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Tunstad SA, Bull ID, Rands SA, Whitney HM. The cuticular wax composition and crystal coverage of leaves and petals differ in a consistent manner between plant species. Open Biol 2024; 14:230430. [PMID: 38806146 DOI: 10.1098/rsob.230430] [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: 11/22/2023] [Accepted: 03/26/2024] [Indexed: 05/30/2024] Open
Abstract
Both leaves and petals are covered in a cuticle, which itself contains and is covered by cuticular waxes. The waxes perform various roles in plants' lives, and the cuticular composition of leaves has received much attention. To date, the cuticular composition of petals has been largely ignored. Being the outermost boundary between the plant and the environment, the cuticle is the first point of contact between a flower and a pollinator, yet we know little about how plant-pollinator interactions shape its chemical composition. Here, we investigate the general structure and composition of floral cuticular waxes by analysing the cuticular composition of leaves and petals of 49 plant species, representing 19 orders and 27 families. We show that the flowers of plants from across the phylogenetic range are nearly devoid of wax crystals and that the total wax load of leaves in 90% of the species is higher than that of petals. The proportion of alkanes is higher, and the chain lengths of the aliphatic compounds are shorter in petals than in leaves. We argue these differences are a result of adaptation to the different roles leaves and petals play in plant biology.
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Affiliation(s)
| | - Ian D Bull
- Organic Geochemistry Unit, School of Chemistry, University of Bristol , Bristol, UK
| | - Sean A Rands
- School of Biological Sciences, University of Bristol , Bristol, UK
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2
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Gozdzik J, Busta L, Jetter R. Leaf cuticular waxes of wild-type Welsh onion (Allium fistulosum L.) and a wax-deficient mutant: Compounds with terminal and mid-chain functionalities. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 198:107679. [PMID: 37121165 DOI: 10.1016/j.plaphy.2023.107679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/21/2023] [Accepted: 04/02/2023] [Indexed: 05/02/2023]
Abstract
Plant cuticles cover aerial organs to limit non-stomatal water loss and protect against insects and pathogens. Cuticles contain complex mixtures of fatty acid-derived waxes, with various chain lengths and diverse functional groups. To further our understanding of the chemical diversity and biosynthesis of these compounds, this study investigated leaf cuticular waxes of Welsh onion (Allium fistulosum L.) wild type and a wax-deficient mutant. Leaf waxes were extracted with chloroform, separated using thin layer chromatography (TLC), and analyzed using gas chromatography-mass spectrometry (GC-MS). The extracts contained typical wax compound classes found in nearly all plant lineages but also two uncommon compound classes. Analyses of characteristic MS fragmentation patterns followed by comparisons with synthetic standards identified the latter as very-long-chain ketones and primary ketols. The ketols were minor compounds, with chain lengths ranging from C28 to C32 and carbonyls mainly on C-18 and C-20 in wild type wax, and a C28 chain with C-16 carbonyl in the mutant. The ketones made up 70% of total wax in the wild type, consisting mainly of C31 isomers with carbonyl group on C-14 or C-16. In contrast, the mutant wax comprised only 4% ketones, with chain lengths C27 and C29 and carbonyls predominantly on C-12 and C-14, respectively. A two-carbon homolog shift between wild type and mutant was also observed in the primary alcohols (a major wax compound class), whilst alkanes exhibited a four-carbon shift. Overall, the compositional data shed light on possible biosynthetic pathways to wax ketones that can be tested in future studies.
