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Huque AKMM, So W, Noh M, You MK, Shin JS. Overexpression of AtBBD1, Arabidopsis Bifunctional Nuclease, Confers Drought Tolerance by Enhancing the Expression of Regulatory Genes in ABA-Mediated Drought Stress Signaling. Int J Mol Sci 2021; 22:ijms22062936. [PMID: 33805821 PMCID: PMC8001636 DOI: 10.3390/ijms22062936] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/03/2021] [Accepted: 03/10/2021] [Indexed: 11/16/2022] Open
Abstract
Drought is the most serious abiotic stress, which significantly reduces crop productivity. The phytohormone ABA plays a pivotal role in regulating stomatal closing upon drought stress. Here, we characterized the physiological function of AtBBD1, which has bifunctional nuclease activity, on drought stress. We found that AtBBD1 localized to the nucleus and cytoplasm, and was expressed strongly in trichomes and stomatal guard cells of leaves, based on promoter:GUS constructs. Expression analyses revealed that AtBBD1 and AtBBD2 are induced early and strongly by ABA and drought, and that AtBBD1 is also strongly responsive to JA. We then compared phenotypes of two AtBBD1-overexpression lines (AtBBD1-OX), single knockout atbbd1, and double knockout atbbd1/atbbd2 plants under drought conditions. We did not observe any phenotypic difference among them under normal growth conditions, while OX lines had greatly enhanced drought tolerance, lower transpirational water loss, and higher proline content than the WT and KOs. Moreover, by measuring seed germination rate and the stomatal aperture after ABA treatment, we found that AtBBD1-OX and atbbd1 plants showed significantly higher and lower ABA-sensitivity, respectively, than the WT. RNA sequencing analysis of AtBBD1-OX and atbbd1 plants under PEG-induced drought stress showed that overexpression of AtBBD1 enhances the expression of key regulatory genes in the ABA-mediated drought signaling cascade, particularly by inducing genes related to ABA biosynthesis, downstream transcription factors, and other regulatory proteins, conferring AtBBD1-OXs with drought tolerance. Taken together, we suggest that AtBBD1 functions as a novel positive regulator of drought responses by enhancing the expression of ABA- and drought stress-responsive genes as well as by increasing proline content.
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Affiliation(s)
- A. K. M. Mahmudul Huque
- Division of Life Sciences, Korea University, Seoul 02841, Korea; (A.K.M.M.H.); (W.S.); (M.N.)
| | - Wonmi So
- Division of Life Sciences, Korea University, Seoul 02841, Korea; (A.K.M.M.H.); (W.S.); (M.N.)
| | - Minsoo Noh
- Division of Life Sciences, Korea University, Seoul 02841, Korea; (A.K.M.M.H.); (W.S.); (M.N.)
| | - Min Kyoung You
- Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea
- Correspondence: (M.K.Y.); (J.S.S.)
| | - Jeong Sheop Shin
- Division of Life Sciences, Korea University, Seoul 02841, Korea; (A.K.M.M.H.); (W.S.); (M.N.)
- Correspondence: (M.K.Y.); (J.S.S.)
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2
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Sun Y, Liang W, Cheng H, Wang H, Lv D, Wang W, Liang M, Miao C. NADPH Oxidase-derived ROS promote mitochondrial alkalization under salt stress in Arabidopsis root cells. Plant Signal Behav 2021; 16:1856546. [PMID: 33315520 PMCID: PMC7889232 DOI: 10.1080/15592324.2020.1856546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
The plasma membrane NADPH Oxidase-derived ROS as signaling molecules play crucial roles in salt stress response. As the motor organelle of cells, mitochondria are also important for salt tolerance. However, the possible interaction between NADPH Oxidase-derived ROS and mitochondria is not well studied. Here, a transgenic Arabidopsis expressing mitochondrial matrix-targeted pH-sensitive indicator cpYFP was used to monitor the pH dynamics in root cells under salt stress. A significant alkalization in mitochondria was observed when the root was exposed to NaCl or KCl, but not osmotic stress such as isotonic mannitol. Interestingly, when pretreated with the NADPH Oxidase inhibitor DPI, the mitochondrial alkalization in root cells was largely abolished. Genetic evidence further showed that salt-induced mitochondrial alkalization was significantly reduced in the loss of function mutant atrbohF . Pretreatment with endocytosis-related inhibitor PAO or TyrA23, which inhibited the ROS accumulation under salt treatment, almost abolished this effect. Furthermore, [Ca2+]cyt increase might also play important roles by affecting ROS generation to mediate salt-induced mitochondrial alkalization as indicated by treatment with plasma membrane Ca2+ channel inhibitor LaCl3 and mitochondrial Ca2+ uniporter inhibitor Ruthenium Red. Together, these results suggest that the plasma membrane NADPH Oxidase-derived ROS promote the mitochondrial alkalization under salt treatment, providing a possible link between different cellular compartments under salt stress.
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Affiliation(s)
- Yanfeng Sun
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Weihong Liang
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Hui Cheng
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Huan Wang
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Dong Lv
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Wei Wang
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Modan Liang
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Chen Miao
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China
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Chu M, Chen P, Meng S, Xu P, Lan W. The Arabidopsis phosphatase PP2C49 negatively regulates salt tolerance through inhibition of AtHKT1;1. J Integr Plant Biol 2021; 63:528-542. [PMID: 32877013 DOI: 10.1111/jipb.13008] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/31/2020] [Indexed: 05/08/2023]
Abstract
Type 2C protein phosphatases (PP2Cs) are the largest protein phosphatase family. PP2Cs dephosphorylate substrates for signaling in Arabidopsis, but the functions of most PP2Cs remain unknown. Here, we characterized PP2C49 (AT3G62260, a Group G PP2C), which regulates Na+ distribution under salt stress and is localized to the cytoplasm and nucleus. PP2C49 was highly expressed in root vascular tissues and its disruption enhanced plant tolerance to salt stress. Compared with wild type, the pp2c49 mutant contained more Na+ in roots but less Na+ in shoots and xylem sap, suggesting that PP2C49 regulates shoot Na+ extrusion. Reciprocal grafting revealed a root-based mechanism underlying the salt tolerance of pp2c49. Systemic Na+ distribution largely depends on AtHKT1;1 and loss of function of AtHKT1;1 in the pp2c49 background overrode the salt tolerance of pp2c49, resulting in salt sensitivity. Furthermore, compared with plants overexpressing PP2C49 in the wild-type background, plants overexpressing PP2C49 in the athtk1;1 mutant background were sensitive to salt, like the athtk1;1 mutants. Moreover, protein-protein interaction and two-voltage clamping assays demonstrated that PP2C49 physically interacts with AtHKT1;1 and inhibits the Na+ permeability of AtHKT1;1. This study reveals that PP2C49 negatively regulates AtHKT1;1 activity and thus determines systemic Na+ allocation during salt stress.
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Affiliation(s)
- Moli Chu
- State Key Laboratory for Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Pengwang Chen
- State Key Laboratory for Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Sufang Meng
- State Key Laboratory for Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Peng Xu
- State Key Laboratory for Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Wenzhi Lan
- State Key Laboratory for Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
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4
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Che C, Zeng Y, Xu Y, Lu H, Xu Y, Zhang X, Xiao Y, Li JQ, Qin Z. APA n, a Class of ABA Receptor Agonism/Antagonism Switching Probes. J Agric Food Chem 2020; 68:8524-8534. [PMID: 32687337 DOI: 10.1021/acs.jafc.0c02154] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In plants, biosynthesized ABA undergoes two important physiological processes of signal transduction and metabolism simultaneously. In this study, we described a class of ABA receptor agonist/antagonist switching probes APAn, which can regulate the agonistic activity or antagonistic activity according to the length of a 6'-alkoxyl chain. From APA1 to APA6, with the extension of the alkoxyl chain, it showed a gradually increased receptor-binding potential and decreased HAB1 inhibition activity. Theoretical analysis based on molecular docking and molecular dynamics simulation revealed that some factors outside the ligand-binding pocket in receptors could also affect the binding of the ligand to the receptor, for example, the van der Waals interaction between the alkyl chain in APAn and the 3'-tunnel of ABA receptors made it bind more tightly than iso-PhABA. This enhanced binding made it an antagonist rather than a weakened agonist.
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5
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Bian C, Guo X, Zhang Y, Wang L, Xu T, DeLong A, Dong J. Protein phosphatase 2A promotes stomatal development by stabilizing SPEECHLESS in Arabidopsis. Proc Natl Acad Sci U S A 2020; 117:13127-13137. [PMID: 32434921 PMCID: PMC7293623 DOI: 10.1073/pnas.1912075117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Stomatal guard cells control gas exchange that allows plant photosynthesis but limits water loss from plants to the environment. In Arabidopsis, stomatal development is mainly controlled by a signaling pathway comprising peptide ligands, membrane receptors, a mitogen-activated protein kinase (MAPK) cascade, and a set of transcription factors. The initiation of the stomatal lineage requires the activity of the bHLH transcription factor SPEECHLESS (SPCH) with its partners. Multiple kinases were found to regulate SPCH protein stability and function through phosphorylation, yet no antagonistic protein phosphatase activities have been identified. Here, we identify the conserved PP2A phosphatases as positive regulators of Arabidopsis stomatal development. We show that mutations in genes encoding PP2A subunits result in lowered stomatal production in Arabidopsis Genetic analyses place the PP2A function upstream of SPCH. Pharmacological treatments support a role for PP2A in promoting SPCH protein stability. We further find that SPCH directly binds to the PP2A-A subunits in vitro. In plants, nonphosphorylatable SPCH proteins are less affected by PP2A activity levels. Thus, our research suggests that PP2A may function to regulate the phosphorylation status of the master transcription factor SPCH in stomatal development.
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Affiliation(s)
- Chao Bian
- The Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901
| | - Xiaoyu Guo
- The Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
| | - Yi Zhang
- The Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
- Fujian Agriculture and Forestry University-Joint Centre, Horticulture and Metabolic Biology Centre, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002 Fuzhou, People's Republic of China
| | - Lu Wang
- The Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901
| | - Tongda Xu
- Fujian Agriculture and Forestry University-Joint Centre, Horticulture and Metabolic Biology Centre, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002 Fuzhou, People's Republic of China
| | - Alison DeLong
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912
| | - Juan Dong
- The Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854;
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901
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6
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Graña E, Díaz-Tielas C, Sánchez-Moreiras AM, Reigosa MJ, Celeiro M, Abagyan R, Teijeira M, Duke MV, Clerk T, Pan Z, Duke SO. Transcriptome and binding data indicate that citral inhibits single strand DNA-binding proteins. Physiol Plant 2020; 169:99-109. [PMID: 31828797 DOI: 10.1111/ppl.13055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
The mechanism of phytotoxicity of citral was probed in Arabidopsis thaliana using RNA-Seq and in silico binding analyses. Inhibition of growth by 50% by citral downregulated transcription of 9156 and 5541 genes in roots and shoots, respectively, after 1 h. Only 56 and 62 genes in roots and shoots, respectively, were upregulated. In the shoots, the downregulation increased at 3 h (6239 genes downregulated, vs 66 upregulated). Of all genes affected in roots at 1 h (time of greatest effect), 7.69% of affected genes were for nucleic acid binding functions. Genes for single strand DNA binding proteins (SSBP) WHY1, WHY 2 and WHY3 were strongly downregulated in the shoot up until 12 h after citral exposure. Effects were strong in the root at just 1 h after the treatment and then at 12 and 24 h. Similar effects occurred with the transcription factors MYC-2, ANAC and SCR-SHR, which were also significantly downregulated for the first hour of treatment, and downregulation occurred again after 12 and 24 h treatment. Downregulation of ANAC in the first hour of treatment was significantly (P < 0.0001) decreased more than eight times compared to the control. In silico molecular docking analysis suggests binding of citral isomers to the SSBPs WHY1, WHY2, and WHY3, as well as with other transcription factors such as MYC-2, ANAC and SCR-SHR. Such effects could account for the profound and unusual effects of citral on downregulation of gene transcription.
