1
|
Zeng J, Liu X, Dong Z, Zhang F, Qiu F, Zhong M, Zhao T, Yang C, Zeng L, Lan X, Zhang H, Zhou J, Chen M, Tang K, Liao Z. Discovering a mitochondrion-localized BAHD acyltransferase involved in calystegine biosynthesis and engineering the production of 3β-tigloyloxytropane. Nat Commun 2024; 15:3623. [PMID: 38684703 PMCID: PMC11058270 DOI: 10.1038/s41467-024-47968-0] [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: 11/16/2023] [Accepted: 04/15/2024] [Indexed: 05/02/2024] Open
Abstract
Solanaceous plants produce tropane alkaloids (TAs) via esterification of 3α- and 3β-tropanol. Although littorine synthase is revealed to be responsible for 3α-tropanol esterification that leads to hyoscyamine biosynthesis, the genes associated with 3β-tropanol esterification are unknown. Here, we report that a BAHD acyltransferase from Atropa belladonna, 3β-tigloyloxytropane synthase (TS), catalyzes 3β-tropanol and tigloyl-CoA to form 3β-tigloyloxytropane, the key intermediate in calystegine biosynthesis and a potential drug for treating neurodegenerative disease. Unlike other cytosolic-localized BAHD acyltransferases, TS is localized to mitochondria. The catalytic mechanism of TS is revealed through molecular docking and site-directed mutagenesis. Subsequently, 3β-tigloyloxytropane is synthesized in tobacco. A bacterial CoA ligase (PcICS) is found to synthesize tigloyl-CoA, an acyl donor for 3β-tigloyloxytropane biosynthesis. By expressing TS mutant and PcICS, engineered Escherichia coli synthesizes 3β-tigloyloxytropane from tiglic acid and 3β-tropanol. This study helps to characterize the enzymology and chemodiversity of TAs and provides an approach for producing 3β-tigloyloxytropane.
Collapse
Affiliation(s)
- Junlan Zeng
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xiaoqiang Liu
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Zhaoyue Dong
- College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
| | - Fangyuan Zhang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Fei Qiu
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Mingyu Zhong
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Tengfei Zhao
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Chunxian Yang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Lingjiang Zeng
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Xiaozhong Lan
- TAAHC-SWU Medicinal Plant Joint R&D Centre, The Provincial and Ministerial Co-founded Collaborative Innovation Center for R&D in Xizang Characteristic Agricultural and Animal Husbandry Resources, Xizang Agricultural and Animal Husbandry College, Nyingchi, 860000, China
| | - Hongbo Zhang
- Key Laboratory of Synthetic Biology of Ministry of Agriculture and Rural Affairs, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Junhui Zhou
- State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Min Chen
- College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
| | - Kexuan Tang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China
- Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhihua Liao
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, State Key Laboratory of Resource Insects, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing, 400715, China.
| |
Collapse
|
2
|
Fiesel PD, Kerwin RE, Daniel Jones A, Last RL. Trading acyls and swapping sugars: metabolic innovations in Solanum trichomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.05.542877. [PMID: 37333341 PMCID: PMC10274652 DOI: 10.1101/2023.06.05.542877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Solanaceae (nightshade family) species synthesize a remarkable array of clade- and tissue-specific specialized metabolites. Protective acylsugars, one such class of structurally diverse metabolites, are produced by AcylSugar AcylTransferases from sugars and acyl-coenzyme A esters. Published research revealed trichome acylsugars composed of glucose and sucrose cores in species across the family. In addition, acylsugars were analyzed across a small fraction of the >1200 species in the phenotypically megadiverse Solanum genus, with a handful containing inositol and glycosylated inositol cores. The current study sampled several dozen species across subclades of the Solanum to get a more detailed view of acylsugar chemodiversity. In depth characterization of acylsugars from the Clade II species Solanum melongena (brinjal eggplant) led to the identification of eight unusual structures with inositol or inositol glycoside cores, and hydroxyacyl chains. Liquid chromatography-mass spectrometry analysis of 31 additional species in the Solanum genus revealed striking acylsugar diversity with some traits restricted to specific clades and species. Acylinositols and inositol-based acyldisaccharides were detected throughout much of the genus. In contrast, acylglucoses and acylsucroses were more restricted in distribution. Analysis of tissue-specific transcriptomes and interspecific acylsugar acetylation differences led to the identification of the S. melongena AcylSugar AcylTransferase 3-Like 1 (SmASAT3-L1; SMEL4.1_12g015780) enzyme. This enzyme is distinct from previously characterized acylsugar acetyltransferases, which are in the ASAT4 clade, and appears to be a functionally divergent ASAT3. This study provides a foundation for investigating the evolution and function of diverse Solanum acylsugar structures and harnessing this diversity in breeding and synthetic biology.
Collapse
Affiliation(s)
- Paul D. Fiesel
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823 USA
| | - Rachel E. Kerwin
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823 USA
| | - A. Daniel Jones
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823 USA
| | - Robert L. Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823 USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48823 USA
| |
Collapse
|
3
|
Shoji T, Sugawara S, Mori T, Kobayashi M, Kusano M, Saito K. Induced production of specialized steroids by transcriptional reprogramming in Petunia hybrida. PNAS NEXUS 2023; 2:pgad326. [PMID: 37920550 PMCID: PMC10619512 DOI: 10.1093/pnasnexus/pgad326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/25/2023] [Indexed: 11/04/2023]
Abstract
Plants produce specialized metabolites with defensive properties that are often synthesized through the coordinated regulation of metabolic genes by transcription factors in various biological contexts. In this study, we investigated the regulatory function of the transcription factor PhERF1 from petunia (Petunia hybrida), which belongs to a small group of ETHYLENE RESPONSE FACTOR (ERF) family members that regulate the biosynthesis of bioactive alkaloids and terpenoids in various plant lineages. We examined the effects of transiently overexpressing PhERF1 in petunia leaves on the transcriptome and metabolome, demonstrating the production of a class of specialized steroids, petuniolides, and petuniasterones in these leaves. We also observed the activation of many metabolic genes, including those involved in sterol biosynthesis, as well as clustered genes that encode new metabolic enzymes, such as cytochrome P450 oxidoreductases, 2-oxoglutarate-dependent dioxygenases, and BAHD acyltransferases. Furthermore, we determined that PhERF1 transcriptionally induces downstream metabolic genes by recognizing specific cis-regulatory elements in their promoters. This study highlights the potential of evolutionarily conserved transcriptional regulators to induce the production of specialized products through transcriptional reprogramming.
