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Šmeringai J, Schrumpfová PP, Pernisová M. Cytokinins - regulators of de novo shoot organogenesis. FRONTIERS IN PLANT SCIENCE 2023; 14:1239133. [PMID: 37662179 PMCID: PMC10471832 DOI: 10.3389/fpls.2023.1239133] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/31/2023] [Indexed: 09/05/2023]
Abstract
Plants, unlike animals, possess a unique developmental plasticity, that allows them to adapt to changing environmental conditions. A fundamental aspect of this plasticity is their ability to undergo postembryonic de novo organogenesis. This requires the presence of regulators that trigger and mediate specific spatiotemporal changes in developmental programs. The phytohormone cytokinin has been known as a principal regulator of plant development for more than six decades. In de novo shoot organogenesis and in vitro shoot regeneration, cytokinins are the prime candidates for the signal that determines shoot identity. Both processes of de novo shoot apical meristem development are accompanied by changes in gene expression, cell fate reprogramming, and the switching-on of the shoot-specific homeodomain regulator, WUSCHEL. Current understanding about the role of cytokinins in the shoot regeneration will be discussed.
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Affiliation(s)
- Ján Šmeringai
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Petra Procházková Schrumpfová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Markéta Pernisová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czechia
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2
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Chen X, Kim SH, Rhee S, Witte CP. A plastid nucleoside kinase is involved in inosine salvage and control of purine nucleotide biosynthesis. THE PLANT CELL 2023; 35:510-528. [PMID: 36342213 PMCID: PMC9806653 DOI: 10.1093/plcell/koac320] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 11/02/2022] [Indexed: 05/19/2023]
Abstract
In nucleotide metabolism, nucleoside kinases recycle nucleosides into nucleotides-a process called nucleoside salvage. Nucleoside kinases for adenosine, uridine, and cytidine have been characterized from many organisms, but kinases for inosine and guanosine salvage are not yet known in eukaryotes and only a few such enzymes have been described from bacteria. Here we identified Arabidopsis thaliana PLASTID NUCLEOSIDE KINASE 1 (PNK1), an enzyme highly conserved in plants and green algae belonging to the Phosphofructokinase B family. We demonstrate that PNK1 from A. thaliana is located in plastids and catalyzes the phosphorylation of inosine, 5-aminoimidazole-4-carboxamide-1-β-d-ribose (AICA ribonucleoside), and uridine but not guanosine in vitro, and is involved in inosine salvage in vivo. PNK1 mutation leads to increased flux into purine nucleotide catabolism and, especially in the context of defective uridine degradation, to over-accumulation of uridine and UTP as well as growth depression. The data suggest that PNK1 is involved in feedback regulation of purine nucleotide biosynthesis and possibly also pyrimidine nucleotide biosynthesis. We additionally report that cold stress leads to accumulation of purine nucleotides, probably by inducing nucleotide biosynthesis, but that this adjustment of nucleotide homeostasis to environmental conditions is not controlled by PNK1.
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Affiliation(s)
- Xiaoguang Chen
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover 30419, Germany
| | - Sang-Hoon Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea
| | - Sangkee Rhee
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea
| | - Claus-Peter Witte
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover 30419, Germany
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3
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Yegutkin GG, Boison D. ATP and Adenosine Metabolism in Cancer: Exploitation for Therapeutic Gain. Pharmacol Rev 2022; 74:797-822. [PMID: 35738682 DOI: 10.1124/pharmrev.121.000528] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Adenosine is an evolutionary ancient metabolic regulator linking energy state to physiologic processes, including immunomodulation and cell proliferation. Tumors create an adenosine-rich immunosuppressive microenvironment through the increased release of ATP from dying and stressed cells and its ectoenzymatic conversion into adenosine. Therefore, the adenosine pathway becomes an important therapeutic target to improve the effectiveness of immune therapies. Prior research has focused largely on the two major ectonucleotidases, ectonucleoside triphosphate diphosphohydrolase 1/cluster of differentiation (CD)39 and ecto-5'-nucleotidase/CD73, which catalyze the breakdown of extracellular ATP into adenosine, and on the subsequent activation of different subtypes of adenosine receptors with mixed findings of antitumor and protumor effects. New findings, needed for more effective therapeutic approaches, require consideration of redundant pathways controlling intratumoral adenosine levels, including the alternative NAD-inactivating pathway through the CD38-ectonucleotide pyrophosphatase phosphodiesterase (ENPP)1-CD73 axis, the counteracting ATP-regenerating ectoenzymatic pathway, and cellular adenosine uptake and its phosphorylation by adenosine kinase. This review provides a holistic view of extracellular and intracellular adenosine metabolism as an integrated complex network and summarizes recent data on the underlying mechanisms through which adenosine and its precursors ATP and ADP control cancer immunosurveillance, tumor angiogenesis, lymphangiogenesis, cancer-associated thrombosis, blood flow, and tumor perfusion. Special attention is given to differences and commonalities in the purinome of different cancers, heterogeneity of the tumor microenvironment, subcellular compartmentalization of the adenosine system, and novel roles of purine-converting enzymes as targets for cancer therapy. SIGNIFICANCE STATEMENT: The discovery of the role of adenosine as immune checkpoint regulator in cancer has led to the development of novel therapeutic strategies targeting extracellular adenosine metabolism and signaling in multiple clinical trials and preclinical models. Here we identify major gaps in knowledge that need to be filled to improve the therapeutic gain from agents targeting key components of the adenosine metabolic network and, on this basis, provide a holistic view of the cancer purinome as a complex and integrated network.
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Affiliation(s)
- Gennady G Yegutkin
- MediCity Research Laboratory and InFLAMES Flagship, University of Turku, Turku, Finland (G.G.Y.); Department of Neurosurgery, Robert Wood Johnson and New Jersey Medical Schools, Rutgers University, Piscataway, New Jersey (D.B.); and Rutgers Brain Health Institute, Piscataway, New Jersey (D.B.)
| | - Detlev Boison
- MediCity Research Laboratory and InFLAMES Flagship, University of Turku, Turku, Finland (G.G.Y.); Department of Neurosurgery, Robert Wood Johnson and New Jersey Medical Schools, Rutgers University, Piscataway, New Jersey (D.B.); and Rutgers Brain Health Institute, Piscataway, New Jersey (D.B.)
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Kaźmierczak A, Kunikowska A, Doniak M, Kornaś A. Mechanism of kinetin-induced death of Vicia faba ssp. minor root cortex cells. Sci Rep 2021; 11:23746. [PMID: 34887458 PMCID: PMC8660813 DOI: 10.1038/s41598-021-03103-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 11/16/2021] [Indexed: 01/03/2023] Open
Abstract
Cell death (CD) may be induced by endogenous or exogenous factors and contributes to all the steps of plant development. This paper presents results related to the mechanism of CD regulation induced by kinetin (Kin) in the root cortex of Vicia faba ssp. minor. To explain the process, 6-(2-hydroxy-3-methylbenzylamino)purine (PI-55), adenine (Ad), 5'-amine-5'-deoxyadenosine (Ado) and N-(2-chloro-4-piridylo)-N'-phenylurea (CPPU) were applied to (i) block cytokinin receptors (CKs) and inhibit the activities of enzymes of CK metabolism, i.e., (ii) phosphoribosyltransferase, (iii) kinases, and (iv) oxidases, respectively. Moreover, ethylene glycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), lanthanum chloride (LaCl3), ruthenium red (RRed) and cyclosporine A (CS-A) were applied to (i) chelate extracellular calcium ions (Ca2+) as well as blocks of (ii) plasma-, (iii) endoplasmic reticulum- (ER) membrane Ca2+ ion channels and (iv) mitochondria- (MIT) Ca2+ ions release by permeability transition por (PTP), respectively. The measured physiological effectiveness of these factors was the number of living and dying cortex cells estimated with orange acridine (OA) and ethidium bromide (EB), the amounts of cytosolic Ca2+ ions with chlortetracycline (CTC) staining and the intensity of chromatin and Ca2+-CTC complex fluorescence, respectively. Moreover, the role of sorafenib, an inhibitor of RAF kinase, on the vitality of cortex cells and ethylene levels as well as the activities of RAF-like kinase and MEK2 with Syntide-2 and Mek2 as substrates were studied. The results clarified the previously presented suggestion that Kin is converted to appropriate ribotides (5'-monophosphate ribonucleotides), which cooperate with the ethylene and Ca2+ ion signalling pathways to transduce the signal of kinetin-programmed cell death (Kin-PCD). Based on the present and previously published results related to Kin-PCD, the crosstalk between ethylene and MAP kinase signalling, as well as inhibitors of CK receptors and enzymes of their metabolism, is proposed.
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Affiliation(s)
- Andrzej Kaźmierczak
- Department of Cytophysiology, Institute of Experimental Biology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Lodz, Poland.
| | - Anita Kunikowska
- Department of Cytophysiology, Institute of Experimental Biology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Lodz, Poland
| | - Magdalena Doniak
- Department of Cytophysiology, Institute of Experimental Biology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Lodz, Poland
| | - Andrzej Kornaś
- Institute of Biology, Pedagogical University of Krakow, Podchorążych 2, 30-084, Kraków, Poland
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Sun C, Li Z, Ning X, Xu W, Li Z. In vitro biosynthesis of ATP from adenosine and polyphosphate. BIORESOUR BIOPROCESS 2021; 8:117. [PMID: 38650279 PMCID: PMC10992290 DOI: 10.1186/s40643-021-00469-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/21/2021] [Indexed: 11/10/2022] Open
Abstract
Adenosine triphosphate (ATP) acts as a crucial energy currency in vivo, and it is a widely used energy and/or phosphate donor for enzyme-catalyzed reactions in vitro. In this study, we established an in vitro multi-enzyme cascade system for ATP production. Using adenosine and inorganic polyphosphate (polyP) as key substrates, we combined adenosine kinase and two functionally distinct polyphosphate kinases (PPKs) in a one-pot reaction to achieve chain-like ATP regeneration and production. Several sources of PPK were screened and characterized, and two suitable PPKs were selected to achieve high rates of ATP production. Among these, Sulfurovum lithotrophicum PPK (SlPPK) exhibited excellent activity over a wide pH range (pH 4.0-9.0) and synthesized ATP from ADP using short-chain polyP. Furthermore, it had a half-life > 155.6 h at 45 °C. After optimizing the reaction conditions, we finally carried out the coupling-catalyzed reaction with different initial adenosine concentrations of 10, 20, and 30 mM. The highest yields of ATP were 76.0, 70.5, and 61.3%, respectively.
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Affiliation(s)
- Chuanqi Sun
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Zonglin Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
| | - Xiao Ning
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Wentian Xu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Zhimin Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai, 200237, China.
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Demmler R, Fricke J, Dörner S, Gressler M, Hoffmeister D. S-Adenosyl-l-Methionine Salvage Impacts Psilocybin Formation in "Magic" Mushrooms. Chembiochem 2020; 21:1364-1371. [PMID: 31802575 PMCID: PMC7317531 DOI: 10.1002/cbic.201900649] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Indexed: 12/20/2022]
Abstract
Psychotropic Psilocybe mushrooms biosynthesize their principal natural product psilocybin in five steps, among them a phosphotransfer and two methyltransfer reactions, which consume one equivalent of 5'-adenosine triphosphate (ATP) and two equivalents of S-adenosyl-l-methionine (SAM). This short but co-substrate-intensive pathway requires nucleoside cofactor salvage to maintain high psilocybin production rates. We characterized the adenosine kinase (AdoK) and S-adenosyl-l-homocysteine (SAH) hydrolase (SahH) of Psilocybe cubensis. Both enzymes are directly or indirectly involved in regenerating SAM. qRT-PCR expression analysis revealed an induced expression of the genes in the fungal primordia and carpophores. A one-pot in vitro reaction with the N-methyltransferase PsiM of the psilocybin pathway demonstrates a concerted action with SahH to facilitate biosynthesis by removal of accumulating SAH.
