1
|
Liu JS, Li YK, Li J, Li Y, Liu ZT, Zhou ZX, Li YG, Wang R. Ascorbate peroxidase catalyses synthesis of protocatechualdehyde from p-hydroxybenzaldehyde in Lycoris aurea. Gene 2024; 927:148697. [PMID: 38880186 DOI: 10.1016/j.gene.2024.148697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 05/10/2024] [Accepted: 06/13/2024] [Indexed: 06/18/2024]
Abstract
Protocatechualdehyde is a plant natural phenolic aldehyde and an active ingredient with important bioactivities in traditional Chinese medicine. Protocatechualdehyde is also a key intermediate in the synthesis of Amaryllidaceae alkaloids for supplying the C6-C1 skeleton. However, the biosynthesis of protocatechualdehyde in plants remains obscure. In this study, we measured the protocatechualdehyde contents in the root, bulb, scape and flower of the Amaryllidaceae plant Lycoris aurea (L'Hér.) Herb., and performed the correlation analysis between the protocatechualdehyde contents and the transcriptional levels of the phenolic oxidization candidate protein encoding genes. We found that a novel ascorbate peroxidase encoded by the contig_24999 in the L. aurea transcriptome database had potential role in the biosynthesis of protocatechualdehyde. The LauAPX_24999 gene was then cloned from the cDNA of the scape of L. aurea. The transient expression of LauAPX_24999 protein in Arabidopsis protoplasts demonstrated that LauAPX_24999 protein was localized in the cytoplasm, thus belonging to Class II L-ascorbate peroxidase. Subsequently, LauAPX_24999 protein was heterogenously expressed in Escherichia coli, and identified that LauAPX_24999 biosynthesized protocatechualdehyde from p-hydroxybenzaldehyde using L-ascorbic acid as the electron donor. The protein structure modelling and molecular docking indicated that p-hydroxybenzaldehyde could access to the active pocket of LauAPX_24999 protein, and reside at the δ-edge of the heme group while L-ascorbic acid binds at the γ-heme edge. To our knowledge, LauAPX_24999 is the first enzyme discovered in plants able to biosynthesize protocatechualdehyde from p-hydroxybenzaldehyde, and offers a competent enzyme resource for the biosynthesis of Amaryllidaceae alkaloids via synthetic biology.
Collapse
Affiliation(s)
- Jin-Shu Liu
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China; Engineering College, Qufu Normal University, Rizhao 276826, China.
| | - Yi-Kui Li
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
| | - Jie Li
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
| | - Yang Li
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
| | - Zheng-Tai Liu
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
| | - Zheng-Xiong Zhou
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Yu-Gang Li
- Engineering College, Qufu Normal University, Rizhao 276826, China.
| | - Ren Wang
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China; Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Nanjing 210014, China.
| |
Collapse
|
2
|
Lv M, Zhang L, Wang Y, Ma L, Yang Y, Zhou X, Wang L, Yu X, Li S. Floral volatile benzenoids/phenylpropanoids: biosynthetic pathway, regulation and ecological value. HORTICULTURE RESEARCH 2024; 11:uhae220. [PMID: 39398951 PMCID: PMC11469922 DOI: 10.1093/hr/uhae220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 07/28/2024] [Indexed: 10/15/2024]
Abstract
Benzenoids/phenylpropanoids, the second most diverse group of plant volatiles, exhibit significant structural diversity and play crucial roles in attracting pollinators and protecting against pathogens, insects, and herbivores. This review summarizes their complex biosynthetic pathways and regulatory mechanisms, highlighting their links to plant growth, development, hormone levels, circadian rhythms, and flower coloration. External factors like light, humidity, and temperature also influence their biosynthesis. Their ecological value is discussed, offering insights for enhancing floral scent, pollinator attraction, pest resistance, and metabolic engineering through genetic modification.
