Letteratura scientifica selezionata sul tema "Botrytis cinerea"
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Articoli di riviste sul tema "Botrytis cinerea"
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Chen, Tong, Zhanquan Zhang, Yong Chen, Boqiang Li e Shiping Tian. "Botrytis cinerea". Current Biology 33, n. 11 (giugno 2023): R460—R462. http://dx.doi.org/10.1016/j.cub.2023.01.058.
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Chetelat, R. T., e L. Stamova. "TOLERANCE TO BOTRYTIS CINEREA". Acta Horticulturae, n. 487 (marzo 1999): 313–16. http://dx.doi.org/10.17660/actahortic.1999.487.48.
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Adjebli, Ahmed, Abdelaziz Messis, Riad Ayeche e Kamel Aissat. "Phenotypic variability of Botrytis cinerea and Botrytis pseudocinerea isolates". Research Journal of Biotechnology 17, n. 3 (25 febbraio 2022): 20–26. http://dx.doi.org/10.25303/1703rjbt2026.
Testo completoAbstract (sommario):
In the present study, eight single-spore strains of Botrytis cinerea were isolated from tomato greenhouses located in Bejaia regions (Northern Algeria). Isolates were molecularly characterized by nine microsatellite markers. Isolates were assigned to B. cinerea and B. pseudocinerea with four isolates of each species. Morphological characterization was established using two cultures media Potato Dextrose Agar and Malt Extract Agar. All isolates inoculated on PDA medium were exclusively Sclerotial and Mycelial on MEA medium. Aggressiveness of both species was similar on tomato leaves and apple fruits. Moreover, B. cinerea isolates were more aggressive than B. pseudocinerea on lettuce leaves. Tomato and lettuce leaves were significantly more susceptible to the both fungi. A negative correlation was established between aggressiveness and morphological type. Phenotypic variability is considered of major importance to explain the epidemiology of the two cryptic species.
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Vinogradova, Svetlana, Elena Porotikova, Emiliya Navrotskaya, Zsuzsanna Nagyne Galbacs, Sébastien Massart e Eva Varallyay. "The First Virome of a Russian Vineyard". Plants 12, n. 18 (18 settembre 2023): 3292. http://dx.doi.org/10.3390/plants12183292.
Testo completoAbstract (sommario):
Among other pathogens, more than 80 viruses infect grapevine. The aim of this work was to study the virome diversity of grapevine viruses and mycoviruses of a vineyard using high-throughput sequencing technologies. The grapevine virome was studied in symptomatic vines of the Rkatsiteli cultivar (V. vinifera) collected at the vineyards of the Krasnodar Krai in Russia. Ribosomal-depleted total RNA and isolated small RNAs were used for library preparation and high-throughput sequencing. Six grapevine-infecting viruses and two viroids were validated by RT-PCR and analyzed phylogenetically. We identified the presence of grapevine leafroll-associated virus 3, grapevine Pinot gris virus, grapevine virus T, grapevine rupestris stem-pitting-associated virus, grapevine fleck virus, and grapevine rupestris vein feathering virus, as well as two viroids, grapevine yellow speckle viroid 1 and hop stunt viroid. We also studied the mycovirome of the vineyard and identified nine viruses with single-stranded positive-sense RNA genomes: alternaria arborescens mitovirus 1, botrytis cinerea mitovirus 1, botrytis cinerea mitovirus 2, botrytis cinerea mitovirus 3, botrytis cinerea mitovirus 4, sclerotinia sclerotiorum mitovirus 3, botrytis cinerea hypovirus 1, grapevine-associated narnavirus 1, and botrytis virus F. In addition, we identified botrytis cinerea hypovirus 1 satellite-like RNA and two single-stranded negative-sense RNA viruses. This is the first study of grapevine mycoviruses in Russia. The obtained result will contribute to the development of biocontrol strategies in the future.
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Guetsky, Ruth, D. Shtienberg, Y. Elad, E. Fischer e A. Dinoor. "Improving Biological Control by Combining Biocontrol Agents Each with Several Mechanisms of Disease Suppression". Phytopathology® 92, n. 9 (settembre 2002): 976–85. http://dx.doi.org/10.1094/phyto.2002.92.9.976.
Testo completoAbstract (sommario):
Two biocontrol agents, a yeast (Pichia guilermondii) and a bacterium (Bacillus mycoides), were tested separately and together for suppression of Botrytis cinerea on strawberry leaves and plants. Scanning electron microscopy revealed significant inhibition of Botrytis cinerea conidial germination in the presence of Pichia guilermondii, whereas Bacillus mycoides caused breakage and destruction of conidia. When both biocontrol agents were applied in a mixture, conidial destruction was more severe. The modes of action of each of the biocontrol agents were elucidated and the relative quantitative contribution of each mechanism to suppression of Botrytis cinerea was estimated using multiple regression with dummy variables. The improvement in control efficacy achieved by introducing one or more mechanisms at a time was calculated. Pichia guilermondii competed with Botrytis cinerea for glucose, sucrose, adenine, histidine, and folic acid. Viability of the yeast cells played a crucial role in suppression of Botrytis cinerea and they secreted an inhibitory compound that had an acropetal effect and was not volatile. Bacillus mycoides did not compete for any of the sugars, amino acids, or vitamins examined at a level that would affect Botrytis cinerea development. Viable cells and the compounds secreted by them contributed similarly to Botrytis cinerea suppression. The bacteria secreted volatile and non-volatile inhibitory compounds and activated the defense systems of the host. The nonvolatile compounds had both acropetal and basipetal effects. Mixture of Pichia guilermondii and Bacillus mycoides resulted in additive activity compared with their separate application. The combined activity was due to the summation of biocontrol mechanisms of both agents. This work provides a theoretical explanation for our previous findings of reduced disease control variability with a mixture of Pichia guilermondii and Bacillus mycoides.
