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Author

Marie Baucher

Bio: Marie Baucher is an academic researcher from Université libre de Bruxelles. The author has contributed to research in topics: Lignin & Cinnamyl-alcohol dehydrogenase. The author has an hindex of 20, co-authored 68 publications receiving 3412 citations. Previous affiliations of Marie Baucher include Institut national de la recherche agronomique & Ghent University.


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Journal ArticleDOI
TL;DR: Populus is presented as a model system for the study of wood formation and high-resolution analysis of auxin distribution across cambial region tissues suggests that auxin provides positional information for the exit of cells from the meristem and probably also for the duration of cell expansion.
Abstract: Populus is presented as a model system for the study of wood formation (xylogenesis). The formation of wood (secondary xylem) is an ordered developmental process involving cell division, cell expansion, secondary wall deposition, lignification and programmed cell death. Because wood is formed in a variable environment and subject to developmental control, xylem cells are produced that differ in size, shape, cell wall structure, texture and composition. Hormones mediate some of the variability observed and control the process of xylogenesis. High-resolution analysis of auxin distribution across cambial region tissues, combined with the analysis of transgenic plants with modified auxin distribution, suggests that auxin provides positional information for the exit of cells from the meristem and probably also for the duration of cell expansion. Poplar sequencing projects have provided access to genes involved in cell wall formation. Genes involved in the biosynthesis of the carbohydrate skeleton of the cell wall are briefly reviewed. Most progress has been made in characterizing pectin methyl esterases that modify pectins in the cambial region. Specific expression patterns have also been found for expansins, xyloglucan endotransglycosylases and cellulose synthases, pointing to their role in wood cell wall formation and modification. Finally, by studying transgenic plants modified in various steps of the monolignol biosynthetic pathway and by localizing the expression of various enzymes, new insight into the lignin biosynthesis in planta has been gained.

466 citations

Journal ArticleDOI
TL;DR: Progress in the knowledge of the lignin biosynthesis pathway has been obtained and it is now clear that the pathway is more complex than initially thought and there is evidence for alternative pathways.
Abstract: Lignin, a complex heteropolymer of cinnamyl alcohols, is, second to cellulose, the most abundant biopolymer on Earth. Lignification has played a determining role in the adaptation of plants to terrestrial life. As all extracellular polymers, lignin confers rheological properties to plant tissues and participates probably in many other functions in cell and tissue physiology or in cell-to-cell communication. Economically, lignin is very important because it determines wood quality and it affects the pulp and paper-making processes as well as the digestibility of forage crops. For all these reasons the lignin biosynthesis pathway has been the subject of many studies. At present, most genes encoding the enzymes involved in the biosynthesis of lignin have been cloned and characterized. Various recent studies report on the alteration of the expression of these genes by genetic engineering, yielding plants with modified lignin. In addition, several mutants have been analyzed with changes in lignin content or lignin composition resulting in altered properties. Thanks to these studies, progress in the knowledge of the lignin biosynthesis pathway has been obtained. It is now clear that the pathway is more complex than initially thought and there is evidence for alternative pathways. A fine manipulation of the lignin content and/or composition in plants is now achievable and could have important economical and environmental benefits.

390 citations

Journal ArticleDOI
TL;DR: The results indicate that reducing the CAD activity in trees might be a valuable strategy to optimize certain processes of the wood industry, especially those of the pulp and paper industry.
Abstract: Cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in the biosynthesis of the lignin precursors, the monolignols. We have down-regulated CAD in transgenic poplar (Populus tremula X Populus alba) by both antisense and co-suppression strategies. Several antisense and sense CAD transgenic poplars had an approximately 70% reduced CAD activity that was associated with a red coloration of the xylem tissue. Neither the lignin amount nor the lignin monomeric composition (syringyl/guaiacyl) were significantly modified. However, phloroglucinol-HCl staining was different in the down-regulated CAD plants, suggesting changes in the number of aldehyde units in the lignin. Furthermore, the reactivity of the cell wall toward alkali treatment was altered: a lower amount of lignin was found in the insoluble, saponified residue and more lignin could be precipitated from the soluble alkali fraction. Moreover, large amounts of phenolic compounds, vanillin and especially syringaldehyde, were detected in the soluble alkali fraction of the CAD down-regulated poplars. Alkaline pulping experiments on 3-month-old trees showed a reduction of the kappa number without affecting the degree of cellulose degradation. These results indicate that reducing the CAD activity in trees might be a valuable strategy to optimize certain processes of the wood industry, especially those of the pulp and paper industry.