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Affiliation(s)
- Richard Demmler
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Janis Fricke
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Sebastian Dörner
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Markus Gressler
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Dirk Hoffmeister
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
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Pradhan S, Babar MA, Bai G, Khan J, Shahi D, Avci M, Guo J, McBreen J, Asseng S, Gezan S, Baik BK, Blount A, Harrison S, Sapkota S, St Amand P, Kunwar S. Genetic dissection of heat-responsive physiological traits to improve adaptation and increase yield potential in soft winter wheat. BMC Genomics 2020; 21:315. [PMID: 32312234 PMCID: PMC7171738 DOI: 10.1186/s12864-020-6717-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 04/05/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Climate change, including higher temperatures (HT) has a detrimental impact on wheat productivity and modeling studies predict more frequent heat waves in the future. Wheat growth can be impaired by high daytime and nighttime temperature at any developmental stage, especially during the grain filling stage. Leaf chlorophyll content, leaf greenness, cell membrane thermostability, and canopy temperature have been proposed as candidate traits to improve crop adaptation and yield potential of wheat under HT. Nonetheless, a significant gap exists in knowledge of genetic backgrounds associated with these physiological traits. Identifying genetic loci associated with these traits can facilitate physiological breeding for increased yield potential under high temperature stress condition in wheat. RESULTS We conducted genome-wide association study (GWAS) on a 236 elite soft wheat association mapping panel using 27,466 high quality single nucleotide polymorphism markers. The panel was phenotyped for three years in two locations where heat shock was common. GWAS identified 500 significant marker-trait associations (MTAs) (p ≤ 9.99 × 10- 4). Ten MTAs with pleiotropic effects detected on chromosomes 1D, 2B, 3A, 3B, 6A, 7B, and 7D are potentially important targets for selection. Five MTAs associated with physiological traits had pleiotropic effects on grain yield and yield-related traits. Seventy-five MTAs were consistently expressed over several environments indicating stability and more than half of these stable MTAs were found in genes encoding different types of proteins associated with heat stress. CONCLUSIONS We identified 500 significant MTAs in soft winter wheat under HT stress. We found several stable loci across environments and pleiotropic markers controlling physiological and agronomic traits. After further validation, these MTAs can be used in marker-assisted selection and breeding to develop varieties with high stability for grain yield under high temperature.
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Affiliation(s)
- Sumit Pradhan
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Md Ali Babar
- Department of Agronomy, University of Florida, Gainesville, FL, USA.
| | | | - Jahangir Khan
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Dipendra Shahi
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Muhsin Avci
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Jia Guo
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Jordan McBreen
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Senthold Asseng
- Agricultural and Biological Engineering, University of Florida, Gainesville, FL, USA
| | - Salvador Gezan
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, USA
| | | | - Ann Blount
- North Florida Research and Education Cente, Quincy, FL, USA
| | | | - Suraj Sapkota
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Athens, GA, USA
| | | | - Sanju Kunwar
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, USA
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Chen M, Witte CP. A Kinase and a Glycosylase Catabolize Pseudouridine in the Peroxisome to Prevent Toxic Pseudouridine Monophosphate Accumulation. THE PLANT CELL 2020; 32:722-739. [PMID: 31907295 PMCID: PMC7054038 DOI: 10.1105/tpc.19.00639] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/25/2019] [Accepted: 01/06/2020] [Indexed: 05/02/2023]
Abstract
Pseudouridine (Ψ) is a frequent nucleoside modification that occurs in both noncoding RNAs and mRNAs. In pseudouridine, C5 of uracil is attached to the Rib via an unusual C-glycosidic bond. This RNA modification is introduced on the RNA by site-specific transglycosylation of uridine (U), a process mediated by pseudouridine synthases. RNA is subject to constant turnover, releasing free pseudouridine, but the metabolic fate of pseudouridine in eukaryotes is unclear. Here, we show that in Arabidopsis (Arabidopsis thaliana), pseudouridine is catabolized in the peroxisome by (1) a pseudouridine kinase (PUKI) from the PfkB family that generates 5'-pseudouridine monophosphate (5'-ΨMP) and (2) a ΨMP glycosylase (PUMY) that hydrolyzes ΨMP to uracil and ribose-5-phosphate. Compromising pseudouridine catabolism leads to strong pseudouridine accumulation and increased ΨMP content. ΨMP is toxic, causing delayed germination and growth inhibition, but compromising pseudouridine catabolism does not affect the Ψ/U ratios in RNA. The bipartite peroxisomal PUKI and PUMY are conserved in plants and algae, whereas some fungi and most animals (except mammals) possess a PUMY-PUKI fusion protein, likely in mitochondria. We propose that vacuolar turnover of ribosomal RNA produces most of the pseudouridine pool via 3'-ΨMP, which is imported through the cytosol into the peroxisomes for degradation by PUKI and PUMY, a process involving a toxic 5'-ΨMP intermediate.
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Affiliation(s)
- Mingjia Chen
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, Hannover 30419, Germany
| | - Claus-Peter Witte
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, Hannover 30419, Germany
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Hošek P, Hoyerová K, Kiran NS, Dobrev PI, Zahajská L, Filepová R, Motyka V, Müller K, Kamínek M. Distinct metabolism of N-glucosides of isopentenyladenine and trans-zeatin determines cytokinin metabolic spectrum in Arabidopsis. THE NEW PHYTOLOGIST 2020; 225:2423-2438. [PMID: 31682013 DOI: 10.1111/nph.16310] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 10/26/2019] [Indexed: 05/10/2023]
Abstract
The diversity of cytokinin (CK) metabolites suggests their interconversions are the predominant regulatory mechanism of CK action. Nevertheless, little is known about their directionality and kinetics in planta. CK metabolite levels were measured in 2-wk-old Arabidopsis thaliana plants at several time points up to 100 min following exogenous application of selected CKs. The data were then evaluated qualitatively and by mathematical modeling. Apart from elevated levels of trans-zeatin (tZ) metabolites upon application of N6 -(Δ2 -isopentenyl)adenine (iP), we observed no conversions between the individual CK-types - iP, tZ, dihydrozeatin (DHZ) and cis-zeatin (cZ). In particular, there was no sign of isomerization between tZ and cZ families. Also, no increase of DHZ-type CKs was observed after application of tZ, suggesting low baseline activity of zeatin reductase. Among N-glucosides, those of iP were not converted back to iP while tZ N-glucosides were cleaved to tZ bases, thus affecting the whole metabolic spectrum. We present the first large-scale study of short-term CK metabolism kinetics and show that tZ N7- and N9-glucosides are metabolized in vivo. We thus refute the generally accepted hypothesis that N-glucosylation irreversibly inactivates CKs. The subsequently constructed mathematical model provides estimates of the metabolic conversion rates.
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Affiliation(s)
- Petr Hošek
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Klára Hoyerová
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Nagavalli S Kiran
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Petre I Dobrev
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Lenka Zahajská
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Roberta Filepová
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Václav Motyka
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Karel Müller
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Miroslav Kamínek
- The Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 02, Praha 6, Czech Republic
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Hoyerová K, Hošek P. New Insights Into the Metabolism and Role of Cytokinin N-Glucosides in Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:741. [PMID: 32582261 PMCID: PMC7292203 DOI: 10.3389/fpls.2020.00741] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/08/2020] [Indexed: 05/18/2023]
Abstract
Cytokinin (CK) N-glucosides are the most abundant group of CK metabolites in many species; however, their physiological role in planta was for a long time perceived as irreversible storage CK forms only. Recently, a comprehensive screen showed that only vascular plants form CK N-glucosides in contrast to mosses, algae, and fungi. The formation of CK N-glucosides as biologically inactive CK conjugates thus represents an evolutionarily young mechanism for deactivation of CK bases. Even though CK N-glucosides are not biologically active themselves due to their inability to activate the CK perception system, new data on CK N-glucoside metabolism show that trans-zeatin (tZ) N7- and N9-glucosides are metabolized in vivo, efficiently releasing free CK bases that are most probably responsible for the biological activities observed in a number of bioassays. Moreover, CK N-glucosides' subcellular localization as well as their abundance in xylem both point to their possible plasma membrane transport and indicate a role also as CK transport forms. Identification of the enzyme(s) responsible for the hydrolysis of tZ N7- and N9-glucosides, as well as the discovery of putative CK N-glucoside plasma membrane transporter, would unveil important parts of the overall picture of CK metabolic interconversions and their physiological importance.
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11
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Boison D, Yegutkin GG. Adenosine Metabolism: Emerging Concepts for Cancer Therapy. Cancer Cell 2019; 36:582-596. [PMID: 31821783 PMCID: PMC7224341 DOI: 10.1016/j.ccell.2019.10.007] [Citation(s) in RCA: 170] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/23/2019] [Accepted: 10/18/2019] [Indexed: 12/20/2022]
Abstract
Adenosine is a key metabolic and immune-checkpoint regulator implicated in the tumor escape from the host immune system. Major gaps in knowledge that impede the development of effective adenosine-based therapeutics include: (1) lack of consideration of redundant pathways controlling ATP and adenosine levels; (2) lack of distinction between receptor-dependent and -independent effects of adenosine, and (3) focus on extracellular adenosine without consideration of intracellular metabolism and compartmentalization. In light of current clinical trials, we provide an overview of adenosine metabolism and point out the need for a more careful evaluation of the entire purinome in emerging cancer therapies.
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Affiliation(s)
- Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson & New Jersey Medical Schools, Rutgers University, Piscataway, NJ 08854, USA; Rutgers Brain Health Institute, Piscataway, NJ 08854, USA.
| | - Gennady G Yegutkin
- MediCity Research Laboratory, University of Turku, Tykistökatu 6A, Turku, 20520, Finland.
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12
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Chen MS, Zhao ML, Wang GJ, He HY, Bai X, Pan BZ, Fu QT, Tao YB, Tang MY, Martínez-Herrera J, Xu ZF. Transcriptome analysis of two inflorescence branching mutants reveals cytokinin is an important regulator in controlling inflorescence architecture in the woody plant Jatropha curcas. BMC PLANT BIOLOGY 2019; 19:468. [PMID: 31684864 PMCID: PMC6830001 DOI: 10.1186/s12870-019-2069-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 10/09/2019] [Indexed: 06/08/2023]
Abstract
BACKGROUND In higher plants, inflorescence architecture is an important agronomic trait directly determining seed yield. However, little information is available on the regulatory mechanism of inflorescence development in perennial woody plants. Based on two inflorescence branching mutants, we investigated the transcriptome differences in inflorescence buds between two mutants and wild-type (WT) plants by RNA-Seq to identify the genes and regulatory networks controlling inflorescence architecture in Jatropha curcas L., a perennial woody plant belonging to Euphorbiaceae. RESULTS Two inflorescence branching mutants were identified in germplasm collection of Jatropha. The duo xiao hua (dxh) mutant has a seven-order branch inflorescence, and the gynoecy (g) mutant has a three-order branch inflorescence, while WT Jatropha has predominantly four-order branch inflorescence, occasionally the three- or five-order branch inflorescences in fields. Using weighted gene correlation network analysis (WGCNA), we identified several hub genes involved in the cytokinin metabolic pathway from modules highly associated with inflorescence phenotypes. Among them, Jatropha ADENOSINE KINASE 2 (JcADK2), ADENINE PHOSPHORIBOSYL TRANSFERASE 1 (JcAPT1), CYTOKININ OXIDASE 3 (JcCKX3), ISOPENTENYLTRANSFERASE 5 (JcIPT5), LONELY GUY 3 (JcLOG3) and JcLOG5 may participate in cytokinin metabolic pathway in Jatropha. Consistently, exogenous application of cytokinin (6-benzyladenine, 6-BA) on inflorescence buds induced high-branch inflorescence phenotype in both low-branch inflorescence mutant (g) and WT plants. These results suggested that cytokinin is an important regulator in controlling inflorescence branching in Jatropha. In addition, comparative transcriptome analysis showed that Arabidopsis homologous genes Jatropha AGAMOUS-LIKE 6 (JcAGL6), JcAGL24, FRUITFUL (JcFUL), LEAFY (JcLFY), SEPALLATAs (JcSEPs), TERMINAL FLOWER 1 (JcTFL1), and WUSCHEL-RELATED HOMEOBOX 3 (JcWOX3), were differentially expressed in inflorescence buds between dxh and g mutants and WT plants, indicating that they may participate in inflorescence development in Jatropha. The expression of JcTFL1 was downregulated, while the expression of JcLFY and JcAP1 were upregulated in inflorescences in low-branch g mutant. CONCLUSIONS Cytokinin is an important regulator in controlling inflorescence branching in Jatropha. The regulation of inflorescence architecture by the genes involved in floral development, including TFL1, LFY and AP1, may be conservative in Jatropha and Arabidopsis. Our results provide helpful information for elucidating the regulatory mechanism of inflorescence architecture in Jatropha.