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Affiliation(s)
- Jedrzej Gozdzik
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Lucas Busta
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, MN, 55812, USA
| | - Reinhard Jetter
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada; Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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3
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Jaroensuk J, Intasian P, Wattanasuepsin W, Akeratchatapan N, Kesornpun C, Kittipanukul N, Chaiyen P. Enzymatic reactions and pathway engineering for the production of renewable hydrocarbons. J Biotechnol 2020; 309:1-19. [DOI: 10.1016/j.jbiotec.2019.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/14/2019] [Accepted: 12/15/2019] [Indexed: 01/23/2023]
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4
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Guo Y, Li JJ, Busta L, Jetter R. Coverage and composition of cuticular waxes on the fronds of the temperate ferns Pteridium aquilinum, Cryptogramma crispa, Polypodium glycyrrhiza, Polystichum munitum and Gymnocarpium dryopteris. ANNALS OF BOTANY 2018; 122:555-568. [PMID: 30252045 PMCID: PMC6153475 DOI: 10.1093/aob/mcy078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 04/23/2018] [Indexed: 05/16/2023]
Abstract
BACKGROUND AND AIMS The cuticular waxes sealing plant surfaces against excessive water loss are complex mixtures of very-long-chain aliphatics, with compositions that vary widely between plant species. To help fill the gap in our knowledge about waxes of non-flowering plant taxa, and thus about the cuticle of ancestral land plants, this study provides comprehensive analyses of waxes on temperate fern species from five different families. METHODS The wax mixtures on fronds of Pteridium aquilinum, Cryptogramma crispa, Polypodium glycyrrhiza, Polystichum munitum and Gymnocarpium dryopteris were analysed using gas chromatography-mass spectrometry for identification, and gas chromatography-flame ionization detection for quantification. KEY RESULTS The wax mixtures from all five fern species contained large amounts of C36-C54 alkyl esters, with species-specific homologue distributions. They were accompanied by minor amounts of fatty acids, primary alcohols, aldehydes and/or alkanes, whose chain length profiles also varied widely between species. In the frond wax of G. dryopteris, C27-C33 secondary alcohols and C27-C35 ketones with functional groups exclusively on even-numbered carbons (C-10 to C-16) were identified; these are characteristic structures similar to secondary alcohols and ketones in moss, gymnosperm and basal angiosperm waxes. The ferns had total wax amounts varying from 3.9 μg cm-2 on P. glycyrrhiza to 16.9 μg cm-2 on G. dryopteris, thus spanning a range comparable with that on leaves of flowering plants. CONCLUSIONS The characteristic compound class compositions indicate that all five fern species contain the full complement of wax biosynthesis enzymes previously described for the angiosperm arabidopsis. Based on the isomer profiles, we predict that each fern species, in contrast to arabidopsis, has multiple ester synthase enzymes, each with unique substrate specificities.
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Affiliation(s)
- Yanjun Guo
- College of Agronomy and Biotechnology, Southwest University, Chongqing, China
- Department of Botany, University of British Columbia, University Boulevard, Vancouver, BC, Canada
| | - Jia Jun Li
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Lucas Busta
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
- Present address: Center for Plant Science Innovation, 1901 Vine Street, Lincoln, NE 68588, USA
| | - Reinhard Jetter
- Department of Botany, University of British Columbia, University Boulevard, Vancouver, BC, Canada
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
- For correspondence. E-mail
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Hegebarth D, Jetter R. Cuticular Waxes of Arabidopsis thaliana Shoots: Cell-Type-Specific Composition and Biosynthesis. PLANTS (BASEL, SWITZERLAND) 2017; 6:E27. [PMID: 28686187 PMCID: PMC5620583 DOI: 10.3390/plants6030027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/02/2017] [Accepted: 07/02/2017] [Indexed: 02/03/2023]
Abstract
It is generally assumed that all plant epidermis cells are covered with cuticles, and the distinct surface geometries of pavement cells, guard cells, and trichomes imply functional differences and possibly different wax compositions. However, experiments probing cell-type-specific wax compositions and biosynthesis have been lacking until recently. This review summarizes new evidence showing that Arabidopsis trichomes have fewer wax compound classes than pavement cells, and higher amounts of especially long-chain hydrocarbons. The biosynthesis machinery generating this characteristic surface coating is discussed. Interestingly, wax compounds with similar, long hydrocarbon chains had been identified previously in some unrelated species, not all of them bearing trichomes.
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Affiliation(s)
- Daniela Hegebarth
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada.
| | - Reinhard Jetter
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada.