364 citations

Journal ArticleDOI
TL;DR: How genetic engineering has yielded new insights into how the lignin biosynthetic pathway operates is described and it is demonstrated that lignIn can be improved to facilitate pulping.
Abstract: Lignin is a major component of wood, the most widely used raw material for the production of pulp and paper. Although the biochemistry and molecular biology underpinning lignin production are better understood than they are for the other wood components, recent work has prompted a number of re-evaluations of the lignin biosynthetic pathway. Some of the work on which these revisions have been based involved the investigation of transgenic plants with modified lignin biosynthesis. In addition to their value in elucidating the lignin biosynthetic pathway, such transgenic plants are also being produced with the aim of improving plant raw materials for pulp and paper production. This review describes how genetic engineering has yielded new insights into how the lignin biosynthetic pathway operates and demonstrates that lignin can be improved to facilitate pulping. The current technologies used to produce paper are presented in this review, followed by a discussion of the impact of lignin modification on pulp production. Fine-tuned modification of lignin content, composition, or both is now achievable and could have important economic and environmental benefits.

349 citations

Journal ArticleDOI
TL;DR: Although the lignin composition was consistently modified, theLignin content of the transgenic poplars was similar to that of the controls, and a similar phenotype was observed in brown-midrib mutants of maize and sorghum, known for their altered lignification.
Abstract: Summary Lignin is a polymeric constituent of the cell wall that needs to be removed during the paper making process. Bi-specific caffeic acid/5-hydroxyferulic acid O-methyltransferase (COMT) catalyses the O-methylation of caffeic acid and 5-hydroxyferulic acid to ferulic acid and sinapic acid, respectively. These compounds are intermediates in the biosynthesis of the lignin precursors. Therefore, COMTs are potential target enzymes for reducing the amount, or modifying the composition, of lignin in plants. Different antisense and sense constructs have been expressed of a gene encoding a COMT from poplar (Populus trichocarpa x P. deltoides) in a P. tremula x P. alba clone under the control of the cauliflower mosaic virus 35S promoter. From all analysed transformants, four lines transformed with an antisense construct had a reduced COMT activity. Two showed a 50% reduction of COMT activity, which altered only slightly the monomeric composition. In the two other transformants, the COMT activity was reduced by 95%. In the latter case, the syringyl/ guaiacyl ratio (S/G) was reduced by sixfold (due to a decrease of S and an increase of G), as analysed by thioacidolysis. A new component of lignin, the 5-hydroxyguaiacyl residue, was detected among the thioacidolysis products. Moreover, in contrast to the white/yellow colour of wild-type wood, the xylem of the transgenic lines with a 95% reduction of COMT activity was pale rose. A similar phenotype was observed in brown-midrib mutants of maize and sorghum, known for their altered lignification. Although the lignin composition was consistently modified, the lignin content of the transgenic poplars was similar to that of the controls.

