293 results on '"Jouanin, Lise"'
Search Results
252. The role of glycine in determining the rate of glutathione synthesis in poplar. Possible implications for glutathione production during stress.
- Author
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Noctor, Graham, Arisi, Ana-Carolina M., Jouanin, Lise, Valadier, Marie-Hélène, Roux, Yvette, and Foyer, Christine H.
- Subjects
GLYCINE ,GLUTATHIONE ,ACETIC acid ,PLANT shoots ,CONDENSATION ,LEAVES - Abstract
The terminal step of glutathione (GSH) synthesis is the condensation of γ-glutamylcysteine (γ-EC) with glycine. Relatively little information exists concerning the importance of photorespiratory glycine in determining the rate of conversion of γ-EC to GSH. Consequently, the effect of exogenous glycine and of illumination on foliar contents of γ-EC and GSH was studied in excised leaves and leaf discs from untransformed poplar (Populus tremula x P. alba) and poplar overexpressing γ-glutamylcysteine synthetase (γ-ECS; EC 6.3.2.2). Poplars strongly overexpressing γ-ECS (ggs28) had enhanced levels of γ-EC and GSH compared to untransformed poplars. The relationship between γ-EC and GSH contents in ggs28 was light dependent. In illuminated leaves, GSH contents were up to 50-fold higher than γ-EC. On darkening, γ-EC accumulated markedly and GSH declined, so that the GSH: γ-EC ratio was close to 1. These dark-induced changes were prevented by supplying glycine through the petiole or by incubation of leaf discs on glycine. Dark accumulation of γ-EC in leaf discs from untransformed poplar was also prevented by supplying glycine. Supplying cysteine in the dark to discs from untransformed poplar and ggs28 increased γ-EC levels markedly but GSH levels only slightly. Subsequent illumination caused γ-EC to decrease and GSH to increase. Supplying glycine in concert with cysteine had similar effects to illumination. The data suggest that photorespiratory glycine is essential for GSH synthesis, especially under stress conditions, where increased amounts of GSH are required. [ABSTRACT FROM AUTHOR]
- Published
- 1997
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253. TL-DNA transformation decreases ABA level.
- Author
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Julliard, Jacques, Pelèse, Florence, Sotta, Bruno, Maldiney, Régis, Primard-Brisset, Catherine, Jouanin, Lise, Pelletier, Georges, and Miginiac, Emile
- Subjects
DNA ,NUCLEIC acids ,AGROBACTERIUM ,COLE crops ,TOBACCO ,HIGH performance liquid chromatography - Abstract
The endogenous levels of ABA were measured in Agrobacterium rhizogenes A
4 TL -DNA transformed oilseed rape (Brassica napus L. var. oleifera cv. Brutor and cv. Drakkar), cabbage (Brassica oleracea). A4 transformed tobacco (Nicotiana tabacum cv. Xanthi) and their normal counterparts, using high performance liquid chromatography and enzyme-linked immunosorbent assay. Measurements were made on different plant tissues (i.e. floral stem, terminal bud, young leaf, mature leaf, root and root tips) and ABA levels were compared in unstressed and osmotically stressed oilseed rape plants (cv. Brutor). In unstressed plants. in each of the 5 independent transformation events studied, a significant reduction (about 65% of control) in ABA concentration was observed in all transformed plants. When subjected to an osmotic stress, TL transformed Brutor plants showed a higher ABA accumulation than untransformed plants. The change in ABA content as a consequence of TL -DNA transformation is discussed with regard to phenotype, drought resistance and adaptability. [ABSTRACT FROM AUTHOR]- Published
- 1993
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254. Regulation of glutathione synthesis in leaves of transgenic poplar ( Populus tremula X P. alba) overexpressing glutathione synthetase.
- Author
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Strohm, Michael, Jouanin, Lise, Kunert, Karl Josef, Pruvost, Christophe, Polle, Andrea, Foyer, Christine Helen, and Rennenberg, Heinz
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- 1995
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255. Transformation of rapid cycling cabbage ( Brassica oleracea var. capitata) with Agrobacterium rhizogenes.
- Author
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Berthomieu, Pierre and Jouanin, Lise
- Abstract
Genetically transformed cabbage ( Brassica oleracea var. capitata) roots were obtained after inoculation with two engineered Agrobacterium rhizogenes strains, each harbouring a plant selectable marker gene in their T-DNA. Axenic root clones resistant to kanamycin or hygromycin B were established, most of which did not exhibit the phenotypic characteristics of Ri-transformed roots. Shoot regeneration was induced from roots after treatment with 2,4-dichlorophenoxyacetic acid (2,4-D). The resulting plants exhibited various phenotypes: some looked normal, while others showed the transformed phenotype observed in other species. Direct evidence for genetic transformation was obtained by molecular hybridization. The trait was transmitted to the progeny. Transformed cabbage plants can be obtained within 6 months using this approach. [ABSTRACT FROM AUTHOR]
- Published
- 1992
- Full Text
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256. Transgenic poplars: expression of chimeric genes using four different constructs.
- Author
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Leple, Jean, Brasileiro, Ana, Michel, Marie, Delmotte, Francis, and Jouanin, Lise
- Abstract
Leaf or stem explants of a hybrid poplar clone ( Populus tremula X Populus alba), sensitive to Agrobacterium tumefaciens, were co-cultivated either by an octopine or a nopaline disarmed A. tumefaciens modified strain. Transformed poplar shoots were readily regenerated from explants. The protocol was improved using the nopaline disarmed strain C58/pMP90 with the binary vector pBI121. This protocol was then used to test three other vectors. The first one, possessing a nptII gene fused to the CaMV 19S promoter, permitted regeneration of transformed shoots in presence of 50 to 100 mg/l kanamycin. The two other vectors carried an additional nptII gene under the control of the CaMV 35S or CaMV 35S promoter with a double enhancer sequence (CaMV 70). CaMV 70 promoter provided consistently higher level of gene expression than the other promoters in both callus and leaf tissues. [ABSTRACT FROM AUTHOR]
- Published
- 1992
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257. Unexpected effects of chitinases on the peach-potato aphid (Myzus persicae Sulzer) when delivered via transgenic potato plants (Solanum tuberosum Linné) and in vitro
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Saguez, Julien, Hainez, Romaric, Cherqui, Anas, Van Wuytswinkel, Olivier, Jeanpierre, Haude, Lebon, Gaël, Noiraud, Nathalie, Beaujean, Antony, Jouanin, Lise, Laberche, Jean-Claude, Vincent, Charles, and Giordanengo, Philippe
- Abstract
Abstract With the aim of producing insect-resistant potato plants, internode explants of Solanum tuberosum L. cv. Désirée were transformed with an Agrobacterium strain C58pMP90 containing an insect (Phaedon cochleariae: Coleoptera, Chrysomelidae) chitinase gene and the neomycin phosphotransferase (nptII) gene as selectable marker, both under the control of the viral CaMV 35S promoter. Three transformed potato lines (CH3, CH5 and CH25) exhibiting the highest chitinolytic activities were selected for feeding experiments with the peach-potato aphid, Myzus persicae (Sulzer), under controlled photoperiod and temperature conditions. Aphids fed on transgenic potato plants showed a reduced pre-reproductive period and an enhanced daily fecundity. Transgenic potato lines did not affect nymphal mortality, but improved several biological parameters related to aphid population’s growth. Artificial diets were used to provide active (1, 10, 100 and 500 µg ml-1) and inactive (500 µg ml-1) bacterial (Serratia marcescens) chitinase to M. persicae. These compounds increased nymph survival at all active chitinase doses when compared to the control diet, while inactive chitinase did not. Although the pre-reproductive period was slightly shortened and the daily fecundity slightly higher, active and inactive chitinase provided as food led a reduction from 1 to 1.5 day population’s doubling time. Therefore chitinase activity was responsible for the probiotic effects on aphids. Our results question the relevance of a chitinase-based strategy in the context of potato culture protection.
