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Sánchez-Pérez R, Neilson EH. The case for sporadic cyanogenic glycoside evolution in plants. CURRENT OPINION IN PLANT BIOLOGY 2024; 81:102608. [PMID: 39089185 DOI: 10.1016/j.pbi.2024.102608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/04/2024] [Accepted: 07/05/2024] [Indexed: 08/03/2024]
Abstract
Cyanogenic glycosides are α-hydroxynitrile glucosides present in approximately 3000 different plant species. Upon tissue disruption, cyanogenic glycosides are hydrolyzed to release toxic hydrogen cyanide as a means of chemical defense. Over 100 different cyanogenic glycosides have been reported, with structural diversity dependent on the precursor amino acid, and subsequent modifications. Cyanogenic glycosides represent a prime example of sporadic metabolite evolution, with the metabolic trait arising multiple times throughout the plant lineage as evidenced by recruitment of different enzyme families for biosynthesis. Here, we review the latest developments within cyanogenic glycoside biosynthesis, and argue possible factors driving sporadic evolution including shared intermediates and crossovers with other metabolic pathways crossovers, and metabolite multifunctionality beyond chemical defense.
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Affiliation(s)
| | - Elizabeth Hj Neilson
- Plant Biochemistry Section, Department of Plant and Environmental Sciences, University of Copenhagen.
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2
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Sun S, Bakkeren G. A bird's-eye view: exploration of the flavin-containing monooxygenase superfamily in common wheat. FRONTIERS IN PLANT SCIENCE 2024; 15:1369299. [PMID: 38681221 PMCID: PMC11046709 DOI: 10.3389/fpls.2024.1369299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 02/19/2024] [Indexed: 05/01/2024]
Abstract
The Flavin Monooxygenase (FMO) gene superfamily in plants is involved in various processes most widely documented for its involvement in auxin biosynthesis, specialized metabolite biosynthesis, and plant microbial defense signaling. The roles of FMOs in defense signaling and disease resistance have recently come into focus as they may present opportunities to increase immune responses in plants including leading to systemic acquired resistance, but are not well characterized. We present a comprehensive catalogue of FMOs found in genomes across vascular plants and explore, in depth, 170 wheat TaFMO genes for sequence architecture, cis-acting regulatory elements, and changes due to Transposable Element insertions. A molecular phylogeny separates TaFMOs into three clades (A, B, and C) for which we further report gene duplication patterns, and differential rates of homoeologue expansion and retention among TaFMO subclades. We discuss Clade B TaFMOs where gene expansion is similarly seen in other cereal genomes. Transcriptome data from various studies point towards involvement of subclade B2 TaFMOs in disease responses against both biotrophic and necrotrophic pathogens, substantiated by promoter element analysis. We hypothesize that certain TaFMOs are responsive to both abiotic and biotic stresses, providing potential targets for enhancing disease resistance, plant yield and other important agronomic traits. Altogether, FMOs in wheat and other crop plants present an untapped resource to be exploited for improving the quality of crops.
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Affiliation(s)
- Sherry Sun
- Department of Botany, The University of British Columbia, Vancouver, BC, Canada
| | - Guus Bakkeren
- Agriculture and Agri-Food Canada, Summerland Research & Development Center, Summerland, BC, Canada
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Müller AT, Nakamura Y, Reichelt M, Luck K, Cosio E, Lackus ND, Gershenzon J, Mithöfer A, Köllner TG. Biosynthesis, herbivore induction, and defensive role of phenylacetaldoxime glucoside. PLANT PHYSIOLOGY 2023; 194:329-346. [PMID: 37584327 PMCID: PMC10756763 DOI: 10.1093/plphys/kiad448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 07/12/2023] [Accepted: 07/16/2023] [Indexed: 08/17/2023]
Abstract
Aldoximes are well-known metabolic precursors for plant defense compounds such as cyanogenic glycosides, glucosinolates, and volatile nitriles. They are also defenses themselves produced in response to herbivory; however, it is unclear whether aldoximes can be stored over a longer term as defense compounds and how plants protect themselves against the potential autotoxic effects of aldoximes. Here, we show that the Neotropical myrmecophyte tococa (Tococa quadrialata, recently renamed Miconia microphysca) accumulates phenylacetaldoxime glucoside (PAOx-Glc) in response to leaf herbivory. Sequence comparison, transcriptomic analysis, and heterologous expression revealed that 2 cytochrome P450 enzymes, CYP79A206 and CYP79A207, and the UDP-glucosyltransferase UGT85A123 are involved in the formation of PAOx-Glc in tococa. Another P450, CYP71E76, was shown to convert PAOx to the volatile defense compound benzyl cyanide. The formation of PAOx-Glc and PAOx in leaves is a very local response to herbivory but does not appear to be regulated by jasmonic acid signaling. In contrast to PAOx, which was only detectable during herbivory, PAOx-Glc levels remained high for at least 3 d after insect feeding. This, together with the fact that gut protein extracts of 3 insect herbivore species exhibited hydrolytic activity toward PAOx-Glc, suggests that the glucoside is a stable storage form of a defense compound that may provide rapid protection against future herbivory. Moreover, the finding that herbivory or pathogen elicitor treatment also led to the accumulation of PAOx-Glc in 3 other phylogenetically distant plant species suggests that the formation and storage of aldoxime glucosides may represent a widespread plant defense response.