276 citations


Cited by
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Journal ArticleDOI
Gerald A. Tuskan1, Gerald A. Tuskan2, Stephen P. DiFazio3, Stephen P. DiFazio2, Stefan Jansson4, Joerg Bohlmann5, Igor V. Grigoriev6, Uffe Hellsten6, Nicholas H. Putnam6, Steven G. Ralph5, Stephane Rombauts7, Asaf Salamov6, Jacquie Schein, Lieven Sterck7, Andrea Aerts6, Rishikeshi Bhalerao4, Rishikesh P. Bhalerao8, Damien Blaudez9, Wout Boerjan7, Annick Brun9, Amy M. Brunner10, Victor Busov11, Malcolm M. Campbell12, John E. Carlson13, Michel Chalot9, Jarrod Chapman6, G.-L. Chen2, Dawn Cooper5, Pedro M. Coutinho14, Jérémy Couturier9, Sarah F. Covert15, Quentin C. B. Cronk5, R. Cunningham2, John M. Davis16, Sven Degroeve7, Annabelle Déjardin9, Claude W. dePamphilis13, John C. Detter6, Bill Dirks17, Inna Dubchak6, Inna Dubchak18, Sébastien Duplessis9, Jürgen Ehlting5, Brian E. Ellis5, Karla C Gendler19, David Goodstein6, Michael Gribskov20, Jane Grimwood21, Andrew Groover22, Lee E. Gunter2, Björn Hamberger5, Berthold Heinze, Yrjö Helariutta23, Yrjö Helariutta8, Yrjö Helariutta24, Bernard Henrissat14, D. Holligan15, Robert A. Holt, Wenyu Huang6, N. Islam-Faridi22, Steven J.M. Jones, M. Jones-Rhoades25, Richard A. Jorgensen19, Chandrashekhar P. Joshi11, Jaakko Kangasjärvi23, Jan Karlsson4, Colin T. Kelleher5, Robert Kirkpatrick, Matias Kirst16, Annegret Kohler9, Udaya C. Kalluri2, Frank W. Larimer2, Jim Leebens-Mack15, Jean-Charles Leplé9, Philip F. LoCascio2, Y. Lou6, Susan Lucas6, Francis Martin9, Barbara Montanini9, Carolyn A. Napoli19, David R. Nelson26, C D Nelson22, Kaisa Nieminen23, Ove Nilsson8, V. Pereda9, Gary F. Peter16, Ryan N. Philippe5, Gilles Pilate9, Alexander Poliakov18, J. Razumovskaya2, Paul G. Richardson6, Cécile Rinaldi9, Kermit Ritland5, Pierre Rouzé7, D. Ryaboy18, Jeremy Schmutz21, J. Schrader27, Bo Segerman4, H. Shin, Asim Siddiqui, Fredrik Sterky, Astrid Terry6, Chung-Jui Tsai11, Edward C. Uberbacher2, Per Unneberg, Jorma Vahala23, Kerr Wall13, Susan R. Wessler15, Guojun Yang15, T. Yin2, Carl J. Douglas5, Marco A. Marra, Göran Sandberg8, Y. Van de Peer7, Daniel S. Rokhsar6, Daniel S. Rokhsar17 
15 Sep 2006-Science
TL;DR: The draft genome of the black cottonwood tree, Populus trichocarpa, has been reported in this paper, with more than 45,000 putative protein-coding genes identified.
Abstract: We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.

4,025 citations

Journal ArticleDOI
TL;DR: Lignin is the generic term for a large group of aromatic polymers resulting from the oxidative combinatorial coupling of 4-hydroxyphenylpropanoids, deposited predominantly in the walls of secondarily thickened cells, making them lignin-like polymers.
Abstract: Lignin is the generic term for a large group of aromatic polymers resulting from the oxidative combinatorial coupling of 4-hydroxyphenylpropanoids ([Boerjan et al., 2003][1]; [Ralph et al., 2004][2]). These polymers are deposited predominantly in the walls of secondarily thickened cells, making them

1,956 citations

Journal ArticleDOI
Xun Xu1, Shengkai Pan1, Shifeng Cheng1, Bo Zhang1, Mu D1, Peixiang Ni1, Gengyun Zhang1, Shuang Yang1, Ruiqiang Li1, Jun Wang1, Gisella Orjeda2, Frank Guzman2, Torres M2, Roberto Lozano2, Olga Ponce2, Diana Martinez2, De la Cruz G3, Chakrabarti Sk3, Patil Vu3, Konstantin G. Skryabin4, Boris B. Kuznetsov4, Nikolai V. Ravin4, Tatjana V. Kolganova4, Alexey V. Beletsky4, Andrey V. Mardanov4, Di Genova A5, Dan Bolser5, David M. A. Martin5, Li G, Yang Y, Hanhui Kuang6, Hu Q6, Xiong X7, Gerard J. Bishop8, Boris Sagredo, Nilo Mejía, Zagorski W9, Robert Gromadka9, Jan Gawor9, Pawel Szczesny9, Sanwen Huang, Zhang Z, Liang C, He J, Li Y, He Y, Xu J, Youjun Zhang, Xie B, Du Y, Qu D, Merideth Bonierbale10, Marc Ghislain10, Herrera Mdel R, Giovanni Giuliano, Marco Pietrella, Gaetano Perrotta, Paolo Facella, O'Brien K11, Sergio Enrique Feingold, Barreiro Le, Massa Ga, Luis Aníbal Diambra12, Brett R Whitty13, Brieanne Vaillancourt13, Lin H13, Alicia N. Massa13, Geoffroy M13, Lundback S13, Dean DellaPenna13, Buell Cr14, Sanjeev Kumar Sharma14, David Marshall14, Robbie Waugh14, Glenn J. Bryan14, Destefanis M15, Istvan Nagy15, Dan Milbourne15, Susan Thomson16, Mark Fiers16, Jeanne M. E. Jacobs16, Kåre Lehmann Nielsen17, Mads Sønderkær17, Marina Iovene18, Giovana Augusta Torres18, Jiming Jiang18, Richard E. Veilleux19, Christian W. B. Bachem20, de Boer J20, Theo Borm20, Bjorn Kloosterman20, van Eck H20, Erwin Datema20, Hekkert Bt20, Aska Goverse20, van Ham Rc20, Richard G. F. Visser20 
10 Jul 2011-Nature
TL;DR: The potato genome sequence provides a platform for genetic improvement of this vital crop and predicts 39,031 protein-coding genes and presents evidence for at least two genome duplication events indicative of a palaeopolyploid origin.
Abstract: Potato (Solanum tuberosum L.) is the world's most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital crop.