Collapse
Affiliation(s)
- Mengwen Lv
- School of Landscape Architecture, Beijing Forestry University, Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing 100083, China
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Ling Zhang
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yizhou Wang
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Linlin Ma
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong Yang
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Xian Zhou
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liangsheng Wang
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaonan Yu
- School of Landscape Architecture, Beijing Forestry University, Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing 100083, China
| | - Shanshan Li
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
3
|
Busnena BA, Beerhues L, Liu B. Biphenyls and dibenzofurans of the rosaceous subtribe Malinae and their role as phytoalexins. PLANTA 2023; 258:78. [PMID: 37689618 PMCID: PMC10492887 DOI: 10.1007/s00425-023-04228-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 08/23/2023] [Indexed: 09/11/2023]
Abstract
MAIN CONCLUSION Biphenyl and dibenzofuran phytoalexins are differentially distributed among species of the rosaceous subtribe Malinae, which includes apple and pear, and exhibit varying inhibitory activity against phytopathogenic microorganisms. Biphenyls and dibenzofurans are specialized metabolites, which are formed in species of the rosaceous subtribe Malinae upon elicitation by biotic and abiotic inducers. The subtribe Malinae (previously Pyrinae) comprises approximately 1000 species, which include economically important fruit trees such as apple and pear. The present review summarizes the current status of knowledge of biphenyls and dibenzofurans in the Malinae, mainly focusing on their role as phytoalexins. To date, 46 biphenyls and 41 dibenzofurans have been detected in 44 Malinae species. Structurally, 54 simple molecules, 23 glycosidic compounds and 10 miscellaneous structures were identified. Functionally, 21 biphenyls and 21 dibenzofurans were demonstrated to be phytoalexins. Furthermore, their distribution in species of the Malinae, inhibitory activities against phytopathogens, and structure-activity relationships were studied. The most widely distributed phytoalexins of the Malinae are the three biphenyls aucuparin (3), 2'-methoxyaucuparin (7), and 4'-methoxyaucuparin (9) and the three dibenzofurans α-cotonefuran (47), γ-cotonefuran (49), and eriobofuran (53). The formation of biphenyl and dibenzofuran phytoalexins appears to be an essential defense weapon of the Malinae against various stresses. Manipulating phytoalexin formation may enhance the disease resistance in economically important fruit trees. However, this approach requires an extensive understanding of how the compounds are formed. Although the biosynthesis of biphenyls was partially elucidated, formation of dibenzofurans remains largely unclear. Thus, further efforts have to be made to gain deeper insight into the distribution, function, and metabolism of biphenyls and dibenzofurans in the Malinae.
Collapse
Affiliation(s)
- Belnaser A Busnena
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106, Braunschweig, Germany
| | - Ludger Beerhues
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106, Braunschweig, Germany
| | - Benye Liu
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106, Braunschweig, Germany.
| |
Collapse
|
4
|
Huang XQ, Li R, Fu J, Dudareva N. A peroxisomal heterodimeric enzyme is involved in benzaldehyde synthesis in plants. Nat Commun 2022; 13:1352. [PMID: 35292635 PMCID: PMC8924275 DOI: 10.1038/s41467-022-28978-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 02/12/2022] [Indexed: 11/09/2022] Open
Abstract
Benzaldehyde, the simplest aromatic aldehyde, is one of the most wide-spread volatiles that serves as a pollinator attractant, flavor, and antifungal compound. However, the enzyme responsible for its formation in plants remains unknown. Using a combination of in vivo stable isotope labeling, classical biochemical, proteomics and genetic approaches, we show that in petunia benzaldehyde is synthesized via the β-oxidative pathway in peroxisomes by a heterodimeric enzyme consisting of α and β subunits, which belong to the NAD(P)-binding Rossmann-fold superfamily. Both subunits are alone catalytically inactive but, when mixed in equal amounts, form an active enzyme, which exhibits strict substrate specificity towards benzoyl-CoA and uses NADPH as a cofactor. Alpha subunits can form functional heterodimers with phylogenetically distant β subunits, but not all β subunits partner with α subunits, at least in Arabidopsis. Analysis of spatial, developmental and rhythmic expression of genes encoding α and β subunits revealed that expression of the gene for the α subunit likely plays a key role in regulating benzaldehyde biosynthesis. Benzaldehyde is a simple aromatic aldehyde that attracts pollinators, has antifungal properties and contributes to flavor in many plants. Here the authors show that benzaldehyde is synthesized in petunia via the benzoic acid β-oxidative pathway by a peroxisomal heterodimeric enzyme consisting of α and β subunits.
