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Soltabayeva A, Kurmanbayeva A, Bekturova A, Oshanova D, Nurbekova Z, Srivastava S, Standing D, Zdunek-Zastocka E, Sagi M. Endogenous ureides are employed as a carbon source in Arabidopsis plants exposed to carbon starvation conditions. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 344:112108. [PMID: 38705480 DOI: 10.1016/j.plantsci.2024.112108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 04/01/2024] [Accepted: 04/23/2024] [Indexed: 05/07/2024]
Abstract
Ureides, the degraded products of purine catabolism in Arabidopsis, have been shown to act as antioxidant and nitrogen sources. Herein we elucidate purine degraded metabolites as a carbon source using the Arabidopsis Atxdh1, Ataln, and Ataah knockout (KO) mutants vis-à-vis wild-type (WT) plants. Plants were grown under short-day conditions on agar plates containing half-strength MS medium with or without 1% sucrose. Notably, the absence of sucrose led to diminished biomass accumulation in both shoot and root tissues of the Atxdh1, Ataln, and Ataah mutants, while no such effect was observed in WT plants. Moreover, the application of sucrose resulted in a reduction of purine degradation metabolite levels, specifically xanthine and allantoin, predominantly within the roots of WT plants. Remarkably, an increase in proteins associated with the purine degradation pathway was observed in WT plants in the presence of sucrose. Lower glyoxylate levels in the roots but not in the shoot of the Atxdh1 mutant in comparison to WT, were observed under sucrose limitation, and improved by sucrose application in root, indicating that purine degradation provided glyoxylate in the root. Furthermore, the deficit of purine-degraded metabolites in the roots of mutants subjected to carbon starvation was partially mitigated through allantoin application. Collectively, these findings signify that under conditions of sucrose limitation and short-day growth, purines are primarily remobilized within the root system to augment the availability of ureides, serving as an additional carbon (as well as nitrogen) source to support plant growth.
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Affiliation(s)
- Aigerim Soltabayeva
- Biology Department, School of Science and Humanities, Nazarbayev University, Astana Z05H0P9, Kazakhstan
| | - Assylay Kurmanbayeva
- Department of Biotechnology and Microbiology, L.N. Gumilyov Eurasian National University, Astana 010000, Kazakhstan
| | - Aizat Bekturova
- The Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Dinara Oshanova
- The Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Zhadyrassyn Nurbekova
- The Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Sudhakar Srivastava
- Jacob Blaustein Center for Scientific Cooperation, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Dominic Standing
- The Albert Katz Department of Dryland Biotechnologies, French Associates Institute for Agriculture and Biotechnology of Dryland, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Edyta Zdunek-Zastocka
- Warsaw Univ Life Sci, Inst Biol, Dept Biochem & Microbiol, SGGW, Nowoursynowska 159, Warsaw PL-02776, Poland
| | - Moshe Sagi
- The Albert Katz Department of Dryland Biotechnologies, French Associates Institute for Agriculture and Biotechnology of Dryland, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel; Katif Research Center for Development of Coastal Deserts, Netivot 87710, Israel.
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Wanke A, van Boerdonk S, Mahdi LK, Wawra S, Neidert M, Chandrasekar B, Saake P, Saur IML, Derbyshire P, Holton N, Menke FLH, Brands M, Pauly M, Acosta IF, Zipfel C, Zuccaro A. A GH81-type β-glucan-binding protein enhances colonization by mutualistic fungi in barley. Curr Biol 2023; 33:5071-5084.e7. [PMID: 37977140 DOI: 10.1016/j.cub.2023.10.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 08/06/2023] [Accepted: 10/25/2023] [Indexed: 11/19/2023]
Abstract
Cell walls are important interfaces of plant-fungal interactions, acting as robust physical and chemical barriers against invaders. Upon fungal colonization, plants deposit phenolics and callose at the sites of fungal penetration to prevent further fungal progression. Alterations in the composition of plant cell walls significantly impact host susceptibility. Furthermore, plants and fungi secrete glycan hydrolases acting on each other's cell walls. These enzymes release various sugar oligomers into the apoplast, some of which activate host immunity via surface receptors. Recent characterization of cell walls from plant-colonizing fungi has emphasized the abundance of β-glucans in different cell wall layers, which makes them suitable targets for recognition. To characterize host components involved in immunity against fungi, we performed a protein pull-down with the biotinylated β-glucan laminarin. Thereby, we identified a plant glycoside hydrolase family 81-type glucan-binding protein (GBP) as a β-glucan interactor. Mutation of GBP1 and its only paralog, GBP2, in barley led to decreased colonization by the beneficial root endophytes Serendipita indica and S. vermifera, as well as the arbuscular mycorrhizal fungus Rhizophagus irregularis. The reduction of colonization was accompanied by enhanced responses at the host cell wall, including an extension of callose-containing cell wall appositions. Moreover, GBP mutation in barley also reduced fungal biomass in roots by the hemibiotrophic pathogen Bipolaris sorokiniana and inhibited the penetration success of the obligate biotrophic leaf pathogen Blumeria hordei. These results indicate that GBP1 is involved in the establishment of symbiotic associations with beneficial fungi-a role that has potentially been appropriated by barley-adapted pathogens.
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Affiliation(s)
- Alan Wanke
- Institute for Plant Sciences, University of Cologne, Cologne, Germany; Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Sarah van Boerdonk
- Institute for Plant Sciences, University of Cologne, Cologne, Germany; Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Lisa Katharina Mahdi
- Institute for Plant Sciences, University of Cologne, Cologne, Germany; Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Stephan Wawra
- Institute for Plant Sciences, University of Cologne, Cologne, Germany
| | - Miriam Neidert
- Institute for Plant Sciences, University of Cologne, Cologne, Germany
| | - Balakumaran Chandrasekar
- Institute for Plant Sciences, University of Cologne, Cologne, Germany; Cluster of Excellence on Plant Sciences (CEPLAS), Cologne, Germany
| | - Pia Saake
- Institute for Plant Sciences, University of Cologne, Cologne, Germany; Cluster of Excellence on Plant Sciences (CEPLAS), Cologne, Germany
| | - Isabel M L Saur
- Institute for Plant Sciences, University of Cologne, Cologne, Germany; Cluster of Excellence on Plant Sciences (CEPLAS), Cologne, Germany
| | - Paul Derbyshire
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Nicholas Holton
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Frank L H Menke
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK
| | - Mathias Brands
- Institute for Plant Sciences, University of Cologne, Cologne, Germany
| | - Markus Pauly
- Institute of Plant Cell Biology and Biotechnology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany; Cluster of Excellence on Plant Sciences (CEPLAS), Düsseldorf, Germany
| | - Ivan F Acosta
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Cyril Zipfel
- The Sainsbury Laboratory, University of East Anglia, Norwich, UK; Institute of Plant and Microbial Biology, University of Zurich, and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Alga Zuccaro
- Institute for Plant Sciences, University of Cologne, Cologne, Germany; Cluster of Excellence on Plant Sciences (CEPLAS), Cologne, Germany.
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Busoms S, Pérez-Martín L, Terés J, Huang XY, Yant L, Tolrà R, Salt DE, Poschenrieder C. Combined genomics to discover genes associated with tolerance to soil carbonate. PLANT, CELL & ENVIRONMENT 2023; 46:3986-3998. [PMID: 37565316 DOI: 10.1111/pce.14691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023]
Abstract
Carbonate-rich soils limit plant performance and crop production. Previously, local adaptation to carbonated soils was detected in wild Arabidopsis thaliana accessions, allowing the selection of two demes with contrasting phenotypes: A1 (carbonate tolerant, c+) and T6 (carbonate sensitive, c-). Here, A1(c+) and T6(c - ) seedlings were grown hydroponically under control (pH 5.9) and bicarbonate conditions (10 mM NaHCO3 , pH 8.3) to obtain ionomic profiles and conduct transcriptomic analysis. In parallel, A1(c+) and T6(c - ) parental lines and their progeny were cultivated on carbonated soil to evaluate fitness and segregation patterns. To understand the genetic architecture beyond the contrasted phenotypes, a bulk segregant analysis sequencing (BSA-Seq) was performed. Transcriptomics revealed 208 root and 2503 leaf differentially expressed genes in A1(c+) versus T6(c - ) comparison under bicarbonate stress, mainly involved in iron, nitrogen and carbon metabolism, hormones and glycosylates biosynthesis. Based on A1(c+) and T6(c - ) genome contrasts and BSA-Seq analysis, 69 genes were associated with carbonate tolerance. Comparative analysis of genomics and transcriptomics discovered a final set of 18 genes involved in bicarbonate stress responses that may have relevant roles in soil carbonate tolerance.
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Affiliation(s)
- Silvia Busoms
- Department of Animal Biology, Plant Biology, and Ecology, Plant Physiology Laboratory, Bioscience Faculty, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laura Pérez-Martín
- Department of Animal Biology, Plant Biology, and Ecology, Plant Physiology Laboratory, Bioscience Faculty, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Joana Terés
- Department of Animal Biology, Plant Biology, and Ecology, Plant Physiology Laboratory, Bioscience Faculty, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Xin-Yuan Huang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Levi Yant
- Future Food Beacon of Excellence & School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Roser Tolrà
- Department of Animal Biology, Plant Biology, and Ecology, Plant Physiology Laboratory, Bioscience Faculty, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - David E Salt
- Future Food Beacon of Excellence & School of Biosciences, University of Nottingham, Sutton, UK
| | - Charlotte Poschenrieder
- Department of Animal Biology, Plant Biology, and Ecology, Plant Physiology Laboratory, Bioscience Faculty, Universitat Autònoma de Barcelona, Barcelona, Spain
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Kaur R, Chandra J, Varghese B, Keshavkant S. Allantoin: A Potential Compound for the Mitigation of Adverse Effects of Abiotic Stresses in Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:3059. [PMID: 37687306 PMCID: PMC10489999 DOI: 10.3390/plants12173059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023]
Abstract
Stress-induced alterations vary with the species of plants, the intensity and duration of the exposure, and stressors availability in nature or soil. Purine catabolism acts as an inherent defensive mechanism against various abiotic stresses and plays a pivotal role in the stress acclimatisation of plants. The intermediate metabolite of purine catabolism, allantoin, compensates for soil nitrogen deficiency due to the low carbon/nitrogen ratio, thereby maintaining nitrogen homeostasis and supporting plant growth and development. Allantoin accounts for 90% of the total nitrogenous compound in legumes, while it contributes only 15% in non-leguminous plants. Moreover, studies on a variety of plant species have reported the differential accumulation of allantoin in response to abiotic stresses, endowing allantoin as a stress modulator. Allantoin functions as signalling molecule to stimulate stress-responsive genes (P5CS; pyrroline-5-carboxylase synthase) and ROS (reactive oxygen species) scavenging enzymes (antioxidant). Moreover, it regulates cross-talk between the abscisic acid and jasmonic acid pathway, and maintains ion homeostasis by increasing the accumulation of putrescine and/or spermine, consequently enhancing the tolerance against stress conditions. Further, key enzymes of purine catabolism (xanthine dehydrogenase and allantoinase) have also been explored by constructing various knockdown/knockout mutant lines to decipher their impact on ROS-mediated oxidative injury in plants. Thus, it is established that allantoin serves as a regulatory signalling metabolite in stress protection, and therefore a lower accumulation of allantoin also reduces plant stress tolerance mechanisms. This review gives an account of metabolic regulation and the possible contribution of allantoin as a photo protectant, osmoprotectant, and nitrogen recycler to reduce abiotic-stress-induced impacts on plants.
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Affiliation(s)
- Rasleen Kaur
- School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur 492 010, India; (R.K.); (S.K.)
| | - Jipsi Chandra
- Center for Basic Sciences, Pt. Ravishankar Shukla University, Raipur 492 010, India;
| | - Boby Varghese
- Centre for Academic Success in Science and Engineering, University of KwaZulu-Natal, Durban 4001, South Africa
| | - S. Keshavkant
- School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur 492 010, India; (R.K.); (S.K.)
