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National audience; Main scientific interest, principles and procedures of organisation of numerized ‘data-base’ as 'source of knowledges' were critically described in the special issue of « Cellulose Chemistry and Technology, 2006, 40 (9-10) : 685-690 » focussed on lignin and plant cell walls chemistry and technology, outlined by some glance on the emergence of scientific concepts in the cases of cellulose, lignin and plants cell wall chemistry. A free public acces of this paper in Prodinra, is paper is freely at « http://prodinra.inra.fr/record/32691 ». The corresponding practical organisation of the related sets of electronic files as ‘documentary recollection’, named ReDoc for ‘Recueil documentaire’ in French, developed at INRA are illustrated here in one of the complete four specific domains 'C', biological chemistry, of the ReDoc data base.

National audience; This 'e-book' ‘LIGNIN’, 537 pages, complete the file ‘Les polymères végétaux - Lignin - Vol. 2- part 1’ at disposal at the site ProdINRA since 2008 (6 chapter,# 200 pages of the book published in 1981 in French with and s et 16 reviews,# 300 pages in English until 2007). This update mainly done by seminars slide-shows images, # 70 pages, concern :1 The principles and practice of construction of the documentary compendium ReDoc tracing an history oh the ideas on ‘The lignin’, 2: the possibility to applied these past, present data to analyse and optimise, foresee, some future concerted chemical uses of lignins and related ligno- cellulosic products, 3: the elementary, physico- chemical, mechanisms liable to affect the spatio- temporal self- organization, lignification, of lignins in these products at macromolecular level ; a short note, 5 pages in ‘Presentation’, provides some references, as significative examples, on these three topics. Two hypertext network cycles starting from the covert allow brief visits through this ‘knowledge base’ (also possible with help of the ‘search tool’. This e-book is constructed according to the ReDoc documentary compendium processes described in one review and a slide-show.; Ce ‘livrel’ ‘LIGNIN’, 537 pages, complète le fichier ‘Les polymères végétaux - Lignin - Vol. 2- part 1’ mis à disposition sur le site ProdINRA en 2008 (6 chapitres,# 200 pages du livre publié en 1981 en français avec 16 revues,# 300 pages en anglais jusqu’en 2007). La mise à jour est faite à partir de suites de diapositives, # 70 pages, présentées lors de séminaires concernant 1 : les principes et pratiques de construction des recueils documentaires ReDoc relatant l’évolution des idées de recherches sur ‘La lignine’, 2 : la possibilité d’employer ces données, présentes et passées pour analyser et optimiser, prévoir, de futurs usages concertés des lignines et produits ligno- cellulosiques, 3 : les mécanismes élémentaires, physico-chimiques, susceptibles d’affecter l’auto- organisation spatio-temporelle, lignification, des macromolécules de lignines dans ces produits ; une brève note, 5 pages en ‘Présentation’, comporte en références quelques articles, exemples significatifs plus récents, sur ces trois thèmes. Deux cycles en réseau de liens hypertexte établis à partir de ces données, permettent de visiter cette base de connaissances, aussi faisable via le moteur de recherche. Ce livrel est construit selon le procédé des Recueils Documentaires, ReDoc, décrit dans l’une des revues et un diaporama.

Part 2 : Ce livrel (40 Mo, pdf) fournit les bases documentaires complémentaires annoncées dans la 'part 1' du Second volume de 'LES POLYMÈRES VÉGÉTAUX'. Il est composé de 1 : listes de références (500 pages), standardisées classées en 60 thèmes pour 4 domaines et ciblées sur l’usage et l’organisation chimiques, biologiques et supramoléculaires des lignines dans les parois végétales, bois, pailles et produits dérivés industriels (papiers, fibres cellulosiques ....) complétant celle de 16 revues et diaporamas publiées entre 1981 et 2007 (300 p.) 2 : de didacticiels en anglais et en français, diaporamas et présentations des procédures de Recueil Documentaire ReDoc (150 p.) illustrés par des extraits de fichiers spécifiques ReDoc (50 p.). Un réseau de cycles hypertextes, établi sur tout le fichier, guide sa visite en tant que 'base de connaissances' alors qu'une exploration libre de la totalité des références, 8.000 au moins, est directement praticable via les outils informatiques standards de recherche. L’ensemble de ce Second volume fournit enfin des éléments pratiques permettant d’évaluer plus exactement l’utilité relative des modes de publications 'numériques' et 'papier' envisagés déjà ici (revue n° 5)., Part 2 : This e-book (40 Mo,pdf) provides the announced complementary documentary bases to the 'part 1' of the Second volume of 'LES POLYMÈRES VÉGÉTAUX'. It consists in 1: standardized references lists, filed in 60 themes of 4 domains and focussed on the uses and the chemical, biological and supramolecular organisation of lignins in plant cell wall, wood, straw and related industrial products (paper, cellulosic fibres ...) complementing those of the 16 reviews (300 p.) published from 1981 to 2007, 2 tutorials in french and english, slide-shows and presentations of the documentary recollection ReDoc processes also illustrated with typical ReDoc file extracts (50 p.). A network of hypertext cycles is settled upon the whole e-book as guide of survey when free researches on the whole references, 8,000 at least, are directly carried via current computer tools. This Second volume, as a whole, finally provides some practical elements allowing a more exact assessment of the relative current profitability of 'numeric' versus 'paper' publication modes soon considered here (review n° 5).

