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Yuan F, Yan S, Zhao J. Elucidating the Phytochemical Landscape of Leaves, Stems, and Tubers of Codonopsis convolvulacea through Integrated Metabolomics. Molecules 2024; 29:3193. [PMID: 38999145 DOI: 10.3390/molecules29133193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/22/2024] [Accepted: 07/01/2024] [Indexed: 07/14/2024] Open
Abstract
Codonopsis convolvulacea is a highly valued Chinese medicinal plant containing diverse bioactive compounds. While roots/tubers have been the main medicinal parts used in practice, leaves and stems may also harbor valuable phytochemicals. However, research comparing volatiles across tissues is lacking. This study performed metabolomic profiling of leaves, stems, and tubers of C. convolvulacea to elucidate tissue-specific accumulation patterns of volatile metabolites. Ultra-high performance liquid chromatography-tandem mass spectrometry identified 302 compounds, belonging to 14 classes. Multivariate analysis clearly differentiated the metabolic profiles of the three tissues. Numerous differentially accumulated metabolites (DAMs) were detected, especially terpenoids and esters. The leaves contained more terpenoids, ester, and alcohol. The stems accumulated higher levels of terpenoids, heterocyclics, and alkaloids with pharmaceutical potential. The tubers were enriched with carbohydrates like sugars and starch, befitting their storage role, but still retained reasonable amounts of valuable volatiles. The characterization of tissue-specific metabolic signatures provides a foundation for the selective utilization of C. convolvulacea parts. Key metabolites identified include niacinamide, p-cymene, tridecanal, benzeneacetic acid, benzene, and carveol. Leaves, stems, and tubers could be targeted for antioxidants, drug development, and tonics/nutraceuticals, respectively. The metabolomic insights can also guide breeding strategies to enhance the bioactive compound content in specific tissues. This study demonstrates the value of tissue-specific metabolite profiling for informing the phytochemical exploitation and genetic improvement of medicinal plants.
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Affiliation(s)
- Fang Yuan
- Key Laboratory of Biological Resource and Ecological Environment of Chinese Education Ministry, College of Life Sciences, Sichuan University, Chengdu 610065, China
- Key Laboratory of Tibetan Medicine Resources Conservation and Utilization of Tibet Autonomous Region, Tibet Agriculture and Animal Husbandry University, Nyingchi 860000, China
| | - Shiying Yan
- Key Laboratory of Biological Resource and Ecological Environment of Chinese Education Ministry, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Jian Zhao
- Key Laboratory of Biological Resource and Ecological Environment of Chinese Education Ministry, College of Life Sciences, Sichuan University, Chengdu 610065, China
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Zannino L, Carelli M, Milanesi G, Croce AC, Biggiogera M, Confalonieri M. Histochemical and ultrastructural localization of triterpene saponins in Medicago truncatula. Microsc Res Tech 2024. [PMID: 38706034 DOI: 10.1002/jemt.24591] [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: 02/06/2024] [Revised: 03/26/2024] [Accepted: 04/20/2024] [Indexed: 05/07/2024]
Abstract
In the Medicago genus, saponins are complex mixtures of triterpene pentacyclic glycosides extensively studied for their different and economically relevant biological and pharmaceutical properties. This research is aimed at determining for the first time the tissue and cellular localization of triterpene saponins in vegetative organs of Medicago truncatula, a model plant species for legumes, by histochemistry and transmission electron microscopy. The results showed that saponins are present mainly in the palisade mesophyll layer of leaves, whereas in stems they are mostly located in the primary phloem and the subepidermal cells of cortical parenchyma. In root tissue, saponins occur in the secondary phloem region. Transmission electron microscopy revealed prominent saponin accumulation within the leaf and stem chloroplasts, while in the roots the saponins are found in the vesicular structures. Our results demonstrate the feasibility of using histochemistry and transmission electron microscopy to localize M. truncatula saponins at tissue and cellular levels and provide important information for further studies on biosynthesis and regulation of valuable bioactive saponins on agronomic relevant Medicago spp., such as alfalfa (Medicago sativa L.). RESEARCH HIGHLIGHTS: The Medicago genus represents a valuable rich source of saponins, one of the most interesting groups of secondary plant metabolites, which possess relevant biological and pharmacological properties. Plant tissue and cellular localization of saponins is of great importance to better understand their biological functions, biosynthetic pathway, and regulatory mechanisms. We elucidate the localization of saponins in Medicago truncatula with histochemical and transmission electron microscopy studies.