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
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Guo Y, Busta L, Jetter R. Cuticular wax coverage and composition differ among organs of Taraxacum officinale. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 115:372-379. [PMID: 28432976 DOI: 10.1016/j.plaphy.2017.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/05/2017] [Accepted: 04/05/2017] [Indexed: 05/25/2023]
Abstract
Primary plant surfaces are coated with hydrophobic cuticular waxes to minimize non-stomatal water loss. Wax compositions differ greatly between plant species and, in the few species studied systematically so far, also between organs, tissues, and developmental stages. However, the wax mixtures of more species in diverse plant families must be investigated to assess overall wax variability, and ultimately to correlate organ-specific composition with local water barrier properties. Here, we present comprehensive analyses of the waxes covering five organs of Taraxacum officinale (dandelion), to help close a gap in our understanding of wax chemistry in the Asteraceae family. First, novel wax constituents of the petal wax were identified as C25 6,8- and 8,10-ketols as well as C27 6,8- and 8,10-ketols. Nine other component classes (fatty acids, primary alcohols, esters, aldehydes, alkanes, triterpenols, triterpene acetates, sterols, and tocopherols) were detected in the wax mixtures covering leaves, peduncles, and petals, as well as fruit beaks and pappi. Wax coverages varied from 5 μg/cm2 on peduncles to 37 μg/cm2 on petals. Alcohols predominated in leaf wax, while both alcohols and alkanes were found in similar amounts on peduncles and petals, and mainly alkanes on the fruit beaks and pappi. Chain length distributions within the wax compound classes were similar between organs, centered around C26 for fatty acids, alcohols, and aldehydes, and C29 for alkanes. However, the quantities of homologs with longer chain lengths varied substantially between organs, reaching well beyond C30 on all surfaces except leaves, suggesting differences in elongation enzymes determining the alkyl chain structures. The detailed wax profiles presented here will serve as basis for future investigations into wax biosynthesis in the Asteraceae and into wax functions on different dandelion organs.
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Affiliation(s)
- Yanjun Guo
- College of Agronomy and Biotechnology, Southwest University, Chongqing, 400716, China
| | - Lucas Busta
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Reinhard Jetter
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada; Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada.
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Racovita RC, Jetter R. Identification of In-Chain-Functionalized Compounds and Methyl-Branched Alkanes in Cuticular Waxes of Triticum aestivum cv. Bethlehem. PLoS One 2016; 11:e0165827. [PMID: 27820857 PMCID: PMC5098774 DOI: 10.1371/journal.pone.0165827] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 10/07/2016] [Indexed: 12/02/2022] Open
Abstract
In this work, cuticular waxes from flag leaf blades and peduncles of Triticum aestivum cv. Bethlehem were investigated in search for novel wax compounds. Seven wax compound classes were detected that had previously not been reported, and their structures were elucidated using gas chromatography-mass spectrometry of various derivatives. Six of the classes were identified as series of homologs differing by two methylene units, while the seventh was a homologous series with homologs with single methylene unit differences. In the waxes of flag leaf blades, secondary alcohols (predominantly C27 and C33), primary/secondary diols (predominantly C28) and esters of primary/secondary diols (predominantly C50, combining C28 diol with C22 acid) were found, all sharing similar secondary hydroxyl group positions at and around C-12 or ω-12. 7- and 8-hydroxy-2-alkanol esters (predominantly C35), 7- and 8-oxo-2-alkanol esters (predominantly C35), and 4-alkylbutan-4-olides (predominantly C28) were found both in flag leaf and peduncle wax mixtures. Finally, a series of even- and odd-numbered alkane homologs was identified in both leaf and peduncle waxes, with an internal methyl branch preferentially on C-11 and C-13 of homologs with even total carbon number and on C-12 of odd-numbered homologs. Biosynthetic pathways are suggested for all compounds, based on common structural features and matching chain length profiles with other wheat wax compound classes.