Part 1: Ce ‘livrel’ (36 Mo, pdf) est la mise à jour informatique du livre 'Les polymères végétaux', imprimé en 1981 par Dunod-Gauthier- Villars et actuellement épuisé. Il en comporte les copies, avec autorisation d’éditeurs, de six chapitres (200 pages en français) concernant les composés polyphénoliques polymères, lignines et tanins: propriétés biologiques et chimiques. La mise à jour est faite par copies de 16 revues et deux diaporamas publiés jusqu’en 2007 (350 pages en anglais) ciblés sur l’usage et l’organisation biologiques et supramoléculaires des lignines dans les parois végétales, bois et pailles et les produits dérivés industriels : papiers, fibres cellulosiques. Un réseau de liens hypertexte établi à partir de ces données permet de visiter cette base de connaissances via des moteurs de recherche. Ce livrel est construit selon le procédé des Recueils Documentaires, ReDoc, plus détaillé dans la 'part 2' de ce Second volume., Part 1 : This 'e-book' (36 Mo, PDF) is a computer update of the book 'Les polymères végétaux' printed in 1981 by Dunod-Gauthier- Villars, now out of print. It contains copies, authorized by publisher, of six chapters (200 pages in french) regarding phenolic polymer compounds, lignins and tannins: chemical and biological properties. Updating is provided by 16 reviews and 2 slide-shows published until 2007 (350 pages) focussed on the uses and the biological and supra molecular organisation of lignins in plant cell walls, woods, straws and related industrial products: paper, cellulosic fibres. A hypertext network starting from these data allows visits through this ‘knowledge base’ with help of search engines. This e-book is constructed according to the ReDoc documentary compendium processes more itemized in the part 2 of the Second volume.

International audience; The role of the ‘peroxidase-oxidase’ reaction (catalytic formation of H2O2 by O2 activation), now well-known but seldom discussed, is recalled with respect to biochemical studies on lignin polymerisation and emphasis on the physico-chemical mechanisms of pattern formation and of molecular organisation during the synthesis of lignin model compounds (DHP). The corresponding processes of supramolecular assembly involving oligolignols interactions are related to more fundamental kinetic and thermodynamic mechanisms of cooperative inter- and intra-molecular binding reactions of polymer ligands, through interfacial- and template-constrained polymerisation. Finally, viewing synthetic and natural lignified structures as ‘open systems far from equilibrium’, typically self-organized by nucleation processes and by the formation of ‘dissipative structures’, as previously illustrated in this journal (Cellulose Chem. Technol., 2005, 39, pp. 341-367), the so-called ‘random’ process of lignification is tentatively described in terms of intra- and intermolecular cooperative non-covalent and covalent ‘binding’ and of hydrophobic ‘solvatation’. Here, the somehow controversial word ‘random’ refers to the pre-existence of elementary (i.e. atomic, molecular and polymer) structured building-blocks and to the absence of pre-formed systemic (i.e. supramolecular assemblies) organization.