Collapse
Affiliation(s)
- Tsubasa Shoji
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
- Institute of Natural Medicine, University of Toyama, Toyama, Toyama 930-0194, Japan
| | - Satoko Sugawara
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
| | - Tetsuya Mori
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
| | - Makoto Kobayashi
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
| | - Miyako Kusano
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
- Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Tsukuba-Plant Innovation Research Center (T-PIRC), University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Kazuki Saito
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan
| |
Collapse
|
4
|
Liu L, Xu H, Zhang W, Xing J, Zhu M, Zhang Y, Wang Y. Genome-Wide Analysis of the BAHD Family in Welsh Onion and CER2-LIKEs Involved in Wax Metabolism. Genes (Basel) 2023; 14:1286. [PMID: 37372466 DOI: 10.3390/genes14061286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
BAHD acyltransferases (BAHDs), especially those present in plant epidermal wax metabolism, are crucial for environmental adaptation. Epidermal waxes primarily comprise very-long-chain fatty acids (VLCFAs) and their derivatives, serving as significant components of aboveground plant organs. These waxes play an essential role in resisting biotic and abiotic stresses. In this study, we identified the BAHD family in Welsh onion (Allium fistulosum). Our analysis revealed the presence of AfBAHDs in all chromosomes, with a distinct concentration in Chr3. Furthermore, the cis-acting elements of AfBAHDs were associated with abiotic/biotic stress, hormones, and light. The motif of Welsh onion BAHDs indicated the presence of a specific BAHDs motif. We also established the phylogenetic relationships of AfBAHDs, identifying three homologous genes of CER2. Subsequently, we characterized the expression of AfCER2-LIKEs in a Welsh onion mutant deficient in wax and found that AfCER2-LIKE1 plays a critical role in leaf wax metabolism, while all AfCER2-LIKEs respond to abiotic stress. Our findings provide new insights into the BAHD family and lay a foundation for future studies on the regulation of wax metabolism in Welsh onion.
Collapse
Affiliation(s)
- Lecheng Liu
- College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China
| | - Huanhuan Xu
- College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing Key Laboratory of Vegetable Germplasm Improvement, National Engineering Research Center for Vegetables, Beijing 100097, China
| | - Wanyue Zhang
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing Key Laboratory of Vegetable Germplasm Improvement, National Engineering Research Center for Vegetables, Beijing 100097, China
| | - Jiayi Xing
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing Key Laboratory of Vegetable Germplasm Improvement, National Engineering Research Center for Vegetables, Beijing 100097, China
- Department of Horticulture, Agricultural College, Shihezi University, Shihezi 832003, China
| | - Mingzhao Zhu
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing Key Laboratory of Vegetable Germplasm Improvement, National Engineering Research Center for Vegetables, Beijing 100097, China
| | - Yuchen Zhang
- College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing Key Laboratory of Vegetable Germplasm Improvement, National Engineering Research Center for Vegetables, Beijing 100097, China
| | - Yongqin Wang
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing Key Laboratory of Vegetable Germplasm Improvement, National Engineering Research Center for Vegetables, Beijing 100097, China
| |
Collapse
|
5
|
Ji W, Mandal S, Rezenom YH, McKnight TD. Specialized metabolism by trichome-enriched Rubisco and fatty acid synthase components. PLANT PHYSIOLOGY 2023; 191:1199-1213. [PMID: 36264116 PMCID: PMC9922422 DOI: 10.1093/plphys/kiac487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Acylsugars, specialized metabolites with defense activities, are secreted by trichomes of many solanaceous plants. Several acylsugar metabolic genes (AMGs) remain unknown. We previously reported multiple candidate AMGs. Here, using multiple approaches, we characterized additional AMGs. First, we identified differentially expressed genes between high- and low-acylsugar-producing F2 plants derived from a cross between cultivated tomato (Solanum lycopersicum) and a wild relative (Solanum pennellii), which produce acylsugars that are ∼1% and ∼20% of leaf dry weight, respectively. Expression levels of many known and candidate AMGs positively correlated with acylsugar amounts in F2 individuals. Next, we identified lycopersicum-pennellii putative orthologs with higher nonsynonymous to synonymous substitutions. These analyses identified four candidate genes, three of which showed enriched expression in stem trichomes compared to underlying tissues (shaved stems). Virus-induced gene silencing confirmed two candidates, Sopen05g009610 [beta-ketoacyl-(acyl-carrier-protein) reductase; fatty acid synthase component] and Sopen07g006810 (Rubisco small subunit), as AMGs. Phylogenetic analysis indicated that Sopen05g009610 is distinct from specialized metabolic cytosolic reductases but closely related to two capsaicinoid biosynthetic reductases, suggesting evolutionary relationship between acylsugar and capsaicinoid biosynthesis. Analysis of publicly available datasets revealed enriched expression of Sopen05g009610 orthologs in trichomes of several acylsugar-producing species. Similarly, orthologs of Sopen07g006810 were identified as solanaceous trichome-enriched members, which form a phylogenetic clade distinct from those of mesophyll-expressed "regular" Rubisco small subunits. Furthermore, δ13C analyses indicated recycling of metabolic CO2 into acylsugars by Sopen07g006810 and showed how trichomes support high levels of specialized metabolite production. These findings have implications for genetic manipulation of trichome-specialized metabolism in solanaceous crops.
Collapse
Affiliation(s)
| | | | - Yohannes H Rezenom
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | | |
Collapse
|
6
|
Schenck CA, Anthony TM, Jacobs M, Jones AD, Last RL. Natural variation meets synthetic biology: Promiscuous trichome-expressed acyltransferases from Nicotiana. PLANT PHYSIOLOGY 2022; 190:146-164. [PMID: 35477794 PMCID: PMC9434288 DOI: 10.1093/plphys/kiac192] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
Acylsugars are defensive, trichome-synthesized sugar esters produced in plants across the Solanaceae (nightshade) family. Although assembled from simple metabolites and synthesized by a relatively short core biosynthetic pathway, tremendous within- and across-species acylsugar structural variation is documented across the family. To advance our understanding of the diversity and the synthesis of acylsugars within the Nicotiana genus, trichome extracts were profiled across the genus coupled with transcriptomics-guided enzyme discovery and in vivo and in vitro analysis. Differences in the types of sugar cores, numbers of acylations, and acyl chain structures contributed to over 300 unique annotated acylsugars throughout Nicotiana. Placement of acyl chain length into a phylogenetic context revealed that an unsaturated acyl chain type was detected in a few closely related species. A comparative transcriptomics approach identified trichome-enriched Nicotiana acuminata acylsugar biosynthetic candidate enzymes. More than 25 acylsugar variants could be produced in a single enzyme assay with four N. acuminata acylsugar acyltransferases (NacASAT1-4) together with structurally diverse acyl-CoAs and sucrose. Liquid chromatography coupled with mass spectrometry screening of in vitro products revealed the ability of these enzymes to make acylsugars not present in Nicotiana plant extracts. In vitro acylsugar production also provided insights into acyltransferase acyl donor promiscuity and acyl acceptor specificity as well as regiospecificity of some ASATs. This study suggests that promiscuous Nicotiana acyltransferases can be used as synthetic biology tools to produce novel and potentially useful metabolites.
