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Zengyu Wang - One of the best experts on this subject based on the ideXlab platform.
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Downregulation of Cinnamyl Alcohol Dehydrogenase (CAD) Leads to Improved Saccharification Efficiency in Switchgrass
BioEnergy Research, 2011Co-Authors: Chunxiang Fu, Xirong Xiao, Yajun Xi, Yaxin Ge, Joseph Bouton, Richard A. Dixon, Fang Chen, Zengyu WangAbstract:The bioconversion of carbohydrates in the herbaceous bioenergy crop, switchgrass ( Panicum virgatum L.), is limited by the associated lignins in the biomass. The cinnamyl alcohol Dehydrogenase ( CAD ) gene encodes a key enzyme which catalyzes the last step of lignin monomer biosynthesis. Transgenic switchgrass plants were produced with a CAD RNAi gene construct under the control of the maize ubiquitin promoter. The transgenic lines showed reduced CAD expression levels, reduced enzyme activities, reduced lignin content, and altered lignin composition. The modification of lignin biosynthesis resulted in improved sugar release and forage digestibility. Significant increases of saccharification efficiency were obtained in most of the transgenic lines with or without acid pretreatment. A negative correlation between lignin content and sugar release was found among these transgenic switchgrass lines. The transgenic materials have the potential to allow for improved efficiency of cellulosic ethanol production.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Che, Chungkyoo Auh, Paul Dowling, Jeremey Ell, Andrew Hopkins, Richard A Dixo, Fang Che, Zengyu WangAbstract:Article on improved forage digestibility of tall fescue (Festuca arundinacea) by transgenic down-regulation of cinnamyl alcohol Dehydrogenase.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Chen, Chungkyoo Auh, Paul Dowling, Andrew Hopkins, Richard A. Dixon, Fang Chen, Jeremey Bell, Zengyu WangAbstract:Lignification of cell walls during plant development has been identified as the major factor limiting forage digestibility and concomitantly animal productivity. cDNA sequences encoding a key lignin biosynthetic enzyme, cinnamyl alcohol Dehydrogenase (CAD), were cloned from the widely grown monocotyledonous forage species tall fescue (Festuca arundinacea Schreb.). Recombinant tall fescue CAD expressed in E. coli exhibited the highest V(max)/K(m) values when coniferaldehyde and sinapaldehyde were used as substrates. Transgenic tall fescue plants carrying either sense or antisense CAD gene constructs were obtained by microprojectile bombardment of single genotype-derived embryogenic suspension cells. Severely reduced levels of mRNA transcripts and significantly reduced CAD enzymatic activities were found in two transgenic plants carrying sense and antisense CAD transgenes, respectively. These CAD down-regulated transgenic lines had significantly decreased lignin content and altered ratios of syringyl (S) to guaiacyl (G), G to p-hydroxyphenyl (H) and S to H units. No significant changes in cellulose, hemicellulose, neutral sugar composition, p-coumaric acid and ferulic acid levels were observed in the transgenic plants. Increases of in vitro dry matter digestibility of 7.2-9.5% were achieved in the CAD down-regulated lines, thus providing a novel germplasm to be used for the development of grass cultivars with improved forage quality.
Jacqueline Grima-pettenati - One of the best experts on this subject based on the ideXlab platform.
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Rational inhibitor design, synthesis and NMR spectroscopic study by transferred nuclear overhauser spectroscopy of novel inhibitors of cinnamyl alcohol Dehydrogenase, a critical enzyme in lignification.
Journal of Enzyme Inhibition, 2009Co-Authors: Karen Kennedy, James H. Mckie, Kenneth T. Douglas, Jacqueline Grima-pettenati, Michel Baltas, Hubert Duran, Kevin J. Embrey, Jean Guillaume Giraudon, Liliane GorrichonAbstract:AbstractCinnamyl alcohol Dehydrogenase is one of the enzymes controlling the first two committed steps of lignification. Using a 3-dimensional similarity model of this enzyme, a series of novel phos-phonates (1-5) was designed as potential inhibitors. Phosphonates 1-5 were synthesized in good yield by reaction of the corresponding cinnamaldehydes with tetraethylmethylene diphos-phonate. Monophosphonic acids 6 and 7 were obtained by basic hydrolysis of the corresponding phosphonates while phosphonamidate 8 was synthesized by reacting benzylamine with the iminium salt intermediate of the monophosphonic acid. Using recombinant cinnamyl alcohol Dehydrogenase (CAD, EC 1.1.1.195) the inhibitory activity of these compounds was evaluated and compared with that of the carbonyl analogues. Inhibition kinetic studies showed compounds 2 and 3 to be mixed type linear inhibitors while compound 4 was uncompetitive. H NMR studies of inhibitor 2, for which K1 and K1 were 20 and 86 pM, respectively, in the presence of CAD b...