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Affiliation(s)
- Radu C. Racovita
- Department of Chemistry, The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Reinhard Jetter
- Department of Chemistry, The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
- Department of Botany, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- * E-mail:
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Identification of Polyketides in the Cuticular Waxes of Triticum aestivum cv. Bethlehem. Lipids 2016; 51:1407-1420. [PMID: 27796867 DOI: 10.1007/s11745-016-4208-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022]
Abstract
Cuticular waxes are complex mixtures consisting mostly of very-long-chain aliphatics with single, primary functional groups. However, the waxes of many plant species also include aliphatics with one or more functional groups residing on subterminal or mid-chain carbons. In the present work, the cuticular wax mixtures from flag leaf blades and peduncles of Triticum aestivum cv. Bethlehem were analyzed in a search for novel wax constituents with in-chain functionalities, potentially of polyketide origin. The structures of compounds belonging to six different compound classes were elucidated using gas chromatography-mass spectrometry of various derivatives. Among them, a series of 2,4-ketols was identified, with odd carbon numbers ranging from C25 to C37 and peaking at C33. The analogous C33 2,4-diketone was identified as well, together with a pair of co-eluting C31 mid-chain β-ketol isomers (16-hydroxyhentriacontan-14-one and 14-hydroxyhentriacontan-16-one), a pair of co-eluting C30 mid-chain α-ketol isomers (15-hydroxytriacontan-14-one and 14-hydroxytriacontan-15-one), the corresponding C30 14,15-diketone, and a pair of co-eluting C31 ketones (hentriacontan-14-one and hentriacontan-16-one). All newly discovered structures contain ketone functional groups, with similar C13H27 and C15H31 alkyl chains on either side of the functionalities, thus resembling the previously reported very-long-chain β-diketones dominating the wheat wax mixtures. Based on these structural characteristics, possible biosynthetic pathways leading to the newly identified polyketide-like compounds are proposed.
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Racovita RC, Jetter R. Composition of the epicuticular waxes coating the adaxial side of Phyllostachys aurea leaves: Identification of very-long-chain primary amides. PHYTOCHEMISTRY 2016; 130:252-261. [PMID: 27402630 DOI: 10.1016/j.phytochem.2016.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 06/05/2016] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
The present study presents comprehensive chemical analyses of cuticular wax mixtures of the bamboo Phyllostachys aurea. The epicuticular and intracuticular waxes were sampled selectively from the adaxial side of leaves on young and old plants and investigated by gas chromatography-mass spectrometry and flame ionization detection. The epi- and intracuticular layers on young and old leaves had wax loads ranging from 1.7 μg/cm(2) to 1.9 μg/cm(2). Typical very-long-chain aliphatic wax constituents were found with characteristic chain length patterns, including alkyl esters (primarily C48), alkanes (primarily C29), fatty acids (primarily C28 and C16), primary alcohols (primarily C28) and aldehydes (primarily C30). Alicyclic wax components were identified as tocopherols and triterpenoids, including substantial amounts of triterpenoid esters. Alkyl esters, alkanes, fatty acids and aldehydes were found in greater amounts in the epicuticular layer, while primary alcohols and most terpenoids accumulated more in the intracuticular wax. Alkyl esters occurred as mixtures of metamers, combining C20 alcohol with various acids into shorter ester homologs (C36C40), and a wide range of alcohols with C22 and C24 acids into longer esters (C42C52). Primary amides were identified, with a characteristic chain length profile peaking at C30. The amides were present exclusively in the epicuticular layer and thus at or near the surface, where they may affect plant-herbivore or plant-pathogen interactions.
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Affiliation(s)
- Radu C Racovita
- Department of Chemistry, The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Reinhard Jetter
- Department of Chemistry, The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada; Department of Botany, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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10
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Racovita RC, Hen-Avivi S, Fernandez-Moreno JP, Granell A, Aharoni A, Jetter R. Composition of cuticular waxes coating flag leaf blades and peduncles of Triticum aestivum cv. Bethlehem. PHYTOCHEMISTRY 2016; 130:182-92. [PMID: 27264640 DOI: 10.1016/j.phytochem.2016.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/05/2016] [Accepted: 05/11/2016] [Indexed: 05/10/2023]
Abstract
The work herein presents comprehensive analyses of the cuticular wax mixtures covering the flag leaf blade and peduncle of bread wheat (Triticum aestivum) cv. Bethlehem. Overall, Gas Chromatography-Mass Spectrometry and Flame Ionization Detection revealed a wax coverage of flag leaf blades (16 μg/cm(2)) a third that of peduncles (49 μg/cm(2)). Flag leaf blade wax was dominated by 1-alkanols, while peduncle wax contained primarily β-diketone and hydroxy-β-diketones, thus suggesting differential regulation of the acyl reduction and β-diketone biosynthetic pathways in the two analyzed organs. The characteristic chain length distributions of the various wax compound classes are discussed in light of their individual biosynthetic pathways and biosynthetic relationships between classes. Along with previously reported wheat wax compound classes (fatty acids, 1-alkanols, 1-alkanol esters, aldehydes, alkanes, β-diketone, hydroxy-β-diketones, alkylresorcinols and methyl alkylresorcinols), esters of 2-alkanols and three types of aromatic esters (benzyl, phenethyl and p-hydroxyphenethyl) are also reported. In particular, 2-heptanol esters were identified. Detailed analyses of the isomer distributions within 1-alkanol and 2-alkanol ester homologs revealed distinct patterns of esterified acids and alcohols, suggesting several wax ester synthases with very different substrate preferences in both wheat organs. Terpenoids, including two terpenoid esters, were present only in peduncle wax.