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Qiu, Lu, Hai Han Yang, Fang Lei, Shu Guo Fan, Mei Hua Xie e Zhen Ji Wang. "Studies on the Bacteriostasis of Nano-Silver on the Pathogenic Fungus Botrytis cinerea from Illed Plants". Applied Mechanics and Materials 651-653 (settembre 2014): 352–61. http://dx.doi.org/10.4028/www.scientific.net/amm.651-653.352.
Testo completoAbstract (sommario):
Obiective is studing the bacteriostasis of nanosilver on the pathogenic fungus Botryticinerea from illed plants. Five strains of Botrytis cinerea were used as the experimental materials. 0.3 % carbendazim and 0.3 % chlorothalonil were used as comparing chemistry bacteriostatic agents. The inhibitionand effects of bacteriostatic agents on the growth of mycelia, spore’s germination, size of the inhibitory zone, electrical conductivity, morphology and structure of Botrytis cinerea were studied. Results is that the bacteriostatic effects of nanosilver is significantly better than blank comparing experiment, and there are differentiation in strains. The bacteriostasis effece of carbendazim is better than chlorothalonil. The chlorothalonil is better than nanosilver. Conclusion is that There is better bacteriostasis against Botrytis cinerea for nanosilver. The The principle of bacteriostasis is that nanosilver disrupts permeation of cell mombrance of Botrytis cinerea.
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Ahmed, AU, S. Zaman, MA Mazid, MM Rahman, MMR Sarkar, L. Arbia, MM Ud-deen e G. Kabir. "Studies of Botrytis cinerea causing botrytis gray mold disease in chickpea (Cicer arietinum L.)". Journal of Bio-Science 22 (21 ottobre 2016): 69–76. http://dx.doi.org/10.3329/jbs.v22i0.30011.
Testo completoAbstract (sommario):
Context: To investigate the morphological and pathological information on causal organism Botrytis cinerea for better understanding of the infection process and controlling outbreaks of the most damaging disease, Botrytis Gray Mold (BGM),of chickpea.Objectives: To study the cultural and morphological characteristics and growth requirements of Botrytis cinerea Pers. ex. Fr. This study was also aimed to know about the cytological and genetic behavior of B. cinerea in relation to its pathogenicity and the infection process on chickpea.Materials and Methods: A total of 83 isolates of Botrytis cinerea Pers. ex. Fr. collected from the major chickpea growing areas of Bangladesh were studied under 5 and 2 different groups based on their cultural and morphological characteristics, respectively. Four different types of isolates were observed and characterized considering the arrangement of sclerotia by growing them on PDA. Cultural characteristics such as colony color, shape, margin and texture of B. cinerea isolates were observed on the prepared PDA medium. Morphological characteristics in terms of sclerotia color, shape and size, ability of sclerotia production and their arrangement were observed on PDA medium after three days of incubation at 20°C. The prepared samples were placed in a platinum coater providing 10 mA current flow and then placed into the Scanning Electron Microscope (SEM) for obtaining the image. The conidial observation was taken using aqua suspension under the fluorescence microscope at 19V/100W. SEM observation was made to study the infection process of B. cinerea. Data on quantitative and qualitative cultural characteristics were put into analytical software 'SPSS 11.5 for Windows' and nonhierarchical clustering was performed.Results: The mean sizes of five isolates of B. cinerea were 8.02-12.3x 5.1-9.0 ?m (volume 158.12-445.38 ?m3). The pathogen B. cinerea grew well on malt-extract agar (MEA) and chickpea dextrose agar (CDA) medium. The highest (81.26 mm) average mycelial radial growth was obtained on MEA followed by CDA (81.11 mm). Maximum disease in the shortest incubation period was produced with the inoculum concentration of 2.5×104. More pathogenicity and higher disease score was performed by the isolates containing higher mean number of nucleus per conidia than the isolates containing lower values. Optimum temperature and incubation time for conidial germination was observed at 20°C and 24 h, respectively. More than 90% relative humidity was needed for the germination of B. cinerea conidia. B. cinerea survived in all plant parts up to next cropping season. Sclerotia of B. cinerea were also found to survive in the soil up to 9 months. All the 5 isolates of B. cinerea remained viable after 3 years of storage in sterile water at -80°C and in sand at 4°C with same pathogenicity.Conclusion: The cyto-pathological observations including cultural and morphological information of the causal pathogen B. cinerea might be useful in controlling the outbreaks of the disease BGM and ultimately reducing the yield loss of the valuable crop chickpea.J. bio-sci. 22: 69-76, 2014
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Guerrero Prieto, Víctor Manuel, Juan Luis Jacobo Cuéllar, Rafael Ángel Parra Quezada, Marcos Iván Linares Marrufo, Damaris Leopoldina Ojeda Barrios, Ofelia Adriana Hernández Rodríguez, Loreto Robles Hernández, David Ignacio Berlanga Reyes e Iván Javier Cabanillas Mata. "Botrytis cinerea Pers. in postharvest apple fruit, control with Candida oleophila Montrocher strains and/or synthetic fungicides". Nova Scientia 11, n. 22 (29 maggio 2019): 69–84. http://dx.doi.org/10.21640/ns.v11i22.1645.
Testo completoAbstract (sommario):
As an alternative control method, to improve control and to reduce synthetic fungicide use, three Candida oleophila strains and/or four commercial synthetic fungicides were used to control Botrytis cinerea damage on postharvest apple fruit. Synthetic commercial fungicides; Cyprodinil+Fludioxonil, Thiabendazole and Benomyl, allowed Candida oleophila strains colony growth when challenged to the pressure of these fungicides. Synthetic commercial fungicide Captan did not allow any Candida oleophila strains colony growth. Control of Botrytis cinerea expressed in % of damage and damage reduction, gave an average control of; 100% for Cyprodinil+Fludioxonil; Captan, 97.5%; Thiabendazole, 94.1% and Benomyl, 93.7% All Candida oleophila strains, individually, gave a 100% control. Thiabendazole and Benomyl improved their efficiency to control Botrytis cinerea when combined with Candida oleophila. Control of Botrytis cinerea damage on postharvest Golden Delicious apple fruit can be achieved up to 100% either with Candida oleophila strains individually and/or with Cyprodinil+Fludioxonil alone. The use of Candida oleophila as an alternative method to control Botrytis cinerea damage on postharvest apple fruit means a reduction of synthetic fungicide use, plus avoiding fungicide residues on the treated apple fruit and on the environment, thus reducing the risk for human health damage.