Collapse
Affiliation(s)
- Craig A Schenck
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Thilani M Anthony
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - MacKenzie Jacobs
- Department of Physical Sciences and Mathematics, West Liberty University, West Liberty, West Virginia 26074, USA
| | - A Daniel Jones
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Robert L Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA
| |
Collapse
|
7
|
Fiesel PD, Parks HM, Last RL, Barry CS. Fruity, sticky, stinky, spicy, bitter, addictive, and deadly: evolutionary signatures of metabolic complexity in the Solanaceae. Nat Prod Rep 2022; 39:1438-1464. [PMID: 35332352 PMCID: PMC9308699 DOI: 10.1039/d2np00003b] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Covering: 2000-2022Plants collectively synthesize a huge repertoire of metabolites. General metabolites, also referred to as primary metabolites, are conserved across the plant kingdom and are required for processes essential to growth and development. These include amino acids, sugars, lipids, and organic acids. In contrast, specialized metabolites, historically termed secondary metabolites, are structurally diverse, exhibit lineage-specific distribution and provide selective advantage to host species to facilitate reproduction and environmental adaptation. Due to their potent bioactivities, plant specialized metabolites attract considerable attention for use as flavorings, fragrances, pharmaceuticals, and bio-pesticides. The Solanaceae (Nightshade family) consists of approximately 2700 species and includes crops of significant economic, cultural, and scientific importance: these include potato, tomato, pepper, eggplant, tobacco, and petunia. The Solanaceae has emerged as a model family for studying the biochemical evolution of plant specialized metabolism and multiple examples exist of lineage-specific metabolites that influence the senses and physiology of commensal and harmful organisms, including humans. These include, alcohols, phenylpropanoids, and carotenoids that contribute to fruit aroma and color in tomato (fruity), glandular trichome-derived terpenoids and acylsugars that contribute to plant defense (stinky & sticky, respectively), capsaicinoids in chilli-peppers that influence seed dispersal (spicy), and steroidal glycoalkaloids (bitter) from Solanum, nicotine (addictive) from tobacco, as well as tropane alkaloids (deadly) from Deadly Nightshade that deter herbivory. Advances in genomics and metabolomics, coupled with the adoption of comparative phylogenetic approaches, resulted in deeper knowledge of the biosynthesis and evolution of these metabolites. This review highlights recent progress in this area and outlines opportunities for - and challenges of-developing a more comprehensive understanding of Solanaceae metabolism.
Collapse
Affiliation(s)
- Paul D Fiesel
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Hannah M Parks
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Robert L Last
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Cornelius S Barry
- Department of Horticulture, Michigan State University, East Lansing, MI 48824, USA.
| |
Collapse
|
8
|
Feng H, Acosta-Gamboa L, Kruse LH, Tracy JD, Chung SH, Nava Fereira AR, Shakir S, Xu H, Sunter G, Gore MA, Casteel CL, Moghe GD, Jander G. Acylsugars protect Nicotiana benthamiana against insect herbivory and desiccation. PLANT MOLECULAR BIOLOGY 2022; 109:505-522. [PMID: 34586580 DOI: 10.1007/s11103-021-01191-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 09/12/2021] [Indexed: 06/13/2023]
Abstract
KEY MESSAGE Nicotiana benthamiana acylsugar acyltransferase (ASAT) is required for protection against desiccation and insect herbivory. Knockout mutations provide a new resource for investigation of plant-aphid and plant-whitefly interactions. Nicotiana benthamiana is used extensively as a transient expression platform for functional analysis of genes from other species. Acylsugars, which are produced in the trichomes, are a hypothesized cause of the relatively high insect resistance that is observed in N. benthamiana. We characterized the N. benthamiana acylsugar profile, bioinformatically identified two acylsugar acyltransferase genes, ASAT1 and ASAT2, and used CRISPR/Cas9 mutagenesis to produce acylsugar-deficient plants for investigation of insect resistance and foliar water loss. Whereas asat1 mutations reduced accumulation, asat2 mutations caused almost complete depletion of foliar acylsucroses. Three hemipteran and three lepidopteran herbivores survived, gained weight, and/or reproduced significantly better on asat2 mutants than on wildtype N. benthamiana. Both asat1 and asat2 mutations reduced the water content and increased leaf temperature. Our results demonstrate the specific function of two ASAT proteins in N. benthamiana acylsugar biosynthesis, insect resistance, and desiccation tolerance. The improved growth of aphids and whiteflies on asat2 mutants will facilitate the use of N. benthamiana as a transient expression platform for the functional analysis of insect effectors and resistance genes from other plant species. Similarly, the absence of acylsugars in asat2 mutants will enable analysis of acylsugar biosynthesis genes from other Solanaceae by transient expression.
Collapse
Affiliation(s)
- Honglin Feng
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
| | - Lucia Acosta-Gamboa
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Lars H Kruse
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Jake D Tracy
- Plant-Microbe Biology and Plant Pathology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717, USA
| | | | - Alba Ruth Nava Fereira
- Department of Biology, University of Texas San Antonio, San Antonio, TX, 78249, USA
- Department of Biological Sciences, Northern Illinois University, Dekalb, IL, 60115, USA
| | - Sara Shakir
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
- Gembloux Agro-Bio Tech Institute, The University of Liege, Gembloux, Belgium
| | - Hongxing Xu
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
- College of Life Science, The Shaanxi Normal University, Xi'an, China
| | - Garry Sunter
- Department of Biology, University of Texas San Antonio, San Antonio, TX, 78249, USA
- Department of Biological Sciences, Northern Illinois University, Dekalb, IL, 60115, USA
| | - Michael A Gore
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Clare L Casteel
- Plant-Microbe Biology and Plant Pathology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Gaurav D Moghe
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Georg Jander
- Boyce Thompson Institute, Ithaca, NY, 14853, USA.
| |
Collapse
|
9
|
Chang A, Hu Z, Chen B, Vanderschuren H, Chen M, Qu Y, Yu W, Li Y, Sun H, Cao J, Vasudevan K, Li C, Cao Y, Zhang J, Shen Y, Yang A, Wang Y. Characterization of trichome-specific BAHD acyltransferases involved in acylsugar biosynthesis in Nicotiana tabacum. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3913-3928. [PMID: 35262703 DOI: 10.1093/jxb/erac095] [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: 11/08/2021] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Glandular trichomes of tobacco (Nicotiana tabacum) produce blends of acylsucroses that contribute to defence against pathogens and herbivorous insects, but the mechanism of assembly of these acylsugars has not yet been determined. In this study, we isolated and characterized two trichome-specific acylsugar acyltransferases that are localized in the endoplasmic reticulum, NtASAT1 and NtASAT2. They sequentially catalyse two additive steps of acyl donors to sucrose to produce di-acylsucrose. Knocking out of NtASAT1 or NtASAT2 resulted in deficiency of acylsucrose; however, there was no effect on acylsugar accumulation in plants overexpressing NtASAT1 or NtASAT2. Genomic analysis and profiling revealed that NtASATs originated from the T subgenome, which is derived from the acylsugar-producing diploid ancestor N. tomentosiformis. Our identification of NtASAT1 and NtASAT2 as enzymes involved in acylsugar assembly in tobacco potentially provides a new approach and target genes for improving crop resistance against pathogens and insects.