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Characterisation of caffeic acid O-methyltransferase and cinnamyl alcohol Dehydrogenase gene expression patterns by in situ hybridisation in Eucalyptus gunnii Hook. plantlets
Plant Science, 2003Co-Authors: Simon Hawkins, Alain M. Boudet, Jacqueline Grima-pettenatiAbstract:Abstract The developmental tissue- and cell-specific expression pattern of two ‘lignification’ genes, caffeic acid O -methyltransferase (C-OMT) and cinnamyl alcohol Dehydrogenase (CAD), was analysed by in situ hybridisation in leaf and stem samples of Eucalyptus plantlets. Both genes are expressed, in a coordinated, developmental fashion, in the same cell types—especially developing vessels—of differentiating stem xylem tissue confirming their role in lignification and demonstrating that this process is under strict developmental control. C-OMT, but not CAD, transcripts were also localised to developing xylem vessels in the midribs of leaves. Histochemical analyses revealed that, in stem xylem tissues, C-OMT and CAD are expressed in cells poor in S-type lignin (primary xylem vessels and immature secondary xylem cells) and also in cells that later become rich in S-type lignin (mature secondary xylem cells).
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Rational inhibitor design, synthesis and NMR spectroscopic study by transferred nuclear overhauser spectroscopy of novel inhibitors of cinnamyl alcohol Dehydrogenase, a critical enzyme in lignification.
Journal of enzyme inhibition, 1999Co-Authors: Karen Kennedy, James H. Mckie, Kenneth T. Douglas, Jacqueline Grima-pettenati, Michel Baltas, Hubert Duran, Kevin J. Embrey, Jean Guillaume Giraudon, Liliane GorrichonAbstract:Cinnamyl alcohol Dehydrogenase is one of the enzymes controlling the first two committed steps of lignification. Using a 3-dimensional similarity model of this enzyme, a series of novel phosphonates (1-5) was designed as potential inhibitors. Phosphonates 1-5 were synthesized in good yield by reaction of the corresponding cinnamaldehydes with tetraethylmethylene diphosphonate. Monophosphonic acids 6 and 7 were obtained by basic hydrolysis of the corresponding phosphonates while phosphonamidate 8 was synthesized by reacting benzylamine with the iminium salt intermediate of the monophosphonic acid. Using recombinant cinnamyl alcohol Dehydrogenase (CAD, EC 1.1.1.195) the inhibitory activity of these compounds was evaluated and compared with that of the carbonyl analogues. Inhibition kinetic studies showed compounds 2 and 3 to be mixed type linear inhibitors while compound 4 was uncompetitive. 1H NMR studies of inhibitor 2, for which Ki and Ki' were 20 and 86 microM, respectively, in the presence of CAD based on selective line-broadening showed an increased interaction of the 3-OMe group of the aromatic ring of the inhibitor with the active site of the CAD. A transferred nuclear overhauser effect spectroscopy (TRNOESY) experiment for inhibitor 2 with CAD was used to determine the conformation of this compound bound to CAD. These results were found to be consistent with the 3-dimensional structural model of the enzyme.