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Affiliation(s)
- Radu C Racovita
- Department of Chemistry, The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Shelly Hen-Avivi
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | | | - Antonio Granell
- Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV), Universidad Politécnica de Valencia, Valencia, 46022, Spain
| | - Asaph Aharoni
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Reinhard Jetter
- Department of Chemistry, The University of British Columbia, Vancouver, BC, V6T 1Z1, Canada; Department of Botany, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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11
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Schneider LM, Adamski NM, Christensen CE, Stuart DB, Vautrin S, Hansson M, Uauy C, von Wettstein-Knowles P. The Cer-cqu gene cluster determines three key players in a β-diketone synthase polyketide pathway synthesizing aliphatics in epicuticular waxes. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2715-2730. [PMID: 26962211 PMCID: PMC4861019 DOI: 10.1093/jxb/erw105] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Aliphatic compounds on plant surfaces, called epicuticular waxes, are the first line of defense against pathogens and pests, contribute to reducing water loss and determine other important phenotypes. Aliphatics can form crystals affecting light refraction, resulting in a color change and allowing identification of mutants in their synthesis or transport. The present study discloses three such Eceriferum (cer) genes in barley - Cer-c, Cer-q and Cer-u - known to be tightly linked and functioning in a biochemical pathway forming dominating amounts of β-diketone and hydroxy-β-diketones plus some esterified alkan-2-ols. These aliphatics are present in many Triticeae as well as dicotyledons such as Eucalyptus and Dianthus. Recently developed genomic resources and mapping populations in barley defined these genes to a small region on chromosome arm 2HS. Exploiting Cer-c and -u potential functions pinpointed five candidates, of which three were missing in apparent cer-cqu triple mutants. Sequencing more than 50 independent mutants for each gene confirmed their identification. Cer-c is a chalcone synthase-like polyketide synthase, designated diketone synthase (DKS), Cer-q is a lipase/carboxyl transferase and Cer-u is a P450 enzyme. All were highly expressed in pertinent leaf sheath tissue of wild type. A physical map revealed the order Cer-c, Cer-u, Cer-q with the flanking genes 101kb apart, confirming they are a gene cluster, Cer-cqu. Homology-based modeling suggests that many of the mutant alleles affect overall protein structure or specific active site residues. The rich diversity of identified mutations will facilitate future studies of three key enzymes involved in synthesis of plant apoplast waxes.
