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Hansson M, Youssef HM, Zakhrabekova S, Stuart D, Svensson JT, Dockter C, Stein N, Waugh R, Lundqvist U, Franckowiak J. A guide to barley mutants. Hereditas 2024; 161:11. [PMID: 38454479 PMCID: PMC10921644 DOI: 10.1186/s41065-023-00304-w] [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: 11/06/2023] [Accepted: 11/24/2023] [Indexed: 03/09/2024] Open
Abstract
BACKGROUND Mutants have had a fundamental impact upon scientific and applied genetics. They have paved the way for the molecular and genomic era, and most of today's crop plants are derived from breeding programs involving mutagenic treatments. RESULTS Barley (Hordeum vulgare L.) is one of the most widely grown cereals in the world and has a long history as a crop plant. Barley breeding started more than 100 years ago and large breeding programs have collected and generated a wide range of natural and induced mutants, which often were deposited in genebanks around the world. In recent years, an increased interest in genetic diversity has brought many historic mutants into focus because the collections are regarded as valuable resources for understanding the genetic control of barley biology and barley breeding. The increased interest has been fueled also by recent advances in genomic research, which provided new tools and possibilities to analyze and reveal the genetic diversity of mutant collections. CONCLUSION Since detailed knowledge about phenotypic characters of the mutants is the key to success of genetic and genomic studies, we here provide a comprehensive description of mostly morphological barley mutants. The review is closely linked to the International Database for Barley Genes and Barley Genetic Stocks ( bgs.nordgen.org ) where further details and additional images of each mutant described in this review can be found.
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Affiliation(s)
- Mats Hansson
- Department of Biology, Lund University, Sölvegatan 35, 22362, Lund, Sweden.
| | - Helmy M Youssef
- Faculty of Agriculture, Cairo University, Giza, 12613, Egypt
- Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle, 06120, Germany
| | | | - David Stuart
- Department of Biology, Lund University, Sölvegatan 35, 22362, Lund, Sweden
| | - Jan T Svensson
- Nordic Genetic Resource Center (NordGen), Växthusvägen 12, 23456, Alnarp, Sweden
| | - Christoph Dockter
- Carlsberg Research Laboratory, J. C. Jacobsens Gade 4, 1799, Copenhagen V, Denmark
| | - Nils Stein
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Stadt Seeland, E06466, Germany
- Center for Integrated Breeding Research (CiBreed), Georg-August-University, Göttingen, Germany
| | - Robbie Waugh
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- Division of Plant Sciences, University of Dundee, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- School of Agriculture Food and Wine, Waite Campus, The University of Adelaide, Urrbrae, 5064, Australia
| | - Udda Lundqvist
- Nordic Genetic Resource Center (NordGen), Växthusvägen 12, 23456, Alnarp, Sweden
| | - Jerome Franckowiak
- Department of Agronomy and Plant Genetics, University of Minnesota Twin Cities, 411 Borlaug Hall, 1991 Upper Buford Circle, St Paul, MN, 55108, USA
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Sun Y, Ruiz Orduna A, Zhang Z, Feakins SJ, Jetter R. Biosynthesis of barley wax β-diketones: a type-III polyketide synthase condensing two fatty acyl units. Nat Commun 2023; 14:7284. [PMID: 37949901 PMCID: PMC10638390 DOI: 10.1038/s41467-023-42917-9] [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: 10/20/2022] [Accepted: 10/25/2023] [Indexed: 11/12/2023] Open
Abstract
The surface coatings of cereal plants are dominated by waxy β-diketones crucial for drought resistance and, therefore, grain yield. Here, barley (Hordeum vulgare) wax analyses reveal β-diketone and associated 2-alkanol ester profiles suggesting a common C16 3-ketoacid precursor. Isotope analysis further shows that the major (C31) diketone is synthesized from two plastidial C16 acyl units. Previous studies identified a gene cluster encoding enzymes responsible for β-diketone formation in barley, but left their biochemical functions unknown. Various assays now characterize one of these enzymes as a thioesterase producing long-chain (mainly C16) 3-ketoacids, and another one as a polyketide synthase (PKS) condensing the 3-ketoacids with long-chain (mainly C16) acyl-CoAs into β-diketones. The two enzymes are localized to the plastids and Endoplasmic Reticulum (ER), respectively, implying substrate transfer between these two sub-cellular compartments. Overall, our findings define a two-step pathway involving an unprecedented PKS reaction leading directly to the β-diketone products.