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Straube H, Straube J, Rinne J, Fischer L, Niehaus M, Witte CP, Herde M. An inosine triphosphate pyrophosphatase safeguards plant nucleic acids from aberrant purine nucleotides. THE NEW PHYTOLOGIST 2023; 237:1759-1775. [PMID: 36464781 DOI: 10.1111/nph.18656] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
In plants, inosine is enzymatically introduced in some tRNAs, but not in other RNAs or DNA. Nonetheless, our data show that RNA and DNA from Arabidopsis thaliana contain (deoxy)inosine, probably derived from nonenzymatic adenosine deamination in nucleic acids and usage of (deoxy)inosine triphosphate (dITP and ITP) during nucleic acid synthesis. We combined biochemical approaches, LC-MS, as well as RNA-Seq to characterize a plant INOSINE TRIPHOSPHATE PYROPHOSPHATASE (ITPA) from A. thaliana, which is conserved in many organisms, and investigated the sources of deaminated purine nucleotides in plants. Inosine triphosphate pyrophosphatase dephosphorylates deaminated nucleoside di- and triphosphates to the respective monophosphates. ITPA loss-of-function causes inosine di- and triphosphate accumulation in vivo and an elevated inosine and deoxyinosine content in RNA and DNA, respectively, as well as salicylic acid (SA) accumulation, early senescence, and upregulation of transcripts associated with immunity and senescence. Cadmium-induced oxidative stress and biochemical inhibition of the INOSINE MONOPHOSPHATE DEHYDROGENASE leads to more IDP and ITP in the wild-type (WT), and this effect is enhanced in itpa mutants, suggesting that ITP originates from ATP deamination and IMP phosphorylation. Inosine triphosphate pyrophosphatase is part of a molecular protection system in plants, preventing the accumulation of (d)ITP and its usage for nucleic acid synthesis.
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Affiliation(s)
- Henryk Straube
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover, 30419, Germany
| | - Jannis Straube
- Department of Molecular Plant Breeding, Leibniz Universität Hannover, Hannover, 30419, Germany
| | - Jannis Rinne
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover, 30419, Germany
| | - Lisa Fischer
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover, 30419, Germany
| | - Markus Niehaus
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover, 30419, Germany
| | - Claus-Peter Witte
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover, 30419, Germany
| | - Marco Herde
- Department of Molecular Nutrition and Biochemistry of Plants, Leibniz Universität Hannover, Hannover, 30419, Germany
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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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Prusty S, Sahoo RK, Nayak S, Poosapati S, Swain DM. Proteomic and Genomic Studies of Micronutrient Deficiency and Toxicity in Plants. PLANTS 2022; 11:plants11182424. [PMID: 36145825 PMCID: PMC9501179 DOI: 10.3390/plants11182424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 09/02/2022] [Accepted: 09/04/2022] [Indexed: 11/21/2022]
Abstract
Micronutrients are essential for plants. Their growth, productivity and reproduction are directly influenced by the supply of micronutrients. Currently, there are eight trace elements considered to be essential for higher plants: Fe, Zn, Mn, Cu, Ni, B, Mo, and Cl. Possibly, other essential elements could be discovered because of recent advances in nutrient solution culture techniques and in the commercial availability of highly sensitive analytical instrumentation for elemental analysis. Much remains to be learned about the physiology of micronutrient absorption, translocation and deposition in plants, and about the functions they perform in plant growth and development. With the recent advancements in the proteomic and molecular biology tools, researchers have attempted to explore and address some of these questions. In this review, we summarize the current knowledge of micronutrients in plants and the proteomic/genomic approaches used to study plant nutrient deficiency and toxicity.
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Affiliation(s)
- Suchismita Prusty
- Department of Biotechnology, Centurion University of Technology and Management, Bhubaneswar 752050, Odisha, India
| | - Ranjan Kumar Sahoo
- Department of Biotechnology, Centurion University of Technology and Management, Bhubaneswar 752050, Odisha, India
| | - Subhendu Nayak
- Division of Health Sciences, The Clorox Company, 210W Pettigrew Street, Durham, NC 27701, USA
| | - Sowmya Poosapati
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, CA 92093, USA
- Correspondence: (S.P.); (D.M.S.)
| | - Durga Madhab Swain
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, CA 92093, USA
- Correspondence: (S.P.); (D.M.S.)
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Yazdanpanah F, Willems LAJ, He H, Hilhorst HWM, Bentsink L. A Role for Allantoate Amidohydrolase (AtAAH) in the Germination of Arabidopsis thaliana Seeds. PLANT & CELL PHYSIOLOGY 2022; 63:1298-1308. [PMID: 35861030 PMCID: PMC9474941 DOI: 10.1093/pcp/pcac103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 06/10/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Seed dormancy is a very complex trait controlled by interactions between genetic and environmental factors. Nitrate is inversely correlated with seed dormancy in Arabidopsis. This is explained by the fact that seed dry storage (after-ripening) reduces the need for nitrogen for germination. When nitrate is absorbed by plants, it is first reduced to nitrite and then to ammonium for incorporation into amino acids, nucleic acids and chlorophyll. Previously, we showed that ALLANTOATE AMIDOHYDROLASE (AtAAH) transcripts are up-regulated in imbibed dormant seeds compared with after-ripened seeds. AAH is an enzyme in the uric acid catabolic pathway which catalyzes the hydrolysis of allantoate to yield CO2, NH3 and S-ureidoglycine. This pathway is the final stage of purine catabolism, and functions in plants and some bacteria to provide nitrogen, particularly when other nitrogen sources are depleted. Ataah mutant seeds are more dormant and accumulate high levels of allantoate, allantoin and urea, whereas energy-related metabolites and several amino acids are lower upon seed imbibition in comparison with Columbia-0. AtAAH expression could be detected during the early stages of seed development, with a transient increase around 8 d after pollination. AtAAH expression is the highest in mature pollen. The application of exogenous potassium nitrate can partly complement the higher dormancy phenotype of the Ataah mutant seeds, whereas other nitrogen sources cannot. Our results indicate that potassium nitrate does not specifically overcome the alleviated dormancy levels in Ataah mutant seeds, but promotes germination in general. Possible pathways by which AtAAH affects seed germination are discussed.
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Affiliation(s)
| | - Leo A J Willems
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, Wageningen 6708 PB, The Netherlands
| | | | - Henk W M Hilhorst
- Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, Wageningen 6708 PB, The Netherlands
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Enzymes and cellular interplay required for flux of fixed nitrogen to ureides in bean nodules. Nat Commun 2022; 13:5331. [PMID: 36088455 PMCID: PMC9464200 DOI: 10.1038/s41467-022-33005-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/29/2022] [Indexed: 11/27/2022] Open
Abstract
Tropical legumes transport fixed nitrogen in form of ureides (allantoin and allantoate) over long distances from the nodules to the shoot. Ureides are formed in nodules from purine mononucleotides by a partially unknown reaction network that involves bacteroid-infected and uninfected cells. Here, we demonstrate by metabolic analysis of CRISPR mutant nodules of Phaseolus vulgaris defective in either xanthosine monophosphate phosphatase (XMPP), guanosine deaminase (GSDA), the nucleoside hydrolases 1 and 2 (NSH1, NSH2) or xanthine dehydrogenase (XDH) that nodule ureide biosynthesis involves these enzymes and requires xanthosine and guanosine but not inosine monophosphate catabolism. Interestingly, promoter reporter analyses revealed that XMPP, GSDA and XDH are expressed in infected cells, whereas NSH1, NSH2 and the promoters of the downstream enzymes urate oxidase (UOX) and allantoinase (ALN) are active in uninfected cells. The data suggest a complex cellular organization of ureide biosynthesis with three transitions between infected and uninfected cells. Tropical legumes export fixed nitrogen from nodules as ureides. Here, the authors describe how ureides are produced by several biosynthetic enzymes in different nodule cell types and provide explanations for metabolic compartmentation.
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He J, Rössner N, Hoang MTT, Alejandro S, Peiter E. Transport, functions, and interaction of calcium and manganese in plant organellar compartments. PLANT PHYSIOLOGY 2021; 187:1940-1972. [PMID: 35235665 PMCID: PMC8890496 DOI: 10.1093/plphys/kiab122] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/02/2021] [Indexed: 05/05/2023]
Abstract
Calcium (Ca2+) and manganese (Mn2+) are essential elements for plants and have similar ionic radii and binding coordination. They are assigned specific functions within organelles, but share many transport mechanisms to cross organellar membranes. Despite their points of interaction, those elements are usually investigated and reviewed separately. This review takes them out of this isolation. It highlights our current mechanistic understanding and points to open questions of their functions, their transport, and their interplay in the endoplasmic reticulum (ER), vesicular compartments (Golgi apparatus, trans-Golgi network, pre-vacuolar compartment), vacuoles, chloroplasts, mitochondria, and peroxisomes. Complex processes demanding these cations, such as Mn2+-dependent glycosylation or systemic Ca2+ signaling, are covered in some detail if they have not been reviewed recently or if recent findings add to current models. The function of Ca2+ as signaling agent released from organelles into the cytosol and within the organelles themselves is a recurrent theme of this review, again keeping the interference by Mn2+ in mind. The involvement of organellar channels [e.g. glutamate receptor-likes (GLR), cyclic nucleotide-gated channels (CNGC), mitochondrial conductivity units (MCU), and two-pore channel1 (TPC1)], transporters (e.g. natural resistance-associated macrophage proteins (NRAMP), Ca2+ exchangers (CAX), metal tolerance proteins (MTP), and bivalent cation transporters (BICAT)], and pumps [autoinhibited Ca2+-ATPases (ACA) and ER Ca2+-ATPases (ECA)] in the import and export of organellar Ca2+ and Mn2+ is scrutinized, whereby current controversial issues are pointed out. Mechanisms in animals and yeast are taken into account where they may provide a blueprint for processes in plants, in particular, with respect to tunable molecular mechanisms of Ca2+ versus Mn2+ selectivity.
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Affiliation(s)
- Jie He
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Nico Rössner
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Minh T T Hoang
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Santiago Alejandro
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Edgar Peiter
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
- Author for communication:
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Initiation of cytosolic plant purine nucleotide catabolism involves a monospecific xanthosine monophosphate phosphatase. Nat Commun 2021; 12:6846. [PMID: 34824243 PMCID: PMC8616923 DOI: 10.1038/s41467-021-27152-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 11/02/2021] [Indexed: 12/05/2022] Open
Abstract
In plants, guanosine monophosphate (GMP) is synthesized from adenosine monophosphate via inosine monophosphate and xanthosine monophosphate (XMP) in the cytosol. It has been shown recently that the catabolic route for adenylate-derived nucleotides bifurcates at XMP from this biosynthetic route. Dephosphorylation of XMP and GMP by as yet unknown phosphatases can initiate cytosolic purine nucleotide catabolism. Here we show that Arabidopsis thaliana possesses a highly XMP-specific phosphatase (XMPP) which is conserved in vascular plants. We demonstrate that XMPP catalyzes the irreversible entry reaction of adenylate-derived nucleotides into purine nucleotide catabolism in vivo, whereas the guanylates enter catabolism via an unidentified GMP phosphatase and guanosine deaminase which are important to maintain purine nucleotide homeostasis. We also present a crystal structure and mutational analysis of XMPP providing a rationale for its exceptionally high substrate specificity, which is likely required for the efficient catalysis of the very small XMP pool in vivo. Dephosphorylation of xanthosine monophosphate (XMP) initiates purine nucleotide catabolism in plant cells. Here the authors identify an XMP phosphatase from Arabidopsis that channels XMP towards catabolism in vivo and demonstrate the structural basis for its XMP specificity.