Collapse
Affiliation(s)
- Xing-Qi Huang
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA.,Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Renqiuguo Li
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
| | - Jianxin Fu
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA.,School of Landscape Architecture, Zhejiang Agriculture & Forestry University, 311300, Hangzhou, P.R. China
| | - Natalia Dudareva
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA. .,Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA. .,Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
5
|
Lackus ND, Schmidt A, Gershenzon J, Köllner TG. A peroxisomal β-oxidative pathway contributes to the formation of C6-C1 aromatic volatiles in poplar. PLANT PHYSIOLOGY 2021; 186:891-909. [PMID: 33723573 PMCID: PMC8195509 DOI: 10.1093/plphys/kiab111] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/19/2021] [Indexed: 05/06/2023]
Abstract
Benzenoids (C6-C1 aromatic compounds) play important roles in plant defense and are often produced upon herbivory. Black cottonwood (Populus trichocarpa) produces a variety of volatile and nonvolatile benzenoids involved in various defense responses. However, their biosynthesis in poplar is mainly unresolved. We showed feeding of the poplar leaf beetle (Chrysomela populi) on P. trichocarpa leaves led to increased emission of the benzenoid volatiles benzaldehyde, benzylalcohol, and benzyl benzoate. The accumulation of salicinoids, a group of nonvolatile phenolic defense glycosides composed in part of benzenoid units, was hardly affected by beetle herbivory. In planta labeling experiments revealed that volatile and nonvolatile poplar benzenoids are produced from cinnamic acid (C6-C3). The biosynthesis of C6-C1 aromatic compounds from cinnamic acid has been described in petunia (Petunia hybrida) flowers where the pathway includes a peroxisomal-localized chain shortening sequence, involving cinnamate-CoA ligase (CNL), cinnamoyl-CoA hydratase/dehydrogenase (CHD), and 3-ketoacyl-CoA thiolase (KAT). Sequence and phylogenetic analysis enabled the identification of small CNL, CHD, and KAT gene families in P. trichocarpa. Heterologous expression of the candidate genes in Escherichia coli and characterization of purified proteins in vitro revealed enzymatic activities similar to those described in petunia flowers. RNA interference-mediated knockdown of the CNL subfamily in gray poplar (Populus x canescens) resulted in decreased emission of C6-C1 aromatic volatiles upon herbivory, while constitutively accumulating salicinoids were not affected. This indicates the peroxisomal β-oxidative pathway participates in the formation of volatile benzenoids. The chain shortening steps for salicinoids, however, likely employ an alternative pathway.