Collapse
Affiliation(s)
- Aixia Chang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
- Plant Genetics Laboratory, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
| | - Zhongyi Hu
- Jiangxi Food Inspection and Testing Research Institute, Nanchang, 330001, China
| | - Biao Chen
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Herve Vanderschuren
- Plant Genetics Laboratory, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
- Tropical Crop Improvement Lab, Department of Biosystems, KU Leuven, Heverlee, Belgium
| | - Ming Chen
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Yafang Qu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Weisong Yu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Yangyang Li
- Hunan Tobacco Research Institute, Changsha, 410004, China
| | - Huiqing Sun
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Jianmin Cao
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Kumar Vasudevan
- Plant Genetics Laboratory, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
| | - Chenying Li
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Yanan Cao
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Jianye Zhang
- Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China
| | - Yeming Shen
- Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China
| | - Aiguo Yang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Yuanying Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| |
Collapse
|
10
|
Leong BJ, Hurney S, Fiesel P, Anthony TM, Moghe G, Jones AD, Last RL. Identification of BAHD acyltransferases associated with acylinositol biosynthesis in Solanum quitoense (naranjilla). PLANT DIRECT 2022; 6:e415. [PMID: 35774622 PMCID: PMC9219006 DOI: 10.1002/pld3.415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/26/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
Plants make a variety of specialized metabolites that can mediate interactions with animals, microbes, and competitor plants. Understanding how plants synthesize these compounds enables studies of their biological roles by manipulating their synthesis in vivo as well as producing them in vitro. Acylsugars are a group of protective metabolites that accumulate in the trichomes of many Solanaceae family plants. Acylinositol biosynthesis is of interest because it appears to be restricted to a subgroup of species within the Solanum genus. Previous work characterized a triacylinositol acetyltransferase involved in acylinositol biosynthesis in the Andean fruit plant Solanum quitoense (lulo or naranjilla). We characterized three additional S. quitoense trichome expressed enzymes and found that virus-induced gene silencing of each caused changes in acylinositol accumulation. pH was shown to influence the stability and rearrangement of the product of ASAT1H and could potentially play a role in acylinositol biosynthesis. Surprisingly, the in vitro triacylinositol products of these enzymes are distinct from those that accumulate in planta. This suggests that additional enzymes are required in acylinositol biosynthesis. These characterized S. quitoense enzymes, nonetheless, provide opportunities to test the biological impact and properties of these triacylinositols in vitro.
Collapse
Affiliation(s)
- Bryan J. Leong
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
- Present address:
Horticultural Sciences DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Steven Hurney
- Department of ChemistryMichigan State UniversityEast LansingMichiganUSA
- Present address:
Michigan Department of Health and Human ServicesLansingMichiganUSA
| | - Paul Fiesel
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Thilani M. Anthony
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Gaurav Moghe
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Present address:
Plant Biology Section, School of Integrative Plant SciencesCornell UniversityIthacaNew YorkUSA
| | - Arthur Daniel Jones
- Department of ChemistryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Robert L. Last
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| |
Collapse
|
11
|
The Genetic Complexity of Type-IV Trichome Development Reveals the Steps towards an Insect-Resistant Tomato. PLANTS 2022; 11:plants11101309. [PMID: 35631734 PMCID: PMC9148003 DOI: 10.3390/plants11101309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/11/2022] [Accepted: 05/11/2022] [Indexed: 11/18/2022]
Abstract
The leaves of the wild tomato Solanum galapagense harbor type-IV glandular trichomes (GT) that produce high levels of acylsugars (AS), conferring insect resistance. Conversely, domesticated tomatoes (S. lycopersicum) lack type-IV trichomes on the leaves of mature plants, preventing high AS production, thus rendering the plants more vulnerable to insect predation. We hypothesized that cultivated tomatoes engineered to harbor type-IV trichomes on the leaves of adult plants could be insect-resistant. We introgressed the genetic determinants controlling type-IV trichome development from S. galapagense into cv. Micro-Tom (MT) and created a line named “Galapagos-enhanced trichomes” (MT-Get). Mapping-by-sequencing revealed that five chromosomal regions of S. galapagense were present in MT-Get. Further genetic mapping showed that S. galapagense alleles in chromosomes 1, 2, and 3 were sufficient for the presence of type-IV trichomes on adult organs but at lower densities. Metabolic and gene expression analyses demonstrated that type-IV trichome density was not accompanied by the AS production and exudation in MT-Get. Although the plants produce a significant amount of acylsugars, those are still not enough to make them resistant to whiteflies. We demonstrate that type-IV glandular trichome development is insufficient for high AS accumulation. The results from our study provided additional insights into the steps necessary for breeding an insect-resistant tomato.
Collapse
|
12
|
Lou YR, Anthony TM, Fiesel PD, Arking RE, Christensen EM, Jones AD, Last RL. It happened again: Convergent evolution of acylglucose specialized metabolism in black nightshade and wild tomato. SCIENCE ADVANCES 2021; 7:eabj8726. [PMID: 34757799 PMCID: PMC8580325 DOI: 10.1126/sciadv.abj8726] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 09/20/2021] [Indexed: 05/09/2023]
Abstract
Plants synthesize myriad phylogenetically restricted specialized (aka “secondary”) metabolites with diverse structures. Metabolism of acylated sugar esters in epidermal glandular secreting trichomes across the Solanaceae (nightshade) family is ideal for investigating the mechanisms of evolutionary metabolic diversification. We developed methods to structurally analyze acylhexose mixtures by 2D NMR, which led to the insight that the Old World species black nightshade (Solanum nigrum) accumulates acylglucoses and acylinositols in the same tissue. Detailed in vitro biochemistry, cross-validated by in vivo virus-induced gene silencing, revealed two unique features of the four-step acylglucose biosynthetic pathway: A trichome-expressed, neofunctionalized invertase-like enzyme, SnASFF1, converts BAHD-produced acylsucroses to acylglucoses, which, in turn, are substrates for the acylglucose acyltransferase, SnAGAT1. This biosynthetic pathway evolved independently from that recently described in the wild tomato Solanum pennellii, reinforcing that acylsugar biosynthesis is evolutionarily dynamic with independent examples of primary metabolic enzyme cooption and additional variation in BAHD acyltransferases.
