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Jeanpaul Roustan - One of the best experts on this subject based on the ideXlab platform.
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effects of eutypine a toxin from Eutypa lata on plant cell plasma membrane possible subsequent implication in disease development
Plant Physiology and Biochemistry, 2001Co-Authors: Benignee Amborabe, Jeanpaul Roustan, Pierrette Fleuratlessard, Janine Bonmort, Gabriel RoblinAbstract:Abstract Eutypine, 4-hydroxy-3-(3-methyl-3-butene-1-ynyl) benzaldehyde, is a toxin produced by Eutypa lata, the causal agent of Eutypa dieback. An essential target of eutypine action lies at the plasmalemma as shown by the data obtained during this study on three experimental models (Beta vulgaris, Mimosa pudica, Vitis vinifera). The fungal toxin at 100 μM triggered a rapid dose-dependent hyperpolarization of the membrane potential in M. pudica pulvinar cells. It also enhanced proton permeability in plant tissues or in purified plasma membrane vesicles (PMV) without modification of the H+-ATPase activity. As a physiological consequence, eutypine hindered sucrose and valine absorption by PMV and plant tissues. In all these situations, eutypine behaved like a protonophoric compound, such as dinitrophenol (DNP) used at 10 μM, and acted specifically since eutypinol, an inactive derivative, only triggered very limited effects at a 100-μM concentration. Eutypine did not modify phenylalanine ammonia lyase (PAL, EC 4.3.1.5) activity, suggesting that its toxic action has no after-effect on the secondary metabolism.
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purification and characterization of a nadph dependent aldehyde reductase from mung bean that detoxifies eutypine a toxin from Eutypa lata
Plant Physiology, 1999Co-Authors: Segolene Colrat, Alain Latche, Monique Guis, Jeanclaude Pech, Mondher Bouzayen, J Fallot, Jeanpaul RoustanAbstract:Eutypine (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzaldehyde) is a toxin produced by Eutypa lata , the causal agent of Eutypa dieback in the grapevine ( Vitis vinifera ). Eutypine is enzymatically converted by numerous plant tissues into eutypinol (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl alcohol), a metabolite that is nontoxic to grapevine. We report a four-step procedure for the purification to apparent electrophoretic homogeneity of a eutypine-reducing enzyme (ERE) from etiolated mung bean ( Vigna radiata ) hypocotyls. The purified protein is a monomer of 36 kD, uses NADPH as a cofactor, and exhibits a K m value of 6.3 μm for eutypine and a high affinity for 3- and 4-nitro-benzaldehyde. The enzyme failed to catalyze the reverse reaction using eutypinol as a substrate. ERE detoxifies eutypine efficiently over a pH range from 6.2 to 7.5. These data strongly suggest that ERE is an aldehyde reductase that could probably be classified into the aldo-keto reductase superfamily. We discuss the possible role of this enzyme in eutypine detoxification.
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a novel nadph dependent aldehyde reductase gene from vigna radiata confers resistance to the grapevine fungal toxin eutypine
Plant Journal, 1998Co-Authors: Pedro Guillen, Segolene Colrat, Monique Guis, Mondher Bouzayen, J Fallot, Jeanpaul Roustan, Corine Deswarte, Gracia Martinezreina, Sylvie Dalmayrac, Jeanclaude PechAbstract:Eutypine, 4-hydroxy-3-(3-methyl-3-butene-1-ynyl) benzyl aldehyde, is a toxin produced by Eutypa lata, the causal agent of Eutypa dieback of grapevines. It has previously been demonstrated that tolerance of some cultivars to this disease was correlated with their capacity to convert eutypine to the corresponding alcohol, eutypinol, which lacks phytotoxicity. We have thus purified to homogeneity a protein from Vigna radiata that exhibited eutypine-reducing activity and have isolated the corresponding cDNA. This encodes an NADPH-dependent reductase of 36 kDa that we have named Vigna radiata eutypine-reducing enzyme (VR-ERE), based on the capacity of a recombinant form of the protein to reduce eutypine into eutypinol. The strongest homologies (86.8%) of VR-ERE at the amino acid level were found with CPRD14, a drought-inducible gene of unknown function, isolated from Vigna unguiculata and with an aromatic alcohol dehydrogenase (71.7%) from Eucalyptus gunnii. Biochemical characterization of VR-ERE revealed that a variety of compounds containing an aldehyde group can act as substrates. However, the highest affinity was observed with 3-substituted benzaldehydes. Expression of a VR-ERE transgene in Vitis vinifera cells cultured in vitro conferred resistance to the toxin. This discovery opens up new biotechnological approaches for the generation of grapevines resistant to Eutypa dieback.