Collapse
Affiliation(s)
- Nathalie D Lackus
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Axel Schmidt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
- Author for communication:
| |
Collapse
|
6
|
Werrie PY, Burgeon C, Le Goff GJ, Hance T, Fauconnier ML. Biopesticide Trunk Injection Into Apple Trees: A Proof of Concept for the Systemic Movement of Mint and Cinnamon Essential Oils. FRONTIERS IN PLANT SCIENCE 2021; 12:650132. [PMID: 33897739 PMCID: PMC8063119 DOI: 10.3389/fpls.2021.650132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/05/2021] [Indexed: 05/25/2023]
Abstract
The use of conventional pesticides is debated because of their multiple potential adverse effects on non-target organisms, human health, pest resistance development and environmental contaminations. In this setting, this study focused on developing alternatives, such as trunk-injected essential oil (EO)-based biopesticides. We analysed the ecophysiology of apple trees (Malus domestica) following the injection of Cinnamomum cassia and Mentha spicata nanoemulsions in the tree's vascular system. Targeted and untargeted volatile organic compounds (VOCs) analyses were performed on leaf-contained and leaf-emitted VOCs and analysed through dynamic headspace-gas chromatography-mass spectrometry (DHS-GC-MS) and thermal desorption unit (TDU)-GC-MS. Our results showed that carvone, as a major constituent of the M. spicata EO, was contained in the leaves (mean concentrations ranging from 3.39 to 19.7 ng gDW -1) and emitted at a constant rate of approximately 0.2 ng gDW -1 h-1. Trans-cinnamaldehyde, C. cassia's major component, accumulated in the leaves (mean concentrations of 83.46 and 350.54 ng gDW -1) without being emitted. Furthermore, our results highlighted the increase in various VOCs following EO injection, both in terms of leaf-contained VOCs, such as methyl salicylate, and in terms of leaf-emitted VOCs, such as caryophyllene. Principal component analysis (PCA) highlighted differences in terms of VOC profiles. In addition, an analysis of similarity (ANOSIM) and permutational multivariate analysis of variance (PERMANOVA) revealed that the VOC profiles were significantly impacted by the treatment. Maximum yields of photosystem II (Fv/Fm) were within the range of 0.80-0.85, indicating that the trees remained healthy throughout the experiment. Our targeted analysis demonstrated the systemic translocation of EOs through the plant's vascular system. The untargeted analysis, on the other hand, highlighted the potential systemic acquired resistance (SAR) induction by these EOs. Lastly, C. cassia and M. spicata EOs did not appear phytotoxic to the treated trees, as demonstrated through chlorophyll fluorescence measurements. Hence, this work can be seen as a proof of concept for the use of trunk-injected EOs given the systemic translocation, increased production and release of biogenic VOCs (BVOCs) and absence of phytotoxicity. Further works should focus on the ecological impact of such treatments in orchards, as well as apple quality and production yields.
Collapse
Affiliation(s)
- Pierre-Yves Werrie
- Laboratory of Chemistry of Natural Molecules, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Clément Burgeon
- Laboratory of Chemistry of Natural Molecules, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Guillaume Jean Le Goff
- Biodiversity Research Center, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Thierry Hance
- Biodiversity Research Center, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Marie-Laure Fauconnier
- Laboratory of Chemistry of Natural Molecules, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| |
Collapse
|
7
|
Singh P, Kaufholdt D, Awadalah M, Hänsch R, Beerhues L, Gaid M. Cytosolic aromatic aldehyde dehydrogenase provides benzoic acid for xanthone biosynthesis in Hypericum. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 160:82-93. [PMID: 33482582 DOI: 10.1016/j.plaphy.2021.01.011] [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: 11/16/2020] [Accepted: 01/09/2021] [Indexed: 05/09/2023]
Abstract
Benzoic acid is a building block of a multitude of well-known plant natural products, such as paclitaxel and cocaine. Its simple chemical structure contrasts with its complex biosynthesis. Hypericum species are rich in polyprenylated benzoic acid-derived xanthones, which have received attention due to their biological impact on human health. The upstream biosynthetic sequence leading to xanthones is still incomplete. To supply benzoic acid for xanthone biosynthesis, Hypericum calycinum cell cultures use the CoA-dependent non-β-oxidative pathway, which starts with peroxisomal cinnamate CoA-ligase (HcCNL). Here, we use the xanthone-producing cell cultures to identify the transcript for benzaldehyde dehydrogenase (HcBD), a pivotal player in the non-β-oxidative pathways. In addition to benzaldehyde, the enzyme efficiently catalyzes the oxidation of trans-cinnamaldehyde in vitro. The enzymatic activity is strictly dependent on the presence of NAD+ as co-factor. HcBD is localized to the cytosol upon ectopic expression of reporter fusion constructs. HcBD oxidizes benzaldehyde, which moves across the peroxisome membrane, to form benzoic acid. Increases in the HcCNL and HcBD transcript levels precede the elicitor-induced xanthone accumulation. The current work addresses a crucial step in the yet incompletely understood CoA-dependent non-β-oxidative route of benzoic acid biosynthesis. Addressing this step may offer a new biotechnological tool to enhance product formation in biofactories.
