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Aguirre-Sampieri S, Casañal A, Emsley P, Garza-Ramos G. Cryo-EM structure of bacterial nitrilase reveals insight into oligomerization, substrate recognition, and catalysis. J Struct Biol 2024; 216:108093. [PMID: 38615726 PMCID: PMC7616060 DOI: 10.1016/j.jsb.2024.108093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/26/2024] [Accepted: 04/12/2024] [Indexed: 04/16/2024]
Abstract
Many enzymes can self-assemble into higher-order structures with helical symmetry. A particularly noteworthy example is that of nitrilases, enzymes in which oligomerization of dimers into spiral homo-oligomers is a requirement for their enzymatic function. Nitrilases are widespread in nature where they catalyze the hydrolysis of nitriles into the corresponding carboxylic acid and ammonia. Here, we present the Cryo-EM structure, at 3 Å resolution, of a C-terminal truncate nitrilase from Rhodococcus sp. V51B that assembles in helical filaments. The model comprises a complete turn of the helical arrangement with a substrate-intermediate bound to the catalytic cysteine. The structure was solved having added the substrate to the protein. The length and stability of filaments was made more substantial in the presence of the aromatic substrate, benzonitrile, but not for aliphatic nitriles or dinitriles. The overall structure maintains the topology of the nitrilase family, and the filament is formed by the association of dimers in a chain-like mechanism that stabilizes the spiral. The active site is completely buried inside each monomer, while the substrate binding pocket was observed within the oligomerization interfaces. The present structure is in a closed configuration, judging by the position of the lid, suggesting that the intermediate is one of the covalent adducts. The proximity of the active site to the dimerization and oligomerization interfaces, allows the dimer to sense structural changes once the benzonitrile was bound, and translated to the rest of the filament, stabilizing the helical structure.
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Affiliation(s)
- Sergio Aguirre-Sampieri
- Universidad Nacional Autónoma de México, Facultad de Medicina, Departamento de Bioquímica, Circuito Escolar S/N, Ciudad Universitaria, CDMX, Mexico
| | - Ana Casañal
- Human Technopole, Palazzo Italia, Viale Rita Levi‑Montalcini, 1, 20157 Milan, Italy
| | - Paul Emsley
- MRC Laboratory of Molecular Biology, Structural Studies Division, Francis Crick Avenue, CB2 0QH Cambridge, England
| | - Georgina Garza-Ramos
- Universidad Nacional Autónoma de México, Facultad de Medicina, Departamento de Bioquímica, Circuito Escolar S/N, Ciudad Universitaria, CDMX, Mexico.
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2
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Wu B, Xia Y, Zhang G, Wang Y, Wang J, Ma S, Song Y, Yang Z, Ma L, Niu N. Transcriptomics reveals a core transcriptional network of K-type cytoplasmic male sterility microspore abortion in wheat (Triticum aestivum L.). BMC PLANT BIOLOGY 2023; 23:618. [PMID: 38057735 DOI: 10.1186/s12870-023-04611-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 11/15/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND Cytoplasmic male sterility (CMS) plays a crucial role in hybrid production. K-type CMS, a cytoplasmic male sterile line of wheat with the cytoplasms of Aegilops kotschyi, is widely used due to its excellent characteristics of agronomic performance, easy maintenance and easy restoration. However, the mechanism of its pollen abortion is not yet clear. RESULTS In this study, wheat K-type CMS MS(KOTS)-90-110 (MS line) and it's fertile near-isogenic line MR (KOTS)-90-110 (MR line) were investigated. Cytological analysis indicated that the anthers of MS line microspore nucleus failed to divide normally into two sperm nucleus and lacked starch in mature pollen grains, and the key abortive period was the uninucleate stage to dinuclear stage. Then, we compared the transcriptome of MS line and MR line anthers at these two stages. 11,360 and 5182 differentially expressed genes (DEGs) were identified between the MS and MR lines in the early uninucleate and binucleate stages, respectively. Based on GO enrichment and KEGG pathways analysis, it was evident that significant transcriptomic differences were "plant hormone signal transduction", "MAPK signaling pathway" and "spliceosome". We identified 17 and 10 DEGs associated with the IAA and ABA signal transduction pathways, respectively. DEGs related to IAA signal transduction pathway were downregulated in the early uninucleate stage of MS line. The expression level of DEGs related to ABA pathway was significantly upregulated in MS line at the binucleate stage compared to MR line. The determination of plant hormone content and qRT-PCR further confirmed that hormone imbalance in MS lines. Meanwhile, 1 and 2 DEGs involved in ABA and Ethylene metabolism were also identified in the MAPK cascade pathway, respectively; the significant up regulation of spliceosome related genes in MS line may be another important factor leading to pollen abortion. CONCLUSIONS We proposed a transcriptome-mediated pollen abortion network for K-type CMS in wheat. The main idea is hormone imbalance may be the primary factor, MAPK cascade pathway and alternative splicing (AS) may also play important regulatory roles in this process. These findings provided intriguing insights for the molecular mechanism of microspore abortion in K-type CMS, and also give useful clues to identify the crucial genes of CMS in wheat.
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Affiliation(s)
- Baolin Wu
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
| | - Yu Xia
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Gaisheng Zhang
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
| | - Yongqing Wang
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
| | - Junwei Wang
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
| | - Shoucai Ma
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
| | - Yulong Song
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
| | - Zhiquan Yang
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China
| | - Lingjian Ma
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China.
| | - Na Niu
- College of Agronomy, Northwest A & F University, Key Laboratory of Crop Heterosis of Shaanxi Province, Wheat Breeding Engineering Research Center, Ministry of Education, Yangling, 712100, Shaanxi, China.
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3
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Schwartz SL, Rangel LT, Payette JG, Fournier GP. A Proterozoic microbial origin of extant cyanide-hydrolyzing enzyme diversity. Front Microbiol 2023; 14:1130310. [PMID: 37065136 PMCID: PMC10098168 DOI: 10.3389/fmicb.2023.1130310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/07/2023] [Indexed: 04/03/2023] Open
Abstract
In addition to its role as a toxic environmental contaminant, cyanide has been hypothesized to play a key role in prebiotic chemistry and early biogeochemical evolution. While cyanide-hydrolyzing enzymes have been studied and engineered for bioremediation, the extant diversity of these enzymes remains underexplored. Additionally, the age and evolution of microbial cyanide metabolisms is poorly constrained. Here we provide comprehensive phylogenetic and molecular clock analyses of the distribution and evolution of the Class I nitrilases, thiocyanate hydrolases, and nitrile hydratases. Molecular clock analyses indicate that bacterial cyanide-reducing nitrilases were present by the Paleo- to Mesoproterozoic, and were subsequently horizontally transferred into eukaryotes. These results present a broad diversity of microbial enzymes that could be optimized for cyanide bioremediation.
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Affiliation(s)
- Sarah L. Schwartz
- Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States
- Graduate Program in Microbiology, Massachusetts Institute of Technology, Cambridge, MA, United States
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
- *Correspondence: Sarah L. Schwartz,
| | - L. Thiberio Rangel
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Jack G. Payette
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Gregory P. Fournier
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
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Sunic K, D’Auria JC, Sarkanj B, Spanic V. Metabolic Profiling Identifies Changes in the Winter Wheat Grains Following Fusarium Treatment at Two Locations in Croatia. PLANTS (BASEL, SWITZERLAND) 2023; 12:911. [PMID: 36840259 PMCID: PMC9962043 DOI: 10.3390/plants12040911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Fusarium head blight (FHB) is one of the most dangerous diseases of winter wheat, resulting in reduced grain yield and quality, and production of mycotoxins by the Fusarium fungi. In the present study, changes in the grain metabolomics of winter wheat samples infected with Fusarium spp. and corresponding non-infected samples from two locations in Croatia were investigated by GC-MS. A Mann-Whitney test revealed that 24 metabolites detected were significantly separated between Fusarium-inoculated and non-infected samples during the variety by treatment interactions. The results confirmed that in grains of six FHB-resistant varieties, ten metabolites were identified as possible resistance-related metabolites. These metabolites included heptadecanoic acid, 9-(Z)-hexadecenoic acid, sophorose, and secolaganin in grains of FHB-resistant varieties at the Osijek location, as well as 2-methylaminomethyltartronic acid, maleamic acid, 4-hydroxyphenylacetonitrile, 1,4-lactonearabinonic acid, secolaganin, and alanine in grains of FHB-resistant varieties at the Tovarnik location. Moreover, on the PCA bi-plot, FHB-susceptible wheat varieties were closer to glycyl proline, decanoic acid, and lactic acid dimer that could have affected other metabolites, and thus, suppressed resistance to FHB. Although defense reactions were genetically conditioned and variety specific, resulting metabolomics changes may give insight into defense-related pathways that could be manipulated to engineer plants with improved resistance to the pathogen.
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Affiliation(s)
- Katarina Sunic
- Department for Breeding and Genetics of Small Cereal Crops, Agricultural Institute Osijek, Juzno Predgradje 17, 31000 Osijek, Croatia
| | - John Charles D’Auria
- Department of Molecular Genetics Leibniz, Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben), OT Gatersleben Corrensstraße 3, 06466 Seeland, Germany
| | - Bojan Sarkanj
- Department of Food Technology, University North, Trg dr. Zarka Dolinara 1, 48000 Koprivnica, Croatia
| | - Valentina Spanic
- Department for Breeding and Genetics of Small Cereal Crops, Agricultural Institute Osijek, Juzno Predgradje 17, 31000 Osijek, Croatia
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Salwan R, Sharma V, Das S. Phylogenetic and Structural Analysis of Bacterial Nitrilases for the Biodegradation of Nitrile Compounds. Curr Protein Pept Sci 2022; 23:874-882. [PMID: 36154580 DOI: 10.2174/1389203723666220921154409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 04/05/2022] [Accepted: 04/12/2022] [Indexed: 01/20/2023]
Abstract
BACKGROUND Microbial nitrilases play a vital role in the biodegradation of nitrilecontaining pollutants, effluent treatments in chemical and textile industries, and the biosynthesis of Indole-3-acetic acid (IAA) from tryptophan in plants. However, the lack of structural information limits the correlation between its activity and substrate specificity. METHODS The present study involves the genome mining of bacteria for the distribution and diversity of nitrilases, their phylogenetic analysis and structural characterization for motifs/ domains, followed by interaction with substrates. RESULTS Here, we mined the bacterial genomes for nitrilases and correlated their functions to hypothetical, uncharacterized, or putative ones. The comparative genomics revealed four AcNit, As7Nit, Cn5Nit and Cn9Nit predicted nitrilases encoding genes as uncharacterized subgroups of the nitrilase superfamily. The annotation of these nitrilases encoding genes revealed relatedness with nitrilase hydratases and cyanoalanine hydratases. At the proteomics level, the motif analysis of these protein sequences predicted a single motif of 20-28 aa, with glutamate (E), lysine (K) and cysteine (C) residues as a part of catalytic triad along with several other residues at the active site. The structural analysis of the nitrilases revealed geometrical and close conformation in the form of α-helices and β-sheets arranged in a sandwich structure. The catalytic residues constituted the substrate binding pocket and exhibited the broad nitrile substrate spectra for aromatic and aliphatic nitriles-containing compounds. The aromatic amino acid residues Y159 in the active site were predicted to be responsible for substrate specificity. The substitution of non-aromatic alanine residue in place of Y159 completely disrupted the catalytic activity for indole-3-acetonitrile (IAN). CONCLUSION The present study reports genome mining and simulation of structure-function relationship for uncharacterized bacterial nitrilases and their role in the biodegradation of pollutants and xenobiotics, which could be of applications in different industrial sectors.