- Published
- 2005
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258. A new Arabidopsis thalianamutant deficient in the expression of O-methyltransferase impacts lignins and sinapoyl esters
- Author
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Goujon, Thomas, Sibout, Richard, Pollet, Brigitte, Maba, Bruno, Nussaume, Laurent, Bechtold, Nicole, Lu, Fachuang, Ralph, John, Mila, Isabelle, Barrière, Yves, Lapierre, Catherine, and Jouanin, Lise
- Abstract
A promoter-trap screen allowed us to identify an Arabidopsisline expressing GUS in the root vascular tissues. T-DNA border sequencing showed that the line was mutated in the caffeic acid O-methyltransferase 1 gene (AtOMT1) and therefore deficient in OMT1 activity. Atomt1is a knockout mutant and the expression profile of the AtOMT1 gene has been determined as well as the consequences of the mutation on lignins, on soluble phenolics, on cell wall digestibility, and on the expression of the genes involved in monolignol biosynthesis. In this mutant and relative to the wild type, lignins lack syringyl (S) units and contain more 5-hydroxyguaiacyl units (5-OH-G), the precursors of S-units. The sinapoyl ester pool is modified with a two-fold reduction of sinapoyl-malate in the leaves and stems of mature plants as well as in seedlings. In addition, LC-MS analysis of the soluble phenolics extracted from the seedlings reveals the occurrence of unusual derivatives assigned to 5-OH-feruloyl malate and to 5-OH-feruloyl glucose. Therefore, AtOMT1 enzymatic activity appears to be involved not only in lignin formation but also in the biosynthesis of sinapate esters. In addition, a deregulation of other monolignol biosynthetic gene expression can be observed in the Atomt1mutant. A poplar cDNA encoding a caffeic acid OMT (PtOMT1) was successfully used to complement the Atomt1mutant and restored both the level of S units and of sinapate esters to the control level. However, the over-expression of PtOMT1in wild-type Arabidopsisdid not increase the S-lignin content, suggesting that OMT is not a limiting enzyme for S-unit biosynthesis.
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- 2003
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259. Responses of antioxidative systems to acute ozone stress in transgenic poplar (Populus tremula × P. alba) over-expressing glutathione synthetase or glutathione reductase
- Author
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Strohm, Michael, Eiblmeier, Monika, Langebartels, Christian, Jouanin, Lise, Polle, Andrea, Sandermann, Heinrich, and Rennenberg, Heinz
- Abstract
Abstract. Wild-type hybrid poplar (Populus tremula × P. alba) plants and transgenic lines over-expressing glutathione reductase (GR) either in the cytosol (ca. 5-fold) or in the chloroplast (150- to 200-fold) or glutathione synthetase (GSS) in the cytosol (ca. 200-fold) were exposed for 3 days to ambient air or air containing 300 nl l-1 ozone for 7 h day-1. The contents and oxidation state of antioxidants (glutathione; ascorbate), the in vitro activities of target enzymes (GR, GSS), as well as the in vitro activities of ascorbate consuming (ascorbate peroxidase, APX) and regenerating (monodehydroascorbate reductase, MDAR; dehydroascorbate reductase, DHAR) enzymes were determined in the developing 2nd and the mature 5th leaves from the apex of the plants. The changes in the activities of the target enzymes GR and GSS also affected other components of the leaves' antioxidative system. Over-expression of GR in the chloroplast enhanced total glutathione contents of the leaves 2- to 3-fold. Foliar GSSG levels were enhanced in all transgenic poplar lines compared to wild-type plants. In developing leaves of transgenic plants, over-expressing GR in the cytosol or chloroplasts, APX and DHAR activities were higher, in mature leaves similar or lower than in wild-type plants. These differences between poplar lines did not mediate different sensitivities of the leaves to acute ozone exposure (Strohm et al., J Exp Bot 50:365-374). Still, components of the antioxidative system of the leaves showed both similar or specific reactions to acute ozone exposure in different poplar lines. Irrespective of leaf age total glutathione contents increased 2- to 3-fold in ozone-exposed leaves of all poplar lines. Also GSSG contents of the leaves increased, with the exception of plants over-expressing GR in the chloroplasts. Still a highly reduced state of glutathione was maintained in wild-type (>90%) and transgenic lines (ca. 80%) irrespective of ozone exposure. Apparently, GR activity was sufficient in all lines to compensate for ozone-mediated glutathione oxidation. Foliar GR activity increased up to 100% as a consequence of ozone treatment in wild-type and transgenic plants over-expressing GR in the cytosol, but not in plants over-expressing GR in the chloroplasts. The combined increase in total glutathione contents and GR activity in response to acute ozone exposure did not prevent injury and, therefore, cannot be considered a useful mechanism of defence, but rather an indicator of ozone-mediated oxidative stress. Total ascorbate contents and the activities of ascorbate consuming (APX) or regenerating enzymes (MDAR, DHAR) were not significantly affected by acute ozone exposure in all poplar lines. Ozone exposure strongly oxidised the foliar ascorbate pool except in leaves over-expressing GR in the chloroplast. Apparently, these leaves possess an enhanced capacity for ascorbate regeneration as a consequence of the strongly enhanced chloroplast GR activity and the simultaneously increased APX activity and glutathione levels. The enhanced antioxidative capacity did not prevent ozone-mediated injury to the leaves, most likely due to different sites of primary ozone reactions. Despite higher total ascorbate contents and higher APX activities in developing than in mature leaves, these and other components of the antioxidative system analysed in this study were not responsible for the higher sensitivity to acute ozone exposure of mature compared to developing poplar leaves.
- Published
- 2002
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260. Isolation and identification of TL‐DNA/plant junctions in Convolvulus arvensistransformed by Agrobacterium rhizogenesstrain A4
- Author
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Slightom, Jerry L., Jouanin, Lise, Leach, Francesca, Drong, Roger F., and Tepfer, David
- Abstract
We have constructed a Charon 4A phage library containing insert DNA isolated from a morning glory (Convolvulus arvensis) plant (clone 7) regenerated from a root organ culture incited by Agrobacterium rhizogenes, strain A4. Using a subcloned region of the Ri plasmid as 32P‐labeled probe, two lambda clones containing most of the ‘left’ T‐DNA (TL) region were isolated. One of these lambda clones contains the left TL‐DNA/plant junction, which was located by comparing nucleotide sequences from the appropriate regions of the Ri plasmid and this lambda clone. A 25‐bp sequence found near this left TL‐DNA/plant junction matches the 25‐bp terminal sequence found at or near T‐DNA/plant junctions of both nopaline‐ and octopine‐type A. tumefaciensTi plasmids. A possible location for the right Ri TL‐DNA/plant junction in C. arvensisclone 7 was found by obtaining the nucleotide sequence surrounding its mapped location. Hybridization of plant DNA found adjacent to the left TL‐DNA/plant junction against total C. arvensisDNA shows that this T‐DNA integration occurred in a plant DNA region that does not contain highly repetitive DNA sequences. Nucleotide sequence analysis of 1004 bp of this plant DNA revealed no complete or partial open reading frames, but this plant DNA does have the potential to form various secondary structures which might play a role in the T‐DNA integration event.