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Affiliation(s)
- Mao-Sheng Chen
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
| | - Mei-Li Zhao
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Gui-Juan Wang
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
| | - Hui-Ying He
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
| | - Xue Bai
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Bang-Zhen Pan
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
| | - Qian-Tang Fu
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
| | - Yan-Bin Tao
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
| | - Ming-Yong Tang
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
| | - Jorge Martínez-Herrera
- Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Campo Experimental Huimanguillo, Huimanguillo, Tabasco Mexico
| | - Zeng-Fu Xu
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303 Yunnan China
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Ohler L, Niopek-Witz S, Mainguet SE, Möhlmann T. Pyrimidine Salvage: Physiological Functions and Interaction with Chloroplast Biogenesis. PLANT PHYSIOLOGY 2019; 180:1816-1828. [PMID: 31101721 PMCID: PMC6670073 DOI: 10.1104/pp.19.00329] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/01/2019] [Indexed: 05/07/2023]
Abstract
The synthesis of pyrimidine nucleotides, an essential process in every organism, is accomplished by de novo synthesis or by salvaging pyrimdines from e.g. nucleic acid turnover. Here, we identify two Arabidopsis (Arabidopsis thaliana) uridine/cytidine kinases, UCK1 and UCK2, which are located in the cytosol and are responsible for the majority of pyrimidine salvage activity in vivo. In addition, the chloroplast has an active uracil salvage pathway. Uracil phosphoribosyltransferase (UPP) catalyzes the initial step in this pathway and is required for the establishment of photosynthesis, as revealed by analysis of upp mutants. The upp knockout mutants are unable to grow photoautotrophically, and knockdown mutants exhibit a variegated phenotype, with leaves that have chlorotic pale areas. Moreover, the upp mutants did not show altered expression of chloroplast-encoded genes, but transcript accumulation of the LIGHT HARVESTING COMPLEX B nuclear genes LHCB1.2 and LHCB2.3 was markedly reduced. An active UPP homolog from Escherichia coli failed to complement the upp mutant phenotype when targeted to the chloroplast, suggesting that the catalytic function of UPP is not the important factor for the chloroplast phenotype. Indeed, the expression of catalytically inactive Arabidopsis UPP, generated by introduction of point mutations, did complement the upp chloroplast phenotype. These results suggest that UPP has a vital function in chloroplast biogenesis unrelated to its catalytic activity and driven by a moonlighting function.
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Affiliation(s)
- Lisa Ohler
- Pflanzenphysiologie, Fachbereich Biologie, Universität Kaiserslautern, Erwin-Schrödinger-Strasse, D-67663 Kaiserslautern, Germany
| | - Sandra Niopek-Witz
- Pflanzenphysiologie, Fachbereich Biologie, Universität Kaiserslautern, Erwin-Schrödinger-Strasse, D-67663 Kaiserslautern, Germany
| | - Samuel E Mainguet
- INRA-URGV, 91057 Evry, France - Université Paris-Sud 11, ED145 Sciences du Végétal, 91405 Orsay, France
| | - Torsten Möhlmann
- Pflanzenphysiologie, Fachbereich Biologie, Universität Kaiserslautern, Erwin-Schrödinger-Strasse, D-67663 Kaiserslautern, Germany
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Dissecting Heterosis During the Ear Inflorescence Development Stage in Maize via a Metabolomics-based Analysis. Sci Rep 2019; 9:212. [PMID: 30659214 PMCID: PMC6338801 DOI: 10.1038/s41598-018-36446-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/13/2018] [Indexed: 11/08/2022] Open
Abstract
Heterosis can increase the yield of many crops and has been extensively applied in agriculture. In maize, female inflorescence architecture directly determines grain yield. Thus, exploring the relationship between early maize ear inflorescence development and heterosis regarding yield-related traits may be helpful for characterizing the molecular mechanisms underlying heterotic performance. In this study, we fine mapped the overdominant heterotic locus (hlEW2b), associated with ear width, in an approximately 1.98-Mb region based on analyses of chromosome segment substitution lines and the corresponding testcross population. Maize ear inflorescences at the floral meristem stage were collected from two inbred lines, one chromosome segment substitution line that carried hlEW2b (sub-CSSL16), the receptor parent lx9801, and the Zheng58 × sub-CSSL16 and Zheng58 × lx9801 hybrid lines. A total of 256 metabolites were identified, including 31 and 24 metabolites that were differentially accumulated between the two hybrid lines and between the two inbred lines, respectively. Most of these metabolites are involved in complex regulatory mechanisms important for maize ear development. For example, nucleotides are basic metabolites affecting cell composition and carbohydrate synthesis. Additionally, nicotinate and nicotinamide metabolism is important for photosynthesis, plant stress responses, and cell expansion. Moreover, flavonoid and phenolic metabolites regulate auxin transport and cell apoptosis. Meanwhile, phytohormone biosynthesis and distribution influence the cell cycle and cell proliferation. Our results revealed that changes in metabolite contents may affect the heterotic performance related to ear width and yield in maize hybrid lines. This study provides new clues in heterosis at the metabolomics level and implies that differentially accumulated metabolites made distinct contributions to the heterosis at an early stage of ear inflorescences development.
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15
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Melino VJ, Casartelli A, George J, Rupasinghe T, Roessner U, Okamoto M, Heuer S. RNA Catabolites Contribute to the Nitrogen Pool and Support Growth Recovery of Wheat. FRONTIERS IN PLANT SCIENCE 2018; 9:1539. [PMID: 30455708 PMCID: PMC6230992 DOI: 10.3389/fpls.2018.01539] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/01/2018] [Indexed: 05/23/2023]
Abstract
Turn-over of RNA and catabolism of nucleotides releases one to four ammonia molecules; the released nutrients being reassimilated into primary metabolism. Preliminary evidence indicates that monocots store high levels of free nucleotides and nucleosides but their potential as a source of internal organic nitrogen for use and remobilization is uncharted. Early tillering wheat plants were therefore starved of N over a 5-day time-course with examination of nucleic acid yields in whole shoots, young and old leaves and roots. Nucleic acids constituted ∼4% of the total N pool of N starved wheat plants, which was comparable with the N available from nitrate (NO3 -) and greater than that available from the sum of 20 proteinogenic amino acids. Methods were optimized to detect nucleotide (purine and pyrimidine) metabolites, and wheat orthologs of RNA degradation (TaRNS), nucleoside transport (TaENT1, TaENT3) and salvage (TaADK) were identified. It was found that N starved wheat roots actively catabolised RNA and specific purines but accumulated pyrimidines. Reduced levels of RNA corresponded with induction of TaRNS2, TaENT1, TaENT3, and TaADK in the roots. Reduced levels of GMP, guanine, xanthine, allantoin, allantoate and glyoxylate in N starved roots correlated with accumulation of allantoate and glyoxylate in the oldest leaf, suggesting translocation of allantoin. Furthermore, N starved wheat plants exogenously supplied with N in the form of purine catabolites grew and photosynthesized as well as those plants re-supplied with NO3 -. These results support the hypothesis that the nitrogen and carbon recovered from purine metabolism can support wheat growth.
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Affiliation(s)
- Vanessa Jane Melino
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
- School of Agriculture and Food, University of Melbourne, Parkville, VIC, Australia
| | - Alberto Casartelli
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
| | - Jessey George
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Ute Roessner
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Mamoru Okamoto
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
| | - Sigrid Heuer
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, United Kingdom
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16
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Ashihara H, Stasolla C, Fujimura T, Crozier A. Purine salvage in plants. PHYTOCHEMISTRY 2018; 147:89-124. [PMID: 29306799 DOI: 10.1016/j.phytochem.2017.12.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/10/2017] [Accepted: 12/14/2017] [Indexed: 05/04/2023]
Abstract
Purine bases and nucleosides are produced by turnover of nucleotides and nucleic acids as well as from some cellular metabolic pathways. Adenosine released from the S-adenosyl-L-methionine cycle is linked to many methyltransferase reactions, such as the biosynthesis of caffeine and glycine betaine. Adenine is produced by the methionine cycles, which is related to other biosynthesis pathways, such those for the production of ethylene, nicotianamine and polyamines. These purine compounds are recycled for nucleotide biosynthesis by so-called "salvage pathways". However, the salvage pathways are not merely supplementary routes for nucleotide biosynthesis, but have essential functions in many plant processes. In plants, the major salvage enzymes are adenine phosphoribosyltransferase (EC 2.4.2.7) and adenosine kinase (EC 2.7.1.20). AMP produced by these enzymes is converted to ATP and utilised as an energy source as well as for nucleic acid synthesis. Hypoxanthine, guanine, inosine and guanosine are salvaged to IMP and GMP by hypoxanthine/guanine phosphoribosyltransferase (EC 2.4.2.8) and inosine/guanosine kinase (EC 2.7.1.73). In contrast to de novo purine nucleotide biosynthesis, synthesis by the salvage pathways is extremely favourable, energetically, for cells. In addition, operation of the salvage pathway reduces the intracellular levels of purine bases and nucleosides which inhibit other metabolic reactions. The purine salvage enzymes also catalyse the respective formation of cytokinin ribotides, from cytokinin bases, and cytokinin ribosides. Since cytokinin bases are the active form of cytokinin hormones, these enzymes act to maintain homeostasis of cellular cytokinin bioactivity. This article summarises current knowledge of purine salvage pathways and their possible function in plants and purine salvage activities associated with various physiological phenomena are reviewed.
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Affiliation(s)
- Hiroshi Ashihara
- Department of Biology, Ochanomizu University, Bunkyo-ku, Tokyo, 112-8610, Japan.
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, R3T 2N2, Canada
| | - Tatsuhito Fujimura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-8572, Japan
| | - Alan Crozier
- Department of Nutrition, University of California, Davis, CA, 95616-5270, USA
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17
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Schroeder RY, Zhu A, Eubel H, Dahncke K, Witte CP. The ribokinases of Arabidopsis thaliana and Saccharomyces cerevisiae are required for ribose recycling from nucleotide catabolism, which in plants is not essential to survive prolonged dark stress. THE NEW PHYTOLOGIST 2018; 217:233-244. [PMID: 28921561 DOI: 10.1111/nph.14782] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/05/2017] [Indexed: 06/07/2023]
Abstract
Nucleotide catabolism in Arabidopsis thaliana and Saccharomyces cerevisiae leads to the release of ribose, which requires phosphorylation to ribose-5-phosphate mediated by ribokinase (RBSK). We aimed to characterize RBSK in plants and yeast, to quantify the contribution of plant nucleotide catabolism to the ribose pool, and to investigate whether ribose carbon contributes to dark stress survival of plants. We performed a phylogenetic analysis and determined the kinetic constants of plant-expressed Arabidopsis and yeast RBSKs. Using mass spectrometry, several metabolites were quantified in AtRBSK mutants and double mutants with genes of nucleoside catabolism. Additionally, the dark stress performance of several nucleotide metabolism mutants and rbsk was compared. The plant PfkB family of sugar kinases forms nine major clades likely representing distinct biochemical functions, one of them RBSK. Nucleotide catabolism is the dominant ribose source in plant metabolism and is highly induced by dark stress. However, rbsk cannot be discerned from the wild type in dark stress. Interestingly, the accumulation of guanosine in a guanosine deaminase mutant strongly enhances dark stress symptoms. Although nucleotide catabolism contributes to carbon mobilization upon darkness and is the dominant source of ribose, the contribution appears to be of minor importance for dark stress survival.
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Affiliation(s)
- Rebekka Y Schroeder
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany
| | - Anting Zhu
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany
| | - Holger Eubel
- Department of Plant Proteomics, Institute of Plant Genetics, Leibniz University Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany
| | - Kathleen Dahncke
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, Albrecht-Thaer-Weg 6, Berlin, 14195, Germany
| | - Claus-Peter Witte
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany
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18
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Czarnocka W, Van Der Kelen K, Willems P, Szechyńska-Hebda M, Shahnejat-Bushehri S, Balazadeh S, Rusaczonek A, Mueller-Roeber B, Van Breusegem F, Karpiński S. The dual role of LESION SIMULATING DISEASE 1 as a condition-dependent scaffold protein and transcription regulator. PLANT, CELL & ENVIRONMENT 2017; 40:2644-2662. [PMID: 28555890 DOI: 10.1111/pce.12994] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/14/2017] [Accepted: 05/15/2017] [Indexed: 06/07/2023]
Abstract
Since its discovery over two decades ago as an important cell death regulator in Arabidopsis thaliana, the role of LESION SIMULATING DISEASE 1 (LSD1) has been studied intensively within both biotic and abiotic stress responses as well as with respect to plant fitness regulation. However, its molecular mode of action remains enigmatic. Here, we demonstrate that nucleo-cytoplasmic LSD1 interacts with a broad range of other proteins that are engaged in various molecular pathways such as ubiquitination, methylation, cell cycle control, gametogenesis, embryo development and cell wall formation. The interaction of LSD1 with these partners is dependent on redox status, as oxidative stress significantly changes the quantity and types of LSD1-formed complexes. Furthermore, we show that LSD1 regulates the number and size of leaf mesophyll cells and affects plant vegetative growth. Importantly, we also reveal that in addition to its function as a scaffold protein, LSD1 acts as a transcriptional regulator. Taken together, our results demonstrate that LSD1 plays a dual role within the cell by acting as a condition-dependent scaffold protein and as a transcription regulator.