Collapse
Affiliation(s)
- Poonam Singh
- Technische Universität Braunschweig, Institute of Pharmaceutical Biology, Mendelssohnstraße 1, Braunschweig, 38106, Germany
| | - David Kaufholdt
- Technische Universität Braunschweig, Institute of Plant Biology, Humboldtstraße 1, Braunschweig, 38106, Germany
| | - Mina Awadalah
- Technische Universität Braunschweig, Institute of Pharmaceutical Biology, Mendelssohnstraße 1, Braunschweig, 38106, Germany
| | - Robert Hänsch
- Technische Universität Braunschweig, Institute of Plant Biology, Humboldtstraße 1, Braunschweig, 38106, Germany; Center of Molecular Ecophysiology (CMEP), College of Resources and Environment, Southwest University, No. 2, Tiansheng Road, Beibei District, 400715, Chongqing, PR China
| | - Ludger Beerhues
- Technische Universität Braunschweig, Institute of Pharmaceutical Biology, Mendelssohnstraße 1, Braunschweig, 38106, Germany; Technische Universität Braunschweig, Centre of Pharmaceutical Engineering, Franz-Liszt-Straße 35 A, Braunschweig, 38106, Germany
| | - Mariam Gaid
- Technische Universität Braunschweig, Institute of Pharmaceutical Biology, Mendelssohnstraße 1, Braunschweig, 38106, Germany; Technische Universität Braunschweig, Centre of Pharmaceutical Engineering, Franz-Liszt-Straße 35 A, Braunschweig, 38106, Germany.
| |
Collapse
|
8
|
Singh P, Preu L, Beuerle T, Kaufholdt D, Hänsch R, Beerhues L, Gaid M. A promiscuous coenzyme A ligase provides benzoyl-coenzyme A for xanthone biosynthesis in Hypericum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1472-1490. [PMID: 33031578 DOI: 10.1111/tpj.15012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/11/2020] [Accepted: 09/23/2020] [Indexed: 05/09/2023]
Abstract
Benzoic acid-derived compounds, such as polyprenylated benzophenones and xanthones, attract the interest of scientists due to challenging chemical structures and diverse biological activities. The genus Hypericum is of high medicinal value, as exemplified by H. perforatum. It is rich in benzophenone and xanthone derivatives, the biosynthesis of which requires the catalytic activity of benzoate-coenzyme A (benzoate-CoA) ligase (BZL), which activates benzoic acid to benzoyl-CoA. Despite remarkable research so far done on benzoic acid biosynthesis in planta, all previous structural studies of BZL genes and proteins are exclusively related to benzoate-degrading microorganisms. Here, a transcript for a plant acyl-activating enzyme (AAE) was cloned from xanthone-producing Hypericum calycinum cell cultures using transcriptomic resources. An increase in the HcAAE1 transcript level preceded xanthone accumulation after elicitor treatment, as previously observed with other pathway-related genes. Subcellular localization of reporter fusions revealed the dual localization of HcAAE1 to cytosol and peroxisomes owing to a type 2 peroxisomal targeting signal. This result suggests the generation of benzoyl-CoA in Hypericum by the CoA-dependent non-β-oxidative route. A luciferase-based substrate specificity assay and the kinetic characterization indicated that HcAAE1 exhibits promiscuous substrate preference, with benzoic acid being the sole aromatic substrate accepted. Unlike 4-coumarate-CoA ligase and cinnamate-CoA ligase enzymes, HcAAE1 did not accept 4-coumaric and cinnamic acids, respectively. The substrate preference was corroborated by in silico modeling, which indicated valid docking of both benzoic acid and its adenosine monophosphate intermediate in the HcAAE1/BZL active site cavity.