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Tissue- and cell-specific expression of a cinnamyl alcohol Dehydrogenase promoter in transgenic poplar plants
Plant Molecular Biology, 1995Co-Authors: Catherine Feuillet, Gilles Pilate, Virginie Lauvergeat, Christine Deswarte, Alain Boudet, Jacqueline Grima-pettenatiAbstract:Cinnamyl alcohol Dehydrogenase (CAD) which catalyses the synthesis of the cinnamyl alcohols, the immediate precursors of lignins, from the corresponding cinnamaldehydes is considered to be a highly specific marker for lignification We have isolated and characterized a CAD genomic clone from eucalyptus, a woody species of economic importance. The full-length promoter ( EuCAD , 2.5 kb) and a series of 5′ deletions were fused to the β-glucuronidase (GUS) reporter gene. These constructs were tested in a homologous transient expression system of eucalyptus protoplasts which enabled the identification of several regions involved in transcriptional control. In order to study the spatial and developmental regulation of the CAD gene, the chimeric gene fusion ( EuCAD-GUS ) was then transferred via Agrobacterium tumefaciens -mediated transformation into poplar, an easily transformable woody angiosperm. Quantitative fluorometric assays conducted on eight independent in vitro transformants showed that GUS activity was highest in roots followed thereafter by stems and leaves. Histochemical staining for GUS activity on both in vitro primary transformants and more mature greenhouse-grown plants indicated a specific expression in the vascular tissues of stems, roots, petioles and leaves. At the onset of xylem differentiation, GUS activity was detected in parenchyma cells differentiating between the xylem-conducting elements. After secondary growth has occurred, GUS activity was localized in xylem ray cells and parenchyma cells surrounding the lignified phloem and sclerenchyma fibers. This first characterization of a woody angiosperm CAD promoter provides functional evidence for the role of CAD in lignification and suggests that parenchyma cells expressing CAD may provide lignin precursors to the adjacent lignified elements (vessels and fibres).
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Purification and characterization of cinnamyl alcohol Dehydrogenase isoforms from Phaseolus vulgaris
Phytochemistry, 1994Co-Authors: Jacqueline Grima-pettenati, Christian Campargue, A. M. Boudet, Alain M. BoudetAbstract:Cinnamyl alcohol Dehydrogenase (CAD) catalyses the reduction of hydroxycinnamaldehydes (p-coumaryl, coniferyl, sinapyl) to the corresponding alcohols which are the monomeric precursors of lignins. We have demonstrated the occurrence of two isoforms of CAD (CAD1 and CAD2) in bean which differ in terms of subunit Mr, specific activity, substrate affinity and antigenicity. The most abundant polypeptide in bean pods, organs with very limited lignification, is a low affinity CAD isoform (CAD1). This enzyme which is distinct from a benzyl alcohol Dehydrogenase with broad substrate specificity, was purified to apparent homogeneity and partial amino acid sequencing was carried out using internal peptides obtained by trypsin cleavage.
Andrew Hopkins - One of the best experts on this subject based on the ideXlab platform.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Che, Chungkyoo Auh, Paul Dowling, Jeremey Ell, Andrew Hopkins, Richard A Dixo, Fang Che, Zengyu WangAbstract:Article on improved forage digestibility of tall fescue (Festuca arundinacea) by transgenic down-regulation of cinnamyl alcohol Dehydrogenase.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Chen, Chungkyoo Auh, Paul Dowling, Andrew Hopkins, Richard A. Dixon, Fang Chen, Jeremey Bell, Zengyu WangAbstract:Lignification of cell walls during plant development has been identified as the major factor limiting forage digestibility and concomitantly animal productivity. cDNA sequences encoding a key lignin biosynthetic enzyme, cinnamyl alcohol Dehydrogenase (CAD), were cloned from the widely grown monocotyledonous forage species tall fescue (Festuca arundinacea Schreb.). Recombinant tall fescue CAD expressed in E. coli exhibited the highest V(max)/K(m) values when coniferaldehyde and sinapaldehyde were used as substrates. Transgenic tall fescue plants carrying either sense or antisense CAD gene constructs were obtained by microprojectile bombardment of single genotype-derived embryogenic suspension cells. Severely reduced levels of mRNA transcripts and significantly reduced CAD enzymatic activities were found in two transgenic plants carrying sense and antisense CAD transgenes, respectively. These CAD down-regulated transgenic lines had significantly decreased lignin content and altered ratios of syringyl (S) to guaiacyl (G), G to p-hydroxyphenyl (H) and S to H units. No significant changes in cellulose, hemicellulose, neutral sugar composition, p-coumaric acid and ferulic acid levels were observed in the transgenic plants. Increases of in vitro dry matter digestibility of 7.2-9.5% were achieved in the CAD down-regulated lines, thus providing a novel germplasm to be used for the development of grass cultivars with improved forage quality.