Collapse
Affiliation(s)
- Yann-Ru Lou
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Thilani M. Anthony
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Paul D. Fiesel
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | | | | | - A. Daniel Jones
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Robert L. Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| |
Collapse
|
13
|
Wang L, Chen K, Zhang M, Ye M, Qiao X. Catalytic function, mechanism, and application of plant acyltransferases. Crit Rev Biotechnol 2021; 42:125-144. [PMID: 34151663 DOI: 10.1080/07388551.2021.1931015] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Acyltransferases (ATs) are important tailoring enzymes that contribute to the diversity of natural products. They catalyze the transfer of acyl groups to the skeleton, which improves the lipid solubility, stability, and pharmacological activity of natural compounds. In recent years, a number of ATs have been isolated from plants. In this review, we have summarized 141 biochemically characterized ATs during the period July 1997 to October 2020, including their function, heterologous expression systems, and catalytic mechanisms. Their catalytic performance and application potential has been further discussed.
Collapse
Affiliation(s)
- Linlin Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Kuan Chen
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Meng Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Min Ye
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Xue Qiao
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| |
Collapse
|
14
|
Xu Y, Tie W, Yan Y, Xu B, Liu J, Li M, Yang J, Zeng J, Hu W, Jin Z. Identification and expression of the BAHD family during development, ripening, and stress response in banana. Mol Biol Rep 2021; 48:1127-1138. [PMID: 33492573 DOI: 10.1007/s11033-020-06132-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/24/2020] [Indexed: 01/10/2023]
Abstract
The BAHD family is involved in different biological roles in plants, including secondary metabolite synthesis, improving abiotic/biotic stress resistance, and influencing fruit quality. However, the knowledge about BAHD in banana, an important fruit crop, is limited. In this study, 46 banana BAHD genes (MaBAHDs) were identified and divided into four groups according to phylogenetic analysis. Most of the MaBAHD genes in the same group presented similar conserved motifs and genetic structures. MaBAHD genes have similar expression patterns in two banana varieties, and more genes showed high expressions in the roots. The comprehensive MaBAHD gene expression patterns obtained from two varieties of banana showed valuable information regarding their participation in fruit development, ripening, and response to abiotic/biotic stresses, suggesting that they play key roles in these processes. The systematic analysis of MaBAHD genes offered basic insight for further gene functional assays and potential applications in genetically improving banana cultivars.
Collapse
Affiliation(s)
- Yun Xu
- School of Life and Pharmaceutical Sciences, Hainan University, Haikou, China
| | - Weiwei Tie
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Yan Yan
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Biyu Xu
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Juhua Liu
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Meiying Li
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Jinghao Yang
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Jian Zeng
- Henry Fok School of Biology and Agriculture, Shaoguan University, Shaoguan, China.
| | - Wei Hu
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
| | - Zhiqiang Jin
- Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
| |
Collapse
|
15
|
An Integrated Analytical Approach Reveals Trichome Acylsugar Metabolite Diversity in the Wild Tomato Solanum pennellii. Metabolites 2020; 10:metabo10100401. [PMID: 33050231 PMCID: PMC7599763 DOI: 10.3390/metabo10100401] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/29/2020] [Accepted: 10/03/2020] [Indexed: 12/12/2022] Open
Abstract
Acylsugars constitute an abundant class of pest- and pathogen-protective Solanaceae family plant-specialized metabolites produced in secretory glandular trichomes. Solanum pennellii produces copious triacylated sucrose and glucose esters, and the core biosynthetic pathway producing these compounds was previously characterized. We performed untargeted metabolomic analysis of S. pennellii surface metabolites from accessions spanning the species range, which indicated geographic trends in the acylsugar profile and revealed two compound classes previously undescribed from this species, tetraacylglucoses and flavonoid aglycones. A combination of ultrahigh-performance liquid chromatography–high resolution mass spectrometry (UHPLC–HR-MS) and NMR spectroscopy identified variations in the number, length, and branching pattern of acyl chains, and the proportion of sugar cores in acylsugars among accessions. The new dimensions of acylsugar variation revealed by this analysis further indicate variation in the biosynthetic and degradative pathways responsible for acylsugar accumulation. These findings provide a starting point for deeper investigation of acylsugar biosynthesis, an understanding of which can be exploited through crop breeding or metabolic engineering strategies to improve the endogenous defenses of crop plants.
Collapse
|
16
|
Oshikiri H, Watanabe B, Yamamoto H, Yazaki K, Takanashi K. Two BAHD Acyltransferases Catalyze the Last Step in the Shikonin/Alkannin Biosynthetic Pathway. PLANT PHYSIOLOGY 2020; 184:753-761. [PMID: 32727911 PMCID: PMC7536692 DOI: 10.1104/pp.20.00207] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 07/24/2020] [Indexed: 05/28/2023]
Abstract
Several Boraginaceae plants produce biologically active red naphthoquinone pigments, derivatives of the enantiomers shikonin and alkannin, which vary in acyl groups on their side chains. Compositions of shikonin/alkannin derivatives vary in plant species, but the mechanisms generating the diversity of shikonin/alkannin derivatives are largely unknown. This study describes the identification and characterization of two BAHD acyltransferases, shikonin O-acyltransferase (LeSAT1) and alkannin O-acyltransferase (LeAAT1), from Lithospermum erythrorhizon, a medicinal plant in the family Boraginaceae that primarily produces the shikonin/alkannin derivatives acetylshikonin and β-hydroxyisovalerylshikonin. Enzyme assays using Escherichia coli showed that the acylation activity of LeSAT1 was specific to shikonin, whereas the acylation activity of LeAAT1 was specific to alkannin. Both enzymes recognized acetyl-CoA, isobutyryl-CoA, and isovaleryl-CoA as acyl donors to produce their corresponding shikonin/alkannin derivatives, with both enzymes showing the highest activity for acetyl-CoA. These findings were consistent with the composition of shikonin/alkannin derivatives in intact L erythrorhizon plants and cell cultures. Genes encoding both enzymes were preferentially expressed in the roots and cell cultures in the dark in pigment production medium M9, conditions associated with shikonin/alkannin production. These results indicated that LeSAT1 and LeAAT1 are enantiomer-specific acyltransferases that generate various shikonin/alkannin derivatives.