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Affiliation(s)
- Elisa Graña
- Department of Plant Biology and Soil Science, University of Vigo, Vigo, 36310, Spain
| | - Carla Díaz-Tielas
- Department of Plant Biology and Soil Science, University of Vigo, Vigo, 36310, Spain
| | - Adela M Sánchez-Moreiras
- Department of Plant Biology and Soil Science, University of Vigo, Vigo, 36310, Spain
- Agri-Food Research and Transfer Centre of the Water Campus (CITACA), University of Vigo, Vigo, Spain
| | - Manuel J Reigosa
- Department of Plant Biology and Soil Science, University of Vigo, Vigo, 36310, Spain
- Agri-Food Research and Transfer Centre of the Water Campus (CITACA), University of Vigo, Vigo, Spain
| | - María Celeiro
- Department of Organic Chemistry, University of Vigo, Vigo, 36310, Spain
- Institute of Health of Southern Galicia, University of Vigo, Vigo, 36310, Spain
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Ruben Abagyan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Marta Teijeira
- Department of Organic Chemistry, University of Vigo, Vigo, 36310, Spain
- Institute of Health of Southern Galicia, University of Vigo, Vigo, 36310, Spain
| | - Mary V Duke
- USDA, ARS, Genomics and Bioinformatics Research Unit, Stoneville, MS, 38776, USA
| | - Tracy Clerk
- USDA, ARS, Genomics and Bioinformatics Research Unit, Stoneville, MS, 38776, USA
| | - Zhiqiang Pan
- USDA, ARS, Natural Products Utilization Research Unit, Oxford, MS, 38677, USA
| | - Stephen O Duke
- USDA, ARS, Natural Products Utilization Research Unit, Oxford, MS, 38677, USA
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7
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Lv M, Li J. Molecular Mechanisms of Brassinosteroid-Mediated Responses to Changing Environments in Arabidopsis. Int J Mol Sci 2020; 21:ijms21082737. [PMID: 32326491 PMCID: PMC7215551 DOI: 10.3390/ijms21082737] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 04/06/2020] [Accepted: 04/09/2020] [Indexed: 12/15/2022] Open
Abstract
Plant adaptations to changing environments rely on integrating external stimuli into internal responses. Brassinosteroids (BRs), a group of growth-promoting phytohormones, have been reported to act as signal molecules mediating these processes. BRs are perceived by cell surface receptor complex including receptor BRI1 and coreceptor BAK1, which subsequently triggers a signaling cascade that leads to inhibition of BIN2 and activation of BES1/BZR1 transcription factors. BES1/BZR1 can directly regulate the expression of thousands of downstream responsive genes. Recent studies in the model plant Arabidopsis demonstrated that BR biosynthesis and signal transduction, especially the regulatory components BIN2 and BES1/BZR1, are finely tuned by various environmental cues. Here, we summarize these research updates and give a comprehensive review of how BR biosynthesis and signaling are modulated by changing environments and how these changes regulate plant adaptive growth or stress tolerance.
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Potuschak T, Palatnik J, Schommer C, Sierro N, Ivanov NV, Kwon Y, Genschik P, Davière J, Otten L. Inhibition of Arabidopsis thaliana CIN-like TCP transcription factors by Agrobacterium T-DNA-encoded 6B proteins. Plant J 2020; 101:1303-1317. [PMID: 31659801 PMCID: PMC7187390 DOI: 10.1111/tpj.14591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 10/03/2019] [Indexed: 05/26/2023]
Abstract
Agrobacterium T-DNA-encoded 6B proteins cause remarkable growth effects in plants. Nicotiana otophora carries two cellular T-DNAs with three slightly divergent 6b genes (TE-1-6b-L, TE-1-6b-R and TE-2-6b) originating from a natural transformation event. In Arabidopsis thaliana, expression of 2×35S:TE-2-6b, but not 2×35S:TE-1-6b-L or 2×35S:TE-1-6b-R, led to plants with crinkly leaves, which strongly resembled mutants of the miR319a/TCP module. This module is composed of MIR319A and five CIN-like TCP (TEOSINTHE BRANCHED1, CYCLOIDEA and PROLIFERATING CELL NUCLEAR ANTIGEN BINDING FACTOR) genes (TCP2, TCP3, TCP4, TCP10 and TCP24) targeted by miR319a. The CIN-like TCP genes encode transcription factors and are required for cell division arrest at leaf margins during development. MIR319A overexpression causes excessive growth and crinkly leaves. TE-2-6b plants did not show increased miR319a levels, but the mRNA levels of the TCP4 target gene LOX2 were decreased, as in jaw-D plants. Co-expression of green fluorescent protein (GFP)-tagged TCPs with native or red fluorescent protein (RFP)-tagged TE-6B proteins led to an increase in TCP protein levels and formation of numerous cytoplasmic dots containing 6B and TCP proteins. Yeast double-hybrid experiments confirmed 6B/TCP binding and showed that TE-1-6B-L and TE-1-6B-R bind a smaller set of TCP proteins than TE-2-6B. A single nucleotide mutation in TE-1-6B-R enlarged its TCP-binding repertoire to that of TE-2-6B and caused a crinkly phenotype in Arabidopsis. Deletion analysis showed that TE-2-6B targets the TCP4 DNA-binding domain and directly interferes with transcriptional activation. Taken together, these results provide detailed insights into the mechanism of action of the N. otophora TE-encoded 6b genes.
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Affiliation(s)
- Thomas Potuschak
- Institut de Biologie Moléculaire des Plantes (IBMP)Rue du Général Zimmer 1267084StrasbourgFrance
| | - Javier Palatnik
- IBR‐CONICETPredio CCTOcampo y Esmeralda s/n2000RosarioArgentina
| | - Carla Schommer
- IBR‐CONICETPredio CCTOcampo y Esmeralda s/n2000RosarioArgentina
| | - Nicolas Sierro
- PMI R&DPhilip Morris Products S. A.Quai Jeanrenaud 52000NeuchâtelSwitzerland
| | - Nikolai V. Ivanov
- PMI R&DPhilip Morris Products S. A.Quai Jeanrenaud 52000NeuchâtelSwitzerland
| | - Yerim Kwon
- Institut de Biologie Moléculaire des Plantes (IBMP)Rue du Général Zimmer 1267084StrasbourgFrance
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes (IBMP)Rue du Général Zimmer 1267084StrasbourgFrance
| | - Jean‐Michel Davière
- Institut de Biologie Moléculaire des Plantes (IBMP)Rue du Général Zimmer 1267084StrasbourgFrance
| | - Léon Otten
- Institut de Biologie Moléculaire des Plantes (IBMP)Rue du Général Zimmer 1267084StrasbourgFrance
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9
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O'Leary BM, Oh GGK, Lee CP, Millar AH. Metabolite Regulatory Interactions Control Plant Respiratory Metabolism via Target of Rapamycin (TOR) Kinase Activation. Plant Cell 2020; 32:666-682. [PMID: 31888967 PMCID: PMC7054028 DOI: 10.1105/tpc.19.00157] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/18/2019] [Accepted: 12/23/2019] [Indexed: 05/03/2023]
Abstract
Respiration rate measurements provide an important readout of energy expenditure and mitochondrial activity in plant cells during the night. As plants inhabit a changing environment, regulatory mechanisms must ensure that respiratory metabolism rapidly and effectively adjusts to the metabolic and environmental conditions of the cell. Using a high-throughput approach, we have directly identified specific metabolites that exert transcriptional, translational, and posttranslational control over the nighttime O2 consumption rate (RN) in mature leaves of Arabidopsis (Arabidopsis thaliana). Multi-hour RN measurements following leaf disc exposure to a wide array of primary carbon metabolites (carbohydrates, amino acids, and organic acids) identified phosphoenolpyruvate (PEP), Pro, and Ala as the most potent stimulators of plant leaf RN Using metabolite combinations, we discovered metabolite-metabolite regulatory interactions controlling RN Many amino acids, as well as Glc analogs, were found to potently inhibit the RN stimulation by Pro and Ala but not PEP. The inhibitory effects of amino acids on Pro- and Ala-stimulated RN were mitigated by inhibition of the Target of Rapamycin (TOR) kinase signaling pathway. Supporting the involvement of TOR, these inhibitory amino acids were also shown to be activators of TOR kinase. This work provides direct evidence that the TOR signaling pathway in plants responds to amino acid levels by eliciting regulatory effects on respiratory energy metabolism at night, uniting a hallmark mechanism of TOR regulation across eukaryotes.
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Affiliation(s)
- Brendan M O'Leary
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Perth, Western Australia, Australia 6009
| | - Glenda Guek Khim Oh
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Perth, Western Australia, Australia 6009
| | - Chun Pong Lee
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Perth, Western Australia, Australia 6009
| | - A Harvey Millar
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Perth, Western Australia, Australia 6009
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10
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Gupta MK, Lenka SK, Gupta S, Rawal RK. Agonist, antagonist and signaling modulators of ABA receptor for agronomic and post-harvest management. Plant Physiol Biochem 2020; 148:10-25. [PMID: 31923734 DOI: 10.1016/j.plaphy.2019.12.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 05/18/2023]
Abstract
Abscisic acid (ABA) is a ubiquitous phytohormone, plays important roles in several physiological processes, including stress adaptation, flowering, seed germination, fruit ripening, and leaf senescence etc. ABA binds with START domain proteins called Pyrabactin Resistance1 (PYR1)/PYR1-like (PYL)/Regulatory Components of ABA Receptors (RCARs) and controls the activity of PP2C phosphatase proteins and in turn the ABA-dependent signaling pathway. Fourteen ABA receptors have been identified in the model plant Arabidopsis thaliana and have shown to be involved in various biological functions. Under field conditions, exogenous application of ABA produces inadequate physiological response due to its rapid conversion into the biologically inactive metabolites. ABA shows selective binding preferences to PYL receptor subtypes and hence produces pleiotropic physiological and phenotypic effects which limit the usage of ABA in agriculture. An agrochemical meant for ameliorating the undesirable physiological effect of the plant should ideally have positive biological attributes without affecting the normal growth, development, and yield. Therefore, to overcome the limitations of ABA for its usage in various agricultural applications, several types of ABA-mimicking agents have been developed. Many compounds have been identified as having significant ABA-agonist/antagonist activity and can be employed to reverse the excessive/moderate ABA action. The present review highlights the potential usage of ABA signaling modulators for managing agronomic and postharvest traits. Besides, designing, development and versatile usage of ABA-mimicking compounds displaying ABA agonists and antagonist activities are discussed in detail.
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Affiliation(s)
- Manish K Gupta
- TERI-Deakin Nanobiotechnology Centre, The Energy and Resources Institute (TERI), Gurugram, HR, India.
| | - Sangram K Lenka
- TERI-Deakin Nanobiotechnology Centre, The Energy and Resources Institute (TERI), Gurugram, HR, India
| | - Swati Gupta
- Amity Institute of Pharmacy, Amity University, Sector 125, Noida, UP, India
| | - Ravindra K Rawal
- Department of Chemistry, Maharishi Markandeshwar (Deemed to be University), Mullana, HR, India
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11
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Tarnowski K, Klimecka M, Ciesielski A, Goch G, Kulik A, Fedak H, Poznański J, Lichocka M, Pierechod M, Engh RA, Dadlez M, Dobrowolska G, Bucholc M. Two SnRK2-Interacting Calcium Sensor Isoforms Negatively Regulate SnRK2 Activity by Different Mechanisms. Plant Physiol 2020; 182:1142-1160. [PMID: 31699848 PMCID: PMC6997710 DOI: 10.1104/pp.19.00900] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/28/2019] [Indexed: 05/07/2023]
Abstract
SNF1-related protein kinases 2 (SnRK2s) are key signaling elements regulating abscisic acid-dependent plant development and responses to environmental stresses. Our previous data showed that the SnRK2-interacting Calcium Sensor (SCS) inhibits SnRK2 activity. Use of alternative transcription start sites located within the Arabidopsis (Arabidopsis thaliana) AtSCS gene results in two in-frame transcripts and subsequently two proteins, that differ only by the sequence position of the N terminus. We previously described the longer AtSCS-A, and now describe the shorter AtSCS-B and compare the two isoforms. The two isoforms differ substantially in their expression profiles in plant organs and in response to environmental stresses, in their calcium binding properties, and in their conformational dynamics in the presence and absence of Ca2+ Only AtSCS-A has the features of a calcium sensor. Both forms inhibit SnRK2 activity, but while AtSCS-A requires calcium for inhibition, AtSCS-B does not. Analysis of Arabidopsis plants stably expressing 35S::AtSCS-A-c-myc or 35S::AtSCS-B-c-myc in the scs-1 knockout mutant background revealed that, in planta, both forms are negative regulators of abscisic acid-induced SnRK2 activity and regulate plant resistance against water deficit. Moreover, the data highlight biochemical, biophysical, and functional properties of EF-hand-like motifs in plant proteins.
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Affiliation(s)
- Krzysztof Tarnowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Maria Klimecka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Arkadiusz Ciesielski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
- Warsaw University, Department of Chemistry, 02-093 Warsaw, Poland
| | - Grażyna Goch
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Anna Kulik
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Halina Fedak
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Jarosław Poznański
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Małgorzata Lichocka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Marcin Pierechod
- The Norwegian Center for Structure Biology, Institute of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
| | - Richard A Engh
- The Norwegian Center for Structure Biology, Institute of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
| | - Michał Dadlez
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
- University of Warsaw, Institute of Genetics and Biotechnology, 02-106 Warsaw, Poland
| | - Grażyna Dobrowolska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Maria Bucholc
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
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12
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Lei W, Li Y, Yao X, Qiao K, Wei L, Liu B, Zhang D, Lin H. NAP is involved in GA-mediated chlorophyll degradation and leaf senescence by interacting with DELLAs in Arabidopsis. Plant Cell Rep 2020; 39:75-87. [PMID: 31646371 DOI: 10.1007/s00299-019-02474-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 09/18/2019] [Indexed: 05/29/2023]
Abstract
RGA/GAI and NAP interacted with each other, and NAP was involved in GA signaling as a role of regulating age-dependent and dark-induced leaf senescence in Arabidopsis. Leaf senescence is a significant biological process which is beneficial for plant growth, development, and generation alternation in Arabidopsis. Recent researches have shown gibberellins (GAs) could accelerate leaf senescence. Nevertheless, the GA signaling involved in leaf senescence process remains elusive. Here, we reported a new potential regulation mechanism of GA-mediated chlorophyll degradation and leaf senescence. In this study, we confirmed that NAP positively regulated age-dependent and dark-induced leaf senescence and NAP knockout mutant nap was hyposensitive to GA3 (an active form of GA) treatment. DELLA family proteins with highly conserved structural domain function as master growth repressors that integrated GA signaling and leaf senescence. We validated RGA and GAI could interact with NAP in vitro and in vivo, and subsequently impaired the transcriptional activities of NAP to induce SAG113 and AAO3 expression in nap protoplasts. Taken together, we suggest that NAP is a novel component of the regulatory network that modulates the progress of leaf senescence in GA signaling.
