Chez plusieurs crucifères, deux activités se liant à l'ADNr, NF B et NF D, ont été identifiée... more Chez plusieurs crucifères, deux activités se liant à l'ADNr, NF B et NF D, ont été identifiées interagissant spécifiquement avec une séquence conservée du 5'ETS appelée A123BP. Nous avons caractérisés ces complexes et identifié leurs constituants majeurs. Ainsi, la protéine majeure impliquée dans le complexe constituant NF D correspond à une Nucléoline, tandis qu'une poly(ADP-ribose) polymerase semble être la protéine majeure du complexe correspondant à NF B. La Nucléoline est impliquée dans des nombreux évènements de la biogenèse du ribosome, y compris la régulation de la transcription des gènes ribosomiques. Par contre, aucune implication de la poly(ADP-ribose) polymérase dans la biogenèse du ribosome n'a été décrite jusqu'au présent dans la biogenèse du ribosome. Ainsi donc, nos résultats suggèrent un rôle de NF B et NF D dans la régulation des événements précoces de la biogenèse du ribosome chez les plantes crucifères.PERPIGNAN-BU Sciences (661362101) / Sudoc...
- Regulation of gene expression Number of black and white figures: 6 Number of colour figures: 2 ... more - Regulation of gene expression Number of black and white figures: 6 Number of colour figures: 2 Supplementary material: 2 colour figures and 2 tables
Chez plusieurs cruciferes, deux activites se liant a l'ADNr, NF B et NF D, ont ete identifiee... more Chez plusieurs cruciferes, deux activites se liant a l'ADNr, NF B et NF D, ont ete identifiees interagissant specifiquement avec une sequence conservee du 5'ETS appelee A123BP. Nous avons caracterises ces complexes et identifie leurs constituants majeurs. Ainsi, la proteine majeure impliquee dans le complexe constituant NF D correspond a une Nucleoline, tandis qu'une poly(ADP-ribose) polymerase semble etre la proteine majeure du complexe correspondant a NF B. La Nucleoline est impliquee dans des nombreux evenements de la biogenese du ribosome, y compris la regulation de la transcription des genes ribosomiques. Par contre, aucune implication de la poly(ADP-ribose) polymerase dans la biogenese du ribosome n'a ete decrite jusqu'au present dans la biogenese du ribosome. Ainsi donc, nos resultats suggerent un role de NF B et NF D dans la regulation des evenements precoces de la biogenese du ribosome chez les plantes cruciferes.
Caffeoyl Coenzyme A 3-O-Methyltransferase (CCoAOMT) and Caffeic acid-O-Methyltransferase (COMT) a... more Caffeoyl Coenzyme A 3-O-Methyltransferase (CCoAOMT) and Caffeic acid-O-Methyltransferase (COMT) are key enzymes in the biosynthesis of coniferyl and sinapyl alcohols, the precursors of guaiacyl (G) and syringyl (S) lignin subunits. The function of these enzymes was characterised in single and double mutant maize plants. In this work, we determined that the comt (brown-midrib 3) mutant plants display a reduction of the flavonolignin unit derived from tricin (a dimethylated flavone), demonstrating that COMT is a key enzyme involved in the synthesis of this compound. In contrast, the ccoaomt1 mutants displays wild type amount of tricin, suggesting that CCoAOMT1 is not essential for the synthesis of this compound. Based on our data, we suggest that CCoAOMT1 is involved in lignin biosynthesis at least in midribs. The phenotype of ccoaomt1 mutant plants displays no alterations, and their lignin content and composition remain unchanged. On the other hand, the ccoaomt1 comt mutant displays ...
Lodging is one of the causes of maize (Zea mays L.) production losses worldwide and, at least, th... more Lodging is one of the causes of maize (Zea mays L.) production losses worldwide and, at least, the resistance to stalk lodging has been positively correlated with stalk strength. In order to elucidate the putative relationship between cell wall, stalk strength and lodging resistance, twelve maize inbreds varying in rind penetration strength and lodging resistance were characterized for cell wall composition and structure. Stepwise multiple regression indicates that H lignin subunits confer a greater rind penetration strength. Besides, the predictive model for lodging showed that a high ferulic acid content increases the resistance to lodging, whereas those of diferulates decrease it. These outcomes highlight that the strength and lodging susceptibility of maize stems may be conditioned by structural features of cell wall rather than by the net amount of cellulose, hemicelluloses and lignin. The results presented here provide biotechnological targets in breeding programs aimed at imp...