- Published
- 1985
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261. An alternative approach for gene transfer in trees using wild-typeAgrobacterium strains
- Author
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Brasileiro, Ana Cristina Miranda, Leplé, Jean-Charles, Muzzin, Joris, Ounnoughi, Dalila, Michel, Marie-France, and Jouanin, Lise
- Abstract
Micropropagated shoots of three forest tree species, poplar (Populus tremula × P.alba), wild cherry (Prunus avium L.) and walnut (Juglans nigra × J. regia), were inoculated each with six different wild-typeAgrobacterium strains. Poplar and wild cherry developed tumors that grew hormone-independently, whereas on walnut, gall formation was weak. On poplar and wild cherry, tumors induced by nopaline strains developed spontaneously shoots that had a normal phenotype and did not carry oncogenic T-DNA. From these observations, we have established a co-inoculation method to transform plants, using poplar as an experimental model. The method is based on inoculation of stem internodes with anAgrobacterium suspension containing both an oncogenic strain that induces shoot differentiation and a disarmed strain that provides the suitable genes in a binary vector. We used the vector pBI121 carryingneo (kanamycin resistance) anduidA (ß-glucuronidase) genes to facilitate early selection and screening. Poplar plants derived from kanamycin-resistant shoots that did not carry oncogenic T-DNA, were shown to contain and to expressneo anduidA genes. These results suggest that wild-typeAgrobacterium strains that induce shoot formation directly from tumors can be used as a general tool for gene transfer, avoiding difficult regeneration procedures.
- Published
- 1991
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262. RFLP of RT-PCR products: Application to the expression ofCHS multigene family in poplar
- Author
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Lurin, Claire and Jouanin, Lise
- Abstract
A novel method for studying differential expression of multigene family members based on the high sensitivity of RT-PCR completed by restriction site polymorphism of DNA is described. This method allows the identification of specific patterns of expression of fourchalcone synthase genes in a Hunnegem poplar clone (Populus trichocarpa ×Populus deltoides).
- Published
- 1995
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263. Toxicity toChrysomela tremulae (Coleoptera: Chrysomelidae) of transgenic poplars expressing a cysteine proteinase inhibitor
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Leplé, Jean Charles, Bonadé-Bottino, Michel, Augustin, Sylvie, Pilate, Gilles, Lê Tân, Véronique Dumanois, Delplanque, André, Cornu, Daniel, and Jouanin, Lise
- Abstract
The aim of this study was to test the potential of proteinase inhibitors to controlChrysomela tremulae, a beetle that causes severe damage in young plantations and in short-rotation intensive culture (SRIC) of poplar. As a first step, cysteine proteinases were determined to be the major digestive proteinases ofC. tremulae and oryzacystatin OCI, a cysteine proteinase inhibitor, was shown to inhibit this activityin vitro. The gene encoding OCI was introduced into poplar (Populus tremula ×P. tremuloides) and transgenic plants expressing OCI at a high level were selected. Feeding tests on these transgenic plants demonstrate the toxicity of OCI-producing poplar leaves againstC. tremulae larvae.
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- 1995
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264. Potential use of theaux2 gene fromAgrobacterium rhizogenes as a conditional negative marker in transgenic cabbage
- Author
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Béclin, Christophe, Charlot, Florence, Botton, Emmanuel, Jouanin, Lise, and Dore, Claire
- Abstract
An originalAgrobacterium tumefaciens-mediated transformation procedure, based on the actions of both wild type and disarmed bacterial strains, was developed. Theaux2 gene ofA. rhizogenes was introduced into a rapid-cycling genotype of cabbage (Brassica oleracea L.). Theaux2 gene product converts naphthalene acetamide into the auxin naphthalene acetic acid. Expression of this gene in the transgenic progeny grownin vitro led to an altered root phenotype. On a medium supplemented with napthalene acetamide (NAM), two of the three analysed progenies were characterized by the formation of callus instead of roots, whereas on a NAM-free medium all the plantlets from these progenies presented a normal phenotype. Expression of theaux2 gene was also assessed under horticultural conditions by sowing seeds in sand and watering them with a nutritive solution supplemented with NAM. Under these conditions, NAM inhibited the formation of a root system in transgenic plantlets and induced the death of the transgenic plantlets three to four weeks after germination. Thus,aux2 acts as a lethal conditional marker which could be used in negative selection of cabbage. Potential utilization of theaux2 gene to screen spontaneous androgenetic plants in order to transfer cytoplasmic male sterility in a single generation is discussed.
- Published
- 1993
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265. Expression of the mutantArabidopsis thaliana acetolactate synthase gene confers chlorsulfuron resistance to transgenic poplar plants
- Author
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Brasileiro, Ana, Tourneur, Colette, Leple, Jean-Charles, Combes, Valérie, and Jouanin, Lise
- Abstract
Abstract: The mutant acetolactate synthase (crs1-1) gene fromArabidopsis thaliana, which confers resistance to the herbicide chlorsulfuron, was transferred to a hybrid poplar (Populus tremulaP. alba) using twoAgrobacterium-mediated transformation methods (co-inoculation and co-cultivation). Two different constructs were used. In one, the mutantcrs1-1 gene was placed under the control of its own promoter, and, in the other, this gene was under the control of the duplicated cauliflower mosaic virus 35S promoter (70 promoter). The transformation efficiency ranged from 22 to 32% of the tumours in co-inoculation and from 67 to 77% of the stem explants in co-cultivation experiments. The usefulness of the herbicide chlorsulfuron as a selectable marker gene was also demonstrated. Successful genetic transformation was verified by Southern and northern analyses and enzyme activity. Plants carrying thecrs1-1 mutant gene under the control of the 70 promoter showed high levels of transcription and activity whereas plants carrying the nativecrs1-1 gene showed low levels of expression. However, transgenic plants expressing each of the chimaericcrs1-1 genes are completely resistant to high doses of chlorsulfuron in greenhouse tests.