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Affiliation(s)
- Wei Lei
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China
| | - Yan Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China
| | - Xiuhong Yao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China
| | - Kang Qiao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China
| | - Lin Wei
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China
| | - Baohui Liu
- School of Life Science, Guangzhou University, Guangzhou, 510006, China
| | - Dawei Zhang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China.
| | - Honghui Lin
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China.
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13
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Caldo KMP, Xu Y, Falarz L, Jayawardhane K, Acedo JZ, Chen G. Arabidopsis CTP:phosphocholine cytidylyltransferase 1 is phosphorylated and inhibited by sucrose nonfermenting 1-related protein kinase 1 (SnRK1). J Biol Chem 2019; 294:15862-15874. [PMID: 31439667 PMCID: PMC6816107 DOI: 10.1074/jbc.ra119.008047] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/19/2019] [Indexed: 11/06/2022] Open
Abstract
De novo phosphatidylcholine (PC) biosynthesis via the Kennedy pathway involves highly endergonic biochemical reactions that must be fine-tuned with energy homeostasis. Previous studies have shown that CTP:phosphocholine cytidylyltransferase (CCT) is an important regulatory enzyme in this pathway and that its activity can be controlled at both transcriptional and posttranslational levels. Here we identified an important additional mechanism regulating plant CCT1 activity. Comparative analysis revealed that Arabidopsis CCT1 (AtCCT1) contains catalytic and membrane-binding domains that are homologous to those of rat CCT1. In contrast, the C-terminal phosphorylation domain important for stringent regulation of rat CCT1 was apparently missing in AtCCT1. Instead, we found that AtCCT1 contains a putative consensus site (Ser-187) for modification by sucrose nonfermenting 1-related protein kinase 1 (SnRK1 or KIN10/SnRK1.1), involved in energy homeostasis. Phos-tag SDS-PAGE coupled with MS analysis disclosed that SnRK1 indeed phosphorylates AtCCT1 at Ser-187, and we found that AtCCT1 phosphorylation substantially reduces its activity by as much as 70%. An S187A variant exhibited decreased activity, indicating the importance of Ser-187 in catalysis, and this variant was less susceptible to SnRK1-mediated inhibition. Protein truncation and liposome binding studies indicated that SnRK1-mediated AtCCT1 phosphorylation directly affects the catalytic domain rather than interfering with phosphatidate-mediated AtCCT1 activation. Overexpression of the AtCCT1 catalytic domain in Nicotiana benthamiana leaves increased PC content, and SnRK1 co-expression reduced this effect. Taken together, our results suggest that SnRK1 mediates the phosphorylation and concomitant inhibition of AtCCT1, revealing an additional mode of regulation for this key enzyme in plant PC biosynthesis.
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Affiliation(s)
- Kristian Mark P Caldo
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Yang Xu
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Lucas Falarz
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Kethmi Jayawardhane
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Jeella Z Acedo
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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14
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Ruta V, Longo C, Boccaccini A, Madia VN, Saccoliti F, Tudino V, Di Santo R, Lorrai R, Dello Ioio R, Sabatini S, Costi R, Costantino P, Vittorioso P. Inhibition of Polycomb Repressive Complex 2 activity reduces trimethylation of H3K27 and affects development in Arabidopsis seedlings. BMC Plant Biol 2019; 19:429. [PMID: 31619182 PMCID: PMC6796367 DOI: 10.1186/s12870-019-2057-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 09/26/2019] [Indexed: 05/21/2023]
Abstract
BACKGROUND Polycomb repressive complex 2 (PRC2) is an epigenetic transcriptional repression system, whose catalytic subunit (ENHANCER OF ZESTE HOMOLOG 2, EZH2 in animals) is responsible for trimethylating histone H3 at lysine 27 (H3K27me3). In mammals, gain-of-function mutations as well as overexpression of EZH2 have been associated with several tumors, therefore making this subunit a suitable target for the development of selective inhibitors. Indeed, highly specific small-molecule inhibitors of EZH2 have been reported. In plants, mutations in some PRC2 components lead to embryonic lethality, but no trial with any inhibitor has ever been reported. RESULTS We show here that the 1,5-bis (3-bromo-4-methoxyphenyl)penta-1,4-dien-3-one compound (RDS 3434), previously reported as an EZH2 inhibitor in human leukemia cells, is active on the Arabidopsis catalytic subunit of PRC2, since treatment with the drug reduces the total amount of H3K27me3 in a dose-dependent fashion. Consistently, we show that the expression level of two PRC2 targets is significantly increased following treatment with the RDS 3434 compound. Finally, we show that impairment of H3K27 trimethylation in Arabidopsis seeds and seedlings affects both seed germination and root growth. CONCLUSIONS Our results provide a useful tool for the plant community in investigating how PRC2 affects transcriptional control in plant development.
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Affiliation(s)
- Veronica Ruta
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Chiara Longo
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Alessandra Boccaccini
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Valentina Noemi Madia
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Francesco Saccoliti
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Valeria Tudino
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Roberto Di Santo
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Riccardo Lorrai
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Raffaele Dello Ioio
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Sabrina Sabatini
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Roberta Costi
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Paolo Costantino
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Paola Vittorioso
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
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15
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Lochmanová G, Ihnatová I, Kuchaříková H, Brabencová S, Zachová D, Fajkus J, Zdráhal Z, Fojtová M. Different Modes of Action of Genetic and Chemical Downregulation of Histone Deacetylases with Respect to Plant Development and Histone Modifications. Int J Mol Sci 2019; 20:ijms20205093. [PMID: 31615119 PMCID: PMC6829310 DOI: 10.3390/ijms20205093] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 02/02/2023] Open
Abstract
A high degree of developmental plasticity enables plants to adapt to continuous, often unfavorable and unpredictable changes in their environment. At the molecular level, adaptive advantages for plants are primarily provided by epigenetic machinery including DNA methylation, histone modifications, and the activity of noncoding RNA molecules. Using a mass spectrometry-based proteomic approach, we examined the levels of acetylated histone peptide forms in Arabidopsis plants with a loss of function of histone deacetylase 6 (HDA6), and in plants germinated in the presence of HDA inhibitors trichostatin A (TSA) and sodium butyrate (NaB). Our analyses revealed particular lysine sites at histone sequences targeted by the HDA6 enzyme, and by TSA- and NaB-sensitive HDAs. Compared with plants exposed to drugs, more dramatic changes in the overall profiles of histone post-translational modifications were identified in hda6 mutants. However, loss of HDA6 was not sufficient by itself to induce hyperacetylation to the maximum degree, implying complementary activities of other HDAs. In contrast to hda6 mutants that did not exhibit any obvious phenotypic defects, the phenotypes of seedlings exposed to HDA inhibitors were markedly affected, showing that the effect of these drugs on early plant development is not limited to the modulation of histone acetylation levels.
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Affiliation(s)
- Gabriela Lochmanová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
| | - Ivana Ihnatová
- RECETOX, Faculty of Science, Masaryk University, 62500 Brno, Czech Republic.
| | - Hana Kuchaříková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 62500 Brno, Czech Republic.
| | - Sylva Brabencová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 62500 Brno, Czech Republic.
| | - Dagmar Zachová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 62500 Brno, Czech Republic.
| | - Zbyněk Zdráhal
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 62500 Brno, Czech Republic.
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic.
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16
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Abstract
The microtubule-severing enzyme katanin (KTN1) regulates the organization and turnover of microtubule arrays by the localized breakdown of microtubule polymers. In land plants, KTN1 activity is essential for the formation of linearly organized cortical microtubule arrays that determine the axis of cell expansion. Cell biological studies have shown that even though KTN1 binds to the sidewalls of single and bundled microtubules, severing activity is restricted to microtubule cross-over and nucleation sites, indicating that cells contain protective mechanisms to prevent indiscriminate microtubule severing. Here, we show that the microtubule-bundling protein MAP65-1 inhibits KTN1-mediated microtubule severing in vitro. Severing is inhibited at bundled microtubule segments and the severing rate of nonbundled microtubules is reduced by MAP65-1 in a concentration-dependent manner. Using various MAP65-1 mutant proteins, we demonstrate that efficient cross-linking of microtubules is crucial for this protective effect and that microtubule binding alone is not sufficient. Reduced severing due to microtubule bundling by MAP65-1 correlated to decreased binding of KTN1 to these microtubules. Taken together, our work reveals that cross-linking of microtubules by MAP65-1 confers resistance to severing by inhibiting the binding of KTN1 and identifies the structural features of MAP65-1 that are important for this activity.
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Affiliation(s)
- Graham M Burkart
- Department of Biology and Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO 63130
| | - Ram Dixit
- Department of Biology and Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO 63130
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17
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Kumar R, Duhamel M, Coutant E, Ben-Nahia E, Mercier R. Antagonism between BRCA2 and FIGL1 regulates homologous recombination. Nucleic Acids Res 2019; 47:5170-5180. [PMID: 30941419 PMCID: PMC6547764 DOI: 10.1093/nar/gkz225] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 02/06/2023] Open
Abstract
Homologous recombination (HR) maintains genome stability by promoting accurate DNA repair. Two recombinases, RAD51 and DMC1, are central to HR repair and form dynamic nucleoprotein filaments in vivo under tight regulation. However, the interplay between positive and negative regulators to control the dynamic assembly/disassembly of RAD51/DMC1 filaments in multicellular eukaryotes remains poorly characterized. Here, we report an antagonism between BRCA2, a well-studied positive mediator of RAD51/DMC1, and FIDGETIN-LIKE-1 (FIGL1), which we previously proposed as a negative regulator of RAD51/DMC1. Through forward genetic screen, we identified a mutation in one of the two Arabidopsis BRCA2 paralogs that suppresses the meiotic phenotypes of figl1. Consistent with the antagonistic roles of BRCA2 and FIGL1, the figl1 mutation in the brca2 background restores RAD51/DMC1 focus formation and homologous chromosome interaction at meiosis, and RAD51 focus formation in somatic cells. This study shows that BRCA2 and FIGL1 have antagonistic effects on the dynamics of RAD51/DMC1-dependent DNA transactions to promote accurate HR repair.
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Affiliation(s)
- Rajeev Kumar
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Marine Duhamel
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Eve Coutant
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Emna Ben-Nahia
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Raphael Mercier
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
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18
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Hu T, Huang C, He Y, Castillo-González C, Gui X, Wang Y, Zhang X, Zhou X. βC1 protein encoded in geminivirus satellite concertedly targets MKK2 and MPK4 to counter host defense. PLoS Pathog 2019; 15:e1007728. [PMID: 30998777 PMCID: PMC6499421 DOI: 10.1371/journal.ppat.1007728] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 05/03/2019] [Accepted: 03/24/2019] [Indexed: 12/30/2022] Open
Abstract
Plant viruses have evolved multiple strategies to overcome host defense to establish an infection. Here, we identified two components of a host mitogen-activated protein kinase (MAPK) cascade, MKK2 and MPK4, as bona fide targets of the βC1 protein encoded by the betasatellite of tomato yellow leaf curl China virus (TYLCCNV). βC1 interacts with the kinase domain of MKK2 and inhibits its activity. In vivo, βC1 suppresses flagellin-induced MAPK activation and downstream responses by targeting MKK2. Furthermore, βC1 also interacts with MPK4 and inhibits its kinase activity. TYLCCNV infection induces the activation of the MAPK cascade, mutation in MKK2 or MPK4 renders the plant more susceptible to TYLCCNV, and can complement the lack of βC1. This work shows for the first time that a plant virus both activates and suppresses a MAPK cascade, and the discovery of the ability of βC1 to selectively interfere with the host MAPK activation illustrates a novel virulence function and counter-host defense mechanism of geminiviruses.
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Affiliation(s)
- Tao Hu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States of America
| | - Changjun Huang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yuting He
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Claudia Castillo-González
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States of America
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, United States of America
| | - Xiaojian Gui
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xiuren Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States of America
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, United States of America
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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19
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Tang H, de Keijzer J, Overdijk EJR, Sweep E, Steentjes M, Vermeer JEM, Janson ME, Ketelaar T. Exocyst subunit Sec6 is positioned by microtubule overlaps in the moss phragmoplast prior to cell plate membrane arrival. J Cell Sci 2019; 132:jcs222430. [PMID: 30635445 DOI: 10.1242/jcs.222430] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 01/02/2019] [Indexed: 12/21/2022] Open
Abstract
During plant cytokinesis a radially expanding membrane-enclosed cell plate is formed from fusing vesicles that compartmentalizes the cell in two. How fusion is spatially restricted to the site of cell plate formation is unknown. Aggregation of cell-plate membrane starts near regions of microtubule overlap within the bipolar phragmoplast apparatus of the moss Physcomitrella patens Since vesicle fusion generally requires coordination of vesicle tethering and subsequent fusion activity, we analyzed the subcellular localization of several subunits of the exocyst, a tethering complex active during plant cytokinesis. We found that the exocyst complex subunit Sec6 but not the Sec3 or Sec5 subunits localized to microtubule overlap regions in advance of cell plate construction in moss. Moreover, Sec6 exhibited a conserved physical interaction with an ortholog of the Sec1/Munc18 protein KEULE, an important regulator for cell-plate membrane vesicle fusion in Arabidopsis Recruitment of the P. patens protein KEULE and vesicles to the early cell plate was delayed upon Sec6 gene silencing. Our findings, thus, suggest that vesicle-vesicle fusion is, in part, enabled by a pool of exocyst subunits at microtubule overlaps, which is recruited independently of vesicle delivery.