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Affiliation(s)
- Yulin Sun
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Alberto Ruiz Orduna
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Zhonghang Zhang
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Sarah J Feakins
- Department of Earth Sciences, University of Southern California, 3651 Trousdale Pkwy, Los Angeles, CA, 90089, USA
| | - Reinhard Jetter
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
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3
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Li L, Qi Z, Chai L, Chen Z, Wang T, Zhang M, You M, Peng H, Yao Y, Hu Z, Xin M, Guo W, Sun Q, Ni Z. The semidominant mutation w5 impairs epicuticular wax deposition in common wheat (Triticum aestivum L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:1213-1225. [PMID: 31965231 DOI: 10.1007/s00122-020-03543-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/10/2020] [Indexed: 05/14/2023]
Abstract
The semidominant EMS-induced mutant w5 affects epicuticular wax deposition and mapped to an approximately 194-kb region on chromosome 7DL. Epicuticular wax is responsible for the glaucous appearance of plants and protects against many biotic and abiotic stresses. In wheat (Triticum aestivum L.), β-diketone is a major component of epicuticular wax in adult plants and contributes to the glaucousness of the aerial organs. In the present study, we identified an ethyl methanesulfonate-induced epicuticular wax-deficient mutant from the elite wheat cultivar Jimai22. Compared to wild-type Jimai22, the mutant lacked β-diketone and failed to form the glaucous coating on all aerial organs. The mutant also had significantly increased in cuticle permeability, based on water loss and chlorophyll efflux. Genetic analysis indicated that the mutant phenotype is controlled by a single, semidominant gene on the long arm of chromosome 7D, which was not allelic to the known wax gene loci W1-W4, and was therefore designated W5. W5 was finely mapped to an ~ 194-kb region (flanked by the molecular markers SSR2 and STARP11) that harbored four annotated genes according to the reference genome of Chinese Spring (RefSeq v1.0). Collectively, these data will broaden the knowledge of the genetic basis underlying epicuticular wax deposition in wheat.
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Affiliation(s)
- Linghong Li
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Zhongqi Qi
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Lingling Chai
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Zhaoyan Chen
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Tianya Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Mingyi Zhang
- Dryland Agricultural Research Centre, Shanxi Academy of Agricultural Sciences, Taiyuan, 030031, China
| | - Mingshan You
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Huiru Peng
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Yingyin Yao
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Zhaorong Hu
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Mingming Xin
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Weilong Guo
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Qixin Sun
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China
- National Plant Gene Research Centre, Beijing, 100193, China
| | - Zhongfu Ni
- State Key Laboratory for Agrobiotechnology/Key Laboratory of Crop Heterosis and Utilization, The Ministry of Education/Key Laboratory of Crop Genetic Improvement, Beijing Municipality/China Agricultural University, Beijing, 100193, China.
- National Plant Gene Research Centre, Beijing, 100193, China.
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von Wettstein-Knowles P. The Polyketide Components of Waxes and the Cer-cqu Gene Cluster Encoding a Novel Polyketide Synthase, the β-Diketone Synthase, DKS. PLANTS 2017; 6:plants6030028. [PMID: 28698520 PMCID: PMC5620584 DOI: 10.3390/plants6030028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/21/2017] [Accepted: 06/30/2017] [Indexed: 01/13/2023]
Abstract
The primary function of the outermost, lipophilic layer of plant aerial surfaces, called the cuticle, is preventing non-stomatal water loss. Its exterior surface is often decorated with wax crystals, imparting a blue–grey color. Identification of the barley Cer-c, -q and -u genes forming the 101 kb Cer-cqu gene cluster encoding a novel polyketide synthase—the β-diketone synthase (DKS), a lipase/carboxyl transferase, and a P450 hydroxylase, respectively, establishes a new, major pathway for the synthesis of plant waxes. The major product is a β-diketone (14,16-hentriacontane) aliphatic that forms long, thin crystalline tubes. A pathway branch leads to the formation of esterified alkan-2-ols.
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Affiliation(s)
- Penny von Wettstein-Knowles
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Ole Maaloees Vej 5, DK-2200 Copenhagen N, Denmark.
