the ALB3 integrase by a GTP-dependent cpSRP-cpFtsY interaction. In Arabidopsis (Arabidopsis thaliana), a subsequently discovered ALB3 homolog, ALB4, has been proposed to be involved not in light-harvesting complex protein targeting, but instead in the stabilization of the ATP synthase complex. Here, however, we show that ALB3 and ALB4 share significant functional overlap, and that both proteins are required for the efficient insertion of cytochrome f and potentially other subunits of pigment-bearing protein complexes. Genetic and physical interactions between ALB4 and ALB3, and physical interactions between ALB4 and cpSRP, suggest that the two ALB proteins may engage similar sets of interactors for their specific functions. We propose that ALB4 optimizes the insertion of thylakoid proteins by participating in the ALB3-cpSRP pathway for certain substrates (e.g. cytochrome f and the Rieske protein). Although ALB4 has clearly diverged from ALB3 in relation to the partner-recruiting C-terminal domain, our analysis suggests that one putative cpSRP-binding motif has not been entirely lost.
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Affiliation(s)
- Raphael Trösch
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom (R.T., M.T., P.J.); andDepartment of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom (U.F.-P., P.J.)
| | - Mats Töpel
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom (R.T., M.T., P.J.); andDepartment of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom (U.F.-P., P.J.)
| | - Úrsula Flores-Pérez
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom (R.T., M.T., P.J.); andDepartment of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom (U.F.-P., P.J.)
| | - Paul Jarvis
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom (R.T., M.T., P.J.); andDepartment of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom (U.F.-P., P.J.)
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Function of Tetrapyrroles, Regulation of Tetrapyrrole Metabolism and Methods for Analyses of Tetrapyrroles. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.proche.2015.03.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Brzezowski P, Schlicke H, Richter A, Dent RM, Niyogi KK, Grimm B. The GUN4 protein plays a regulatory role in tetrapyrrole biosynthesis and chloroplast-to-nucleus signalling in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:285-98. [PMID: 24861705 DOI: 10.1111/tpj.12560] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/02/2014] [Accepted: 05/09/2014] [Indexed: 05/08/2023]
Abstract
The GENOMES UNCOUPLED 4 (GUN4) protein is found only in aerobic photosynthetic organisms. We investigated the role of GUN4 in metabolic activities of the Mg branch of the tetrapyrrole biosynthesis pathway and the plastid signal-mediated changes of nuclear gene expression in Chlamydomonas reinhardtii. In light, gun4 accumulates only 40% of the wild-type chlorophyll level. Light- or dark-grown gun4 mutant accumulates high levels of protoporphyrin IX (Proto), and displays increased sensitivity to moderate light intensities. Despite the photooxidative stress, gun4 fails to downregulate mRNA levels of the tetrapyrrole biosynthesis and the photosynthesis-associated nuclear genes (PhANGs). In contrast, upon illumination, the Proto-accumulating and light-sensitive chlD-1 mutant displays the expected downregulation of the same nuclear genes. Although chlD-1 and the wild type have similar GUN4 transcript levels, the GUN4 protein in chlD-1 is hardly detectable. Overexpression of GUN4 in chlD-1 modifies the downregulation of nuclear gene expression, but also increases light tolerance. Therefore, GUN4 is proposed to function in 'shielding' Proto, and most likely MgProto, by reducing reactivity with O2 . Furthermore, GUN4 seems to be involved in sensing elevated levels of these photoreactive tetrapyrrole intermediates, and contributing to (1) O2 -mediated retrograde signalling, originating from chlorophyll biosynthesis.