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Komalaningrat, Devi ayu, Efi Toding Tondok e Widodo Widodo. "Identitas Spesies Botrytis pada Tanaman Hortikultura Di Jawa Barat, Indonesia". Jurnal Fitopatologi Indonesia 14, n. 6 (27 febbraio 2019): 205. http://dx.doi.org/10.14692/jfi.14.6.205.
Testo completoAbstract (sommario):
Identity of Botrytis Species on Horticultural Crops In West Java, IndonesiaBotrytis species are economically important pathogens with a very broad host range including more than 200 horticultural crops. The identity of these fungus found in Indonesia has not been investigated and need to be reconfirmed due to the species variations of Botrytis found worldwide. The aims of this research were to identify Botrytis species infecting crops in West Java based on its morphology and molecular characteristics, as well as its pathogenicity traits. Based on morphological characters, all 25 isolates found were identified as B. cinerea. ITS-based sequences of the 8 isolates showed 96-100% similarity to reported B. cinerea in GenBank. The phylogenetic analysis confirmed that all collected B. cinerea were grouped in the same cluster with Australia, Netherlands, and other Asian region isolates. Pathogenicity tests using strawberry fruits demonstrated that all isolates were pathogenic as indicated by grey mold symptom development; the isolates from orchid showed the highest virulence. This research is the first report confirming Botrytis cinerea identity based on morphology and molecular methods in Indonesia, and also confirmed B. cinerea as the only species of Botrytis found in West Java.
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Ripardo-Filho, Haroldo da Silva, Víctor Coca Ruíz, Ivonne Suárez, Javier Moraga, Josefina Aleu e Isidro G. Collado. "From Genes to Molecules, Secondary Metabolism in Botrytis cinerea: New Insights into Anamorphic and Teleomorphic Stages". Plants 12, n. 3 (26 gennaio 2023): 553. http://dx.doi.org/10.3390/plants12030553.
Testo completoAbstract (sommario):
The ascomycete Botrytis cinerea Pers. Fr., classified within the family Sclerotiniaceae, is the agent that causes grey mould disease which infects at least 1400 plant species, including crops of economic importance such as grapes and strawberries. The life cycle of B. cinerea consists of two phases: asexual (anamorph, Botrytis cinerea Pers. Fr.) and sexual (teleomorph, Botryotinia fuckeliana (de Bary) Wetzel). During the XVI International Symposium dedicated to the Botrytis fungus, which was held in Bari in June 2013, the scientific community unanimously decided to assign the most widely used name of the asexual form, Botrytis, to this genus of fungi. However, in the literature, we continue to find articles referring to both morphic stages. In this review, we take stock of the genes and metabolites reported for both morphic forms of B. cinerea between January 2015 and October 2022.
Tesi sul tema "Botrytis cinerea"
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Shafia, Aminath. "Latent infection of Botrytis cinerea". Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499372.
Testo completoAbstract (sommario):
Latent B. cinerea was detected in nine symptomless wild host species from the families Asteraceae and Brassicaceae, in addition to greenhouse grown lettuce. Conventional testing methods revealed that latent B. cinerea was equally prevalent in the root system as the above ground parts. Incidence of latent infection was moderate in some species (Achillea milleforlium, Arabidopsis thaliana, Centraurea nigra, Cirsium vulgare, Senecio jacobaea, Senecio vulgaris and Taraaxacum agg.) and rare in others (Tussilago farfara and Bellis perennis). In greenhouse lettuce, latent infection was activated by prolonged water stress and artificial inoculation. Despite inoculation, unstressed, vigorously growing lettuce and Arabidopsis plants remained asymptomatic throughout the growing period. Fungicide seed treatment did not significantly affect the amount of latent B. cinerea recovered from the lettuce plants. Introduction of antagonistic micro-organism Trichoderma harzianum T-39 into the soil decreased the amount of latent infection recovered from lettuce leaves but increased it in the stem. A weak negative correlation was found between photosynthesis and the amount of B. cinerea recovered from the leaves. Weight of the plants was reduced due to inoculation of B. cinerea even though latent infection was unaltered. There was no relation between plant weight and total endophytic B. cinerea. A marginal increase of the phenolic contents of the leaf was observed due to inoculation, but no changes to the antioxidant activity, chlorophyll content or carotenoids were found. The high incidence of latent infection found in greenhouse grown lettuce plants with or without successful inoculation may have been due to the presence of several genetically distinct isolates of B. cinerea. Eight different haplotypes were identified among the 32 isolates assessed. A single very common haplotype presumably originated from seed borne infection, because it was rare in plants grown from fungicide treated seed. Latency may be attributed to a mild strain defence response by the presence of several genetically different strains of the pathogen present within the plant as endophytes.
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Lewis, Megan. "The flavohaemoglobins of Botrytis cinerea". Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521869.
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Rajaguru, Bulathsinhalage Anuja Priyangani. "Molecular ecology of Botrytis cinerea". Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494963.
Testo completoAbstract (sommario):
Systemic Botrytis cinerea isolates were collected from non symptomatic fruits of Rubus fruticosus (blackberry) and Fragaria x ananassae (strawberry) and from roots and leaves of wild Primula vulgaris (primrose) and Taraxacum agg. (dandelion) in Brighton, Bath, and Reading separated by 80km or more. Isolates recovered from a Primula x polyantha crop at Reading were also tested. Approximately 300 isolates were genetically characterised using 9 published microsatellite primers and the presence of two transposable elements, boty and flipper. In wild primula and dandelion, incidence of non-symptomatic infection was very variable both geographically and between years. Isolates were usually haploid at all loci, with most haplotypes unique and no detectable linkage disequilibrium between loci.
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Emmanuel, C. J. "'Symptomless' infection by Botrytis cinerea". Thesis, University of Reading, 2016. http://centaur.reading.ac.uk/63176/.