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Affiliation(s)
- Lizette M Schneider
- Biology Department, Copenhagen University, Copenhagen DK-2200, Denmark Biology Department, Lund University, SW-22362 Lund, Sweden
| | | | | | - David B Stuart
- Biology Department, Lund University, SW-22362 Lund, Sweden
| | - Sonia Vautrin
- INRA-Centre National de Ressources Génomiques Végétales, F-31326 Castanet Tolosan, France
| | - Mats Hansson
- Biology Department, Lund University, SW-22362 Lund, Sweden
| | - Cristobal Uauy
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
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12
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Busta L, Budke JM, Jetter R. Identification of β-hydroxy fatty acid esters and primary, secondary-alkanediol esters in cuticular waxes of the moss Funaria hygrometrica. PHYTOCHEMISTRY 2016; 121:38-49. [PMID: 26553812 DOI: 10.1016/j.phytochem.2015.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 10/08/2015] [Accepted: 10/27/2015] [Indexed: 05/29/2023]
Abstract
The plant cuticle, a multi-layered membrane that covers plant aerial surfaces to prevent desiccation, consists of the structural polymer cutin and surface-sealing waxes. Cuticular waxes are complex mixtures of ubiquitous, typically monofunctional fatty acid derivatives and taxon-specific, frequently bifunctional specialty compounds. To further our understanding of the chemical diversity of specialty compounds, the waxes on the aerial structures of the leafy gametophyte, sporophyte capsule, and calyptra of the moss Funaria hygrometrica were surveyed. Respective moss surfaces were extracted, and resulting lipid mixtures were analyzed by gas chromatography-mass spectrometry (GC-MS). The extracts contained ubiquitous wax compound classes along with two prominent, unidentified classes of compounds that exhibited some characteristics of bifunctional structures. Microscale transformations led to derivatives with characteristic MS fragmentation patterns suggesting possible structures for these compounds. To confirm the tentative structure assignments, one compound in each of the suspected homologous series was synthesized. Based on GC-MS comparison with the authentic standards, the first series of compounds was identified as containing esters formed by β-hydroxy fatty acids and wax alcohols, with ester chain lengths varying from C42 to C50 and the most prominent homolog being C46. The second series consisted of fatty acid esters of 1,7-alkanediols, linked via the primary hydroxyl group, with ester chain lengths C40-C52 also dominated by the C46 homolog. The β-hydroxy acid esters were restricted to the sporophyte capsule, and the diol esters to the leafy gametophyte and calyptra. Based on their homolog and isomer distributions, and the presence of free 1,7-triacontanediol, possible biosynthetic reactions leading to these compounds are discussed.
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Affiliation(s)
- Lucas Busta
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Jessica M Budke
- Department of Plant Biology, University of California - Davis, One Shields Ave., Davis, CA 95616, USA
| | - Reinhard Jetter
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada; Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada.
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13
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Racovita RC, Peng C, Awakawa T, Abe I, Jetter R. Very-long-chain 3-hydroxy fatty acids, 3-hydroxy fatty acid methyl esters and 2-alkanols from cuticular waxes of Aloe arborescens leaves. PHYTOCHEMISTRY 2015; 113:183-94. [PMID: 25200334 DOI: 10.1016/j.phytochem.2014.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/08/2014] [Accepted: 07/11/2014] [Indexed: 05/18/2023]
Abstract
The present work aimed at a comprehensive chemical characterization of the cuticular wax mixtures covering leaves of the monocot species Aloe arborescens. The wax mixtures were found to contain typical aliphatic compound classes in characteristic chain length distributions, including alkanes (predominantly C31), primary alcohols (predominantly C28), aldehydes (predominantly C32), fatty acid methyl esters (predominantly C28) and fatty acids (bimodal distribution around C32 and C28). Alkyl esters ranging from C42 to C52 were identified, and found to mainly contain C28 alcohol linked to C16-C20 acids. Three other homologous series were identified as 3-hydroxy fatty acids (predominantly C28), their methyl esters (predominantly C28), and 2-alkanols (predominantly C31). Based on structural similarities and homolog distributions, the biosynthetic pathways leading to these novel wax constituents can be hypothesized. Further detailed analyses showed that the A. arborescens leaf was covered with 15 μg/cm(2) wax on its adaxial side and 36 μg/cm(2) on the abaxial side, with 3:2 and 1:1 ratios between epicuticular and intracuticular wax layers on each side, respectively. Terpenoids were found mainly in the intracuticular waxes, whereas very-long-chain alkanes and fatty acids accumulated to relatively high concentrations in the epicuticular wax, hence near the true surface of the leaf.
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Affiliation(s)
- Radu C Racovita
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Chen Peng
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Takayoshi Awakawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Reinhard Jetter
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada; Department of Botany, The University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada.