Chungkyoo Auh - One of the best experts on this subject based on the ideXlab platform.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Che, Chungkyoo Auh, Paul Dowling, Jeremey Ell, Andrew Hopkins, Richard A Dixo, Fang Che, Zengyu WangAbstract:Article on improved forage digestibility of tall fescue (Festuca arundinacea) by transgenic down-regulation of cinnamyl alcohol Dehydrogenase.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Chen, Chungkyoo Auh, Paul Dowling, Andrew Hopkins, Richard A. Dixon, Fang Chen, Jeremey Bell, Zengyu WangAbstract:Lignification of cell walls during plant development has been identified as the major factor limiting forage digestibility and concomitantly animal productivity. cDNA sequences encoding a key lignin biosynthetic enzyme, cinnamyl alcohol Dehydrogenase (CAD), were cloned from the widely grown monocotyledonous forage species tall fescue (Festuca arundinacea Schreb.). Recombinant tall fescue CAD expressed in E. coli exhibited the highest V(max)/K(m) values when coniferaldehyde and sinapaldehyde were used as substrates. Transgenic tall fescue plants carrying either sense or antisense CAD gene constructs were obtained by microprojectile bombardment of single genotype-derived embryogenic suspension cells. Severely reduced levels of mRNA transcripts and significantly reduced CAD enzymatic activities were found in two transgenic plants carrying sense and antisense CAD transgenes, respectively. These CAD down-regulated transgenic lines had significantly decreased lignin content and altered ratios of syringyl (S) to guaiacyl (G), G to p-hydroxyphenyl (H) and S to H units. No significant changes in cellulose, hemicellulose, neutral sugar composition, p-coumaric acid and ferulic acid levels were observed in the transgenic plants. Increases of in vitro dry matter digestibility of 7.2-9.5% were achieved in the CAD down-regulated lines, thus providing a novel germplasm to be used for the development of grass cultivars with improved forage quality.
Paul Dowling - One of the best experts on this subject based on the ideXlab platform.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Che, Chungkyoo Auh, Paul Dowling, Jeremey Ell, Andrew Hopkins, Richard A Dixo, Fang Che, Zengyu WangAbstract:Article on improved forage digestibility of tall fescue (Festuca arundinacea) by transgenic down-regulation of cinnamyl alcohol Dehydrogenase.
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improved forage digestibility of tall fescue festuca arundinacea by transgenic down regulation of cinnamyl alcohol Dehydrogenase
Plant Biotechnology Journal, 2003Co-Authors: Lei Chen, Chungkyoo Auh, Paul Dowling, Andrew Hopkins, Richard A. Dixon, Fang Chen, Jeremey Bell, Zengyu WangAbstract:Lignification of cell walls during plant development has been identified as the major factor limiting forage digestibility and concomitantly animal productivity. cDNA sequences encoding a key lignin biosynthetic enzyme, cinnamyl alcohol Dehydrogenase (CAD), were cloned from the widely grown monocotyledonous forage species tall fescue (Festuca arundinacea Schreb.). Recombinant tall fescue CAD expressed in E. coli exhibited the highest V(max)/K(m) values when coniferaldehyde and sinapaldehyde were used as substrates. Transgenic tall fescue plants carrying either sense or antisense CAD gene constructs were obtained by microprojectile bombardment of single genotype-derived embryogenic suspension cells. Severely reduced levels of mRNA transcripts and significantly reduced CAD enzymatic activities were found in two transgenic plants carrying sense and antisense CAD transgenes, respectively. These CAD down-regulated transgenic lines had significantly decreased lignin content and altered ratios of syringyl (S) to guaiacyl (G), G to p-hydroxyphenyl (H) and S to H units. No significant changes in cellulose, hemicellulose, neutral sugar composition, p-coumaric acid and ferulic acid levels were observed in the transgenic plants. Increases of in vitro dry matter digestibility of 7.2-9.5% were achieved in the CAD down-regulated lines, thus providing a novel germplasm to be used for the development of grass cultivars with improved forage quality.