62 research outputs found
Les vertus insoupconnées du marc de raisin
Lors des vendanges, le pressage des grappes laisse un résidu appelé marc de raisin. A l’heure actuelle, le marc de raisin entre dans la composition de cosmétiques, de compléments alimentaires et médicinaux. Des chercheurs de l’Université Blaise Pascal ont découvert deux nouvelles propriétés du marc rouge qui conduisent à des applications dans le domaine de la protection des végétaux. Ces découvertes ont fait l’objet de deux brevets et ouvrent une voie nouvelle à la valorisation des produits dérivés de la vigne
Grape marc extract causes early perception events, defence reactions and hypersensitive response in cultured tobacco cells
Plant Physiol. Biochem. ISI Document Delivery No.: AE5EJ Times Cited: 0 Cited Reference Count: 34 Benouaret, R. Goujon, E. Goupil, P. FUI: Fonds Unique Interministeriel We thank Celine Sac for help with the tobacco cell cultures and laboratory assistance. This work was supported by grants from the FUI: Fonds Unique Interministeriel. Elsevier france-editions scientifiques medicales elsevier ParisInternational audienceGrape marc extract (GME) showed elicitor activity on suspension-cultured cells of tobacco. The BY-2 cells reacted to GME (0.25% and 0.125%) with a long-sustained pH rise in their growth medium. Using EGTA or LaCl3, we showed that extracellular alkalinization depended on Ca2+ mobilization. The tobacco BY-2 cells challenged with GME promoted cell death and the upregulation of defence-related genes such as PR3, PAL and CCoAOMT. Cell death rate was quantified using an experimental calibrated Evans Blue assay. The GME-induced cell death was dose-dependent and occurred in 24 h. Longer exposure increased the extent of tobacco cell death. To investigate a potential hypersensitive reaction, we tested the effect of various inhibitors of protein synthesis (cycloheximide) and proteases (aprotinin, pepstatin and E-64) on GME-induced cell death. All these chemicals reduced GME-induced cell death rate in 30 min. Overall, our findings indicate that GME elicits early perception events, defence reactions and cell death requiring protein synthesis and proteases
Expression of stress-related genes in tomato plants exposed to arsenic and chromium in nutrient solution
International audienceThe molecular responses of hydroponically cultivated tomato plants to As(V) or Cr(VI) were assessed by transcript accumulation analysis of genes coding for products potentially involved in heavy metal tolerance. A quantitative real-time PCR experiment was performed with Hsp90-1, MT2- and GR1-like protein genes using RNA isolated from tomato roots or shoots treated for 24 h with As(V) or Cr(VI) at concentrations ranging from 80 to 640 ÎĽM. Both transient metallic treatments induced Hsp90-1 transcript accumulation in tomato plants. MT2- and GR1-like transcripts accumulated in tomato roots treated with As(V) but were only slightly affected by Cr(VI) treatment. Tomatoes showed phenotypic symptoms to heavy metal toxicity when plants were exposed to Cr(VI) but not As(V). Plant lethality was observed at 1280 ÎĽM Cr(VI), indicating that tomatoes were more tolerant to As than Cr stress under the experimental conditions used here
Grape marc extract acts as elicitor of plant defence responses
International audiencePlant protection based on novel alternative strategies is a major concern in agriculture to sustain pest management. The marc extract of red grape cultivars reveals plant defence inducer properties. Treatment with grape marc extract efficiently induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining of tobacco leaves. Examination of the infiltration zone and the surrounding areas under UV light revealed the accumulation of autofluorescent compounds. Both leaf infiltration and a foliar spray of the red grape extract on tobacco leaves induced defence gene expression. The PR1 and PR2 target genes were upregulated locally and systemically in tobacco plants following grape marc extract treatment. The grape extract elicited an array of plant defence responses making this natural compound a potential phytosanitary product with a challenging issue and a rather attractive option for sustainable agriculture and environmentally friendly practices
Etude moleculaire d'un marqueur biochimique de la levee de dormance des tubercules de topinambour (Helianthus tuberosus L.) : l'invertase
SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
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La saisonnalité des produits touristiques hivernaux de plein air de la région de Charlevoix: Stratégies et innovations
Le tourisme hivernal est une des priorités de développement du ministère du Tourisme du Québec. Toutefois, dans les régions, dont celle de Charlevoix, plusieurs enjeux affectent la croissance du tourisme hivernal. Parmi ceux-ci, la saisonnalité représente une problématique centrale, et ce, tant au niveau social qu’économique. Afin de réduire les effets négatifs de la saisonnalité en période hivernale, cette recherche vise à étudier et recommander des stratégies d’innovation touristique qui pourraient être utilisées pour développer ou améliorer des produits hivernaux de plein air dans la région de Charlevoix.
La communication présentera les principales avancées théoriques sur les concepts d’innovation, de saisonnalité et du tourisme hivernal, ainsi que les résultats issus d’une recherche empirique basée sur trois méthodes de recherche (analyse de contenu de sites web de destinations comparables, entretiens avec des gestionnaires de sites touristiques hivernaux et observation in situ)
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