9 results on '"Baissac, Y"'
Search Results
2. Phenolic compounds of olive-tree leaves and their relationship with the resistance to the leaf-spot disease caused by Spilocaea oleaginea
- Author
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Rahioui, B., Zine El Aabidine, A., Baissac, Y., El Boustani, E., Khadari, Bouchaib, Jay-Allemand, C., El Modafar, C., Université Cadi Ayyad [Marrakech] (UCA), Université Montpellier 2 - Sciences et Techniques (UM2), Développement et amélioration des plantes (UMR DAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)
- Subjects
TAVELURE DE L'OLIVIER ,MALADIE DE L'OEIL DE PAON ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,food and beverages ,OLIVIER ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,SPILOCAEA OLEAGINEA ,PHENOLIC COMPOUNDS ,OLEA EUROPEA ,MARQUEUR BIOCHIMIQUE ,RESISTANCE - Abstract
UMR DAP Equipe AFEF; International audience; Phenolic compounds are associated with the olive tree resistance to the leaf-spot disease caused by Spilocaea oleaginea were studied in different resistant, susceptible and intermediate cultivars. The HPLC analysis highlights 33 phenolic compounds distinguished according to their chromatographic and spectral characteristics into five phenolic families (hydroxycinnamic derivatives, flavonoids, verbascoside derivatives, tyrosol derivatives, oleuropein derivatives). The phenolic extract of the olive-tree is dominated by ten major compounds identified as rutin, luteolin-7-glucoside, oleuropein, versbacoside, tyrosol, apigenin and four other phenolic compounds not completely identified (oleuropein derivative, hydroxycinnamic derivative and two flavonol monoglucosides). No qualitative difference was observed between cultivars. However, the principal components analysis highlights two multifactorial components distinguishing the various cultivars according to their behaviour to the disease. The first component, identified as oleuropein aglycone, a hydroxycinnamic derivative and a flavonol monoglucoside contents, clearly distinguished the resistant cultivars from the susceptible and intermediately resistant cultivars. The resistant cultivars contain higher contents. The second component, identified as tyrosol derivative and an oleuropein derivative contents, distinguished the susceptible cultivars from the intermediately resistant cultivar which presents the highest contents. The role of these phenolic compounds in the defense and their use as biochemical markers in olive-tree resistance to S. oleaginea is discussed
- Published
- 2009
3. 4-Hydroxyisoleucine: a novel amino acid potentiator of insulin secretion
- Author
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Sauvaire, Y., primary, Petit, P., additional, Broca, C., additional, Manteghetti, M., additional, Baissac, Y., additional, Fernandez-Alvarez, J., additional, Gross, R., additional, Roye, M., additional, Leconte, A., additional, Gomis, R., additional, and Ribes, G., additional
- Published
- 1998
- Full Text
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4. Salicylic acid mediated by the oxidative burst is a key molecule in local and systemic responses of cotton challenged by an avirulent race of Xanthomonas campestris pv malvacearum.
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Martinez, C, Baccou, J C, Bresson, E, Baissac, Y, Daniel, J F, Jalloul, A, Montillet, J L, Geiger, J P, Assigbetsé, K, and Nicole, M
- Abstract
We analyzed the production of reactive oxygen species, the accumulation of salicylic acid (SA), and peroxidase activity during the incompatible interaction between cotyledons of the cotton (Gossypium hirsutum) cv Reba B50/Xanthomonas campestris pv malvacearum (Xcm) race 18. SA was detected in petioles of cotyledons 6 h after infection and 24 h post inoculation in cotyledons and untreated leaves. The first peak of SA occurred 3 h after generation of superoxide (O(2)(.-)), and was inhibited by infiltration of catalase. Peroxidase activity and accumulation of SA increased in petioles of cotyledons and leaves following H(2)O(2) infiltration of cotyledons from 0.85 to 1 mM. Infiltration of 2 mM SA increased peroxidase activity in treated cotyledons and in the first leaves, but most of the infiltrated SA was rapidly conjugated within the cotyledons. When increasing concentrations of SA were infiltrated 2. 5 h post inoculation at the beginning of the oxidative burst, the activity of the apoplastic cationic O(2)(.-)-generating peroxidase decreased in a dose-dependent manner. We have shown that during the cotton hypersensitive response to Xcm, H(2)O(2) is required for local and systemic accumulation of SA, which may locally control the generation of O(2)(.-). Detaching cotyledons at intervals after inoculation demonstrated that the signal leading to systemic accumulation of SA was emitted around 3 h post inoculation, and was associated with the oxidative burst. SA produced 6 h post infection at HR sites was not the primary mobile signal diffusing systemically from infected cotyledons.