Karine Loridon - One of the best experts on this subject based on the ideXlab platform.
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Effect of ectopic expression of the eutypine detoxifying gene Vr-ERE in transgenic apple plants
Plant Cell Tissue and Organ Culture, 2011Co-Authors: Elisabeth Chevreau, Fabrice Dupuis, Jean-paul Taglioni, Sophie Sourice, Raphael Cournol, C. Deswartes, A. Bersegeay, Julie Descombin, Myriam Siegwart, Karine LoridonAbstract:The development of alternative selection systems without antibiotic resistance genes is a key issue to produce safer and more acceptable transgenic plants. Eutypine is a toxin produced by Eutypa lata, the causal agent of Eutypa dieback of grapevine, which is detoxified in mung bean (Vigna radiata) by the gene Vr-ERE. Many phytotoxic compounds containing an aldehyde group can act as substrates for the Vr-ERE enzyme. The aim of the present work was to evaluate the effects of the overexpression of Vr-ERE in transgenic apple plants, as a first step towards the development of an alternative selection system. Viable transgenic apple clones expressing Vr-ERE were produced from the cultivar Greensleeves under kanamycin selection. Although the Vr-ERE transgene was normally expressed at the RNA and protein levels, the increase in aldehyde reductase activity tested on a range of potential substrates was very low in these clones. None of them revealed a significant increase in tolerance to toxic aldehydes compared to their non-transgenic control. This work with transgenic apple plants overexpressing the detoxifying gene Vr-ERE illustrates some of the difficulties in developing an alternative selection pressure
W D Gubler - One of the best experts on this subject based on the ideXlab platform.
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diversity of diatrypaceous fungi associated with grapevine canker diseases in california
Mycologia, 2010Co-Authors: Florent P. Trouillas, J R Urbeztorres, W D GublerAbstract:Eutypa lata is the most common diatrypaceous fungus in grapevine cankers. This study was undertaken to determine the presence and diversity of other members of the Diatrypaceae in grapevines in California. We isolated into pure culture 11 species of Diatrypaceae from the wood of diseased grapevines including Cryptosphaeria pullmanensis, Cryptovalsa ampelina, Diatrype oregonensis, D. stigma, D. whitmanensis, Diatrype sp., Diatrypella verrucaeformis and four putative species of Eutypella. Species were identified or grouped morphologically and by phylogenetic analyses of the complete sequence of the internal transcribed spacer (ITS) of the rDNA and β-tubulin gene. Diatrypaceous fungi also occurred frequently on the native flora surrounding vineyards, thus serving as possible inoculum sources for these putative pathogens.
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occurrence of botryosphaeria obtusa b dothidea and b parva associated with grapevine trunk diseases in castilla y leon region spain
Plant Disease, 2006Co-Authors: J R Urbeztorres, W D Gubler, H Pelaez, Y Santiago, C Martin, C MorenoAbstract:Between 2000 and 2004, 176 vineyards were surveyed for disease symptoms throughout the main grapevine-production areas of Bierzo, Cigales, Ribera del Duero, Rueda, and Toro in the Castilla y Leon region of Spain. Symptoms resembling Eutypa dieback, such as stunted chlorotic shoots, deformed leaves with necrotic areas, and typical wedge-shaped cankers in the wood, were observed in 80% of surveyed vineyards. The second most common disease observed was esca. The mild form of esca, interveinal chlorosis or reddened patterns on the leaves, was observed in 35% of surveyed vineyards. Severe esca symptoms that include sudden defoliation of some or all parts of the vine followed by shriveling of fruit clusters were observed in vineyards during very hot and dry summer periods. Wood from vines with esca was yellowish, soft, and often partially or completely surrounded by necrotic wood. Black vascular streaking in the wood was also observed in some vines with esca. Samples of wood from vines with symptoms of Eutypa d...