Testo completoAbstract (sommario):
The study was carried out to clarify the nature of symptomless infection by Botrytis cinerea and to what extent it differs from aggressive necrotic infection in Lactuca sativa (lettuce) and Arabidopsis thaliana. Symptomless plants were produced by dry spore inoculation in plants growing in controlled environmental conditions or in glasshouses. Plating out of surface-disinfected and non-surface-disinfected samples of inoculated, apparently healthy, plants on selective medium revealed that the fungus was spreading from the initial inoculation site to newly developing plant organs both internally and externally. Similar findings were obtained in microscope experiments in which host plants were inoculated with GFP labelled B. cinerea and symptomless spreading was monitored under confocal laser scanning microscope. Spore germination on leaf surface was followed by development of sub-cuticular vesicles and plant cell damage in the infected epidermal cell and a few nearby cells. Sparsely branched long hyphae arose from the vesicles and spread on the leaf surface; spread was mostly on the outer surface of the epidermal layer but occasionally below the cuticle or epidermal cells. In the late symptomless phase, mycelium arising from single vesicles formed several mycelial networks on leaves. Experiments were carried out to compare the extent of gene expression in symptomless and necrotic infections, using RT-qPCR. Expression of selected genes was quantified in tissue samples based on the amount of mRNA of the respective genes found. In both host species, the mRNA concentration of signalling genes bcg1, bmp1 and calcineurin, and the pathogenicity genes bcsod1 and bcpg1 were similar to or slightly greater in symptomless samples than in necrotic samples. The mRNA of the signalling gene bac and pathogenicity genes bcbot1 and bcnep1, were not detected or detected in lower abundance than in necrosis. In lettuce, the leaves developing distant from the site of inoculation showed similar results to A. thaliana, but in healthy leaves close to the site of inoculation mRNA concentrations of bac and bcnep1 were similar to necrotic samples. Thus, in both host species, the fungus grew along with the plant and moved to newly growing plant parts without producing symptoms; during this growth some pathogenicity genes were less expressed than in necrotic infection.
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Biosa, Carlotta. "Botrytis cinerea e la sua forma nobile". Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
Cerca il testo completoAbstract (sommario):
Il presente elaborato descrive gli aspetti generali di Botrytis cinerea quando si sviluppa come muffa grigia e muffa nobile. La differenza fra queste due diverse forme non è data da una differenza genetica del fungo ma dal microclima presente nell'area di infezione. Infatti l'alternanza di condizioni umide a condizioni secche fa si che il fungo si sviluppi solo all'interno dello strato epidermico (acino infavato) senza sviluppare efflorescenze all'esterno dell'acino (muffa grigia).La presenza della muffa apporta all'acino una maggiore concentrazione di solidi solubili, un lieve innalzamento di pH e un aumento di componenti aromatiche. Queste caratteristiche diventano indispensabili per la produzione di vini bianchi dolci come Sauternes e Tokaj. La comparsa di muffa nobile avviene naturalmente in pochissime aree al mondo. questo perché i fattori di sviluppo sono molto limitanti. L'eccesso e la carenza di umidità o di caldo potrebbero compromettere lo sviluppo della muffa nobile. Questo fa pensare che il riscaldamento globale, comportando un innalzamento della temperatura e una diminuzione delle precipitazioni, possa ostacolare lo sviluppo di muffa nobile nelle uniche zone che presentano questa particolarità.
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Swadling, Iain. "Biological control of Botrytis cinerea in strawberries". Thesis, University of Kent, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240120.
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Deligeorgopoulou, Athina. "Sesquiterpenoids and their biotransformation by Botrytis cinerea". Thesis, University of Sussex, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392802.
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Bratt, Richard P. "Spoilage of senescing flax by Botrytis cinerea Pers". Thesis, Queen's University Belfast, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317056.
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Fernandez, Olivier. "Métabolisme du tréhalose chez la vigne (Vitis vinifera L.) en conditions stressantes : effets du froid et de l’infection par Botrytis cinerea". Thesis, Reims, 2011. http://www.theses.fr/2011REIMS016/document.
Testo completoAbstract (sommario):
L’objectif de mes travaux de thèse était d’étudier le métabolisme du tréhalose chez la vigne (Vitis vinifera L. cv. Chardonnay) en réponse à l’exposition à deux stress : le froid" chilling " et l’infection par le champignon pathogène Botrytis cinerea.Pour cela, nous avons tout d’abord optimisé un dosage du tréhalose par fluorimétrie qui nous a permis de caractériser le métabolisme du tréhalose en réponse à ces deux stress.Le métabolisme du tréhalose est activé différemment par le froid dans les organes dela vigne. Les gènes VvTPPA, codant une enzyme de synthèse du tréhalose, et VvTRE, codantla tréhalase, l’enzyme de dégradation, sont respectivement induits et réprimés dans les feuilleset leur expression est corrélée à une augmentation de la concentration en tréhalose. En outre,aucune synthèse de tréhalose n’est mesurée dans les tiges et il n’est pas détectable dans les racines. Enfin, la synthèse de T6P, son précurseur, est précoce dans les feuilles (3 heures aprèsl’exposition au froid). Nos résultats s’accordent avec le modèle actuel faisant du T6P une molécule-signal, corrélée à la concentration en saccharose. Ils excluent, pour le tréhalose, une participation significative à l’osmorégulation en réponse au froid chez la vigne. Par ailleurs,nous avons utilisé des plants de vigne bactérisés par Burkholderia phytofirmans, une bactérie endophyte induisant une tolérance au froid chez cette plante. Nous y avons observé une synthèse de T6P et de tréhalose et nous pensons que cette synthèse pourrait constituer une composante importante de la tolérance induite au froid.Lors de l’infection de feuilles de vitroplants de vigne par B. cinerea, nous avons observé (i) une forte augmentation de la quantité de tréhalose, (ii) l’induction de l’expression du gène VvTRE et (iii) l’augmentation de l’activité tréhalase. En revanche, aucune augmentation de la concentration en T6P n’a été détectée. Nous pensons donc que la synthèsede tréhalose in planta n’est pas favorisée durant l’infection et que le tréhalose détecté est probablement d’origine fongique. Nos résultats sont compatibles avec l’hypothèse selon laquelle l’induction du gène codant la tréhalase et l’augmentation concomitante de son activité interviendraient lors des interactions plantes-agents pathogènes pour éviter toute perturbation