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Affiliation(s)
- Lorena Zannino
- Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratory of Cell Biology and Neurobiology, University of Pavia, Pavia, Italy
| | - Maria Carelli
- Council for Agricultural Research and Economics (CREA), Research Centre for Animal Production and Aquaculture (CREA-ZA), Lodi, Italy
| | - Gloria Milanesi
- Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratory of Cell Biology and Neurobiology, University of Pavia, Pavia, Italy
| | - Anna Cleta Croce
- Institute of Molecular Genetics, Italian National Research Council (CNR), c/o Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Marco Biggiogera
- Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratory of Cell Biology and Neurobiology, University of Pavia, Pavia, Italy
| | - Massimo Confalonieri
- Council for Agricultural Research and Economics (CREA), Research Centre for Animal Production and Aquaculture (CREA-ZA), Lodi, Italy
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Stanková J, Jurášek M, Hajdúch M, Džubák P. Terpenes and Terpenoids Conjugated with BODIPYs: An Overview of Biological and Chemical Properties. JOURNAL OF NATURAL PRODUCTS 2024; 87:1306-1319. [PMID: 38482846 PMCID: PMC11061839 DOI: 10.1021/acs.jnatprod.3c00961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 02/28/2024] [Accepted: 03/04/2024] [Indexed: 05/03/2024]
Abstract
Advancements in small-molecule research have created the need for sensitive techniques to accurately study biological processes in living systems. Fluorescent-labeled probes have become indispensable tools, particularly those that use boron-dipyrromethene (BODIPY) dyes. Terpenes and terpenoids are organic compounds found in nature that offer diverse biological activities, and BODIPY-based probes play a crucial role in studying these compounds. Monoterpene-BODIPY conjugates have exhibited potential for staining bacterial and fungal cells. Sesquiterpene-BODIPY derivatives have been used to study sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA), indicating their potential for drug development. Owing to their unique properties, diterpenes have been investigated using BODIPY conjugates to evaluate their mechanisms of action. Triterpene-BODIPY conjugates have been synthesized for biological studies, with different spacers affecting their cytotoxicity. Fluorescent probes, inspired by terpenoid-containing vitamins, have also been developed. Derivatives of tocopherol, coenzyme Q10, and vitamin K1 can provide insights into their oxidation-reduction abilities. All these probes have diverse applications, including the study of cell membranes to investigate immune responses and antioxidant properties. Further research in this field can help better understand and use terpenes and terpenoids in various biological contexts.
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Affiliation(s)
- Jarmila Stanková
- Institute
of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, 77900 Olomouc, Czech Republic
| | - Michal Jurášek
- Department
of Chemistry of Natural Compounds, University
of Chemistry and Technology Prague, 16628 Prague, Czech Republic
| | - Marián Hajdúch
- Institute
of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, 77900 Olomouc, Czech Republic
- Laboratory
of Experimental Medicine, Institute of Molecular and Translational
Medicine, University Hospital Olomouc, 77900 Olomouc, Czech Republic
| | - Petr Džubák
- Institute
of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, 77900 Olomouc, Czech Republic
- Laboratory
of Experimental Medicine, Institute of Molecular and Translational
Medicine, University Hospital Olomouc, 77900 Olomouc, Czech Republic
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Bouchnak I, Coulon D, Salis V, D’Andréa S, Bréhélin C. Lipid droplets are versatile organelles involved in plant development and plant response to environmental changes. FRONTIERS IN PLANT SCIENCE 2023; 14:1193905. [PMID: 37426978 PMCID: PMC10327486 DOI: 10.3389/fpls.2023.1193905] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/23/2023] [Indexed: 07/11/2023]
Abstract
Since decades plant lipid droplets (LDs) are described as storage organelles accumulated in seeds to provide energy for seedling growth after germination. Indeed, LDs are the site of accumulation for neutral lipids, predominantly triacylglycerols (TAGs), one of the most energy-dense molecules, and sterol esters. Such organelles are present in the whole plant kingdom, from microalgae to perennial trees, and can probably be found in all plant tissues. Several studies over the past decade have revealed that LDs are not merely simple energy storage compartments, but also dynamic structures involved in diverse cellular processes like membrane remodeling, regulation of energy homeostasis and stress responses. In this review, we aim to highlight the functions of LDs in plant development and response to environmental changes. In particular, we tackle the fate and roles of LDs during the plant post-stress recovery phase.