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14
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Ganapaty S, Rao DV, Pannakal ST. A Phenethyl bromo ester from Citharexylum fruticosum. Nat Prod Commun 2010. [DOI: 10.1177/1934578x1000500312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A new compound, (2 S)- p-hydroxyphenethyl 2-bromo-2-methyldodeconate (1) and 7,3′-dimethoxy-5,4′-dihydroxy flavone, together with lupeol and stigmasterol were isolated from the stem bark of Citharexylum fruticosum (Verbenaceae). The structures of the compounds were established on the basis of the interpretation of NMR (1H, 13C, COSY and HMBC) spectra, as well as low and high-resolution mass spectrometric data. In this paper, we report on the structure elucidation of 1.
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Affiliation(s)
- Seru Ganapaty
- Pharmacognosy and Phytochemistry Division, University College of Pharmaceutical Sciences, Andhra University, Visakhapatnam-530 003, Andhra Pradesh, India
| | - Desaraju Venkata Rao
- Pharmacognosy and Phytochemistry Division, University College of Pharmaceutical Sciences, Andhra University, Visakhapatnam-530 003, Andhra Pradesh, India
| | - Steve Thomas Pannakal
- Department of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, Madhav nagar, Manipal University, Manipal, Karnataka-576 104, India
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15
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Lai C, Kunst L, Jetter R. Composition of alkyl esters in the cuticular wax on inflorescence stems of Arabidopsis thaliana cer mutants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 50:189-96. [PMID: 17376164 DOI: 10.1111/j.1365-313x.2007.03054.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Wax biosynthetic pathways proceed via the elongation of 16:0 acyl-CoA to very long-chain fatty acids (VLCFA), and by further modifications that include reduction to primary alcohols and formation of alkyl esters. We have analyzed the alkyl esters in the stem wax of ten cer mutants of Arabidopsis thaliana together with the corresponding wild types. Alkyl esters with chain lengths between C(38) and C(52) were identified, and the levels of esters ranged from 0.15 microg cm(-2) in Wassilewskija (WS) to 1.20 microg cm(-2) in cer2. Esters with even numbers of carbons prevailed, with C(42), C(44) and C(46) favoured in the wild types, a predominance of C(42) in cer2 and cer6 mutants, and a relative shift towards C(46) in cer3 and cer23 mutants. The esters of all mutants and wild types were dominated by 16:0 acyl moieties, whereas the chain lengths of esterified alcohols were between C(20) and C(32). The alkyl chain-length distributions of the wild-type esters had a maximum for C(28) alcohol, similar to the free alcohols accompanying them in the wax mixtures. The esterified alcohols of cer2, cer6 and cer9 had largely increased levels of C(26) alcohol, closely matching the patterns of the corresponding free alcohols and, therefore, differing drastically from the corresponding wild type. In contrast, cer1, cer3, cer10, cer13 and cer22 showed ester alcohol patterns with increased levels of C(30), only partially following the shift in chain lengths of the free alcohols in stem wax. These results provide information on the composition of substrate pools and/or the specificity of the ester synthase involved in wax ester formation. We conclude that alcohol levels at the site of biosynthesis are mainly limiting the ester formation in the Arabidopsis wild-type epidermis.
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Affiliation(s)
- Christine Lai
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada
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16
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Wen M, Au J, Gniwotta F, Jetter R. Very-long-chain secondary alcohols and alkanediols in cuticular waxes of Pisum sativum leaves. PHYTOCHEMISTRY 2006; 67:2494-502. [PMID: 16997335 DOI: 10.1016/j.phytochem.2006.08.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 07/14/2006] [Accepted: 08/11/2006] [Indexed: 05/11/2023]
Abstract
In cuticular waxes from leaves of Pisum sativum, 19 secondary alcohols, 10 primary/secondary alkanediols and three secondary/secondary alkanediols were identified by various chemical transformations with product assignment employing GC-MS. The homologous series of C29-C33 secondary alcohols (1.1 microg/cm2) was dominated by hentriacontanol isomers (94%). Only octacosanediols and trace amounts of hexacosanediols (< 1%) were detected in the primary/secondary alkanediol faction (0.7 microg/cm2). The secondary/secondary alkanediols (0.12 microg/cm2) contained a single homologue with chain length C31. All three compound classes showed characteristic isomer distributions with secondary functional groups predominantly located between C-14 and C-16. Based on the isomer compositions, the sequence of biosynthetic steps introducing the hydroxyl functions is discussed.