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Affiliation(s)
- Andrea T Müller
- Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
- Pontifical Catholic University of Peru, Institute for Nature Earth and Energy (INTE-PUCP), San Miguel 15088, Lima, Peru
| | - Yoko Nakamura
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
- Department of Natural Product Research, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Katrin Luck
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Eric Cosio
- Pontifical Catholic University of Peru, Institute for Nature Earth and Energy (INTE-PUCP), San Miguel 15088, Lima, Peru
| | - Nathalie D Lackus
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Axel Mithöfer
- Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Tobias G Köllner
- Department of Natural Product Research, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
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Nicoll C, Mascotti M. Investigating the biochemical signatures and physiological roles of the FMO family using molecular phylogeny. BBA ADVANCES 2023; 4:100108. [PMID: 38034983 PMCID: PMC10682829 DOI: 10.1016/j.bbadva.2023.100108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 12/02/2023] Open
Abstract
Group B flavin-dependent monooxygenases are employed in swathes of different physiological functions. Despite their collectively large substrate profile, they all harness a flavin-based C4a-(hydro)peroxy intermediate for function. Within this class are the flavin-containing monooxygenases (FMOs), representing an integral component within the secondary metabolism of all living things - xenobiotic detoxification. Their broad substrate profile makes them ideal candidates for detoxifying procedures as they can tackle a range of compounds. Recent studies have illustrated that several FMOs, however, have unique substrate profiles and differing physiological functions that implicate new roles within secondary and primary metabolism. Herein this article, by employing phylogenetic approaches, and inspecting structures of AlphaFold generated models, we have constructed a biochemical blueprint of the FMO family. FMOs are clustered in four distinct groups, with two being predominantly dedicated to xenobiotic detoxification. Furthermore, we observe that differing enzymatic activities are not constricted to a 'golden' set of residues but instead an intricate constellation of primary and secondary sphere residues. We believe that this work delineates the core phylogeny of the Group B monooxygenases and will prove useful for classifying newly sequenced genes and provide directions to future biochemical investigations.
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Affiliation(s)
- C.R. Nicoll
- Department of Biology and Biotechnology Lazzaro Spallanzani, University of Pavia, Via Ferrata 9, 27100, Pavia, Italy
| | - M.L. Mascotti
- Molecular Enzymology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747, AG Groningen, The Netherlands
- IMIBIO-SL CONICET, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejercito de los Andes 950, D5700HHW, San Luis, Argentina
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Florean M, Luck K, Hong B, Nakamura Y, O’Connor SE, Köllner TG. Reinventing metabolic pathways: Independent evolution of benzoxazinoids in flowering plants. Proc Natl Acad Sci U S A 2023; 120:e2307981120. [PMID: 37812727 PMCID: PMC10589660 DOI: 10.1073/pnas.2307981120] [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: 05/12/2023] [Accepted: 08/30/2023] [Indexed: 10/11/2023] Open
Abstract
Benzoxazinoids (BXDs) form a class of indole-derived specialized plant metabolites with broad antimicrobial and antifeedant properties. Unlike most specialized metabolites, which are typically lineage-specific, BXDs occur sporadically in a number of distantly related plant orders. This observation suggests that BXD biosynthesis arose independently numerous times in the plant kingdom. However, although decades of research in the grasses have led to the elucidation of the BXD pathway in the monocots, the biosynthesis of BXDs in eudicots is unknown. Here, we used a metabolomic and transcriptomic-guided approach, in combination with pathway reconstitution in Nicotiana benthamiana, to identify and characterize the BXD biosynthetic pathways from both Aphelandra squarrosa and Lamium galeobdolon, two phylogenetically distant eudicot species. We show that BXD biosynthesis in A. squarrosa and L. galeobdolon utilize a dual-function flavin-containing monooxygenase in place of two distinct cytochrome P450s, as is the case in the grasses. In addition, we identified evolutionarily unrelated cytochrome P450s, a 2-oxoglutarate-dependent dioxygenase, a UDP-glucosyltransferase, and a methyltransferase that were also recruited into these BXD biosynthetic pathways. Our findings constitute the discovery of BXD pathways in eudicots. Moreover, the biosynthetic enzymes of these pathways clearly demonstrate that BXDs independently arose in the plant kingdom at least three times. The heterogeneous pool of identified BXD enzymes represents a remarkable example of metabolic plasticity, in which BXDs are synthesized according to a similar chemical logic, but with an entirely different set of metabolic enzymes.
