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Lu J, Yan S, Xue Z. Biosynthesis and functions of triterpenoids in cereals. J Adv Res 2024:S2090-1232(24)00211-X. [PMID: 38788922 DOI: 10.1016/j.jare.2024.05.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/03/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024] Open
Abstract
BACKGROUND Triterpenoids are versatile secondary metabolites with a diverse array of physiological activities, possessing valuable pharmacological effects and influencing the growth and development of plants. As more triterpenoids in cereals are unearthed and characterized, their biological roles in plant growth and development are gaining recognition. AIM OF THE REVIEW This review provides an overview of the structures, biosynthetic pathways, and diverse biological functions of triterpenoids identified in cereals. Our goal is to establish a basis for further exploration of triterpenoids with novel structures and functional activities in cereals, and to facilitate the potential application of triterpenoids in grain breeding, thus accelerating the development of superior grain varieties. KEY SCIENTIFIC CONCEPTS OF THE REVIEW This review consolidates information on various triterpenoid skeletons and derivatives found in cereals, and summarizes the pivotal enzyme genes involved, including oxidosqualene cyclase (OSC) and other triterpenoid modifying enzymes like cytochrome P450, glycosyltransferase, and acyltransferase. Triterpenoid-modifying enzymes exhibit specificity towards catalytic sites within triterpenoid skeletons, generating a diverse array of functional triterpenoid derivatives. Furthermore, triterpenoids have been shown to significantly impact the nutritional value, yield, disease resistance, and stress response of cereals.
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Affiliation(s)
- Jiaojiao Lu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin, China; Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, China
| | - Shan Yan
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin, China; Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, China
| | - Zheyong Xue
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin, China; Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, China; State Key Laboratory of Rice Biology and Breeding, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou 310006, China.
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Huang Y, Liu H, Zhou Y, Lu Z, Pu Y, Zhang H. Cloning and functional characterization of the oxidative squalene cyclase gene in the deep-sea holothurian Chiridota sp. Gene 2024; 894:147971. [PMID: 37949417 DOI: 10.1016/j.gene.2023.147971] [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: 05/08/2023] [Revised: 09/10/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023]
Abstract
Saponins derived from holothurians have high potential medicinal value. However, the de novo synthesis of the derivatization of triterpenes is still unclear. Oxidative squalene cyclase (OSC) can catalyze 2,3-Oxidosqualene into diverse products that serve as important precursors for triterpene synthesis. However, the function of theOSCgene in Chiridotasp. hasnot been elucidated. In this study, an OSCgenederived from the deep-sea holothurianChiridota sp. was cloned and characterized functionally in a yeast system. The open reading frame of the OSC gene was 2086 bp, which encoded 695 amino acids. The Chiridota sp. OSC gene has a similarity of 66.89 % to the OSC of other holothurian species and 63.51 % to that of Acanthaster planci. The phylogenetic tree showed that the echinozoan OSCsclustered together, and then they formeda sister group to fungi and plant homologs. Chiridota sp. OSC catalyzed 2,3-Oxidosqualene into parkeol.Under high pressure, the relative enzymatic activity and stability of cyclase inChiridota sp. was higher than that in the shallow-sea holothurianStichopus horrens. The newly cloned OSC of Chiridota sp.provideskey information for the interpretation of the saponin synthesis pathway in deep-sea holothurians.
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Affiliation(s)
- Yanan Huang
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Helu Liu
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
| | - Yang Zhou
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
| | - Zaiqing Lu
- Ocean University of China, Qingdao 266100, China
| | - Yujin Pu
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haibin Zhang
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China.