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Affiliation(s)
- Miao Wen
- Department of Botany, University of British Columbia, Vancouver, Canada V6T 1Z4
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17
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da Luz BR. Attenuated total reflectance spectroscopy of plant leaves: a tool for ecological and botanical studies. THE NEW PHYTOLOGIST 2006; 172:305-18. [PMID: 16995918 DOI: 10.1111/j.1469-8137.2006.01823.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Attenuated total reflectance (ATR) spectra of plant leaves display complex absorption features related to organic constituents of leaf surfaces. The spectra can be recorded rapidly, both in the field and in the laboratory, without special sample preparation. This paper explores sources of ATR spectral variation in leaves, including compositional, positional and temporal variations. Interspecific variations are also examined, including the use of ATR spectra as a tool for species identification. Positional spectral variations generally reflected the abundance of cutin and the epicuticular wax thickness and composition. For example, leaves exposed to full sunlight commonly showed more prominent cutin- and wax-related absorption features compared with shaded leaves. Adaxial vs. abaxial leaf surfaces displayed spectral variations reflecting differences in trichome abundance and wax composition. Mature vs. young leaves showed changes in absorption band position and intensity related to cutin, polysaccharide, and possibly amorphous silica development on and near the leaf surfaces. Provided that similar samples are compared (e.g. adaxial surfaces of mature, sun-exposed leaves) same-species individuals display practically identical ATR spectra. Using spectral matching procedures to analyze an ATR database containing 117 individuals, including 32 different tree species, 83% of the individuals were correctly identified.
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Affiliation(s)
- Beatriz Ribeiro da Luz
- Department of Ecology, Institute of Biosciences, University of São Paulo. R. do Matão, Travessa 14, 321, 05508-900, São Paulo, SP, Brazil.
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18
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Szafranek BM, Synak EE. Cuticular waxes from potato (Solanum tuberosum) leaves. PHYTOCHEMISTRY 2006; 67:80-90. [PMID: 16310230 DOI: 10.1016/j.phytochem.2005.10.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 10/06/2005] [Accepted: 10/10/2005] [Indexed: 05/05/2023]
Abstract
The qualitative and quantitative compositions of leaf cuticular waxes from potato (Solanum tuberosum) varieties were studied. The principal components of the waxes were very long chain n-alkanes, 2-methylalkanes and 3-methylalkanes (3.1-4.6 microg cm(-2)), primary alcohols (0.3-0.7 microg cm(-2)), fatty acids (0.3-0.6 microg cm(-2)), and wax esters (0.1-0.4 microg cm(-2)). Methyl ketones, sterols, beta-amyrin, benzoic acid esters and fatty acid methyl, ethyl, isopropyl and phenylethyl esters were found for the first time in potato waxes. The qualitative composition of the waxes was quite similar but there were quantitative differences between the varieties studied. A new group of cuticular wax constituents consisting of free 2-alkanols with odd and even numbers of carbon atoms ranging from C25 to C30 was identified.
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Affiliation(s)
- Beata M Szafranek
- Department of Chemistry, University of Gdańsk, Sobieskiego 18, 80-952 Gdańsk, Poland.
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19
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Abstract
In the leaf cuticular waxes of Myricaria germanica L. four different series of alkanediols were identified: (1) hentriacontanediol isomers with one functional group in the 12-position and a second group in positions ranging from 2 to 18, (2) C30-C34 alkanediols carrying one hydroxyl function on a primary and one on a secondary carbon atom. (3) homologous series of C25-C43 beta-diols predominantly with 8,10- and 10,12-functionalities, and (4) homologous series of C39-C43 gamma-diols with a predominance of 8,11- and 10,13-isomers. Primary/secondary diols and gamma-diols constituted only trace portions of the total wax mixture. The hentriacontanediols and the beta-diols amounted to 3.5 and 0.6 microg per cm2 of leaf surface area, corresponding to 9 and 2% of the wax mixture, respectively. Based on the different homolog and isomer patterns of respective diol fractions, two independent biosynthetic routes leading to the hentriacontanediols and the beta-diols are proposed.
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Affiliation(s)
- R Jetter
- Julius-von-Sachs-Institut für Biowissenschaften, Universität Würzburg, Germany.
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