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12
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Seo JS, Kim JK. Nitrogen molecular sensors and their use for screening mutants involved in nitrogen use efficiency. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110587. [PMID: 32771146 DOI: 10.1016/j.plantsci.2020.110587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/22/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
Nitrogen (N) is an essential macronutrient that is required for plant growth and development and has a major impact on crop yield and biomass. However, excessive application of N-based fertilizer results in environmental pollution and increases cultivation cost. A significant target of crop biotechnology is to develop crop varieties with improved N use efficiency (NUE), thereby overcoming these issues. While various aspects of plant N uptake and utilization have been studied, many factors that fundamentally affect NUE remain uncharacterized. For example, much remains to be learnt about the genes that determine NUE. One of the significant barriers to studying NUE is the absence of an in vivo N monitoring system. There are currently several methods for measuring plant N status, but they have limitations in terms of screening for NUE mutants and sensitive NUE assessment. Here, we describe strategies for generating and screening mutant pools using N molecular sensors, comprised of the rice genes OsALN and OsUPS1, the expression of which is sensitive to endogenous N status. Forward and reverse genetic approaches using the molecular N sensors will help identify molecular mechanisms underlying NUE.
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Affiliation(s)
- Jun Sung Seo
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Ju-Kon Kim
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea.
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13
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Thu SW, Lu MZ, Carter AM, Collier R, Gandin A, Sitton CC, Tegeder M. Role of ureides in source-to-sink transport of photoassimilates in non-fixing soybean. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4495-4511. [PMID: 32188989 PMCID: PMC7475099 DOI: 10.1093/jxb/eraa146] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/16/2020] [Indexed: 05/03/2023]
Abstract
Nitrogen (N)-fixing soybean plants use the ureides allantoin and allantoic acid as major long-distance transport forms of N, but in non-fixing, non-nodulated plants amino acids mainly serve in source-to-sink N allocation. However, some ureides are still synthesized in roots of non-fixing soybean, and our study addresses the role of ureide transport processes in those plants. In previous work, legume ureide permeases (UPSs) were identified that are involved in cellular import of allantoin and allantoic acid. Here, UPS1 from common bean was expressed in the soybean phloem, which resulted in enhanced source-to-sink transport of ureides in the transgenic plants. This was accompanied by increased ureide synthesis and elevated allantoin and allantoic acid root-to-sink transport. Interestingly, amino acid assimilation, xylem transport, and phloem partitioning to sinks were also strongly up-regulated. In addition, photosynthesis and sucrose phloem transport were improved in the transgenic plants. These combined changes in source physiology and assimilate partitioning resulted in increased vegetative growth and improved seed numbers. Overall, the results support that ureide transport processes in non-fixing plants affect source N and carbon acquisition and assimilation as well as source-to-sink translocation of N and carbon assimilates with consequences for plant growth and seed development.
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Affiliation(s)
- Sandi Win Thu
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Ming-Zhu Lu
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Amanda M Carter
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Ray Collier
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Anthony Gandin
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Ciera Chenoa Sitton
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Mechthild Tegeder
- School of Biological Sciences, Washington State University, Pullman, WA, USA
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14
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Alejandro S, Höller S, Meier B, Peiter E. Manganese in Plants: From Acquisition to Subcellular Allocation. FRONTIERS IN PLANT SCIENCE 2020; 11:300. [PMID: 32273877 PMCID: PMC7113377 DOI: 10.3389/fpls.2020.00300] [Citation(s) in RCA: 198] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/02/2020] [Indexed: 05/02/2023]
Abstract
Manganese (Mn) is an important micronutrient for plant growth and development and sustains metabolic roles within different plant cell compartments. The metal is an essential cofactor for the oxygen-evolving complex (OEC) of the photosynthetic machinery, catalyzing the water-splitting reaction in photosystem II (PSII). Despite the importance of Mn for photosynthesis and other processes, the physiological relevance of Mn uptake and compartmentation in plants has been underrated. The subcellular Mn homeostasis to maintain compartmented Mn-dependent metabolic processes like glycosylation, ROS scavenging, and photosynthesis is mediated by a multitude of transport proteins from diverse gene families. However, Mn homeostasis may be disturbed under suboptimal or excessive Mn availability. Mn deficiency is a serious, widespread plant nutritional disorder in dry, well-aerated and calcareous soils, as well as in soils containing high amounts of organic matter, where bio-availability of Mn can decrease far below the level that is required for normal plant growth. By contrast, Mn toxicity occurs on poorly drained and acidic soils in which high amounts of Mn are rendered available. Consequently, plants have evolved mechanisms to tightly regulate Mn uptake, trafficking, and storage. This review provides a comprehensive overview, with a focus on recent advances, on the multiple functions of transporters involved in Mn homeostasis, as well as their regulatory mechanisms in the plant's response to different conditions of Mn availability.
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Affiliation(s)
- Santiago Alejandro
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Salle), Germany
| | | | | | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Salle), Germany
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15
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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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16
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Witte CP, Herde M. Nucleotide Metabolism in Plants. PLANT PHYSIOLOGY 2020; 182:63-78. [PMID: 31641078 PMCID: PMC6945853 DOI: 10.1104/pp.19.00955] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/15/2019] [Indexed: 05/14/2023]
Abstract
Nucleotide metabolism is an essential function in plants.
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Affiliation(s)
- Claus-Peter Witte
- Leibniz Universität Hannover, Department of Molecular Nutrition and Biochemistry of Plants, Herrenhäuser Strasse 2, 30419 Hannover, Germany
| | - Marco Herde
- Leibniz Universität Hannover, Department of Molecular Nutrition and Biochemistry of Plants, Herrenhäuser Strasse 2, 30419 Hannover, Germany
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17
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Quiles FA, Galvez-Valdivieso G, Guerrero-Casado J, Pineda M, Piedras P. Relationship between ureidic/amidic metabolism and antioxidant enzymatic activities in legume seedlings. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 138:1-8. [PMID: 30825724 DOI: 10.1016/j.plaphy.2019.02.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/18/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
Ureides are nitrogenous compounds with a special function in some legume under nitrogen fixing conditions, the ureidic legumes. In this group, ureides are the predominant nitrogen transport molecule from nodules to the upper part, whereas amidic legumes use amides as nitrogen transport compounds. In this study, the ureide levels have been analysed in seedlings from four ureidic and four amidic legume plants. It has been found that the differentiation among ureide and amide plants already exists in seedlings during early seedling development, with high levels of ureide and allantoinase activity in cotyledons and embryonic axes from ureide plants. Since ureides have been implicated in the response of plant to several stress, total hydrosoluble antioxidant capacity and the levels of several antioxidant activities have been determined and compared among these two legume groups. The total antioxidant capacity did not follow any differential pattern in cotyledons or embryonic axes for the analysed plants. The levels of superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase in both embryonic axes and cotyledons are statistical different between amide and ureide seedlings, whereas the catalase activity was similar among these groups of plants. We discuss than amides and ureides could follow different strategies to protect against oxidation.
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Affiliation(s)
- Francisco A Quiles
- Departamento de Botánica, Ecología y Fisiología Vegetal. Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif, Severo Ochoa, Universidad de Córdoba, Córdoba, Spain
| | - Gregorio Galvez-Valdivieso
- Departamento de Botánica, Ecología y Fisiología Vegetal. Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif, Severo Ochoa, Universidad de Córdoba, Córdoba, Spain
| | - Jose Guerrero-Casado
- Facultad de Ciencias Veterinarias. Universidad Técnica de Manabí, Portoviejo, Manabí, Ecuador
| | - Manuel Pineda
- Departamento de Botánica, Ecología y Fisiología Vegetal. Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif, Severo Ochoa, Universidad de Córdoba, Córdoba, Spain
| | - Pedro Piedras
- Departamento de Botánica, Ecología y Fisiología Vegetal. Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus Rabanales, Edif, Severo Ochoa, Universidad de Córdoba, Córdoba, Spain.
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18
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Baccolini C, Witte CP. AMP and GMP Catabolism in Arabidopsis Converge on Xanthosine, Which Is Degraded by a Nucleoside Hydrolase Heterocomplex. THE PLANT CELL 2019; 31:734-751. [PMID: 30787180 PMCID: PMC6482636 DOI: 10.1105/tpc.18.00899] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/28/2019] [Accepted: 02/14/2019] [Indexed: 05/17/2023]
Abstract
Plants can fully catabolize purine nucleotides. A firmly established central intermediate is the purine base xanthine. In the current widely accepted model of plant purine nucleotide catabolism, xanthine can be generated in various ways involving either inosine and hypoxanthine or guanosine and xanthosine as intermediates. In a comprehensive mutant analysis involving single and multiple mutants of urate oxidase, xanthine dehydrogenase, nucleoside hydrolases, guanosine deaminase, and hypoxanthine guanine phosphoribosyltransferase, we demonstrate that purine nucleotide catabolism in Arabidopsis (Arabidopsis thaliana) mainly generates xanthosine, but not inosine and hypoxanthine, and that xanthosine is derived from guanosine deamination and a second source, likely xanthosine monophosphate dephosphorylation. Nucleoside hydrolase 1 (NSH1) is known to be essential for xanthosine hydrolysis, but the in vivo function of a second cytosolic nucleoside hydrolase, NSH2, is unclear. We demonstrate that NSH1 activates NSH2 in vitro and in vivo, forming a complex with almost two orders of magnitude higher catalytic efficiency for xanthosine hydrolysis than observed for NSH1 alone. Remarkably, an inactive NSH1 point mutant can activate NSH2 in vivo, fully preventing purine nucleoside accumulation in nsh1 background. Our data lead to an altered model of purine nucleotide catabolism that includes an NSH heterocomplex as a central component.
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Affiliation(s)
- Chiara Baccolini
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany
| | - Claus-Peter Witte
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany
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19
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Casartelli A, Melino VJ, Baumann U, Riboni M, Suchecki R, Jayasinghe NS, Mendis H, Watanabe M, Erban A, Zuther E, Hoefgen R, Roessner U, Okamoto M, Heuer S. Opposite fates of the purine metabolite allantoin under water and nitrogen limitations in bread wheat. PLANT MOLECULAR BIOLOGY 2019; 99:477-497. [PMID: 30721380 DOI: 10.1007/s11103-019-00831-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 01/24/2019] [Indexed: 05/06/2023]
Abstract
Degradation of nitrogen-rich purines is tightly and oppositely regulated under drought and low nitrogen supply in bread wheat. Allantoin is a key target metabolite for improving nitrogen homeostasis under stress. The metabolite allantoin is an intermediate of the catabolism of purines (components of nucleotides) and is known for its housekeeping role in nitrogen (N) recycling and also for its function in N transport and storage in nodulated legumes. Allantoin was also shown to differentially accumulate upon abiotic stress in a range of plant species but little is known about its role in cereals. To address this, purine catabolic pathway genes were identified in hexaploid bread wheat and their chromosomal location was experimentally validated. A comparative study of two Australian bread wheat genotypes revealed a highly significant increase of allantoin (up to 29-fold) under drought. In contrast, allantoin significantly decreased (up to 22-fold) in response to N deficiency. The observed changes were accompanied by transcriptional adjustment of key purine catabolic genes, suggesting that the recycling of purine-derived N is tightly regulated under stress. We propose opposite fates of allantoin in plants under stress: the accumulation of allantoin under drought circumvents its degradation to ammonium (NH4+) thereby preventing N losses. On the other hand, under N deficiency, increasing the NH4+ liberated via allantoin catabolism contributes towards the maintenance of N homeostasis.
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Affiliation(s)
- Alberto Casartelli
- School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia
- Strube Research GmbH & Co. KG, 38387, Söllingen, Germany
| | - Vanessa J Melino
- School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia
- School of Agriculture and Food, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ute Baumann
- School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia
| | - Matteo Riboni
- School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia
| | - Radoslaw Suchecki
- School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia
| | - Nirupama S Jayasinghe
- Metabolomics Australia, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Himasha Mendis
- Metabolomics Australia, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Mutsumi Watanabe
- Max Plank Institute of Molecular Plant Physiology, 14476, Potsdam, Golm, Germany
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan
| | - Alexander Erban
- Max Plank Institute of Molecular Plant Physiology, 14476, Potsdam, Golm, Germany
| | - Ellen Zuther
- Max Plank Institute of Molecular Plant Physiology, 14476, Potsdam, Golm, Germany
| | - Rainer Hoefgen
- Max Plank Institute of Molecular Plant Physiology, 14476, Potsdam, Golm, Germany
| | - Ute Roessner
- Metabolomics Australia, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Mamoru Okamoto
- School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia
| | - Sigrid Heuer
- School of Agriculture Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia.