This is an Accepted Article that has been peer-reviewed and approved for publication in the The P... more This is an Accepted Article that has been peer-reviewed and approved for publication in the The Plant Journal, but has yet to undergo copy-editing and proof correction. Please cite this article as an Accepted Article; doi: 10.1111/j.1365-313X.2010.04363.x
Second generation bioethanol produced from lignocellulosic biomass is attracting attention as an ... more Second generation bioethanol produced from lignocellulosic biomass is attracting attention as an alternative energy source. In this study, a detailed knowledge of the composition and structure of common cattail (Typha latifolia L.) cell wall polysaccharides, obtained from stem or leaves, has been conducted using a wide set of techniques to evaluate this species as a potential bioethanol feedstock. Our results showed that common cattail cellulose content was high for plants in the order Poales and was accompanied by a small amount of cross-linked polysaccharides. A high degree of arabinose-substitution in xylans, a high syringyl/guaiacyl ratio in lignin and a low level of cell wall crystallinity could yield a good performance for lignocellulose saccharification. These results identify common cattail as a promising plant for use as potential bioethanol feedstock. To the best of our knowledge, this is the first in-depth analysis to be conducted of lignocellulosic material from common cattail.
Lignin is an essential polymer in vascular plants that plays key structural roles in vessels and ... more Lignin is an essential polymer in vascular plants that plays key structural roles in vessels and fibers. Lignification is induced by external inputs such as wounding, but the molecular mechanisms that link this stress to lignification remain largely unknown. In this work, we provide evidence that three maize (Zea mays) lignin repressors, MYB11, MYB31, and MYB42, participate in wound-induced lignification by interacting with ZML2, a protein belonging to the TIFY family. We determined that the three R2R3-MYB factors and ZML2 bind in vivo to AC-rich and GAT(A/C) cis-elements, respectively, present in a set of lignin genes. In particular, we show that MYB11 and ZML2 bind simultaneously to the AC-rich and GAT(A/C) cis-elements present in the promoter of the caffeic acid O-methyl transferase (comt) gene. We show that, like the R2R3-MYB factors, ZML2 also acts as a transcriptional repressor. We found that upon wounding and methyl jasmonate treatments, MYB11 and ZML2 proteins are degraded a...
A clone encoding a proline-rich protein (ZmPRP) has been obtained from maize root by differential... more A clone encoding a proline-rich protein (ZmPRP) has been obtained from maize root by differential screening of a maturing elongation root cDNA library. The amino acid sequence deduced from the full-length cDNA contains a putative signal peptide and a highly repetitive sequence containing the PEPK motif, indicating that the ZmPRP mRNA may code for a cell wall protein. The PEPK repeat is also found in a previously reported wheat sequence but differs from the repeated sequences found in hydroxyproline-rich glycoproteins (HRGP) and in dicot proline-rich proteins (PRP). In the maize genome, the ZmPRP protein is encoded by a single gene that is expressed in maturing regions of the root, in the hypocotyl and in the pericarp. In these organs, the ZmPRP mRNA accumulates in the xylem and surrounding cells, and in the epidermis. No ZmPRP mRNA was found in the phloem. The pattern of mRNA accumulation is very similar to the one observed for genes coding for proteins involved in lignin biosynthes...
Studies have revealed in plant chloroplasts, mitochondria, cell walls, and cytoplasm the existenc... more Studies have revealed in plant chloroplasts, mitochondria, cell walls, and cytoplasm the existence of transglutaminase (TGase) activities, similar to those known in animals and prokaryotes having mainly structural roles, but no protein has been associated to this type of activity in plants. A recent computational analysis has shown in Arabidopsis the presence of a gene, AtPng1p, which encodes a putative N-glycanase. AtPng1p contains the Cys-His-Asp triad present in the TGase catalytic domain. AtPng1p is a single gene expressed ubiquitously in the plant but at low levels in all light-assayed conditions. The recombinant AtPng1p protein could be immuno-detected using animal TGase antibodies. Furthermore, western-blot analysis using antibodies raised against the recombinant AtPng1p protein have lead to its detection in microsomal fraction. The purified protein links polyamines—spermine (Spm) > spermidine (Spd) > putrescine (Put)—and biotin-cadaverine to dimethylcasein in a calcium...