du rôle de molécule-signal joué par le T6P.Au final, le métabolisme du tréhalose participe à la réponse aux stress environnementaux chez la vigne et son étude mériterait d’être approfondie, notamment en ce qui concerne les stress biotiquesThe purpose of the present thesis was to investigate grapevine trehalose metabolism upon exposure to 2 stress conditions: chilling and infection by the grey mould fungus Botrytis cinerea.Initially, we had to optimize a fluorimetric based assay to assess trehalose concentration in grapevine. Latter, this method was used to characterize trehalose synthesis in this plant when exposed to chilling or infected by B. cinerea.Upon chilling exposure, trehalose metabolism is differentially activated in grapevine organs. VvTPPA, a gene involved in trehalose synthesis, and VvTRE, encoding the trehalose degrading enzyme (trehalase), were respectively induced and repressed and their expression was correlated with an increase of trehalose concentration in leaves. No trehalose synthesis was observed in stems and the sugar was undetectable in roots. T6P (its precursor)concentration increase was faster in leaves (3 hours after chilling exposure). Our results are in agreement with current status of T6P acting as a signal molecule, correlated with sucrose concentration, and exclude any significant participation of trehalose as a global osmoprotectant under chilling stress in grapevine. Additionally, we have used grapevine plants bacterized by Burkholderia phytofirmans, an endophytic bacterium that confers them chilling tolerance. We have detected T6P and trehalose synthesis in these plants and we believe it might contribute to the induced chilling tolerance.During grapevine leaf infection by B. cinerea, we observed: (i) a strong increase oftrehalose concentration, (ii) the induction of VvTRE and (iii) an increase of trehalase activity.However, no increase in T6P concentration was detected during infection. Our results suggest that trehalose metabolism is not activated upon B. cinerea infection and that trehalose detected is mainly of fungal origin. This is compatible with current hypothesis considering trehalase encoding gene induction and increase in trehalase activity as a plant response to avoid interference with T6P signaling pathway during pathogen infection.Overall, trehalose metabolism is involved in environmental stress responses in grapevine and might be consider for further research especially with focus on biotic stress
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Barnes, Sally Elissa. "The epidemiology of Botrytis cinerea on greenhouse grown ornamentals". Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394420.
Testo completoLibri sul tema "Botrytis cinerea"
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Variabilität und Pathogenität bei Botrytis cinerea. Berlin: J. Cramer, 1999.
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Johnson, Dennis A. Botrytis bunch rot of grape. Pullman, Wash: Cooperative Extension, College of Agriculture & Home Economics, Washington State University, 1986.
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Johnson, Dennis A. Botrytis neck rot of onion. Pullman, Wash: Cooperative Extension, College of Agriculture & Home Economics, Washington State University, 1986.
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Aljourmi, Ismail. Characterization and protein fingerprinting of Botrytis cinerea isolates. St. Catharines, Ont: Brock University, Dept. of Biological Sciences, 1999.
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James, Robert L. Resistance of Botrytis cinerea to vinclozolin, iprodione and dicloran. Missoula, Mont: USDA Forest Service, Northern Region, Cooperative Forestry and Pest Management, 1985.
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International Botrytis Symposium (10th 1992 Crete, Greece). Recent advances in Botrytis research: Proceedings of the 10th International Botrytis Symposium, Heraklion, Crete, Greece, 5-10 April 1992. A cura di Verhoeff K, Malathrakis N. E e Williamson B. Wageningen: Pudoc Scientific Publishers, 1992.
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Peterson, Michael James. Grey mould control by seedling canopy humidity reduction through under-bench ventiliation and styroblock aeration. Victoria, B.C: Forestry Canada, 1989.
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Peterson, Michael James. Grey mould control on container-grown Douglas-fir seedlings: Timing of fungicide application related to greenhouse environment. Victoria, B.C: Forestry Canada, 1988.
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Gligor, Bojkov. Gray Mold (Botrytis Cinerea) at Vines. Scientific Research Publishing, 2022.
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Gligor, Bojkov. Gray Mold (Botrytis Cinerea) at Vines. Scientific Research Publishing, 2022.
Cerca il testo completoCapitoli di libri sul tema "Botrytis cinerea"
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De Miccolis Angelini, Rita Milvia, Stefania Pollastro e Franco Faretra. "Genetics of Botrytis cinerea". In Botrytis – the Fungus, the Pathogen and its Management in Agricultural Systems, 35–53. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-23371-0_3.
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Claus, Harald. "Laccases of Botrytis cinerea". In Biology of Microorganisms on Grapes, in Must and in Wine, 339–56. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-60021-5_14.
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Tudzynski, Bettina, e Christian Schulze Gronover. "Signalling in Botrytis cinerea". In Botrytis: Biology, Pathology and Control, 85–97. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-2626-3_6.
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Marois, James J. "Biological Control of Botrytis Cinerea". In Biological Control of Plant Diseases, 109–11. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4757-9468-7_15.
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Vykoupil, Libor. "Botrys neboli esej o záludnostech historikovy práce (rozprava o metodě)". In Filosofie jako životní cesta, 182–91. Brno: Masaryk University Press, 2019. http://dx.doi.org/10.5817/cz.muni.p210-9458-2019-14.
Testo completoAbstract (sommario):
The elder and more experienced certainly know or at least have a vague idea that there used to be a Greek brandy named Botrys containing 40 % of alcohol. Its name was probably derived from the name of Botrytis cinerea (botrytis bunch rot, more commonly). The Greek term is Βότρυς and its transcription into Latin alphabet is Votrus or Votris. However, if a scholar attempts to verify in such an elementary finding, they can get entangled in very complex and tricky historical facts. After weeks of hard work it turned out that it is probably easier to write a chapter on the history of Greek economy of the second half of 19th century than a few lines on a distillery producing a brandy called Botrys. And so this contribution somehow by the way describes a solution to the „raisin problem“ in order to conclude with some basic information on the label Botrys.
