Grapevine fruit set: Physiology of the abscission zone

Effects of ethylene and of 'anti-ethylene' compounds on the floral pedicel abscission zone in grapevines were analysed via a laboratory model consisting of isolated flowers held in Petri dishes. Our model permitted precise determination of abscission and enabled us to test a range of physiologically-active compounds including ethylene precursors, and antagonists of ethylene action. For example, a precursor of ethylene, 1-aminocyclopropane-l-carboxylic acid, had the same effect as ethylene in promoting abscission. Conversely, an inhibition of ethylene action by silver thiosulfate or an inhibition of ethylene synthesis by amino-oxyacetic acid both strongly inhibited abscission zone function. …

Analysis of resveratrol in Burgundy wines

Recent studies have shown that resveratrol (3,5,4'‐trihydroxystilbene), a phytoalexin related to grape disease resistance, could occur in American and Bordeaux wines. It was also suggested that resveratrol might have cardioprotective activities in humans, as a result of drinking wine. We report here the presence of this compound in Burgundy wines. Analysis of resveratrol in wine was carried out using gas chromatography and gas chromatography—mass spectrometry.

The climate in relation to the quality/typicity of the wines of Burgundy: the 1995 vintage

(1996). The climate in relation to the quality/typicity of the wines of Burgundy: the 1995 vintage. Journal of Wine Research: Vol. 7, No. 2, pp. 125-129.

Changes in the Phytoalexin Content of Various Vitis Spp. in Response to Ultraviolet C Elicitation

The phytoalexin production potential of three American Vitis species and that of three cultivars of Vitis vinifera were evaluated in response to UV-C irradiation. Time course changes in resveratrol, piceid, epsilon-viniferin, and pterostilbene contents were studied within 3 days after a short UV-C irradiation. Results show that the two major stilbenes accumulated as a response to UV-C elicitation are resveratrol and epsilon-viniferin, a resveratrol dehydrodimer, the concentration of both compounds usually reaching quantities >100 microgram/g of fresh weight. In contrast, piceid and pterostilbene were constantly produced in low quantities. Owing to the results obtained, the role of stilbene …

Etude des relations criblo-vasculaires entre les différents organes de la tige de la vigne (<em>Vitis vinifera</em> L.)

<p style="text-align: justify;">Etude de la structure vasculaire reliant à la tige les feuilles, vrilles, grappes et bourgeons et analyse des relations entre ces organes.</p><p style="text-align: justify;">Sur un orthostique les organes de même nature ont au moins une relation entre eux ; vrilles et grappes sont en rapport direct avec feuilles et bourgeons ; il n'y a pas de communication entre feuilles et bourgeons.</p><p style="text-align: justify;">D'un orthostique à l'autre, feuilles, vrilles et grappes ne sont en relation que par les faisceaux latéraux foliaires. Les bourgeons des deux orthostiques sont anatomiquement indépendants.</p><p style="tex…

Development of methods using phytoalexin (resveratrol) assessment as a selection criterion to screen grapevine in vitro cultures for resistance to grey mould (Botrytis cinerea)

The purpose of this research was, firstly to determine the ability of grapevine in vitro cultures to synthesize resveratrol, a stilbene-type phytoalexin that is considered to be a good marker for resistance of grapevines to Botrytis cinerea, the causal organism for grey mould. Secondly, this study sought to establish the relationship between phytoalexin production potential and resistance to Botrytis cinerea in grapevines. In this aim, resveratrol production was assessed in 13 Vitis species or cultivars. A good correlation appeared between resveratrol production by grapevine in vitro cultures and grey mould resistance except for two Vitis spp. for which no correlation was observed, thus sug…

Biological activity of resveratrol, a stilbenic compound from grapevines, against Botrytis cinerea, the causal agent for gray mold