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Affiliation(s)
- Weronika Czarnocka
- Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776, Warsaw, Poland
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776, Warsaw, Poland
| | - Katrien Van Der Kelen
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 927, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 927, 9052, Ghent, Belgium
| | - Patrick Willems
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 927, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 927, 9052, Ghent, Belgium
| | - Magdalena Szechyńska-Hebda
- Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776, Warsaw, Poland
- Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek Street 21, 30-239, Cracow, Poland
| | - Sara Shahnejat-Bushehri
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht Street 24-25, 14476, Potsdam, Germany
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Salma Balazadeh
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht Street 24-25, 14476, Potsdam, Germany
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Anna Rusaczonek
- Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776, Warsaw, Poland
| | - Bernd Mueller-Roeber
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht Street 24-25, 14476, Potsdam, Germany
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Frank Van Breusegem
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 927, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 927, 9052, Ghent, Belgium
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776, Warsaw, Poland
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19
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Trdá L, Barešová M, Šašek V, Nováková M, Zahajská L, Dobrev PI, Motyka V, Burketová L. Cytokinin Metabolism of Pathogenic Fungus Leptosphaeria maculans Involves Isopentenyltransferase, Adenosine Kinase and Cytokinin Oxidase/Dehydrogenase. Front Microbiol 2017; 8:1374. [PMID: 28785249 PMCID: PMC5521058 DOI: 10.3389/fmicb.2017.01374] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/06/2017] [Indexed: 12/23/2022] Open
Abstract
Among phytohormones, cytokinins (CKs) play an important role in controlling crucial aspects of plant development. Not only plants but also diverse microorganisms are able to produce phytohormones, including CKs, though knowledge concerning their biosynthesis and metabolism is still limited. In this work we demonstrate that the fungus Leptosphaeria maculans, a hemi-biotrophic pathogen of oilseed rape (Brassica napus), causing one of the most damaging diseases of this crop, is able to modify the CK profile in infected B. napus tissues, as well as produce a wide range of CKs in vitro, with the cis-zeatin derivatives predominating. The endogenous CK spectrum of L. maculans in vitro consists mainly of free CK bases, as opposed to plants, where other CK forms are mostly more abundant. Using functional genomics, enzymatic and feeding assays with CK bases supplied to culture media, we show that L. maculans contains a functional: (i) isopentenyltransferase (IPT) involved in cZ production; (ii) adenosine kinase (AK) involved in phosphorylation of CK ribosides to nucleotides; and (iii) CK-degradation enzyme cytokinin oxidase/dehydrogenase (CKX). Our data further indicate the presence of cis-trans isomerase, zeatin O-glucosyltransferase(s) and N6-(Δ2-isopentenyl)adenine hydroxylating enzyme. Besides, we report on a crucial role of LmAK for L. maculans fitness and virulence. Altogether, in this study we characterize in detail the CK metabolism of the filamentous fungi L. maculans and report its two novel components, the CKX and CK-related AK activities, according to our knowledge for the first time in the fungal kingdom. Based on these findings, we propose a model illustrating CK metabolism pathways in L. maculans.
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Affiliation(s)
- Lucie Trdá
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
| | - Monika Barešová
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
- Department of Biochemistry and Microbiology, Institute of Chemical TechnologyPrague, Czechia
| | - Vladimír Šašek
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
| | - Miroslava Nováková
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
| | - Lenka Zahajská
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
| | - Petre I. Dobrev
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
| | - Václav Motyka
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
| | - Lenka Burketová
- Institute of Experimental Botany, The Czech Academy of SciencesPrague, Czechia
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Luzarowski M, Kosmacz M, Sokolowska E, Jasińska W, Willmitzer L, Veyel D, Skirycz A. Affinity purification with metabolomic and proteomic analysis unravels diverse roles of nucleoside diphosphate kinases. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3487-3499. [PMID: 28586477 PMCID: PMC5853561 DOI: 10.1093/jxb/erx183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/04/2017] [Indexed: 05/22/2023]
Abstract
Interactions between metabolites and proteins play an integral role in all cellular functions. Here we describe an affinity purification (AP) approach in combination with LC/MS-based metabolomics and proteomics that allows, to our knowledge for the first time, analysis of protein-metabolite and protein-protein interactions simultaneously in plant systems. More specifically, we examined protein and small-molecule partners of the three (of five) nucleoside diphosphate kinases present in the Arabidopsis genome (NDPK1-NDPK3). The bona fide role of NDPKs is the exchange of terminal phosphate groups between nucleoside diphosphates (NDPs) and triphosphates (NTPs). However, other functions have been reported, which probably depend on both the proteins and small molecules specifically interacting with the NDPK. Using our approach we identified 23, 17, and 8 novel protein partners of NDPK1, NDPK2, and NDPK3, respectively, with nucleotide-dependent proteins such as actin and adenosine kinase 2 being enriched. Particularly interesting, however, was the co-elution of glutathione S-transferases (GSTs) and reduced glutathione (GSH) with the affinity-purified NDPK1 complexes. Following up on this finding, we could demonstrate that NDPK1 undergoes glutathionylation, opening a new paradigm of NDPK regulation in plants. The described results extend our knowledge of NDPKs, the key enzymes regulating NDP/NTP homeostasis.
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Affiliation(s)
- Marcin Luzarowski
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | - Monika Kosmacz
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | - Ewelina Sokolowska
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | - Weronika Jasińska
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | - Lothar Willmitzer
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | - Daniel Veyel
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | - Aleksandra Skirycz
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
- Correspondence:
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Luzarowski M, Kosmacz M, Sokolowska E, Jasinska W, Willmitzer L, Veyel D, Skirycz A. Affinity purification with metabolomic and proteomic analysis unravels diverse roles of nucleoside diphosphate kinases. JOURNAL OF EXPERIMENTAL BOTANY 2017. [PMID: 28586477 DOI: 10.93/jxb/erx183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Interactions between metabolites and proteins play an integral role in all cellular functions. Here we describe an affinity purification (AP) approach in combination with LC/MS-based metabolomics and proteomics that allows, to our knowledge for the first time, analysis of protein-metabolite and protein-protein interactions simultaneously in plant systems. More specifically, we examined protein and small-molecule partners of the three (of five) nucleoside diphosphate kinases present in the Arabidopsis genome (NDPK1-NDPK3). The bona fide role of NDPKs is the exchange of terminal phosphate groups between nucleoside diphosphates (NDPs) and triphosphates (NTPs). However, other functions have been reported, which probably depend on both the proteins and small molecules specifically interacting with the NDPK. Using our approach we identified 23, 17, and 8 novel protein partners of NDPK1, NDPK2, and NDPK3, respectively, with nucleotide-dependent proteins such as actin and adenosine kinase 2 being enriched. Particularly interesting, however, was the co-elution of glutathione S-transferases (GSTs) and reduced glutathione (GSH) with the affinity-purified NDPK1 complexes. Following up on this finding, we could demonstrate that NDPK1 undergoes glutathionylation, opening a new paradigm of NDPK regulation in plants. The described results extend our knowledge of NDPKs, the key enzymes regulating NDP/NTP homeostasis.
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Affiliation(s)
- Marcin Luzarowski
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Monika Kosmacz
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ewelina Sokolowska
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Weronika Jasinska
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Lothar Willmitzer
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Daniel Veyel
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Aleksandra Skirycz
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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Riggs JW, Cavales PC, Chapiro SM, Callis J. Identification and biochemical characterization of the fructokinase gene family in Arabidopsis thaliana. BMC PLANT BIOLOGY 2017; 17:83. [PMID: 28441933 PMCID: PMC5405513 DOI: 10.1186/s12870-017-1031-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 04/12/2017] [Indexed: 05/09/2023]
Abstract
BACKGROUND Fructose is an abundant sugar in plants as it is a breakdown product of both major sucrose-cleaving enzymes. To enter metabolism, fructose is phosphorylated by a fructokinase (FRK). Known FRKs are members of a diverse family of carbohydrate/purine kinases known as the phosphofructokinase B (pfkB) family. The complete complement of active fructokinases has not been reported for any plant species. RESULTS Protein sequence analysis of the 22 Arabidopsis thaliana pfkB members identified eight highly related predicted proteins, including one with previously demonstrated FRK activity. For one, At1g50390, the predicted open reading frame is half the size of active FRKs, and only incompletely spliced RNAs were identified, which led to a premature stop codon, both indicating that this gene does not produce active FRK. The remaining seven proteins were expressed in E. coli and phosphorylated fructose specifically in vitro leading us to propose a unifying nomenclature (FRK1-7). Substrate inhibition was observed for fructose in all FRKs except FRK1. Fructose binding was on the same order of magnitude for FRK1-6, between 260 and 480 μM. FRK7 was an outlier with a fructose Km of 12 μM. ATP binding was similar for all FRKs and ranged between 52 and 280 μM. YFP-tagged AtFRKs were cytosolic, except plastidic FRK3. T-DNA alleles with non-detectable wild-type RNAs in five of the seven active FRK genes produced no overt phenotype. We extended our sequence comparisons to include putative FRKs encoded in other plant sequenced genomes. We observed that different subgroups expanded subsequent to speciation. CONCLUSIONS Arabidopsis thaliana as well as all other plant species analyzed contain multiple copies of genes encoding FRK activity. Sequence comparisons among multiple species identified a minimal set of three distinct FRKs present on all species investigated including a plastid-localized form. The selective expansion of specific isozymes results in differences in FRK gene number among species. AtFRKs exhibit substrate inhibition, typical of their mammalian counterparts with the single AtFRK1 lacking this property, suggesting it may have a distinct in vivo role. Results presented here provide a starting point for the engineering of specific FRKs to affect biomass production.
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Affiliation(s)
- John W. Riggs
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, 1 Shields Ave, Davis, CA 95616 USA
| | - Philip C. Cavales
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, 1 Shields Ave, Davis, CA 95616 USA
| | - Sonia M. Chapiro
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, 1 Shields Ave, Davis, CA 95616 USA
- Present Address: Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
- Present Address: Joint Bioenergy Institute, Emeryville, CA 94608 USA
| | - Judy Callis
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, 1 Shields Ave, Davis, CA 95616 USA
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Liu C, Pedersen C, Schultz-Larsen T, Aguilar GB, Madriz-Ordeñana K, Hovmøller MS, Thordal-Christensen H. The stripe rust fungal effector PEC6 suppresses pattern-triggered immunity in a host species-independent manner and interacts with adenosine kinases. THE NEW PHYTOLOGIST 2016. [PMID: 27252028 DOI: 10.1111/nph.14034] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/25/2016] [Indexed: 05/20/2023]
Abstract
We identified a wheat stripe rust (Puccinia striiformis) effector candidate (PEC6) with pattern-triggered immunity (PTI) suppression function and its corresponding host target. PEC6 compromised PTI host species-independently. In Nicotiana benthamiana, it hampers reactive oxygen species (ROS) accumulation and callose deposition induced by Pseudomonas fluorescens. In Arabidopsis, plants expressing PEC6 were more susceptible to Pseudomonas syringae pv. tomato (Pto) DC3000 ΔAvrPto/ΔAvrPtoB. In wheat, PEC6-suppression of P. fluorescens-elicited PTI was revealed by the fact that it allowed activation of effector-triggered immunity by Pto DC3000. Knocking down of PEC6 expression by virus-mediated host-induced gene silencing decreased the number of rust pustules, uncovering PEC6 as an important pathogenicity factor. PEC6, overexpressed in plant cells without its signal peptide, was localized to the nucleus and cytoplasm. A yeast two-hybrid assay showed that PEC6 interacts with both wheat and Arabidopsis adenosine kinases (ADKs). Knocking down wheat ADK expression by virus-induced gene silencing reduced leaf growth and enhanced the number of rust pustules, indicating that ADK is important in plant development and defence. ADK plays essential roles in regulating metabolism, cytokinin interconversion and methyl transfer reactions, and our data propose a model where PEC6 may affect one of these processes by targeting ADK to favour fungal growth.