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Affiliation(s)
- Richa Salwan
- College of Horticulture and Forestry (Dr. YS Parmar University of Horticulture and Forestry), Neri, Hamirpur (HP)- 177 001, India
| | - Vivek Sharma
- University Centre for Research and Development, Chandigarh University (PB)-140413, India
| | - Surajit Das
- Department of Life Science, Laboratory of Environmental Microbiology and Ecology (LEnME), National Institute of Technology Rourkela, Rourkela- 769 008, Odisha, India
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Vaishnav A, Kumar R, Singh HB, Sarma BK. Extending the benefits of PGPR to bioremediation of nitrile pollution in crop lands for enhancing crop productivity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 826:154170. [PMID: 35227717 DOI: 10.1016/j.scitotenv.2022.154170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/06/2022] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
Incessant release of nitrile group of compounds such as cyanides into agricultural land through industrial effluents and excessive use of nitrile pesticides has resulted in increased nitrile pollution. Release of nitrile compounds (NCs) as plant root exudates is also contributing to the problem. The released NCs interact with soil elements and persists for a long time. Persistent higher concentration of NCs in soil cause toxicity to beneficial microflora and affect crop productivity. The NCs can cause more problems to human health if they reach groundwater and enter the food chain. Nitrile degradation by soil bacteria can be a solution to the problem if thoroughly exploited. However, the impact of such bacteria in plant and soil environments is still not properly explored. Plant growth-promoting rhizobacteria (PGPR) with nitrilase activity has recently gained attention as potential solution to address the problem. This paper reviews the core issue of nitrile pollution in soil and the prospects of application of nitrile degrading bacteria for soil remediation, soil health improvement and plant growth promotion in nitrile-polluted soils. The possible mechanisms of PGPR that can be exploited to degrade NCs, converting them into plant useful compounds and synthesis of the phytohormone IAA from degraded NCs are also discussed at length.
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Affiliation(s)
- Anukool Vaishnav
- Department of Biotechnology, GLA University, Mathura 281406, India; Agroecology and Environment, Agroscope (Reckenholz), Zürich 8046, Switzerland
| | - Roshan Kumar
- National Centre for Biological Sciences (TIFR-NCBS), Bengaluru 560065, India
| | | | - Birinchi Kumar Sarma
- Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221110, India.
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7
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Zhang H, Zhang H, Qin X, Wang X, Wang Y, Tu T, Wang Y, Yao B, Huang H, Luo H. Biodegradation of nitriles derived from glucosinolates in rapeseed meal by BnNIT2: a nitrilase from Brassica napus with wide substrate specificity. Appl Microbiol Biotechnol 2022; 106:2445-2454. [PMID: 35262786 DOI: 10.1007/s00253-022-11844-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/15/2022] [Accepted: 02/19/2022] [Indexed: 11/02/2022]
Abstract
Nitriles derived from glucosinolates (GSLs) in rapeseed meal (RSM) can cause lesions on animal liver and kidneys. Nitrilase converts nitriles to carboxylic acids and NH3, eliminating their toxicity. Here we describe a nitrilase, BnNIT2, from Brassica napus (optimal temperature, 45 °C; pH, 7.0) that is stable at 40 °C and has a wide substrate specificity. Recombinant BnNIT2 converted the three main nitriles from GSLs (3-hydroxy-4-pentenenitrile, 3-butenenitrile, and 4-pentenenitrile), with the highest specific activity (58.6 U/mg) for 4-pentenenitrile. We used mutagenesis to improve the thermostability of BnNIT2; the resulting mutant BnNIT2-H90M had an ~ 14.5% increase in residual activity at 50 °C for 1 h. To verify the functionality of BnNIT2, GSLs were extracted from RSM and converted into nitriles at pH 5.0 in the presence of Fe2+. Then, BnNIT2 was used to degrade the nitriles from GSLs; ultimately, ~ 80% of nitriles were removed. Thus BnNIT2 is a potential enzyme for detoxification of RSM. KEY POINTS: • Functional identification of the plant nitrilase BnNIT2. • Identified a mutant, H90M, with improved thermostability. • BnNIT2 was capable of degrading nitriles from transformed GSLs.
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Affiliation(s)
- Heng Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Honghai Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Xing Qin
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Yaru Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
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Rädisch R, Pátek M, Křístková B, Winkler M, Křen V, Martínková L. Metabolism of Aldoximes and Nitriles in Plant-Associated Bacteria and Its Potential in Plant-Bacteria Interactions. Microorganisms 2022; 10:549. [PMID: 35336124 PMCID: PMC8955678 DOI: 10.3390/microorganisms10030549] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 11/22/2022] Open
Abstract
In plants, aldoximes per se act as defense compounds and are precursors of complex defense compounds such as cyanogenic glucosides and glucosinolates. Bacteria rarely produce aldoximes, but some are able to transform them by aldoxime dehydratase (Oxd), followed by nitrilase (NLase) or nitrile hydratase (NHase) catalyzed transformations. Oxds are often encoded together with NLases or NHases in a single operon, forming the aldoxime-nitrile pathway. Previous reviews have largely focused on the use of Oxds and NLases or NHases in organic synthesis. In contrast, the focus of this review is on the contribution of these enzymes to plant-bacteria interactions. Therefore, we summarize the substrate specificities of the enzymes for plant compounds. We also analyze the taxonomic and ecological distribution of the enzymes. In addition, we discuss their importance in selected plant symbionts. The data show that Oxds, NLases, and NHases are abundant in Actinobacteria and Proteobacteria. The enzymes seem to be important for breaking through plant defenses and utilizing oximes or nitriles as nutrients. They may also contribute, e.g., to the synthesis of the phytohormone indole-3-acetic acid. We conclude that the bacterial and plant metabolism of aldoximes and nitriles may interfere in several ways. However, further in vitro and in vivo studies are needed to better understand this underexplored aspect of plant-bacteria interactions.
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Affiliation(s)
- Robert Rädisch
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20 Prague, Czech Republic
- Department of Genetics and Microbiology, Faculty of Sciences, Charles University, Viničná 5, CZ-128 44 Prague, Czech Republic
| | - Miroslav Pátek
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20 Prague, Czech Republic
| | - Barbora Křístková
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20 Prague, Czech Republic
- Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Technická 5, CZ-166 28 Prague, Czech Republic
| | - Margit Winkler
- Institute of Molecular Biotechnology, Faculty of Technical Chemistry, Chemical and Process Engineering, Biotechnology, Graz University of Technology, Petersgasse 14, A-8010 Graz, Austria
- Austrian Center of Industrial Biotechnology GmbH, Krenngasse 37, A-8010 Graz, Austria
| | - Vladimír Křen
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20 Prague, Czech Republic
| | - Ludmila Martínková
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20 Prague, Czech Republic
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Daneshian L, Renggli I, Hanaway R, Offermann LR, Schlachter CR, Hernandez Arriaza R, Henry S, Prakash R, Wybouw N, Dermauw W, Shimizu LS, Van Leeuwen T, Makris TM, Grbic V, Grbic M, Chruszcz M. Structural and functional characterization of β-cyanoalanine synthase from Tetranychus urticae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 142:103722. [PMID: 35063675 DOI: 10.1016/j.ibmb.2022.103722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Tetranychus urticae is a polyphagous spider mite that can feed on more than 1100 plant species including cyanogenic plants. The herbivore genome contains a horizontally acquired gene tetur10g01570 (TuCAS) that was previously shown to participate in cyanide detoxification. To understand the structure and determine the function of TuCAS in T. urticae, crystal structures of the protein with lysine conjugated pyridoxal phosphate (PLP) were determined. These structures reveal extensive TuCAS homology with the β-substituted alanine synthase family, and they show that this enzyme utilizes a similar chemical mechanism involving a stable α-aminoacrylate intermediate in β-cyanoalanine and cysteine synthesis. We demonstrate that TuCAS is more efficient in the synthesis of β-cyanoalanine, which is a product of the detoxification reaction between cysteine and cyanide, than in the biosynthesis of cysteine. Also, the enzyme carries additional enzymatic activities that were not previously described. We show that TuCAS can detoxify cyanide using O-acetyl-L-serine as a substrate, leading to the direct formation of β-cyanoalanine. Moreover, it catalyzes the reaction between the TuCAS-bound α-aminoacrylate intermediate and aromatic compounds with a thiol group. In addition, we have tested several compounds as TuCAS inhibitors. Overall, this study identifies additional functions for TuCAS and provides new molecular insight into the xenobiotic metabolism of T. urticae.
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Affiliation(s)
- Leily Daneshian
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Isabella Renggli
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Ryan Hanaway
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Lesa R Offermann
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Caleb R Schlachter
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | | | - Shannon Henry
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Rahul Prakash
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Nicky Wybouw
- Terrestrial Ecology Unit, Department of Biology, Ghent University, Ghent, 9000, Belgium
| | - Wannes Dermauw
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Plant Sciences Unit, Merelbeke, 9820, Belgium; Department of Plants and Crops, Ghent University, Ghent, 9000, Belgium
| | - Linda S Shimizu
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | | | - Thomas M Makris
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA; Department of Molecular and Structural Biochemistry, NC State University, Raleigh, NC, 27607, USA
| | - Vojislava Grbic
- Department of Biology, Western University, London, Ontario, N6A 5B7, Canada
| | - Miodrag Grbic
- Department of Biology, Western University, London, Ontario, N6A 5B7, Canada; University of La Rioja, Logrono, Spain
| | - Maksymilian Chruszcz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA.
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10
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Gene regulation network analyses of pistil development in papaya. BMC Genomics 2022; 23:8. [PMID: 34983382 PMCID: PMC8729085 DOI: 10.1186/s12864-021-08197-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 11/15/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The pistil is an essential part of flowers that functions in the differentiation of the sexes and reproduction in plants. The stigma on the pistil can accept pollen to allow fertilization and seed development. Papaya (Carica papaya L.) is a dioecious plant, where female flowers exhibit normal pistil, while the male flowers exhibit aborted pistil at a late stage of pistil development. RESULTS The developmental stages of papaya pistil were analyzed after first dividing it into slices representing the primordium stage 1 (S1), the pre-meiotic stages S2, post-meiotic stage S3, and the mitotic stage S4. The SS scoring algorithm analysis of genes preferentially expressed at different stages revealed differentially expressed genes between male and female flowers. A transcription factor regulatory network for each stage based on the genes that are differentially expressed between male and female flowers was constructed. Some transcription factors related to pistil development were revealed based on the analysis of regulatory networks such as CpAGL11, CpHEC2, and CpSUPL. Based on the specific expression of genes, constructed a gene regulatory subnetwork with CpAGL11-CpSUPL-CpHEC2 functioning as the core. Analysis of the functionally enriched terms in this network reveals several differentially expressed genes related to auxin/ brassinosteroid signal transduction in the plant hormone signal transduction pathway. At the same time, significant differences in the expression of auxin and brassinosteroid synthesis-related genes between male and female flowers at different developmental stages were detected. CONCLUSIONS The pistil abortion of papaya might be caused by the lack of expression or decreased expression of some transcription factors and hormone-related genes, affecting hormone signal transduction or hormone biosynthesis. Analysis of aborted and normally developing pistil in papaya provided new insights into the molecular mechanism of pistil development and sex differentiation in dioecious papaya.
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11
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van der Woude L, Piotrowski M, Klaasse G, Paulus JK, Krahn D, Ninck S, Kaschani F, Kaiser M, Novák O, Ljung K, Bulder S, van Verk M, Snoek BL, Fiers M, Martin NI, van der Hoorn RAL, Robert S, Smeekens S, van Zanten M. The chemical compound 'Heatin' stimulates hypocotyl elongation and interferes with the Arabidopsis NIT1-subfamily of nitrilases. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1523-1540. [PMID: 33768644 PMCID: PMC8360157 DOI: 10.1111/tpj.15250] [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: 01/06/2021] [Accepted: 03/22/2021] [Indexed: 05/17/2023]
Abstract
Temperature passively affects biological processes involved in plant growth. Therefore, it is challenging to study the dedicated temperature signalling pathways that orchestrate thermomorphogenesis, a suite of elongation growth-based adaptations that enhance leaf-cooling capacity. We screened a chemical library for compounds that restored hypocotyl elongation in the pif4-2-deficient mutant background at warm temperature conditions in Arabidopsis thaliana to identify modulators of thermomorphogenesis. The small aromatic compound 'Heatin', containing 1-iminomethyl-2-naphthol as a pharmacophore, was selected as an enhancer of elongation growth. We show that ARABIDOPSIS ALDEHYDE OXIDASES redundantly contribute to Heatin-mediated hypocotyl elongation. Following a chemical proteomics approach, the members of the NITRILASE1-subfamily of auxin biosynthesis enzymes were identified among the molecular targets of Heatin. Our data reveal that nitrilases are involved in promotion of hypocotyl elongation in response to high temperature and Heatin-mediated hypocotyl elongation requires the NITRILASE1-subfamily members, NIT1 and NIT2. Heatin inhibits NIT1-subfamily enzymatic activity in vitro and the application of Heatin accordingly results in the accumulation of NIT1-subfamily substrate indole-3-acetonitrile in vivo. However, levels of the NIT1-subfamily product, bioactive auxin (indole-3-acetic acid), were also significantly increased. It is likely that the stimulation of hypocotyl elongation by Heatin might be independent of its observed interaction with NITRILASE1-subfamily members. However, nitrilases may contribute to the Heatin response by stimulating indole-3-acetic acid biosynthesis in an indirect way. Heatin and its functional analogues present novel chemical entities for studying auxin biology.