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- 2000
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5. 4-Hydroxyisoleucine: effects of synthetic and natural analogues on insulin secretion
- Author
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Broca, C., Manteghetti, M., Gross, R., Baissac, Y., Jacob, M., Petit, P., Sauvaire, Y., and Ribes, G.
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- 2000
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6. Resistance of olive tree to Spilocaea oleagina is mediated by the synthesis of phenolic compounds
- Author
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Aabidine, A. Z. E., Baissac, Y., Abdelmajid Moukhli, Jay-Allemand, C., Khadari, B., Modafar, C. E., Université Cadi Ayyad [Marrakech] (UCA), Université Montpellier 2 - Sciences et Techniques (UM2), Institut national de la recherche agronomique [Maroc] (INRA Maroc), Développement et amélioration des plantes (UMR DAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)
- Subjects
résistance aux maladies ,OLIVE TREE ,SPILOCAEA OLEAGINA ,RESISTANCE ,MULTIFACTORIAL PHENOLICS ,MOROCCO ,OLIVIER ,OLEA EUROPEA ,TAVELURE DE L'OLIVIER ,MALADIE EN OEIL DE PAON ,afrique ,composé phénolique ,food and beverages ,pays méditerranéen ,croisement ,enzyme ,maroc ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,génotype - Abstract
E-mail Addresses: elmodafar@fstg-marrakech.ac.ma Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; To understand the resistance of the olive tree to the leaf-spot disease caused by Spilocaea oleagina, the constitutive and postinfectional synthesis phenolic compounds of the leaves were analyzed by HPLC in 110 genotypes F1 (susceptible cultivar “Picholine marocaine” x resistant cultivar “Picholine du Languedoc”) presenting of the differential behaviours to this disease (highly resistant, resistant, intermediate, susceptible & highly susceptible genotypes). The HPLC analysis distinguished 15 majors phenolic compounds according to their chromatographic and spectral characteristics into five phenolic families (hydroxycinnamic derivatives, flavonoids, verbascoside derivatives, tyrosol derivatives, oleuropein derivatives). No qualitative difference was observed between cultivars. Principal components analysis (PCA) highlighted three multifactorial components distinguishing the various genotypes according to their behaviour to the disease. These components were determined by the postinfectional contents of oleuropein and rutin and by the constitutive contents of tyrosol and its derivatives. The tyrosol and its derivatives were associated with constitutive resistance, whereas the oleuropein and rutin were associated with induced resistance. These results suggest that the activity ratio of the enzymes implied in various biosynthesis ways of these phenolic compounds and/or the expression rate of the corresponding genes would be at the origin of the resistance degree of olive tree to S. oleagina.
7. Dynamics of flavonol accumulation in leaf tissues under different UV-B regimes in Centella asiatica (Apiaceae).
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Bidel LP, Chomicki G, Bonini F, Mondolot L, Soulé J, Coumans M, La Fisca P, Baissac Y, Petit V, Loiseau A, Cerovic ZG, Gould KS, and Jay-Allemand C
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- Apiaceae radiation effects, Plant Leaves radiation effects, Apiaceae metabolism, Flavonols metabolism, Plant Leaves metabolism, Ultraviolet Rays
- Abstract
Main Conclusion: A cumulative effect of UV-B doses on epidermal flavonol accumulation was observed during the first week of a time course study in Centella asiatica (Apiaceae). However, once flavonol levels had peaked, additional accumulation was possible only if higher daily UV-B irradiances were applied. We aimed to understand the dynamics of flavonol accumulation in leaf tissues using non-destructive spectroscopy and HPLC-mass spectrometry. When leaves that had grown without UV-B were given brief daily exposures to low-irradiance UV-B, they accumulated flavonols, predominantly kaempferol-3-O-β-D-glucuronopyranoside and quercetin-3-O-β-D-glucuronopyranoside, in their exposed epidermis, reaching a plateau after 7 days. More prolonged UV-B exposures or higher doses eventually augmented flavonol concentrations even in non-exposed tissues. If UV-B irradiance was subsequently reduced, leaves appeared to lose their ability to accumulate further flavonols in their epidermis even if the duration of daily exposure was increased. A higher irradiance level was then necessary to further increase flavonol accumulation. When subsequently acclimated to higher UV-B irradiances, mature leaves accumulated less flavonols than did developing ones. Our study suggests that levels of epidermal flavonols in leaves are governed primarily by UV-B irradiance rather than by duration of exposure.
