Search results for "botrytis"
showing 10 items of 104 documents
Biological activity of resveratrol, a stilbenic compound from grapevines, against Botrytis cinerea, the causal agent for gray mold
1997
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…
Degradation of stilbene-type phytoalexins in relation to the pathogenicity of Botrytis cinerea to grapevines
1996
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…
Stilbene Content of MatureVitis viniferaBerries in Response to UV-C Elicitation
2001
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.
The Significance of Stilbene-Type Phytoalexin Degradation by Culture Filtrates of Botrytis Cinerea in the Vine-Botrytis Interaction
1993
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…
The production of resveratrol (3,5,4'‐trihydroxystilbene) by grapevinein vitrocultures, and its application to screening for grey mould resistance
1992
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…
Development of methods using phytoalexin (resveratrol) assessment as a selection criterion to screen grapevine in vitro cultures for resistance to gr…
1995
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…
Metabolism of stilbene phytoalexins by Botrytis cinerea: 1. Characterization of a resveratrol dehydrodimer
1998
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.
Production of the Phytoalexin Resveratrol by Grapes as a Response to Botrytis Attack Under Natural Conditions
1995
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…
Biological control ofBotrytis cinereacausing grey mould disease of grapevine and elicitation of stilbene phytoalexin (resveratrol) by a soil bacterium
1998
Botrytis cinerea Pers. was found to be highly pathogenic to the grapevine plant, producing the characteristic grey mould symptoms within 7 days of inoculation on vitroplants. A bacterial strain, isolated from soil, belonging to the genus Bacillus was found to be an antagonist of this disease causing fungus. The fungal attack on the grapevine acts as an elicitor to the production of phytoalexines like resveratrol. This compound was also formed when the leaves of the grapevine vitroplants were inoculated with the bacteria alone, and this activity was enhanced when a mixture of the pathogen and the antagonist bacteria was applied. Since resveratrol in wine is considered to be beneficial to hum…
Determinación de marcas epigenéticas en genesimplicados en la respuesta temprana a Botrytis cinerea de Arabidopsis thaliana y Solanum lycopersicum
2018
Existen en estudios recientes realizados en plantas, evidencias que vinculan la presencia de modificaciones epigenéticas con su respuesta a estreses bióticos. Sin embargo, dentro de estos estreses no se encuentra a penas información sobre patógenos necrótrofos. En esta tesis se exploran las posibles alteraciones en la estructura cromatinica que plantas de las especies Arabidopsis thaliana y Solanum lycopersicum (tomate) podrían experimentar en varios de sus genes expresados en la respuesta a la infección por Botrytis cinerea, un hongo necrótrofo. Se plantea para ellos la puesta a punto de un protocolo de extracción de cromatina y de inmunoprecipitación de la misma (ChIP) y, se relatan las d…