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Affiliation(s)
- Lennard van der Woude
- Molecular Plant PhysiologyInstitute of Environmental BiologyUtrecht UniversityPadualaan 8Utrecht3584 CHthe Netherlands
| | - Markus Piotrowski
- Department of Molecular Genetics and Physiology of PlantsFaculty of Biology and BiotechnologyUniversitätsstraße 150Bochum44801Germany
| | - Gruson Klaasse
- Department of Chemical Biology & Drug DiscoveryUtrecht Institute for Pharmaceutical SciencesUniversity UtrechtUniversiteitsweg 99Utrecht3584 CGthe Netherlands
| | - Judith K. Paulus
- Plant Chemetics LaboratoryDepartment of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Daniel Krahn
- Plant Chemetics LaboratoryDepartment of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Sabrina Ninck
- Chemische BiologieZentrum für Medizinische BiotechnologieFakultät für BiologieUniversität Duisburg‐EssenUniversitätsstr. 2Essen45117Germany
| | - Farnusch Kaschani
- Chemische BiologieZentrum für Medizinische BiotechnologieFakultät für BiologieUniversität Duisburg‐EssenUniversitätsstr. 2Essen45117Germany
| | - Markus Kaiser
- Chemische BiologieZentrum für Medizinische BiotechnologieFakultät für BiologieUniversität Duisburg‐EssenUniversitätsstr. 2Essen45117Germany
| | - Ondřej Novák
- Umeå Plant Science CentreDepartment of Forest Genetics and Plant PhysiologySwedish University of Agricultural SciencesUmeaSE‐901 83Sweden
- Laboratory of Growth RegulatorsThe Czech Academy of Sciences & Faculty of ScienceInstitute of Experimental BotanyPalacký UniversityŠlechtitelů 27Olomouc78371Czech Republic
| | - Karin Ljung
- Umeå Plant Science CentreDepartment of Forest Genetics and Plant PhysiologySwedish University of Agricultural SciencesUmeaSE‐901 83Sweden
| | - Suzanne Bulder
- Bejo Zaden B.V.Trambaan 1Warmenhuizen1749 CZthe Netherlands
| | - Marcel van Verk
- Plant‐Microbe InteractionsInstitute of Environmental BiologyUtrecht UniversityPadualaan 8Utrecht3584 CHthe Netherlands
- KeygeneAgro Business Park 90Wageningen6708 PWthe Netherlands
- Theoretical Biology and BioinformaticsInstitute of Biodynamics and BiocomplexityUtrecht UniversityPadualaan 8Utrecht3584 CHthe Netherlands
| | - Basten L. Snoek
- Theoretical Biology and BioinformaticsInstitute of Biodynamics and BiocomplexityUtrecht UniversityPadualaan 8Utrecht3584 CHthe Netherlands
| | - Martijn Fiers
- BioscienceWageningen University and ResearchDroevendaalsesteeg 1Wageningen6708 PBthe Netherlands
| | - Nathaniel I. Martin
- Department of Chemical Biology & Drug DiscoveryUtrecht Institute for Pharmaceutical SciencesUniversity UtrechtUniversiteitsweg 99Utrecht3584 CGthe Netherlands
- Biological Chemistry GroupSylvius LaboratoriesInstitute of Biology LeidenLeiden UniversitySylviusweg 72Leiden2333 BEthe Netherlands
| | - Renier A. L. van der Hoorn
- Plant Chemetics LaboratoryDepartment of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Stéphanie Robert
- Umeå Plant Science CentreDepartment of Forest Genetics and Plant PhysiologySwedish University of Agricultural SciencesUmeaSE‐901 83Sweden
| | - Sjef Smeekens
- Molecular Plant PhysiologyInstitute of Environmental BiologyUtrecht UniversityPadualaan 8Utrecht3584 CHthe Netherlands
| | - Martijn van Zanten
- Molecular Plant PhysiologyInstitute of Environmental BiologyUtrecht UniversityPadualaan 8Utrecht3584 CHthe Netherlands
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Arenas-Alfonseca L, Gotor C, Romero LC, García I. Mutation in Arabidopsis β-cyanoalanine synthase overcomes NADPH oxidase action in response to pathogens. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4535-4547. [PMID: 33770168 DOI: 10.1093/jxb/erab137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
Plant responses to pathogens comprise a complex process, implying a plethora of signals and reactions. Among them, endogenous production of hydrogen cyanide (HCN) has been shown to induce resistance in Arabidopsis to the hemibiotrophic bacterium Pseudomonas syringae pv. tomato (Pst) DC3000. β-cyanoalanine synthase (CAS-C1) is responsible for the detoxification of HCN in Arabidopsis mitochondria. Here, we show that green fluorescent protein-tagged CAS-C1 is transiently reduced in leaves infected with an avirulent strain of Pst during early interactions and increased in leaves infected with a virulent strain of Pst, supporting previous transcriptional data. Genetic crosses show that mutation in CAS-C1 in Arabidopsis resembles the action of the NADPH oxidase RbohD independently of reactive oxygen species production and that the accumulation of salicylic acid is required for HCN-stimulated resistance to Pst. Finally, we show that the cas-c1 mutation acts on the salicylic acid-dependent response to pathogens by mechanisms other than protein ubiquitination or the increase of monomerization and entry to the nucleus of NPR1, the central regulator of the salicylic acid-mediated response. Considering these results, we propose new mechanisms for modulation of the immune response by HCN.
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Affiliation(s)
- Lucía Arenas-Alfonseca
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
| | - Cecilia Gotor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
| | - Luis C Romero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
| | - Irene García
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
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Casanova-Sáez R, Mateo-Bonmatí E, Ljung K. Auxin Metabolism in Plants. Cold Spring Harb Perspect Biol 2021; 13:cshperspect.a039867. [PMID: 33431579 PMCID: PMC7919392 DOI: 10.1101/cshperspect.a039867] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The major natural auxin in plants, indole-3-acetic acid (IAA), orchestrates a plethora of developmental responses that largely depend on the formation of auxin concentration gradients within plant tissues. Together with inter- and intracellular transport, IAA metabolism-which comprises biosynthesis, conjugation, and degradation-modulates auxin gradients and is therefore critical for plant growth. It is now very well established that IAA is mainly produced from Trp and that the IPyA pathway is a major and universally conserved biosynthetic route in plants, while other redundant pathways operate in parallel. Recent findings have shown that metabolic inactivation of IAA is also redundantly performed by oxidation and conjugation processes. An exquisite spatiotemporal expression of the genes for auxin synthesis and inactivation have been shown to drive several plant developmental processes. Moreover, a group of transcription factors and epigenetic regulators controlling the expression of auxin metabolic genes have been identified in past years, which are illuminating the road to understanding the molecular mechanisms behind the coordinated responses of local auxin metabolism to specific cues. Besides transcriptional regulation, subcellular compartmentalization of the IAA metabolism and posttranslational modifications of the metabolic enzymes are emerging as important contributors to IAA homeostasis. In this review, we summarize the current knowledge on (1) the pathways for IAA biosynthesis and inactivation in plants, (2) the influence of spatiotemporally regulated IAA metabolism on auxin-mediated responses, and (3) the regulatory mechanisms that modulate IAA levels in response to external and internal cues during plant development.
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Affiliation(s)
| | | | - Karin Ljung
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
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Plant Nitrilase Homologues in Fungi: Phylogenetic and Functional Analysis with Focus on Nitrilases in Trametes versicolor and Agaricus bisporus. Molecules 2020; 25:molecules25173861. [PMID: 32854275 PMCID: PMC7503981 DOI: 10.3390/molecules25173861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/15/2020] [Accepted: 08/16/2020] [Indexed: 11/17/2022] Open
Abstract
Fungi contain many plant-nitrilase (NLase) homologues according to database searches. In this study, enzymes NitTv1 from Trametes versicolor and NitAb from Agaricus bisporus were purified and characterized as the representatives of this type of fungal NLase. Both enzymes were slightly more similar to NIT4 type than to NIT1/NIT2/NIT3 type of plant NLases in terms of their amino acid sequences. Expression of the synthetic genes in Escherichia coli Origami B (DE3) was induced with 0.02 mM isopropyl β-D-1-thiogalactopyranoside at 20 °C. Purification of NitTv1 and NitAb by cobalt affinity chromatography gave ca. 6.6 mg and 9.6 mg of protein per 100 mL of culture medium, respectively. Their activities were determined with 25 mM of nitriles in 50 mM Tris/HCl buffer, pH 8.0, at 30 °C. NitTv1 and NitAb transformed β-cyano-L-alanine (β-CA) with the highest specific activities (ca. 132 and 40 U mg−1, respectively) similar to plant NLase NIT4. β-CA was transformed into Asn and Asp as in NIT4 but at lower Asn:Asp ratios. The fungal NLases also exhibited significant activities for (aryl)aliphatic nitriles such as 3-phenylpropionitrile, cinnamonitrile and fumaronitrile (substrates of NLase NIT1). NitTv1 was more stable than NitAb (at pH 5–9 vs. pH 5–7). These NLases may participate in plant–fungus interactions by detoxifying plant nitriles and/or producing plant hormones. Their homology models elucidated the molecular interactions with various nitriles in their active sites.
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15
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Egelkamp R, Friedrich I, Hertel R, Daniel R. From sequence to function: a new workflow for nitrilase identification. Appl Microbiol Biotechnol 2020; 104:4957-4970. [PMID: 32291488 PMCID: PMC7228900 DOI: 10.1007/s00253-020-10544-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 02/28/2020] [Accepted: 03/11/2020] [Indexed: 11/16/2022]
Abstract
Abstract Nitrilases are industrially important biocatalysts due to their ability to degrade nitriles to carboxylic acids and ammonia. In this study, a workflow for simple and fast recovery of nitrilase candidates from metagenomes is presented. For identification of active enzymes, a NADH-coupled high-throughput assay was established. Purification of enzymes could be omitted as the assay is based on crude extract containing the expressed putative nitrilases. In addition, long incubation times were avoided by combining nitrile and NADH conversion in a single reaction. This allowed the direct measurement of nitrile degradation and provided not only insights into substrate spectrum and specificity but also in degradation efficiency. The novel assay was used for investigation of candidate nitrilase-encoding genes. Seventy putative nitrilase-encoding gene and the corresponding deduced protein sequences identified during sequence-based screens of metagenomes derived from nitrile-treated microbial communities were analyzed. Subsequently, the assay was applied to 13 selected candidate genes and proteins. Six of the generated corresponding Escherichia coli clones produced nitrilases that showed activity and one unusual nitrilase was purified and analyzed. The activity of the novel arylacetonitrilase Nit09 exhibited a broad pH range and a high long-term stability. The enzyme showed high activity for arylacetonitriles with a KM of 1.29 mM and a Vmax of 13.85 U/mg protein for phenylacetonitrile. In conclusion, we provided a setup for simple and rapid analysis of putative nitrilase-encoding genes from sequence to function. The suitability was demonstrated by identification, isolation, and characterization of the arylacetonitrilase. Key points • A simple and fast high-throughput nitrilase screening was developed. • A set of putative nitrilases was successfully screened with the assay. • A novel arylacetonitrilase was identified, purified, and characterized in detail. Electronic supplementary material The online version of this article (10.1007/s00253-020-10544-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard Egelkamp
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Ines Friedrich
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Robert Hertel
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Rolf Daniel
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany.