Collapse
Affiliation(s)
- Poonam Singh
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, Braunschweig, 38106, Germany
| | - Lutz Preu
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Beethovenstraße 55, Braunschweig, 38106, Germany
| | - Till Beuerle
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, Braunschweig, 38106, Germany
| | - David Kaufholdt
- Institute of Plant Biology, Technische Universität Braunschweig, Humboldtstraße 1, Braunschweig, 38106, Germany
| | - Robert Hänsch
- Institute of Plant Biology, Technische Universität Braunschweig, Humboldtstraße 1, Braunschweig, 38106, Germany
- Center of Molecular Ecophysiology (CMEP) - College of Resources and Environment, Southwest University No. 2, Tiansheng Road, Chongqing, 400715, P.R. China
| | - Ludger Beerhues
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, Braunschweig, 38106, Germany
- Centre of Pharmaceutical Engineering, Technische Universität Braunschweig, Franz-Liszt-Straße 35 A, Braunschweig, 38106, Germany
| | - Mariam Gaid
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, Braunschweig, 38106, Germany
- Centre of Pharmaceutical Engineering, Technische Universität Braunschweig, Franz-Liszt-Straße 35 A, Braunschweig, 38106, Germany
| |
Collapse
|
9
|
Saini SS, Gaid M, Sircar D. Benzoate-CoA ligase contributes to the biosynthesis of biphenyl phytoalexins in elicitor-treated pear cell cultures. PLANT CELL REPORTS 2020; 39:207-215. [PMID: 31713663 DOI: 10.1007/s00299-019-02484-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/26/2019] [Indexed: 05/09/2023]
Abstract
Benzoate-Coenzyme A ligase enzyme activity catalyzing the conversion of free benzoic acid to benzoyl-CoA was detected and biochemically characterized in the elicitor-treated pear cell cultures. Asian pear (Pyrus pyrifolia) is an economically and nutritionally important fruit-bearing tree of the subtribe Malinae. Upon pathogen attack, pears produce unique benzoate-derived biphenyl phytoalexins. The upstream biosynthesis of the biphenyl in Malinae is still incomplete. Previously, protein preparations from yeast extract-treated pear cultures were able to convert L-phenylalanine to cinnamic acid catalyzed by the activity of the phenylalanine ammonia lyase. The same extract was able to perform a C2 side-chain cleavage of cinnamic acid to benzaldehyde followed by oxidation of the latter to benzoic acid owing to the molecularly-undefined benzaldehyde synthase and benzaldehyde dehydrogenase activities, respectively. The biosynthesis of biphenyls starts with benzoate-Coenzyme A ligase (BZL), which converts benzoic acid to benzoyl-CoA. Subsequently, the previously-defined biphenyl synthase uses benzoyl-CoA to form the biphenyls. The current study reports the first time detection and characterization of BZL activity in elicitor-treated pear cell cultures. The preferred substrate was benzoic acid (Km = 62 ± 4 µM). Magnesium or manganese was prerequisite for the activity, which was enhanced by ~ 70% in the presence of potassium. Maximum BZL activity was observed 18 h post elicitation, which is in agreement with the coordinate induction reported for the enzymes in the same pathway. The induced BZL activity preceded the accumulation of biphenyls supporting its involvement in their biosynthesis.
Collapse
Affiliation(s)
- Shashank Sagar Saini
- Plant Molecular Biology Group, Biotechnology Department, Indian Institute of Technology Roorkee, Roorkee, 247 667, India
| | - Mariam Gaid
- Technische Universität Braunschweig, Institute of Pharmaceutical Biology, Mendelssohnstrasse 1, 38106, Braunschweig, Germany
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
| | - Debabrata Sircar
- Plant Molecular Biology Group, Biotechnology Department, Indian Institute of Technology Roorkee, Roorkee, 247 667, India.
| |
Collapse
|