- Rothamsted Research, Plant Science Department, Harpenden, Hertfordshire, AL5 2JQ, UK.
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20
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Zhou K. Glycosylphosphatidylinositol-Anchored Proteins in Arabidopsis and One of Their Common Roles in Signaling Transduction. FRONTIERS IN PLANT SCIENCE 2019; 10:1022. [PMID: 31555307 PMCID: PMC6726743 DOI: 10.3389/fpls.2019.01022] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/22/2019] [Indexed: 05/17/2023]
Abstract
Diverse proteins are found modified with glycosylphosphatidylinositol (GPI) at their carboxyl terminus in eukaryotes, which allows them to associate with membrane lipid bilayers and anchor on the external surface of the plasma membrane. GPI-anchored proteins (GPI-APs) play crucial roles in various processes, and more and more GPI-APs have been identified and studied. In this review, previous genomic and proteomic predictions of GPI-APs in Arabidopsis have been updated, which reveal their high abundance and complexity. From studies of individual GPI-APs in Arabidopsis, certain GPI-APs have been found associated with partner receptor-like kinases (RLKs), targeting RLKs to their subcellular localization and helping to recognize extracellular signaling polypeptide ligands. Interestingly, the association might also be involved in ligand selection. The analyses suggest that GPI-APs are essential and widely involved in signal transduction through association with RLKs.
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21
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Takagi H, Watanabe S, Tanaka S, Matsuura T, Mori IC, Hirayama T, Shimada H, Sakamoto A. Disruption of ureide degradation affects plant growth and development during and after transition from vegetative to reproductive stages. BMC PLANT BIOLOGY 2018; 18:287. [PMID: 30458716 PMCID: PMC6245725 DOI: 10.1186/s12870-018-1491-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/19/2018] [Indexed: 05/08/2023]
Abstract
BACKGROUND The ureides allantoin and allantoate are major metabolic intermediates of purine catabolism with high nitrogen-to-carbon ratios. Ureides play a key role in nitrogen utilization in ureide-type legumes, but their effects on growth and development in non-legume plants are poorly understood. Here, we examined the effects of knocking out genes encoding ureide-degrading enzymes, allantoinase (ALN) and allantoate amidohydrolase (AAH), on the vegetative-to-reproductive transition and subsequent growth of Arabidopsis plants. RESULTS The ureide-degradation mutants (aln and aah) showed symptoms similar to those of nitrogen deficiency: early flowering, reduced size at maturity, and decreased fertility. Consistent with these phenotypes, carbon-to-nitrogen ratios and nitrogen-use efficiencies were significantly decreased in ureide-degradation mutants; however, adding nitrogen to irrigation water did not alleviate the reduced growth of these mutants. In addition to nitrogen status, levels of indole-3-acetic acid and gibberellin in five-week-old plants were also affected by the aln mutations. To test the possibility that ureides are remobilized from source to sink organs, we measured ureide levels in various organs. In wild-type plants, allantoate accumulated predominantly in inflorescence stems and siliques; this accumulation was augmented by disruption of its catabolism. Mutants lacking ureide transporters, ureide permeases 1 and 2 (UPS1 and UPS2), exhibited phenotypes similar to those of the ureide-degradation mutants, but had decreased allantoate levels in the reproductive organs. Transcript analysis in wild-type plants suggested that genes involved in allantoate synthesis and ureide transport were coordinately upregulated in senescing leaves. CONCLUSIONS This study demonstrates that ureide degradation plays an important role in supporting healthy growth and development in non-legume Arabidopsis during and after transition from vegetative to reproductive stages.
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Affiliation(s)
- Hiroshi Takagi
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan
- Present Address: Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN 55108 USA
| | - Shunsuke Watanabe
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan
- Present Address: Center for Sustainable Resource Science, RIKEN, Yokohama, 230-0045 Japan
| | - Shoma Tanaka
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan
| | - Takakazu Matsuura
- Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046 Japan
| | - Izumi C. Mori
- Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046 Japan
| | - Takashi Hirayama
- Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046 Japan
| | - Hiroshi Shimada
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan
| | - Atsushi Sakamoto
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan
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22
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Soltabayeva A, Srivastava S, Kurmanbayeva A, Bekturova A, Fluhr R, Sagi M. Early Senescence in Older Leaves of Low Nitrate-Grown Atxdh1 Uncovers a Role for Purine Catabolism in N Supply. PLANT PHYSIOLOGY 2018; 178:1027-1044. [PMID: 30190419 PMCID: PMC6236613 DOI: 10.1104/pp.18.00795] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/25/2018] [Indexed: 05/19/2023]
Abstract
The nitrogen (N)-rich ureides allantoin and allantoate, which are products of purine catabolism, play a role in N delivery in Leguminosae. Here, we examined their role as an N source in nonlegume plants using Arabidopsis (Arabidopsis thaliana) plants mutated in XANTHINE DEHYDROGENASE1 (AtXDH1), a catalytic bottleneck in purine catabolism. Older leaves of the Atxdh1 mutant exhibited early senescence, lower soluble protein, and lower organic N levels as compared with wild-type older leaves when grown with 1 mm nitrate but were comparable to the wild type under 5 mm nitrate. Similar nitrate-dependent senescence phenotypes were evident in the older leaves of allantoinase (Ataln) and allantoate amidohydrolase (Ataah) mutants, which also are impaired in purine catabolism. Under low-nitrate conditions, xanthine accumulated in older leaves of Atxdh1, whereas allantoin accumulated in both older and younger leaves of Ataln but not in wild-type leaves, indicating the remobilization of xanthine-degraded products from older to younger leaves. Supporting this notion, ureide transporter expression was enhanced in older leaves of the wild type in low-nitrate as compared with high-nitrate conditions. Elevated transcripts and proteins of AtXDH and AtAAH were detected in low-nitrate-grown wild-type plants, indicating regulation at protein and transcript levels. The higher nitrate reductase activity in Atxdh1 leaves compared with wild-type leaves indicated a need for nitrate assimilation products. Together, these results indicate that the absence of remobilized purine-degraded N from older leaves of Atxdh1 caused senescence symptoms, a result of higher chloroplastic protein degradation in older leaves of low-nitrate-grown plants.
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Affiliation(s)
- Aigerim Soltabayeva
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Sudhakar Srivastava
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Assylay Kurmanbayeva
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Aizat Bekturova
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Robert Fluhr
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Moshe Sagi
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
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A fundamental catalytic difference between zinc and manganese dependent enzymes revealed in a bacterial isatin hydrolase. Sci Rep 2018; 8:13104. [PMID: 30166577 PMCID: PMC6117287 DOI: 10.1038/s41598-018-31259-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/15/2018] [Indexed: 11/18/2022] Open
Abstract
The catalytic mechanism of the cyclic amidohydrolase isatin hydrolase depends on a catalytically active manganese in the substrate-binding pocket. The Mn2+ ion is bound by a motif also present in other metal dependent hydrolases like the bacterial kynurenine formamidase. The crystal structures of the isatin hydrolases from Labrenzia aggregata and Ralstonia solanacearum combined with activity assays allow for the identification of key determinants specific for the reaction mechanism. Active site residues central to the hydrolytic mechanism include a novel catalytic triad Asp-His-His supported by structural comparison and hybrid quantum mechanics/classical mechanics simulations. A hydrolytic mechanism for a Mn2+ dependent amidohydrolases that disfavour Zn2+ as the primary catalytically active site metal proposed here is supported by these likely cases of convergent evolution. The work illustrates a fundamental difference in the substrate-binding mode between Mn2+ dependent isatin hydrolase like enzymes in comparison with the vast number of Zn2+ dependent enzymes.
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Chen M, Urs MJ, Sánchez-González I, Olayioye MA, Herde M, Witte CP. m 6A RNA Degradation Products Are Catabolized by an Evolutionarily Conserved N 6-Methyl-AMP Deaminase in Plant and Mammalian Cells. THE PLANT CELL 2018; 30:1511-1522. [PMID: 29884623 PMCID: PMC6096584 DOI: 10.1105/tpc.18.00236] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/25/2018] [Accepted: 06/08/2018] [Indexed: 05/17/2023]
Abstract
N6-methylated adenine (m6A) is the most frequent posttranscriptional modification in eukaryotic mRNA. Turnover of RNA generates N6-methylated AMP (N6-mAMP), which has an unclear metabolic fate. We show that Arabidopsis thaliana and human cells require an N6-mAMP deaminase (ADAL, renamed MAPDA) to catabolize N6-mAMP to inosine monophosphate in vivo by hydrolytically removing the aminomethyl group. A phylogenetic, structural, and biochemical analysis revealed that many fungi partially or fully lack MAPDA, which coincides with a minor role of N6A-RNA methylation in these organisms. MAPDA likely protects RNA from m6A misincorporation. This is required because eukaryotic RNA polymerase can use N6-mATP as a substrate. Upon abrogation of MAPDA, root growth is slightly reduced, and the N6-methyladenosine, N6-mAMP, and N6-mATP concentrations are increased in Arabidopsis. Although this will potentially lead to m6A misincorporation into RNA, we show that the frequency is too low to be reliably detected in vivo. Since N6-mAMP was severalfold more abundant than N6-mATP in MAPDA mutants, we speculate that additional molecular filters suppress the generation of N6-mATP. Enzyme kinetic data indicate that adenylate kinases represent such filters being highly selective for AMP versus N6-mAMP phosphorylation. We conclude that a multilayer molecular protection system is in place preventing N6-mAMP accumulation and salvage.
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Affiliation(s)
- Mingjia Chen
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, 30419 Hannover, Germany
| | - Mounashree J Urs
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, 30419 Hannover, Germany
| | | | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
| | - Marco Herde
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, 30419 Hannover, Germany
| | - Claus-Peter Witte
- Department of Molecular Nutrition and Biochemistry of Plants, Institute of Plant Nutrition, Leibniz University Hannover, 30419 Hannover, Germany
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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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Yazdanpanah F, Hanson J, Hilhorst HW, Bentsink L. Differentially expressed genes during the imbibition of dormant and after-ripened seeds - a reverse genetics approach. BMC PLANT BIOLOGY 2017; 17:151. [PMID: 28893189 PMCID: PMC5594490 DOI: 10.1186/s12870-017-1098-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 09/05/2017] [Indexed: 05/12/2023]
Abstract
BACKGROUND Seed dormancy, defined as the incapability of a viable seed to germinate under favourable conditions, is an important trait in nature and agriculture. Despite extensive research on dormancy and germination, many questions about the molecular mechanisms controlling these traits remain unanswered, likely due to its genetic complexity and the large environmental effects which are characteristic of these quantitative traits. To boost research towards revealing mechanisms in the control of seed dormancy and germination we depend on the identification of genes controlling those traits. METHODS We used transcriptome analysis combined with a reverse genetics approach to identify genes that are prominent for dormancy maintenance and germination in imbibed seeds of Arabidopsis thaliana. Comparative transcriptomics analysis was employed on freshly harvested (dormant) and after-ripened (AR; non-dormant) 24-h imbibed seeds of four different DELAY OF GERMINATION near isogenic lines (DOGNILs) and the Landsberg erecta (Ler) wild type with varying levels of primary dormancy. T-DNA knock-out lines of the identified genes were phenotypically investigated for their effect on dormancy and AR. RESULTS We identified conserved sets of 46 and 25 genes which displayed higher expression in seeds of all dormant and all after-ripened DOGNILs and Ler, respectively. Knock-out mutants in these genes showed dormancy and germination related phenotypes. CONCLUSIONS Most of the identified genes had not been implicated in seed dormancy or germination. This research will be useful to further decipher the molecular mechanisms by which these important ecological and commercial traits are regulated.