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use of boron for the control of Eutypa dieback of grapevines
Plant Disease, 2005Co-Authors: Philippe E Rolshausen, W D GublerAbstract:ABSTRACT Eutypa dieback is a perennial canker disease of grapevine (Vitis vinifera) caused by Eutypa lata. The fungus produces ascospores, which infect grapevines through pruning wounds during the dormant season. Management of the disease has been achieved with fungicide applications during the dormant period. However, no effective fungicide was available for this purpose after Benlate was withdrawn from the market. Boric acid (17.5% a.i. boron), a potential alternative to Benlate, was tested in the present study against E. lata. The EC50 values for inhibition of mycelial growth and ascospore germination were 125 and 475 μg of boric acid per ml (22 and 83 μg a.i./ml), respectively. Two boron-based treatments were developed and tested in vitro and in four field trials during 2001 to 2003. One product, biopaste, contained 5% boric acid (8.75 mg a.i./ml) in a commercial paste. The second product, bioshield, contained 5% boric acid in a spore suspension of Cladosporium herbarum. Both products significantly re...
Sosnowski M. - One of the best experts on this subject based on the ideXlab platform.
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Developing pruning wound protection strategies for managing Eutypa dieback
'Wiley', 2017Co-Authors: Ayres M., Wicks T., Scott E., Sosnowski M.Abstract:Background and Aims: Eutypa dieback is an economically important disease of grapevines and a major threat to vineyard longevity throughout the world. Developing effective preventative strategies offers the best means of control. In this study, pruning wound protectants and various spray applications were evaluated for their ability to prevent infection by ascospores of Eutypa lata. Methods and Results: Fungicides and natural alternative treatments were applied by hand to grapevine pruning wounds in winter prior to inoculation with E. lata. In a series of greenhouse and field experiments, tebuconazole, pyraclostrobin, fluazinam, garlic extract and lactoferrin significantly reduced infection. A range of tractor-driven sprayers was used to apply tebuconazole to pruning wounds, and those which provided good coverage reduced infection by E. lata to a level similar to that when tebuconazole was applied with a paintbrush. Conclusion: Eutypa dieback can be controlled with several fungicides and natural treatments. Tractor-driven sprayers, which by design or modification can efficiently deliver maximum possible coverage at high output rates, can be used for application of pruning wound treatments. Significance of the Study: Results of this study contributed to registration of fungicides for use as pruning wound treatments to control E. lata in Australia. Demonstrating the ability of tractor-driven sprayers to apply treatments effectively has led to greater industry adoption of dormant treatments and may decrease the future impact of Eutypa dieback.M.R. Ayres, T.J. Wicks, E.S.Scott and M.R. Sosnows
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Effect of the inoculum dose of three grapevine trunk pathogens on the infection of artificially inoculated pruning wounds
Unione Fitopatologica Mediterranea, 2015Co-Authors: Elena G., Lecomte P., Sosnowski M., Garcia-figueres F., Ayres M., Benetreau C., Luque J.Abstract:This study assessed the infection rates of different spore inoculum doses of the grapevine trunk pathogens Diplodia seriata, Phaeomoniella chlamydospora and Eutypa lata following artificial inoculation of pruning wounds. Potted vines of cv. Tempranillo were inoculated with doses ranging from 10 to 4000 conidia per wound of D. seriata and P. chlamydospora and led to recovery percentages of 10–100% for D. seriata and 16–94% for P. chlamydospora. Eutypa lata, when inoculated onto wounds of vines in a mature vineyard (cv. Shiraz) and on detached canes (cv. Cabernet Sauvignon) with a dose range of 10 to 1000 ascospores per wound, led to recovery percentages of 17–95%. In the field assay, there was no difference in recovery from wounds that were exposed to single or double inoculations with the same total spore dose, or between canes that were harvested 7 or 11 months after inoculation. The results obtained in this study showed significant variability in pathogen recovery between trials, comparable with that reported previously, which suggests that factors such as pathogen virulence, environmental parameters and experimental conditions may influence the infection process. According to this study, in order to obtain optimal recovery percentages of 50–70% for robust evaluation of pruning wound treatments, dose ranges of 100-1000 conidia of D. seriata, 100–2000 conidia of P. chlamydospora, and 100–500 ascospores of E. lata per wound would be required.Georgina Elena, Mark R. Sosnowski, Matthew R. Ayres, Pascal Lecomte, Celine Benetreau, Francesc Garcia-Figueres, Jordi Luqu
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Pathogenicity of Diatrypaceous fungi on grapevines in Australia