- Published
- 1992
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266. Genetic transformation of oilseed rape (Brassica napu) by Ri T-DNA of Agrobacterium rhizogenes strain A4 and analysis of inheritance of the transformed phenotype
- Author
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Guerche, Philippe, Jouanin, Lise, Tepfer, David, Pelletier, G., Unité de recherche Génétique et amélioration des plantes (GAP), Institut National de la Recherche Agronomique (INRA), Laboratoire de biologie de la rhizosphère, Laboratoire de biologie cellulaire et moléculaire, and ProdInra, Migration
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[SDV] Life Sciences [q-bio] ,[SDV]Life Sciences [q-bio] ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 1987
267. Direct gene transfer in Brassica napus
- Author
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Guerche, Philippe, Charbonnier, M., Jouanin, Lise, Pelletier, G., Unité de Recherche en Génétique et Amélioration des Plantes (UR254), Institut National de la Recherche Agronomique (INRA), Chercheur indépendant, and ProdInra, Archive Ouverte
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[SDV] Life Sciences [q-bio] ,[SDV]Life Sciences [q-bio] ,Brassica napus ,Direct gene transfer - Abstract
Direct gene transfer in Brassica napus. International Symposium Plant Molecular Biology CNRS/INRA
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- 1986
268. Nucleotide sequence analysis of the TL-DNA of an Agrobacterium rhizogenes agropine type plasmid: identification of open-reading frames
- Author
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Slightom, J., Durand Tardif, Marie-Hélène, Jouanin, Lise, Tepfer, David, ProdInra, Migration, Laboratoire de biologie cellulaire et moléculaire, Institut National de la Recherche Agronomique (INRA), and Laboratoire de biologie de la rhizosphère
- Subjects
[SDV] Life Sciences [q-bio] ,[SDV]Life Sciences [q-bio] ,BIOLOGIE MOLECULAIRE ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 1986
269. Transformation of rapeseed (Brassica napus ) and Nicotiana plumbaginifolia by Agrobacterium rhizogenes A4 : regeneration of transformed plants and structure of the T-DNA
- Author
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Guerche, Philippe, Tourneur, J., Tourneur, C., Tepfer, David, Jouanin, Lise, Unité de Recherche en Génétique et Amélioration des Plantes (UR254), Institut National de la Recherche Agronomique (INRA), Chercheur indépendant, and ProdInra, Archive Ouverte
- Subjects
[SDV] Life Sciences [q-bio] ,[SDV]Life Sciences [q-bio] ,fungi ,T-DNA ,Brassica napus ,food and beverages ,Nicotiana plumbaginifolia ,biochemical phenomena, metabolism, and nutrition ,Agrobacterium rhizogenes A4 - Abstract
Transformation of rapeseed (Brassica napus ) and Nicotiana plumbaginifolia by Agrobacterium rhizogenes A4 : regeneration of transformed plants and structure of the T-DNA. 17. Lunteren Lectures on Molecular Genetics
- Published
- 1985
270. Expression vectors based on the Agrobacterium rhizogenes Ri transformation system
- Author
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Robaglia, Christophe, Vilaine, Francoise, Pautot, Veronique, Raimond, F., Amselem, Joëlle, Jouanin, Lise, Casse-Delbart, F., Tepfer, Mark, Laboratoire de biologie cellulaire et moléculaire, and Institut National de la Recherche Agronomique (INRA)
- Subjects
BACTERIOLOGIE ,[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 1987
271. Localization of the region of the pRi TL-DNA responsible for the A.rhizogenes transformed phenotype
- Author
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Jouanin, Lise, Vilaine, Francoise, Tourneur, J., Pautot, Veronique, TOURNEUR, Colette, Muller, J.F., Caboche, Michel, Casse-Delbart, F., Laboratoire de biologie cellulaire et moléculaire, and Institut National de la Recherche Agronomique (INRA)
- Subjects
BACTERIOLOGIE ,[SDV]Life Sciences [q-bio] ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 1987
272. Transfer into tobacco of a 4,3 Kb fragment of the TL-DNA of A. rhizogenes
- Author
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JOUANIN, Lise, Vilaine, Francoise, Tourneur, J., Pautot, Veronique, TOURNEUR, Colette, Muller, J.F., Caboche, Michel, Casse-Delbart, F., UR : Laboratoire de Biologie Cellulaire, Versailles, Laboratoire de Biologie Cellulaire, Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Laboratoire de biologie cellulaire et moléculaire, and Institut National de la Recherche Agronomique (INRA)
- Subjects
[SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding ,[SDV]Life Sciences [q-bio] ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 1987
273. Plasmide Ri et transfert genetique dans les plantes
- Author
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Casse-Delbart, F., Birot, A.M., Bouchez, David, Jouanin, Lise, Pautot, Veronique, Robaglia, Christophe, Tepfer, Mark, Tourneur, J., Vilaine, Francoise, Laboratoire de biologie cellulaire et moléculaire, and Institut National de la Recherche Agronomique (INRA)
- Subjects
[SDV]Life Sciences [q-bio] ,BIOLOGIE MOLECULAIRE ,ComputingMilieux_MISCELLANEOUS - Abstract
National audience
- Published
- 1986
274. Studies and uses of the Ri plasmids of Agrobacterium rhizogenes
- Author
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Birot, A.M., Bouchez, David, Casse-Delbart, M., Durand Tardif, Marie-Hélène, Jouanin, Lise, Pautot, Veronique, Robaglia, Christophe, Tepfer, David, Tepfer, Mark, Tourneur, J., Vilaine, Francoise, Laboratoire de biologie cellulaire et moléculaire, Institut National de la Recherche Agronomique (INRA), Laboratoire de biologie de la rhizosphère, and ProdInra, Migration
- Subjects
[SDV] Life Sciences [q-bio] ,[SDV]Life Sciences [q-bio] ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 1987
275. Transfer of a 4.3-kb fragment of the TL-DNA of Agrobacterium rhizogenes strain A4 confers the pRi transformed phenotype to regenerated tobacco plants
- Author
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Jouanin, Lise, primary, Vilaine, Françoise, additional, Tourneur, Jacques, additional, Tourneur, Colette, additional, Pautot, Véronique, additional, Muller, Jean François, additional, and Caboche, Michel, additional
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- 1987
- Full Text
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276. Isolation and identification of TL-DNA/plant junctions in Convolvulus arvensis transformed by Agrobacterium rhizogenes strain A4
- Author
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Slightom, Jerry L., primary, Jouanin, Lise, additional, Leach, Francesca, additional, Drong, Roger F., additional, and Tepfer, David, additional
- Published
- 1985
- Full Text
- View/download PDF
277. Environmental impact assessment and monitoring of genetically modified trees.
- Author
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Gallardo, Fernando, Ionita, Lucia, Ruohonen-Lehto, Marja, Harfouche, Antoine, Biricolti, Stefano, Boerjan, Wout, Glandorf, Boet, Jouanin, Lise, Fladung, Matthias, and Vettori, Cristina
- Subjects
ENVIRONMENTAL impact analysis - Abstract
An abstract of the conference paper "Environmental impact assessment and monitoring of genetically modified trees," by Fernando Gallardo and colleagues is presented.
- Published
- 2011
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- View/download PDF
278. AtBXL1 , a novel higher plant (Arabidopsis thaliana ) putative beta-xylosidase gene, is involved in secondary cell wall metabolism and plant development.