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Affiliation(s)
- Farzaneh Yazdanpanah
- Wageningen Seed Laboratory, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Johannes Hanson
- Umeå Plant Science Center, Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden
- Department of Molecular Plant Physiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Henk W.M. Hilhorst
- Wageningen Seed Laboratory, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Leónie Bentsink
- Wageningen Seed Laboratory, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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Myrach T, Zhu A, Witte CP. The assembly of the plant urease activation complex and the essential role of the urease accessory protein G (UreG) in delivery of nickel to urease. J Biol Chem 2017; 292:14556-14565. [PMID: 28710280 PMCID: PMC5582847 DOI: 10.1074/jbc.m117.780403] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 07/11/2017] [Indexed: 12/24/2022] Open
Abstract
Urease is a ubiquitous nickel metalloenzyme. In plants, its activation requires three urease accessory proteins (UAPs), UreD, UreF, and UreG. In bacteria, the UAPs interact with urease and facilitate activation, which involves the channeling of two nickel ions into the active site. So far this process has not been investigated in eukaryotes. Using affinity pulldowns of Strep-tagged UAPs from Arabidopsis and rice transiently expressed in planta, we demonstrate that a urease-UreD-UreF-UreG complex exists in plants and show its stepwise assembly. UreG is crucial for nickel delivery because UreG-dependent urease activation in vitro was observed only with UreG obtained from nickel-sufficient plants. This activation competence could not be generated in vitro by incubation of UreG with nickel, bicarbonate, and GTP. Compared with their bacterial orthologs, plant UreGs possess an N-terminal extension containing a His- and Asp/Glu-rich hypervariable region followed by a highly conserved sequence comprising two potential HXH metal-binding sites. Complementing the ureG-1 mutant of Arabidopsis with N-terminal deletion variants of UreG demonstrated that the hypervariable region has a minor impact on activation efficiency, whereas the conserved region up to the first HXH motif is highly beneficial and up to the second HXH motif strictly required for activation. We also show that urease reaches its full activity several days after nickel becomes available in the leaves, indicating that urease activation is limited by nickel accessibility in vivo Our data uncover the crucial role of UreG for nickel delivery during eukaryotic urease activation, inciting further investigations of the details of this process.
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Affiliation(s)
- Till Myrach
- From the Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, Königin-Luise-Strasse 12-16, 14195 Berlin, Germany and
| | - Anting Zhu
- Leibniz Universität Hannover, Institute of Plant Nutrition, Molecular Nutrition and Biochemistry of Plants, Herrenhäuser Strasse 2, 30419 Hannover, Germany
| | - Claus-Peter Witte
- Leibniz Universität Hannover, Institute of Plant Nutrition, Molecular Nutrition and Biochemistry of Plants, Herrenhäuser Strasse 2, 30419 Hannover, Germany
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Uric acid in plants and microorganisms: Biological applications and genetics - A review. J Adv Res 2017; 8:475-486. [PMID: 28748114 PMCID: PMC5512154 DOI: 10.1016/j.jare.2017.05.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/07/2017] [Accepted: 05/08/2017] [Indexed: 11/23/2022] Open
Abstract
Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing) of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.
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Smolko A, Šupljika F, Martinčić J, Jajčanin-Jozić N, Grabar-Branilović M, Tomić S, Ludwig-Müller J, Piantanida I, Salopek-Sondi B. The role of conserved Cys residues in Brassica rapa auxin amidohydrolase: Cys139 is crucial for the enzyme activity and Cys320 regulates enzyme stability. Phys Chem Chem Phys 2017; 18:8890-900. [PMID: 26959939 DOI: 10.1039/c5cp06301a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Brassica rapa auxin amidohydrolase (BrILL2) participates in the homeostasis of the plant hormones auxins by hydrolyzing the amino acid conjugates of auxins, thereby releasing the free active form of hormones. Herein, the potential role of the two conserved Cys residues of BrILL2 (at sequence positions 139 and 320) has been investigated by using interdisciplinary approaches and methods of molecular biology, biochemistry, biophysics and molecular modelling. The obtained results show that both Cys residues participate in the regulation of enzyme activity. Cys320 located in the satellite domain of the enzyme is mainly responsible for protein stability and regulation of enzyme activity through polymer formation, as has been revealed by enzyme kinetics and differential scanning calorimetry analysis of the BrILL2 wild type and mutants C320S and C139S. Cys139 positioned in the active site of the catalytic domain is involved in the coordination of one Mn(2+) ion of the bimetal center and is crucial for the enzymatic activity. Although the point mutation Cys139 to Ser causes the loss of enzyme activity, it does not affect the metal binding to the BrILL2 enzyme, as has been shown by isothermal titration calorimetry, circular dichroism spectropolarimetry and differential scanning calorimetry data. MD simulations (200 ns) revealed a different active site architecture of the BrILL2C139S mutant in comparison to the wild type enzyme. Additional possible reasons for the inactivity of the BrILL2C139S mutant have been discussed based on MD simulations and MM-PBSA free energy calculations of BrILL2 enzyme complexes (wt and C139S mutant) with IPA-Ala as a substrate.
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Affiliation(s)
- Ana Smolko
- Division of Molecular Biology, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
| | - Filip Šupljika
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
| | - Jelena Martinčić
- Division of Molecular Biology, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
| | - Nina Jajčanin-Jozić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
| | | | - Sanja Tomić
- Division of Physical Chemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | | | - Ivo Piantanida
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
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Irani S, Todd CD. Ureide metabolism under abiotic stress in Arabidopsis thaliana. JOURNAL OF PLANT PHYSIOLOGY 2016; 199:87-95. [PMID: 27302009 DOI: 10.1016/j.jplph.2016.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/17/2016] [Accepted: 05/18/2016] [Indexed: 05/21/2023]
Abstract
Ureides are nitrogenous compounds derived from purine catabolism which contribute to nitrogen recycling in plants. Accumulation of ureide compounds has been reported in a number of plant species under stress conditions, suggesting their involvement in plants' response to stress. In this research a biochemical and molecular approach was applied to address the ureide accumulation under abiotic stress conditions in Arabidopsis thaliana. Ureide concentration and changes in expression of ureide metabolic genes were examined in response to drought, NaCl and mannitol treatments. Additionally, an Arabidopsis allantoinase (ALN) mutant with constitutive accumulation of a ureide compound, allantoin, was used to investigate the impact of high levels of this compound on drought and NaCl stress responses. In the leaf tissue of adult plants allantoin accumulated in response to soil drying. Transcription of urate oxidase (UO), involved in allantoin production, was highly up-regulated under the same conditions. Allantoin and allantoate also accumulated in seedlings following treatment with NaCl or mannitol. aln mutants with enhanced levels of allantoin exhibited higher tolerance to drought and NaCl. Hydrogen peroxide and superoxide did not accumulate in the aln mutant leaves to the same degree in response to drought when compared to the wild-type. Our results suggest that ureide metabolism and accumulation contribute to the abiotic stress response which is regulated, at least in part, at the transcriptional level. Higher concentrations of allantoin in the mutant elevates abiotic stress tolerance, possibly by reducing oxidative damage.
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Affiliation(s)
- Solmaz Irani
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
| | - Christopher D Todd
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada.
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Chen M, Herde M, Witte CP. Of the Nine Cytidine Deaminase-Like Genes in Arabidopsis, Eight Are Pseudogenes and Only One Is Required to Maintain Pyrimidine Homeostasis in Vivo. PLANT PHYSIOLOGY 2016; 171:799-809. [PMID: 27208239 PMCID: PMC4902590 DOI: 10.1104/pp.15.02031] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/31/2016] [Indexed: 05/17/2023]
Abstract
CYTIDINE DEAMINASE (CDA) catalyzes the deamination of cytidine to uridine and ammonia in the catabolic route of C nucleotides. The Arabidopsis (Arabidopsis thaliana) CDA gene family comprises nine members, one of which (AtCDA) was shown previously in vitro to encode an active CDA. A possible role in C-to-U RNA editing or in antiviral defense has been discussed for other members. A comprehensive bioinformatic analysis of plant CDA sequences, combined with biochemical functionality tests, strongly suggests that all Arabidopsis CDA family members except AtCDA are pseudogenes and that most plants only require a single CDA gene. Soybean (Glycine max) possesses three CDA genes, but only two encode functional enzymes and just one has very high catalytic efficiency. AtCDA and soybean CDAs are located in the cytosol. The functionality of AtCDA in vivo was demonstrated with loss-of-function mutants accumulating high amounts of cytidine but also CMP, cytosine, and some uridine in seeds. Cytidine hydrolysis in cda mutants is likely caused by NUCLEOSIDE HYDROLASE1 (NSH1) because cytosine accumulation is strongly reduced in a cda nsh1 double mutant. Altered responses of the cda mutants to fluorocytidine and fluorouridine indicate that a dual specific nucleoside kinase is involved in cytidine as well as uridine salvage. CDA mutants display a reduction in rosette size and have fewer leaves compared with the wild type, which is probably not caused by defective pyrimidine catabolism but by the accumulation of pyrimidine catabolism intermediates reaching toxic concentrations.
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Affiliation(s)
- Mingjia Chen
- Leibniz University Hannover, Institute of Plant Nutrition, Department of Molecular Nutrition and Biochemistry of Plants, 30419 Hannover, Germany
| | - Marco Herde
- Leibniz University Hannover, Institute of Plant Nutrition, Department of Molecular Nutrition and Biochemistry of Plants, 30419 Hannover, Germany
| | - Claus-Peter Witte
- Leibniz University Hannover, Institute of Plant Nutrition, Department of Molecular Nutrition and Biochemistry of Plants, 30419 Hannover, Germany
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Cetz-Chel JE, Balcázar-López E, Esquivel-Naranjo EU, Herrera-Estrella A. The Trichoderma atroviride putative transcription factor Blu7 controls light responsiveness and tolerance. BMC Genomics 2016; 17:327. [PMID: 27142227 PMCID: PMC4855978 DOI: 10.1186/s12864-016-2639-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 04/22/2016] [Indexed: 11/23/2022] Open
Abstract
Background Most living organisms use sunlight as a source of energy and/or information about their environment. Consequently, they have developed mechanisms to sense light quality and quantity. In the fungus Trichoderma atroviride blue-light is perceived through the Blue Light Regulator Complex, which in turn up-regulates a set of genes (blu) and down-regulates another set (bld), triggering asexual reproduction. To gain insight into this process, we characterized the blu7 gene, which encodes a protein containing a C2H2 zinc finger domain. Results Δblu7 mutants show reduced conidiation at low light fluences, which is still clear even when exposed to saturating light. For the first time we show a genome wide survey of light regulated gene expression in T. atroviride, including RNA-seq analyses of the wild type and the Δblu7 strains after brief exposure to blue-light. Our data show a reduction in the number of induced genes and an increase in down-regulated genes in the mutant. Light activates stress responses and several metabolic processes in the wild type strain that are no longer activated in the mutant. In agreement with the misregulation of metabolic processes, continuous exposure to white light strongly inhibited growth of the ∆blu7 mutant, in a carbon source dependent fashion. RNA-seq analyses under constant white light using glucose as sole carbon source revealed that localization and transport process present the opposite regulation pattern in the ∆blu7 and wild type strains. Genes related to amino acid, sugar and general transporters were enriched in the induced genes in the mutant and the repressed genes of the wild type. Peptone supplemented in the media restored growth of the ∆blu7 mutant in constant light, suggesting a role of Blu7 in the regulation of nitrogen metabolism in the presence of light. Conclusions Blu7 appears to regulate light sensitivity in terms of induction of conidiation, and to play a major role in supporting growth under continuous exposure to light. The diminished conidiation observed in ∆blu7 mutants is likely due to misregulation of the cAMP signaling pathway and ROS production, whereas their low tolerance to continuous exposure to light indicates that Blu7 is required for adaptation. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2639-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- José E Cetz-Chel
- Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Sede Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36821, Irapuato, Guanajuato, Mexico
| | - Edgar Balcázar-López
- Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Sede Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36821, Irapuato, Guanajuato, Mexico
| | - Edgardo U Esquivel-Naranjo
- Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Sede Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36821, Irapuato, Guanajuato, Mexico.,Present Address: Unit for Basic and Applied Microbiology, Faculty of Natural Sciences, Autonomous University of Querétaro, Querétaro, 76230, Mexico
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Sede Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36821, Irapuato, Guanajuato, Mexico.