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Affiliation(s)
- Changhai Liu
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Carsten Pedersen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Torsten Schultz-Larsen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Geziel B Aguilar
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Kenneth Madriz-Ordeñana
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
| | - Mogens S Hovmøller
- Department of Agroecology, Aarhus University, Forsøgsvej 1, Slagelse, DK-4200, Denmark
| | - Hans Thordal-Christensen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, DK-1871, Denmark
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24
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Zheng M, Meng Y, Yang C, Zhou Z, Wang Y, Chen B. Protein expression changes during cotton fiber elongation in response to drought stress and recovery. Proteomics 2015; 14:1776-95. [PMID: 24889071 DOI: 10.1002/pmic.201300123] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 04/17/2014] [Accepted: 05/20/2014] [Indexed: 11/06/2022]
Abstract
An investigation to better understand the molecular mechanism of cotton (Gossypium hirsutum L.) fiber elongation in response to drought stress and recovery was conducted using a comparative proteomics analysis. Cotton plants (cv. NuCOTN 33B) were subjected to water deprivation for 10 days followed by a recovery period (with watering) of 5 days. The temporal changes in total proteins in cotton fibers were examined using 2DE. The results revealed that 163 proteins are significantly drought responsive. MS analysis led to the identification of 132 differentially expressed proteins that include some known as well as some novel drought-responsive proteins. These drought responsive fiber proteins in NuCOTN 33B are associated with a variety of cellular functions, i.e. signal transduction, protein processing, redox homeostasis, cell wall modification, metabolisms of carbon, energy, lipid, lignin, and flavonoid. The results suggest that the enhancement of the perception of drought stress, a new balance of the metabolism of the biosynthesis of cell wall components and cytoskeleton homeostasis plays an important role in the response of cotton fibers to drought stress. Overall, the current study provides an overview of the molecular mechanism of drought response in cotton fiber cells.
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Affiliation(s)
- Mi Zheng
- College of Agriculture, Nanjing Agricultural University, Nanjing, P. R. China; State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, P. R. China
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25
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Perotti VE, Moreno AS, Trípodi KEJ, Meier G, Bello F, Cocco M, Vázquez D, Anderson C, Podestá FE. Proteomic and metabolomic profiling of Valencia orange fruit after natural frost exposure. PHYSIOLOGIA PLANTARUM 2015; 153:337-54. [PMID: 25132553 DOI: 10.1111/ppl.12259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 03/14/2014] [Accepted: 06/25/2014] [Indexed: 05/04/2023]
Abstract
The aim of this study was to evaluate the response of orange fruit (Citrus sinensis var. Valencia Late) to freezing stress in planta, both immediately after the natural event and after a week, in order to understand the biochemical and molecular basis of the changes that later derive in internal and external damage symptoms. Using two-dimensional differential gel electrophoresis to analyze exposed and non-exposed fruit, 27 differential protein spots were detected in juice sacs and flavedo, among all comparisons made. Also, primary and secondary metabolites relative contents were analyzed in both tissues by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry, respectively. Proteins and compounds involved in regulatory functions, iron metabolism, oxidative damage and carbohydrate metabolism were the most affected. Interestingly, three glycolytic enzymes were induced by cold, and there was an increase in fermentation products (volatiles); all of that suggests that more energy generation might be required from glycolysis to counter the cold stress. Moreover, a notable increase in sugar levels was observed after frost, but it was not at the expense of organic acids utilization. Consequently, these results suggest a probable redistribution of photoassimilates in the frost-exposed plants, tending to restore the homeostasis altered by that severe type of stress. Isosinensetin was the most cold-sensitive secondary metabolite because it could not be detected at all after the frost, constituting a possible tool to early diagnose freezing damage.
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Affiliation(s)
- Valeria E Perotti
- Centro de Estudios Fotosintéticos y Bioquímicos, CONICET, and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, 2000, Argentina
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26
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Jackel JN, Buchmann RC, Singhal U, Bisaro DM. Analysis of geminivirus AL2 and L2 proteins reveals a novel AL2 silencing suppressor activity. J Virol 2015. [PMID: 25552721 DOI: 10.1128/jvi.02625-2614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
UNLABELLED Both posttranscriptional and transcriptional gene silencing (PTGS and TGS, respectively) participate in defense against the DNA-containing geminiviruses. As a countermeasure, members of the genus Begomovirus (e.g., Cabbage leaf curl virus) encode an AL2 protein that is both a transcriptional activator and a silencing suppressor. The related L2 protein of Beet curly top virus (genus Curtovirus) lacks transcription activation activity. Previous studies showed that both AL2 and L2 suppress silencing by a mechanism that correlates with adenosine kinase (ADK) inhibition, while AL2 in addition activates transcription of cellular genes that negatively regulate silencing pathways. The goal of this study was to clarify the general means by which these viral proteins inhibit various aspects of silencing. We confirmed that AL2 inhibits systemic silencing spread by a mechanism that requires transcription activation activity. Surprisingly, we also found that reversal of PTGS and TGS by ADK inactivation depended on whether experiments were conducted in vegetative or reproductive Nicotiana benthamiana plants (i.e., before or after the vegetative-to-reproductive transition). While AL2 was able to reverse silencing in both vegetative and reproductive plants, L2 and ADK inhibition were effective only in vegetative plants. This suggests that silencing maintenance mechanisms can change during development or in response to stress. Remarkably, we also observed that AL2 lacking its transcription activation domain could reverse TGS in reproductive plants, revealing a third, previously unsuspected AL2 suppression mechanism that depends on neither ADK inactivation nor transcription activation. IMPORTANCE RNA silencing in plants is a multivalent antiviral defense, and viruses respond by elaborating multiple and sometimes multifunctional proteins that inhibit various aspects of silencing. The studies described here add an additional layer of complexity to this interplay. By examining geminivirus AL2 and L2 suppressor activities, we show that L2 is unable to suppress silencing in Nicotiana benthamiana plants that have undergone the vegetative-to-reproductive transition. As L2 was previously shown to be effective in mature Arabidopsis plants, these results illustrate that silencing mechanisms can change during development or in response to stress in ways that may be species specific. The AL2 and L2 proteins are known to share a suppression mechanism that correlates with the ability of both proteins to inhibit ADK, while AL2 in addition can inhibit silencing by transcriptionally activating cellular genes. Here, we also provide evidence for a third AL2 suppression mechanism that depends on neither transcription activation nor ADK inactivation. In addition to revealing the remarkable versatility of AL2, this work highlights the utility of viral suppressors as probes for the analysis of silencing pathways.
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Affiliation(s)
- Jamie N Jackel
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
| | - R Cody Buchmann
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
| | - Udit Singhal
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
| | - David M Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
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27
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Jackel JN, Buchmann RC, Singhal U, Bisaro DM. Analysis of geminivirus AL2 and L2 proteins reveals a novel AL2 silencing suppressor activity. J Virol 2015; 89:3176-87. [PMID: 25552721 PMCID: PMC4337558 DOI: 10.1128/jvi.02625-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/26/2014] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Both posttranscriptional and transcriptional gene silencing (PTGS and TGS, respectively) participate in defense against the DNA-containing geminiviruses. As a countermeasure, members of the genus Begomovirus (e.g., Cabbage leaf curl virus) encode an AL2 protein that is both a transcriptional activator and a silencing suppressor. The related L2 protein of Beet curly top virus (genus Curtovirus) lacks transcription activation activity. Previous studies showed that both AL2 and L2 suppress silencing by a mechanism that correlates with adenosine kinase (ADK) inhibition, while AL2 in addition activates transcription of cellular genes that negatively regulate silencing pathways. The goal of this study was to clarify the general means by which these viral proteins inhibit various aspects of silencing. We confirmed that AL2 inhibits systemic silencing spread by a mechanism that requires transcription activation activity. Surprisingly, we also found that reversal of PTGS and TGS by ADK inactivation depended on whether experiments were conducted in vegetative or reproductive Nicotiana benthamiana plants (i.e., before or after the vegetative-to-reproductive transition). While AL2 was able to reverse silencing in both vegetative and reproductive plants, L2 and ADK inhibition were effective only in vegetative plants. This suggests that silencing maintenance mechanisms can change during development or in response to stress. Remarkably, we also observed that AL2 lacking its transcription activation domain could reverse TGS in reproductive plants, revealing a third, previously unsuspected AL2 suppression mechanism that depends on neither ADK inactivation nor transcription activation. IMPORTANCE RNA silencing in plants is a multivalent antiviral defense, and viruses respond by elaborating multiple and sometimes multifunctional proteins that inhibit various aspects of silencing. The studies described here add an additional layer of complexity to this interplay. By examining geminivirus AL2 and L2 suppressor activities, we show that L2 is unable to suppress silencing in Nicotiana benthamiana plants that have undergone the vegetative-to-reproductive transition. As L2 was previously shown to be effective in mature Arabidopsis plants, these results illustrate that silencing mechanisms can change during development or in response to stress in ways that may be species specific. The AL2 and L2 proteins are known to share a suppression mechanism that correlates with the ability of both proteins to inhibit ADK, while AL2 in addition can inhibit silencing by transcriptionally activating cellular genes. Here, we also provide evidence for a third AL2 suppression mechanism that depends on neither transcription activation nor ADK inactivation. In addition to revealing the remarkable versatility of AL2, this work highlights the utility of viral suppressors as probes for the analysis of silencing pathways.
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Affiliation(s)
- Jamie N Jackel
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
| | - R Cody Buchmann
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
| | - Udit Singhal
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
| | - David M Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Graduate Program in Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, Ohio, USA
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28
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Chatterjee M, Gupta S, Bhar A, Chakraborti D, Basu D, Das S. Analysis of root proteome unravels differential molecular responses during compatible and incompatible interaction between chickpea (Cicer arietinum L.) and Fusarium oxysporum f. sp. ciceri Race1 (Foc1). BMC Genomics 2014; 15:949. [PMID: 25363865 PMCID: PMC4237293 DOI: 10.1186/1471-2164-15-949] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 10/22/2014] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Vascular wilt caused by Fusarium oxysporum f. sp. ciceri Race 1 (Foc1) is a serious disease of chickpea (Cicer arietinum L.) accounting for approximately 10-15% annual crop loss. The fungus invades the plant via roots, colonizes the xylem vessels and prevents the upward translocation of water and nutrients, finally resulting in wilting of the entire plant. Although comparative transcriptomic profiling have highlighted some important signaling molecules, but proteomic studies involving chickpea-Foc1 are limited. The present study focuses on comparative root proteomics of susceptible (JG62) and resistant (WR315) chickpea genotypes infected with Foc1, to understand the mechanistic basis of susceptibility and/or resistance. RESULTS The differential and unique proteins of both genotypes were identified at 48 h, 72 h, and 96 h post Foc1 inoculation. 2D PAGE analyses followed by MALDI-TOF MS and MS/MS identified 100 differentially (>1.5 fold<, p<0.05) or uniquely expressed proteins. These proteins were further categorized into 10 functional classes and grouped into GO (gene ontology) categories. Network analyses of identified proteins revealed intra and inter relationship of these proteins with their neighbors as well as their association with different defense signaling pathways. qRT-PCR analyses were performed to correlate the mRNA and protein levels of some proteins of representative classes. CONCLUSIONS The differential and unique proteins identified indicate their involvement in early defense signaling of the host. Comparative analyses of expression profiles of obtained proteins suggest that albeit some common components participate in early defense signaling in both susceptible and resistant genotypes, but their roles and regulation differ in case of compatible and/or incompatible interactions. Thus, functional characterization of identified PR proteins (PR1, BGL2, TLP), Trypsin protease inhibitor, ABA responsive protein, cysteine protease, protein disulphide isomerase, ripening related protein and albumins are expected to serve as important molecular components for biotechnological application and development of sustainable resistance against Foc1.