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5
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Zhou Q, Li C, Mishina K, Zhao J, Zhang J, Duan R, Ma X, Wang A, Meng Q, Komatsuda T, Chen G. Characterization and genetic mapping of the β-diketone deficient eceriferum-b barley mutant. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2017; 130:1169-1178. [PMID: 28258370 DOI: 10.1007/s00122-017-2877-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 02/09/2017] [Indexed: 05/27/2023]
Abstract
The barley eceriferum-b.2 (cer-b.2) mutant produces glossy leaf sheaths and is deficient in the cuticular wax component 14,16-hentriacontanedione. The mutated gene maps to a 1.3-cM interval on chromosome 3HL flanked by the genes MLOC_10972 and MLOC_69561. The cuticular wax coating of leaves and stems in many grass species is responsible for the plants' glaucous appearance. A major component of the wax is a group of β-diketone compounds. The barley eceriferum-b.2 (cer-b.2) mutant produces glossy leaf sheaths and is deficient for the compound 14,16-hentriacontanedione. A linkage analysis based on 708 gametes allowed the gene responsible for the mutant phenotype to be mapped to a 1.3-cM interval on chromosome 3HL flanked by the two genes MLOC_10972 and _69561. The product of the wild type allele may represent a step in the β-diketone synthesis pathway.
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Affiliation(s)
- Qin Zhou
- Laboratory of Plant Stress Ecophysiology and Biotechnology, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chao Li
- Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Kohei Mishina
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8602, Japan
| | - Jiecai Zhao
- Laboratory of Plant Stress Ecophysiology and Biotechnology, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiwei Zhang
- Laboratory of Plant Stress Ecophysiology and Biotechnology, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruijun Duan
- College of Eco-Environmental Engineering, Qinghai University, Xining, 810016, Qinghai, China
| | - Xiaoying Ma
- Department of Biology, South University of Science and Technology of China, Shenzhen, China
| | - Aidong Wang
- Laboratory of Plant Stress Ecophysiology and Biotechnology, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qianxiang Meng
- Lanzhou Center for Oil and Gas Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Donggang west Road 382, Lanzhou, 730000, China
| | - Takao Komatsuda
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8602, Japan
| | - Guoxiong Chen
- Laboratory of Plant Stress Ecophysiology and Biotechnology, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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6
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Huang D, Feurtado JA, Smith MA, Flatman LK, Koh C, Cutler AJ. Long noncoding miRNA gene represses wheat β-diketone waxes. Proc Natl Acad Sci U S A 2017; 114:E3149-E3158. [PMID: 28351975 PMCID: PMC5393243 DOI: 10.1073/pnas.1617483114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The cuticle of terrestrial plants functions as a protective barrier against many biotic and abiotic stresses. In wheat and other Triticeae, β-diketone waxes are major components of the epicuticular layer leading to the bluish-white glaucous trait in reproductive-age plants. Glaucousness in durum wheat is controlled by a metabolic gene cluster at the WAX1 (W1) locus and a dominant suppressor INHIBITOR of WAX1 (Iw1) on chromosome 2B. The wheat D subgenome from progenitor Aegilops tauschii contains W2 and Iw2 paralogs on chromosome 2D. Here we identify the Iw1 gene from durum wheat and demonstrate the unique regulatory mechanism by which Iw1 acts to suppress a carboxylesterase-like protein gene, W1-COE, within the W1 multigene locus. Iw1 is a long noncoding RNA (lncRNA) containing an inverted repeat (IR) with >80% identity to W1-COE The Iw1 transcript forms a miRNA precursor-like long hairpin producing a 21-nt predominant miRNA, miRW1, and smaller numbers of related sRNAs associated with the nonglaucous phenotype. When Iw1 was introduced into glaucous bread wheat, miRW1 accumulated, W1-COE and its paralog W2-COE were down-regulated, and the phenotype was nonglaucous and β-diketone-depleted. The IR region of Iw1 has >94% identity to an IR region on chromosome 2 in Ae. tauschii that also produces miRW1 and lies within the marker-based location of Iw2 We propose the Iw loci arose from an inverted duplication of W1-COE and/or W2-COE in ancestral wheat to form evolutionarily young miRNA genes that act to repress the glaucous trait.