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Affiliation(s)
- Imen Bouchnak
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
| | - Denis Coulon
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
| | - Vincent Salis
- Université Paris-Saclay, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Sabine D’Andréa
- Université Paris-Saclay, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Claire Bréhélin
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
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Burciaga-Monge A, López-Tubau JM, Laibach N, Deng C, Ferrer A, Altabella T. Effects of impaired steryl ester biosynthesis on tomato growth and developmental processes. FRONTIERS IN PLANT SCIENCE 2022; 13:984100. [PMID: 36247562 PMCID: PMC9557751 DOI: 10.3389/fpls.2022.984100] [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: 07/01/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Steryl esters (SE) are stored in cytoplasmic lipid droplets and serve as a reservoir of sterols that helps to maintain free sterols (FS) homeostasis in cell membranes throughout plant growth and development, and provides the FS needed to meet the high demand of these key plasma membrane components during rapid plant organ growth and expansion. SE are also involved in the recycling of sterols and fatty acids released from membranes during plant tissues senescence. SE are synthesized by sterol acyltransferases, which catalyze the transfer of long-chain fatty acid groups to the hydroxyl group at C3 position of FS. Depending on the donor substrate, these enzymes are called acyl-CoA:sterol acyltransferases (ASAT), when the substrate is a long-chain acyl-CoA, and phospholipid:sterol acyltransferases (PSAT), which use a phospholipid as a donor substrate. We have recently identified and preliminary characterized the tomato (Solanum lycopersicum cv. Micro-Tom) SlASAT1 and SlPSAT1 enzymes. To gain further insight into the biological role of these enzymes and SE biosynthesis in tomato, we generated and characterized CRISPR/Cas9 single knock-out mutants lacking SlPSAT1 (slpsat1) and SlASAT1 (slasat1), as well as the double mutant slpsat1 x slasat1. Analysis of FS and SE profiles in seeds and leaves of the single and double mutants revealed a strong depletion of SE in slpsat1, that was even more pronounced in the slpsat1 x slasat1 mutant, while an increase of SE levels was observed in slasat1. Moreover, SlPSAT1 and SlASAT1 inactivation affected in different ways several important cellular and physiological processes, like leaf lipid bo1dies formation, seed germination speed, leaf senescence, and the plant size. Altogether, our results indicate that SlPSAT1 has a predominant role in tomato SE biosynthesis while SlASAT1 would mainly regulate the flux of the sterol pathway. It is also worth to mention that some of the metabolic and physiological responses in the tomato mutants lacking functional SlPSAT1 or SlASAT1 are different from those previously reported in Arabidopsis, being remarkable the synergistic effect of SlASAT1 inactivation in the absence of a functional SlPSAT1 on the early germination and premature senescence phenotypes.