Collapse
Affiliation(s)
- Haruka Oshikiri
- Department of Biology, Faculty of Science, Shinshu University, Nagano 390-8621, Japan
| | - Bunta Watanabe
- Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan
| | - Hirobumi Yamamoto
- Department of Applied Biology, Faculty of Life Sciences, Toyo University, Gunma 374-0193, Japan
| | - Kazufumi Yazaki
- Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto 611-0011, Japan
| | - Kojiro Takanashi
- Department of Biology, Faculty of Science, Shinshu University, Nagano 390-8621, Japan
| |
Collapse
|
17
|
Nakashima T, Nambu Y, Inoue Y, Masimbula R, Matsuura H. Pennelliisides A-C, 2,3,4-Trisubstituted Acyl Glucoses Isolated from Solanum pennellii. JOURNAL OF NATURAL PRODUCTS 2020; 83:2337-2346. [PMID: 32803973 DOI: 10.1021/acs.jnatprod.9b01234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Solanum species accumulate a variety of secondary metabolites in their trichomes, and it is well known that acyl sugars are specialized metabolites secreted by the trichomes. However, very few reports provide detailed information on the chemical structure of polyacylated glucose derivatives, due to the α and β isomerization that can occur at the C-1 position. In this study, a strategy was established to isolate polyacylated glucose derivatives. According to the developed strategy, hydroxy groups were derivatized to a benzyloxy group using TriBOT. After isolation of the compounds in pure form and deprotection of the benzyloxy group, the chemical structures of pennelliisides A-C were determined as 2,3,4-O-triisobutyryl-d-glucose, 3-O-(8-methylnonanoyl)-2,4-O-diisobutyryl-d-glucose, and 3-O-decanoyl-2,4-O-diisobutyryl-d-glucose, respectively. Structural elucidation was performed using spectroscopic techniques, including 1D and 2D NMR, FD-MS, and GC-MS. It was also found that the fatty acid moiety contributes to the allelopathic properties of the isolated compounds.
Collapse
Affiliation(s)
- Tenki Nakashima
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Yurika Nambu
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Yutaka Inoue
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Rishni Masimbula
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Hideyuki Matsuura
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| |
Collapse
|
18
|
Chang AX, Chen B, Yang AG, Hu RS, Feng QF, Chen M, Yang XN, Luo CG, Li YY, Wang YY. The trichome-specific acetolactate synthase NtALS1 gene, is involved in acylsugar biosynthesis in tobacco (Nicotiana tabacum L.). PLANTA 2020; 252:13. [PMID: 32621079 DOI: 10.1007/s00425-020-03418-x] [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: 04/08/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
MAIN CONCLUSION NtALS1 is specifically expressed in glandular trichomes, and can improve the content of acylsugars in tobacco. ABTRACT The glandular trichomes of many species in the Solanaceae family play an important role in plant defense. These epidermal outgrowths exhibit specialized secondary metabolism, including the production of structurally diverse acylsugars that function in defense against insects and have substantial developmental potential for commercial uses. However, our current understanding of genes involved in acyl chain biosynthesis of acylsugars remains poor in tobacco. In this study, we identified three acetolactate synthase (ALS) genes in tobacco through homology-based gene prediction using Arabidopsis ALS. Quantitative real-time PCR (qRT-PCR) and tissue distribution analyses suggested that NtALS1 was highly expressed in the tips of glandular trichomes. Subcellular localization analysis showed that the NtALS1 localized to the chloroplast. Moreover, in the wild-type K326 variety background, we generated two ntals1 loss-of-function mutants using the CRISPR-Cas9 system. Acylsugars contents in the two ntals1 mutants were significantly lower than those in the wild type. Through phylogenetic tree analysis, we also identified NtALS1 orthologs that may be involved in acylsugar biosynthesis in other Solanaceae species. Taken together, these findings indicate a functional role for NtALS1 in acylsugar biosynthesis in tobacco.
Collapse
Affiliation(s)
- Ai-Xia Chang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Biao Chen
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Ai-Guo Yang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Ri-Sheng Hu
- Hunan Tobacco Research Institute, Changsha, China
| | - Quan-Fu Feng
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Ming Chen
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Xiao-Ning Yang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Cheng-Gang Luo
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Yang-Yang Li
- Hunan Tobacco Research Institute, Changsha, China.
| | - Yuan-Ying Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China.
| |
Collapse
|
19
|
Fan P, Wang P, Lou YR, Leong BJ, Moore BM, Schenck CA, Combs R, Cao P, Brandizzi F, Shiu SH, Last RL. Evolution of a plant gene cluster in Solanaceae and emergence of metabolic diversity. eLife 2020; 9:e56717. [PMID: 32613943 PMCID: PMC7386920 DOI: 10.7554/elife.56717] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 07/01/2020] [Indexed: 12/15/2022] Open
Abstract
Plants produce phylogenetically and spatially restricted, as well as structurally diverse specialized metabolites via multistep metabolic pathways. Hallmarks of specialized metabolic evolution include enzymatic promiscuity and recruitment of primary metabolic enzymes and examples of genomic clustering of pathway genes. Solanaceae glandular trichomes produce defensive acylsugars, with sidechains that vary in length across the family. We describe a tomato gene cluster on chromosome 7 involved in medium chain acylsugar accumulation due to trichome specific acyl-CoA synthetase and enoyl-CoA hydratase genes. This cluster co-localizes with a tomato steroidal alkaloid gene cluster and is syntenic to a chromosome 12 region containing another acylsugar pathway gene. We reconstructed the evolutionary events leading to this gene cluster and found that its phylogenetic distribution correlates with medium chain acylsugar accumulation across the Solanaceae. This work reveals insights into the dynamics behind gene cluster evolution and cell-type specific metabolite diversity.