The biological activity of resveratrol, a stilbenic compound synthesized by grapevines in response to various stresses, was reevaluated against Botrytis cinerea using a novel in vitro system that enabled direct observation of the fungus with an inverted microscope. We determined that 90 μg resveratrol/ml reduced germination of B. cinerea conidia by ca. 50%. Moreover, resveratrol was shown to significantly reduce mycelial growth of B. cinerea at concentrations ranging from 60 to 140 μg/ml. Exposure to resveratrol at concentrations ranging from 60 to 140 μg/ml resulted in cytological changes in B. cinerea, such as production of secondary or tertiary germ tubes by conidia, cytoplasmic granulat…

The production of resveratrol (3,5,4'‐trihydroxystilbene) by grapevinein vitrocultures, and its application to screening for grey mould resistance

The ability of grapevine in vitro cultures to synthesise the phytoalexin precursor resveratrol in response to ultraviolet light irradiations is investigated in order to develop methods for screening for resistance to grey mould (Botrytis cinerea Pers.) in grapevines produced as a result of somatic embryogenesis. It is demonstrated that resveratrol formation can be reproducibly induced in leaves of in vitro plantlets. Differences in the production of resveratrol among the three varieties of Vitis vinifera tested (Pinot Noir, Chardonnay and Cabernet Sauvignon) were consistent with observations regarding their field susceptibility to grey mould. The use of phytoalexin induction and of in vitro…

Potentialités de croissance et de fertilité du bourgeon latent chez la vigne (<em>Vitis vinifera</em> L.), étude réalisée de l'initiation à l'entrée en dormance

<p style="text-align: justify;">Les potentialites de croissance et de fertilité du bourgeon latent de rang 6 (<em>Vitis vinifera</em> L, cépage Pinot noir) sont étudiées grâce à des techniques de forçage pratiquées au vignoble. Ces techniques sont appliquées au bourgeon latent depuis l'état méristématique jusqu'à son entrée en dormance.</p><p style="text-align: justify;">Les potentialités de croissance importantes diminuent en même temps que la dormance s'installe.</p><p style="text-align: justify;">Nous avons montré qu'il est possible d'obtenir une certaine fertilité à partir de bourgeons qui n'ont pas encore formé d'inflorescences au moment des fo…

Metabolism of stilbene phytoalexins by Botrytis cinerea: 1. Characterization of a resveratrol dehydrodimer

Abstract Resveratrol, a grapevine phytoalexin, is metabolized by a laccase-like stilbene-oxidase of Botrytis cinerea, the causal organism for grey mould. Characterization of one major metabolite formed during this degradation process as a resveratrol dehydrodimer allowed us to precize the reaction mechanism of this enzyme on stilbenes.

Induction of Phytoalexin (Resveratrol) Synthesis in Grapevine Leaves Treated with Aluminum Chloride (AlCl3)

Production of the Phytoalexin Resveratrol by Grapes as a Response to Botrytis Attack Under Natural Conditions

Le resveratrol (3,5,4'-trihydroxystilbene) est un des mebolites de stress produit par la vigne en reponse a une infection parasitaire ou une blessure. La distribution de cette molecule dans des lesions limitees causees par Botrytis cinerea sur des grappes de raisins a maturite au vignoble a ete etudiee. Le resveratrol est localise principalement dans les fruits sains entourant les zones infectees. Cette reponse localisee contribue a limiter l'extension du pathogene tant que les conditions climatiques lui sont defavorables. Lorsque les conditions deviennent favorables; c'est-a-dire apres une periode humide et chaude, une expansion rapide des lesions est alors observee sur les fruits en depit…

Analyse des nouveaux systèmes de corrélations de croissance entre bourgeons s'établissant après une grêle chez la vigne

<p style="text-align: justify;">A la suite d'un orage de grêle très violent des dégâts très importants sur les ceps ont entraîné des modifications profondes de l'équilibre entre les différents organes et en particulier entre tous les bourgeons épargnés par la grêle. Une étude fine des facteurs de l'entrée en croissance plus ou moins active de chaque type de bourgeon a été réalisée. Un fait intéressant a pu alors être constaté : l'entrée en croissance prématurée d'un assez grand nombre de bourgeons latents principaux (d'ordre N + 2) alors encore en état de prédormance. Celle ci ne s'est le plus souvent, pas poursuivie. Elle a néanmoins entraîné, l'année suivante, des modifications de l…