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Affiliation(s)
- Han Tang
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Jeroen de Keijzer
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Elysa J R Overdijk
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Els Sweep
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Maikel Steentjes
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Joop E M Vermeer
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| | - Marcel E Janson
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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20
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Abstract
Noncoding RNAs perform diverse regulatory functions in living cells. In plants, two RNA polymerase II-related enzymes, RNA polymerases IV and V (Pol IV and V), specialize in the synthesis of noncoding RNAs that silence a subset of transposable elements and genes via RNA-directed DNA methylation (RdDM). In this process, Pol IV partners with RNA-dependent RNA polymerase 2 (RDR2) to produce double-stranded RNAs that are then cut by an RNase III enzyme, Dicer-like 3 (DCL3), into 24 nt small interfering RNAs (siRNAs). The siRNAs are loaded into an Argonaute family protein, primarily AGO4, and guide the complex to complementary DNA target sequences where RdDM and repressive chromatin modifications ensue. The dependence of 24 nt siRNA biogenesis on Pol IV and RDR2 has been known for more than a decade, but the elusive pre-siRNA transcripts synthesized by Pol IV and RDR2 have only recently been identified. This chapter describes the approaches that enabled our identification of Pol IV/RDR2-dependent RNAs (P4R2 RNAs) in Arabidopsis thaliana. These included the use of a triple Dicer mutant (dcl2 dcl3 dcl4) to cause P4R2 RNAs to accumulate, genome-wide identification and mapping of P4R2 RNAs using a modified Illumina small RNA-Seq protocol, and multiple bioinformatic pipelines for data analysis and displaying results.
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Affiliation(s)
- Todd Blevins
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, USA.
- Department of Biology, Indiana University, Bloomington, IN, USA.
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA.
- Institut de Biologie Moléculaire des Plantes, CNRS UPR2357, Université de Strasbourg, Strasbourg, France.
| | - Ram Podicheti
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA
- School of Informatics, Computing and Engineering, Indiana University, Bloomington, IN, USA
| | - Craig S Pikaard
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
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21
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Lian H, Xu P, He S, Wu J, Pan J, Wang W, Xu F, Wang S, Pan J, Huang J, Yang HQ. Photoexcited CRYPTOCHROME 1 Interacts Directly with G-Protein β Subunit AGB1 to Regulate the DNA-Binding Activity of HY5 and Photomorphogenesis in Arabidopsis. Mol Plant 2018; 11:1248-1263. [PMID: 30176372 DOI: 10.1016/j.molp.2018.08.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/25/2018] [Accepted: 08/23/2018] [Indexed: 05/25/2023]
Abstract
Light and the heterotrimeric G-protein are known to antagonistically regulate photomorphogenesis in Arabidopsis. However, whether light and G-protein coordinate the regulation of photomorphogenesis is largely unknown. Here we show that the blue light photoreceptor cryptochrome 1 (CRY1) physically interacts with the G-protein β subunit, AGB1, in a blue light-dependent manner. We also show that AGB1 directly interacts with HY5, a basic leucine zipper transcriptional factor that acts as a critical positive regulator of photomorphogenesis, to inhibit its DNA-binding activity. Genetic studies suggest that CRY1 acts partially through AGB1, and AGB1 acts partially through HY5 to regulate photomorphogenesis. Moreover, we demonstrate that blue light-triggered interaction of CRY1 with AGB1 promotes the dissociation of HY5 from AGB1. Our results suggest that the CRY1 signaling mechanism involves positive regulation of the DNA-binding activity of HY5 mediated by the CRY1-AGB1 interaction, which inhibits the association of AGB1 with HY5. We propose that the antagonistic regulation of HY5 DNA-binding activity by CRY1 and AGB1 may allow plants to balance light and G-protein signaling and optimize photomorphogenesis.
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Affiliation(s)
- Hongli Lian
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Pengbo Xu
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shengbo He
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jun Wu
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jian Pan
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wenxiu Wang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Feng Xu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Sheng Wang
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Junsong Pan
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jirong Huang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Hong-Quan Yang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
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22
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Zhai Z, Keereetaweep J, Liu H, Feil R, Lunn JE, Shanklin J. Trehalose 6-Phosphate Positively Regulates Fatty Acid Synthesis by Stabilizing WRINKLED1. Plant Cell 2018; 30:2616-2627. [PMID: 30249634 PMCID: PMC6241258 DOI: 10.1105/tpc.18.00521] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/24/2018] [Accepted: 09/24/2018] [Indexed: 05/18/2023]
Abstract
WRINKLED1 (WRI1), the transcriptional activator of fatty acid synthesis, was recently identified as a target of KIN10, a catalytic α-subunit of the SUCROSE-NON-FERMENTING1-RELATED PROTEIN KINASE1 (SnRK1). We tested the hypothesis that trehalose 6-phosphate (T6P), a signal of cellular sucrose status, can regulate fatty acid synthesis by inhibiting SnRK1. Incubation of Brassica napus suspension cells in medium containing T6P, or overexpression of the Escherichia coli T6P synthase, OtsA, in Nicotiana benthamiana, significantly increased T6P levels, WRI1 levels, and fatty acid synthesis rates. T6P directly bound to purified recombinant KIN10 with an equilibrium dissociation constant (K d) of 32 ± 6 μM based on microscale thermophoresis. GEMINIVIRUS REP-INTERACTING KINASE1 (GRIK1) bound to KIN10 (K d 19 ± 3 μM) and activated it by phosphorylation. In the presence of T6P, the GRIK1-KIN10 association was weakened by more than 3-fold (K d 68 ± 9.8 μM), which reduced both the phosphorylation of KIN10 and its activity. T6P-dependent inhibition of SnRK1 activity was reduced in extracts of individual Arabidopsis thaliana grik1 and grik2 mutants relative to the wild type, while SnRK1 activity in grik1 grik2 extracts was enhanced by T6P. These results indicate that the T6P sensitivity of SnRK1 in vivo is GRIK1/GRIK2 dependent. Based on our findings, we propose a mechanistic model that links sugar signaling and fatty acid homeostasis.
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Affiliation(s)
- Zhiyang Zhai
- Department of Biology, Brookhaven National Laboratory, Upton, New York 11973
| | | | - Hui Liu
- Department of Biology, Brookhaven National Laboratory, Upton, New York 11973
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - John Shanklin
- Department of Biology, Brookhaven National Laboratory, Upton, New York 11973
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23
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Dumont S, Bykova NV, Khaou A, Besserour Y, Dorval M, Rivoal J. Arabidopsis thaliana alcohol dehydrogenase is differently affected by several redox modifications. PLoS One 2018; 13:e0204530. [PMID: 30252897 PMCID: PMC6155552 DOI: 10.1371/journal.pone.0204530] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/10/2018] [Indexed: 11/19/2022] Open
Abstract
In plant cells, many stresses, including low oxygen availability, result in a higher production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). These molecules can lead to redox-dependent post-translational modification of proteins Cys residues. Here, we studied the effect of different redox modifications on alcohol dehydrogenase (ADH) from Arabidopsis thaliana. ADH catalyzes the last step of the ethanol fermentation pathway used by plants to cope with energy deficiency during hypoxic stress. Arabidopsis suspension cell cultures showed decreased ADH activity upon exposure to H2O2, but not to the thiol oxidizing agent diamide. We purified recombinant ADH and observed a significant decrease in the enzyme activity by treatments with H2O2 and diethylamine NONOate (DEA/NO). Treatments leading to the formation of a disulfide bond between ADH and glutathione (protein S-glutathionylation) had no negative effect on the enzyme activity. LC-MS/MS analysis showed that Cys47 and Cys243 could make a stable disulfide bond with glutathione, suggesting redox sensitivity of these residues. Mutation of ADH Cys47 to Ser caused an almost complete loss of the enzyme activity while the Cys243 to Ser mutant had increased specific activity. Incubation of ADH with NAD+ or NADH prevented inhibition of the enzyme by H2O2 or DEA/NO. These results suggest that binding of ADH with its cofactors may limit availability of Cys residues to redox modifications. Our study demonstrates that ADH from A. thaliana is subject to different redox modifications. Implications of ADH sensitivity to ROS and RNS during hypoxic stress conditions are discussed.
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Affiliation(s)
- Sébastien Dumont
- Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Québec, Canada
| | - Natalia V. Bykova
- Morden Research and Development Centre, Agriculture and Agri-Food Canada, Morden, Manitoba, Canada
| | - Alexia Khaou
- Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Québec, Canada
| | - Yasmine Besserour
- Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Québec, Canada
| | - Maude Dorval
- Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Québec, Canada
| | - Jean Rivoal
- Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Québec, Canada
- * E-mail:
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24
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Zhang Y, Zhang Y, McFarlane HE, Obata T, Richter AS, Lohse M, Grimm B, Persson S, Fernie AR, Giavalisco P. Inhibition of TOR Represses Nutrient Consumption, Which Improves Greening after Extended Periods of Etiolation. Plant Physiol 2018; 178:101-117. [PMID: 30049747 PMCID: PMC6130015 DOI: 10.1104/pp.18.00684] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 07/15/2018] [Indexed: 05/08/2023]
Abstract
Upon illumination, etiolated seedlings experience a transition from heterotrophic to photoautotrophic growth. During this process, the tetrapyrrole biosynthesis pathway provides chlorophyll for photosynthesis. This pathway has to be tightly controlled to prevent the accumulation of photoreactive metabolites and to provide stoichiometric amounts of chlorophyll for its incorporation into photosynthetic protein complexes. Therefore, plants have evolved regulatory mechanisms to synchronize the biosynthesis of chlorophyll and chlorophyll-binding proteins. Two phytochrome-interacting factors (PIF1 and PIF3) and the DELLA proteins, which are controlled by the gibberellin pathway, are key regulators of this process. Here, we show that impairment of TARGET OF RAPAMYCIN (TOR) activity in Arabidopsis (Arabidopsis thaliana), either by mutation of the TOR complex component RAPTOR1B or by treatment with TOR inhibitors, leads to a significantly reduced accumulation of the photoreactive chlorophyll precursor protochlorophyllide in darkness but an increased greening rate of etiolated seedlings after exposure to light. Detailed profiling of metabolic, transcriptomic, and physiological parameters revealed that the TOR-repressed lines not only grow slower, they grow in a nutrient-saving mode, which allows them to resist longer periods of low nutrient availability. Our results also indicated that RAPTOR1B acts upstream of the gibberellin-DELLA pathway and its mutation complements the repressed greening phenotype of pif1 and pif3 after etiolation.
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Affiliation(s)
- Yi Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Youjun Zhang
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Heather E McFarlane
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- School of Biosciences, University of Melbourne, Parkville, Melbourne, Victoria 3010, Australia
| | - Toshihiro Obata
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Institute of Agriculture and Natural Resources, University of Nebraska, Lincoln, Nebraska 68588
| | - Andreas S Richter
- Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, 10115 Berlin, Germany
| | - Mark Lohse
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Targenomix, 14476 Potsdam, Germany
| | - Bernhard Grimm
- Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, 10115 Berlin, Germany
| | - Staffan Persson
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- School of Biosciences, University of Melbourne, Parkville, Melbourne, Victoria 3010, Australia
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Patrick Giavalisco
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
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25
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Watanabe B, Kirikae H, Koeduka T, Takeuchi Y, Asai T, Naito Y, Tokuoka H, Horoiwa S, Nakagawa Y, Shimizu BI, Mizutani M, Hiratake J. Synthesis and inhibitory activity of mechanism-based 4-coumaroyl-CoA ligase inhibitors. Bioorg Med Chem 2018; 26:2466-2474. [PMID: 29685682 DOI: 10.1016/j.bmc.2018.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 04/02/2018] [Accepted: 04/03/2018] [Indexed: 10/17/2022]
Abstract
4-Coumaroyl-CoA ligase (4CL) is ubiquitous in the plant kingdom, and plays a central role in the biosynthesis of phenylpropanoids such as lignins, flavonoids, and coumarins. 4CL catalyzes the formation of the coenzyme A thioester of cinnamates such as 4-coumaric, caffeic, and ferulic acids, and the regulatory position of 4CL in the phenylpropanoid pathway renders the enzyme an attractive target that controls the composition of phenylpropanoids in plants. In this study, we designed and synthesized mechanism-based inhibitors for 4CL in order to develop useful tools for the investigation of physiological functions of 4CL and chemical agents that modulate plant growth with the ultimate goal to produce plant biomass that exhibits features that are beneficial to humans. The acylsulfamide backbone of the inhibitors in this study was adopted as a mimic of the acyladenylate intermediates in the catalytic reaction of 4CL. These acylsulfamide inhibitors and the important synthetic intermediates were fully characterized using two-dimensional NMR spectroscopy. Five 4CL proteins with distinct substrate specificity from four plant species, i.e., Arabidopsis thaliana, Glycine max (soybean), Populus trichocarpa (poplar), and Petunia hybrida (petunia), were used to evaluate the inhibitory activity, and the half-maximum inhibitory concentration (IC50) of each acylsulfamide in the presence of 4-coumaric acid (100 µM) was determined as an index of inhibitory activity. The synthetic acylsulfamides used in this study inhibited the 4CLs with IC50 values ranging from 0.10 to 722 µM, and the IC50 values of the most potent inhibitors for each 4CL were 0.10-2.4 µM. The structure-activity relationship observed in this study revealed that both the presence and the structure of the acyl group of the synthetic inhibitors strongly affect the inhibitory activity, and indicates that 4CL recognizes the acylsulfamide inhibitors as acyladenylate mimics.