- Author
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Goujon, Thomas, Minic, Zoran, El Amrani, Abdelhak, Lerouxel, Olivier, Aletti, Estelle, Lapierre, Catherine, Joseleau, Jean-Paul, and Jouanin, Lise
- Subjects
PLANT cell walls ,ARABIDOPSIS ,PLANT genetics ,BETA-glucuronidase genes - Abstract
Summary To investigate mechanisms involved in cell wall development, an Arabidopsis T-DNA insertion mutant collection was screened to identify mutants with beta-glucuronidase fusion gene expression in tissues undergoing secondary cell wall thickening. This promoter-trapping strategy allowed the isolation of a transformant containing the GUS coding sequence inserted 700 bp upstream of the ATG of a putative beta-xylosidase gene. The transformant has no phenotype as the expression of the gene was not disrupted by the insertion. The analysis of the predicted protein, AtBXL1, suggests its targeting to the extracellular matrix and its involvement in cell wall metabolism through a putative activity towards xylans. The 2-kb promoter sequence of AtBXL1 was fused to the GUS coding sequence and introduced into wild-type Arabidopsis thaliana . GUS expression was shown to be restricted to tissues undergoing secondary cell wall formation. Beta-xylosidase activity was associated with the cell wall-enriched fraction of different organs of wild-type plants. The level of activity correlates with transcript accumulation of AtBXL1 and other AtBXL1 -related genes. Transgenic plants expressing the AtBXL1 cDNA in antisense orientation were generated. Lines exhibiting the highest decrease in AtBXL1 transcript accumulation and beta-xylosidase activity had phenotypic alterations. This newly identified gene is proposed to be involved in secondary cell wall hemicellulose metabolism and plant development. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
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279. Arabidopsis peroxidase-catalyzed copolymerization of coniferyl and sinapyl alcohols: Kinetics of an endwise process
- Author
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Demont-Caulet, Nathalie, Lapierre, Catherine, Jouanin, Lise, Baumberger, Stéphanie, and Méchin, Valérie
- Subjects
- *
ARABIDOPSIS thaliana , *PEROXIDASE , *POLYMERIZATION , *ALCOHOLS (Chemical class) , *CHEMICAL kinetics , *LIGNINS , *LIQUID chromatography , *CHEMICAL structure - Abstract
Abstract: In order to determine the mechanism of the earlier copolymerization steps of two main lignin precursors, sinapyl (S) alcohol and coniferyl (G) alcohol, microscale in vitro oxidations were carried out with a PRX34 Arabidopsis thaliana peroxidase in the presence of H2O2. This plant peroxidase was found to have an in vitro polymerization activity similar to the commonly used horseradish peroxidase. The selected polymerization conditions lead to a bulk polymerization mechanism when G alcohol was the only phenolic substrate available. In the same conditions, the presence of S alcohol at a 50/50 S/G molar ratio turned this bulk mechanism into an endwise one. A kinetics monitoring (size-exclusion chromatography and liquid chromatography–mass spectrometry) of the different species formed during the first 24h oxidation of the S/G mixture allowed sequencing the bondings responsible for oligomerization. Whereas G homodimers and GS heterodimers exhibit low reactivity, the SS pinoresinol structure act as a nucleating site of the polymerization through an endwise process. This study is particularly relevant to understand the impact of S units on lignin structure in plants and to identify the key step at which this structure is programmed. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
280. A TILLING Platform for Functional Genomics in Brachypodium distachyon.
- Author
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Dalmais, Marion, Antelme, Sébastien, Ho-Yue-Kuang, Séverine, Wang, Yin, Darracq, Olivier, d’Yvoire, Madeleine Bouvier, Cézard, Laurent, Légée, Frédéric, Blondet, Eddy, Oria, Nicolas, Troadec, Christelle, Brunaud, Véronique, Jouanin, Lise, Höfte, Herman, Bendahmane, Abdelafid, Lapierre, Catherine, and Sibout, Richard
- Subjects
- *
BRACHYPODIUM , *FUNCTIONAL genomics , *PLANT phylogeny , *PLANT enzymes , *TRANSFERASES , *GENETIC mutation , *PLANT genomes - Abstract
The new model plant for temperate grasses, Brachypodium distachyon offers great potential as a tool for functional genomics. We have established a sodium azide-induced mutant collection and a TILLING platform, called “BRACHYTIL”, for the inbred line Bd21-3. The TILLING collection consists of DNA isolated from 5530 different families. Phenotypes were reported and organized in a phenotypic tree that is freely available online. The tilling platform was validated by the isolation of mutants for seven genes belonging to multigene families of the lignin biosynthesis pathway. In particular, a large allelic series for BdCOMT6, a caffeic acid O-methyl transferase was identified. Some mutants show lower lignin content when compared to wild-type plants as well as a typical decrease of syringyl units, a hallmark of COMT-deficient plants. The mutation rate was estimated at one mutation per 396 kb, or an average of 680 mutations per line. The collection was also used to assess the Genetically Effective Cell Number that was shown to be at least equal to 4 cells in Brachypodium distachyon. The mutant population and the TILLING platform should greatly facilitate functional genomics approaches in this model organism. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
281. Impact of the Absence of Stem-Specific β-Glucosidases on Lignin and Monolignols.
- Author
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Chapelle, Aurélie, Morreel, Kris, Vanholme, Ruben, Le-Bris, Philippe, Morin, Halima, Lapierre, Catherine, Boerjan, Wout, Jouanin, Lise, and Demont-Caulet, Nathalie
- Subjects
- *
BIOSYNTHESIS , *BETA-glucosidase , *ARABIDOPSIS thaliana , *MASS spectrometry , *HIGH performance liquid chromatography , *LIGNINS - Abstract
Monolignol glucosides are thought to be implicated in the lignin biosynthesis pathway as storage and/or transportation forms of cinnamyl alcohols between the cytosol and the lignifying cell walls. The hydrolysis of these monolignol glucosides would involve β-glucosidase activities. In Arabidopsis (Arabidopsis thaliana), in vitro studies have shown the affinity of β-GLUCOSIDASE45 (BGLU45) and BGLU46 for monolignol glucosides. BGLU45 and BGLU46 genes are expressed in stems. Immunolocalization experiments showed that BGLU45 and BGLU46 proteins are mainly located in the interfascicular fibers and in the protoxylem, respectively. Knockout mutants for BGLU45 or BGLU46 do not have a lignin-deficient phenotype. Coniferin and syringin could be detected by ultra-performance liquid chromatography-mass spectrometry in Arabidopsis stems. Stems from BGLU45 and BGLU46 mutant lines displayed a significant increase in coniferin content without any change in coniferyl alcohol, whereas no change in syringin content was observed. Other glucosylated compounds of the phenylpropanoid pathway were also deregulated in these mutants, but to a lower extent. By contrast, BGLU47, which is closely related to BGLU45 and BGLU46, is not implicated in either the general phenylpropanoid pathway or in the lignification of stems and roots. These results confirm that the major in vivo substrate of BGLU45 and BGLU46 is coniferin and suggest that monolignol glucosides are the storage form of monolignols in Arabidopsis, but not the direct precursors of lignin. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
282. Disruption of LACCASE4 and 17 Results in Tissue-Specific Alterations to Lignification of Arabidopsis thaliana Stems.
- Author
-
Berthet, Serge, Demont-Caulet, Nathalie, Pollet, Brigitte, Bidzinski, Przemyslaw, Cézard, Laurent, Bris, Phillipe Le, Borrega, Nero, Hervé, Jonathan, Blondet, Eddy, Balzergue, Sandrine, Lapierre, Catherine, and Jouanin, Lise
- Subjects
- *
LIGNIFICATION , *LACCASE , *LIGNINS , *PEROXIDASE - Abstract
Peroxidases have been shown to be involved in the polymerization of lignin precursors, but it remains unclear whether laccases (EC 1.10.3.2) participate in constitutive lignification. We addressed this issue by studying laccase T-DNA insertion mutants in Arabidopsis thaliana. We identified two genes, LAC4 and LAC17 , which are strongly expressed in stems. LAC17 was mainly expressed in the interfascicular fibers, whereas LAC4 was expressed in vascular bundles and interfascicular fibers. We produced two double mutants by crossing the LAC17 (lac17) mutant with two LAC4 mutants (lac4-1 and lac4-2). The single and double mutants grew normally in greenhouse conditions. The single mutants had moderately low lignin levels, whereas the stems of lac4-1 lac17 and lac4-2 lac17 mutants had lignin contents that were 20 and 40% lower than those of the control, respectively. These lower lignin levels resulted in higher saccharification yields. Thioacidolysis revealed that disrupting LAC17 principally affected the deposition of G lignin units in the interfascicular fibers and that complementation of lac17 with LAC17 restored a normal lignin profile. This study provides evidence that both LAC4 and LAC17 contribute to the constitutive lignification of Arabidopsis stems and that LAC17 is involved in the deposition of G lignin units in fibers. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
283. The Simultaneous Repression of CCR and CAD, Two Enzymes of the Lignin Biosynthetic Pathway, Results in Sterility and Dwarfism in Arabidopsis thaliana.