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16
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Upscale production of (R)-mandelic acid with a stereospecific nitrilase in an aqueous system. Bioprocess Biosyst Eng 2020; 43:1299-1307. [DOI: 10.1007/s00449-020-02326-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/06/2020] [Indexed: 12/27/2022]
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17
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Blažević I, Montaut S, Burčul F, Olsen CE, Burow M, Rollin P, Agerbirk N. Glucosinolate structural diversity, identification, chemical synthesis and metabolism in plants. PHYTOCHEMISTRY 2020; 169:112100. [PMID: 31771793 DOI: 10.1016/j.phytochem.2019.112100] [Citation(s) in RCA: 237] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 07/04/2019] [Accepted: 08/18/2019] [Indexed: 05/05/2023]
Abstract
The glucosinolates (GSLs) is a well-defined group of plant metabolites characterized by having an S-β-d-glucopyrano unit anomerically connected to an O-sulfated (Z)-thiohydroximate function. After enzymatic hydrolysis, the sulfated aglucone can undergo rearrangement to an isothiocyanate, or form a nitrile or other products. The number of GSLs known from plants, satisfactorily characterized by modern spectroscopic methods (NMR and MS) by mid-2018, is 88. In addition, a group of partially characterized structures with highly variable evidence counts for approximately a further 49. This means that the total number of characterized GSLs from plants is somewhere between 88 and 137. The diversity of GSLs in plants is critically reviewed here, resulting in significant discrepancies with previous reviews. In general, the well-characterized GSLs show resemblance to C-skeletons of the amino acids Ala, Val, Leu, Trp, Ile, Phe/Tyr and Met, or to homologs of Ile, Phe/Tyr or Met. Insufficiently characterized, still hypothetic GSLs include straight-chain alkyl GSLs and chain-elongated GSLs derived from Leu. Additional reports (since 2011) of insufficiently characterized GSLs are reviewed. Usually the crucial missing information is correctly interpreted NMR, which is the most effective tool for GSL identification. Hence, modern use of NMR for GSL identification is also reviewed and exemplified. Apart from isolation, GSLs may be obtained by organic synthesis, allowing isotopically labeled GSLs and any kind of side chain. Enzymatic turnover of GSLs in plants depends on a considerable number of enzymes and other protein factors and furthermore depends on GSL structure. Identification of GSLs must be presented transparently and live up to standard requirements in natural product chemistry. Unfortunately, many recent reports fail in these respects, including reports based on chromatography hyphenated to MS. In particular, the possibility of isomers and isobaric structures is frequently ignored. Recent reports are re-evaluated and interpreted as evidence of the existence of "isoGSLs", i.e. non-GSL isomers of GSLs in plants. For GSL analysis, also with MS-detection, we stress the importance of using authentic standards.
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Affiliation(s)
- Ivica Blažević
- Department of Organic Chemistry, Faculty of Chemistry and Technology, University of Split, Ruđera Boškovića 35, 21000, Split, Croatia.
| | - Sabine Montaut
- Department of Chemistry and Biochemistry, Biomolecular Sciences Programme, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
| | - Franko Burčul
- Department of Analytical Chemistry, Faculty of Chemistry and Technology, University of Split, Ruđera Boškovića 35, 21000, Split, Croatia
| | - Carl Erik Olsen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Meike Burow
- DynaMo Center and Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Patrick Rollin
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans et CNRS, UMR 7311, BP 6759, F-45067, Orléans Cedex 2, France
| | - Niels Agerbirk
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
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A comparative multivariate analysis of nitrilase enzymes: An ensemble based computational approach. Comput Biol Chem 2019; 83:107095. [DOI: 10.1016/j.compbiolchem.2019.107095] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 06/20/2019] [Accepted: 07/11/2019] [Indexed: 12/20/2022]
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19
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Paul B, Maji M, Kundu S. Atom-Economical and Tandem Conversion of Nitriles to N-Methylated Amides Using Methanol and Water. ACS Catal 2019. [DOI: 10.1021/acscatal.9b03916] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Bhaskar Paul
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
| | - Milan Maji
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
| | - Sabuj Kundu
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
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20
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Mozuraitis R, Murtazina R, Zurita J, Pei Y, Ilag L, Wiklund C, Karlson AKB. Anti-aphrodisiac pheromone, a renewable signal in adult butterflies. Sci Rep 2019; 9:14262. [PMID: 31582781 PMCID: PMC6776535 DOI: 10.1038/s41598-019-50838-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 09/09/2019] [Indexed: 11/09/2022] Open
Abstract
The male butterfly Pieris napi produces the anti-aphrodisiac pheromone methyl salicylate (MeS) and transfers it to the female during mating. After mating she releases MeS, when courted by conspecific males, which decreases her attractiveness and the duration of male harassment, thus increasing her time available for egg-laying. In previous studies we have shown that males produced MeS from the amino acid L-phenylalanine (L-Phe) acquired during larval stage. In this study we show that adult males of P. napi can utilize L-Phe and aromatic flower volatiles as building blocks for production of anti-aphrodisiac pheromone and transfer it to females during mating. We demonstrate this by feeding butterflies with stable isotope labelled molecules mixed in sugar solutions, and, to mimic the natural conditions, we fed male butterflies with floral nectar of Bunias orientalis plants treated with labelled L-Phe. The volatiles from butterflies and plants were collected and identified by solid phase micro extraction, gas chromatography and mass spectrometry techniques. Since P. napi is polygamous, males would gain from restoring the titre of MeS after mating and the use of aromatic precursors for production of MeS could be considered as an advantageous trait which could enable butterflies to relocate L-Phe for other needs.
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Affiliation(s)
- Raimondas Mozuraitis
- Department of Zoology, Stockholm University, SE-10691, Stockholm, Sweden. .,Laboratory of Chemical and Behavioural Ecology, Institute of Ecology, Nature Research Centre, Akademijos 2, LT-08412, Vilnius, Lithuania.
| | - Rushana Murtazina
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, KTH, SE-100 44, Stockholm, Sweden
| | - Javier Zurita
- Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-10691, Stockholm, Sweden
| | - Yuxin Pei
- Northwest A&F University, Department of Applied Chemistry, Yangling, Shaanxi, 712100, People's Republic of China
| | - Leopold Ilag
- Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-10691, Stockholm, Sweden
| | - Christer Wiklund
- Department of Zoology, Stockholm University, SE-10691, Stockholm, Sweden
| | - Anna Karin Borg Karlson
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, KTH, SE-100 44, Stockholm, Sweden.,Division of Organic Chemistry, Institute of Technology, Tartu University, Tartu, 50411, Estonia
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Mulelu AE, Kirykowicz AM, Woodward JD. Cryo-EM and directed evolution reveal how Arabidopsis nitrilase specificity is influenced by its quaternary structure. Commun Biol 2019; 2:260. [PMID: 31341959 PMCID: PMC6637149 DOI: 10.1038/s42003-019-0505-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 06/13/2019] [Indexed: 01/17/2023] Open
Abstract
Nitrilases are helical enzymes that convert nitriles to acids and/or amides. All plants have a nitrilase 4 homolog specific for ß-cyanoalanine, while in some plants neofunctionalization has produced nitrilases with altered specificity. Plant nitrilase substrate size and specificity correlate with helical twist, but molecular details of this relationship are lacking. Here we determine, to our knowledge, the first close-to-atomic resolution (3.4 Å) cryo-EM structure of an active helical nitrilase, the nitrilase 4 from Arabidopsis thaliana. We apply site-saturation mutagenesis directed evolution to three residues (R95, S224, and L169) and generate a mutant with an altered helical twist that accepts substrates not catalyzed by known plant nitrilases. We reveal that a loop between α2 and α3 limits the length of the binding pocket and propose that it shifts position as a function of helical twist. These insights will allow us to start designing nitrilases for chemoenzymatic synthesis.
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Affiliation(s)
- Andani E. Mulelu
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925 South Africa
- Structural Biology Research Unit, University of Cape Town, Cape Town, 7925 South Africa
| | - Angela M. Kirykowicz
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925 South Africa
- Structural Biology Research Unit, University of Cape Town, Cape Town, 7925 South Africa
| | - Jeremy D. Woodward
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925 South Africa
- Structural Biology Research Unit, University of Cape Town, Cape Town, 7925 South Africa
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Chhiba-Govindjee VP, van der Westhuyzen CW, Bode ML, Brady D. Bacterial nitrilases and their regulation. Appl Microbiol Biotechnol 2019; 103:4679-4692. [DOI: 10.1007/s00253-019-09776-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 12/25/2022]
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Plant nitrilase: a new job for an old enzyme. Biochem J 2019; 476:1105-1107. [PMID: 30971459 DOI: 10.1042/bcj20190060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 03/26/2019] [Accepted: 03/26/2019] [Indexed: 11/17/2022]
Abstract
Nitrilases are versatile enzymes that hydrolyze nitriles to carboxylic acids and ammonia, but many members of this family lack defined biological functions. In plants, nitrilases have been associated with detoxification of cyanide-containing compounds and auxin biosynthesis; however, recent work suggests that the chemical versatility of these proteins contributes to metabolite repair. In this issue of the Biochemical Journal, Niehaus et al. demonstrate that the Nit1 nitrilase from Arabidopsis thaliana functions as a metabolite repair enzyme that removes deaminated glutathione from the cytoplasm and plastids.
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Lauritano C, De Luca D, Amoroso M, Benfatto S, Maestri S, Racioppi C, Esposito F, Ianora A. New molecular insights on the response of the green alga Tetraselmis suecica to nitrogen starvation. Sci Rep 2019; 9:3336. [PMID: 30833632 PMCID: PMC6399242 DOI: 10.1038/s41598-019-39860-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 02/01/2019] [Indexed: 12/20/2022] Open
Abstract
Microalgae are currently considered one of the most promising resources for biofuel production, aquaculture feedstock and new pharmaceuticals. Among them, green algae of the genus Tetraselmis are extensively studied for their lipid accumulation in nutrient-starvation conditions. In this paper, we present the full-transcriptome of Tetraselmis suecica and differential expression analysis between nitrogen-starved and -repleted conditions (at stationary phase) focusing not only on lipid metabolism but giving new insights on nutrient starvation responses. Transcripts involved in signal transduction pathways, stress and antioxidant responses and solute transport were strongly up-regulated when T. suecica was cultured under nitrogen starvation. On the contrary, transcripts involved in amino acid synthesis, degradation of sugars, secondary metabolite synthesis, as well as photosynthetic activity were down-regulated under the same conditions. Among differentially expressed transcripts, a polyketide synthase and three lipoxygenases (involved in the synthesis of secondary metabolites with antipredator, anticancer and anti-infective activities) were identified, suggesting the potential synthesis of bioactive compounds by this microalga. In addition, the transcript for a putative nitrilase, enzyme used in nitrile bioremediation, is here reported for the first time for T. suecica. These findings give new insights on T. suecica responses to nutrient starvation and on possible biotechnological applications for green algae.
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Affiliation(s)
- Chiara Lauritano
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| | - Daniele De Luca
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Mariano Amoroso
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Salvatore Benfatto
- Università degli Studi di Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Simone Maestri
- Università degli Studi di Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Claudia Racioppi
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.,Center for Developmental Genetics, Department of Biology, College of Arts and Science, New York University, New York, USA
| | - Francesco Esposito
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Adrianna Ianora
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
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Martínková L. Nitrile metabolism in fungi: A review of its key enzymes nitrilases with focus on their biotechnological impact. FUNGAL BIOL REV 2019. [DOI: 10.1016/j.fbr.2018.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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26
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Jeschke V, Weber K, Moore SS, Burow M. Coordination of Glucosinolate Biosynthesis and Turnover Under Different Nutrient Conditions. FRONTIERS IN PLANT SCIENCE 2019; 10:1560. [PMID: 31867028 PMCID: PMC6909823 DOI: 10.3389/fpls.2019.01560] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/07/2019] [Indexed: 05/19/2023]
Abstract
Dynamically changing environmental conditions promote a complex regulation of plant metabolism and balanced resource investments to development and defense. Plants of the Brassicales order constitutively allocate carbon, nitrogen, and sulfur to synthesize glucosinolates as their primary defense metabolites. Previous findings support a model in which steady-state levels of glucosinolates in intact tissues are determined by biosynthesis and turnover through a yet uncharacterized turnover pathway. To investigate glucosinolate turnover in the absence of tissue damage, we quantified exogenously applied allyl glucosinolate and endogenous glucosinolates under different nutrient conditions. Our data shows that, in seedlings of Arabidopsis thaliana accession Columbia-0, glucosinolate biosynthesis and turnover are coordinated according to nutrient availability. Whereas exogenous carbon sources had general quantitative effects on glucosinolate accumulation, sulfur or nitrogen limitation resulted in distinct changes in glucosinolate profiles, indicating that these macronutrients provide different regulatory inputs. Raphanusamic acid, a breakdown product that can potentially be formed from all glucosinolate structures appears not to reflect in planta turnover rates, but instead correlates with increased accumulation of endogenous glucosinolates. Thus, raphanusamic acid could represent a metabolic checkpoint that allows glucosinolate-producing plants to measure the flux through the biosynthetic and/or turnover pathways and thereby to dynamically adjust glucosinolate accumulation in response to internal and external signals.