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Affiliation(s)
- Bunta Watanabe
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
| | - Hiroaki Kirikae
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Takao Koeduka
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Yoshinori Takeuchi
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Tomoki Asai
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Yoshiyuki Naito
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Hideya Tokuoka
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Shinri Horoiwa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Yoshiaki Nakagawa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Bun-Ichi Shimizu
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Masaharu Mizutani
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Jun Hiratake
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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26
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Arenas-Alfonseca L, Gotor C, Romero LC, García I. ß-Cyanoalanine Synthase Action in Root Hair Elongation is Exerted at Early Steps of the Root Hair Elongation Pathway and is Independent of Direct Cyanide Inactivation of NADPH Oxidase. Plant Cell Physiol 2018; 59:1072-1083. [PMID: 29490083 DOI: 10.1093/pcp/pcy047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/22/2018] [Indexed: 05/24/2023]
Abstract
In Arabidopsis thaliana, cyanide is produced concomitantly with ethylene biosynthesis and is mainly detoxified by the ß-cyanoalanine synthase CAS-C1. In roots, CAS-C1 activity is essential to maintain a low level of cyanide for proper root hair development. Root hair elongation relies on polarized cell expansion at the growing tip, and we have observed that CAS-C1 locates in mitochondria and accumulates in root hair tips during root hair elongation, as shown by observing the fluorescence in plants transformed with the translational construct ProC1:CASC1-GFP, containing the complete CAS-C1 gene fused to green fluorescent protein (GFP). Mutants in the SUPERCENTIPEDE (SCN1) gene, that regulate the NADPH oxidase gene ROOT HAIR DEFECTIVE 2 (RHD2)/AtrbohC, are affected at the very early steps of the development of root hair that do not elongate and do not show a preferential localization of the GFP accumulation in the tips of the root hair primordia. Root hairs of mutants in CAS-C1 or RHD2/AtrbohC, whose protein product catalyzes the generation of ROS and the Ca2+ gradient, start to grow out correctly, but they do not elongate. Genetic crosses between the cas-c1 mutant and scn1 or rhd2 mutants were performed, and the detailed phenotypic and molecular characterization of the double mutants demonstrates that scn1 mutation is epistatic to cas-c1 and cas-c1 is epistatic to rhd2 mutation, indicating that CAS-C1 acts in early steps of the root hair development process. Moreover, our results show that the role of CAS-C1 in root hair elongation is independent of H2O2 production and of a direct NADPH oxidase inhibition by cyanide.
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Affiliation(s)
- Lucía Arenas-Alfonseca
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
| | - Cecilia Gotor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
| | - Luis C Romero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
| | - Irene García
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
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27
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Chen W, Gong P, Guo J, Li H, Li R, Xing W, Yang Z, Guan Y. Glycolysis regulates pollen tube polarity via Rho GTPase signaling. PLoS Genet 2018; 14:e1007373. [PMID: 29702701 PMCID: PMC5942846 DOI: 10.1371/journal.pgen.1007373] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 05/09/2018] [Accepted: 04/19/2018] [Indexed: 12/25/2022] Open
Abstract
As a universal energy generation pathway utilizing carbon metabolism, glycolysis plays an important housekeeping role in all organisms. Pollen tubes expand rapidly via a mechanism of polarized growth, known as tip growth, to deliver sperm for fertilization. Here, we report a novel and surprising role of glycolysis in the regulation of growth polarity in Arabidopsis pollen tubes via impingement of Rho GTPase-dependent signaling. We identified a cytosolic phosphoglycerate kinase (pgkc-1) mutant with accelerated pollen germination and compromised pollen tube growth polarity. pgkc-1 mutation greatly diminished apical exocytic vesicular distribution of REN1 RopGAP (Rop GTPase activating protein), leading to ROP1 hyper-activation at the apical plasma membrane. Consequently, pgkc-1 pollen tubes contained higher amounts of exocytic vesicles and actin microfilaments in the apical region, and showed reduced sensitivity to Brefeldin A and Latrunculin B, respectively. While inhibition of mitochondrial respiration could not explain the pgkc-1 phenotype, the glycolytic activity is indeed required for PGKc function in pollen tubes. Moreover, the pgkc-1 pollen tube phenotype was mimicked by the inhibition of another glycolytic enzyme. These findings highlight an unconventional regulatory function for a housekeeping metabolic pathway in the spatial control of a fundamental cellular process. Glycolysis, which breaks down glucose to produce energy, has long been considered a “housekeeping” pathway in living cells, i.e., it helps maintain basic cellular functions. Here, we found that the glycolysis pathway plays an unconventional regulatory role in cell polarity, i.e., the intrinsic asymmetry in the shape, structure, and organization of cellular components. Mutation in the gene encoding the glycolytic enzyme cytosolic phosphoglycerate kinase (PGKc) leads to swollen and shorter pollen tubes in Arabidopsis thaliana, which is associated with the over-activation of Rho GTPase—a master regulator of cell polarity. Our results suggest that this phenomenon is caused by a specific regulatory role of cytosolic glycolysis rather than the global energy supply or moonlighting functions of glycolytic enzymes that modulate pollen tube growth polarity. Our findings shed light on the diverse biological roles of glycolysis in plants beyond simple “housekeeping” functions.
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Affiliation(s)
- Wei Chen
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - Pingping Gong
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Jingzhe Guo
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Center for Plant Cell Biology, Institute of Integrated Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, California, United States of America
| | - Hui Li
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
- Center for Plant Cell Biology, Institute of Integrated Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, California, United States of America
| | - Ruizi Li
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Weiman Xing
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
| | - Zhenbiao Yang
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Center for Plant Cell Biology, Institute of Integrated Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, California, United States of America
| | - Yuefeng Guan
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- * E-mail:
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28
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Holland CK, Berkovich DA, Kohn ML, Maeda H, Jez JM. Structural basis for substrate recognition and inhibition of prephenate aminotransferase from Arabidopsis. Plant J 2018; 94:304-314. [PMID: 29405514 DOI: 10.1111/tpj.13856] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/25/2018] [Accepted: 01/29/2018] [Indexed: 05/23/2023]
Abstract
Aromatic amino acids are protein building blocks and precursors to a number of plant natural products, such as the structural polymer lignin and a variety of medicinally relevant compounds. Plants make tyrosine and phenylalanine by a different pathway from many microbes; this pathway requires prephenate aminotransferase (PAT) as the key enzyme. Prephenate aminotransferase produces arogenate, the unique and immediate precursor for both tyrosine and phenylalanine in plants, and also has aspartate aminotransferase (AAT) activity. The molecular mechanisms governing the substrate specificity and activation or inhibition of PAT are currently unknown. Here we present the X-ray crystal structures of the wild-type and various mutants of PAT from Arabidopsis thaliana (AtPAT). Steady-state kinetic and ligand-binding analyses identified key residues, such as Glu108, that are involved in both keto acid and amino acid substrate specificities and probably contributed to the evolution of PAT activity among class Ib AAT enzymes. Structures of AtPAT mutants co-crystallized with either α-ketoglutarate or pyridoxamine 5'-phosphate and glutamate further define the molecular mechanisms underlying recognition of keto acid and amino acid substrates. Furthermore, cysteine was identified as an inhibitor of PAT from A. thaliana and Antirrhinum majus plants as well as the bacterium Chlorobium tepidum, uncovering a potential new effector of PAT.
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Affiliation(s)
- Cynthia K Holland
- Department of Biology, Washington University in St Louis, St Louis, MO, 63130, USA
| | - Daniel A Berkovich
- Department of Biology, Washington University in St Louis, St Louis, MO, 63130, USA
| | - Madeleine L Kohn
- Department of Biology, Washington University in St Louis, St Louis, MO, 63130, USA
| | - Hiroshi Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Joseph M Jez
- Department of Biology, Washington University in St Louis, St Louis, MO, 63130, USA
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von Born P, Bernardo-Faura M, Rubio-Somoza I. An artificial miRNA system reveals that relative contribution of translational inhibition to miRNA-mediated regulation depends on environmental and developmental factors in Arabidopsis thaliana. PLoS One 2018; 13:e0192984. [PMID: 29451902 PMCID: PMC5815599 DOI: 10.1371/journal.pone.0192984] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 02/01/2018] [Indexed: 11/24/2022] Open
Abstract
Development and fitness of any organism rely on properly controlled gene expression. This is especially true for plants, as their development is determined by both internal and external cues. MicroRNAs (miRNAs) are embedded in the genetic cascades that integrate and translate those cues into developmental programs. miRNAs negatively regulate their target genes mainly post-transcriptionally through two co-existing mechanisms; mRNA cleavage and translational inhibition. Despite our increasing knowledge about the genetic and biochemical processes involved in those concurrent mechanisms, little is known about their relative contributions to the overall miRNA-mediated regulation. Here we show that co-existence of cleavage and translational inhibition is dependent on growth temperature and developmental stage. We found that efficiency of an artificial miRNA-mediated (amiRNA) gene silencing declines with age during vegetative development in a temperature-dependent manner. That decline is mainly due to a reduction on the contribution from translational inhibition. Both, temperature and developmental stage were also found to affect mature amiRNA accumulation and the expression patterns of the core players involved in miRNA biogenesis and action. Therefore, that suggests that each miRNA family specifically regulates their respective targets, while temperature and growth might influence the performance of miRNA-dependent regulation in a more general way.
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Affiliation(s)
- Patrick von Born
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | | | - Ignacio Rubio-Somoza
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
- Molecular Reprogramming and Evolution Laboratory. Centre for Research in Agricultural Genomics, Barcelona, Spain
- * E-mail:
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Abstract
Developmental genetic studies of Antirrhinum majus demonstrated that two transcription factors from the MYB gene family, RADIALIS (RAD) and DIVIRICATA (DIV), interact through antagonism to regulate floral dorsoventral asymmetry. Interestingly, similar antagonistic interaction found among proteins of FSM1 (RAD-like) and MYBI (DIV-like) in Solanum lycopersicum is involved in fruit development. Here, we report the reconstruction of the phylogeny of I-box-like and R-R-type clades, where RAD- and DIV-like genes belong, respectively. We also examined the homology of these antagonistic MYB proteins using these phylogenies. The results show that there are likely three paralogs of RAD-/I-box-like genes, RAD1, RAD2, and RAD3, which originated in the common ancestor of the core eudicots. In contrast, R-R-type sequences fall into two major clades, RR1 and RR2, the result of gene duplication in the common ancestor of both monocots and dicots. RR1 was divided into clades RR1A, RR1B, and RR1C, while RR2 was divided into clades RR2A/DIV1, RR2B/DIV2, and RR2C/DIV3. We demonstrate that among similar antagonistic interactions in An. Majus and So. lycopersicum, RAD-like genes originate from the RAD2 clade, while DIV-like genes originate from distantly related paralogs of the R-R-type lineage. The phylogenetic analyses of these two MYB clades lay the foundation for future comparative studies including testing the evolution of the antagonistic relationship of proteins.
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Affiliation(s)
- Ao Gao
- Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284, USA.
| | - Jingbo Zhang
- Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284, USA.
| | - Wenheng Zhang
- Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284, USA.
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31
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Abstract
Autophagy is a degradation process in which cells break down and recycle their cytoplasmic contents when subjected to environmental stress or during cellular remodeling. The Arabidopsis thaliana SnRK1 complex is a protein kinase that senses changes in energy levels and triggers downstream responses to enable survival. Its mammalian ortholog, AMPK, and yeast ortholog, Snf-1, activate autophagy in response to low energy conditions. We therefore hypothesized that SnRK1 may play a role in the regulation of autophagy in response to nutrient or energy deficiency in Arabidopsis. To test this hypothesis, we determined the effect of overexpression or knockout of the SnRK1 catalytic subunit KIN10 on autophagy activation by abiotic stresses, including nutrient deficiency, salt, osmotic, oxidative, and ER stress. While wild-type plants had low basal autophagy activity in control conditions, KIN10 overexpression lines had increased autophagy under these conditions, indicating activation of autophagy by SnRK1. A kin10 mutant had a basal level of autophagy under control conditions similar to wild-type plants, but activation of autophagy by most abiotic stresses was blocked, indicating that SnRK1 is required for autophagy induction by a wide variety of stress conditions. In mammals, TOR is a negative regulator of autophagy, and AMPK acts to activate autophagy both upstream of TOR, by inhibiting its activity, and in a parallel pathway. Inhibition of Arabidopsis TOR leads to activation of autophagy; inhibition of SnRK1 did not block this activation. Furthermore, an increase in SnRK1 activity was unable to induce autophagy when TOR was also activated. These results demonstrate that SnRK1 acts upstream of TOR in the activation of autophagy in Arabidopsis.