International audience; At first, the three current questions on the ‘transmission of knowledge’, what, how and why to transmit, are reviewed recalling the emergence and evolution of the concepts of ‘cellulose’ and ‘lignin’, devised more than one century ago as ‘chemical compounds’ and now currently perceived as ‘bio-polymer-structures’ or ‘macromolecular self-organized systems’. Avoiding any contemporary controversy, it is then suggested that such challenging questions would result from both 1/ the difficulty to explain ‘new’ specific concepts by using ‘old’ generic ‘words’ as illustrated with reference to recent ‘modern’ papers, as well as from 2/ the lack of extended studies of the ‘recent and old literature’, mainly due to the difficulty of extensively explore, in a limited period of time, an ever increasing number of more and more specialized publications in different thematic domains-journals. Finally, some principles and practices of organizing and editing specialized ‘data- and knowledge-bases’ are thus recalled and discussed in relation to the new possibilities, trusts and fears, of 'electronic edition' based on assembling electronic files as 'e-base', according to an original procedure of Documentary Recollection, ‘ReDoc’, very recently adapted at INRA.

National audience; This review is strictly focussed oil macromolecular chemistry views concerning the relations between the molecular structure of lignins. the possible self-organisation of lignin networks during plant cell walls lignification and the mechanical properties of woody plants and of their related products (pulp and papers, wood as composite material). Recent advances in genetic manipulations and biotechnological improvement of lignification cell walls and related products is emphasized as introduction. Then, the molecular organisation of lignins, the supramolecular aspects of lignification and, finally, some mechanisms of chemical morphogenesis and biomimetic synthesis are reviewed. A spatial-temporal model, combining activation and inhibition effects, is proposed to account the formation of lignin clusters observed during in situ lignification and in vitro synthesis of lignin polymers (DHP). This model and the corresponding molecular organisation hypothesis are discussed in relation to the so called 'self-organisation' effects, as depending on the cooperative interactions between cell wall components, including water, on autocatalytic initiation of lignin polymerisation by peroxidases, and on some physical and chemical intermolecular chain arrangement and rearrangement observed or suggested to occur during chemical pulping and mechanical deformation of wood. An English translation of this paper, more exactly expressed here in French, is in preparation for 'Internet open access', as the last of three reviews concerning the 'biological variability the states and processes of lignification' and the corresponding 'mechanical behaviour of woody plants and products'.

International audience

The effects of heat treatments used to dry alfalfa stems were investigated. Heating at 70 or 100 °C caused no major change in the cell wall composition, but xylanase had lower activity on the cell wall of heated material and the amount of xylose released varied with the temperature used. Chemical fractionation of cell wall carbohydrates showed that the main changes occurring during stem dehydration concerned pectic polymers and probably hemicelluloses. There was less material soluble in ammonium oxalate from alfalfa heated at 100 °C than from fresh alfalfa. The results suggest that heat processing causes some changes in the cell wall network. Environmental scanning electron microscopy was used to examine fully hydrated tissues at high resolution. There was cell distortion without disruption of cell walls as water was lost.

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Module d'approfondissement de biologie. 1ère année INAPG. Département SIAB*INRA, Centre de Grignon Diffusion du document : INRA, Centre de Grignon