'Scientific Societies', 2013Co-Authors: Pitt W., Savocchia S., Gubler W., Trouillas F., Sosnowski M.Abstract:In addition to Eutypa lata, which causes Eutypa dieback, numerous other fungi in the Diatrypaceae family have been isolated from diseased grapevines (Vitis vinifera) and other woody hosts. Pathogenicity trials comprising 70 strains of diatrypaceous fungi representing nine species in six genera were conducted to determine whether these fungi, collected in Australia, were pathogenic to grapevines. When inoculated into wounded trunks of ‘Cabernet Sauvignon’, eight species, including E. lata, E. leptoplaca, Cryptovalsa ampelina, C. rabenhorstii, Eutypella citricola, E. microtheca, Diatrypella vulgaris, and a Diatrype sp. produced necrotic lesions significantly longer than on controls. In addition, all nine species (including a Cryptosphaeria sp.) were reisolated from the margins of developing lesions and at varying distances above and below the point of inoculation. Diatrypaceous fungi were frequently isolated from asymptomatic or otherwise healthy tissue several centimeters ahead of the disease margin. Methods to control diseases associated with diatrypaceous fungi must take into account their propensity to colonize woody tissues ahead of or in the absence of visible symptoms. Current recommendations for the management of Eutypa dieback using remedial surgery and pruning wound protection appear sufficient for the control of the other diatrypaceous fungi included in this study.Wayne M. Pitt, Florent P. Trouillas, Walter D. Gubler, Sandra Savocchia, Mark R. Sosnowsk
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Genetic structure of the fungal grapevine pathogen Eutypa lata from four continents
'Wiley', 2012Co-Authors: Travadon R., Halleen F., Lecomte P., Sosnowski M., Baumgartner K., Rolshausen P., Gubler W., Péros J.Abstract:The generalist ascomycete fungus Eutypa lata causes Eutypa dieback of grapevine (Vitis vinifera) worldwide. To decipher the cosmopolitan distribution of this fungus, the population genetic structure of 17 geographic samples was investigated from four continental regions (Australia, California, Europe and South Africa), based on analysis of 293 isolates genotyped with nine microsatellite markers. High levels of haplotypic richness (R = 0·91–1) and absence of multilocus linkage disequilibrium among loci supported the preponderance of sexual reproduction in all regions examined. Nonetheless, the identification of identical multilocus haplotypes with identical vegetative compatibility groups, in some vineyards in California and South Africa, suggests that asexual dispersal of the fungus among neighbouring plants could be a rare means of disease spread. The greatest levels of allelic richness (A = 4·89–4·97) and gene diversity (H = 0·66–0·69) were found in Europe among geographic samples from coastal areas surrounding the Mediterranean Sea, whereas the lowest genetic diversity was found in South Africa and Australia (A = 2·78–3·74; H = 0·49–0·57). Samples from California, Australia and South Africa, which had lower genetic diversity than those of Europe, were also characterized by demographic disequilibrium and, thus, may represent founding populations of the pathogen. Low but significant levels of genetic differentiation among all samples (DEST = 0·12, P = 0·001; FST = 0·03, P = 0·001) are consistent with historical gene flow preventing differentiation at continental scales. These findings suggest that global, human-mediated spread of the fungus may have resulted in its current global distribution.R. Travadon, K. Baumgartner, P. E. Rolshausen, W. D. Gubler, M. R. Sosnowski, P. Lecomte, F. Halleen and J.-P. Pero
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Efficacy of fungicides on mycelial growth of diatrypaceous fungi associated with grapevine trunk disease
'Springer Science and Business Media LLC', 2012Co-Authors: Gramaje D., Ayres M., Trouillas F., Sosnowski M.Abstract:Several species of Diatrypaceae have been recently isolated from the wood of cankered grapevines in several regions of the world and shown to be pathogenic with varying degrees of virulence when inoculated in stems of potted vines. Existing management strategies have focussed on the development of procedures and products to prevent or reduce Eutypa lata infection. The best method to prevent infection is by applying fungicides to wounds, but there are few registered chemicals for any of the diatrypaceous fungi in Australia. Six selected fungicides were evaluated in vitro for their efficacy in reducing mycelial growth of Eutypa lata, Cryptovalsa ampelina, Diatrypella vulgaris, Eutypa leptoplaca, Eutypella citricola and Eutypella microtheca. Carbendazim, fluazinam, tebuconazole, and prothioconazole + tebuconazole were effective at inhibiting mycelial growth of all Diatrypaceae spp. tested. Pyraclostrobin reduced colony diameter of most of the fungal species by 50% or more. Pyrimethanil was ineffective at reducing mycelial growth of these pathogens. Five of the six fungicides evaluated in this study have shown efficacy in vitro against Diatrypaceae spp. and require further evaluation in the field. This study represents the first approach for fungicide evaluation against mycelial growth of diatrypaceous fungi, other than Ea. lata. It contributes to the development of integrated management strategies for grapevine trunk diseases.Several species of Diatrypaceae have been recently isolated from the wood of cankered grapevines in several regions of the world and shown to be pathogenic with varying degrees of virulence when inoculated in stems of potted vines. Existing management strategies have focussed on the development of procedures and products to prevent or reduce Eutypa lata infection. The best method to prevent inDavid Gramaje & Matthew R. Ayres & Florent P. Trouillas & Mark R. Sosnowsk
Philippe E Rolshausen - One of the best experts on this subject based on the ideXlab platform.