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Affiliation(s)
- Junmarie Soto-Burgos
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Diane C. Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
- Plant Sciences Institute, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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32
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Kenesi E, Carbonell A, Lózsa R, Vértessy B, Lakatos L. A viral suppressor of RNA silencing inhibits ARGONAUTE 1 function by precluding target RNA binding to pre-assembled RISC. Nucleic Acids Res 2017; 45:7736-7750. [PMID: 28499009 PMCID: PMC5737661 DOI: 10.1093/nar/gkx379] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 04/20/2017] [Accepted: 04/24/2017] [Indexed: 11/23/2022] Open
Abstract
In most eukaryotes, RNA silencing is an adaptive immune system regulating key biological processes including antiviral defense. To evade this response, viruses of plants, worms and insects have evolved viral suppressors of RNA silencing proteins (VSRs). Various VSRs, such as P1 from Sweet potato mild mottle virus (SPMMV), inhibit the activity of RNA-induced silencing complexes (RISCs) including an ARGONAUTE (AGO) protein loaded with a small RNA. However, the specific mechanisms explaining this class of inhibition are unknown. Here, we show that SPMMV P1 interacts with AGO1 and AGO2 from Arabidopsis thaliana, but solely interferes with AGO1 function. Moreover, a mutational analysis of a newly identified zinc finger domain in P1 revealed that this domain could represent an effector domain as it is required for P1 suppressor activity but not for AGO1 binding. Finally, a comparative analysis of the target RNA binding capacity of AGO1 in the presence of wild-type or suppressor-defective P1 forms revealed that P1 blocks target RNA binding to AGO1. Our results describe the negative regulation of RISC, the small RNA containing molecular machine.
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Affiliation(s)
- Erzsébet Kenesi
- Department of Dermatology and Allergology, University of Szeged, Szeged H-6720, Hungary
| | - Alberto Carbonell
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), Valencia 46022, Spain
| | - Rita Lózsa
- Department of Physics of Complex Systems, Eötvös Loránd University, Budapest H-1116, Hungary
| | - Beáta Vértessy
- Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest H-1114, Hungary
- Institutes of Enzymology and Organic Chemistry, RCNS, Hungarian Academy of Sciences, Budapest H-1114, Hungary
| | - Lóránt Lakatos
- Department of Dermatology and Allergology, University of Szeged, Szeged H-6720, Hungary
- MTA-SZTE Dermatological Research Group
- Department of Pharmacognosy, University of Szeged, Szeged H-6720, Hungary
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Rissel D, Heym PP, Peiter E. A yeast growth assay to characterize plant poly(ADP-ribose) polymerase (PARP) proteins and inhibitors. Anal Biochem 2017; 527:20-23. [PMID: 28408182 DOI: 10.1016/j.ab.2017.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 04/03/2017] [Accepted: 04/08/2017] [Indexed: 12/23/2022]
Abstract
Poly(ADP-ribose) polymerases (PARPs) have been implicated in responses of plants to DNA damage and numerous stresses, whereby the mechanistic basis of the interference is often unclear. Therefore, the identification of specific inhibitors and potential interactors of plant PARPs is desirable. For this purpose, we established an assay based on heterologous expression of PARP genes from the model plant Arabidopsis thaliana in yeast. Expression of AtPARPs caused an inhibition of yeast growth to different extent, which was alleviated by inhibitors targeted at human PARPs. This assay provides a fast and simple means to identify target proteins and pharmacological inhibitors of AtPARP1.
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Affiliation(s)
- Dagmar Rissel
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany; Agrochemisches Institut Piesteritz e.V., 06886 Lutherstadt Wittenberg, Germany
| | | | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany; Agrochemisches Institut Piesteritz e.V., 06886 Lutherstadt Wittenberg, Germany.
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Ye Y, Zhou L, Liu X, Liu H, Li D, Cao M, Chen H, Xu L, Zhu JK, Zhao Y. A Novel Chemical Inhibitor of ABA Signaling Targets All ABA Receptors. Plant Physiol 2017; 173:2356-2369. [PMID: 28193765 PMCID: PMC5373061 DOI: 10.1104/pp.16.01862] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/10/2017] [Indexed: 05/03/2023]
Abstract
Abscisic acid (ABA), the most important stress-induced phytohormone, regulates seed dormancy, germination, plant senescence, and the abiotic stress response. ABA signaling is repressed by group A type 2C protein phosphatases (PP2Cs), and then ABA binds to its receptor of the ACTIN RESISTANCE1 (PYR1), PYR1-LIKE (PYL), and REGULATORY COMPONENTS OF ABA RECEPTORS (RCAR) family, which, in turn, inhibits PP2Cs and activates downstream ABA signaling. The agonist/antagonist of ABA receptors have the potential to reveal the ABA signaling machinery and to become lead compounds for agrochemicals; however, until now, no broad-spectrum antagonists of ABA receptors blocking all PYR/PYL-PP2C interactions have been identified. Here, using chemical genetics screenings, we identified ABA ANTAGONIST1 (AA1), the first broad-spectrum antagonist of ABA receptors in Arabidopsis (Arabidopsis thaliana). Physiological analyses revealed that AA1 is sufficiently active to block ABA signaling. AA1 interfered with all the PYR/PYL-HAB1 interactions, and the diminished PYR/PYL-HAB1 interactions, in turn, restored the activity of HAB1. AA1 binds to all 13 members. Molecular dockings, the non-AA1-bound PYL2 variant, and competitive binding assays demonstrated that AA1 enters into the ligand-binding pocket of PYL2. Using AA1, we tested the genetic relationships of ABA receptors with other core components of ABA signaling, demonstrating that AA1 is a powerful tool with which to sidestep this genetic redundancy of PYR/PYLs. In addition, the application of AA1 delays leaf senescence. Thus, our study developed an efficient broad-spectrum antagonist of ABA receptors and demonstrated that plant senescence can be chemically controlled through AA1, with a simple and easy-to-synthesize structure, allowing its availability and utility as a chemical probe synthesized in large quantities, indicating its potential application in agriculture.
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Affiliation(s)
- Yajin Ye
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Lijuan Zhou
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Xue Liu
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Hao Liu
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Deqiang Li
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Minjie Cao
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Haifeng Chen
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Lin Xu
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.)
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.)
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Jian-Kang Zhu
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China;
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.);
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.);
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
| | - Yang Zhao
- Institute of Plant Physiology and Ecology (Y.-J.Y., L.-J.Z., D.-Q.L., L.X., Y.Z.) and Shanghai Center for Plant Stress Biology (X.L., M.-J.C., J.-K.Z.), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China;
- University of the Chinese Academy of Sciences, Beijing 100000, China (Y.-J.Y., L.-J.Z., D.-Q.L.);
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China (Y.Z.);
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); and
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200032, China (X.L., H.-F.C.)
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35
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Abstract
Cell cycle regulation is fundamental to growth and development, and Cyclin-Dependent Kinase Inhibitors (CKIs) are major negative regulators of the cell cycle. Plant genomes encode substantially more CKIs than metazoan or fungal genomes. Plant CKIs fall into 2 distinct families, KIP-RELATED PROTEINS (KRPs) and SIAMESE-RELATED proteins (SMRs). SMRs can inhibit both S-phase and M-phase CDK complexes in vitro and are transcribed throughout the cell cycle, yet SMRs do not inhibit DNA replication in vivo. This suggests that SMRs must be activated post transcriptionally after the start of S-phase, but the mechanism of this hypothesized activation is unknown. Recent work indicates that even distantly related SMRs have the same biochemical function, and that differential transcriptional regulation likely maintains their distinct roles in integrating various environmental and developmental signals with the cell cycle.
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Affiliation(s)
- Narender Kumar
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - John C. Larkin
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
- CONTACT John C. Larkin Department of Biological Sciences, Louisiana State University, 202 Life Sciences, Baton Rouge, LA 70803, USA
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Sasaki T, Tsuchiya Y, Ariyoshi M, Ryan PR, Yamamoto Y. A chimeric protein of aluminum-activated malate transporter generated from wheat and Arabidopsis shows enhanced response to trivalent cations. Biochim Biophys Acta 2016; 1858:1427-35. [PMID: 27039280 DOI: 10.1016/j.bbamem.2016.03.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 03/16/2016] [Accepted: 03/29/2016] [Indexed: 11/19/2022]
Abstract
TaALMT1 from wheat (Triticum aestivum) and AtALMT1 from Arabidopsis thaliana encode aluminum (Al)-activated malate transporters, which confer acid-soil tolerance by releasing malate from roots. Chimeric proteins from TaALMT1 and AtALMT1 (Ta::At, At::Ta) were previously analyzed in Xenopus laevis oocytes. Those studies showed that Al could activate malate efflux from the Ta::At chimera but not from At::Ta. Here, functions of TaALMT1, AtALMT1 and the chimeric protein Ta::At were compared in cultured tobacco BY-2 cells. We focused on the sensitivity and specificity of their activation by trivalent cations. The activation of malate efflux by Al was at least two-fold greater in the chimera than the native proteins. All proteins were also activated by lanthanides (erbium, ytterbium, gadolinium, and lanthanum), but the chimera again released more malate than TaALMT1 or AtALMT1. In Xenopus oocytes, Al, ytterbium, and erbium activated inward currents from the native TaALMT1 and the chimeric protein, but gadolinium only activated currents from the chimera. Lanthanum inhibited currents from both proteins. These results demonstrated that function of the chimera protein was altered compared to the native proteins and was more responsive to a range of trivalent cations when expressed in plant cells.
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Affiliation(s)
- Takayuki Sasaki
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Okayama 710-0046, Japan.
| | - Yoshiyuki Tsuchiya
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Okayama 710-0046, Japan
| | - Michiyo Ariyoshi
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Okayama 710-0046, Japan
| | - Peter R Ryan
- CSIRO Agriculture, GPO Box 1600, Canberra, ACT, 2601, Australia
| | - Yoko Yamamoto
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Okayama 710-0046, Japan
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37
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Krasnoperova EE, Isayenkov SV, Yemets AI, Blume YB. [Not Available]. Tsitol Genet 2016; 50:3-10. [PMID: 30480412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
It was shown phenotypic changes in the root system of seedlings Arabidopsis thaliana in transgenic lines with overexpression and suppressed gene expression of serine-threonine protein kinase KIN10 in conditions of energy shortage and under normal conditions. The normal growth and development of KIN10 overexpressing plants with in energy deficiency conditions were detected. The significant inhibition of the plant development under normal conditions for these plant lines was obsereved. The levels of KIN10 gene expression under normal conditions in different organs A. thaliana, particularly in the roots, stems, leaves and flowers were analyzed. The highest level expression of the gene was fixed in the leaves.
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38
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Perrineau F, Wimalasekera R, Effendi Y, Scherer GFE. Inhibition of auxin transport and auxin signaling and treatment with far red light induces root coiling in the phospholipase-A mutant ppla-I-1. Significance for surface penetration? J Plant Physiol 2016; 196-197:53-9. [PMID: 27058428 DOI: 10.1016/j.jplph.2016.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/15/2016] [Accepted: 03/18/2016] [Indexed: 05/10/2023]
Abstract
When grown on a non-penetretable at a surface angle of 45°, Arabidopsis roots form wave-like structures and, in wild type rarely, but in certain mutants the tip root even may form circles. These circles are called coils. The formation of coils depends on the complex interaction of circumnutation, gravitropism and negative thigmotropism where - at least - gravitropism is intimately linked to auxin transport and signaling. The knockout mutant of patatin-related phospholipase-AI-1 (pplaI-1) is an auxin-signaling mutant which forms moderately increased numbers of coils on tilted agar plates. We tested the effects of the auxin efflux transport inhibitor NPA (1-naphthylphtalamic acid) and of the influx transport inhibitor 1-NOA (1-naphthoxyacetic acid) which both further increased root coil formation. The pPLAI-1 inhibitors HELSS (haloenol lactone suicide substrate=E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one) and ETYA (eicosatetraynoic acid) which are auxin signaling inhibitors also increased coil formation. In addition, far red light treatment increased coil formation. The results point out that a disturbance of auxin transport and signaling is one potential cause for root coils. As we show that the mutant pplaI-1 penetrates horizontal agar plates better than wild type plants root movements may help penetrating the soil.
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Affiliation(s)
- F Perrineau
- Leibniz Universität Hannover, Institut für Gartenbauliche Produktionssysteme, Abt. Molekulare Ertragsphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany; Universität Hamburg Fakultät für Mathematik, Informatik und Naturwissenschaften, Biologie, Biozentrum Klein Flottbek, Ohnhorststr. 18, 22609 Hamburg, Germany.
| | - R Wimalasekera
- Leibniz Universität Hannover, Institut für Gartenbauliche Produktionssysteme, Abt. Molekulare Ertragsphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany.
| | - Y Effendi
- Leibniz Universität Hannover, Institut für Gartenbauliche Produktionssysteme, Abt. Molekulare Ertragsphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany; Al Azhar Indonesia University, Department of Biology, Sisingamangaraja, 12110 Jakarta, Indonesia.
| | - G F E Scherer
- Leibniz Universität Hannover, Institut für Gartenbauliche Produktionssysteme, Abt. Molekulare Ertragsphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany.