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Affiliation(s)
- Moniya Chatterjee
- />Division of Plant Biology, Bose Institute, Centenary Campus, P 1/12, CIT Scheme, VII-M, Kankurgachi, Kolkata, 700054 West Bengal India
| | - Sumanti Gupta
- />Division of Plant Biology, Bose Institute, Centenary Campus, P 1/12, CIT Scheme, VII-M, Kankurgachi, Kolkata, 700054 West Bengal India
| | - Anirban Bhar
- />Division of Plant Biology, Bose Institute, Centenary Campus, P 1/12, CIT Scheme, VII-M, Kankurgachi, Kolkata, 700054 West Bengal India
| | - Dipankar Chakraborti
- />Post Graduate Department of Biotechnology, St. Xavier’s College (Autonomous), 30 Park Street, Kolkata, 700016 India
| | - Debabrata Basu
- />Division of Plant Biology, Bose Institute, Centenary Campus, P 1/12, CIT Scheme, VII-M, Kankurgachi, Kolkata, 700054 West Bengal India
| | - Sampa Das
- />Division of Plant Biology, Bose Institute, Centenary Campus, P 1/12, CIT Scheme, VII-M, Kankurgachi, Kolkata, 700054 West Bengal India
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29
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Proteome alterations of reverse photoperiod-sensitive genic male sterile rice (Oryza sativa L.) at fertility transformation stage. Genes Genomics 2014. [DOI: 10.1007/s13258-014-0205-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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30
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Chen Y, Chen X, Wang H, Bao Y, Zhang W. Examination of the leaf proteome during flooding stress and the induction of programmed cell death in maize. Proteome Sci 2014; 12:33. [PMID: 25028572 PMCID: PMC4099015 DOI: 10.1186/1477-5956-12-33] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/30/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Maize is a major economic crop worldwide, with substantial crop loss attributed to flooding. During a stress response, programmed cell death (PCD) can be an effective way for plants better adapt. To identify flooding stress related PCD proteins in maize leaves, proteomic analysis was performed using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and mass spectrometry. RESULTS Comparative proteomics was combined with physiological and biochemical analysis of maize leaves under flooding stress. Fv/Fm, qP, qN and relative water content (RWC) were found to be altered in response to flooding stress, with an increase in H2O2 content noted in vivo. Furthermore, DNA ladder detection indicated that PCD had occurred under flooding treatment. The maize leaf proteome was analyzed via 2D-DIGE gel, with a total of 32 differentially expressed spots isolated, 31 spots were successfully identified via MALDI-TOF/TOF MS which represent 28 proteins. The identified proteins were related to energy metabolism and photosynthesis, PCD, phytohormones and polyamines. To better characterize the role of translationally controlled tumor protein (TCTP) in PCD during a stress response, mRNA expression was examined in different plants by stress-induced PCD. These included heat stress induced rice protoplasts, Tobacco Mosaic Virus infected tobacco leaves and dark induced rice and Arabidopsis thaliana leaves, all of which showed active PCD, and TCTP expression was increased in different degrees. Moreover, S-adenosylmethionine synthase 2 (SAMS2) and S-adenosylmethionine decarboxylase (SAMDC) mRNA expression were also increased, but ACC synthase (ACS) and ACC oxidase (ACO) mRNA expression were not found in maize leaves following flooding. Lastly, ethylene and polyamine concentrations were increased in response to flooding treatment in maize leaves. CONCLUSIONS Following flooding stress, the photosynthetic systems were damaged, resulting in a disruption in energy metabolism, with the noted photosynthetic decline also possibly attributed to ROS production. The observed PCD could be regulated by TCTP with a possible role for H2O2 in TCTP induction under flooding stress. Additionally, increased SAMS2 expression was closely associated with an increased polyamine synthesis during flooding treatment.
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Affiliation(s)
- Yu Chen
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, PR, China
| | - Xi Chen
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, PR, China
| | - Hongjuan Wang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, PR, China
| | - Yiqun Bao
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, PR, China
| | - Wei Zhang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, PR, China
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31
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Mohannath G, Jackel JN, Lee YH, Buchmann RC, Wang H, Patil V, Adams AK, Bisaro DM. A complex containing SNF1-related kinase (SnRK1) and adenosine kinase in Arabidopsis. PLoS One 2014; 9:e87592. [PMID: 24498147 PMCID: PMC3907550 DOI: 10.1371/journal.pone.0087592] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 12/30/2013] [Indexed: 12/22/2022] Open
Abstract
SNF1-related kinase (SnRK1) in plants belongs to a conserved family that includes sucrose non-fermenting 1 kinase (SNF1) in yeast and AMP-activated protein kinase (AMPK) in animals. These kinases play important roles in the regulation of cellular energy homeostasis and in response to stresses that deplete ATP, they inhibit energy consuming anabolic pathways and promote catabolism. Energy stress is sensed by increased AMP:ATP ratios and in plants, 5′-AMP inhibits inactivation of phosphorylated SnRK1 by phosphatase. In previous studies, we showed that geminivirus pathogenicity proteins interact with both SnRK1 and adenosine kinase (ADK), which phosphorylates adenosine to generate 5′-AMP. This suggested a relationship between SnRK1 and ADK, which we investigate in the studies described here. We demonstrate that SnRK1 and ADK physically associate in the cytoplasm, and that SnRK1 stimulates ADK in vitro by an unknown, non-enzymatic mechanism. Further, altering SnRK1 or ADK activity in transgenic plants altered the activity of the other kinase, providing evidence for in vivo linkage but also revealing that in vivo regulation of these activities is complex. This study establishes the existence of SnRK1-ADK complexes that may play important roles in energy homeostasis and cellular responses to biotic and abiotic stress.
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Affiliation(s)
- Gireesha Mohannath
- Department of Molecular Genetics, Center for Applied Plant Sciences, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Jamie N. Jackel
- Department of Molecular Genetics, Center for Applied Plant Sciences, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Youn Hyung Lee
- Department of Horticultural Biotechnology, Kyung Hee University, Yongin, Korea
| | - R. Cody Buchmann
- Department of Molecular Genetics, Center for Applied Plant Sciences, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Hui Wang
- Department of Molecular Genetics, Center for Applied Plant Sciences, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Veena Patil
- Department of Molecular Genetics, Center for Applied Plant Sciences, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Allie K. Adams
- Department of Molecular Genetics, Center for Applied Plant Sciences, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - David M. Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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Kopečná M, Blaschke H, Kopečný D, Vigouroux A, Končitíková R, Novák O, Kotland O, Strnad M, Moréra S, von Schwartzenberg K. Structure and function of nucleoside hydrolases from Physcomitrella patens and maize catalyzing the hydrolysis of purine, pyrimidine, and cytokinin ribosides. PLANT PHYSIOLOGY 2013; 163:1568-83. [PMID: 24170203 PMCID: PMC3850210 DOI: 10.1104/pp.113.228775] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We present a comprehensive characterization of the nucleoside N-ribohydrolase (NRH) family in two model plants, Physcomitrella patens (PpNRH) and maize (Zea mays; ZmNRH), using in vitro and in planta approaches. We identified two NRH subclasses in the plant kingdom; one preferentially targets the purine ribosides inosine and xanthosine, while the other is more active toward uridine and xanthosine. Both subclasses can hydrolyze plant hormones such as cytokinin ribosides. We also solved the crystal structures of two purine NRHs, PpNRH1 and ZmNRH3. Structural analyses, site-directed mutagenesis experiments, and phylogenetic studies were conducted to identify the residues responsible for the observed differences in substrate specificity between the NRH isoforms. The presence of a tyrosine at position 249 (PpNRH1 numbering) confers high hydrolase activity for purine ribosides, while an aspartate residue in this position confers high activity for uridine. Bud formation is delayed by knocking out single NRH genes in P. patens, and under conditions of nitrogen shortage, PpNRH1-deficient plants cannot salvage adenosine-bound nitrogen. All PpNRH knockout plants display elevated levels of certain purine and pyrimidine ribosides and cytokinins that reflect the substrate preferences of the knocked out enzymes. NRH enzymes thus have functions in cytokinin conversion and activation as well as in purine and pyrimidine metabolism.
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Li L, Song J, Kalt W, Forney C, Tsao R, Pinto D, Chisholm K, Campbell L, Fillmore S, Li X. Quantitative proteomic investigation employing stable isotope labeling by peptide dimethylation on proteins of strawberry fruit at different ripening stages. J Proteomics 2013; 94:219-39. [DOI: 10.1016/j.jprot.2013.09.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/27/2013] [Accepted: 09/12/2013] [Indexed: 02/01/2023]
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Chaturvedi P, Ischebeck T, Egelhofer V, Lichtscheidl I, Weckwerth W. Cell-specific analysis of the tomato pollen proteome from pollen mother cell to mature pollen provides evidence for developmental priming. J Proteome Res 2013; 12:4892-903. [PMID: 23731163 DOI: 10.1021/pr400197p] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Tomato is a globally important crop grown and consumed worldwide. Its reproductive activity is highly sensitive to environmental fluctuations, for instance temperature and drought. Here, pollen development is one of the most decisive processes. The present study aims for the identification of cell-specific proteins during pollen developmental stages of tomato. We have setup a protocol for stage-specific pollen isolation including microsporocytes (pollen mother cells), tetrads, microspores, polarized microspores, and mature pollen. Proteins were extracted using phenol and prefractionated using SDS-PAGE followed by protein digestion, peptide extraction, and desalting. Identification and quantification of proteins were performed using nanoHPLC coupled to LTQ-Orbitrap-MS. In total, 1821 proteins were identified. Most of these proteins were classified based on their homology and designated functions of orthologs. Cluster and principal components analysis revealed stage-specific proteins and demonstrated that pollen development of tomato is a highly controlled sequential process at the proteome level. Intermediate stages such as tetrad and polarized microspore are clearly distinguished by different functionality compared to other stages. From the predicted functions, energy-related proteins are increased during the later stages of development, which indicates that pollen germination depends upon presynthesized proteins in mature pollen. In contrast, heat stress-related proteins are highly abundant in very early developmental stages, suggesting a dominant role in stress protection. Taken together, the data provide a first cell-specific protein reference set for tomato pollen development from pollen mother cells to the mature pollen and give evidence for developmentally controlled processes that might help to prepare the cells for specific developmental programs and environmental stresses.
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Affiliation(s)
- Palak Chaturvedi
- Department of Molecular Systems Biology, Faculty of Sciences, University of Vienna , Althanstrasse 14, A-1090, Vienna, Austria
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Abstract
Adenosine kinase (ADK; EC 2.7.1.20) is an evolutionarily conserved phosphotransferase that converts the purine ribonucleoside adenosine into 5'-adenosine-monophosphate. This enzymatic reaction plays a fundamental role in determining the tone of adenosine, which fulfills essential functions as a homeostatic and metabolic regulator in all living systems. Adenosine not only activates specific signaling pathways by activation of four types of adenosine receptors but it is also a primordial metabolite and regulator of biochemical enzyme reactions that couple to bioenergetic and epigenetic functions. By regulating adenosine, ADK can thus be identified as an upstream regulator of complex homeostatic and metabolic networks. Not surprisingly, ADK dysfunction is involved in several pathologies, including diabetes, epilepsy, and cancer. Consequently, ADK emerges as a rational therapeutic target, and adenosine-regulating drugs have been tested extensively. In recent attempts to improve specificity of treatment, localized therapies have been developed to augment adenosine signaling at sites of injury or pathology; those approaches include transplantation of stem cells with deletions of ADK or the use of gene therapy vectors to downregulate ADK expression. More recently, the first human mutations in ADK have been described, and novel findings suggest an unexpected role of ADK in a wider range of pathologies. ADK-regulating strategies thus represent innovative therapeutic opportunities to reconstruct network homeostasis in a multitude of conditions. This review will provide a comprehensive overview of the genetics, biochemistry, and pharmacology of ADK and will then focus on pathologies and therapeutic interventions. Challenges to translate ADK-based therapies into clinical use will be discussed critically.
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Affiliation(s)
- Detlev Boison
- Legacy Research Institute, 1225 NE 16th Ave, Portland, OR 97202, USA.