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Affiliation(s)
- Alma Burciaga-Monge
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Joan Manel López-Tubau
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Natalie Laibach
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Cuiyun Deng
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Albert Ferrer
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Teresa Altabella
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
- Department of Biology, Healthcare and the Environment, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
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Perez-Matas E, Hanano A, Moyano E, Bonfill M, Cusido RM, Palazon J. Insights into the control of taxane metabolism: Molecular, cellular, and metabolic changes induced by elicitation in Taxus baccata cell suspensions. FRONTIERS IN PLANT SCIENCE 2022; 13:942433. [PMID: 35968149 PMCID: PMC9372332 DOI: 10.3389/fpls.2022.942433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
More knowledge is needed about the molecular/cellular control of paclitaxel (PTX) production in Taxus spp. cell cultures. In this study, the yield of this anticancer agent in Taxus baccata cell suspensions was improved 11-fold after elicitation with coronatine (COR) compared to the untreated cells, and 18-fold when co-supplemented with methyl-β-cyclodextrins (β-CDs). In the dual treatment, the release of taxanes from the producer cells was greatly enhanced, with 81.6% of the total taxane content being found in the medium at the end of the experiment. The experimental conditions that caused the highest PTX production also induced its maximum excretion, and increased the expression of taxane biosynthetic genes, especially the flux-limiting BAPT and DBTNBT. The application of COR, which activates PTX biosynthesis, together with β - CDs, which form inclusion complexes with PTX and related taxanes, is evidently an efficient strategy for enhancing PTX production and release to the culture medium. Due to the recently described role of lipid droplets (LDs) in the trafficking and accumulation of hydrophobic taxanes in Taxus spp. cell cultures, the structure, number and taxane storage capacity of these organelles was also studied. In elicited cultures, the number of LDs increased and they mainly accumulated taxanes with a side chain, especially PTX. Thus, PTX constituted up to 50-70% of the total taxanes found in LDs throughout the experiment in the COR + β - CD-treated cultures. These results confirm that LDs can store taxanes and distribute them inside and outside cells.
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Affiliation(s)
- Edgar Perez-Matas
- Secció de Fisiologia Vegetal, Facultat de Farmacia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
| | - Abdulsamie Hanano
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria
| | - Elisabeth Moyano
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Mercedes Bonfill
- Secció de Fisiologia Vegetal, Facultat de Farmacia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
| | - Rosa M. Cusido
- Secció de Fisiologia Vegetal, Facultat de Farmacia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
| | - Javier Palazon
- Secció de Fisiologia Vegetal, Facultat de Farmacia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
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Chen X, Wang P, Wei M, Lin X, Gu M, Fang W, Zheng Y, Zhao F, Jin S, Ye N. Lipidomics analysis unravels changes from flavor precursors in different processing treatments of purple-leaf tea. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:3730-3741. [PMID: 34919290 DOI: 10.1002/jsfa.11721] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/17/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Lipids are one of the most important bioactive compounds, affecting the character and quality of tea. However, the contribution of lipids to tea productions is still elusive. Here, we systematically identified the lipid profiles of green, oolong, and black teas in purple-leaf tea (Jinmingzao, JMZ) and green-leaf tea (Huangdan, HD), respectively. RESULTS The lipids analysis showed regular accumulation in tea products with different manufacturing processes, among which the fatty acids, glycerolipids, glycerophospholipids, and sphingolipids contribute to the quality characteristics of tea products, including typical fatty acyl (FA), monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerols (DGDG), and phosphatidylcholine (PC). Compared tea materials with products, levels of fatty acids were up-regulated, while glycerolipids and glycerophospholipids were down-regulated in tea products. FA 18:3, FA 16:0, MGDG 36:6, DGDG 36:6, PC 34:3, and PC 36:6 were the negative contributors to green tea flavor formation of purple-leaf tea. The pathway analysis of significant lipids in materials and products of purple-leaf tea were enriched linolenic acid metabolism pathway and glycerolipid metabolism. CONCLUSION This study provides insights into the lipid metabolism profiles of different tea leaf colors, and found that fatty acids are essential precursors of black tea flavor formation. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Xuejin Chen
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Pengjie Wang
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
| | - Mingxiu Wei
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
| | - Xinying Lin
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
| | - Mengya Gu
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
| | - Wanping Fang
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Yucheng Zheng
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
| | - Feng Zhao
- School of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Shan Jin
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
| | - Naixing Ye
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in University of Fujian Province, Fuzhou, China
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Dynamic Variation of Amino Acid Contents and Identification of Sterols in Xinyang Mao Jian Green Tea. Molecules 2022; 27:molecules27113562. [PMID: 35684499 PMCID: PMC9182030 DOI: 10.3390/molecules27113562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/23/2022] [Accepted: 05/30/2022] [Indexed: 02/06/2023] Open
Abstract
As important biomolecules in Camellia sinensis L., amino acids (AAs) are considered to contribute to the overall green tea sensory quality and undergo dynamic changes during growth. However, limited by analytical capacity, detailed AAs composition in different growth stages remains unclear. To address this question, we analyzed the dynamic changes of 23 AAs during leaf growth in Xinyang Mao Jian (XYMJ) green tea. Using amino acid analyzer, we demonstrated that most AAs are abundant on Pure Brightness Day and Grain Rain Day. After Grain Rain, 23 AAs decreased significantly. Further analysis shows that theanine has a high level on the day before Spring Equinox and Grain Rain, accounting for 44–61% of the total free AAs content in tea leaves. Glu, Pro, and Asp are the second most abundant AAs. Additionally, spinasterol and 22,23-dihydrospinasterol are first purified and identified in ethanol extract of XYMJ by silica gel column chromatography method. This study reveals the relationship between plucking days and the dynamic changes of AAs during the growth stage and proves the rationality of the traditional plucking days of XYMJ green tea.