Collapse
Affiliation(s)
- Pengxiang Fan
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast LansingUnited States
| | - Peipei Wang
- Department of Plant Biology, Michigan State UniversityEast LansingUnited States
| | - Yann-Ru Lou
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast LansingUnited States
| | - Bryan J Leong
- Department of Plant Biology, Michigan State UniversityEast LansingUnited States
| | - Bethany M Moore
- Department of Plant Biology, Michigan State UniversityEast LansingUnited States
- University of WisconsinMadisonUnited States
| | - Craig A Schenck
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast LansingUnited States
| | - Rachel Combs
- Division of Biological Sciences, University of MissouriColumbusUnited States
| | - Pengfei Cao
- Department of Plant Biology, Michigan State UniversityEast LansingUnited States
- MSU-DOE Plant Research Laboratory, Michigan State UniversityEast LansingUnited States
| | - Federica Brandizzi
- Department of Plant Biology, Michigan State UniversityEast LansingUnited States
- MSU-DOE Plant Research Laboratory, Michigan State UniversityEast LansingUnited States
| | - Shin-Han Shiu
- Department of Plant Biology, Michigan State UniversityEast LansingUnited States
- Department of Computational Mathematics, Science, and Engineering, Michigan State UniversityEast LansingUnited States
| | - Robert L Last
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast LansingUnited States
- Department of Plant Biology, Michigan State UniversityEast LansingUnited States
| |
Collapse
|
20
|
Mihaylova-Kroumova AB, Artiouchine I, Korenkov VD, Wagner GJ. Patterns of inheritance of acylsugar acyl groups in selected interspecific hybrids of genus Nicotiana. JOURNAL OF PLANT RESEARCH 2020; 133:509-523. [PMID: 32277383 DOI: 10.1007/s10265-020-01188-x] [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: 12/05/2019] [Accepted: 04/02/2020] [Indexed: 05/26/2023]
Abstract
Glandular trichomes on the surface of Solanaceae species produce acyl sugars that are species-, and cultivar-specific. Acyl sugars are known to possess insecticidal, antibiotic, and hormone-like properties, and as such have great potential as a class of naturally occurring pesticides and antibiotics. The objective of this work was to analyze the acyl composition of acyl sugars in the leaf trichome exudate from selected Nicotiana species and to follow the inheritance of acyl content in their hybrids. Trichome exudates were collected, and the acyl profiles of acyl sugars were identified via GC-MS. The variations in acyl group inheritance in the hybrids (a single parent resemblance, missing, complementary, and novel groups) matched the patterns described in the literature for a variety of secondary metabolites. However, we did not find a complementation of major parental acyl groups. Instead, in some hybrids we observed a dynamic change in the proportions of acyl groups, distinguishing the acyl group profiles as novel. We observed paternal (i.e. N. tabacum cv. Turkish Samsun × N. benthamiana hybrids) and maternal (i.e. N. tabacum cv. Samsun-nn × N. otophora) inheritance patterns, novel acyl profiles (N. excelsior hybrids), and missing acyl groups (N. excelsiana). Selective inheritance of some acyl groups in the hybrids of N. benthamiana (4- and 5-methylheptanoic isomers) or N. alata (octanoate) was found. Suggestions are given to explain certain patterns of inheritance. The data presented here contribute to the body of knowledge about the effect of interspecific hybridization on the secondary metabolites by including acylsugar acyl groups that have not been studied previously.
Collapse
Affiliation(s)
- Antoaneta B Mihaylova-Kroumova
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA.
| | - Ivan Artiouchine
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA
| | - Victor D Korenkov
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA
| | - George J Wagner
- Kentucky Tobacco Research and Development Center, College of Agriculture, University of Kentucky, 1401 University Dr., Lexington, KY, 40546-0236, USA
| |
Collapse
|
21
|
Leong BJ, Hurney SM, Fiesel PD, Moghe GD, Jones AD, Last RL. Specialized Metabolism in a Nonmodel Nightshade: Trichome Acylinositol Biosynthesis. PLANT PHYSIOLOGY 2020; 183:915-924. [PMID: 32354879 PMCID: PMC7333698 DOI: 10.1104/pp.20.00276] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/15/2020] [Indexed: 05/13/2023]
Abstract
Plants make many biologically active, specialized metabolites, which vary in structure, biosynthesis, and the processes they influence. An increasing number of these compounds are documented to protect plants from insects, pathogens, or herbivores or to mediate interactions with beneficial organisms, including pollinators and nitrogen-fixing microbes. Acylsugars, one class of protective compounds, are made in glandular trichomes of plants across the Solanaceae family. While most described acylsugars are acylsucroses, published examples also include acylsugars with hexose cores. The South American fruit crop naranjilla (lulo; Solanum quitoense) produces acylsugars containing a myoinositol core. We identified an enzyme that acetylates triacylinositols, a function homologous to the last step in the acylsucrose biosynthetic pathway of tomato (Solanum lycopersicum). Our analysis reveals parallels between S. lycopersicum acylsucrose and S. quitoense acylinositol biosynthesis, suggesting a common evolutionary origin.
Collapse
Affiliation(s)
- Bryan J Leong
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Steven M Hurney
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824
| | - Paul D Fiesel
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Gaurav D Moghe
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - A Daniel Jones
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Robert L Last
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
22
|
Fan P, Leong BJ, Last RL. Tip of the trichome: evolution of acylsugar metabolic diversity in Solanaceae. CURRENT OPINION IN PLANT BIOLOGY 2019; 49:8-16. [PMID: 31009840 PMCID: PMC6688940 DOI: 10.1016/j.pbi.2019.03.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/11/2019] [Accepted: 03/15/2019] [Indexed: 05/11/2023]
Abstract
Acylsugars are insecticidal plant specialized metabolites produced in the Solanaceae (nightshade family). Despite having simple constituents, these compounds are unusually structurally diverse. Their structural variations in phylogenetically closely related species enable comparative biochemical approaches to understand acylsugar biosynthesis and pathway diversification. Thus far, varied enzyme classes contributing to their synthesis were characterized in cultivated and wild tomatoes, including from core metabolism - isopropylmalate synthase (Leu) and invertase (carbon) - and a group of evolutionarily related BAHD acyltransferases known as acylsucrose acyltransferases. Gene duplication and neofunctionalization of these enzymes drove acylsugar diversification both within and beyond tomato. The broad set of evolutionary mechanisms underlying acylsugar diversity in Solanaceae make this metabolic network an exemplar for detailed understanding of the evolution of metabolic form and function.
Collapse
Affiliation(s)
- Pengxiang Fan
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Bryan J Leong
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Robert L Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
| |
Collapse
|
23
|
Leong BJ, Lybrand DB, Lou YR, Fan P, Schilmiller AL, Last RL. Evolution of metabolic novelty: A trichome-expressed invertase creates specialized metabolic diversity in wild tomato. SCIENCE ADVANCES 2019; 5:eaaw3754. [PMID: 31032420 PMCID: PMC6482016 DOI: 10.1126/sciadv.aaw3754] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/06/2019] [Indexed: 05/19/2023]
Abstract
Plants produce a myriad of taxonomically restricted specialized metabolites. This diversity-and our ability to correlate genotype with phenotype-makes the evolution of these ecologically and medicinally important compounds interesting and experimentally tractable. Trichomes of tomato and other nightshade family plants produce structurally diverse protective compounds termed acylsugars. While cultivated tomato (Solanum lycopersicum) strictly accumulates acylsucroses, the South American wild relative Solanum pennellii produces copious amounts of acylglucoses. Genetic, transgenic, and biochemical dissection of the S. pennellii acylglucose biosynthetic pathway identified a trichome gland cell-expressed invertase-like enzyme that hydrolyzes acylsucroses (Sopen03g040490). This enzyme acts on the pyranose ring-acylated acylsucroses found in the wild tomato but not on the furanose ring-decorated acylsucroses of cultivated tomato. These results show that modification of the core acylsucrose biosynthetic pathway leading to loss of furanose ring acylation set the stage for co-option of a general metabolic enzyme to produce a new class of protective compounds.