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Farrow SC, Emery RJN. Concurrent profiling of indole-3-acetic acid, abscisic acid, and cytokinins and structurally related purines by high-performance-liquid-chromatography tandem electrospray mass spectrometry. PLANT METHODS 2012; 8:42. [PMID: 23061971 PMCID: PMC3583190 DOI: 10.1186/1746-4811-8-42] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 10/08/2012] [Indexed: 05/17/2023]
Abstract
UNLABELLED BACKGROUND Cytokinins (CKs) are a group of plant growth regulators that are involved in several plant developmental processes. Despite the breadth of knowledge surrounding CKs and their diverse functions, much remains to be discovered about the full potential of CKs, including their relationship with the purine salvage pathway, and other phytohormones. The most widely used approach to query unknown facets of CK biology utilized functional genomics coupled with CK metabolite assays and screening of CK associated phenotypes. There are numerous different types of assays for determining CK quantity, however, none of these methods screen for the compendium of metabolites that are necessary for elucidating all roles, including purine salvage pathway enzymes in CK metabolism, and CK cross-talk with other phytohormones. Furthermore, all published analytical methods have drawbacks ranging from the required use of radiolabelled compounds, or hazardous derivatization reagents, poor sensitivity, lack of resolution between CK isomers and lengthy run times. RESULTS In this paper, a method is described for the concurrent extraction, purification and analysis of several CKs (freebases, ribosides, glucosides, nucleotides), purines (adenosine monophosphate, inosine, adenosine, and adenine), indole-3-acetic acid, and abscisic acid from hundred-milligram (mg) quantities of Arabidopsis thaliana leaf tissue. This method utilizes conventional Bieleski solvents extraction, solid phase purification, and is unique because of its diverse range of detectable analytes, and implementation of a conventional HPLC system with a fused core column that enables good sensitivity without the requirement of a UHPLC system. Using this method we were able to resolve CKs about twice as fast as our previous method. Similarly, analysis of adenosine, indole-3-acetic acid, and abscisic acid, was comparatively rapid. A further enhancement of the method was the utilization of a QTRAP 5500 mass analyzer, which improved upon several aspects of our previous analytical method carried out on a Quattro mass analyzer. Notable improvements included much superior sensitivity, and number of analytes detectable within a single run. Limits of detection ranged from 2 pM for (9G)Z to almost 750 pM for indole-3-acetic acid. CONCLUSIONS This method is well suited for functional genomics platforms tailored to understanding CK metabolism, CK interrelationships with purine recycling and associated hormonal cross-talk.
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Affiliation(s)
- Scott C Farrow
- Biology Department, Trent University, Peterborough, ON, K9J 7B8, Canada
- Present Address: Department of Biological Sciences, University of Calgary, 2500 University Drive N.W., University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - RJ Neil Emery
- Biology Department, Trent University, Peterborough, ON, K9J 7B8, Canada
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Gilkerson J, Perez-Ruiz JM, Chory J, Callis J. The plastid-localized pfkB-type carbohydrate kinases FRUCTOKINASE-LIKE 1 and 2 are essential for growth and development of Arabidopsis thaliana. BMC PLANT BIOLOGY 2012; 12:102. [PMID: 22770232 PMCID: PMC3409070 DOI: 10.1186/1471-2229-12-102] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 07/08/2012] [Indexed: 05/18/2023]
Abstract
BACKGROUND Transcription of plastid-encoded genes requires two different DNA-dependent RNA polymerases, a nuclear-encoded polymerase (NEP) and plastid-encoded polymerase (PEP). Recent studies identified two related pfkB-type carbohydrate kinases, named FRUCTOKINASE-LIKE PROTEIN (FLN1 and FLN2), as components of the thylakoid bound PEP complex in both Arabidopsis thaliana and Sinapis alba (mustard). Additional work demonstrated that RNAi-mediated reduction in FLN expression specifically diminished transcription of PEP-dependent genes. RESULTS Here, we report the characterization of Arabidopsis FLN knockout alleles to examine the contribution of each gene in plant growth, chloroplast development, and in mediating PEP-dependent transcription. We show that fln plants have severe phenotypes with fln1 resulting in an albino phenotype that is seedling lethal without a source of exogenous carbon. In contrast, fln2 plants display chlorosis prior to leaf expansion, but exhibit slow greening, remain autotrophic, can grow to maturity, and set viable seed. fln1 fln2 double mutant analysis reveals haplo-insufficiency, and fln1 fln2 plants have a similar, but more severe phenotype than either single mutant. Normal plastid development in both light and dark requires the FLNs, but surprisingly skotomorphogenesis is unaffected in fln seedlings. Seedlings genetically fln1-1 with dexamethasone-inducible FLN1-HA expression at germination are phenotypically indistinguishable from wild-type. Induction of FLN-HA after 24 hours of germination cannot rescue the mutant phenotype, indicating that the effects of loss of FLN are not always reversible. Examination of chloroplast gene expression in fln1-1 and fln2-1 by qRT-PCR reveals that transcripts of PEP-dependent genes were specifically reduced compared to NEP-dependent genes in both single mutants. CONCLUSIONS Our results demonstrate that each FLN protein contributes to wild type growth, and acting additively are absolutely essential for plant growth and development.
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Affiliation(s)
- Jonathan Gilkerson
- Department of Molecular and Cellular Biology, University of California, 1 Shields Avenue, Davis, CA, 95616, USA
- Plant Biology Graduate Group, University of California, Davis, CA, 95616, USA
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Juan Manuel Perez-Ruiz
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Joanne Chory
- Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Judy Callis
- Department of Molecular and Cellular Biology, University of California, 1 Shields Avenue, Davis, CA, 95616, USA
- Plant Biology Graduate Group, University of California, Davis, CA, 95616, USA
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Lee S, Doxey AC, McConkey BJ, Moffatt BA. Nuclear targeting of methyl-recycling enzymes in Arabidopsis thaliana is mediated by specific protein interactions. MOLECULAR PLANT 2012; 5:231-48. [PMID: 21976714 DOI: 10.1093/mp/ssr083] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase (SAHH) and adenosine kinase (ADK) act coordinately to recycle the by-product of these reactions, S-adenosylhomocysteine (SAH) that would otherwise competitively inhibit methyltransferase (MT) activities. Here, we report on investigations to understand how the SAH produced in the nucleus is metabolized by SAHH and ADK. Localization analyses using green fluorescent fusion proteins demonstrated that both enzymes are capable of localizing to the cytoplasm and the nucleus, although no obvious nuclear localization signal was found in their sequences. Deletion analysis revealed that a 41-amino-acid segment of SAHH (Gly(150)-Lys(190)) is required for nuclear targeting of this enzyme. This segment is surface exposed, shows unique sequence conservation patterns in plant SAHHs, and possesses additional features of protein-protein interaction motifs. ADK and SAHH interact in Arabidopsis via this segment and also interact with an mRNA cap MT. We propose that the targeting of this complex is directed by the nuclear localization signal of the MT; other MTs may similarly target SAHH/ADK to other subcellular compartments to ensure uninterrupted transmethylation.
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Affiliation(s)
- Sanghyun Lee
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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Schoor S, Farrow S, Blaschke H, Lee S, Perry G, von Schwartzenberg K, Emery N, Moffatt B. Adenosine kinase contributes to cytokinin interconversion in Arabidopsis. PLANT PHYSIOLOGY 2011; 157:659-72. [PMID: 21803861 PMCID: PMC3192563 DOI: 10.1104/pp.111.181560] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Purine salvage enzymes have been implicated, but not proven, to be involved in the interconversion of cytokinin (CK) bases, ribosides, and nucleotides. Here, we use Arabidopsis (Arabidopsis thaliana) lines silenced in adenosine kinase (ADK) expression to understand the contributions of this enzyme activity to in vivo CK metabolism. Both small interfering RNA- and artificial microRNA-mediated silencing of ADK led to impaired root growth, small, crinkled rosette leaves, and reduced apical dominance. Further examination of ADK-deficient roots and leaves revealed their irregular cell division. Root tips had uneven arrangements of root cap cells, reduced meristem sizes, and enlarged cells in the elongation zone; rosette leaves exhibited decreased cell size but increased cell abundance. Expression patterns of the cyclinB1;1::β-glucuronidase and Arabidopsis Response Regulator5::β-glucuronidase reporters in the ADK-deficient background were consistent with altered cell division and an increase in CK activity, respectively. In vivo feeding of ADK-deficient leaves with radiolabeled CK ribosides of isopentenyladenosine and zeatin showed a decreased flux into the corresponding CK nucleotides. Comprehensive high-performance liquid chromatography-tandem mass spectrometry analysis detected significantly higher levels of active CK ribosides in both sense ADK and artificial microADK. Taken together, these metabolic and phenotypic analyses of ADK-deficient lines indicate that ADK contributes to CK homeostasis in vivo.
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40
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Ding C, You J, Wang S, Liu Z, Li G, Wang Q, Ding Y. A proteomic approach to analyze nitrogen- and cytokinin-responsive proteins in rice roots. Mol Biol Rep 2011; 39:1617-26. [PMID: 21607616 DOI: 10.1007/s11033-011-0901-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 05/17/2011] [Indexed: 01/24/2023]
Abstract
Nitrogen plays a central role in rice growth and development because it modulates a wide variety of processes, including cytokinin (CK) metabolism. CK-mediated signaling is also related to nitrogen metabolism. The functional relation between nitrogen and CK are extremely complex and unclear. In this study, a comparative proteomic analysis was carried out to analyze proteins regulated by nitrogen and CK in rice roots. Proteins extracted from rice roots are separated by two-dimensional polyacrylamide gel electrophoresis. Thirty-two protein spots that expressed similarly by nitrogen and CK treatments are selected for identification by mass spectrometry. Of these spots, 28 are successfully identified. These proteins were categorized into classes related to energy, metabolism, disease/defense, protein degradation, signal transduction, transposons, and unclear classification. Energy gives the largest functional category, suggesting that the glycolysis (two enzymes detected) and tricarboxylic acid cycle (six enzymes detected) are accurately regulated by nitrogen and CK, thus promoting the synthesis of amino acid. The identification of novel proteins provides new insights into the coordination of nitrogen and CK in rice. The possible role of these proteins is discussed.
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Affiliation(s)
- Chengqiang Ding
- College of Agronomy, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
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41
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Huerta-Ocampo JA, León-Galván MF, Ortega-Cruz LB, Barrera-Pacheco A, De León-Rodríguez A, Mendoza-Hernández G, de la Rosa APB. Water stress induces up-regulation of DOF1 and MIF1 transcription factors and down-regulation of proteins involved in secondary metabolism in amaranth roots (Amaranthus hypochondriacus L.). PLANT BIOLOGY (STUTTGART, GERMANY) 2011; 13:472-82. [PMID: 21489098 DOI: 10.1111/j.1438-8677.2010.00391.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Roots are the primary sites of water stress perception in plants. The aim of this work was to study differential expression of proteins and transcripts in amaranth roots (Amaranthus hypochondriacus L.) when the plants were grown under drought stress. Changes in protein abundance within the roots were examined using two-dimensional electrophoresis and LC/ESI-MS/MS, and the differential expression of transcripts was evaluated with suppression subtractive hybridisation (SSH). Induction of drought stress decreased relative water content in leaves and increased solutes such as proline and total soluble sugars in roots. Differentially expressed proteins such as SOD(Cu-Zn) , heat shock proteins, signalling-related and glycine-rich proteins were identified. Up-regulated transcripts were those related to defence, stress, signalling (Ser, Tyr-kinases and phosphatases) and water transport (aquaporins and nodulins). More noteworthy was identification of the transcription factors DOF1, which has been related to several plant-specific biological processes, and MIF1, whose constitutive expression has been related to root growth reduction and dwarfism. The down-regulated genes/proteins identified were related to cell differentiation (WOX5A) and secondary metabolism (caffeic acid O-methyltransferase, isoflavone reductase-like protein and two different S-adenosylmethionine synthetases). Amaranth root response to drought stress appears to involve a coordinated response of osmolyte accumulation, up-regulation of proteins that control damage from reactive oxygen species, up-regulation of a family of heat shock proteins that stabilise other proteins and up-regulation of transcription factors related to plant growth control.
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Affiliation(s)
- J A Huerta-Ocampo
- Molecular Biology Division, Institute for Scientific and Technological Research of San Luis Potosí, San Luis Potosí, México
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Pandey A, Rajamani U, Verma J, Subba P, Chakraborty N, Datta A, Chakraborty S, Chakraborty N. Identification of extracellular matrix proteins of rice (Oryza sativa L.) involved in dehydration-responsive network: a proteomic approach. J Proteome Res 2010; 9:3443-64. [PMID: 20433195 DOI: 10.1021/pr901098p] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Water-deficit or dehydration impairs almost all physiological processes and greatly influences the geographical distribution of many crop species. It has been postulated that higher plants rely mostly on induction mechanisms to maintain cellular integrity during stress conditions. Plant cell wall or extracellular matrix (ECM) forms an important conduit for signal transduction between the apoplast and symplast and acts as front-line defense, thereby playing a key role in cell fate decision under various stress conditions. To better understand the molecular mechanism of dehydration response in plants, four-week-old rice seedlings were subjected to progressive dehydration by withdrawing water and the changes in the ECM proteome were examined using two-dimensional gel electrophoresis. Dehydration-responsive temporal changes revealed 192 proteins that change their intensities by more than 2.5-fold, at one or more time points during dehydration. The proteomic analysis led to the identification of about 100 differentially regulated proteins presumably involved in a variety of functions, including carbohydrate metabolism, cell defense and rescue, cell wall modification, cell signaling and molecular chaperones, among others. The differential rice proteome was compared with the dehydration-responsive proteome data of chickpea and maize. The results revealed an evolutionary divergence in the dehydration response as well as organ specificity, with few conserved proteins. The differential expression of the candidate proteins, in conjunction with previously reported results, may provide new insight into the underlying mechanisms of the dehydration response in plants. This may also facilitate the targeted alteration of metabolic routes in the cell wall for agricultural and industrial exploitation.