Chez plusieurs crucifères, deux activités se liant à l'ADNr, NF B et NF D, ont été identifiée... more Chez plusieurs crucifères, deux activités se liant à l'ADNr, NF B et NF D, ont été identifiées interagissant spécifiquement avec une séquence conservée du 5'ETS appelée A123BP. Nous avons caractérisés ces complexes et identifié leurs constituants majeurs. Ainsi, la protéine majeure impliquée dans le complexe constituant NF D correspond à une Nucléoline, tandis qu'une poly(ADP-ribose) polymerase semble être la protéine majeure du complexe correspondant à NF B. La Nucléoline est impliquée dans des nombreux évènements de la biogenèse du ribosome, y compris la régulation de la transcription des gènes ribosomiques. Par contre, aucune implication de la poly(ADP-ribose) polymérase dans la biogenèse du ribosome n'a été décrite jusqu'au présent dans la biogenèse du ribosome. Ainsi donc, nos résultats suggèrent un rôle de NF B et NF D dans la régulation des événements précoces de la biogenèse du ribosome chez les plantes crucifères.PERPIGNAN-BU Sciences (661362101) / Sudoc...
- Regulation of gene expression Number of black and white figures: 6 Number of colour figures: 2 ... more - Regulation of gene expression Number of black and white figures: 6 Number of colour figures: 2 Supplementary material: 2 colour figures and 2 tables
Chez plusieurs cruciferes, deux activites se liant a l'ADNr, NF B et NF D, ont ete identifiee... more Chez plusieurs cruciferes, deux activites se liant a l'ADNr, NF B et NF D, ont ete identifiees interagissant specifiquement avec une sequence conservee du 5'ETS appelee A123BP. Nous avons caracterises ces complexes et identifie leurs constituants majeurs. Ainsi, la proteine majeure impliquee dans le complexe constituant NF D correspond a une Nucleoline, tandis qu'une poly(ADP-ribose) polymerase semble etre la proteine majeure du complexe correspondant a NF B. La Nucleoline est impliquee dans des nombreux evenements de la biogenese du ribosome, y compris la regulation de la transcription des genes ribosomiques. Par contre, aucune implication de la poly(ADP-ribose) polymerase dans la biogenese du ribosome n'a ete decrite jusqu'au present dans la biogenese du ribosome. Ainsi donc, nos resultats suggerent un role de NF B et NF D dans la regulation des evenements precoces de la biogenese du ribosome chez les plantes cruciferes.
Caffeoyl Coenzyme A 3-O-Methyltransferase (CCoAOMT) and Caffeic acid-O-Methyltransferase (COMT) a... more Caffeoyl Coenzyme A 3-O-Methyltransferase (CCoAOMT) and Caffeic acid-O-Methyltransferase (COMT) are key enzymes in the biosynthesis of coniferyl and sinapyl alcohols, the precursors of guaiacyl (G) and syringyl (S) lignin subunits. The function of these enzymes was characterised in single and double mutant maize plants. In this work, we determined that the comt (brown-midrib 3) mutant plants display a reduction of the flavonolignin unit derived from tricin (a dimethylated flavone), demonstrating that COMT is a key enzyme involved in the synthesis of this compound. In contrast, the ccoaomt1 mutants displays wild type amount of tricin, suggesting that CCoAOMT1 is not essential for the synthesis of this compound. Based on our data, we suggest that CCoAOMT1 is involved in lignin biosynthesis at least in midribs. The phenotype of ccoaomt1 mutant plants displays no alterations, and their lignin content and composition remain unchanged. On the other hand, the ccoaomt1 comt mutant displays ...
Lodging is one of the causes of maize (Zea mays L.) production losses worldwide and, at least, th... more Lodging is one of the causes of maize (Zea mays L.) production losses worldwide and, at least, the resistance to stalk lodging has been positively correlated with stalk strength. In order to elucidate the putative relationship between cell wall, stalk strength and lodging resistance, twelve maize inbreds varying in rind penetration strength and lodging resistance were characterized for cell wall composition and structure. Stepwise multiple regression indicates that H lignin subunits confer a greater rind penetration strength. Besides, the predictive model for lodging showed that a high ferulic acid content increases the resistance to lodging, whereas those of diferulates decrease it. These outcomes highlight that the strength and lodging susceptibility of maize stems may be conditioned by structural features of cell wall rather than by the net amount of cellulose, hemicelluloses and lignin. The results presented here provide biotechnological targets in breeding programs aimed at imp...