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Baral B, Teixeira da Silva JA, Izaguirre-Mayoral ML. Early signaling, synthesis, transport and metabolism of ureides. JOURNAL OF PLANT PHYSIOLOGY 2016; 193:97-109. [PMID: 26967003 DOI: 10.1016/j.jplph.2016.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/04/2015] [Accepted: 01/11/2016] [Indexed: 05/26/2023]
Abstract
The symbiosis between α nitrogen (N2)-fixing Proteobacteria (family Rhizobiaceae) and legumes belonging to the Fabaceae (a single phylogenetic group comprising three subfamilies: Caesalpinioideae, Mimosoideae and Papilionoideae) results in the formation of a novel root structure called a nodule, where atmospheric N2 is fixed into NH3(+). In the determinate type of nodules harbored by Rhizobium-nodulated Fabaceae species, newly synthesized NH3(+) is finally converted into allantoin (C4H6N4O3) and allantoic acid (C4H8N4O4) (ureides) through complex pathways involving at least 20 different enzymes that act synchronously in two types of nodule cells with contrasting ultrastructure, including the tree nodule cell organelles. Newly synthesized ureides are loaded into the network of nodule-root xylem vessels and transported to aerial organs by the transpirational water current. Once inside the leaves, ureides undergo an enzymatically driven reverse process to yield NH4(+) that is used for growth. This supports the role of ureides as key nitrogen (N)-compounds for the growth and yield of legumes nodulated by Rhizobium that grow in soils with a low N content. Thus, a concrete understanding of the mechanisms underlying ureide biogenesis and catabolism in legumes may help agrobiologists to achieve greater agricultural discoveries. In this review we focus on the transmembranal and transorganellar symplastic and apoplastic movement of N-precursors within the nodules, as well as on the occurrence, localization and properties of enzymes and genes involved in the biogenesis and catabolism of ureides. The synthesis and transport of ureides are not unique events in Rhizobium-nodulated N2-fixing legumes. Thus, a brief description of the synthesis and catabolism of ureides in non-legumes was included for comparison. The establishment of the symbiosis, nodule organogenesis and the plant's control of nodule number, synthesis and translocation of ureides via feed-back inhibition mechanisms are also reviewed.
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Affiliation(s)
- Bikash Baral
- Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 27, Latokartanonkaari 7, FIN-00014 Helsinki, Finland.
| | | | - Maria Luisa Izaguirre-Mayoral
- Biological Nitrogen Fixation Laboratory, Chemistry Department, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
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Kittur FS, Lalgondar M, Hung CY, Sane DC, Xie J. C-Terminally fused affinity Strep-tag II is removed by proteolysis from recombinant human erythropoietin expressed in transgenic tobacco plants. PLANT CELL REPORTS 2015; 34:507-16. [PMID: 25504272 PMCID: PMC4329255 DOI: 10.1007/s00299-014-1730-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 06/04/2023]
Abstract
KEY MESSAGE C -terminally fused Strep -tag II is removed from rhuEPO expressed in tobacco plants. The finding suggests that direct fusion of purification tags at the C -terminus of rhuEPO should be avoided. Asialo-erythropoietin (asialo-EPO), a desialylated form of EPO, is a potent tissue-protective agent. Recently, we and others have exploited a low-cost plant-based expression system to produce recombinant human asialo-EPO (asialo-rhuEPO(P)). To facilitate purification from plant extracts, Strep-tag II was engineered at the C-terminus of EPO. Although asialo-rhuEPO(P) was efficiently expressed in transgenic tobacco plants, affinity purification based on Strep -tag II did not result in the recovery of the protein. In this study, we investigated the stability of Strep-tag II tagged asialo-rhuEPO(P) expressed in tobacco plants to understand whether this fused tag is cleaved or inaccessible. Sequencing RT-PCR products confirmed that fused DNA sequences encoding Strep-tag II were properly transcribed, and three-dimensional protein structure model revealed that the tag must be fully accessible. However, Western blot analysis of leaf extracts and purified asialo-rhuEPO(P) revealed that the Strep-tag II was absent on the protein. Additionally, no peptide fragment containing Strep-tag II was identified in the LC-MS/MS analysis of purified protein further supporting that the affinity tag was absent on asialo-rhuEPO(P). However, Strep-tag II was detected on asialo-rhuEPO(P) that was retained in the endoplasmic reticulum, suggesting that the Strep-tag II is removed during protein secretion or extraction. These findings together with recent reports that C-terminally fused Strep-tag II or IgG Fc domain are also removed from EPO in tobacco plants, suggest that its C-terminus may be highly susceptible to proteolysis in tobacco plants. Therefore, direct fusion of purification tags at the C-terminus of EPO should be avoided while expressing it in tobacco plants.
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Affiliation(s)
- Farooqahmed S. Kittur
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Mallikarjun Lalgondar
- Center for Agribusiness Excellence, Tarleton State University, Stephenville, TX 76402, USA
| | - Chiu-Yueh Hung
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - David C. Sane
- Carilion Clinic and Virginia Tech Carilion School of Medicine, Roanoke VA 24014, USA
| | - Jiahua Xie
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA. 1801 Fayetteville Street, Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA; Phone:+1 919 530 6705; Fax: +1 919 530 6600
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Díaz-Leal JL, Torralbo F, Antonio Quiles F, Pineda M, Alamillo JM. Molecular and functional characterization of allantoate amidohydrolase from Phaseolus vulgaris. PHYSIOLOGIA PLANTARUM 2014; 152:43-58. [PMID: 24460648 DOI: 10.1111/ppl.12157] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 12/16/2013] [Accepted: 12/18/2013] [Indexed: 06/03/2023]
Abstract
Allantoate degradation is an essential step for recycling purine-ring nitrogen in all plants, but especially in tropical legumes where the ureides allantoate and allantoin are the main compounds used to store and transport the nitrogen fixed in nodules. Two enzymes, allantoate amidohydrolase (AAH) and allantoate amidinohydrolase (allantoicase), could catalyze allantoate breakdown, although only AAH-coding sequences have been found in plant genomes, whereas allantoicase-related sequences are restricted to animals and some microorganisms. A cDNA for AAH was cloned from Phaseolus vulgaris leaves. PvAAH is a single-copy gene encoding a polypeptide of 483 amino acids that conserves all putative AAH active-site domains. Expression and purification of the cDNA in Nicotiana benthamiana showed that the cloned sequence is a true AAH protein that yields ureidoglycine and ammonia, with a Km of 0.46 mM for allantoate. Optimized in vitro assay, quantitative RT-PCR and antibodies raised to the PvAAH protein were used to study AAH under physiological conditions. PvAAH is ubiquitously expressed in common bean tissues, although the highest transcript levels were found in leaves. In accordance with the mRNA expression levels, the highest PvAAH activity and allantoate concentration also occurred in the leaves. Comparison of transcript levels, protein amounts and enzymatic activity in plants grown with different nitrogen sources and upon drought stress conditions showed that PvAAH is regulated at posttranscriptional level. Moreover, RNAi silencing of AAH expression increases allantoate levels in the transgenic hairy roots, indicating that AAH should be the main enzyme involved in allantoate degradation in common bean.
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Affiliation(s)
- Juan Luis Díaz-Leal
- Departamento de Botánica, Ecología y Fisiología Vegetal, Campus de Excelencia Internacional Agroalimentario (CEIA3), Campus de Rabanales, Edif. Severo Ochoa, 1a Planta, Universidad de Córdoba, 14071x0, Córdoba, Spain
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Structural Insights into the Substrate Specificity of (S)-Ureidoglycolate Amidohydrolase and Its Comparison with Allantoate Amidohydrolase. J Mol Biol 2014; 426:3028-40. [DOI: 10.1016/j.jmb.2014.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 06/26/2014] [Accepted: 06/30/2014] [Indexed: 11/20/2022]
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Hauck OK, Scharnberg J, Escobar NM, Wanner G, Giavalisco P, Witte CP. Uric acid accumulation in an Arabidopsis urate oxidase mutant impairs seedling establishment by blocking peroxisome maintenance. THE PLANT CELL 2014; 26:3090-100. [PMID: 25052714 PMCID: PMC4145134 DOI: 10.1105/tpc.114.124008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/30/2014] [Accepted: 07/04/2014] [Indexed: 05/21/2023]
Abstract
Purine nucleotides can be fully catabolized by plants to recycle nutrients. We have isolated a urate oxidase (uox) mutant of Arabidopsis thaliana that accumulates uric acid in all tissues, especially in the developing embryo. The mutant displays a reduced germination rate and is unable to establish autotrophic growth due to severe inhibition of cotyledon development and nutrient mobilization from the lipid reserves in the cotyledons. The uox mutant phenotype is suppressed in a xanthine dehydrogenase (xdh) uox double mutant, demonstrating that the underlying cause is not the defective purine base catabolism, or the lack of UOX per se, but the elevated uric acid concentration in the embryo. Remarkably, xanthine accumulates to similar levels in the xdh mutant without toxicity. This is paralleled in humans, where hyperuricemia is associated with many diseases whereas xanthinuria is asymptomatic. Searching for the molecular cause of uric acid toxicity, we discovered a local defect of peroxisomes (glyoxysomes) mostly confined to the cotyledons of the mature embryos, which resulted in the accumulation of free fatty acids in dry seeds. The peroxisomal defect explains the developmental phenotypes of the uox mutant, drawing a novel link between uric acid and peroxisome function, which may be relevant beyond plants.
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Affiliation(s)
- Oliver K Hauck
- Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, 14195 Berlin, Germany
| | - Jana Scharnberg
- Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, 14195 Berlin, Germany
| | - Nieves Medina Escobar
- Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, 14195 Berlin, Germany
| | - Gerhard Wanner
- Biozentrum der Ludwig-Maximillians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Patrick Giavalisco
- Max-Planck-Institute for Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Claus-Peter Witte
- Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, 14195 Berlin, Germany
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Coleto I, Pineda M, Rodiño AP, De Ron AM, Alamillo JM. Comparison of inhibition of N2 fixation and ureide accumulation under water deficit in four common bean genotypes of contrasting drought tolerance. ANNALS OF BOTANY 2014; 113:1071-82. [PMID: 24638821 PMCID: PMC3997645 DOI: 10.1093/aob/mcu029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 02/12/2014] [Indexed: 05/21/2023]
Abstract
BACKGROUND AND AIMS Drought is the principal constraint on world production of legume crops. There is considerable variability among genotypes in sensitivity of nitrogen fixation to drought, which has been related to accumulation of ureides in soybean. The aim of this study was to search for genotypic differences in drought sensitivity and ureide accumulation in common bean (Phaseolus vulgaris) germplasm that may be useful in the improvement of tolerance to water deficit in common bean. METHODS Changes in response to water deficit of nitrogen fixation rates, ureide content and the expression and activity of key enzymes for ureide metabolism were measured in four P. vulgaris genotypes differing in drought tolerance. KEY RESULTS A variable degree of drought-induced nitrogen fixation inhibition was found among the bean genotypes. In addition to inhibition of nitrogen fixation, there was accumulation of ureides in stems and leaves of sensitive and tolerant genotypes, although this was higher in the leaves of the most sensitive ones. In contrast, there was no accumulation of ureides in the nodules or roots of stressed plants. In addition, the level of ureides in the most sensitive genotype increased after inhibition of nitrogen fixation, suggesting that ureides originate in vegetative tissues as a response to water stress, probably mediated by the induction of allantoinase. CONCLUSIONS Variability of drought-induced inhibition of nitrogen fixation among the P. vulgaris genotypes was accompanied by subsequent accumulation of ureides in stems and leaves, but not in nodules. The results indicate that shoot ureide accumulation after prolonged exposure to drought could not be the cause of inhibition of nitrogen fixation, as has been suggested in soybean. Instead, ureides seem to be produced as part of a general response to stress, and therefore higher accumulation might correspond to higher sensitivity to the stressful conditions.