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Affiliation(s)
- Matilde Florean
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Jena07745, Germany
| | - Katrin Luck
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Jena07745, Germany
| | - Benke Hong
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Jena07745, Germany
| | - Yoko Nakamura
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, Jena07745, Germany
| | - Sarah E. O’Connor
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Jena07745, Germany
| | - Tobias G. Köllner
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Jena07745, Germany
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6
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Shin D, Perez VC, Dickinson GK, Zhao H, Dai R, Tomiczek B, Cho KH, Zhu N, Koh J, Grenning A, Kim J. Altered methionine metabolism impacts phenylpropanoid production and plant development in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:187-200. [PMID: 37366635 DOI: 10.1111/tpj.16370] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/20/2023] [Indexed: 06/28/2023]
Abstract
Phenylpropanoids are specialized metabolites derived from phenylalanine. Glucosinolates are defense compounds derived mainly from methionine and tryptophan in Arabidopsis. It was previously shown that the phenylpropanoid pathway and glucosinolate production are metabolically linked. The accumulation of indole-3-acetaldoxime (IAOx), the precursor of tryptophan-derived glucosinolates, represses phenylpropanoid biosynthesis through accelerated degradation of phenylalanine ammonia lyase (PAL). As PAL functions at the entry point of the phenylpropanoid pathway, which produces indispensable specialized metabolites such as lignin, aldoxime-mediated phenylpropanoid repression is detrimental to plant survival. Although methionine-derived glucosinolates in Arabidopsis are abundant, any impact of aliphatic aldoximes (AAOx) derived from aliphatic amino acids such as methionine on phenylpropanoid production remains unclear. Here, we investigate the impact of AAOx accumulation on phenylpropanoid production using Arabidopsis aldoxime mutants, ref2 and ref5. REF2 and REF5 metabolize aldoximes to respective nitrile oxides redundantly, but with different substrate specificities. ref2 and ref5 mutants have decreased phenylpropanoid contents due to the accumulation of aldoximes. As REF2 and REF5 have high substrate specificity toward AAOx and IAOx, respectively, it was assumed that ref2 accumulates AAOx, not IAOx. Our study indicates that ref2 accumulates both AAOx and IAOx. Removing IAOx partially restored phenylpropanoid content in ref2, but not to the wild-type level. However, when AAOx biosynthesis was silenced, phenylpropanoid production and PAL activity in ref2 were completely restored, suggesting an inhibitory effect of AAOx on phenylpropanoid production. Further feeding studies revealed that the abnormal growth phenotype commonly observed in Arabidopsis mutants lacking AAOx production is a consequence of methionine accumulation.