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27
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Woodward JD, Trompetter I, Sewell BT, Piotrowski M. Substrate specificity of plant nitrilase complexes is affected by their helical twist. Commun Biol 2018; 1:186. [PMID: 30417123 PMCID: PMC6214922 DOI: 10.1038/s42003-018-0186-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 10/01/2018] [Indexed: 01/09/2023] Open
Abstract
Nitrilases are oligomeric, helix-forming enzymes from plants, fungi and bacteria that are involved in the metabolism of various natural and artificial nitriles. These biotechnologically important enzymes are often specific for certain substrates, but directed attempts at modifying their substrate specificities by exchanging binding pocket residues have been largely unsuccessful. Thus, the basis for their selectivity is still unknown. Here we show, based on work with two highly similar nitrilases from the plant Capsella rubella, that modifying nitrilase helical twist, either by exchanging an interface residue or by imposing a different twist, without altering any binding pocket residues, changes substrate preference. We reveal that helical twist and substrate size correlate and when binding pocket residues are exchanged between two nitrilases that show the same twist but different specificities, their specificities change. Based on these findings we propose that helical twist influences the overall size of the binding pocket.
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Affiliation(s)
- Jeremy D Woodward
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925, South Africa.,Department of Molecular Genetics and Physiology of Plants, Ruhr-Universität Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Inga Trompetter
- Department of Molecular Genetics and Physiology of Plants, Ruhr-Universität Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - B Trevor Sewell
- Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925, South Africa
| | - Markus Piotrowski
- Department of Molecular Genetics and Physiology of Plants, Ruhr-Universität Bochum, Universitätsstr. 150, 44801, Bochum, Germany.
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28
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Günther J, Irmisch S, Lackus ND, Reichelt M, Gershenzon J, Köllner TG. The nitrilase PtNIT1 catabolizes herbivore-induced nitriles in Populus trichocarpa. BMC PLANT BIOLOGY 2018; 18:251. [PMID: 30348089 PMCID: PMC6196558 DOI: 10.1186/s12870-018-1478-z] [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: 01/04/2018] [Accepted: 10/10/2018] [Indexed: 05/19/2023]
Abstract
BACKGROUND Nitrilases are nitrile-converting enzymes commonly found within the plant kingdom that play diverse roles in nitrile detoxification, nitrogen recycling, and phytohormone biosynthesis. Although nitrilases are present in all higher plants, little is known about their function in trees. Upon herbivory, poplars produce considerable amounts of toxic nitriles such as benzyl cyanide, 2-methylbutyronitrile, and 3-methylbutyronitrile. In addition, as byproduct of the ethylene biosynthetic pathway upregulated in many plant species after herbivory, toxic β-cyanoalanine may accumulate in damaged poplar leaves. In this work, we studied the nitrilase gene family in Populus trichocarpa and investigated the potential role of the nitrilase PtNIT1 in the catabolism of herbivore-induced nitriles. RESULTS A BLAST analysis revealed three putative nitrilase genes (PtNIT1, PtNIT2, PtNIT3) in the genome of P. trichocarpa. While PtNIT1 was expressed in poplar leaves and showed increased transcript accumulation after leaf herbivory, PtNIT2 and PtNIT3 appeared not to be expressed in undamaged or herbivore-damaged leaves. Recombinant PtNIT1 produced in Escherichia coli accepted biogenic nitriles such as β-cyanoalanine, benzyl cyanide, and indole-3-acetonitrile as substrates in vitro and converted them into the corresponding acids. In addition to this nitrilase activity, PtNIT1 showed nitrile hydratase activity towards β-cyanoalanine, resulting in the formation of the amino acid asparagine. The kinetic parameters of PtNIT1 suggest that the enzyme utilizes β-cyanoalanine and benzyl cyanide as substrates in vivo. Indeed, β-cyanoalanine and benzyl cyanide were found to accumulate in herbivore-damaged poplar leaves. The upregulation of ethylene biosynthesis genes after leaf herbivory indicates that herbivore-induced β-cyanoalanine accumulation is likely caused by ethylene formation. CONCLUSIONS Our data suggest a role for PtNIT1 in the catabolism of herbivore-induced β-cyanoalanine and benzyl cyanide in poplar leaves.
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Affiliation(s)
- Jan Günther
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany
| | - Sandra Irmisch
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany
- Present Address: Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Nathalie D. Lackus
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany
| | - Michael Reichelt
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany
| | - Jonathan Gershenzon
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany
| | - Tobias G. Köllner
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany
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Urbancsok J, Bones AM, Kissen R. Benzyl Cyanide Leads to Auxin-Like Effects Through the Action of Nitrilases in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2018; 9:1240. [PMID: 30197652 PMCID: PMC6117430 DOI: 10.3389/fpls.2018.01240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/06/2018] [Indexed: 05/19/2023]
Abstract
Plants within the Brassicales order generate glucosinolate hydrolysis products that can exert different biological effects on several organisms. Here, we evaluated the physiological effects of one of these compounds, benzyl cyanide (phenylacetonitrile), when exogenously applied on Arabidopsis thaliana. Treatment with benzyl cyanide led to a dose-dependent reduction of primary root length and total biomass. Further morphological changes like elongated hypocotyls, epinastic cotyledons, and increased formation of adventitious roots resembled a severe auxin-overproducer phenotype. The elevated auxin response was confirmed by histochemical staining and gene expression analysis of auxin-responsive genes. Nitriles are converted by specific enzymes, nitrilases (NIT1-3), to their corresponding carboxylic acids. The nitrilase mutants nit1 and nit2 tolerated benzyl cyanide treatments better than the wild type, with nit2 being less resistant than nit1. A NIT2RNAi line suppressing several nitrilases was resistant to all tested benzyl cyanide concentrations. When exposed to phenylacetic acid (PAA) - the corresponding carboxylic acid of benzyl cyanide - wild type and mutant seedlings were, however, equally susceptible and showed a more severe auxin phenotype than upon cyanide treatment. Here, we demonstrate that the auxin-like effects triggered by benzyl cyanide on Arabidopsis are due to its nitrilase-mediated conversion to the natural auxin PAA.
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Affiliation(s)
| | | | - Ralph Kissen
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
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30
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Arenas-Alfonseca L, Gotor C, Romero LC, García I. ß-Cyanoalanine Synthase Action in Root Hair Elongation is Exerted at Early Steps of the Root Hair Elongation Pathway and is Independent of Direct Cyanide Inactivation of NADPH Oxidase. PLANT & CELL PHYSIOLOGY 2018; 59:1072-1083. [PMID: 29490083 DOI: 10.1093/pcp/pcy047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/22/2018] [Indexed: 05/24/2023]
Abstract
In Arabidopsis thaliana, cyanide is produced concomitantly with ethylene biosynthesis and is mainly detoxified by the ß-cyanoalanine synthase CAS-C1. In roots, CAS-C1 activity is essential to maintain a low level of cyanide for proper root hair development. Root hair elongation relies on polarized cell expansion at the growing tip, and we have observed that CAS-C1 locates in mitochondria and accumulates in root hair tips during root hair elongation, as shown by observing the fluorescence in plants transformed with the translational construct ProC1:CASC1-GFP, containing the complete CAS-C1 gene fused to green fluorescent protein (GFP). Mutants in the SUPERCENTIPEDE (SCN1) gene, that regulate the NADPH oxidase gene ROOT HAIR DEFECTIVE 2 (RHD2)/AtrbohC, are affected at the very early steps of the development of root hair that do not elongate and do not show a preferential localization of the GFP accumulation in the tips of the root hair primordia. Root hairs of mutants in CAS-C1 or RHD2/AtrbohC, whose protein product catalyzes the generation of ROS and the Ca2+ gradient, start to grow out correctly, but they do not elongate. Genetic crosses between the cas-c1 mutant and scn1 or rhd2 mutants were performed, and the detailed phenotypic and molecular characterization of the double mutants demonstrates that scn1 mutation is epistatic to cas-c1 and cas-c1 is epistatic to rhd2 mutation, indicating that CAS-C1 acts in early steps of the root hair development process. Moreover, our results show that the role of CAS-C1 in root hair elongation is independent of H2O2 production and of a direct NADPH oxidase inhibition by cyanide.
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Affiliation(s)
- Lucía Arenas-Alfonseca
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
| | - Cecilia Gotor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
| | - Luis C Romero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
| | - Irene García
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, Sevilla 41092, Spain
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31
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Overproduction and characterization of the first enzyme of a new aldoxime dehydratase family in Bradyrhizobium sp. Int J Biol Macromol 2018; 115:746-753. [PMID: 29698761 DOI: 10.1016/j.ijbiomac.2018.04.103] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/18/2018] [Accepted: 04/19/2018] [Indexed: 11/23/2022]
Abstract
Almost 100 genes within the genus Bradyrhizobium are known to potentially encode aldoxime dehydratases (Oxds), but none of the corresponding proteins have been characterized yet. Aldoximes are natural substances involved in plant defense and auxin synthesis, and Oxds are components of enzymatic cascades enabling bacteria to transform, utilize and detoxify them. The aim of this work was to characterize a representative of the highly conserved Oxds in Bradyrhizobium spp. which include both plant symbionts and members of the soil communities. The selected oxd gene from Bradyrhizobium sp. LTSPM299 was expressed in Escherichia coli, and the corresponding gene product (OxdBr1; GenBank: WP_044589203) was obtained as an N-His6-tagged protein (monomer, 40.7 kDa) with 30-47% identity to Oxds characterized previously. OxdBr1 was most stable at pH ca. 7.0-8.0 and at up to 30 °C. As substrates, the enzyme acted on (aryl)aliphatic aldoximes such as E/Z-phenylacetaldoxime, E/Z-2-phenylpropionaldoxime, E/Z-3-phenylpropionaldoxime, E/Z-indole-3-acetaldoxime, E/Z-propionaldoxime, E/Z-butyraldoxime, E/Z-valeraldoxime and E/Z-isovaleraldoxime. Some of the reaction products of OxdBr1 are substrates of nitrilases occurring in the same genus. Regions upstream of the oxd gene contained genes encoding a putative aliphatic nitrilase and its transcriptional activator, indicating the participation of OxdBr1 in the metabolic route from aldoximes to carboxylic acids.
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32
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Woldesemayat AA, Van Heusden P, Ndimba BK, Christoffels A. An integrated and comparative approach towards identification, characterization and functional annotation of candidate genes for drought tolerance in sorghum (Sorghum bicolor (L.) Moench). BMC Genet 2017; 18:119. [PMID: 29273003 PMCID: PMC5741957 DOI: 10.1186/s12863-017-0584-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 12/06/2017] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Drought is the most disastrous abiotic stress that severely affects agricultural productivity worldwide. Understanding the biological basis of drought-regulated traits, requires identification and an in-depth characterization of genetic determinants using model organisms and high-throughput technologies. However, studies on drought tolerance have generally been limited to traditional candidate gene approach that targets only a single gene in a pathway that is related to a trait. In this study, we used sorghum, one of the model crops that is well adapted to arid regions, to mine genes and define determinants for drought tolerance using drought expression libraries and RNA-seq data. RESULTS We provide an integrated and comparative in silico candidate gene identification, characterization and annotation approach, with an emphasis on genes playing a prominent role in conferring drought tolerance in sorghum. A total of 470 non-redundant functionally annotated drought responsive genes (DRGs) were identified using experimental data from drought responses by employing pairwise sequence similarity searches, pathway and interpro-domain analysis, expression profiling and orthology relation. Comparison of the genomic locations between these genes and sorghum quantitative trait loci (QTLs) showed that 40% of these genes were co-localized with QTLs known for drought tolerance. The genome reannotation conducted using the Program to Assemble Spliced Alignment (PASA), resulted in 9.6% of existing single gene models being updated. In addition, 210 putative novel genes were identified using AUGUSTUS and PASA based analysis on expression dataset. Among these, 50% were single exonic, 69.5% represented drought responsive and 5.7% were complete gene structure models. Analysis of biochemical metabolism revealed 14 metabolic pathways that are related to drought tolerance and also had a strong biological network, among categories of genes involved. Identification of these pathways, signifies the interplay of biochemical reactions that make up the metabolic network, constituting fundamental interface for sorghum defence mechanism against drought stress. CONCLUSIONS This study suggests untapped natural variability in sorghum that could be used for developing drought tolerance. The data presented here, may be regarded as an initial reference point in functional and comparative genomics in the Gramineae family.