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Affiliation(s)
- I. Coleto
- Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas del Campus de Excelencia Internacional Agroalimentario, CEIA3, Campus Rabanales, Edif. Severo Ochoa, 1 planta, Universidad de Córdoba, 14071 Córdoba, Spain
| | - M. Pineda
- Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas del Campus de Excelencia Internacional Agroalimentario, CEIA3, Campus Rabanales, Edif. Severo Ochoa, 1 planta, Universidad de Córdoba, 14071 Córdoba, Spain
| | - A. P. Rodiño
- Departamento de Recursos Fitogenéticos, Grupo de Biología de Agrosistemas, Misión Biológica de Galicia-CSIC, El Palacio-Salcedo, 36143 Pontevedra, Spain
| | - A. M. De Ron
- Departamento de Recursos Fitogenéticos, Grupo de Biología de Agrosistemas, Misión Biológica de Galicia-CSIC, El Palacio-Salcedo, 36143 Pontevedra, Spain
| | - J. M. Alamillo
- Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas del Campus de Excelencia Internacional Agroalimentario, CEIA3, Campus Rabanales, Edif. Severo Ochoa, 1 planta, Universidad de Córdoba, 14071 Córdoba, Spain
- For correspondence. E-mail
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Ivanov KI, Bašić M, Varjosalo M, Mäkinen K. One-step purification of twin-strep-tagged proteins and their complexes on strep-tactin resin cross-linked with bis(sulfosuccinimidyl) suberate (BS3). J Vis Exp 2014. [PMID: 24796313 DOI: 10.3791/51536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Affinity purification of Strep-tagged fusion proteins on resins carrying an engineered streptavidin (Strep-Tactin) has become a widely used method for isolation of protein complexes under physiological conditions. Fusion proteins containing two copies of Strep-tag II, designated twin-Strep-tag or SIII-tag, have the advantage of higher affinity for Strep-Tactin compared to those containing only a single Strep-tag, thus allowing more efficient protein purification. However, this advantage is offset by the fact that elution of twin-Strep-tagged proteins with biotin may be incomplete, leading to low protein recovery. The recovery can be dramatically improved by using denaturing elution with sodium dodecyl sulfate (SDS), but this leads to sample contamination with Strep-Tactin released from the resin, making the assay incompatible with downstream proteomic analysis. To overcome this limitation, we have developed a method whereby resin-coupled tetramer of Strep-Tactin is first stabilized by covalent cross-linking with Bis(sulfosuccinimidyl) suberate (BS3) and the resulting cross-linked resin is then used to purify target protein complexes in a single batch purification step. Efficient elution with SDS ensures good protein recovery, while the absence of contaminating Strep-Tactin allows downstream protein analysis by mass spectrometry. As a proof of concept, we describe here a protocol for purification of SIII-tagged viral protein VPg-Pro from nuclei of virus-infected N. benthamiana plants using the Strep-Tactin polymethacrylate resin cross-linked with BS3. The same protocol can be used to purify any twin-Strep-tagged protein of interest and characterize its physiological binding partners.
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Affiliation(s)
| | - Marta Bašić
- Department of Food and Environmental Sciences, University of Helsinki
| | | | - Kristiina Mäkinen
- Department of Food and Environmental Sciences, University of Helsinki;
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Tegeder M. Transporters involved in source to sink partitioning of amino acids and ureides: opportunities for crop improvement. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1865-78. [PMID: 24489071 DOI: 10.1093/jxb/eru012] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In most plant species, amino acids are the predominant chemical forms in which nitrogen is transported. However, in nodulated tropical or subtropical legumes, ureides are the main nitrogen transport compounds. This review describes the partitioning of amino acids and ureides within the plant, and follows their movement from the location of synthesis (source) to the sites of usage (sink). Xylem and phloem connect source and sink organs and serve as routes for long-distance transport of the organic nitrogen. Loading and unloading of these transport pathways might require movement of amino acids and ureides across cell membranes, a task that is mediated by membrane proteins (i.e. transporters) functioning as export or import systems. The current knowledge on amino acid and ureide transporters involved in long-distance transport of nitrogen is provided and their importance for source and sink physiology discussed. The review concludes by exploring possibilities for genetic manipulation of organic nitrogen transporter activities to confer increases in crop productivity.
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Affiliation(s)
- Mechthild Tegeder
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
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Watanabe S, Matsumoto M, Hakomori Y, Takagi H, Shimada H, Sakamoto A. The purine metabolite allantoin enhances abiotic stress tolerance through synergistic activation of abscisic acid metabolism. PLANT, CELL & ENVIRONMENT 2014; 37:1022-36. [PMID: 24182190 DOI: 10.1111/pce.12218] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 10/04/2013] [Indexed: 05/19/2023]
Abstract
Purine catabolism is regarded as a housekeeping function that remobilizes nitrogen for plant growth and development. However, emerging evidence suggests that certain purine metabolites might contribute to stress protection of plants. Here, we show that in Arabidopsis, the intermediary metabolite allantoin plays a role in abiotic stress tolerance via activation of abscisic acid (ABA) metabolism. The aln loss-of-function of ALN, encoding allantoinase, results in increased allantoin accumulation, genome-wide up-regulation of stress-related genes and enhanced tolerance to drought-shock and osmotic stress in aln mutant seedlings. This phenotype is not caused by a general response to purine catabolism inhibition, but rather results from a specific effect of allantoin. Allantoin activates ABA production both through increased transcription of NCED3, encoding a key enzyme in ABA biosynthesis, and through post-translational activation via high-molecular-weight complex formation of BG1, a β-glucosidase hydrolysing glucose-conjugated ABA. Exogenous application of allantoin to wild-type plants also activates the two ABA-producing pathways that lead to ABA accumulation and stress-responsive gene expression, but this effect is abrogated in ABA-deficient and BG1-knockout mutants. We propose that purine catabolism functions not only in nitrogen metabolism, but also in stress tolerance by influencing ABA production, which is mediated by the possible regulatory action of allantoin.
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Affiliation(s)
- Shunsuke Watanabe
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
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Dahncke K, Witte CP. Plant purine nucleoside catabolism employs a guanosine deaminase required for the generation of xanthosine in Arabidopsis. THE PLANT CELL 2013; 25:4101-9. [PMID: 24130159 PMCID: PMC3877791 DOI: 10.1105/tpc.113.117184] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/19/2013] [Accepted: 09/27/2013] [Indexed: 05/17/2023]
Abstract
Purine nucleotide catabolism is common to most organisms and involves a guanine deaminase to convert guanine to xanthine in animals, invertebrates, and microorganisms. Using metabolomic analysis of mutants, we demonstrate that Arabidopsis thaliana uses an alternative catabolic route employing a highly specific guanosine deaminase (GSDA) not reported from any organism so far. The enzyme is ubiquitously expressed and deaminates exclusively guanosine and 2'-deoxyguanosine but no other aminated purines, pyrimidines, or pterines. GSDA belongs to the cytidine/deoxycytidylate deaminase family of proteins together with a deaminase involved in riboflavin biosynthesis, the chloroplastic tRNA adenosine deaminase Arg and a predicted tRNA-specific adenosine deaminase 2 in A. thaliana. GSDA is conserved in plants, including the moss Physcomitrella patens, but is absent in the algae and outside the plant kingdom. Our data show that xanthosine is exclusively generated through the deamination of guanosine by GSDA in A. thaliana, excluding other possible sources like the dephosphorylation of xanthosine monophosphate. Like the nucleoside hydrolases NUCLEOSIDE HYDROLASE1 (NSH1) and NSH2, GSDA is located in the cytosol, indicating that GMP catabolism to xanthine proceeds in a mostly cytosolic pathway via guanosine and xanthosine. Possible implications for the biosynthetic route of purine alkaloids (caffeine and theobromine) and ureides in other plants are discussed.
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Werner AK, Medina-Escobar N, Zulawski M, Sparkes IA, Cao FQ, Witte CP. The ureide-degrading reactions of purine ring catabolism employ three amidohydrolases and one aminohydrolase in Arabidopsis, soybean, and rice. PLANT PHYSIOLOGY 2013; 163:672-81. [PMID: 23940254 PMCID: PMC3793049 DOI: 10.1104/pp.113.224261] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 08/11/2013] [Indexed: 05/19/2023]
Abstract
Several ureides are intermediates of purine base catabolism, releasing nitrogen from the purine nucleotides for reassimilation into amino acids. In some legumes like soybean (Glycine max), ureides are used for nodule-to-shoot translocation of fixed nitrogen. Four enzymes of Arabidopsis (Arabidopsis thaliana), (1) allantoinase, (2) allantoate amidohydrolase (AAH), (3) ureidoglycine aminohydrolase, and (4) ureidoglycolate amidohydrolase (UAH), catalyze the complete hydrolysis of the ureide allantoin in vitro. However, the metabolic route in vivo remains controversial. Here, in growth and metabolite analyses of Arabidopsis mutants, we demonstrate that these enzymes are required for allantoin degradation in vivo. Orthologous enzymes are present in soybean, encoded by one to four gene copies. All isoenzymes are active in vitro, while some may be inefficiently translated in vivo. Surprisingly, transcript and protein amounts are not significantly regulated by nitrogen fixation or leaf ureide content. A requirement for soybean AAH and UAH for ureide catabolism in leaves has been demonstrated by the use of virus-induced gene silencing. Functional AAH, ureidoglycine aminohydrolase, and UAH are also present in rice (Oryza sativa), and orthologous genes occur in all other plant genomes sequenced to date, indicating that the amidohydrolase route of ureide degradation is universal in plants, including mosses (e.g. Physcomitrella patens) and algae (e.g. Chlamydomomas reinhardtii).
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Affiliation(s)
| | | | - Monika Zulawski
- Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, 14195 Berlin, Germany (A.K.W., N.M.-E., M.Z., F.-Q.C., C.-P.W.); and
- Oxford Brookes University, School of Life Sciences, Oxford OX3 0BP, United Kingdom (I.A.S.)
| | | | - Feng-Qiu Cao
- Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, 14195 Berlin, Germany (A.K.W., N.M.-E., M.Z., F.-Q.C., C.-P.W.); and
- Oxford Brookes University, School of Life Sciences, Oxford OX3 0BP, United Kingdom (I.A.S.)
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Hoepflinger MC, Reitsamer J, Geretschlaeger AM, Mehlmer N, Tenhaken R. The effect of translationally controlled tumour protein (TCTP) on programmed cell death in plants. BMC PLANT BIOLOGY 2013; 13:135. [PMID: 24040826 PMCID: PMC3847524 DOI: 10.1186/1471-2229-13-135] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 09/12/2013] [Indexed: 05/25/2023]
Abstract
BACKGROUND Translationally controlled tumour protein (TCTP), a well known protein of the animal kingdom, was shown to be a Ca(2+)-binding protein with important functions in many different cellular processes (e.g. protection against stress and apoptosis, cell growth, cell cycle progression, and microtubule organization). However, only little is known about TCTP in plants. Transcript and protein levels of plant TCTPs were shown to be altered by various stress conditions (e.g. cold, salt, draught, aluminium, and pathogen infection), and Arabidopsis thaliana TCTP (AtTCTP) was described as an important regulator of growth. The aim of this study was to further characterize plant TCTP relating to one of its major functions in animals: the protection against cell death. RESULTS We used two different activators of programmed cell death (PCD) in plants: the mammalian pro-apoptotic protein BAX and tunicamycin, an inhibitor of glycosylation and trigger of unfolded protein response (UPR). Over-expression of AtTCTP significantly decreased cell death in tobacco leaf discs in both studies. A (45)Ca overlay assay showed AtTCTP to be a Ca(2+)-binding protein and localization experiments revealed cytosolic distribution of AtTCTP-GFP in Arabidopsis seedlings. CONCLUSIONS Our study showed cytoprotective effects of plant TCTP for the first time. Furthermore, we showed the ability of AtTCTP to bind to Ca(2+) and its cytosolic distribution within the cell. If these results are combined, two putative modes of action can be assumed: 1) AtTCTP acts as Ca(2+) sequester, preventing PCD by reducing cytosolic Ca(2+) levels as described for animals. 2) AtTCTP could directly or indirectly interact with other cytosolic or membrane-bound proteins of the cell death machinery, thereby inhibiting cell death progression. As no homologous proteins of the anti-apoptotic machinery of animals were found in plants, and functional homologues still remain to be elucidated, future work will provide more insight.