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Affiliation(s)
- Doosan Shin
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, USA
| | - Veronica C Perez
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL, USA
| | - Gabriella K Dickinson
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL, USA
| | - Haohao Zhao
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, USA
| | - Ru Dai
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, USA
| | - Breanna Tomiczek
- Department of Chemistry, University of Florida, Gainesville, FL, 32611, USA
| | - Keun Ho Cho
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, USA
| | - Ning Zhu
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, 32611, USA
| | - Jin Koh
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, 32611, USA
| | - Alexander Grenning
- Department of Chemistry, University of Florida, Gainesville, FL, 32611, USA
| | - Jeongim Kim
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, USA
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL, USA
- Genetic Institute, University of Florida, Gainesville, FL, USA
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7
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Shin D, Perez VC, Dickinson GK, Zhao H, Dai R, Tomiczek B, Cho KH, Zhu N, Koh J, Grenning A, Kim J. Altered methionine metabolism impacts phenylpropanoid production and plant development in Arabidopsis thaliana. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.29.542770. [PMID: 37398371 PMCID: PMC10312446 DOI: 10.1101/2023.05.29.542770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Phenylpropanoids are specialized metabolites derived from phenylalanine. Glucosinolates are defense compounds derived mainly from methionine and tryptophan in Arabidopsis. It was previously shown that the phenylpropanoid pathway and glucosinolate production are metabolically linked. The accumulation of indole-3-acetaldoxime (IAOx), the precursor of tryptophan-derived glucosinolates, represses phenylpropanoid biosynthesis through accelerated degradation of phenylalanine-ammonia lyase (PAL). As PAL functions at the entry point of the phenylpropanoid pathway which produces indispensable specialized metabolites such as lignin, aldoxime-mediated phenylpropanoid repression is detrimental to plant survival. Although methionine-derived glucosinolates in Arabidopsis are abundant, any impact of aliphatic aldoximes (AAOx) derived from aliphatic amino acids such as methionine on phenylpropanoid production remains unclear. Here, we investigate the impact of AAOx accumulation on phenylpropanoid production using Arabidopsis aldoxime mutants, ref2 and ref5 . REF2 and REF5 metabolize aldoximes to respective nitrile oxides redundantly, but with different substrate specificities. ref2 and ref5 mutants have decreased phenylpropanoid contents due to the accumulation of aldoximes. As REF2 and REF5 have high substrate specificity toward AAOx and IAOx respectively, it was assumed that ref2 accumulates AAOx, not IAOx. Our study indicates that ref2 accumulates both AAOx and IAOx. Removing IAOx partially restored phenylpropanoid production in ref2 , but not to the wild-type level. However, when AAOx biosynthesis was silenced, phenylpropanoid production and PAL activity in ref2 were completely restored, suggesting an inhibitory effect of AAOx on phenylpropanoid production. Further feeding studies revealed that the abnormal growth phenotype commonly observed in Arabidopsis mutants lacking AAOx production is a consequence of methionine accumulation. Significance Statement Aliphatic aldoximes are precursors of various specialized metabolites including defense compounds. This study reveals that aliphatic aldoximes repress phenylpropanoid production and that altered methionine metabolism affects plant growth and development. As phenylpropanoids include vital metabolites such as lignin, a major sink of fixed carbon, this metabolic link may contribute to available resource allocation during defense.
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8
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Perez VC, Zhao H, Lin M, Kim J. Occurrence, Function, and Biosynthesis of the Natural Auxin Phenylacetic Acid (PAA) in Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:266. [PMID: 36678978 PMCID: PMC9867223 DOI: 10.3390/plants12020266] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/14/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Auxins are a class of plant hormones playing crucial roles in a plant's growth, development, and stress responses. Phenylacetic acid (PAA) is a phenylalanine-derived natural auxin found widely in plants. Although the auxin activity of PAA in plants was identified several decades ago, PAA homeostasis and its function remain poorly understood, whereas indole-3-acetic acid (IAA), the most potent auxin, has been used for most auxin studies. Recent studies have revealed unique features of PAA distinctive from IAA, and the enzymes and intermediates of the PAA biosynthesis pathway have been identified. Here, we summarize the occurrence and function of PAA in plants and highlight the recent progress made in PAA homeostasis, emphasizing PAA biosynthesis and crosstalk between IAA and PAA homeostasis.
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Affiliation(s)
- Veronica C. Perez
- Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611, USA
| | - Haohao Zhao
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
| | - Makou Lin
- Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611, USA
| | - Jeongim Kim
- Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611, USA
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
- Genetic Institute, University of Florida, Gainesville, FL 32611, USA
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Perez VC, Dai R, Tomiczek B, Mendoza J, Wolf ESA, Grenning A, Vermerris W, Block AK, Kim J. Metabolic link between auxin production and specialized metabolites in Sorghum bicolor. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:364-376. [PMID: 36300527 PMCID: PMC9786853 DOI: 10.1093/jxb/erac421] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Aldoximes are amino acid derivatives that serve as intermediates for numerous specialized metabolites including cyanogenic glycosides, glucosinolates, and auxins. Aldoxime formation is mainly catalyzed by cytochrome P450 monooxygenases of the 79 family (CYP79s) that can have broad or narrow substrate specificity. Except for SbCYP79A1, aldoxime biosynthetic enzymes in the cereal sorghum (Sorghum bicolor) have not been characterized. This study identified nine CYP79-encoding genes in the genome of sorghum. A phylogenetic analysis of CYP79 showed that SbCYP79A61 formed a subclade with maize ZmCYP79A61, previously characterized to be involved in aldoxime biosynthesis. Functional characterization of this sorghum enzyme using transient expression in Nicotiana benthamiana and stable overexpression in Arabidopsis thaliana revealed that SbCYP79A61 catalyzes the production of phenylacetaldoxime (PAOx) from phenylalanine but, unlike the maize enzyme, displays no detectable activity against tryptophan. Additionally, targeted metabolite analysis after stable isotope feeding assays revealed that PAOx can serve as a precursor of phenylacetic acid (PAA) in sorghum and identified benzyl cyanide as an intermediate of PAOx-derived PAA biosynthesis in both sorghum and maize. Taken together, our results demonstrate that SbCYP79A61 produces PAOx in sorghum and may serve in the biosynthesis of other nitrogen-containing phenylalanine-derived metabolites involved in mediating biotic and abiotic stresses.