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Affiliation(s)
- Adugna Abdi Woldesemayat
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Belleville, 7535, South Africa.
- Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, UNISA Science Campus, Corner of Christiaan De Wet Road and Pioneer Avenue, Johannesburg, Florida, 1710, South Africa.
| | - Peter Van Heusden
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Belleville, 7535, South Africa
| | - Bongani K Ndimba
- Department of Biotechnology, University of the Western Cape, Private Bag X17, Belleville, Cape Town, 7535, South Africa
- Agricultural Research Council, Infruitech-Nietvoorbij, Private Bag X5026, Stellenbosch, 7599, South Africa
| | - Alan Christoffels
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Belleville, 7535, South Africa
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Malka SK, Cheng Y. Possible Interactions between the Biosynthetic Pathways of Indole Glucosinolate and Auxin. FRONTIERS IN PLANT SCIENCE 2017; 8:2131. [PMID: 29312389 PMCID: PMC5735125 DOI: 10.3389/fpls.2017.02131] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/30/2017] [Indexed: 05/21/2023]
Abstract
Glucosinolates (GLS) are a group of plant secondary metabolites mainly found in Cruciferous plants, share a core structure consisting of a β-thioglucose moiety and a sulfonated oxime, but differ by a variable side chain derived from one of the several amino acids. These compounds are hydrolyzed upon cell damage by thioglucosidase (myrosinase), and the resulting degradation products are toxic to many pathogens and herbivores. Human beings use these compounds as flavor compounds, anti-carcinogens, and bio-pesticides. GLS metabolism is complexly linked to auxin homeostasis. Indole GLS contributes to auxin biosynthesis via metabolic intermediates indole-3-acetaldoxime (IAOx) and indole-3-acetonitrile (IAN). IAOx is proposed to be a metabolic branch point for biosynthesis of indole GLS, IAA, and camalexin. Interruption of metabolic channeling of IAOx into indole GLS leads to high-auxin production in GLS mutants. IAN is also produced as a hydrolyzed product of indole GLS and metabolized to IAA by nitrilases. In this review, we will discuss current knowledge on involvement of GLS in auxin homeostasis.
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Affiliation(s)
- Siva K. Malka
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Youfa Cheng
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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Del Cueto J, Ionescu IA, Pičmanová M, Gericke O, Motawia MS, Olsen CE, Campoy JA, Dicenta F, Møller BL, Sánchez-Pérez R. Cyanogenic Glucosides and Derivatives in Almond and Sweet Cherry Flower Buds from Dormancy to Flowering. FRONTIERS IN PLANT SCIENCE 2017; 8:800. [PMID: 28579996 PMCID: PMC5437698 DOI: 10.3389/fpls.2017.00800] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/28/2017] [Indexed: 05/07/2023]
Abstract
Almond and sweet cherry are two economically important species of the Prunus genus. They both produce the cyanogenic glucosides prunasin and amygdalin. As part of a two-component defense system, prunasin and amygdalin release toxic hydrogen cyanide upon cell disruption. In this study, we investigated the potential role within prunasin and amygdalin and some of its derivatives in endodormancy release of these two Prunus species. The content of prunasin and of endogenous prunasin turnover products in the course of flower development was examined in five almond cultivars - differing from very early to extra-late in flowering time - and in one sweet early cherry cultivar. In all cultivars, prunasin began to accumulate in the flower buds shortly after dormancy release and the levels dropped again just before flowering time. In almond and sweet cherry, the turnover of prunasin coincided with increased levels of prunasin amide whereas prunasin anitrile pentoside and β-D-glucose-1-benzoate were abundant in almond and cherry flower buds at certain developmental stages. These findings indicate a role for the turnover of cyanogenic glucosides in controlling flower development in Prunus species.
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Affiliation(s)
- Jorge Del Cueto
- Department of Plant Breeding, CEBAS-CSICMurcia, Spain
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- VILLUM Research Center for Plant Plasticity, University of CopenhagenFrederiksberg, Denmark
| | - Irina A. Ionescu
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- VILLUM Research Center for Plant Plasticity, University of CopenhagenFrederiksberg, Denmark
| | - Martina Pičmanová
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- VILLUM Research Center for Plant Plasticity, University of CopenhagenFrederiksberg, Denmark
| | - Oliver Gericke
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- VILLUM Research Center for Plant Plasticity, University of CopenhagenFrederiksberg, Denmark
| | - Mohammed S. Motawia
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- VILLUM Research Center for Plant Plasticity, University of CopenhagenFrederiksberg, Denmark
| | - Carl E. Olsen
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
| | - José A. Campoy
- UMR 1332 BFP, INRA, University of BordeauxVillenave d’Ornon, France
| | | | - Birger L. Møller
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- VILLUM Research Center for Plant Plasticity, University of CopenhagenFrederiksberg, Denmark
| | - Raquel Sánchez-Pérez
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Denmark
- VILLUM Research Center for Plant Plasticity, University of CopenhagenFrederiksberg, Denmark
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35
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A Cyanide-Induced 3-Cyanoalanine Nitrilase in the Cyanide-Assimilating Bacterium Pseudomonas pseudoalcaligenes Strain CECT 5344. Appl Environ Microbiol 2017; 83:AEM.00089-17. [PMID: 28235872 DOI: 10.1128/aem.00089-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 02/15/2017] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas pseudoalcaligenes CECT 5344 is a bacterium able to assimilate cyanide as a sole nitrogen source. Under this growth condition, a 3-cyanoalanine nitrilase enzymatic activity was induced. This activity was encoded by nit4, one of the four nitrilase genes detected in the genome of this bacterium, and its expression in Escherichia coli enabled the recombinant strain to fully assimilate 3-cyanoalanine. P. pseudoalcaligenes CECT 5344 showed a weak growth level with 3-cyanoalanine as the N source, unless KCN was also added. Moreover, a nit4 knockout mutant of P. pseudoalcaligenes CECT 5344 became severely impaired in its ability to grow with 3-cyanoalanine and cyanide as nitrogen sources. The native enzyme expressed in E. coli was purified up to electrophoretic homogeneity and biochemically characterized. Nit4 seems to be specific for 3-cyanoalanine, and the amount of ammonium derived from the enzymatic activity doubled in the presence of exogenously added asparaginase activity, which demonstrated that the Nit4 enzyme had both 3-cyanoalanine nitrilase and hydratase activities. The nit4 gene is located downstream of the cyanide resistance transcriptional unit containing cio1 genes, whose expression levels are under the positive control of cyanide. Real-time PCR experiments revealed that nit4 expression was also positively regulated by cyanide in both minimal and LB media. These results suggest that this gene cluster including cio1 and nit4 could be involved both in cyanide resistance and in its assimilation by P. pseudoalcaligenes CECT 5344.IMPORTANCE Cyanide is a highly toxic molecule present in some industrial wastes due to its application in several manufacturing processes, such as gold mining and the electroplating industry. The biodegradation of cyanide from contaminated wastes could be an attractive alternative to physicochemical treatment. P. pseudoalcaligenes CECT 5344 is a bacterial strain able to assimilate cyanide under alkaline conditions, thus avoiding its volatilization as HCN. This paper describes and characterizes an enzyme (Nit4) induced by cyanide that is probably involved in cyanide assimilation. The biochemical characterization of Nit4 provides a segment for building a cyanide assimilation pathway in P. pseudoalcaligenes This information could be useful for understanding, and hopefully improving, the mechanisms involved in bacterial cyanide biodegradation and its application in the treatment of cyanide-containing wastes.
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Bioengineering of Nitrilases Towards Its Use as Green Catalyst: Applications and Perspectives. Indian J Microbiol 2017; 57:131-138. [PMID: 28611489 DOI: 10.1007/s12088-017-0645-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/20/2017] [Indexed: 10/19/2022] Open
Abstract
Nitrilases are commercial biocatalysts used for the synthesis of plastics, paints, fibers in the chemical industries, pharmaceutical drugs and herbicides for agricultural uses. Nitrilase hydrolyses the nitriles and dinitriles to their corresponding carboxylic acids and ammonia. They have a broad range of substrate specificities as well as enantio-, regio- and chemo-selective properties which make them useful for biotransformation of nitriles to important compounds because of which they are considered as 'Green Catalysts'. Nitriles are widespread in nature and synthesized as a consequence of anthropogenic and biological activities. These are also present in certain plant species and are known to cause environmental pollution. Biotransformation using native organisms as catalysts tends to be insufficient since the enzyme of interest has very low amount in the total cellular protein, rate of reaction is slow along with the instability of enzymes. Therefore, to overcome these limitations, bioengineering offers an alternative approach to alter the properties of enzymes to enhance the applicability and stability. The present review highlights the aspects of producing the recombinant microorganisms and overexpressing the enzyme of interest for the enhanced stability at high temperatures, immobilization techniques, extremes of pH, organic solvents and hydrolysing dintriles to chiral compounds which may enhance the possibilities for creating specific enzymes for biotransformation.
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Rehman HM, Shah ZH, Nawaz MA, Ahmad MQ, Yang SH, Kho KH, Chung G. RETRACTED ARTICLE: Beta-cyanoalanine synthase pathway as a homeostatic mechanism for cyanide detoxification as well as growth and development in higher plants. PLANTA 2017; 245:235. [PMID: 27744484 DOI: 10.1007/s00425-016-2606-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/09/2016] [Indexed: 06/06/2023]
Affiliation(s)
- Hafiz Mamoon Rehman
- Department of Biotechnology, Chonnam National University, Yeosu, Chonnam, 59626, South Korea
| | - Zahid Hussain Shah
- Department of Arid Land Agriculture, King Abdul-Aziz University, Jeddah, 21577, Saudi Arabia
| | - Muhammad Amjad Nawaz
- Department of Biotechnology, Chonnam National University, Yeosu, Chonnam, 59626, South Korea
| | - Muhammad Qadir Ahmad
- Department of Plant Breeding and Genetics, Bahauddin Zakariya University, Multan, 6000, Pakistan
| | - Seung Hwan Yang
- Department of Biotechnology, Chonnam National University, Yeosu, Chonnam, 59626, South Korea
| | - Kang Hee Kho
- Department of Aquatic Biology, Chonnam National University, Yeosu, Chonnam, 59626, South Korea
| | - Gyuhwa Chung
- Department of Biotechnology, Chonnam National University, Yeosu, Chonnam, 59626, South Korea.
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Lehmann T, Janowitz T, Sánchez-Parra B, Alonso MMP, Trompetter I, Piotrowski M, Pollmann S. Arabidopsis NITRILASE 1 Contributes to the Regulation of Root Growth and Development through Modulation of Auxin Biosynthesis in Seedlings. FRONTIERS IN PLANT SCIENCE 2017. [PMID: 28174581 DOI: 10.3389/fpls.2017.00036.ecollection] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Nitrilases consist of a group of enzymes that catalyze the hydrolysis of organic cyanides. They are found ubiquitously distributed in the plant kingdom. Plant nitrilases are mainly involved in the detoxification of ß-cyanoalanine, a side-product of ethylene biosynthesis. In the model plant Arabidopsis thaliana a second group of Brassicaceae-specific nitrilases (NIT1-3) has been found. This so-called NIT1-subfamily has been associated with the conversion of indole-3-acetonitrile (IAN) into the major plant growth hormone, indole-3-acetic acid (IAA). However, apart of reported functions in defense responses to pathogens and in responses to sulfur depletion, conclusive insight into the general physiological function of the NIT-subfamily nitrilases remains elusive. In this report, we test both the contribution of the indole-3-acetaldoxime (IAOx) pathway to general auxin biosynthesis and the influence of altered nitrilase expression on plant development. Apart of a comprehensive transcriptomics approach to explore the role of the IAOx route in auxin formation, we took a genetic approach to disclose the function of NITRILASE 1 (NIT1) of A. thaliana. We show that NIT1 over-expression (NIT1ox) results in seedlings with shorter primary roots, and an increased number of lateral roots. In addition, NIT1ox plants exhibit drastic changes of both free IAA and IAN levels, which are suggested to be the reason for the observed phenotype. On the other hand, NIT2RNAi knockdown lines, capable of suppressing the expression of all members of the NIT1-subfamily, were generated and characterized to substantiate the above-mentioned findings. Our results demonstrate for the first time that Arabidopsis NIT1 has profound effects on root morphogenesis in early seedling development.