Collapse
Affiliation(s)
- Bryan J. Leong
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Daniel B. Lybrand
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Yann-Ru Lou
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Pengxiang Fan
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Anthony L. Schilmiller
- Mass Spectrometry and Metabolomics Core, Michigan State University, East Lansing, MI, USA
| | - Robert L. Last
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
- Corresponding author.
| |
Collapse
|
24
|
Liu Y, Jing SX, Luo SH, Li SH. Non-volatile natural products in plant glandular trichomes: chemistry, biological activities and biosynthesis. Nat Prod Rep 2019; 36:626-665. [PMID: 30468448 DOI: 10.1039/c8np00077h] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The investigation methods, chemistry, bioactivities, and biosynthesis of non-volatile natural products involving 489 compounds in plant glandular trichomes are reviewed.
Collapse
Affiliation(s)
- Yan Liu
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- P. R. China
| | - Shu-Xi Jing
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- P. R. China
| | - Shi-Hong Luo
- College of Bioscience and Biotechnology
- Shenyang Agricultural University
- Shenyang
- P. R. China
| | - Sheng-Hong Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China
- Kunming Institute of Botany
- Chinese Academy of Sciences
- Kunming 650201
- P. R. China
| |
Collapse
|
25
|
Evolution of a flipped pathway creates metabolic innovation in tomato trichomes through BAHD enzyme promiscuity. Nat Commun 2017; 8:2080. [PMID: 29234041 PMCID: PMC5727100 DOI: 10.1038/s41467-017-02045-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 11/03/2017] [Indexed: 01/29/2023] Open
Abstract
Plants produce hundreds of thousands of structurally diverse specialized metabolites via multistep biosynthetic networks, including compounds of ecological and therapeutic importance. These pathways are restricted to specific plant groups, and are excellent systems for understanding metabolic evolution. Tomato and other plants in the nightshade family synthesize protective acylated sugars in the tip cells of glandular trichomes on stems and leaves. We describe a metabolic innovation in wild tomato species that contributes to acylsucrose structural diversity. A small number of amino acid changes in two acylsucrose acyltransferases alter their acyl acceptor preferences, resulting in reversal of their order of reaction and increased product diversity. This study demonstrates how small numbers of amino acid changes in multiple pathway enzymes can lead to diversification of specialized metabolites in plants. It also highlights the power of a combined genetic, genomic and in vitro biochemical approach to identify the evolutionary mechanisms leading to metabolic novelty. Plants produce large numbers of structurally diverse metabolites through multistep pathways that often use the same precursors. Here the authors utilize the pathway leading to the production of acylated sucroses in the tomato plant to illustrate how metabolite diversity can arise through biochemical pathway evolution.
Collapse
|
26
|
Moghe GD, Leong BJ, Hurney SM, Daniel Jones A, Last RL. Evolutionary routes to biochemical innovation revealed by integrative analysis of a plant-defense related specialized metabolic pathway. eLife 2017; 6:28468. [PMID: 28853706 PMCID: PMC5595436 DOI: 10.7554/elife.28468] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/25/2017] [Indexed: 12/22/2022] Open
Abstract
The diversity of life on Earth is a result of continual innovations in molecular networks influencing morphology and physiology. Plant specialized metabolism produces hundreds of thousands of compounds, offering striking examples of these innovations. To understand how this novelty is generated, we investigated the evolution of the Solanaceae family-specific, trichome-localized acylsugar biosynthetic pathway using a combination of mass spectrometry, RNA-seq, enzyme assays, RNAi and phylogenomics in different non-model species. Our results reveal hundreds of acylsugars produced across the Solanaceae family and even within a single plant, built on simple sugar cores. The relatively short biosynthetic pathway experienced repeated cycles of innovation over the last 100 million years that include gene duplication and divergence, gene loss, evolution of substrate preference and promiscuity. This study provides mechanistic insights into the emergence of plant chemical novelty, and offers a template for investigating the ~300,000 non-model plant species that remain underexplored. There are about 300,000 species of plant on Earth, which together produce over a million different small molecules called metabolites. Plants use many of these molecules to grow, to communicate with each other or to defend themselves against pests and disease. Humans have co-opted many of the same molecules as well; for example, some are important nutrients while others are active ingredients in medicines. Many plant metabolites are found in almost all plants, but hundreds of thousands of them are more specialized and only found in small groups of related plant species. These specialized metabolites have a wide variety of structures, and are made by different enzymes working together to carry out a series of biochemical reactions. Acylsugars are an example of a group of specialized metabolites with particularly diverse structures. These small molecules are restricted to plants in the Solanaceae family, which includes tomato and tobacco plants. Moghe et al. have now focused on acylsugars to better understand how plants produce the large diversity of chemical structures found in specialized metabolites, and how these processes have evolved over time. An analysis of over 35 plant species from across the Solanaceae family revealed hundreds of acylsugars, with some plants accumulating 300 or more different types of these specialized metabolites. Moghe et al. then looked at the enzymes that make acylsugars from a poorly studied flowering plant called Salpiglossis sinuata, partly because it produces a large diversity of these small molecules and partly because it sits in a unique position in the Solanaceae family tree. The activities of the enzymes were confirmed both in test tubes and in plants. This suggested that many of the enzymes were “promiscuous”, meaning that they could likely use a variety of molecules as starting points for their chemical reactions. This finding could help to explain how this plant species can make such a wide variety of acylsugars. Moghe et al. also discovered that many of the enzymes that make acylsugars are encoded by genes that were originally copies of other genes and that have subsequently evolved new activities. Plant scientists and plant breeders value tomato plants that produce acylsugars because these natural chemicals protect against pests like whiteflies and spider mites. A clearer understanding of the diversity of acylsugars in the Solanaceae family, as well as the enzymes that make these specialized metabolites, could help efforts to breed crops that are more resistant to pests. Some of the enzymes related to those involved in acylsugar production could also help to make chemicals with pharmaceutical value. These new findings might also eventually lead to innovative ways to produce these chemicals on a large scale.
Collapse
Affiliation(s)
- Gaurav D Moghe
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States
| | - Bryan J Leong
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States.,Department of Plant Biology, Michigan State University, East Lansing, United States
| | - Steven M Hurney
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States.,Department of Chemistry, Michigan State University, East Lansing, United States
| | - A Daniel Jones
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States.,Department of Chemistry, Michigan State University, East Lansing, United States
| | - Robert L Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States.,Department of Plant Biology, Michigan State University, East Lansing, United States
| |
Collapse
|