- Author
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Thévenin, Johanne, Pollet, Brigitte, Letarnec, Bruno, Saulnier, Luc, Gissot, Lionel, Maia-Grondard, Alessandra, Lapierre, Catherine, and Jouanin, Lise
- Subjects
- *
ARABIDOPSIS thaliana , *LIGNINS , *DWARFISM , *STERILITY in plants , *AUXIN , *PLANT cell walls , *PLANTS - Abstract
Cinnamoyl CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the last steps of monolignol biosynthesis. In Arabidopsis, one CCR gene (CCR1, At1g15950) and two CAD genes (CAD C At3g19450 and CAD D At4g34230) are involved in this pathway. A triple cad c cad d ccr1 mutant, named ccc, was obtained. This mutant displays a severe dwarf phenotype and male sterility. The lignin content in ccc mature stems is reduced to 50% of the wild-type level. In addition, stem lignin structure is severely affected, as shown by the dramatic enrichment in resistant inter-unit bonds and incorporation into the polymer of monolignol precursors such as coniferaldehyde, sinapaldehyde, and ferulic acid. Male sterility is due to the lack of lignification in the anther endothecium, which causes the failure of anther dehiscence and of pollen release. The ccc hypolignified stems accumulate higher amounts of flavonol glycosides, sinapoyl malate and feruloyl malate, which suggests a redirection of the phenolic pathway. Therefore, the absence of CAD and CCR, key enzymes of the monolignol pathway, has more severe consequences on the phenotype than the individual absence of each of them. Induction of another CCR (CCR2, At1g80820) and another CAD (CAD1, At4g39330) does not compensate the absence of the main CCR and CAD activities. This lack of CCR and CAD activities not only impacts lignification, but also severely affects the development of the plants. These consequences must be carefully considered when trying to reduce the lignin content of plants in order to facilitate the lignocellulose-to-bioethanol conversion process. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
- Full Text
- View/download PDF
284. Cinnamyl alcohol dehydrogenases-C and D, key enzymes in lignin biosynthesis, play an essential role in disease resistance in Arabidopsis.
- Author
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TRONCHET, MAURICE, BALAGUÉ, CLAUDINE, KROJ, THOMAS, JOUANIN, LISE, and ROBY, DOMINIQUE
- Subjects
- *
PLANT diseases , *ARABIDOPSIS , *CROP losses , *PLANT ecology , *GARDEN pests - Abstract
The deposition of lignin during plant–pathogen interactions is thought to play a role in plant defence. However, the function of lignification genes in plant disease resistance is poorly understood. In this article, we provide genetic evidence that the primary genes involved in lignin biosynthesis in Arabidopsis, CAD-C and CAD-D, act as essential components of defence to virulent and avirulent strains of the bacterial pathogen Pseudomonas syringae pv. tomato, possibly through the salicylic acid defence pathway. Thus, in contrast with cellulose synthesis, whose alteration leads to an increase in disease resistance, alteration of the cell wall lignin content leads directly or indirectly to defects in some defence components. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
285. A TILLING Platform for Functional Genomics in Brachypodium distachyon.
- Author
-
Dalmais M, Antelme S, Ho-Yue-Kuang S, Wang Y, Darracq O, d'Yvoire MB, Cézard L, Légée F, Blondet E, Oria N, Troadec C, Brunaud V, Jouanin L, Höfte H, Bendahmane A, Lapierre C, and Sibout R
- Subjects
- Biosynthetic Pathways, Brachypodium genetics, Brachypodium metabolism, Genome, Plant, Lignin metabolism, Models, Molecular, Phenotype, Phylogeny, Plant Breeding, Plant Proteins chemistry, Sequence Analysis, DNA, Brachypodium growth & development, Genomics methods, Mutation, Plant Proteins genetics
- Abstract
The new model plant for temperate grasses, Brachypodium distachyon offers great potential as a tool for functional genomics. We have established a sodium azide-induced mutant collection and a TILLING platform, called "BRACHYTIL", for the inbred line Bd21-3. The TILLING collection consists of DNA isolated from 5530 different families. Phenotypes were reported and organized in a phenotypic tree that is freely available online. The tilling platform was validated by the isolation of mutants for seven genes belonging to multigene families of the lignin biosynthesis pathway. In particular, a large allelic series for BdCOMT6, a caffeic acid O-methyl transferase was identified. Some mutants show lower lignin content when compared to wild-type plants as well as a typical decrease of syringyl units, a hallmark of COMT-deficient plants. The mutation rate was estimated at one mutation per 396 kb, or an average of 680 mutations per line. The collection was also used to assess the Genetically Effective Cell Number that was shown to be at least equal to 4 cells in Brachypodium distachyon. The mutant population and the TILLING platform should greatly facilitate functional genomics approaches in this model organism.
- Published
- 2013
- Full Text
- View/download PDF
286. Sequencing around 5-hydroxyconiferyl alcohol-derived units in caffeic acid O-methyltransferase-deficient poplar lignins.
- Author
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Lu F, Marita JM, Lapierre C, Jouanin L, Morreel K, Boerjan W, and Ralph J
- Subjects
- Cell Wall chemistry, Molecular Structure, Lignin chemistry, Methyltransferases chemistry, Phenols chemistry, Populus chemistry
- Abstract
Caffeic acid O-methyltransferase (COMT) is a bifunctional enzyme that methylates the 5- and 3-hydroxyl positions on the aromatic ring of monolignol precursors, with a preference for 5-hydroxyconiferaldehyde, on the way to producing sinapyl alcohol. Lignins in COMT-deficient plants contain benzodioxane substructures due to the incorporation of 5-hydroxyconiferyl alcohol (5-OH-CA), as a monomer, into the lignin polymer. The derivatization followed by reductive cleavage method can be used to detect and determine benzodioxane structures because of their total survival under this degradation method. Moreover, partial sequencing information for 5-OH-CA incorporation into lignin can be derived from detection or isolation and structural analysis of the resulting benzodioxane products. Results from a modified derivatization followed by reductive cleavage analysis of COMT-deficient lignins provide evidence that 5-OH-CA cross couples (at its beta-position) with syringyl and guaiacyl units (at their O-4-positions) in the growing lignin polymer and then either coniferyl or sinapyl alcohol, or another 5-hydroxyconiferyl monomer, adds to the resulting 5-hydroxyguaiacyl terminus, producing the benzodioxane. This new terminus may also become etherified by coupling with further monolignols, incorporating the 5-OH-CA integrally into the lignin structure.
- Published
- 2010
- Full Text
- View/download PDF
287. Characterisation of adult green lacewing (Chrysoperla carnea) digestive physiology: impact of a cysteine protease inhibitor and a synthetic pyrethroid.