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Affiliation(s)
- Veronica C Perez
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32611, USA
| | - Ru Dai
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
| | - Breanna Tomiczek
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Jorrel Mendoza
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, Gainesville, FL 32608, USA
| | - Emily S A Wolf
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32611, USA
| | - Alexander Grenning
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Wilfred Vermerris
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32611, USA
- Department of Microbiology & Cell Science, Gainesville, FL 32611, USA
- UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
- Florida Center for Renewable Chemicals and Fuels, University of Florida, Gainesville, FL 32611, USA
| | - Anna K Block
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, Gainesville, FL 32608, USA
| | - Jeongim Kim
- Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32611, USA
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
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Itoigawa A, Hayakawa T, Zhou Y, Manning AD, Zhang G, Grutzner F, Imai H. Functional Diversity and Evolution of Bitter Taste Receptors in Egg-Laying Mammals. Mol Biol Evol 2022; 39:6591311. [PMID: 35652727 PMCID: PMC9161717 DOI: 10.1093/molbev/msac107] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Egg-laying mammals (monotremes) are a sister clade of therians (placental mammals and marsupials) and a key clade to understand mammalian evolution. They are classified into platypus and echidna, which exhibit distinct ecological features such as habitats and diet. Chemosensory genes, which encode sensory receptors for taste and smell, are believed to adapt to the individual habitats and diet of each mammal. In this study, we focused on the molecular evolution of bitter taste receptors (TAS2Rs) in monotremes. The sense of bitter taste is important to detect potentially harmful substances. We comprehensively surveyed agonists of all TAS2Rs in platypus (Ornithorhynchus anatinus) and short-beaked echidna (Tachyglossus aculeatus) and compared their functions with orthologous TAS2Rs of marsupial and placental mammals (i.e., therians). As results, the agonist screening revealed that the deorphanized monotreme receptors were functionally diversified. Platypus TAS2Rs had broader receptive ranges of agonists than those of echidna TAS2Rs. While platypus consumes a variety of aquatic invertebrates, echidna mainly consumes subterranean social insects (ants and termites) as well as other invertebrates. This result indicates that receptive ranges of TAS2Rs could be associated with feeding habits in monotremes. Furthermore, some orthologous receptors in monotremes and therians responded to β-glucosides, which are feeding deterrents in plants and insects. These results suggest that the ability to detect β-glucosides and other substances might be shared and ancestral among mammals.