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Hölscher C, Lutterbey MC, Lansing H, Meyer T, Fischer K, von Schaewen A. Defects in Peroxisomal 6-Phosphogluconate Dehydrogenase Isoform PGD2 Prevent Gametophytic Interaction in Arabidopsis thaliana. Plant Physiol 2016; 171:192-205. [PMID: 26941195 PMCID: PMC4854672 DOI: 10.1104/pp.15.01301] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 03/02/2016] [Indexed: 05/21/2023]
Abstract
We studied the localization of 6-phosphogluconate dehydrogenase (PGD) isoforms of Arabidopsis (Arabidopsis thaliana). Similar polypeptide lengths of PGD1, PGD2, and PGD3 obscured which isoform may represent the cytosolic and/or plastidic enzyme plus whether PGD2 with a peroxisomal targeting motif also might target plastids. Reporter-fusion analyses in protoplasts revealed that, with a free N terminus, PGD1 and PGD3 accumulate in the cytosol and chloroplasts, whereas PGD2 remains in the cytosol. Mutagenesis of a conserved second ATG enhanced the plastidic localization of PGD1 and PGD3 but not PGD2. Amino-terminal deletions of PGD2 fusions with a free C terminus resulted in peroxisomal import after dimerization, and PGD2 could be immunodetected in purified peroxisomes. Repeated selfing of pgd2 transfer (T-)DNA alleles yielded no homozygous mutants, although siliques and seeds of heterozygous plants developed normally. Detailed analyses of the C-terminally truncated PGD2-1 protein showed that peroxisomal import and catalytic activity are abolished. Reciprocal backcrosses of pgd2-1 suggested that missing PGD activity in peroxisomes primarily affects the male gametophyte. Tetrad analyses in the quartet1-2 background revealed that pgd2-1 pollen is vital and in vitro germination normal, but pollen tube growth inside stylar tissues appeared less directed. Mutual gametophytic sterility was overcome by complementation with a genomic construct but not with a version lacking the first ATG. These analyses showed that peroxisomal PGD2 activity is required for guided growth of the male gametophytes and pollen tube-ovule interaction. Our report finally demonstrates an essential role of oxidative pentose-phosphate pathway reactions in peroxisomes, likely needed to sustain critical levels of nitric oxide and/or jasmonic acid, whose biosynthesis both depend on NADPH provision.
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Affiliation(s)
- Christian Hölscher
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Marie-Christin Lutterbey
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Hannes Lansing
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Tanja Meyer
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Kerstin Fischer
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Antje von Schaewen
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
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Adhikari ND, Bates PD, Browse J. WRINKLED1 Rescues Feedback Inhibition of Fatty Acid Synthesis in Hydroxylase-Expressing Seeds. Plant Physiol 2016; 171:179-91. [PMID: 27208047 PMCID: PMC4854691 DOI: 10.1104/pp.15.01906] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 03/28/2016] [Indexed: 05/18/2023]
Abstract
Previous attempts at engineering Arabidopsis (Arabidopsis thaliana) to produce seed oils containing hydroxy fatty acids (HFA) have resulted in low yields of HFA compared with the native castor (Ricinus communis) plant and caused undesirable effects, including reduced total oil content. Recent studies have led to an understanding of problems involved in the accumulation of HFA in oils of transgenic plants, which include metabolic bottlenecks and a decrease in the rate of fatty acid synthesis. Focusing on engineering the triacylglycerol assembly mechanisms led to modest increases in the HFA content of seed oil, but much room for improvement still remains. We hypothesized that engineering fatty acid synthesis in the plastids to increase flux would facilitate enhanced total incorporation of fatty acids, including HFA, into seed oil. The transcription factor WRINKLED1 (WRI1) positively regulates the expression of genes involved in fatty acid synthesis and controls seed oil levels. We overexpressed Arabidopsis WRI1 in seeds of a transgenic line expressing the castor fatty acid hydroxylase. The proportion of HFA in the oil, the total HFA per seed, and the total oil content of seeds increased to an average of 20.9%, 1.26 µg, and 32.2%, respectively, across five independent lines, compared with 17.6%, 0.83 µg, and 27.9%, respectively, for isogenic segregants. WRI1 and WRI1-regulated genes involved in fatty acid synthesis were up-regulated, providing for a corresponding increase in the rate of fatty acid synthesis.
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Affiliation(s)
- Neil D Adhikari
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340 (N.D.A., J.B.); andDepartment of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406-0001 (P.D.B.)
| | - Philip D Bates
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340 (N.D.A., J.B.); andDepartment of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406-0001 (P.D.B.)
| | - John Browse
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340 (N.D.A., J.B.); andDepartment of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406-0001 (P.D.B.)
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Takemiya A, Doi A, Yoshida S, Okajima K, Tokutomi S, Shimazaki KI. Reconstitution of an Initial Step of Phototropin Signaling in Stomatal Guard Cells. Plant Cell Physiol 2016; 57:152-159. [PMID: 26707730 DOI: 10.1093/pcp/pcv180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/10/2015] [Indexed: 06/05/2023]
Abstract
Phototropins are light-activated receptor kinases that mediate a wide range of blue light responses responsible for the optimization of photosynthesis. Despite the physiological importance of phototropins, it is still unclear how they transduce light signals into physiological responses. Here, we succeeded in reproducing a primary step of phototropin signaling in vitro using a physiological substrate of phototropin, the BLUS1 (BLUE LIGHT SIGNALING1) kinase of guard cells. When PHOT1 and BLUS1 were expressed in Escherichia coli and the resulting recombinant proteins were incubated with ATP, white and blue light induced phosphorylation of BLUS1 but red light and darkness did not. Site-directed mutagenesis of PHOT1 and BLUS1 revealed that the phosphorylation was catalyzed by phot1 kinase. Similar to stomatal blue light responses, the BLUS1 phosphorylation depended on the fluence rate of blue light and was inhibited by protein kinase inhibitors, K-252a and staurosporine. In contrast to the result in vivo, BLUS1 was not dephosphorylated in vitro, suggesting the involvement of a protein phosphatase in the response in vivo. phot1 with a C-terminal kinase domain but devoid of the N-terminal domain, constitutively phosphorylated BLUS1 without blue light, indicating that the N-terminal domain has an autoinhibitory action and prevents substrate phosphorylation. The results provide the first reconstitution of a primary step of phototropin signaling and a clue for understanding the molecular nature of this process.
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Affiliation(s)
- Atsushi Takemiya
- Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan
| | - Ayaka Doi
- Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan
| | - Sayumi Yoshida
- Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan
| | - Koji Okajima
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-851 Japan Present address: Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Kanagawa, 223-8522 Japan.
| | - Satoru Tokutomi
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-851 Japan
| | - Ken-Ichiro Shimazaki
- Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan
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Su T, Wolf S, Han M, Zhao H, Wei H, Greiner S, Rausch T. Reassessment of an Arabidopsis cell wall invertase inhibitor AtCIF1 reveals its role in seed germination and early seedling growth. Plant Mol Biol 2016; 90:137-55. [PMID: 26546341 DOI: 10.1007/s11103-015-0402-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/30/2015] [Indexed: 05/19/2023]
Abstract
In higher plants, cell wall invertase (CWI) and vacuolar invertase (VI) are recognized as essential players in sugar metabolism and sugar signaling, thereby affecting source-sink interactions, plant development and responses to environmental cues. CWI and VI expression levels are transcriptionally controlled; however, both enzymes are also subject to posttranslational control by invertase inhibitor proteins. The physiological significances of inhibitor proteins during seed germination and early seedling development are not yet fully understood. Here, we demonstrate that the inhibitor isoform AtCIF1 impacted on seed germination and early seedling growth in Arabidopsis. The primary target of AtCIF1 was shown to be localized to the apoplast after expressing an AtCIF1 YFP-fusion construct in tobacco epidermis and transgenic Arabidopsis root. The analysis of expression patterns showed that AtCWI1 was co-expressed spatiotemporally with AtCIF1 within the early germinating seeds. Seed germination was observed to be accelerated independently of exogenous abscisic acid (ABA) in the AtCIF1 loss-of-function mutant cif1-1. This effect coincided with a drastic increase of CWI activity in cif1-1 mutant seeds by 24 h after the onset of germination, both in vitro and in planta. Accordingly, quantification of sugar content showed that hexose levels were significantly boosted in germinating seeds of the cif1-1 mutant. Further investigation of AtCIF1 overexpressors in Arabidopsis revealed a markedly suppressed CWI activity as well as delayed seed germination. Thus, we conclude that the posttranslational modulation of CWI activity by AtCIF1 helps to orchestrate seed germination and early seedling growth via fine-tuning sucrose hydrolysis and, possibly, sugar signaling.
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Affiliation(s)
- Tao Su
- Plant Molecular Physiology, Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, Heidelberg, 69120, Germany.
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
| | - Sebastian Wolf
- Plant Molecular Physiology, Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, Heidelberg, 69120, Germany.
| | - Mei Han
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
| | - Hongbo Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Hongbin Wei
- Plant Molecular Physiology, Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, Heidelberg, 69120, Germany.
| | - Steffen Greiner
- Plant Molecular Physiology, Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, Heidelberg, 69120, Germany.
| | - Thomas Rausch
- Plant Molecular Physiology, Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 360, Heidelberg, 69120, Germany.
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Kriegel A, Andrés Z, Medzihradszky A, Krüger F, Scholl S, Delang S, Patir-Nebioglu MG, Gute G, Yang H, Murphy AS, Peer WA, Pfeiffer A, Krebs M, Lohmann JU, Schumacher K. Job Sharing in the Endomembrane System: Vacuolar Acidification Requires the Combined Activity of V-ATPase and V-PPase. Plant Cell 2015; 27:3383-96. [PMID: 26589552 PMCID: PMC4707456 DOI: 10.1105/tpc.15.00733] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/21/2015] [Accepted: 11/05/2015] [Indexed: 05/19/2023]
Abstract
The presence of a large central vacuole is one of the hallmarks of a prototypical plant cell, and the multiple functions of this compartment require massive fluxes of molecules across its limiting membrane, the tonoplast. Transport is assumed to be energized by the membrane potential and the proton gradient established by the combined activity of two proton pumps, the vacuolar H(+)-pyrophosphatase (V-PPase) and the vacuolar H(+)-ATPase (V-ATPase). Exactly how labor is divided between these two enzymes has remained elusive. Here, we provide evidence using gain- and loss-of-function approaches that lack of the V-ATPase cannot be compensated for by increased V-PPase activity. Moreover, we show that increased V-ATPase activity during cold acclimation requires the presence of the V-PPase. Most importantly, we demonstrate that a mutant lacking both of these proton pumps is conditionally viable and retains significant vacuolar acidification, pointing to a so far undetected contribution of the trans-Golgi network/early endosome-localized V-ATPase to vacuolar pH.
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Affiliation(s)
- Anne Kriegel
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Zaida Andrés
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Anna Medzihradszky
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Falco Krüger
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Stefan Scholl
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Simon Delang
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - M Görkem Patir-Nebioglu
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Gezahegn Gute
- Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742
| | - Haibing Yang
- Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907
| | - Angus S Murphy
- Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742
| | - Wendy Ann Peer
- Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 Environmental Science and Technology, University of Maryland, College Park, Maryland 20742
| | - Anne Pfeiffer
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Melanie Krebs
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Jan U Lohmann
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Karin Schumacher
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
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Kakei Y, Yamazaki C, Suzuki M, Nakamura A, Sato A, Ishida Y, Kikuchi R, Higashi S, Kokudo Y, Ishii T, Soeno K, Shimada Y. Small-molecule auxin inhibitors that target YUCCA are powerful tools for studying auxin function. Plant J 2015; 84:827-37. [PMID: 26402640 DOI: 10.1111/tpj.13032] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 09/07/2015] [Accepted: 09/11/2015] [Indexed: 05/12/2023]
Abstract
Auxin is essential for plant growth and development, this makes it difficult to study the biological function of auxin using auxin-deficient mutants. Chemical genetics have the potential to overcome this difficulty by temporally reducing the auxin function using inhibitors. Recently, the indole-3-pyruvate (IPyA) pathway was suggested to be a major biosynthesis pathway in Arabidopsis thaliana L. for indole-3-acetic acid (IAA), the most common member of the auxin family. In this pathway, YUCCA, a flavin-containing monooxygenase (YUC), catalyzes the last step of conversion from IPyA to IAA. In this study, we screened effective inhibitors, 4-biphenylboronic acid (BBo) and 4-phenoxyphenylboronic acid (PPBo), which target YUC. These compounds inhibited the activity of recombinant YUC in vitro, reduced endogenous IAA content, and inhibited primary root elongation and lateral root formation in wild-type Arabidopsis seedlings. Co-treatment with IAA reduced the inhibitory effects. Kinetic studies of BBo and PPBo showed that they are competitive inhibitors of the substrate IPyA. Inhibition constants (Ki ) of BBo and PPBo were 67 and 56 nm, respectively. In addition, PPBo did not interfere with the auxin response of auxin-marker genes when it was co-treated with IAA, suggesting that PPBo is not an inhibitor of auxin sensing or signaling. We propose that these compounds are a class of auxin biosynthesis inhibitors that target YUC. These small molecules are powerful tools for the chemical genetic analysis of auxin function.