- Author
-
Mulligan EA, Ferry N, Jouanin L, Romeis J, and Gatehouse AM
- Subjects
- Animals, Cysteine Proteinase Inhibitors analysis, Cysteine Proteinase Inhibitors biosynthesis, Cysteine Proteinase Inhibitors isolation & purification, Digestion physiology, Female, Gastrointestinal Tract drug effects, Gastrointestinal Tract enzymology, Gastrointestinal Tract physiology, Insecta chemistry, Insecta enzymology, Male, Plants, Genetically Modified, Pollen genetics, Pyrethrins chemical synthesis, Recombinant Proteins analysis, Recombinant Proteins biosynthesis, Recombinant Proteins isolation & purification, Recombinant Proteins toxicity, Cysteine Proteinase Inhibitors toxicity, Digestion drug effects, Insecta drug effects, Insecta physiology, Pyrethrins toxicity
- Abstract
Background: In spite of concern regarding potential non-target effects of GM crops, few studies have compared GM pest control with conventional methods. The impacts of cypermethrin and oilseed rape expressing oryzacystatin-1 (OC-1) were compared in this study on the predator Chrysoperla carnea (Stephens)., Results: Adults fed purified rOC-1 showed a subtle shift in digestive protease profile, with an increasing reliance on serine proteases (chymotrypsin), increase in aspartic proteases and a slight reduction in elastase activity. Although there were no effects on mortality, onset of oviposition was delayed; however, once egg production commenced, egg laying and hatching success rates were comparable with those of controls. Oryzacystatin-1 expressed in pollen showed no detrimental effects. Cypermethrin had no effect on mortality owing to high levels of non-specific esterase activity resulting in partial breakdown of the insecticide. In spite of this, there was a significant delay in onset of oviposition and a significant reduction in egg production and viability., Conclusion: This study demonstrates the potential for pest management to impact on predators, but importantly it highlights the ability of the predator to detoxify/respond to treatments with different modes of action. In this case, exposure to an insecticide carried a greater fitness cost than exposure to a protease inhibitor expressed in transgenic crops.
- Published
- 2010
- Full Text
- View/download PDF
288. Purification, cloning and functional characterization of an endogenous beta-glucuronidase in Arabidopsis thaliana.
- Author
-
Eudes A, Mouille G, Thévenin J, Goyallon A, Minic Z, and Jouanin L
- Subjects
- Amino Acid Sequence, Arabidopsis growth & development, Arabidopsis Proteins genetics, Chromatography, Cloning, Molecular, Genes, Plant, Glucuronic Acid metabolism, Glucuronidase genetics, Glucuronidase isolation & purification, Hydrogen-Ion Concentration, Hypocotyl growth & development, Molecular Sequence Data, Mucoproteins isolation & purification, Mucoproteins metabolism, Plant Proteins isolation & purification, Plant Proteins metabolism, Plant Roots growth & development, Plants, Genetically Modified enzymology, Plants, Genetically Modified genetics, Polysaccharides metabolism, RNA, Plant genetics, Temperature, Transformation, Genetic, Arabidopsis enzymology, Arabidopsis genetics, Arabidopsis Proteins metabolism, Glucuronidase metabolism
- Abstract
Beta-glucuronidase (GUS) activities have been extensively characterized in bacteria, fungi, and animals, and the bacterial enzyme GUSA from Escherichia coli is commonly used as a reporter for gene expression studies in plants. Although endogenous GUS activity has been observed in plants, the nature and function of the enzymes involved remain elusive. Here we report on tissue-specific localization, partial purification and identification of AtGUS2, a GUS active under acidic conditions from Arabidopsis thaliana. This enzyme belongs to the GH79 family in the Carbohydrate-Active Enzymes database, which also includes mammalian heparanases that degrade the carbohydrate moieties of cell surface proteoglycans, and fungal enzymes active on arabinogalactan proteins (AGPs). We characterized a knockout insertion line (atgus2-1) and transgenic lines overexpressing AtGUS2 (Pro(35S):AtGUS2). Endogenous GUS activity assayed histochemically and biochemically was absent in atgus2-1 tissues and four times higher in Pro(35S):AtGUS2 lines. AGPs purified from atgus2-1 and Pro(35S):AtGUS2 seedlings showed higher and markedly lower glucuronic acid content, respectively. Our results suggest that endogenous GUS activity influences the sugar composition of the complex polysaccharide chains of AGPs. We also show that transgenics display hypocotyl and root growth defects compared to wild-type plants. Hypocotyl and root lengths are increased in Pro(35S):AtGUS2 seedlings, whereas hypocoyl length is reduced in atgus2-1 seedlings. These data are consistent with a role for the carbohydrate moieties of AGPs in cell growth.
- Published
- 2008
- Full Text
- View/download PDF
289. Cell wall modifications in Arabidopsis plants with altered alpha-L-arabinofuranosidase activity.
- Author
-
Chávez Montes RA, Ranocha P, Martinez Y, Minic Z, Jouanin L, Marquis M, Saulnier L, Fulton LM, Cobbett CS, Bitton F, Renou JP, Jauneau A, and Goffner D
- Subjects
- Arabidopsis genetics, Arabidopsis growth & development, DNA, Bacterial, Gene Expression, Gene Expression Profiling, Glucuronidase metabolism, Immunohistochemistry, Monosaccharides metabolism, Mutagenesis, Insertional, Oligonucleotide Array Sequence Analysis, Phenotype, Plant Stems growth & development, Arabidopsis enzymology, Arabidopsis Proteins metabolism, Cell Wall metabolism, Polysaccharides metabolism, Xylosidases metabolism
- Abstract
Although cell wall remodeling is an essential feature of plant growth and development, the underlying molecular mechanisms are poorly understood. This work describes the characterization of Arabidopsis (Arabidopsis thaliana) plants with altered expression of ARAF1, a bifunctional alpha-L-arabinofuranosidase/beta-D-xylosidase (At3g10740) belonging to family 51 glycosyl-hydrolases. ARAF1 was localized in several cell types in the vascular system of roots and stems, including xylem vessels and parenchyma cells surrounding the vessels, the cambium, and the phloem. araf1 T-DNA insertional mutants showed no visible phenotype, whereas transgenic plants that overexpressed ARAF1 exhibited a delay in inflorescence emergence and altered stem architecture. Although global monosaccharide analysis indicated only slight differences in cell wall composition in both mutant and overexpressing lines, immunolocalization experiments using anti-arabinan (LM6) and anti-xylan (LM10) antibodies indicated cell type-specific alterations in cell wall structure. In araf1 mutants, an increase in LM6 signal intensity was observed in the phloem, cambium, and xylem parenchyma in stems and roots, largely coinciding with ARAF1 expression sites. The ectopic overexpression of ARAF1 resulted in an increase in LM10 labeling in the secondary walls of interfascicular fibers and xylem vessels. The combined ARAF1 gene expression and immunolocalization studies suggest that arabinan-containing pectins are potential in vivo substrates of ARAF1 in Arabidopsis.
- Published
- 2008
- Full Text
- View/download PDF
290. Both caffeoyl Coenzyme A 3-O-methyltransferase 1 and caffeic acid O-methyltransferase 1 are involved in redundant functions for lignin, flavonoids and sinapoyl malate biosynthesis in Arabidopsis.
- Author
-
Do CT, Pollet B, Thévenin J, Sibout R, Denoue D, Barrière Y, Lapierre C, and Jouanin L
- Subjects
- Arabidopsis enzymology, Base Sequence, DNA Primers, Spectroscopy, Fourier Transform Infrared, Arabidopsis metabolism, Flavonoids biosynthesis, Lignin biosynthesis, Malates metabolism, Methyltransferases metabolism, Phenylpropionates metabolism
- Abstract
Two methylation steps are necessary for the biosynthesis of monolignols, the lignin precursors. Caffeic acid O-methyltransferase (COMT) O-methylates at the C5 position of the phenolic ring. COMT is responsible for the biosynthesis of sinapyl alcohol, the precursor of syringyl lignin units. The O-methylation at the C3 position of the phenolic ring involves the Caffeoyl CoA 3-O-methyltransferase (CCoAOMT). The CCoAOMT 1 gene (At4g34050) is believed to encode the enzyme responsible for the first O-methylation in Arabidopsis thaliana. A CCoAOMT1 promoter-GUS fusion and immunolocalization experiments revealed that this gene is strongly and exclusively expressed in the vascular tissues of stems and roots. An Arabidopsis T-DNA null mutant named ccomt 1 was identified and characterised. The mutant stems are slightly smaller than wild-type stems in short-day growth conditions and has collapsed xylem elements. The lignin content of the stem is low and the S/G ratio is high mainly due to fewer G units. These results suggest that this O-methyltransferase is involved in G-unit biosynthesis but does not act alone to perform this step in monolignol biosynthesis. To determine which O-methyltransferase assists CCoAOMT 1, a comt 1 ccomt1 double mutant was generated and studied. The development of comt 1 ccomt1 is arrested at the plantlet stage in our growth conditions. Lignins of these plantlets are mainly composed of p-hydroxyphenyl units. Moreover, the double mutant does not synthesize sinapoyl malate, a soluble phenolic. These results suggest that CCoAOMT 1 and COMT 1 act together to methylate the C3 position of the phenolic ring of monolignols in Arabidopsis. In addition, they are both involved in the formation of sinapoyl malate and isorhamnetin.