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Affiliation(s)
- Akihiro Itoigawa
- Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan.,Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Takashi Hayakawa
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan.,Japan Monkey Centre, Inuyama, Aichi, Japan
| | | | - Adrian D Manning
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, Australia
| | - Guojie Zhang
- Department of Biology, University of Copenhagen, Kobenhavn, Denmark
| | - Frank Grutzner
- School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Hiroo Imai
- Molecular Biology Section, Center for the Evolutionary Origins of Human Behavior, Kyoto University, Inuyama, Aichi, Japan
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11
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A flavin-dependent monooxygenase produces nitrogenous tomato aroma volatiles using cysteine as a nitrogen source. Proc Natl Acad Sci U S A 2022; 119:2118676119. [PMID: 35131946 PMCID: PMC8851548 DOI: 10.1073/pnas.2118676119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2021] [Indexed: 11/19/2022] Open
Abstract
Aroma is an important factor in consumer perception and acceptance of fresh tomatoes and involves a cocktail of several dozen compounds. Tomato fruits produce uncommon nitrogen-containing volatiles derived mainly from the amino acids leucine and phenylalanine. These volatiles have strong positive correlations with consumer liking. We show that an enzyme active in ripening tomatoes is responsible for the production of all nitrogenous volatiles in tomato fruit, at the expense of substrates derived from cysteine and volatile aldehydes. This discovery defines a cysteine-dependent route to nitrogenous volatiles in plants, prompting a reconsideration of the impact of sulfur metabolism on tomato flavor and quality. Tomato (Solanum lycopersicum) produces a wide range of volatile chemicals during fruit ripening, generating a distinct aroma and contributing to the overall flavor. Among these volatiles are several aromatic and aliphatic nitrogen-containing compounds for which the biosynthetic pathways are not known. While nitrogenous volatiles are abundant in tomato fruit, their content in fruits of the closely related species of the tomato clade is highly variable. For example, the green-fruited species Solanum pennellii are nearly devoid, while the red-fruited species S. lycopersicum and Solanum pimpinellifolium accumulate high amounts. Using an introgression population derived from S. pennellii, we identified a locus essential for the production of all the detectable nitrogenous volatiles in tomato fruit. Silencing of the underlying gene (SlTNH1;Solyc12g013690) in transgenic plants abolished production of aliphatic and aromatic nitrogenous volatiles in ripe fruit, and metabolomic analysis of these fruit revealed the accumulation of 2-isobutyl-tetrahydrothiazolidine-4-carboxylic acid, a known conjugate of cysteine and 3-methylbutanal. Biosynthetic incorporation of stable isotope-labeled precursors into 2-isobutylthiazole and 2-phenylacetonitrile confirmed that cysteine provides the nitrogen atom for all nitrogenous volatiles in tomato fruit. Nicotiana benthamiana plants expressing SlTNH1 readily transformed synthetic 2-substituted tetrahydrothiazolidine-4-carboxylic acid substrates into a mixture of the corresponding 2-substituted oxime, nitro, and nitrile volatiles. Distinct from other known flavin-dependent monooxygenase enzymes in plants, this tetrahydrothiazolidine-4-carboxylic acid N-hydroxylase catalyzes sequential hydroxylations. Elucidation of this pathway is a major step forward in understanding and ultimately improving tomato flavor quality.
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Cyanogenesis in the Sorghum Genus: From Genotype to Phenotype. Genes (Basel) 2022; 13:genes13010140. [PMID: 35052482 PMCID: PMC8775130 DOI: 10.3390/genes13010140] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 02/04/2023] Open
Abstract
Domestication has resulted in a loss of genetic diversity in our major food crops, leading to susceptibility to biotic and abiotic stresses linked with climate change. Crop wild relatives (CWR) may provide a source of novel genes potentially important for re-gaining climate resilience. Sorghum bicolor is an important cereal crop with wild relatives that are endemic to Australia. Sorghum bicolor is cyanogenic, but the cyanogenic status of wild Sorghum species is not well known. In this study, leaves of wild species endemic in Australia are screened for the presence of the cyanogenic glucoside dhurrin. The direct measurement of dhurrin content and the potential for dhurrin-derived HCN release (HCNp) showed that all the tested Australian wild species were essentially phenotypically acyanogenic. The unexpected low dhurrin content may reflect the variable and generally nutrient-poor environments in which they are growing in nature. Genome sequencing of six CWR and PCR amplification of the CYP79A1 gene from additional species showed that a high conservation of key amino acids is required for correct protein function and dhurrin synthesis, pointing to the transcriptional regulation of the cyanogenic phenotype in wild sorghum as previously shown in elite sorghum.