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Affiliation(s)
- Yusuke Kakei
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
| | - Chiaki Yamazaki
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
| | - Masashi Suzuki
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
| | - Ayako Nakamura
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
| | - Akiko Sato
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
| | - Yosuke Ishida
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
| | - Rie Kikuchi
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
| | - Shouichi Higashi
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, 236-0027, Japan
| | - Yumiko Kokudo
- National Agriculture and Food Research Organization (NARO), Western Region Agricultural Research Center (WARC), Senyu, Zentsuji, Kagawa, 765-8508, Japan
| | - Takahiro Ishii
- National Agriculture and Food Research Organization (NARO), Western Region Agricultural Research Center (WARC), Senyu, Zentsuji, Kagawa, 765-8508, Japan
| | - Kazuo Soeno
- National Agriculture and Food Research Organization (NARO), Western Region Agricultural Research Center (WARC), Senyu, Zentsuji, Kagawa, 765-8508, Japan
| | - Yukihisa Shimada
- Kihara Institute for Biological Research, Yokohama City University, Maiokacho 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan
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Hahn HG, Choi JS, Lim HK, Lee KI, Hwang IT. Triazolyl phenyl disulfides: 8-Amino-7-oxononanoate synthase inhibitors as potential herbicides. Pestic Biochem Physiol 2015; 125:78-83. [PMID: 26615154 DOI: 10.1016/j.pestbp.2015.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/12/2015] [Accepted: 05/12/2015] [Indexed: 06/05/2023]
Abstract
The chemical validation of a potential herbicide target was investigated with 8-amino-7-oxononanoate synthase (AONS, also known as 7-keto-8-aminopelargonate synthase, KAPAS) and triazolyl phenyl disulfide derivatives in vitro and in vivo. AONS activity was completely inhibited by these synthesized compounds, with an IC50 of 48 to 592μM in vitro. Forty five-day old Arabidopsis thaliana plants were completely killed by representative compound KHG23844 {N-(2-fluorophenyl)-3-(phenyldisulphanyl)-1H-1,2,4-triazole-1-carboxamide} at the application rate of 250gha(-1) of foliar treatment in greenhouse conditions. Foliar application of 1000gha(-1) KHG23844 induced 2.3-fold higher l-alanine accumulation in the treated A. thaliana plants. Foliar supplement of 1mM biotin at 1 and 2days before KHG23844 application effectively recovered the growth inhibition of A. thaliana plant treated with KHG23844. The results strongly suggested that representative compound KHG23844 and its derivatives are potential AONS inhibitors.
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Affiliation(s)
- Hoh-Gyu Hahn
- Korea Institute of Science and Technology, 39-1, Wolsong-Gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea
| | - Jung-Sup Choi
- Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejon, 305-600, Republic of Korea
| | - Hee Kyung Lim
- Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejon, 305-600, Republic of Korea
| | - Kee-In Lee
- Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejon, 305-600, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, University of Science & Technology, 217 Gajungro, Yuseong-gu, Daejon 305-350, Republic of Korea
| | - In Taek Hwang
- Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejon, 305-600, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, University of Science & Technology, 217 Gajungro, Yuseong-gu, Daejon 305-350, Republic of Korea.
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Khokon MAR, Salam MA, Jammes F, Ye W, Hossain MA, Uraji M, Nakamura Y, Mori IC, Kwak JM, Murata Y. Two guard cell mitogen-activated protein kinases, MPK9 and MPK12, function in methyl jasmonate-induced stomatal closure in Arabidopsis thaliana. Plant Biol (Stuttg) 2015; 17:946-52. [PMID: 25703019 DOI: 10.1111/plb.12321] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/06/2015] [Indexed: 05/04/2023]
Abstract
Methyl jasmonate (MeJA) and abscisic acid (ABA) signalling cascades share several signalling components in guard cells. We previously showed that two guard cell-preferential mitogen-activated protein kinases (MAPKs), MPK9 and MPK12, positively regulate ABA signalling in Arabidopsis thaliana. In this study, we examined whether these two MAP kinases function in MeJA signalling using genetic mutants for MPK9 and MPK12 combined with a pharmacological approach. MeJA induced stomatal closure in mpk9-1 and mpk12-1 single mutants as well as wild-type plants, but not in mpk9-1 mpk12-1 double mutants. Consistently, the MAPKK inhibitor PD98059 inhibited the MeJA-induced stomatal closure in wild-type plants. MeJA elicited reactive oxygen species (ROS) production and cytosolic alkalisation in guard cells of the mpk9-1, mpk12-1 and mpk9-1 mpk12-1 mutants, as well in wild-type plants. Furthermore, MeJA triggered elevation of cytosolic Ca(2+) concentration ([Ca(2+)]cyt ) in the mpk9-1 mpk12-1 double mutant as well as wild-type plants. Activation of S-type anion channels by MeJA was impaired in mpk9-1 mpk12-1. Together, these results indicate that MPK9 and MPK12 function upstream of S-type anion channel activation and downstream of ROS production, cytosolic alkalisation and [Ca(2+)]cyt elevation in guard cell MeJA signalling, suggesting that MPK9 and MPK12 are key regulators mediating both ABA and MeJA signalling in guard cells.
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Affiliation(s)
- Md A R Khokon
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - M A Salam
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - F Jammes
- Department of Biology, Pomona College, Claremont, CA, USA
| | - W Ye
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - M A Hossain
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - M Uraji
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Y Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - I C Mori
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, Japan
| | - J M Kwak
- Department of New Biology, Center for Plant Aging Research, Institute for Basic Science, Daegu Kyungbuk Institute of Science and Technology, Daegu, Korea
| | - Y Murata
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
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47
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Ok SH, Cho JH, Oh SI, Choi MN, Ma JY, Shin JS, Kim KN. Calcineurin B-like 3 calcium sensor associates with and inhibits 5'-methylthioadenosine nucleosidase 2 in Arabidopsis. Plant Sci 2015; 238:228-40. [PMID: 26259190 DOI: 10.1016/j.plantsci.2015.06.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 06/16/2015] [Accepted: 06/16/2015] [Indexed: 05/04/2023]
Abstract
Calcineurin B-like (CBL) proteins constitute a unique family of calcium sensor relays in plants. It is well known that CBLs detect the calcium signals elicited by a variety of abiotic stresses and relay the information to a group of serine/threonine protein kinases called CBL-interacting protein kinases (CIPKs). In this study, we found that a few CBL members can also target another group of enzymes 5'-methylthioadenosine nucleosidases (MTANs), which are encoded by two genes in Arabidopsis, AtMTAN1 and AtMTAN2. In the yeast two-hybrid system, AtMTAN1 interacted with multiple CBL members such as CBL2, CBL3 and CBL6, whereas AtMTAN2 associated exclusively with CBL3. We further demonstrated that the CBL3-AtMTAN2 association occurs in a calcium-dependent manner, which results in a significant decrease in the enzyme activity of the AtMTAN2 protein. Taken together, these results clearly indicate that the CBL family can target at least two distinct groups of enzymes (CIPKs and MTANs), conferring an additional level of complexity on the CBL-mediated signaling networks. In addition, our finding also provides a novel molecular mechanism by which calcium signals are transduced to alter metabolite profiles in plants.
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Affiliation(s)
- Sung Han Ok
- Department of Molecular Biology, PERI, Sejong University, Seoul 143-747, Republic of Korea
| | - Joo Hyuk Cho
- Department of Molecular Biology, PERI, Sejong University, Seoul 143-747, Republic of Korea
| | - Seung-Ick Oh
- School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Mi Na Choi
- Department of Molecular Biology, PERI, Sejong University, Seoul 143-747, Republic of Korea
| | - Jae-Yeon Ma
- Department of Molecular Biology, PERI, Sejong University, Seoul 143-747, Republic of Korea
| | - Jeong-Sheop Shin
- School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Kyung-Nam Kim
- Department of Molecular Biology, PERI, Sejong University, Seoul 143-747, Republic of Korea.
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48
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Wang DW, Lin HY, Cao RJ, Ming ZZ, Chen T, Hao GF, Yang WC, Yang GF. Design, synthesis and herbicidal activity of novel quinazoline-2,4-diones as 4-hydroxyphenylpyruvate dioxygenase inhibitors. Pest Manag Sci 2015; 71:1122-32. [PMID: 25185782 DOI: 10.1002/ps.3894] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/23/2014] [Accepted: 08/23/2014] [Indexed: 05/24/2023]
Abstract
BACKGROUND 4-Hydroxyphenylpyruvate dioxygenase (HPPD) (EC 1.13.11.27) has been identified as one of the most promising target sites for herbicide discovery. To discover novel HPPD inhibitors with high herbicidal activity and improved crop selectivity, a series of novel triketone-containing quinazoline-2,4-dione derivatives possessing a variety of substituents at the N-1 position of the quinazoline-2,4-dione ring were designed and synthesised. RESULTS The results of in vitro tests and greenhouse experiments indicated that some analogues showed good HPPD inhibitory activity, with promising broad-spectrum herbicidal activity at a rate of 150 g AI ha(-1) . Most surprisingly, compound 11 h, 1-ethyl-6-(2-hydroxy-6-oxocyclohex-1-enecarbonyl)-3-(o-tolyl)quinazoline-2,4(1H,3H)-dione, showed the highest HPPD inhibition activity, with a Ki value of 0.005 μM, about 2 times more potent than mesotrione (Ki = 0.013 μM). Further greenhouse experiments indicated that compounds 11d and 11 h displayed strong and broad-spectrum post-emergent herbicidal activity even at a dosage as low as 37.5 g AI ha(-1) , which was superior to mesotrione. More importantly, compounds 11d and 11 h were safe for maize at a rate of 150 g AI ha(-1) , and compound 11d was safe for wheat as well. CONCLUSION The present work indicated that the triketone-containing quinazoline-2,4-dione motif could be a potential lead structure for further development of novel herbicides.
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Affiliation(s)
- Da-Wei Wang
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
| | - Hong-Yan Lin
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
| | - Run-Jie Cao
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
| | - Ze-Zhong Ming
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
| | - Tao Chen
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
| | - Ge-Fei Hao
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
| | - Wen-Chao Yang
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
| | - Guang-Fu Yang
- Key Laboratory of Pesticide and Chemical Biology, College of Chemistry, Central China Normal University, Wuhan, China
- Collaborative Innovation Centre of Chemical Science and Engineering, Tianjin, China
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49
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Horst RJ, Fujita H, Lee JS, Rychel AL, Garrick JM, Kawaguchi M, Peterson KM, Torii KU. Molecular Framework of a Regulatory Circuit Initiating Two-Dimensional Spatial Patterning of Stomatal Lineage. PLoS Genet 2015; 11:e1005374. [PMID: 26203655 PMCID: PMC4512730 DOI: 10.1371/journal.pgen.1005374] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 06/19/2015] [Indexed: 11/23/2022] Open
Abstract
Stomata, valves on the plant epidermis, are critical for plant growth and survival, and the presence of stomata impacts the global water and carbon cycle. Although transcription factors and cell-cell signaling components regulating stomatal development have been identified, it remains unclear as to how their regulatory interactions are translated into two-dimensional patterns of stomatal initial cells. Using molecular genetics, imaging, and mathematical simulation, we report a regulatory circuit that initiates the stomatal cell-lineage. The circuit includes a positive feedback loop constituting self-activation of SCREAMs that requires SPEECHLESS. This transcription factor module directly binds to the promoters and activates a secreted signal, EPIDERMAL PATTERNING FACTOR2, and the receptor modifier TOO MANY MOUTHS, while the receptor ERECTA lies outside of this module. This in turn inhibits SPCH, and hence SCRMs, thus constituting a negative feedback loop. Our mathematical model accurately predicts all known stomatal phenotypes with the inclusion of two additional components to the circuit: an EPF2-independent negative-feedback loop and a signal that lies outside of the SPCH•SCRM module. Our work reveals the intricate molecular framework governing self-organizing two-dimensional patterning in the plant epidermis.
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Affiliation(s)
- Robin J. Horst
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | | | - Jin Suk Lee
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Amanda L. Rychel
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Jacqueline M. Garrick
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | | | - Kylee M. Peterson
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Keiko U. Torii
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
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50
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Wang DW, Lin HY, Cao RJ, Chen T, Wu FX, Hao GF, Chen Q, Yang WC, Yang GF. Synthesis and Herbicidal Activity of Triketone-Quinoline Hybrids as Novel 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors. J Agric Food Chem 2015; 63:5587-5596. [PMID: 26006257 DOI: 10.1021/acs.jafc.5b01530] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
4-Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD) is one of the most important targets for herbicide discovery. In the search for new HPPD inhibitors with novel scaffolds, triketone-quinoline hybrids were designed and subsequently optimized on the basis of the structure-activity relationship (SAR) studies. Most of the synthesized compounds displayed potent inhibition of Arabidopsis thaliana HPPD (AtHPPD), and some of them exhibited broad-spectrum and promising herbicidal activity at the rate of 150 g ai/ha by postemergence application. Most promisingly, compound III-l, 3-hydroxy-2-(2-methoxy-7-(methylthio)quinoline-3-carbonyl)cyclohex-2-enone (Ki = 0.009 μM, AtHPPD), had broader spectrum of weed control than mesotrione. Furthermore, compound III-l was much safer to maize at the rate of 150 g ai/ha than mesotrione, demonstrating its great potential as herbicide for weed control in maize fields. Therefore, triketone-quinoline hybrids may serve as new lead structures for novel herbicide discovery.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Guang-Fu Yang
- ‡Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 30071, People's Republic of China
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