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A method to detect and quantify Eutypa lata and Diplodia seriata-complex DNA in grapevine pruning wounds
Plant Disease, 2017Co-Authors: Jerome Pouzoulet, Daniel P. Lawrence, Renaud Travadon, Kendra Baumgartner, Philippe E Rolshausen, Marco Schiavon, Sebastiaan Bol, Vanessa E. Ashworth, Gwenaelle Comont, Marie-france Corio-costetAbstract:Trunk diseases are factors that limit sustainability of vineyards worldwide. Botryosphaeria and Eutypa diebacks are caused by several fungi belonging to the Botryosphaeriaceae and Diatrypaceae, respectively, with Diplodia seriata and Eutypa lata being two of the most common species. Previous information indicated that the traditional isolation method used to detect these pathogens from plant samples could underestimate their incidence levels. In the present study, we designed two sets of primers that target the β-tubulin gene and that are amenable for quantitative real-time PCR (qPCR) Sybr-Green assays for the detection and quantification of D. seriata-complex (DseCQF/R) and E. lata (ElQF/R) DNA. The design of a species-specific assay was achieved for E. lata. For D. seriata, a species-specific assay could not be designed. The low interspecific diversity across β-tubulin genes resulted in an assay that could not discriminate D. seriata from some closely related species either not yet reported or presenting a low prevalence on grapevine, such as D. intermedia. We validated our technique on grapevine spur samples naturally and artificially infected with D. seriata and E. lata during the dormant season. Experimental grapevines were located in two counties of northern California where the incidence of both pathogens was previously reported. The qPCR assays revealed that a high frequency of pruning wound infections (65%) was achieved naturally by E. lata, while low infection frequency (less than 5%) was observed using the reisolation method. For D. seriata-complex, low (5%) to no natural infection frequencies were observed by the qPCR and the reisolation method, respectively. These results also provided evidence that our qPCR detection methods were more sensitive to assess the incidence of E. lata and D. seriata-complex in plant samples, than traditional isolation techniques. Benefits of molecular methods for the detection of canker pathogens in the field under natural conditions are discussed.
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draft genome sequence of the grapevine dieback fungus Eutypa lata ucr el1
Genome Announcements, 2013Co-Authors: Barbara Blancoulate, Philippe E Rolshausen, Dario CantuAbstract:The vascular pathogen Eutypa lata, which causes Eutypa dieback in grapevines, is a major threat to grape production worldwide. Here, we present the first draft genome sequence of E. lata (UCR-EL1). The computational prediction and annotation of the protein-coding genes of UCR-EL1 provide an initial inventory of its potential virulence factors.
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use of boron for the control of Eutypa dieback of grapevines
Plant Disease, 2005Co-Authors: Philippe E Rolshausen, W D GublerAbstract:ABSTRACT Eutypa dieback is a perennial canker disease of grapevine (Vitis vinifera) caused by Eutypa lata. The fungus produces ascospores, which infect grapevines through pruning wounds during the dormant season. Management of the disease has been achieved with fungicide applications during the dormant period. However, no effective fungicide was available for this purpose after Benlate was withdrawn from the market. Boric acid (17.5% a.i. boron), a potential alternative to Benlate, was tested in the present study against E. lata. The EC50 values for inhibition of mycelial growth and ascospore germination were 125 and 475 μg of boric acid per ml (22 and 83 μg a.i./ml), respectively. Two boron-based treatments were developed and tested in vitro and in four field trials during 2001 to 2003. One product, biopaste, contained 5% boric acid (8.75 mg a.i./ml) in a commercial paste. The second product, bioshield, contained 5% boric acid in a spore suspension of Cladosporium herbarum. Both products significantly re...