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Affiliation(s)
- Thomas Lehmann
- Lehrstuhl für Pflanzenphysiologie Ruhr-Universität Bochum, Bochum, Germany
| | - Tim Janowitz
- Lehrstuhl für Pflanzenphysiologie Ruhr-Universität Bochum, Bochum, Germany
| | - Beatriz Sánchez-Parra
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Pozuelo de Alarcón, Spain
| | - Marta-Marina Pérez Alonso
- Centro de Biotecnología y Genómica de Plantas Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Pozuelo de Alarcón, Spain
| | - Inga Trompetter
- Lehrstuhl für Pflanzenphysiologie Ruhr-Universität Bochum, Bochum, Germany
| | - Markus Piotrowski
- Lehrstuhl für Pflanzenphysiologie Ruhr-Universität Bochum, Bochum, Germany
| | - Stephan Pollmann
- Lehrstuhl für PflanzenphysiologieRuhr-Universität Bochum, Bochum, Germany; Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Pozuelo de Alarcón, Spain
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Lehmann T, Janowitz T, Sánchez-Parra B, Alonso MMP, Trompetter I, Piotrowski M, Pollmann S. Arabidopsis NITRILASE 1 Contributes to the Regulation of Root Growth and Development through Modulation of Auxin Biosynthesis in Seedlings. FRONTIERS IN PLANT SCIENCE 2017; 8:36. [PMID: 28174581 PMCID: PMC5258727 DOI: 10.3389/fpls.2017.00036] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 01/09/2017] [Indexed: 05/20/2023]
Abstract
Nitrilases consist of a group of enzymes that catalyze the hydrolysis of organic cyanides. They are found ubiquitously distributed in the plant kingdom. Plant nitrilases are mainly involved in the detoxification of ß-cyanoalanine, a side-product of ethylene biosynthesis. In the model plant Arabidopsis thaliana a second group of Brassicaceae-specific nitrilases (NIT1-3) has been found. This so-called NIT1-subfamily has been associated with the conversion of indole-3-acetonitrile (IAN) into the major plant growth hormone, indole-3-acetic acid (IAA). However, apart of reported functions in defense responses to pathogens and in responses to sulfur depletion, conclusive insight into the general physiological function of the NIT-subfamily nitrilases remains elusive. In this report, we test both the contribution of the indole-3-acetaldoxime (IAOx) pathway to general auxin biosynthesis and the influence of altered nitrilase expression on plant development. Apart of a comprehensive transcriptomics approach to explore the role of the IAOx route in auxin formation, we took a genetic approach to disclose the function of NITRILASE 1 (NIT1) of A. thaliana. We show that NIT1 over-expression (NIT1ox) results in seedlings with shorter primary roots, and an increased number of lateral roots. In addition, NIT1ox plants exhibit drastic changes of both free IAA and IAN levels, which are suggested to be the reason for the observed phenotype. On the other hand, NIT2RNAi knockdown lines, capable of suppressing the expression of all members of the NIT1-subfamily, were generated and characterized to substantiate the above-mentioned findings. Our results demonstrate for the first time that Arabidopsis NIT1 has profound effects on root morphogenesis in early seedling development.
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Affiliation(s)
- Thomas Lehmann
- Lehrstuhl für PflanzenphysiologieRuhr-Universität Bochum, Bochum, Germany
| | - Tim Janowitz
- Lehrstuhl für PflanzenphysiologieRuhr-Universität Bochum, Bochum, Germany
| | - Beatriz Sánchez-Parra
- Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Pozuelo de Alarcón, Spain
| | - Marta-Marina Pérez Alonso
- Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Pozuelo de Alarcón, Spain
| | - Inga Trompetter
- Lehrstuhl für PflanzenphysiologieRuhr-Universität Bochum, Bochum, Germany
| | - Markus Piotrowski
- Lehrstuhl für PflanzenphysiologieRuhr-Universität Bochum, Bochum, Germany
| | - Stephan Pollmann
- Lehrstuhl für PflanzenphysiologieRuhr-Universität Bochum, Bochum, Germany
- Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentación (INIA), Pozuelo de Alarcón, Spain
- *Correspondence: Stephan Pollmann
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Machingura M, Salomon E, Jez JM, Ebbs SD. The β-cyanoalanine synthase pathway: beyond cyanide detoxification. PLANT, CELL & ENVIRONMENT 2016; 39:2329-41. [PMID: 27116378 DOI: 10.1111/pce.12755] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 04/04/2016] [Accepted: 04/06/2016] [Indexed: 05/21/2023]
Abstract
Production of cyanide through biological and environmental processes requires the detoxification of this metabolic poison. In the 1960s, discovery of the β-cyanoalanine synthase (β-CAS) pathway in cyanogenic plants provided the first insight on cyanide detoxification in nature. Fifty years of investigations firmly established the protective role of the β-CAS pathway in cyanogenic plants and its role in the removal of cyanide produced from ethylene synthesis in plants, but also revealed the importance of this pathway for plant growth and development and the integration of nitrogen and sulfur metabolism. This review describes the β-CAS pathway, its distribution across and within higher plants, and the diverse biological functions of the pathway in cyanide assimilation, plant growth and development, stress tolerance, regulation of cyanide and sulfide signalling, and nitrogen and sulfur metabolism. The collective roles of the β-CAS pathway highlight its potential evolutionary and ecological importance in plants.
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Affiliation(s)
- Marylou Machingura
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Eitan Salomon
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Joseph M Jez
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Stephen D Ebbs
- Department of Plant Biology and Center for Ecology, Southern Illinois University, Carbondale, IL, 62901, USA.
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Le Deunff E, Lecourt J. Non-specificity of ethylene inhibitors: 'double-edged' tools to find out new targets involved in the root morphogenetic programme. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:353-61. [PMID: 26434926 DOI: 10.1111/plb.12405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 09/24/2015] [Indexed: 05/23/2023]
Abstract
In the last decade, genetic and pharmacological approaches have been used to explore ethylene biosynthesis and perception in order to study the role of ethylene and ethylene/auxin interaction in root architecture development. However, recent findings with pharmacological approaches highlight the non-specificity of commonly used inhibitors. This suggests that caution is required for interpreting these studies and that the use of pharmacological agents is a 'double-edged' tool. On one hand, non-specific effects make interpretation difficult unless other experiments, such as with different mutants or with multiple diversely acting chemicals, are conducted. On the other hand, the non-specificity of inhibitors opens up the possibility of uncovering some ligands or modulators of new receptors such as plant glutamate-like receptors and importance of some metabolic hubs in carbon and nitrogen metabolism such as the pyridoxal phosphate biosynthesis involved in the regulation of the root morphogenetic programme. Identification of such targets is a critical issue to improve the efficiency of absorption of macronutrients in relation to root the morphogenetic programme.
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Affiliation(s)
- E Le Deunff
- Normandie Université, UMR EVA, F-14032, Caen cedex, France
- INRA, UMR 950, Écophysiologie Végétale & Agronomie, Nutritions NCS, INRA F-14032 Caen cedex, France
| | - J Lecourt
- East Malling Research, East Malling, Kent, UK
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Brasileiro ACM, Morgante CV, Araujo ACG, Leal-Bertioli SCM, Silva AK, Martins ACQ, Vinson CC, Santos CMR, Bonfim O, Togawa RC, Saraiva MAP, Bertioli DJ, Guimaraes PM. Transcriptome Profiling of Wild Arachis from Water-Limited Environments Uncovers Drought Tolerance Candidate Genes. PLANT MOLECULAR BIOLOGY REPORTER 2015; 33:1876-1892. [PMID: 26752807 PMCID: PMC4695501 DOI: 10.1007/s11105-015-0882-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Peanut (Arachis hypogaea L.) is an important legume cultivated mostly in drought-prone areas where its productivity can be limited by water scarcity. The development of more drought-tolerant varieties is, therefore, a priority for peanut breeding programs worldwide. In contrast to cultivated peanut, wild relatives have a broader genetic diversity and constitute a rich source of resistance/tolerance alleles to biotic and abiotic stresses. The present study takes advantage of this diversity to identify drought-responsive genes by analyzing the expression profile of two wild species, Arachis duranensis and Arachis magna (AA and BB genomes, respectively), in response to progressive water deficit in soil. Data analysis from leaves and roots of A. duranensis (454 sequencing) and A. magna (suppression subtractive hybridization (SSH)) stressed and control complementary DNA (cDNA) libraries revealed several differentially expressed genes in silico, and 44 of them were selected for further validation by quantitative RT-PCR (qRT-PCR). This allowed the identification of drought-responsive candidate genes, such as Expansin, Nitrilase, NAC, and bZIP transcription factors, displaying significant levels of differential expression during stress imposition in both species. This is the first report on identification of differentially expressed genes under drought stress and recovery in wild Arachis species. The generated transcriptome data, besides being a valuable resource for gene discovery, will allow the characterization of new alleles and development of molecular markers associated with drought responses in peanut. These together constitute important tools for the peanut breeding program and also contribute to a better comprehension of gene modulation in response to water deficit and rehydration.
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Affiliation(s)
- Ana C. M. Brasileiro
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Carolina V. Morgante
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
- />Embrapa Semiárido, Petrolina, PE Brazil
| | - Ana C. G. Araujo
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Soraya C. M. Leal-Bertioli
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Amanda K. Silva
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Andressa C. Q. Martins
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Christina C. Vinson
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Candice M. R. Santos
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
- />CONAB, Brasília, DF Brazil
| | - Orzenil Bonfim
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Roberto C. Togawa
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | - Mario A. P. Saraiva
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
| | | | - Patricia M. Guimaraes
- />Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 02372 Final W5 Norte, Brasília, DF Brazil
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Frisch T, Motawia MS, Olsen CE, Agerbirk N, Møller BL, Bjarnholt N. Diversified glucosinolate metabolism: biosynthesis of hydrogen cyanide and of the hydroxynitrile glucoside alliarinoside in relation to sinigrin metabolism in Alliaria petiolata. FRONTIERS IN PLANT SCIENCE 2015; 6:926. [PMID: 26583022 PMCID: PMC4628127 DOI: 10.3389/fpls.2015.00926] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 10/13/2015] [Indexed: 05/06/2023]
Abstract
Alliaria petiolata (garlic mustard, Brassicaceae) contains the glucosinolate sinigrin as well as alliarinoside, a γ-hydroxynitrile glucoside structurally related to cyanogenic glucosides. Sinigrin may defend this plant against a broad range of enemies, while alliarinoside confers resistance to specialized (glucosinolate-adapted) herbivores. Hydroxynitrile glucosides and glucosinolates are two classes of specialized metabolites, which generally do not occur in the same plant species. Administration of [UL-(14)C]-methionine to excised leaves of A. petiolata showed that both alliarinoside and sinigrin were biosynthesized from methionine. The biosynthesis of alliarinoside was shown not to bifurcate from sinigrin biosynthesis at the oxime level in contrast to the general scheme for hydroxynitrile glucoside biosynthesis. Instead, the aglucon of alliarinoside was formed from metabolism of sinigrin in experiments with crude extracts, suggesting a possible biosynthetic pathway in intact cells. Hence, the alliarinoside pathway may represent a route to hydroxynitrile glucoside biosynthesis resulting from convergent evolution. Metabolite profiling by LC-MS showed no evidence of the presence of cyanogenic glucosides in A. petiolata. However, we detected hydrogen cyanide (HCN) release from sinigrin and added thiocyanate ion and benzyl thiocyanate in A. petiolata indicating an enzymatic pathway from glucosinolates via allyl thiocyanate and indole glucosinolate derived thiocyanate ion to HCN. Alliarinoside biosynthesis and HCN release from glucosinolate-derived metabolites expand the range of glucosinolate-related defenses and can be viewed as a third line of defense, with glucosinolates and thiocyanate forming protein being the first and second lines, respectively.