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Affiliation(s)
- Daiqing Huang
- Wheat Improvement Flagship Program, National Research Council of Canada, Saskatoon, Saskatchewan, SK S7N 0W9, Canada
| | - J Allan Feurtado
- Wheat Improvement Flagship Program, National Research Council of Canada, Saskatoon, Saskatchewan, SK S7N 0W9, Canada
| | - Mark A Smith
- Wheat Improvement Flagship Program, National Research Council of Canada, Saskatoon, Saskatchewan, SK S7N 0W9, Canada
| | - Leah K Flatman
- Wheat Improvement Flagship Program, National Research Council of Canada, Saskatoon, Saskatchewan, SK S7N 0W9, Canada
| | - Chushin Koh
- Wheat Improvement Flagship Program, National Research Council of Canada, Saskatoon, Saskatchewan, SK S7N 0W9, Canada
| | - Adrian J Cutler
- Wheat Improvement Flagship Program, National Research Council of Canada, Saskatoon, Saskatchewan, SK S7N 0W9, Canada
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7
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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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8
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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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9
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Zhang Z, Wang W, Li W. Genetic interactions underlying the biosynthesis and inhibition of β-diketones in wheat and their impact on glaucousness and cuticle permeability. PLoS One 2013; 8:e54129. [PMID: 23349804 PMCID: PMC3547958 DOI: 10.1371/journal.pone.0054129] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 12/06/2012] [Indexed: 01/27/2023] Open
Abstract
Cuticular wax composition greatly impacts plant responses to dehydration. Two parallel pathways exist in Triticeae for manipulating wax composition: the acyl elongation, reduction, and decarbonylation pathway that is active at the vegetative stage and yields primary alcohols and alkanes, and the β-diketone pathway that predominates at the reproductive stage and synthesizes β-diketones. Variation in glaucousness during the reproductive stage of wheat is mainly controlled by the wax production genes, W1 and W2, and wax inhibitor genes, Iw1 and Iw2. Little is known about the metabolic and physiological effects of the genetic interactions among these genes and their roles in shifting wax composition during plant development. We characterized the effect of W1, W2, Iw1, and Iw2 and analyzed their interaction using a set of six near-isogenic lines (NILs) by metabolic, molecular and physiological approaches. Loss of functional alleles of both W genes or the presence of either Iw gene depletes β-diketones and results in the nonglaucous phenotype. Elimination of β-diketones is compensated for by an increase in aldehydes and primary alcohols in the Iw NILs. Accordingly, transcription of CER4-6, which encodes an alcohol-forming fatty acyl-CoA reductase, was elevated 120-fold in iw1Iw2. CER4-6 was transcribed at much higher levels in seedlings than in adult plants, and showed little difference between the glaucous and nonglaucous NILs, suggesting that Iw2 counteracts the developmental repression of CER4-6 at the reproductive stage. While W1 and W2 redundantly function in β-diketone biosynthesis, a combination of both functional alleles led to the β-diketone hydroxylation. Consistent with this, transcription of MAH1-9, which encodes a mid-chain alkane hydroxylase, increased seven-fold only in W1W2. In parallel with the hydroxyl-β-diketone production patterns, glaucousness was intensified and cuticle permeability was reduced significantly in W1W2 compared to the other NILs. This suggests that both W1 and W2 are required for enhancing drought tolerance.
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Affiliation(s)
- Zhengzhi Zhang
- Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota, United States of America
| | - Wei Wang
- Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota, United States of America
| | - Wanlong Li
- Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota, United States of America
- Department of Plant Science, South Dakota State University, Brookings, South Dakota, United States of America
- * E-mail:
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10
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Genetic fine-structure of the GA-1 locus in the higher plant Arabidopsis thaliana (L.) Heynh. Genet Res (Camb) 2009. [DOI: 10.1017/s0016672300021066] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SUMMARYNon-germinating gibberellin (GA) responsive mutants are a powerful tool to study genetic fine structure in higher plants. Nine alleles (EMS-and fast neutron-induced) of the ga-1 locus of Arabidopsis thaliana were tested in a complete half-diallel. No wild type ‘recombinants’ were found in the selfed progeny of 9 homoallelic combinations (in total 3 × 105 plants); in the progenies from the 36 selfed hetero allelics the wild type frequency ranged from zero to 6·6 × 10−4. These frequencies allowed the construction of an internally consistent map for five different sites representing eight alleles. The ninth allele covered three sites and thus behaved like an intragenic deletion. The estimate of the total genetic length of the ga-1 locus was 0·07 cM. The order of the sites was also clearly reflected by the association with proximal outside markers. On the assumption that wild type gametes predominantly arise from reciprocal events, it was shown that a cross-over within the ga-1 locus leads to positive interference in the adjacent region.The results are discussed with respect to the mutagen used, the frequencies found in other plant and Drosophila genes, and the possible occurrence of gene conversion.