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Affiliation(s)
- Pawel Brzezowski
- Institute of Biology/Plant Physiology, Humboldt University, Philippstraße 13, 10115, Berlin, Germany
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Apitz J, Schmied J, Lehmann MJ, Hedtke B, Grimm B. GluTR2 Complements a hema1 Mutant Lacking Glutamyl-tRNA Reductase 1, but is Differently Regulated at the Post-Translational Level. ACTA ACUST UNITED AC 2014; 55:645-57. [DOI: 10.1093/pcp/pcu016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Tetrapyrrole biosynthetic enzyme protoporphyrinogen IX oxidase 1 is required for plastid RNA editing. Proc Natl Acad Sci U S A 2014; 111:2023-8. [PMID: 24497494 DOI: 10.1073/pnas.1316183111] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RNA editing is a posttranscriptional process that covalently alters the sequence of RNA molecules and plays important biological roles in both animals and land plants. In flowering plants, RNA editing converts specific cytidine residues to uridine in both plastid and mitochondrial transcripts. Previous studies identified pentatricopeptide repeat (PPR) motif-containing proteins as site-specific recognition factors for cytidine targets in RNA sequences. However, the regulatory mechanism underlying RNA editing was largely unknown. Here, we report that protoporphyrinogen IX oxidase 1 (PPO1), an enzyme that catalyzes protoporphyrinogen IX into protoporphyrin IX in the tetrapyrrole biosynthetic pathway, plays an unexpected role in editing multiple sites of plastid RNA transcripts, most of which encode subunits of the NADH dehydrogenase-like complex (NDH), in the reference plant Arabidopsis thaliana. We identified multiple organellar RNA editing factors (MORFs), including MORF2, MORF8, and MORF9, that interact with PPO1. We found that two conserved motifs within the 22-aa region at the N terminus of PPO1 are essential for its interaction with MORFs, its RNA editing function, and subsequently, its effect on NDH activity. However, transgenic plants lacking key domains for the tetrapyrrole biosynthetic activity of PPO1 exhibit normal RNA editing. Furthermore, MORF2 and MORF9 interact with three PPRs or related proteins required for editing of ndhB and ndhD sites. These results reveal that the tetrapyrrole biosynthetic enzyme PPO1 is required for plastid RNA editing, acting as a regulator that promotes the stability of MORF proteins through physical interaction.
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Luo T, Luo S, Araújo WL, Schlicke H, Rothbart M, Yu J, Fan T, Fernie AR, Grimm B, Luo M. Virus-induced gene silencing of pea CHLI and CHLD affects tetrapyrrole biosynthesis, chloroplast development and the primary metabolic network. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 65:17-26. [PMID: 23416492 DOI: 10.1016/j.plaphy.2013.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 01/04/2013] [Indexed: 05/04/2023]
Abstract
The first committed and highly regulated step of chlorophyll biosynthesis is the insertion of Mg(2+) into protoporphyrin IX, which is catalyzed by Mg chelatase that consists of CHLH, CHLD and CHLI subunits. In this study, CHLI and CHLD genes were suppressed by virus-induced gene silencing (VIGS-CHLI and VIGS-CHLD) in pea (Pisum sativum), respectively. VIGS-CHLI and VIGS-CHLD plants both showed yellow leaf phenotypes with the reduced Mg chelatase activity and the inactivated synthesis of 5-aminolevulinic acid. The lower chlorophyll accumulation correlated with undeveloped thylakoid membranes, altered chloroplast nucleoid structure, malformed antenna complexes and compromised photosynthesis capacity in the yellow leaf tissues of the VIGS-CHLI and VIGS-CHLD plants. Non-enzymatic antioxidant contents and the activities of antioxidant enzymes were altered in response to enhanced accumulation of reactive oxygen species (ROS) in the chlorophyll deficient leaves of VIGS-CHLI and VIGS-CHLD plants. Furthermore, the results of metabolite profiling indicate a tight correlation between primary metabolic pathways and Mg chelatase activity. We also found that CHLD induces a feedback-regulated change of the transcription of photosynthesis-associated nuclear genes. CHLD and CHLI silencing resulted in a rapid reduction of photosynthetic proteins. Taken together, Mg chelatase is not only a key regulator of tetrapyrrole biosynthesis but its activity also correlates with ROS homeostasis, primary interorganellar metabolism and retrograde signaling in plant cells.
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Affiliation(s)
- Tao Luo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, PR China
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