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Chen M. The Tea Plant Leaf Cuticle: From Plant Protection to Tea Quality. FRONTIERS IN PLANT SCIENCE 2021; 12:751547. [PMID: 34659320 PMCID: PMC8519587 DOI: 10.3389/fpls.2021.751547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 08/30/2021] [Indexed: 05/29/2023]
Abstract
Camellia sinensis (tea tree) is a perennial evergreen woody crop that has been planted in more than 50 countries worldwide; its leaves are harvested to make tea, which is one of the most popular nonalcoholic beverages. The cuticle is the major transpiration barrier to restrict nonstomatal water loss and it affects the drought tolerance of tea plants. The cuticle may also provide molecular cues for the interaction with herbivores and pathogens. The tea-making process almost always includes a postharvest withering treatment to reduce leaf water content, and many studies have demonstrated that withering treatment-induced metabolite transformation is essential to shape the quality of the tea made. Tea leaf cuticle is expected to affect its withering properties and the dynamics of postharvest metabolome remodeling. In addition, it has long been speculated that the cuticle may contribute to the aroma quality of tea. However, concrete experimental evidence is lacking to prove or refute this hypothesis. Even though its relevance to the abiotic and biotic stress tolerance and postharvest processing properties of tea tree, tea cuticle has long been neglected. Recently, there are several studies on the tea cuticle regarding its structure, wax composition, transpiration barrier organization, environmental stresses-induced wax modification, and structure-function relations. This review is devoted to tea cuticle, the recent research progresses were summarized and unresolved questions and future research directions were also discussed.
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Affiliation(s)
- Mingjie Chen
- College of Life Sciences, Henan Provincial Key Laboratory of Tea Plant Biology, Xinyang Normal University, Xinyang, China
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Abstract
Cytosolic lipid droplets (LDs) are organelles which emulsify a variety of hydrophobic molecules in the aqueous cytoplasm of essentially all plant cells. Most familiar are the LDs from oilseeds or oleaginous fruits that primarily store triacylglycerols and serve a storage function. However, similar hydrophobic particles are found in cells of plant tissues that package terpenoids, sterol esters, wax esters, or other types of nonpolar lipids. The various hydrophobic lipids inside LDs are coated with a phospholipid monolayer, mostly derived from membrane phospholipids during their ontogeny. Various proteins have been identified to be associated with LDs, and these may be cell-type, tissue-type, or even species specific. While major LD proteins like oleosins have been known for decades, more recently a growing list of LD proteins has been identified, primarily by proteomics analyses of isolated LDs and confirmation of their localization by confocal microscopy. LDs, unlike other organelles, have a density less than that of water, and consequently can be isolated and enriched in cellular fractions by flotation centrifugation for composition studies. However, due to its deep coverage, modern proteomics approaches are also prone to identify contaminants, making control experiments necessary. Here, procedures for the isolation of LDs, and analysis of LD components are provided as well as methods to validate the LD localization of proteins.
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