This is an Accepted Article that has been peer-reviewed and approved for publication in the The P... more This is an Accepted Article that has been peer-reviewed and approved for publication in the The Plant Journal, but has yet to undergo copy-editing and proof correction. Please cite this article as an Accepted Article; doi: 10.1111/j.1365-313X.2010.04363.x
Second generation bioethanol produced from lignocellulosic biomass is attracting attention as an ... more Second generation bioethanol produced from lignocellulosic biomass is attracting attention as an alternative energy source. In this study, a detailed knowledge of the composition and structure of common cattail (Typha latifolia L.) cell wall polysaccharides, obtained from stem or leaves, has been conducted using a wide set of techniques to evaluate this species as a potential bioethanol feedstock. Our results showed that common cattail cellulose content was high for plants in the order Poales and was accompanied by a small amount of cross-linked polysaccharides. A high degree of arabinose-substitution in xylans, a high syringyl/guaiacyl ratio in lignin and a low level of cell wall crystallinity could yield a good performance for lignocellulose saccharification. These results identify common cattail as a promising plant for use as potential bioethanol feedstock. To the best of our knowledge, this is the first in-depth analysis to be conducted of lignocellulosic material from common cattail.
Lignin is an essential polymer in vascular plants that plays key structural roles in vessels and ... more Lignin is an essential polymer in vascular plants that plays key structural roles in vessels and fibers. Lignification is induced by external inputs such as wounding, but the molecular mechanisms that link this stress to lignification remain largely unknown. In this work, we provide evidence that three maize (Zea mays) lignin repressors, MYB11, MYB31, and MYB42, participate in wound-induced lignification by interacting with ZML2, a protein belonging to the TIFY family. We determined that the three R2R3-MYB factors and ZML2 bind in vivo to AC-rich and GAT(A/C) cis-elements, respectively, present in a set of lignin genes. In particular, we show that MYB11 and ZML2 bind simultaneously to the AC-rich and GAT(A/C) cis-elements present in the promoter of the caffeic acid O-methyl transferase (comt) gene. We show that, like the R2R3-MYB factors, ZML2 also acts as a transcriptional repressor. We found that upon wounding and methyl jasmonate treatments, MYB11 and ZML2 proteins are degraded a...
A clone encoding a proline-rich protein (ZmPRP) has been obtained from maize root by differential... more A clone encoding a proline-rich protein (ZmPRP) has been obtained from maize root by differential screening of a maturing elongation root cDNA library. The amino acid sequence deduced from the full-length cDNA contains a putative signal peptide and a highly repetitive sequence containing the PEPK motif, indicating that the ZmPRP mRNA may code for a cell wall protein. The PEPK repeat is also found in a previously reported wheat sequence but differs from the repeated sequences found in hydroxyproline-rich glycoproteins (HRGP) and in dicot proline-rich proteins (PRP). In the maize genome, the ZmPRP protein is encoded by a single gene that is expressed in maturing regions of the root, in the hypocotyl and in the pericarp. In these organs, the ZmPRP mRNA accumulates in the xylem and surrounding cells, and in the epidermis. No ZmPRP mRNA was found in the phloem. The pattern of mRNA accumulation is very similar to the one observed for genes coding for proteins involved in lignin biosynthes...
Studies have revealed in plant chloroplasts, mitochondria, cell walls, and cytoplasm the existenc... more Studies have revealed in plant chloroplasts, mitochondria, cell walls, and cytoplasm the existence of transglutaminase (TGase) activities, similar to those known in animals and prokaryotes having mainly structural roles, but no protein has been associated to this type of activity in plants. A recent computational analysis has shown in Arabidopsis the presence of a gene, AtPng1p, which encodes a putative N-glycanase. AtPng1p contains the Cys-His-Asp triad present in the TGase catalytic domain. AtPng1p is a single gene expressed ubiquitously in the plant but at low levels in all light-assayed conditions. The recombinant AtPng1p protein could be immuno-detected using animal TGase antibodies. Furthermore, western-blot analysis using antibodies raised against the recombinant AtPng1p protein have lead to its detection in microsomal fraction. The purified protein links polyamines—spermine (Spm) > spermidine (Spd) > putrescine (Put)—and biotin-cadaverine to dimethylcasein in a calcium...
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