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Affiliation(s)
- Tina Frisch
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- VILLUM Research Center for Plant Plasticity, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
| | - Mohammed S. Motawia
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- VILLUM Research Center for Plant Plasticity, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- Center for Synthetic Biology “bioSYNergy”, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
| | - Carl E. Olsen
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- VILLUM Research Center for Plant Plasticity, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- Center for Synthetic Biology “bioSYNergy”, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
| | - Niels Agerbirk
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
| | - Birger L. Møller
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- VILLUM Research Center for Plant Plasticity, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- Center for Synthetic Biology “bioSYNergy”, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
| | - Nanna Bjarnholt
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- VILLUM Research Center for Plant Plasticity, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of CopenhagenCopenhagen, Denmark
- *Correspondence: Nanna Bjarnholt
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Glucosinolate-related glucosides in Alliaria petiolata: sources of variation in the plant and different metabolism in an adapted specialist herbivore, Pieris rapae. J Chem Ecol 2014; 40:1063-79. [PMID: 25308480 DOI: 10.1007/s10886-014-0509-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 09/14/2014] [Accepted: 09/19/2014] [Indexed: 10/24/2022]
Abstract
Specialized metabolites in plants influence their interactions with other species, including herbivorous insects, which may adapt to tolerate defensive phytochemicals. The chemical arsenal of Alliaria petiolata (garlic mustard, Brassicaceae) includes the glucosinolate sinigrin and alliarinoside, a hydroxynitrile glucoside with defensive properties to glucosinolate-adapted specialists. To further our understanding of the chemical ecology of A. petiolata, which is spreading invasively in North America, we investigated the metabolite profile and here report a novel natural product, petiolatamide, which is structurally related to sinigrin. In an extensive study of North American populations of A. petiolata, we demonstrate that genetic population differences as well as developmental regulation contribute to variation in the leaf content of petiolatamide, alliarinoside, sinigrin, and a related glycoside. We furthermore demonstrate widely different metabolic fates of these metabolites after ingestion in the glucosinolate-adapted herbivore Pieris rapae, ranging from simple passage over metabolic conversion to sequestration. The differences in metabolic fate were influenced by plant β-glucosidases, insect-mediated degradation, and the specificity of the larval gut transport system mediating sequestration.
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Romero LC, Aroca MÁ, Laureano-Marín AM, Moreno I, García I, Gotor C. Cysteine and cysteine-related signaling pathways in Arabidopsis thaliana. MOLECULAR PLANT 2014; 7:264-76. [PMID: 24285094 DOI: 10.1093/mp/sst168] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Cysteine occupies a central position in plant metabolism because it is a reduced sulfur donor molecule involved in the synthesis of essential biomolecules and defense compounds. Moreover, cysteine per se and its derivative molecules play roles in the redox signaling of processes occurring in various cellular compartments. Cysteine is synthesized during the sulfate assimilation pathway via the incorporation of sulfide to O-acetylserine, catalyzed by O-acetylserine(thiol)lyase (OASTL). Plant cells contain OASTLs in the mitochondria, chloroplasts, and cytosol, resulting in a complex array of isoforms and subcellular cysteine pools. In recent years, significant progress has been made in Arabidopsis, in determining the specific roles of the OASTLs and the metabolites produced by them. Thus, the discovery of novel enzymatic activities of the less-abundant, like DES1 with L-cysteine desulfhydrase activity and SCS with S-sulfocysteine synthase activity, has provided new perspectives on their roles, besides their metabolic functions. Thereby, the research has been demonstrated that cytosolic sulfide and chloroplastic S-sulfocysteine act as signaling molecules regulating autophagy and protecting the photosystems, respectively. In the cytosol, cysteine plays an essential role in plant immunity; in the mitochondria, this molecule plays a central role in the detoxification of cyanide, which is essential for root hair development and plant responses to pathogens.
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Affiliation(s)
- Luis C Romero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, 41092 Sevilla, Spain
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Spaepen S, Bossuyt S, Engelen K, Marchal K, Vanderleyden J. Phenotypical and molecular responses of Arabidopsis thaliana roots as a result of inoculation with the auxin-producing bacterium Azospirillum brasilense. THE NEW PHYTOLOGIST 2014; 201:850-861. [PMID: 24219779 DOI: 10.1111/nph.12590] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 09/24/2013] [Indexed: 05/18/2023]
Abstract
The auxin-producing bacterium Azospirillum brasilense Sp245 can promote the growth of several plant species. The model plant Arabidopsis thaliana was chosen as host plant to gain an insight into the molecular mechanisms that govern this interaction. The determination of differential gene expression in Arabidopsis roots after inoculation with either A. brasilense wild-type or an auxin biosynthesis mutant was achieved by microarray analysis. Arabidopsis thaliana inoculation with A. brasilense wild-type increases the number of lateral roots and root hairs, and elevates the internal auxin concentration in the plant. The A. thaliana root transcriptome undergoes extensive changes on A. brasilense inoculation, and the effects are more pronounced at later time points. The wild-type bacterial strain induces changes in hormone- and defense-related genes, as well as in plant cell wall-related genes. The A. brasilense mutant, however, does not elicit these transcriptional changes to the same extent. There are qualitative and quantitative differences between A. thaliana responses to the wild-type A. brasilense strain and the auxin biosynthesis mutant strain, based on both phenotypic and transcriptomic data. This illustrates the major role played by auxin in the Azospirillum-Arabidopsis interaction, and possibly also in other bacterium-plant interactions.
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Affiliation(s)
- Stijn Spaepen
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium
| | - Stijn Bossuyt
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium
| | - Kristof Engelen
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium
- Fondazione Edmund Mach, Research and Innovation Centre, Via E. Mach, 1, 38010, San Michele all'Adige, Trento, Italy
| | - Kathleen Marchal
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Gent, Belgium
| | - Jos Vanderleyden
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium
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Dam S, Dyrlund TF, Ussatjuk A, Jochimsen B, Nielsen K, Goffard N, Ventosa M, Lorentzen A, Gupta V, Andersen SU, Enghild JJ, Ronson CW, Roepstorff P, Stougaard J. Proteome reference maps of the Lotus japonicus nodule and root. Proteomics 2014; 14:230-40. [PMID: 24293220 DOI: 10.1002/pmic.201300353] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/11/2013] [Accepted: 11/11/2013] [Indexed: 12/29/2022]
Abstract
Legume symbiosis with rhizobia results in the formation of a specialized organ, the root nodule, where atmospheric dinitrogen is reduced to ammonia. In Lotus japonicus (Lotus), several genes involved in nodule development or nodule function have been defined using biochemistry, genetic approaches, and high-throughput transcriptomics. We have employed proteomics to further understand nodule development. Two developmental stages representing nodules prior to nitrogen fixation (white) and mature nitrogen fixing nodules (red) were compared with roots. In addition, the proteome of a spontaneous nodule formation mutant (snf1) was determined. From nodules and roots, 780 and 790 protein spots from 2D gels were identified and approximately 45% of the corresponding unique gene accessions were common. Including a previous proteomics set from Lotus pod and seed, the common gene accessions were decreased to 7%. Interestingly, an indication of more pronounced PTMs in nodules than in roots was determined. Between the two nodule developmental stages, higher levels of pathogen-related 10 proteins, HSPs, and proteins involved in redox processes were found in white nodules, suggesting a higher stress level at this developmental stage. In contrast, protein spots corresponding to nodulins such as leghemoglobin, asparagine synthetase, sucrose synthase, and glutamine synthetase were prevalent in red nodules. The distinct biochemical state of nodules was further highlighted by the conspicuous presence of several nitrilases, ascorbate metabolic enzymes, and putative rhizobial effectors.
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Affiliation(s)
- Svend Dam
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Centre for Carbohydrate Recognition and Signalling, Aarhus University, Aarhus, Denmark
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García I, Gotor C, Romero LC. Beyond toxicity: a regulatory role for mitochondrial cyanide. PLANT SIGNALING & BEHAVIOR 2014; 9:e27612. [PMID: 24398435 PMCID: PMC4091212 DOI: 10.4161/psb.27612] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In non-cyanogenic plants, cyanide is a co-product of ethylene and camalexin biosynthesis. To maintain cyanide at non-toxic levels, Arabidopsis plants express the mitochondrial β-cyanoalanine synthase CYS-C1. CYS-C1 knockout leads to an increased level of cyanide in the roots and leaves and a severe defect in root hair morphogenesis, suggesting that cyanide acts as a signaling factor in root development. During compatible and incompatible plant-bacteria interactions, cyanide accumulation and CYS-C1 gene expression are negatively correlated. Moreover, CYS-C1 mutation increases both plant tolerance to biotrophic pathogens and their susceptibility to necrotrophic fungi, indicating that cyanide could stimulate the salicylic acid-dependent signaling pathway of the plant immune system. We hypothesize that CYS-C1 is essential for maintaining non-toxic concentrations of cyanide in the mitochondria to facilitate cyanide's role in signaling.
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O'Leary B, Preston GM, Sweetlove LJ. Increased β-cyanoalanine nitrilase activity improves cyanide tolerance and assimilation in Arabidopsis. MOLECULAR PLANT 2014; 7:231-243. [PMID: 23825089 DOI: 10.1093/mp/sst110] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Plants naturally produce cyanide (CN) which is maintained at low levels in their cells by a process of rapid assimilation. However, high concentrations of environmental CN associated with activities such as industrial pollution are toxic to plants. There is thus an interest in increasing the CN detoxification capacity of plants as a potential route to phytoremediation. Here, Arabidopsis seedlings overexpressing the Pseudomonas fluorescens β-cyanoalanine nitrilase pinA were compared with wild-type and a β-cyanoalanine nitrilase knockout line (ΔAtnit4) for growth in the presence of exogenous CN. After incubation with CN, +PfpinA seedlings had increased root length, increased fresh weight, and decreased leaf bleaching compared with wild-type, indicating increased CN tolerance. The increased tolerance was achieved without an increase in β-cyanoalanine synthase activity, the other enzyme in the cyanide assimilation pathway, suggesting that nitrilase activity is the limiting factor for cyanide detoxification. Labeling experiments with [¹³C]KCN demonstrated that the altered CN tolerance could be explained by differences in flux from CN to Asn caused by altered β-cyanoalanine nitrilase activity. Metabolite profiling after CN treatment provided new insight into downstream metabolism, revealing onward metabolism of Asn by the photorespiratory nitrogen cycle and accumulation of aromatic amino acids.
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Affiliation(s)
- Brendan O'Leary
- Department of Plant Sciences, University of Oxford, Oxford, UK
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Gleadow RM, Møller BL. Cyanogenic glycosides: synthesis, physiology, and phenotypic plasticity. ANNUAL REVIEW OF PLANT BIOLOGY 2014; 65:155-85. [PMID: 24579992 DOI: 10.1146/annurev-arplant-050213-040027] [Citation(s) in RCA: 234] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Cyanogenic glycosides (CNglcs) are bioactive plant products derived from amino acids. Structurally, these specialized plant compounds are characterized as α-hydroxynitriles (cyanohydrins) that are stabilized by glucosylation. In recent years, improved tools within analytical chemistry have greatly increased the number of known CNglcs by enabling the discovery of less abundant CNglcs formed by additional hydroxylation, glycosylation, and acylation reactions. Cyanogenesis--the release of toxic hydrogen cyanide from endogenous CNglcs--is an effective defense against generalist herbivores but less effective against fungal pathogens. In the course of evolution, CNglcs have acquired additional roles to improve plant plasticity, i.e., establishment, robustness, and viability in response to environmental challenges. CNglc concentration is usually higher in young plants, when nitrogen is in ready supply, or when growth is constrained by nonoptimal growth conditions. Efforts are under way to engineer CNglcs into some crops as a pest control measure, whereas in other crops efforts are directed toward their removal to improve food safety. Given that many food crops are cyanogenic, it is important to understand the molecular mechanisms regulating cyanogenesis so that the impact of future environmental challenges can be anticipated.
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Affiliation(s)
- Roslyn M Gleadow
- School of Biological Sciences, Monash University, 3800 Victoria, Australia;
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