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Dik, Aleid J., e Jos P. Wubben. "Epidemiology of Botrytis cinerea Diseases in Greenhouses". In Botrytis: Biology, Pathology and Control, 319–33. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-2626-3_17.
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Van Der Cruyssen, G., e O. Kamoen. "Regulation of Polygalacturonases of Botrytis Cinerea". In Developments in Plant Pathology, 80. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1737-1_16.
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Schumacher, Julia, e Paul Tudzynski. "Morphogenesis and Infection in Botrytis cinerea". In Topics in Current Genetics, 225–41. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-22916-9_11.
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Elmer, Philip A. G., e Themis J. Michailides. "Epidemiology of Botrytis cinerea in Orchard and Vine Crops". In Botrytis: Biology, Pathology and Control, 243–72. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-2626-3_14.
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Lyon, Gary D., Bernard A. Goodman e Brian Williamson. "Botrytis cinerea Perturbs Redox Processes as an Attack Strategy in Plants". In Botrytis: Biology, Pathology and Control, 119–41. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-2626-3_8.
Testo completoAtti di convegni sul tema "Botrytis cinerea"
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Saleh, Iman, e Mohammed Abu-Dieyeh. "Novel Prosopis Juliflora Leaf Ethanolic extract as natural Antifungal agent against Botrytis Cinerea: Application on Strawberries’ shelf-life extension". In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2021. http://dx.doi.org/10.29117/quarfe.2021.0044.
Testo completoAbstract (sommario):
Spoilage from fresh produces is a worldwide concern that accompanies the global increase in food demand. Adverse human health and environmental effects of commercial pesticides is a major public concern. Botrytis cinerea is one of the top ten pathogens that affect fresh produce including strawberries’ shelf-life around the world. Botrytis cinerea can progress easily from infected fruits to healthy ones even at low storage temperatures, which can lead to spoilage of entire lots in few weeks. Strawberries are widely consumed raw berries, which are famous in their processed forms such as jam and juices. The delicate fruit has a very short postharvest life. It is susceptible to mechanical injuries, fast dehydration and fungal infection. Prosopis juliflora is an invasive tree in many countries including Qatar. In this report, the Prosopis juliflora water soluble leaves ethanolic (PJ-WS-LE) novel extraction method will be described with an evaluation of its effectiveness as antifungal agent and possible coating material for shelf-life extension. PJ-WS-LE extract showed total inhibition of Botrytis cinerea growth with a minimum inhibitory concentration of 1mg/ml. Exposure to the extract affected badly the structure of the hyphal fungi. The extract extended also strawberries’ shelf-life by 2.32X. PJ-WS-LE extract will be chemically described and its effectiveness in the extension of other fresh produces’ shelf-life will be evaluated.
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Rodas, Alejandro, Julio César Chavarro Porras e Gloria Edith Guerrero Álvarez. "Modelo de recomendación para alerta temprana del hongo Botritys Cinerea en el cultivo de Mora de Castilla sin espinas (Rubus Glaucus Benth) en el departamento de Risaralda". In Nuevas realidades para la educación en ingeniería: currículo, tecnología, medio ambiente y desarrollo. Asociación Colombiana de Facultades de Ingeniería - ACOFI, 2022. http://dx.doi.org/10.26507/paper.2627.
Testo completoAbstract (sommario):
En la agricultura, el control de enfermedades se ha considerado como una tarea desafiante. Dentro de las especies que afectan el cultivo de Mora de Castilla se encuentra el hongo Botrytis cinerea, el cual puede generar pérdidas (entre el 50 y el 76 % del fruto cosechado). Generalmente, la opción empleada para combatirlo es a través de métodos químicos. Las tendencias actuales en la producción de alimentos están orientadas a obtener productos con menor carga de pesticidas, exigencias en conservación ambiental e inocuidad de los alimentos. Una ayuda para los agricultores es el desarrollo de herramientas que asistan en el proceso de toma de decisiones y en la predicción de enfermedades en el cultivo. Diversos modelos se han construido tendiendo como propósito describir el patosistema (patógeno/planta) que se estudia, donde cada uno presenta un enfoque distinto (empírico o analítico). No obstante, dichos modelos presentan sus pros y contras en términos de tiempo, esfuerzos e inversiones necesarias para su desarrollo, así como en términos de precisión y robustez. En tal panorama, los Sistemas de Recomendación (SR) son utilizados en la agricultura precisamente porque tienen como objetivo ayudar en la toma de decisiones donde al emplear algoritmos de aprendizaje de máquina permite hacer uso del historial de datos y realizar predicciones. Sin embargo, no se encontraron investigaciones publicadas que describan el patosistema Botrytis cinerea - Mora de Castilla en el campo de SR. Esto lleva a la pregunta de investigación: ¿Cómo predecir el surgimiento del hongo Botrytis cinerea en el cultivo de Mora de Castilla sin espinas (Rubus glaucus Benth) en Risaralda? En tal sentido, en la presente propuesta se propone un Modelo de Recomendación para Alerta Temprana del Hongo Botritys Cinerea en el Cultivo de Mora de Castilla sin Espinas (Rubus glaucus Benth) en el Departamento de Risaralda. La adquisición de datos se realizará en campo identificando las variables edáficas y climáticas relevantes en el cultivo de Mora de Castilla y que influyen en el brote de Botrytis cinerea. Posteriormente, se realiza la fase de procesamiento de datos, se utilizará un modelo de agrupamiento para encontrar similitudes (k-means) y se construye el modelo para el SR. Para la predicción del brote del hongo se utilizará la técnica de ensamble Bagging en los algoritmos Random Forest, KNN y Support Vector Machine. Las métricas de evaluación para el modelo serán Root Mean Square Error y Mean Absolute Error. Finalmente, se construye la alerta temprana, donde al existir un nivel igual o superior al 10 % se considera que existe afectación de B. Cinerea.