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Krönauer C, Lahaye T. The flavin monooxygenase Bs3 triggers cell death in plants, impairs growth in yeast and produces H2O2 in vitro. PLoS One 2021; 16:e0256217. [PMID: 34411175 PMCID: PMC8375990 DOI: 10.1371/journal.pone.0256217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/02/2021] [Indexed: 11/18/2022] Open
Abstract
The pepper resistance gene Bs3 triggers a hypersensitive response (HR) upon transcriptional activation by the corresponding effector protein AvrBs3 from the bacterial pathogen Xanthomonas. Expression of Bs3 in yeast inhibited proliferation, demonstrating that Bs3 function is not restricted to the plant kingdom. The Bs3 sequence shows striking similarity to flavin monooxygenases (FMOs), an FAD- and NADPH-containing enzyme class that is known for the oxygenation of a wide range of substrates and their potential to produce H2O2. Since H2O2 is a hallmark metabolite in plant immunity, we analyzed the role of H2O2 during Bs3 HR. We purified recombinant Bs3 protein from E. coli and confirmed the FMO function of Bs3 with FAD binding and NADPH oxidase activity in vitro. Translational fusion of Bs3 to the redox reporter roGFP2 indicated that the Bs3-dependent HR induces an increase of the intracellular oxidation state in planta. To test if the NADPH oxidation and putative H2O2 production of Bs3 is sufficient to induce HR, we adapted previous studies which have uncovered mutations in the NADPH binding site of FMOs that result in higher NADPH oxidase activity. In vitro studies demonstrated that recombinant Bs3S211A protein has twofold higher NADPH oxidase activity than wildtype Bs3. Translational fusions to roGFP2 showed that Bs3S211A also increased the intracellular oxidation state in planta. Interestingly, while the mutant derivative Bs3S211A had an increase in NADPH oxidase capacity, it did not trigger HR in planta, ultimately revealing that H2O2 produced by Bs3 on its own is not sufficient to trigger HR.
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Affiliation(s)
- Christina Krönauer
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Thomas Lahaye
- University of Tübingen, ZMBP–General Genetics, Tuebingen, Germany
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14
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Hansen CC, Nelson DR, Møller BL, Werck-Reichhart D. Plant cytochrome P450 plasticity and evolution. MOLECULAR PLANT 2021; 14:1244-1265. [PMID: 34216829 DOI: 10.1016/j.molp.2021.06.028] [Citation(s) in RCA: 105] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/28/2021] [Accepted: 06/30/2021] [Indexed: 05/27/2023]
Abstract
The superfamily of cytochrome P450 (CYP) enzymes plays key roles in plant evolution and metabolic diversification. This review provides a status on the CYP landscape within green algae and land plants. The 11 conserved CYP clans known from vascular plants are all present in green algae and several green algae-specific clans are recognized. Clan 71, 72, and 85 remain the largest CYP clans and include many taxa-specific CYP (sub)families reflecting emergence of linage-specific pathways. Molecular features and dynamics of CYP plasticity and evolution are discussed and exemplified by selected biosynthetic pathways. High substrate promiscuity is commonly observed for CYPs from large families, favoring retention of gene duplicates and neofunctionalization, thus seeding acquisition of new functions. Elucidation of biosynthetic pathways producing metabolites with sporadic distribution across plant phylogeny reveals multiple examples of convergent evolution where CYPs have been independently recruited from the same or different CYP families, to adapt to similar environmental challenges or ecological niches. Sometimes only a single or a few mutations are required for functional interconversion. A compilation of functionally characterized plant CYPs is provided online through the Plant P450 Database (erda.dk/public/vgrid/PlantP450/).
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Affiliation(s)
- Cecilie Cetti Hansen
- Plant Biochemistry Laboratory, Department of Plant and Environmental Science, University of Copenhagen, Copenhagen, Denmark; VILLUM Research Center for Plant Plasticity, University of Copenhagen, Copenhagen, Denmark.
| | - David R Nelson
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Birger Lindberg Møller
- Plant Biochemistry Laboratory, Department of Plant and Environmental Science, University of Copenhagen, Copenhagen, Denmark; VILLUM Research Center for Plant Plasticity, University of Copenhagen, Copenhagen, Denmark
| | - Daniele Werck-Reichhart
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg, France.
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Perez VC, Dai R, Bai B, Tomiczek B, Askey BC, Zhang Y, Rubin GM, Ding Y, Grenning A, Block AK, Kim J. Aldoximes are precursors of auxins in Arabidopsis and maize. THE NEW PHYTOLOGIST 2021; 231:1449-1461. [PMID: 33959967 PMCID: PMC8282758 DOI: 10.1111/nph.17447] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/28/2021] [Indexed: 05/03/2023]
Abstract
Two natural auxins, phenylacetic acid (PAA) and indole-3-acetic acid (IAA), play crucial roles in plant growth and development. One route of IAA biosynthesis uses the glucosinolate intermediate indole-3-acetaldoxime (IAOx) as a precursor, which is thought to occur only in glucosinolate-producing plants in Brassicales. A recent study showed that overproducing phenylacetaldoxime (PAOx) in Arabidopsis increases PAA production. However, it remains unknown whether this increased PAA resulted from hydrolysis of PAOx-derived benzyl glucosinolate or, like IAOx-derived IAA, is directly converted from PAOx. If glucosinolate hydrolysis is not required, aldoxime-derived auxin biosynthesis may occur beyond Brassicales. To better understand aldoxime-derived auxin biosynthesis, we conducted an isotope-labelled aldoxime feeding assay using an Arabidopsis glucosinolate-deficient mutant sur1 and maize, and transcriptomics analysis. Our study demonstrated that the conversion of PAOx to PAA does not require glucosinolates in Arabidopsis. Furthermore, maize produces PAA and IAA from PAOx and IAOx, respectively, indicating that aldoxime-derived auxin biosynthesis also occurs in maize. Considering that aldoxime production occurs widely in the plant kingdom, aldoxime-derived auxin biosynthesis is likely to be more widespread than originally believed. A genome-wide transcriptomics study using PAOx-overproduction plants identified complex metabolic networks among IAA, PAA, phenylpropanoid and tryptophan metabolism.