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- 2015
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8. The velamen protects photosynthetic orchid roots against UV-B damage, and a large dated phylogeny implies multiple gains and losses of this function during the Cenozoic.
- Author
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Chomicki G, Bidel LPR, Ming F, Coiro M, Zhang X, Wang Y, Baissac Y, Jay-Allemand C, and Renner SS
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- Acyltransferases genetics, Acyltransferases metabolism, Apigenin metabolism, Crosses, Genetic, Flavonoids metabolism, Gene Duplication, Gene Expression Regulation, Plant radiation effects, Glucosides metabolism, Orchidaceae genetics, Stress, Physiological radiation effects, Time Factors, Orchidaceae physiology, Orchidaceae radiation effects, Photosynthesis, Phylogeny, Plant Roots anatomy & histology, Plant Roots radiation effects, Ultraviolet Rays
- Abstract
UV-B radiation damage in leaves is prevented by epidermal UV-screening compounds that can be modulated throughout ontogeny. In epiphytic orchids, roots need to be protected against UV-B because they photosynthesize, sometimes even replacing the leaves. How orchid roots, which are covered by a dead tissue called velamen, avoid UV-B radiation is currently unknown. We tested for a UV-B protective function of the velamen using gene expression analyses, mass spectrometry, histochemistry, and chlorophyll fluorescence in Phalaenopsis × hybrida roots. We also investigated its evolution using comparative phylogenetic methods. Our data show that two paralogues of the chalcone synthase (CHS) gene family are UV-B-induced in orchid root tips, triggering the accumulation of two UV-B-absorbing flavonoids and resulting in effective protection of the photosynthetic root cortex. Phylogenetic and dating analyses imply that the two CHS lineages duplicated c. 100 million yr before the rise of epiphytic orchids. These findings indicate an additional role for the epiphytic orchid velamen previously thought to function solely in absorbing water and nutrients. This new function, which fundamentally differs from the mechanism of UV-B avoidance in leaves, arose following an ancient duplication of CHS, and has probably contributed to the family's expansion into the canopy during the Cenozoic., (© 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.)
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- 2015
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9. Steroid saponins from fenugreek seeds: extraction, purification, and pharmacological investigation on feeding behavior and plasma cholesterol.
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Petit PR, Sauvaire YD, Hillaire-Buys DM, Leconte OM, Baissac YG, Ponsin GR, and Ribes GR
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- Animals, Body Weight, Chromatography, High Pressure Liquid, Diabetes Mellitus, Experimental, Gas Chromatography-Mass Spectrometry, Kinetics, Male, Rats, Rats, Wistar, Saponins pharmacology, Steroids pharmacology, Cholesterol blood, Eating drug effects, Saponins isolation & purification, Seeds chemistry, Steroids isolation & purification
- Abstract
The seeds of fenugreek (Trigonella foenum graecum L.) are traditionally assumed to have restorative properties. We have recently shown that a fenugreek seed extract containing steroid saponins increased food consumption and induced hypocholesterolemia in rats. This study aims to investigate the specific role of purified steroid saponins in these properties. For this purpose, an original technique for extraction and purification of steroid saponins was carried out. Thereafter, the effects of these steroid saponins were investigated on feeding behavior and metabolic endocrine changes in normal and diabetic rats. All the steroid saponins (furostanol type) were extracted from the seeds and separated from all other constituents of the entire extract by using several purification procedures to give an extract containing at least 90% of steroid saponins. Pharmcological experiments were performed in vivo in normal and streptozotocin diabetic rats: steroid saponins were administered chronically mixed with food (12.5 mg/day per 300 g body weight). Our data show that the treatment with steroid saponins significantly increased food intake and the motivation to eat in normal rats, while modifying the circadian rhythm of feeding behavior; it also stabilized the food consumption in diabetic rats, which resulted in a progressive weight gain in these animals, in contrast to untreated diabetic controls. Both in normal and diabetic rats, steroid saponins decreased total plasma cholesterol without any change in triglycerides. In conclusion, the present work reports a clear methodology to obtain all the steroid saponins and demonstrates that these saponins enhance food consumption and motivation to eat, and reduce plasma cholesterol levels in rats.
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- 1995
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