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International audience; The effects of the maize brown-midrib genes bm3 and bm1 on feeding value and agronomic traits were investigated by animal studies and biochemical approaches. When sheep were fed bm3 silage, an increase in digestibility was observed, equal to 2.4 points for digestibility of organic matter (DOM), and 8.1 points for digestibility of crude fiber (DCF). Phenotypic variation was reduced for all observed traits of bm3 hybrids. This allowed the assumption that the bm3 gene acted by levelling to a similar value of almost 74% DOM, quite independently of the original value of the normal counterpart. The bm1 hybrids were intermediate between normal and bm3 ones for DOM, DCF and intake, but the dry matter yield was not reduced for bm1 hybrids. From experiments with young bulls, feed efficiency of INRA260 bm1 was not significantly improved, compared with normal INRA260, but INRA260 bm3 was a lot more efficient. Despite its lower adverse effect on agronomic characteristics of hybrids, the bm1 allele did not appear to be of any interest in improving the silage maize feed efficiency. Variations for lignin content due to the bm3 gene was similar for the 3 hybrids studied, despite their variation for susceptibility to root and stalk lodging. Ratios and content of alkali-labile hydroxycinnamic acids behaved similarly for the 3 hybrids, with a low yield of para-coumaric acid. Structural studies of lignin, after thioacidolysis, strengthened the results previously obtained, with a clear decrease of syringyl units, and the occurrence of the 5-hydroxyguaiacyl residue. The lignin of bm3 genotypes also appeared as a more condensed polymer than that of the normal types. The decrease of lignin content was observed in only 1 bm1 hybrid and appeared the same between normal and bm1 hybrids as between normal and bm3 hybrids. The lower yield of para-coumaric acid, and the equal yield of ferulic acid after alkaline hydrolysis of bm1 material were in good agreement with previous work. After thioacidolysis, the release of monomeric syringyl units was similar between bm1 and bm3, about 30% of the normal counterpart. However, it was very different for guaiacyl units, with a large decrease of the release of these units from the bm1 hybrid. The ratio between syringyl and guaiacyl units was about 0.3 for bm3 hybrids and about 1.3 for the bm1 hybrid. The lignin of this bm1 hybrid appeared as a very condensed polymer compared with the normal type. A large variation for digestibility was also found among normal hybrids. However, inbred lines inducing high digestibility often included unfavorable agronomic traits, such as poor yield, susceptibility to lodging or stalk rot. Second or third cycle lines following pedigree breeding might combine all traits, even if stalk standability and stalk digestibility are partly antagonistic. This method may be considered as easier than the bm3 method, but at present, the 2 ways are probably complementary, and worth investigating for improving silage digestibility, and simultaneously increasing knowledge on silage maize digestibility.; Les effets des gènes brown-midrib bm1 et bm3 sur la valeur alimentaire et les caractéristiques agronomiques d’hybrides de maïs ont été étudiés à partir d’essais sur animaux et de mesures de composition biochimique de la lignine. Sur moutons, les hybrides bm3 conduisent à une amélioration moyenne de la digestibilité de la matière organique (DOM) voisine de 2,4 et de celle de la cellulose brute (DCF) voisine de 8,1 points. La variabilité phénotypique est nettement réduite entre hybrides bm3, comparée à celle observée pour les quasi isogéniques normaux, pour la quasi-totalité des caractères étudiés. En particulier, il semble que la présence du gène bm3 conduise à augmenter la DOM des hybrides à une valeur proche de 74%, quel que soit le niveau de digestibilité de l’hybride normal de départ. Les hybrides bm1 se situent de façon intermédiaire entre les formes normales et bm3, sauf pour la productivité en biomasse qui est équivalente à celle des normaux. Mais des essais de croissance comparée de taurillons nourris avec des ensilages de maïs INRA260, INRA260 bm1 et INRA260 bm3 montrent que la forme bm1 ne permet pas, contrairement à la forme bm3, une amélioration notable des performances animales. La réduction de teneur en lignine a été semblable pour les 3 hybrides bm3 étudiés, alors que ces hybrides présentaient des différences importantes de sensibilité à la verse ou à la casse. Les teneurs et rapports entre acides hydroxycinnamiques libérés après hydrolyse alcaline étaient semblables chez les 3 hybrides, avec une libération faible d’acide para-coumarique caractéristique des génotypes bm3. La thioacydolyse confirme que la lignine des plantes bm3 est plus pauvre en unités syringyl, avec, de plus, la présence d’une unité 5-hydroxyguaiacyl. La lignine des plantes bm3 est un polymère plus condensé que la lignine des plantes normales. Observée à partir d’un seul hybride bm1, la diminution de la teneur en lignine a été semblable chez les plantes bm1 et bm3. Après thioacidolyse, la libération d’unités syringyl était équivalente entre bm1 et bm3. Mais la libération d’unité guaiacyl était beaucoup plus faible pour la lignine des plantes bm 1, avec des rapports syringyl/guaiacyl voisins de 0,3 pour les bm3 et de 1,3 pour les bm1. La lignine des plantes bm1 est également un polymère hautement condensé. Une variabilité importante pour la DOM et la DCF existe aussi entre hybrides normaux. Toutefois, les hybrides les plus digestibles présentent en général des défauts agronomiques importants, qu’il sera sans doute possible de corriger au niveau de lignées de second ou troisième cycle. Actuellement, on peut considérer que les voies normales et bm3 sont deux approches complémentaires de l’amélioration et de la compréhension de la digestibilité du maïs ensilage.

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Cours du DEA de nutrition "Aspects moléculaires et cellulaires". Option "Nutrition Animale". Institut National Agronomique Paris-Grignon. Département des Sciences Animales. (18-29 Avril 1994)*INRA, Centre de Grignon Diffusion du document : INRA, Centre de Grignon

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