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Nijhawan, Rahul, Rahul Kumar Singh, Rajendra Singh Bisht, Neha Mendirtta, Pritish Dhir e Vaishnavi Singh. "Detection of Botrytis Cinerea in Grapes using Machine Learning Technique". In 2023 International Conference on Evolutionary Algorithms and Soft Computing Techniques (EASCT). IEEE, 2023. http://dx.doi.org/10.1109/easct59475.2023.10393855.
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Liu, Yutong, Justin Kuo, Kerik Cox, Justine Vanden Heuvel, Kirstin Petersen e Amit Lal. "Imaging and Detection of Botrytis Cinerea with Gigahertz Ultrasonic Imager". In 2021 IEEE International Ultrasonics Symposium (IUS). IEEE, 2021. http://dx.doi.org/10.1109/ius52206.2021.9593815.
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Jia, Li-yuan, e Xin-she Liu. "Effect of Six Fungicides against Botrytis Cinerea on Protected Cultivation Tomato". In 2011 Second International Conference on Digital Manufacturing and Automation (ICDMA). IEEE, 2011. http://dx.doi.org/10.1109/icdma.2011.124.
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Leandro Rodrigues, Rita Alaide, Enio Nazaré de Oliveira Junior e Thamara Carvalho Coutinho. "CONTROLE DO CRESCIMENTO DO FUNGO BOTRYTIS CINEREA EM MORANGOS UTILIZANDO QUITOSANA". In Simpósio Nacional de Bioprocessos e Simpósio de Hidrólise Enzimática de Biomassa. Campinas - SP, Brazil: Galoá, 2015. http://dx.doi.org/10.17648/sinaferm-2015-33436.
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Cardillo, Alejandra B., Stella M. Romero, Maria C. Martinez-Ceron, Silvia A. Camperi e Silvana L. Giudicessi. "New Antimicrobial Peptides as Potential Candidates in the Control Growth of Botrytis cinerea". In 36th European Peptide Symposium. The European Peptide Society, 2022. http://dx.doi.org/10.17952/36eps.2022.047.
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Sai Cheng e Xingfeng Shao. "In vivo antifungal activities of the tea tree oil vapor against Botrytis cinerea". In 2011 International Conference on New Technology of Agricultural Engineering (ICAE). IEEE, 2011. http://dx.doi.org/10.1109/icae.2011.5943945.
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Nobuhiro Aoyagi, Luciano, e Suely Mayumi Obara Doi. "Avaliação da Atividade Antagonista de Trichoderma harzianum sobre Fusarium oxysporum e Botrytis cinerea". In Simpósio de Bioquímica e Biotecnologia. Londrina - PR, Brazil: Galoa, 2017. http://dx.doi.org/10.17648/simbbtec-2017-80820.
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Cardillo, Alejandra B., Stella M. Romero, María C. Martínez-Ceron, Silvia A. Camperi e Silvana L. Giudicessi. "New Antimicrobial Peptides as Potential Candidates in the Control Growth of Botrytis cinerea". In 36th European Peptide Symposium. The European Peptide Society, 2022. http://dx.doi.org/10.17952/36eps/36eps.2022.047.
Testo completoRapporti di organizzazioni sul tema "Botrytis cinerea"
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Sharon, Amir, e Tesfaye Mengiste. Molecular dissection of host and pathogen factors in Botrytis cinerea pathogenesis for improved genetic resistance. United States Department of Agriculture, gennaio 2016. http://dx.doi.org/10.32747/2016.7604272.bard.
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Sharon, Amir, e Maor Bar-Peled. Identification of new glycan metabolic pathways in the fungal pathogen Botrytis cinerea and their role in fungus-plant interactions. United States Department of Agriculture, 2012. http://dx.doi.org/10.32747/2012.7597916.bard.
Testo completoAbstract (sommario):
The involvement of glycans in microbial adherence, recognition and signaling is often a critical determinant of pathogenesis. Although the major glycan components of fungal cell walls have been identified there is limited information available on its ‘minor sugar components’ and how these change during different stages of fungal development. Our aim was to define the role of Rhacontaining-glycans in the gray mold disease caused by the necrotrophic fungus B. cinerea. The research was built on the discovery of two genes, Bcdhand bcer, that are involved in formation of UDP-KDG and UDP-Rha, two UDP- sugars that may serve as donors for the synthesis of cell surface glycans. Objectives of the proposed research included: 1) To determine the function of B. cinereaBcDh and BcEr in glycan biosynthesis and in pathogenesis, 2) To determine the expression pattern of BcDH and BcERand cellular localization of their encoded proteins, 3) Characterize the structure and distribution of Rha- containing glycans, 4) Characterization of the UDP-sugar enzymes and potential of GTs involved in glycanrhamnosylation. To address these objectives we generated a series of B. cinereamutants with modifications in the bchdhand bcergenes and the phenotype and sugar metabolism in the resulting strains were characterized. Analysis of sugar metabolites showed that changes in the genes caused changes in primary and secondary sugars, including abolishment of rhamnose, however abolishment of rhamnose synthesis did not cause changes in the fungal phenotype. In contrast, we found that deletion of the second gene, bcer, leads to accumulation of the intermediate sugar – UDP- KDG, and that such mutants suffer from a range of defects including reduced virulence. Further analyses confirmed that UDP-KDG is toxic to the fungus. Studies on mode of action suggested that UDP-KDG might affect integrity of the fungal cell wall, possibly by inhibiting UDP-sugars metabolic enzymes. Our results confirm that bcdhand bcerrepresent a single pathway of rhamnose synthesis in B. cinerea, that rhamnose does not affect in vitro development or virulence of the fungus. We also concluded that UDP-KDG is toxic to B. cinereaand hence UDP-KDG or compounds that inhibit Er enzymes and lead to accumulation of UDP-KDG might have antifungal activity. This toxicity is likely the case with other fungi, this became apparent in a collaborative work with Prof. Bart Thomma of Wageningen University, NETHERLANDS . We have shown the deletion of ER mutant in Verticillium dahlia gave plants resistance to the fungal infection.