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von Wettstein-Knowles P. Analyses of barley spike mutant waxes identify alkenes, cyclopropanes and internally branched alkanes with dominating isomers at carbon 9. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 49:250-64. [PMID: 17241448 DOI: 10.1111/j.1365-313x.2006.02956.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
About 15% of the epidermal wax on Hordeum vulgare cv. Bonus barley spikes is n-alkanes. Longer homologues are greatly reduced in the eceriferum mutants, cer-a(6), cer-e(8), cer-n(26), cer-n(53), cer-n(985), cer-x(60), cer-yc(135) and cer-yl(187). Simultaneously hydrocarbons accounting for only traces in the wild-type become prominent in the mutants, although their chain-length distributions remain unchanged. Accordingly several new hydrocarbon series were identified. The two major ones were C(23)-C(35)cis monoenoic alkenes (the major 9-ene isomer was part of a homologous series including 11, 13 and 15-enes), and the novel C(27)-C(31) cyclopropanes (the ring carbons of major isomers were 9,10 and 11,12 with lesser amounts of 13,14). Three minor series included 2- and 3-methylalkanes plus C(25)-C(33) internally branched alkanes (methyls on carbons 9, 11, 13, 15 or 17; shorter homologues dominated by the 9 isomer, longer homologues by 11, 13 or 15 isomers). Acyl chains destined for spike waxes are synthesized via acyl and polyketide elongase systems plus associated reductive and decarbonylative/decarboxylative enzyme systems. Both elongation systems are defective in synthesizing C(32) acyl chains in all nine mutants. The similarities in the position of the chemical groups (primarily on carbon 9, secondarily on carbon 11) of the alkenes, cyclopropanes and internally branched methyl alkanes imply an origin from a common, hitherto unrecognized associated pathway in barley, designated the enoic pathway. The elongation system leading to the enoic derived hydrocarbons differs from the known elongation systems by inclusion of a mechanism for introducing a double bond.
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Affiliation(s)
- Penny von Wettstein-Knowles
- Department of Genetics, Institute of Molecular Biology and Physiology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
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Abstract
The aerial surfaces of plants are covered with a wax layer that is primarily a waterproof barrier but that also provides protection against environmental stresses. The ubiquitous presence of cuticular wax is testimony to its essential function. Genetic and environmental factors influence wax quantity and composition, which suggests that it is an actively regulated process. The basic biochemistry of wax production has been elucidated over the past three decades; however, we still know very little about its regulation. This review presents a discussion along with new perspectives on the regulatory aspects of wax biosynthesis. Among the topics discussed are the partitioning of fatty acid precursors into wax biosynthesis and the elongation of fatty acids with particular emphasis on the nature of the acyl primer, and the role of ATP in fatty acid elongation. The recent cloning of wax biosynthetic genes and the transport of wax to plant surfaces are also discussed.
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Biosynthesis of esterified alkan-2-ols and β-diketones in barley spike epicuticular wax: Synthesis of radioactive intermediates. ACTA ACUST UNITED AC 1984. [DOI: 10.1007/bf02907782] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nonan-2-ol esters in sorghum leaf epicuticular wax and their collection by preparative gas chromatography. ACTA ACUST UNITED AC 1984. [DOI: 10.1007/bf02907493] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Phenotypic diversity of barley spike waxes resulting from mutations at locuscer-n. ACTA ACUST UNITED AC 1983. [DOI: 10.1007/bf02911915] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Lundqvist U, Von Wettstein-Knowles P. Dominant mutations atCer-yy change barley spike wax into leaf blade wax. ACTA ACUST UNITED AC 1982. [DOI: 10.1007/bf02907795] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Structure of epicuticular waxes on spikes and leaf sheaths of barley as revealed by a direct platinum replica technique. ACTA ACUST UNITED AC 1980. [DOI: 10.1007/bf02932920] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Effect of inhibitors on synthesis of fatty acyl chains present in waxes on developing maize leaves. ACTA ACUST UNITED AC 1980. [DOI: 10.1007/bf02906182] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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