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Liu X, Xu Y, Di J, Liu A, Jiang J. The triterpenoid saponin content difference is associated with the two type oxidosqualene cyclase gene copy numbers of Pulsatilla chinensis and Pulsatilla cernua. FRONTIERS IN PLANT SCIENCE 2023; 14:1144738. [PMID: 36909385 PMCID: PMC9995806 DOI: 10.3389/fpls.2023.1144738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Pulsatilla chinensis is an important medicinal herb, its dried radix is used to treat the inflammation since ancient China. Triterpenoid saponins are proved to be the main active compounds of Pulsatilla genus. The triterpenoid saponin contents vary widely in different Pulsatilla species. But no enzyme involved in the triterpenoid saponin biosynthetic pathway was identified in Pulsitilla genus. This seriously limits the explanation of the triterpene content difference of Pulsatilla species. In this article, we obtained two oxidosqualene cyclase (OSC) genes from P. chinensis and P. cernua by touchdown PCR and anchored PCR. These two OSCs converted 2,3-oxidosqualene into different triterpenoids. The OSC from P. cernua is a monofunctional enzyme for β-amyrin synthesis, while the OSC from P. chinensis is a multifunctional enzyme for lupeol and β-amyrin synthesis, and the lupeol is the main product. Then we identified the 260th amino acid residue was the key site for the product difference by gene fusion and site-directed mutant technology. When the 260th amino acid residue was tryptophan (W260) and phenylalanine (F260), the main catalysate was β-amyrin and lupeol, respectively. Then we found that the expression of these two genes was strongly correlated with the lupeol-type and β-amyrin-type triterpenoid contents in P. cernua and P. chinensis. Finally, we found the gene copy number difference of these two genotypes leaded to the triterpenoid diversity in P. cernua and P. chinensis. This study provides useful information for the molecular breeding and quality improvement of P. chinensis and a molecular marker to identify the P. chinensis decoction pieces.
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Affiliation(s)
| | | | | | - An Liu
- *Correspondence: Jinzhu Jiang, ; An Liu,
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Wang J, Guo Y, Yin X, Wang X, Qi X, Xue Z. Diverse triterpene skeletons are derived from the expansion and divergent evolution of 2,3-oxidosqualene cyclases in plants. Crit Rev Biochem Mol Biol 2021; 57:113-132. [PMID: 34601979 DOI: 10.1080/10409238.2021.1979458] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Triterpenoids are one of the largest groups of secondary metabolites and exhibit diverse structures, which are derived from C30 skeletons that are biosynthesized via the isoprenoid pathway by cyclization of 2,3-oxidosqualene. Triterpenoids have a wide range of biological activities, and are used in functional foods, drugs, and as industrial materials. Due to the low content levels in their native plants and limited feasibility and efficiency of chemical synthesis, heterologous biosynthesis of triterpenoids is the most promising strategy. Herein, we classified 121 triterpene alcohols/ketones according to their conformation and ring numbers, among which 51 skeletons have been experimentally characterized as the products of oxidosqualene cyclases (OSCs). Interestingly, 24 skeletons that have not been reported from nature source were generated by OSCs in heterologous expression. Comprehensive evolutionary analysis of the identified 152 OSCs from 75 species in 25 plant orders show that several pentacyclic triterpene synthases repeatedly originated in multiple plant lineages. Comparative analysis of OSC catalytic reaction revealed that stabilization of intermediate cations, steric hindrance, and conformation of active center amino acid residues are primary factors affecting triterpene formation. Optimization of OSC could be achieved by changing of side-chain orientations of key residues. Recently, methods, such as rationally design of pathways, regulation of metabolic flow, compartmentalization engineering, etc., were introduced in improving chassis for the biosynthesis of triterpenoids. We expect that extensive study of natural variation of large number of OSCs and catalytical mechanism will provide basis for production of high level of triterpenoids by application of synthetic biology strategies.
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Affiliation(s)
- Jing Wang
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China.,Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, PR China
| | - Yanhong Guo
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China
| | - Xue Yin
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China
| | - Xiaoning Wang
- Department of Natural Product Chemistry, Key Laboratory of Chemical Biology, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Xiaoquan Qi
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, PR China
| | - Zheyong Xue
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, PR China.,Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization, Northeast Forestry University, Harbin, PR China
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Chen K, Zhang M, Ye M, Qiao X. Site-directed mutagenesis and substrate compatibility to reveal the structure-function relationships of plant oxidosqualene cyclases. Nat Prod Rep 2021; 38:2261-2275. [PMID: 33988197 DOI: 10.1039/d1np00015b] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: up to May 2020Oxidosqualene cyclases (OSCs) catalyze one of the most complex polycyclization reactions in nature, using the linear 2,3-oxidosqualene to generate an array of triterpene skeletons in plants. Despite the structural diversity of the products, the protein sequences of plant OSCs are highly conserved, where a few key amino acids could govern the product selectivity. Due to the absence of crystal structures, site-directed mutagenesis and substrate structural modification become key approaches to understand the cyclization mechanism. In this review, 98 mutation sites in 25 plant OSCs have been summarized, and the conserved key residues have been identified by sequence alignment. Structure-function relationships are further discussed. Meanwhile, the substrate selectivity has been summarized to probe the active site cavity of plant OSCs. A total of 77 references are included.
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Affiliation(s)
- Kuan Chen
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
| | - Meng Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
| | - Min Ye
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
| | - Xue Qiao
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
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