The Significance of Stilbene-Type Phytoalexin Degradation by Culture Filtrates of Botrytis Cinerea in the Vine-Botrytis Interaction

Phytoalexins, antimicrobial compounds, synthesized by a plant in response to infection or a variety of stresses are known to be the most efficient way by which grapevines withstand an attack by Botrytis cinerea Pers., the causal organism for grey mould. In that plant, such responses include the production of a simple stilbene, resveratrol, and the biosynthetically related compounds, viniferins and pterostilbene. If stilbene-type phytoalexins represent a contributory factor in the resistance of grapevines to B.cinerea, the capacity of the pathogen to metabolize antifungal compounds released by the host could also play a significant role in the outcome of the interaction between grapevines an…

Evolution of the grapevine (Vitis viniferaL.) imprinted by natural and human factorsThis review is one of a selection of papers presented at the symposium onVitisat the XVII International Botanical Congress held in Vienna, Austria, in 2005.

This paper is concerned with vegetative reproduction, which is the only mode of propagation in cultivated grapevines. After a brief summary of the systematics of the Vitaceae the question of the nomenclature of cultivated grapevines is discussed. Intra-varietal variability is discussed using morphological and molecular characteristics. The origins of variation are presented: mutations, foreign nucleic acids, and memory of previous environmental conditions. Grapevines provide characteristic products, leading viticulturalists to make selections among the diversity observed in the vineyard, thus decreasing diversity. Grapevines interact with various environmental agents. One example, the natur…

Divers aspects de la fertilité de la vigne après une grêle

<p style="text-align: justify;">Following a hail storm, the question normally posed is first to what extent a repruning is beneficial, and then to evaluate the hail's effect on the following year's fertility. A careful study of the influence of hail, using numerous measurements of fertility taken during winter has allowed to determine the parameters that should be taken into account in choosing the course of action to follow.</p>

Stilbene Content of MatureVitis viniferaBerries in Response to UV-C Elicitation

A method using HPLC analysis has been used to compare the level of resveratrol and its derivatives, piceid, pterostilbene and epsilon-viniferin, in grapevine berries of three Vitis vinifera varieties. The concentration of these compounds has been evaluated in healthy and Botrytis cinerea infected grape clusters, both in natural vineyard conditions and in response to UV elicitation.

Degradation of stilbene-type phytoalexins in relation to the pathogenicity of Botrytis cinerea to grapevines

The ability of eight isolates of Botrytis cinerea to degrade the stilbene phytoalexins, resveratrol and pterostilbene, was compared with their pathogenicity to grapevines. All strains which degraded resveratrol and pterostilbene were highly or moderately pathogenic to in vitro cultures of grapevines (Vitis rupestris) after inoculation with agar disks containing mycelium, while those which were unable to degrade phytoalexins were non-pathogenic. In all cases, the hydroxystilbene-degrading activity was related to the presence of laccase activity in the culture filtrates, as shown by using syringaldazine as substrate. The role of laccase-mediated degradation of phytoalexins in relation to path…

CHEMICAL INDUCTION OF PHYTOALEXIN SYNTHESIS IN GRAPEVINES: APPLICATION TO THE CONTROL OF GREY MOULD IN THE VINEYARD

Use of carbon dioxide enrichment to obtain adult morphology of grapevinein vitro

A procedure has been developed forin vitro propagation ofVitis vinifera ‘Pinot noir’ from lateral-bud cuttings under high CO2 concentration (1200 µmol mol−1). Because of inhibition of rooting by CO2, this procedure requires a rooting pre-culture of explants on medium with sucrose before the CO2-enriched culture on sucrose-free medium. Shoot growth was enhanced by CO2 enrichment as a result of both a higher rate of leaf production and greater internode elongation. Leaf expansion and tendril growth were promoted and better rooting was obtained. The more significant effect of CO2 enrichment was to promote adult morphology with, in particular, the tendril pattern. Thus, for the first time, grap…