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Affiliation(s)
- Veronica C. Perez
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Ru Dai
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Bing Bai
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Breanna Tomiczek
- Department of Chemistry, University of Florida, Gainesville, FL, 32611
| | - Bryce C. Askey
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
| | - Yi Zhang
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, 32610
| | - Garret M. Rubin
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, 32610
| | - Yousong Ding
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, 32610
| | | | - Anna K. Block
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, Gainesville, FL, 32608
| | - Jeongim Kim
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL, USA
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Paul CE, Eggerichs D, Westphal AH, Tischler D, van Berkel WJH. Flavoprotein monooxygenases: Versatile biocatalysts. Biotechnol Adv 2021; 51:107712. [PMID: 33588053 DOI: 10.1016/j.biotechadv.2021.107712] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/27/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022]
Abstract
Flavoprotein monooxygenases (FPMOs) are single- or two-component enzymes that catalyze a diverse set of chemo-, regio- and enantioselective oxyfunctionalization reactions. In this review, we describe how FPMOs have evolved from model enzymes in mechanistic flavoprotein research to biotechnologically relevant catalysts that can be applied for the sustainable production of valuable chemicals. After a historical account of the development of the FPMO field, we explain the FPMO classification system, which is primarily based on protein structural properties and electron donor specificities. We then summarize the most appealing reactions catalyzed by each group with a focus on the different types of oxygenation chemistries. Wherever relevant, we report engineering strategies that have been used to improve the robustness and applicability of FPMOs.
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Affiliation(s)
- Caroline E Paul
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Daniel Eggerichs
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
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Inoue S, Morita R, Minami Y. An indigo-producing plant, Polygonum tinctorium, possesses a flavin-containing monooxygenase capable of oxidizing indole. Biochem Biophys Res Commun 2020; 534:199-205. [PMID: 33303189 DOI: 10.1016/j.bbrc.2020.11.112] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 11/27/2020] [Indexed: 11/17/2022]
Abstract
Polygonum tinctorium (P. tinctorium) is an indigo plant that is cultivated for a specific metabolite that it produces i.e., indoxyl β-D-glucoside (indican). In this study, flavin-containing monooxygenase (PtFMO) from P. tinctorium was cloned. When recombinant PtFMO was expressed in E. coli in the presence of tryptophan, indigo production was observed. Furthermore, we measured the activity of PtFMO using the membrane fraction from E. coli and found that it could produce indigo using indole as a substrate. The co-expression of PtFMO with indoxyl β-D-glucoside synthase (PtIGS), which catalyzes the glucosylation of indoxyl, brought about the formation of indican in E. coli. The results showed that indican was synthesized by sequential reactions of PtFMO and PtIGS. In three-week-old P. tinctorium specimens, the first leaves demonstrated higher levels of PtFMO expression than the subsequent leaves. This result coincided with that of our prior study on PtIGS expression level. Our study provides evidence that PtFMO might contribute to indican biosynthesis.
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Affiliation(s)
- Shintaro Inoue
- Okayama University of Science, Department of Biochemistry, Faculty of Science, 1-1 Ridai-cho, Kita-ku, Okayama, 700-0005, Japan
| | - Rihito Morita
- Okayama University of Science, Department of Biochemistry, Faculty of Science, 1-1 Ridai-cho, Kita-ku, Okayama, 700-0005, Japan
| | - Yoshiko Minami
- Okayama University of Science, Department of Biochemistry, Faculty of Science, 1-1 Ridai-cho, Kita-ku, Okayama, 700-0005, Japan.
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