- Published
- 2007
- Full Text
- View/download PDF
291. Purification and characterization of enzymes exhibiting beta-D-xylosidase activities in stem tissues of Arabidopsis.
- Author
-
Minic Z, Rihouey C, Do CT, Lerouge P, and Jouanin L
- Subjects
- Amino Acid Sequence, Arabidopsis genetics, Arabidopsis Proteins metabolism, Electrophoresis, Polyacrylamide Gel, Kinetics, Molecular Sequence Data, Phylogeny, Protein Conformation, Sequence Homology, Amino Acid, Substrate Specificity, Xylans metabolism, Xylosidases isolation & purification, Arabidopsis enzymology, Arabidopsis Proteins genetics, Plant Stems enzymology, Xylosidases genetics, Xylosidases metabolism
- Abstract
This work describes the purification and characterization of enzymes that exhibit beta-d-xylosidase activity in stem tissues of Arabidopsis. This is the first detailed investigation that concerns the characterization of catalytic properties and sequence identity of enzymes with beta-D-xylosidase activities in a dicotyledonous plant. Three different enzymes, ARAf, XYL4, and XYL1 with apparent molecular masses of 75, 67, and 64 kD, respectively, were purified to homogeneity. ARAf was identified as a putative alpha-L-arabinofuranosidase, and XYL4 and XYL1 as putative beta-D-xylosidases using matrix-assisted laser-desorption ionization time of flight. ARAf belongs to family 51 and XYL4 and XYL1 to family 3 of glycoside hydrolases. ARAf and XYL1 have highest specificity for p-nitrophenyl-alpha-L-arabinofuranoside and XYL4 for p-nitrophenyl-beta-D-xylopyranoside and natural substrates such as xylobiose and xylotetraose. XYL4 was shown to release mainly D-Xyl from oat spelt xylan, rye arabinoxylan, wheat arabinoxylan, and oligoarabinoxylans. ARAf and XYL1 can also release D-Xyl from these substrates but less efficiently than XYL4. Moreover, they can also release L-Ara from arabinoxylans and arabinan. Overall, the results indicate that XYL4 possesses enzymatic specificity characteristic for a beta-D-xylosidase, while ARAf and XYL1 act as bifunctional alpha-L-arabinofuranosidase/beta-D-xylosidases. Analysis of the activity of these three enzymes in stem tissues at different stages of development has shown that young stems possess the highest activities for all three enzymes in comparison to the activities of the enzymes present in stems at older stages of development. High enzyme activities are most likely related to the necessary modifications of cell wall structure occurring during plant growth.
- Published
- 2004
- Full Text
- View/download PDF
292. A new Arabidopsis thaliana mutant deficient in the expression of O-methyltransferase impacts lignins and sinapoyl esters.
- Author
-
Goujon T, Sibout R, Pollet B, Maba B, Nussaume L, Bechtold N, Lu F, Ralph J, Mila I, Barrière Y, Lapierre C, and Jouanin L
- Subjects
- Alcohol Oxidoreductases genetics, Arabidopsis enzymology, Arabidopsis metabolism, Cell Wall metabolism, Cytochrome P-450 Enzyme System genetics, Esters, Flavonoids metabolism, Flowers genetics, Flowers metabolism, Gene Expression Regulation, Enzymologic, Gene Expression Regulation, Plant, Genetic Complementation Test, Methyltransferases metabolism, Mixed Function Oxygenases genetics, Mutation, Phylogeny, Plant Stems genetics, Plant Stems metabolism, Populus enzymology, Populus genetics, Solubility, Arabidopsis genetics, Arabidopsis Proteins, Lignin biosynthesis, Methyltransferases genetics
- Abstract
A promoter-trap screen allowed us to identify an Arabidopsis line expressing GUS in the root vascular tissues. T-DNA border sequencing showed that the line was mutated in the caffeic acid O-methyltransferase 1 gene (AtOMT1) and therefore deficient in OMT1 activity. Atomt1 is a knockout mutant and the expression profile of the AtOMT1 gene has been determined as well as the consequences of the mutation on lignins, on soluble phenolics, on cell wall digestibility, and on the expression of the genes involved in monolignol biosynthesis. In this mutant and relative to the wild type, lignins lack syringyl (S) units and contain more 5-hydroxyguaiacyl units (5-OH-G), the precursors of S-units. The sinapoyl ester pool is modified with a two-fold reduction of sinapoyl-malate in the leaves and stems of mature plants as well as in seedlings. In addition, LC-MS analysis of the soluble phenolics extracted from the seedlings reveals the occurrence of unusual derivatives assigned to 5-OH-feruloyl malate and to 5-OH-feruloyl glucose. Therefore, AtOMT1 enzymatic activity appears to be involved not only in lignin formation but also in the biosynthesis of sinapate esters. In addition, a deregulation of other monolignol biosynthetic gene expression can be observed in the Atomt1 mutant. A poplar cDNA encoding a caffeic acid OMT (PtOMT1) was successfully used to complement the Atomt1 mutant and restored both the level of S units and of sinapate esters to the control level. However, the over-expression of PtOMT1 in wild-type Arabidopsis did not increase the S-lignin content, suggesting that OMT is not a limiting enzyme for S-unit biosynthesis.
- Published
- 2003
- Full Text
- View/download PDF
293. T L -DNA transformation decreases ABA level.
- Author
-
Julliard J, Pelèse F, Sotta B, Maldiney R, Primard-Brisset C, Jouanin L, Pelletier G, and Miginiac E
- Abstract
The endogenous levels of ABA were measured in Agrobacterium rhizogenes A
4 Tl -DNA transformed oilseed rape (Brassica napus L. var. oleifera cv. Brutor and cv. Drakkar), cabbage (Brassica oleracea). A4 transformed tobacco (Nicotiana tabacum cv. Xanthi) and their normal counterparts, using high performance liquid chromatography and enzyme-liked immunosorbent assay. Measurements were made on different plant tissues (i. e. floral stem, terminal bud, young leaf, mature leaf, root and root tips) and ABA levels were compared in unstressed and osmotically stressed oilseed rape plants (cv. Brutor). In unstressed Plants. in each of the 5 independent transformation events studied, a significant reduction (about 65% of control) in ABA concentration was observed in all transformed plants. When subjected to an osmotic stress, TL transformed Brutor plants showed a higher ABA accumulation than untransformed plants. The change in ABA content as a consequence of TL -DNA transformation is discussed with regard to phenotype, drought resistance and adaptability.- Published
- 1993
- Full Text
- View/download PDF
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