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Affiliation(s)
- Marion Christine Hoepflinger
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, Hellbrunnerstraße 34, 5020 Salzburg, Austria
| | - Johannes Reitsamer
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, Hellbrunnerstraße 34, 5020 Salzburg, Austria
| | - Anja Maria Geretschlaeger
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, Hellbrunnerstraße 34, 5020 Salzburg, Austria
| | - Norbert Mehlmer
- Department of Biology I, Botany, LMU Munich, 82152 Martinsried, Germany
| | - Raimund Tenhaken
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, Hellbrunnerstraße 34, 5020 Salzburg, Austria
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HylA, an alternative hydrolase for initiation of catabolism of the phenylurea herbicide linuron in Variovorax sp. strains. Appl Environ Microbiol 2013; 79:5258-63. [PMID: 23811502 DOI: 10.1128/aem.01478-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Variovorax sp. strain WDL1, which mineralizes the phenylurea herbicide linuron, expresses a novel linuron-hydrolyzing enzyme, HylA, that converts linuron to 3,4-dichloroaniline (DCA). The enzyme is distinct from the linuron hydrolase LibA enzyme recently identified in other linuron-mineralizing Variovorax strains and from phenylurea-hydrolyzing enzymes (PuhA, PuhB) found in Gram-positive bacteria. The dimeric enzyme belongs to a separate family of hydrolases and differs in Km, temperature optimum, and phenylurea herbicide substrate range. Within the metal-dependent amidohydrolase superfamily, HylA and PuhA/PuhB belong to two distinct protein families, while LibA is a member of the unrelated amidase signature family. The hylA gene was identified in a draft genome sequence of strain WDL1. The involvement of hylA in linuron degradation by strain WDL1 is inferred from its absence in spontaneous WDL1 mutants defective in linuron hydrolysis and its presence in linuron-degrading Variovorax strains that lack libA. In strain WDL1, the hylA gene is combined with catabolic gene modules encoding the downstream pathways for DCA degradation, which are very similar to those present in Variovorax sp. SRS16, which contains libA. Our results show that the expansion of a DCA catabolic pathway toward linuron degradation in Variovorax can involve different but isofunctional linuron hydrolysis genes encoding proteins that belong to evolutionary unrelated hydrolase families. This may be explained by divergent evolution and the independent acquisition of the corresponding genetic modules.
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Lee IR, Yang L, Sebetso G, Allen R, Doan THN, Blundell R, Lui EYL, Morrow CA, Fraser JA. Characterization of the complete uric acid degradation pathway in the fungal pathogen Cryptococcus neoformans. PLoS One 2013; 8:e64292. [PMID: 23667704 PMCID: PMC3646786 DOI: 10.1371/journal.pone.0064292] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 04/10/2013] [Indexed: 01/08/2023] Open
Abstract
Degradation of purines to uric acid is generally conserved among organisms, however, the end product of uric acid degradation varies from species to species depending on the presence of active catabolic enzymes. In humans, most higher primates and birds, the urate oxidase gene is non-functional and hence uric acid is not further broken down. Uric acid in human blood plasma serves as an antioxidant and an immune enhancer; conversely, excessive amounts cause the common affliction gout. In contrast, uric acid is completely degraded to ammonia in most fungi. Currently, relatively little is known about uric acid catabolism in the fungal pathogen Cryptococcus neoformans even though this yeast is commonly isolated from uric acid-rich pigeon guano. In addition, uric acid utilization enhances the production of the cryptococcal virulence factors capsule and urease, and may potentially modulate the host immune response during infection. Based on these important observations, we employed both Agrobacterium-mediated insertional mutagenesis and bioinformatics to predict all the uric acid catabolic enzyme-encoding genes in the H99 genome. The candidate C. neoformans uric acid catabolic genes identified were named: URO1 (urate oxidase), URO2 (HIU hydrolase), URO3 (OHCU decarboxylase), DAL1 (allantoinase), DAL2,3,3 (allantoicase-ureidoglycolate hydrolase fusion protein), and URE1 (urease). All six ORFs were then deleted via homologous recombination; assaying of the deletion mutants' ability to assimilate uric acid and its pathway intermediates as the sole nitrogen source validated their enzymatic functions. While Uro1, Uro2, Uro3, Dal1 and Dal2,3,3 were demonstrated to be dispensable for virulence, the significance of using a modified animal model system of cryptococcosis for improved mimicking of human pathogenicity is discussed.
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Affiliation(s)
- I. Russel Lee
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Liting Yang
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Gaseene Sebetso
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Rebecca Allen
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Thi H. N. Doan
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Ross Blundell
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Edmund Y. L. Lui
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Carl A. Morrow
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - James A. Fraser
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
- * E-mail:
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Töpfer N, Caldana C, Grimbs S, Willmitzer L, Fernie AR, Nikoloski Z. Integration of genome-scale modeling and transcript profiling reveals metabolic pathways underlying light and temperature acclimation in Arabidopsis. THE PLANT CELL 2013; 25:1197-211. [PMID: 23613196 PMCID: PMC3663262 DOI: 10.1105/tpc.112.108852] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 03/18/2013] [Accepted: 04/05/2013] [Indexed: 05/21/2023]
Abstract
Understanding metabolic acclimation of plants to challenging environmental conditions is essential for dissecting the role of metabolic pathways in growth and survival. As stresses involve simultaneous physiological alterations across all levels of cellular organization, a comprehensive characterization of the role of metabolic pathways in acclimation necessitates integration of genome-scale models with high-throughput data. Here, we present an integrative optimization-based approach, which, by coupling a plant metabolic network model and transcriptomics data, can predict the metabolic pathways affected in a single, carefully controlled experiment. Moreover, we propose three optimization-based indices that characterize different aspects of metabolic pathway behavior in the context of the entire metabolic network. We demonstrate that the proposed approach and indices facilitate quantitative comparisons and characterization of the plant metabolic response under eight different light and/or temperature conditions. The predictions of the metabolic functions involved in metabolic acclimation of Arabidopsis thaliana to the changing conditions are in line with experimental evidence and result in a hypothesis about the role of homocysteine-to-Cys interconversion and Asn biosynthesis. The approach can also be used to reveal the role of particular metabolic pathways in other scenarios, while taking into consideration the entirety of characterized plant metabolism.
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Affiliation(s)
- Nadine Töpfer
- Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Camila Caldana
- Brazilian Bioethanol Science and Technology Laboratory, Integrate Brazilian Center of Research in Energy and Materials, Associated Centers to the Brazilian Association for Synchrotron Light Technology, 13083-970 Campinas, Brazil
| | - Sergio Grimbs
- Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany
| | - Lothar Willmitzer
- Genes and Small Molecules Group, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Alisdair R. Fernie
- Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Zoran Nikoloski
- Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Address correspondence to
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Hacquard S, Tisserant E, Brun A, Legué V, Martin F, Kohler A. Laser microdissection and microarray analysis of Tuber melanosporum ectomycorrhizas reveal functional heterogeneity between mantle and Hartig net compartments. Environ Microbiol 2013; 15:1853-69. [PMID: 23379715 DOI: 10.1111/1462-2920.12080] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/27/2012] [Indexed: 02/02/2023]
Abstract
The ectomycorrhizal (ECM) symbiosis, a mutualistic plant-fungus association, plays a fundamental role in forest ecosystems by enhancing plant growth and by providing host protection from root diseases. The cellular complexity of the symbiotic organ, characterized by the differentiation of structurally specialized tissues (i.e. the fungal mantle and the Hartig net), is the major limitation to study fungal gene expression in such specific compartments. We investigated the transcriptional landscape of the ECM fungus Tuber melanosporum during the major stages of its life cycle and we particularly focused on the complex symbiotic stage by combining the use of laser capture microdissection and microarray gene expression analysis. We isolated the fungal/soil (i.e. the mantle) and the fungal/plant (i.e. the Hartig net) interfaces from transverse sections of T. melanosporum/Corylus avellana ectomycorrhizas and identified the distinct genetic programmes associated with each compartment. Particularly, nitrogen and water acquisition from soil, synthesis of secondary metabolites and detoxification mechanisms appear to be important processes in the fungal mantle. In contrast, transport activity is enhanced in the Hartig net and we identified carbohydrate and nitrogen-derived transporters that might play a key role in the reciprocal resources' transfer between the host and the symbiont.
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Affiliation(s)
- Stéphane Hacquard
- UMR 1136 INRA/Université de Lorraine, Interactions Arbres/Micro-organismes, INRA, Institut National de la Recherche Agronomique, Centre INRA de Nancy, 54280 Champenoux, France
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Polacco JC, Mazzafera P, Tezotto T. Opinion: nickel and urease in plants: still many knowledge gaps. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 199-200:79-90. [PMID: 23265321 DOI: 10.1016/j.plantsci.2012.10.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 10/19/2012] [Accepted: 10/20/2012] [Indexed: 05/22/2023]
Abstract
We propose experimental strategies to expand our understanding of the role of Ni in plants, beyond the Ni-metallocenter of urease, still the only identified Ni-containing plant enzyme. While Ni has been considered an essential mineral for plants there is a clear lack of knowledge of its involvement in metabolic steps except the urease-catalyzed conversion of urea to ammonia and bicarbonate. We argue that urease (and hence, Ni) plays an important role in optimal N-use efficiency under various N regimes by recycling urea-N, which is generated endogenously exclusively from arginase action on arginine. We further suggest that urease and arginase may connect different metabolic compartments under stress situations, and therefore may be involved in stress tolerance. To determine possible non-urease roles of Ni we call for experimental manipulation of both Ni and N availability in urease-negative mutants. Plant ureases have been shown to have defense roles, distinct from their ureolytic activity, and we call for investigation of whether Ni helps maintain a urease conformation or stability for these non-ureolytic defense roles. The beneficial effects of Ni at upper concentration limits have not been fully examined. We posit a "Ni strategy" of plants whose growth/performance is stimulated by unusual amounts of soil Ni, for defense and/or for maximal N-use efficiency. While we know little about Ni and urease roles in N metabolism and defense, virtually nothing is known about Ni roles in plant-microbial 'consortia.' And, much of what we know of Ni and urease is limited to only a few plants, e.g. soybean, potato and Arabidopsis, and we suggest studies vigorously extended to other plants.
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Affiliation(s)
- Joe C Polacco
- University of Missouri, Department of Biochemistry, Interdisciplinary Plant Group, Columbia, MO 65211, United States.
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Collier R, Tegeder M. Soybean ureide transporters play a critical role in nodule development, function and nitrogen export. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 72:355-67. [PMID: 22725647 DOI: 10.1111/j.1365-313x.2012.05086.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Legumes can access atmospheric nitrogen through a symbiotic relationship with nitrogen-fixing bacteroids that reside in root nodules. In soybean, the products of fixation are the ureides allantoin and allantoic acid, which are also the dominant long-distance transport forms of nitrogen from nodules to the shoot. Movement of nitrogen assimilates out of the nodules occurs via the nodule vasculature; however, the molecular mechanisms for ureide export and the importance of nitrogen transport processes for nodule physiology have not been resolved. Here, we demonstrate the function of two soybean proteins - GmUPS1-1 (XP_003516366) and GmUPS1-2 (XP_003518768) - in allantoin and allantoic acid transport out of the nodule. Localization studies revealed the presence of both transporters in the plasma membrane, and expression in nodule cortex cells and vascular endodermis. Functional analysis in soybean showed that repression of GmUPS1-1 and GmUPS1-2 in nodules leads to an accumulation of ureides and decreased nitrogen partitioning to roots and shoot. It was further demonstrated that nodule development, nitrogen fixation and nodule metabolism were negatively affected in RNAi UPS1 plants. Together, we conclude that export of ureides from nodules is mediated by UPS1 proteins, and that activity of the transporters is not only essential for shoot nitrogen supply but also for nodule development and function.
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Affiliation(s)
- Ray Collier
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
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