1,813 citations

Journal ArticleDOI
Boulos Chalhoub1, Shengyi Liu2, Isobel A. P. Parkin3, Haibao Tang4, Haibao Tang5, Xiyin Wang6, Julien Chiquet1, Harry Belcram1, Chaobo Tong2, Birgit Samans7, Margot Correa8, Corinne Da Silva8, Jérémy Just1, Cyril Falentin9, Chu Shin Koh10, Isabelle Le Clainche1, Maria Bernard8, Pascal Bento8, Benjamin Noel8, Karine Labadie8, Adriana Alberti8, Mathieu Charles9, Dominique Arnaud1, Hui Guo6, Christian Daviaud, Salman Alamery11, Kamel Jabbari1, Kamel Jabbari12, Meixia Zhao13, Patrick P. Edger14, Houda Chelaifa1, David C. Tack15, Gilles Lassalle9, Imen Mestiri1, Nicolas Schnel9, Marie-Christine Le Paslier9, Guangyi Fan, Victor Renault16, Philippe E. Bayer11, Agnieszka A. Golicz11, Sahana Manoli11, Tae-Ho Lee6, Vinh Ha Dinh Thi1, Smahane Chalabi1, Qiong Hu2, Chuchuan Fan17, Reece Tollenaere11, Yunhai Lu1, Christophe Battail8, Jinxiong Shen17, Christine Sidebottom10, Xinfa Wang2, Aurélie Canaguier1, Aurélie Chauveau9, Aurélie Bérard9, G. Deniot9, Mei Guan18, Zhongsong Liu18, Fengming Sun, Yong Pyo Lim19, Eric Lyons20, Christopher D. Town5, Ian Bancroft21, Xiaowu Wang, Jinling Meng17, Jianxin Ma13, J. Chris Pires22, Graham J.W. King23, Dominique Brunel9, Régine Delourme9, Michel Renard9, Jean-Marc Aury8, Keith L. Adams15, Jacqueline Batley24, Jacqueline Batley11, Rod J. Snowdon7, Jörg Tost, David Edwards11, David Edwards24, Yongming Zhou17, Wei Hua2, Andrew G. Sharpe10, Andrew H. Paterson6, Chunyun Guan18, Patrick Wincker25, Patrick Wincker1, Patrick Wincker8 
22 Aug 2014-Science
TL;DR: The polyploid genome of Brassica napus, which originated from a recent combination of two distinct genomes approximately 7500 years ago and gave rise to the crops of rape oilseed, is sequenced.
Abstract: Oilseed rape (Brassica napus L.) was formed ~7500 years ago by hybridization between B. rapa and B. oleracea, followed by chromosome doubling, a process known as allopolyploidy. Together with more ancient polyploidizations, this conferred an aggregate 72× genome multiplication since the origin of angiosperms and high gene content. We examined the B. napus genome and the consequences of its recent duplication. The constituent An and Cn subgenomes are engaged in subtle structural, functional, and epigenetic cross-talk, with abundant homeologous exchanges. Incipient gene loss and expression divergence have begun. Selection in B. napus oilseed types has accelerated the loss of glucosinolate genes, while preserving expansion of oil biosynthesis genes. These processes provide insights into allopolyploid evolution and its relationship with crop domestication and improvement.

1,743 citations

Journal ArticleDOI
TL;DR: This paper provides a summary of background information and methodologies used for the analysis of phenolics in foods and nutraceuticals.

1,490 citations