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Affiliation(s)
- Aarti Pandey
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi-110067, India
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Möhlmann T, Bernard C, Hach S, Ekkehard Neuhaus H. Nucleoside transport and associated metabolism. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12 Suppl 1:26-34. [PMID: 20712618 DOI: 10.1111/j.1438-8677.2010.00351.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Nucleosides are intermediates of nucleotide metabolism. Nucleotide de novo synthesis generates the nucleoside monophosphates AMP and UMP, which are further processed to all purine and pyrimidine nucleotides involved in multiple cellular reactions, including the synthesis of nucleic acids. Catabolism of these substances results in the formation of nucleosides, which are further degraded by nucleoside hydrolase to nucleobases. Both nucleosides and nucleobases can be exchanged between cells and tissues through multiple isoforms of corresponding transport proteins. After uptake into a cell, nucleosides and nucleobases can undergo salvage reactions or catabolism. Whereas energy is preserved by salvage pathway reactions, catabolism liberates ammonia, which is then incorporated into amino acids. Keeping the balance between nitrogen consumption during nucleotide de novo synthesis and ammonia liberation by nucleotide catabolism is essential for correct plant development. Senescence and seed germination represent situations in plant development where marked fluctuations in nucleotide pools occur. Furthermore, extracellular nucleotide metabolism has become an immensely interesting research topic. In addition, selected aspects of nucleoside transport in yeast, protists and humans are discussed.
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Affiliation(s)
- T Möhlmann
- Abteilung Pflanzenphysiologie, Fachbereich Biologie, Technische Universität Kaiserslautern, Kaiserslautern, Germany.
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The interaction between geminivirus pathogenicity proteins and adenosine kinase leads to increased expression of primary cytokinin-responsive genes. Virology 2010; 402:238-47. [PMID: 20399479 DOI: 10.1016/j.virol.2010.03.023] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 02/27/2010] [Accepted: 03/13/2010] [Indexed: 11/24/2022]
Abstract
Pathogenicity proteins (AL2/C2) of begomo- and curtoviruses suppress silencing through inhibition of the methyl cycle, as a consequence of inhibiting adenosine kinase (ADK). ADK phosphorylates cytokinin nucleosides, helping maintain a pool of bioactive cytokinins through interconversion of free-bases, nucleosides and nucleotides. We provide evidence that inhibiting ADK affects expression of primary cytokinin-responsive genes. Specifically, we demonstrate increased activity of a primary cytokinin-responsive promoter in adk mutant Arabidopsis plants, and in response to silencing ADK expression or inhibiting ADK activity in transient assays. Similar changes in expression are observed in geminivirus infected tissue and when AL2/C2 are over-expressed. Increased cytokinin-responsive promoter activity may therefore be a consequence of an ADK/AL2/C2 interaction. Application of exogenous cytokinin increases susceptibility to geminivirus infection, characterized by a reduced mean latent period and enhanced viral replication. Thus, ADK appears to be a high value target of geminiviruses that includes increasing expression of primary cytokinin-responsive genes.
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45
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Babosha AV. Regulation of resistance and susceptibility in wheat-powdery mildew pathosystem with exogenous cytokinins. JOURNAL OF PLANT PHYSIOLOGY 2009; 166:1892-903. [PMID: 19592133 DOI: 10.1016/j.jplph.2009.05.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 05/21/2009] [Accepted: 05/28/2009] [Indexed: 05/17/2023]
Abstract
Dose-response relationship between resistance of wheat seedlings (Triticum aestivum, cultivar Zarya) to Erysiphe graminis f. sp. tritici Marchal. (Syn. Blumeria graminis), a causal organism of wheat powdery mildew and exogenous zeatin has been investigated. Two-week-old seedlings were inoculated with the pathogen. Zeatin or zeatinriboside were added to the nutrient solution immediately after inoculation. The dose-response curve of cytokinin in the most cases was multiphasic, with peaks of increased susceptibility occurring at 0.25-1.5 and 1.5-9microM cytokinin, separated by a region of increased resistance at 0.5-3microM cytokinin. The change in mineral nutrition or simultaneous treatment with thidiazuron revealed alterations of the dose-response curve ranging from a curve with maximum of resistance to a curve with maximum of susceptibility. Both multiphase nature of dose-response and its variability were proposed as possible explanations for earlier observed discrepancies in experimental data on modification of disease resistance by cytokinins. A mathematical model for two metabolic processes with substrate inhibition connected in-series was suggested to explain the multiphase dose-response. In this model, the product of the first reaction was used as substrate for the second reaction. Numerical experiments showed the changes in the shape of dose-response curve with changes in parameters dependent of cytokinin metabolism.
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Affiliation(s)
- Alexander V Babosha
- N.V. Tsitsin Main Botanical Garden RAS, Botanicheskaya str. 4, 127276 Moscow, Russian Federation.
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Ogawa T, Nishimura K, Aoki T, Takase H, Tomizawa KI, Ashida H, Yokota A. A phosphofructokinase B-type carbohydrate kinase family protein, NARA5, for massive expressions of plastid-encoded photosynthetic genes in Arabidopsis. PLANT PHYSIOLOGY 2009; 151:114-28. [PMID: 19587101 PMCID: PMC2736000 DOI: 10.1104/pp.109.139683] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
To date, there have been no reports on screening for mutants defective in the massive accumulation of Rubisco in higher plants. Here, we describe a screening method based on the toxic accumulation of ammonia in the presence of methionine sulfoximine, a specific inhibitor of glutamine synthetase, during photorespiration initiated by the oxygenase reaction of Rubisco in Arabidopsis (Arabidopsis thaliana). Five recessive mutants with decreased amounts of Rubisco were identified and designated as nara mutants, as they contained a mutation in genes necessary for the achievement of Rubisco accumulation. The nara5-1 mutant showed markedly lower levels of plastid-encoded photosynthetic proteins, including Rubisco. Map-based cloning revealed that NARA5 encoded a chloroplast phosphofructokinase B-type carbohydrate kinase family protein of unknown function. The NARA5 protein fused to green fluorescent protein localized in chloroplasts. We conducted expression analyses of photosynthetic genes during light-induced greening of etiolated seedlings of nara5-1 and the T-DNA insertion mutant, nara5-2. Our results strongly suggest that NARA5 is indispensable for hyperexpression of photosynthetic genes encoded in the plastid genome, particularly rbcL.
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Affiliation(s)
- Taro Ogawa
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan
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Zou J, Song L, Zhang W, Wang Y, Ruan S, Wu WH. Comparative proteomic analysis of Arabidopsis mature pollen and germinated pollen. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2009; 51:438-55. [PMID: 19508356 DOI: 10.1111/j.1744-7909.2009.00823.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Proteomic analysis was applied to generating the map of Arabidopsis mature pollen proteins and analyzing the differentially expressed proteins that are potentially involved in the regulation of Arabidopsis pollen germination. By applying 2-D electrophoresis and silver staining, we resolved 499 and 494 protein spots from protein samples extracted from pollen grains and pollen tubes, respectively. Using the matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, we identified 189 distinct proteins from 213 protein spots expressed in mature pollen or pollen tubes, and 75 new identified proteins that had not been reported before in research into the Arabidopsis pollen proteome. Comparative analysis revealed that 40 protein spots exhibit reproducible significant changes between mature pollen and pollen tubes. And 21 proteins from 17 downregulated and six upregulated protein spots were identified. Functional category analysis indicated that these differentially expressed proteins mainly involved in signaling, cellular structure, transport, defense/stress responses, transcription, metabolism, and energy production. The patterns of changes at protein level suggested the important roles for energy metabolism-related proteins in pollen tube growth, accompanied by the activation of the stress response pathway and modifications to the cell wall.
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Affiliation(s)
- Junjie Zou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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48
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An adenosine kinase exists in Xanthomonas campestris pathovar campestris and is involved in extracellular polysaccharide production, cell motility, and virulence. J Bacteriol 2009; 191:3639-48. [PMID: 19329636 DOI: 10.1128/jb.00009-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adenosine kinase (ADK) is a purine salvage enzyme and a typical housekeeping enzyme in eukaryotes which catalyzes the phosphorylation of adenosine to form AMP. Since prokaryotes synthesize purines de novo and no endogenous ADK activity is detectable in Escherichia coli, ADK has long been considered to be rare in bacteria. To date, only two prokaryotes, both of which are gram-positive bacteria, have been reported to contain ADK. Here we report that the gram-negative bacterium Xanthomonas campestris pathovar campestris, the causal agent of black rot of crucifers, possesses a gene (designated adk(Xcc)) encoding an ADK (named ADK(Xcc)), and we demonstrate genetically that the ADK(Xcc) is involved in extracellular polysaccharide (EPS) production, cell motility, and pathogenicity of X. campestris pv. campestris. adk(Xcc) was overexpressed as a His(6)-tagged protein in E. coli, and the purified His(6)-tagged protein exhibited ADK activity. Mutation of adk(Xcc) did not affect bacterial growth in rich and minimal media but led to an accumulation of intracellular adenosine and diminutions of intracellular ADK activity and ATP level, as well as EPS. The adk(Xcc) mutant displayed significant reductions in bacterial growth and virulence in the host plant.
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Jung B, Flörchinger M, Kunz HH, Traub M, Wartenberg R, Jeblick W, Neuhaus HE, Möhlmann T. Uridine-ribohydrolase is a key regulator in the uridine degradation pathway of Arabidopsis. THE PLANT CELL 2009; 21:876-91. [PMID: 19293370 PMCID: PMC2671717 DOI: 10.1105/tpc.108.062612] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 02/03/2009] [Accepted: 03/03/2009] [Indexed: 05/17/2023]
Abstract
Nucleoside degradation and salvage are important metabolic pathways but hardly understood in plants. Recent work on human pathogenic protozoans like Leishmania and Trypanosoma substantiates an essential function of nucleosidase activity. Plant nucleosidases are related to those from protozoans and connect the pathways of nucleoside degradation and salvage. Here, we describe the cloning of such an enzyme from Arabidopsis thaliana, Uridine-Ribohydrolase 1 (URH1) and the characterization by complementation of a yeast mutant. Furthermore, URH1 was synthesized as a recombinant protein in Escherichia coli. The pure recombinant protein exhibited highest hydrolase activity for uridine, followed by inosine and adenosine, the corresponding K(m) values were 0.8, 1.4, and 0.7 mM, respectively. In addition, URH1 was able to cleave the cytokinin derivative isopentenyladenine-riboside. Promoter beta-glucuronidase fusion studies revealed that URH1 is mainly transcribed in the vascular cells of roots and in root tips, guard cells, and pollen. Mutants expressing the Arabidopsis enzyme or the homolog from rice (Oryza sativa) exhibit resistance toward toxic fluorouridine, fluorouracil, and fluoroorotic acid, providing clear evidence for a pivotal function of URH1 as regulative in pyrimidine degradation. Moreover, mutants with increased and decreased nucleosidase activity are delayed in germination, indicating that this enzyme activity must be well balanced in the early phase of plant development.
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Affiliation(s)
- Benjamin Jung
- Abteilung Pflanzenphysiologie, Fachbereich Biologie, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
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Vannoni D, Giglioni S, Santoro A, Aceto E, Marinello E, Leoncini R. A kinetic study of the rat liver adenosine kinase reverse reaction. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 27:872-5. [PMID: 18600555 DOI: 10.1080/15257770802146544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Adenosine kinase is an enzyme catalyzing the reaction: adenosine + ATP --> AMP + ADP. We studied some biochemical properties not hitherto investigated and demonstrated that the reaction can be easily reversed when coupled with adenosine deaminase, which transforms adenosine into inosine and ammonia. The overall reaction is: AMP + ADP --> ATP + inosine + NH(3). The exoergonic ADA reaction shifts the equilibrium and fills the energy gap necessary for synthesis of ATP. This reaction could be used by cells under particular conditions of energy deficiency and, together with myokinase activity, may help to restore physiological ATP levels.
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Affiliation(s)
- D Vannoni
- Dipartimento di Medicina Interna, Sc. Endocrino-Metaboliche e Biochimica, Università di Siena, Siena, Italy.
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