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Lichter, Amnon, Joseph L. Smilanick, Dennis A. Margosan e Susan Lurie. Ethanol for postharvest decay control of table grapes: application and mode of action. United States Department of Agriculture, luglio 2005. http://dx.doi.org/10.32747/2005.7587217.bard.
Testo completoAbstract (sommario):
Original objectives: Dipping of table grapes in ethanol was determined to be an effective measure to control postharvest gray mold infection caused by Botrytis cinerea. Our objectives were to study the effects of ethanol on B.cinerea and table grapes and to conduct research that will facilitate the implementation of this treatment. Background: Botrytis cinerea is known as the major pathogen of table grapes in cold storage. To date, the only commercial technology to control it relied on sulfur dioxide (SO₂) implemented by either fumigation of storage facilities or from slow release generator pads which are positioned directly over the fruits. This treatment is very effective but it has several drawbacks such as aftertaste, bleaching and hypersensitivity to humans which took it out of the GRAS list of compounds and warranted further seek for alternatives. Prior to this research ethanol was shown to control several pathogens in different commodities including table grapes and B. cinerea. Hence it seemed to be a simple and promising technology which could offer a true alternative for storage of table grapes. Further research was however required to answer some practical and theoretical questions which remained unanswered. Major conclusions, solutions, achievements: In this research project we have shown convincingly that 30% ethanol is sufficient to prevent germination of B. cinerea and kill the spores. In a comparative study it was shown that Alternaria alternata is also rather sensitive but Rhizopus stolonifer and Aspergillus niger are less sensitive to ethanol. Consequently, ethanol protected the grapes from decay but did not have a significant effect on occurrence of mycotoxigenic Aspergillus species which are present on the surface of the berry. B. cinerea responded to ethanol or heat treatments by inducing sporulation and transient expression of the heat shock protein HSP104. Similar responses were not detected in grape berries. It was also shown that application of ethanol to berries did not induce subsequent resistance and actually the berries were slightly more susceptible to infection. The heat dose required to kill the spores was determined and it was proven that a combination of heat and ethanol allowed reduction of both the ethanol and heat dose. Ethanol and heat did not reduce the amount or appearance of the wax layers which are an essential component of the external protection of the berry. The ethanol and acetaldehyde content increased after treatment and during storage but the content was much lower than the natural ethanol content in other fruits. The efficacy of ethanol applied before harvest was similar to that of the biological control agent, Metschnikowia fructicola, Finally, the performance of ethanol could be improved synergistically by packaging the bunches in modified atmosphere films which prevent the accumulation of free water. Implications, both scientific and agricultural: It was shown that the major mode of action of ethanol is mediated by its lethal effect on fungal inoculum. Because ethanol acts mainly on the cell membranes, it was possible to enhance its effect by lowering the concentration and elevating the temperature of the treatment. Another important development was the continuous protection of the treated bunches by modified atmosphere that can solve the problem of secondary or internal infection. From the practical standpoint, a variety of means were offered to enhance the effect of the treatment and to offer a viable alternative to SO2 which could be instantly adopted by the industry with a special benefit to growers of organic grapes.
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Reisch, Bruce, Avichai Perl, Julie Kikkert, Ruth Ben-Arie e Rachel Gollop. Use of Anti-Fungal Gene Synergisms for Improved Foliar and Fruit Disease Tolerance in Transgenic Grapes. United States Department of Agriculture, agosto 2002. http://dx.doi.org/10.32747/2002.7575292.bard.
Testo completoAbstract (sommario):
Original objectives . 1. Test anti-fungal gene products for activity against Uncinula necator, Aspergillus niger, Rhizopus stolonifer and Botrytis cinerea. 2. For Agrobacterium transformation, design appropriate vectors with gene combinations. 3. Use biolistic bombardment and Agrobacterium for transformation of important cultivars. 4. Characterize gene expression in transformants, as well as level of powdery mildew and Botrytis resistance in foliage of transformed plants. Background The production of new grape cultivars by conventional breeding is a complex and time-consuming process. Transferring individual traits via single genes into elite cultivars was proposed as a viable strategy, especially for vegetatively propagated crops such as grapevines. The availability of effective genetic transformation procedures, the existence of genes able to reduce pathogen stress, and improved in vitro culture methods for grapes, were combined to serve the objective of this proposal. Effective deployment of resistance genes would reduce production costs and increase crop quality, and several such genes and combinations were used in this project. Progress The efficacy of two-way combinations of Trichoderma endochitinase (CHIT42), synthetic peptide ESF12 and resveratrol upon the control of growth of Botrytis cinerea and Penicillium digitatum were evaluated in vitro. All pairwise interactions were additive but not synergistic. Per objective 2, suitable vectors with important gene combinations for Agrobacterium transformation were designed. In addition, multiple gene co-transformation by particle bombardment was also tested successfully. In New York, transformation work focused on cultivars Chardonnay and Merlot, while the technology in Israel was extended to 41B, R. 110, Prime, Italia, Gamay, Chardonnay and Velika. Transgenic plant production is summarized in the appendix. Among plants developed in Israel, endochitinase expression was assayed via the MuchT assay using material just 1-5 days after co-cultivation. Plants of cv. Sugraone carrying the gene coding for ESF12, a short anti-fungal lytic peptide under the control of the double 358 promoter, were produced. Leaf extracts of two plants showed inhibition zones that developed within 48 h indicating the inhibitory effect of the leaf extracts on the six species of bacteria. X fastidiosa, the causal organism of Pierce's disease, was very sensitive to leaf extracts from ESF12 transformed plants. Further work is needed to verify the agricultural utility of ESF12 transformants. In New York, some transformants were resistant to powdery mildew and Botrytis fruit rot. Major conclusions, solutions, achievements and implications The following scientific achievements resulted from this cooperative BARD project: 1. Development and improvement of embryogenesis and tissue culture manipulation in grape, while extending these procedures to several agriculturally important cultivars both in Israel and USA. 2. Development and improvement of novel transformation procedures while developing transformation techniques for grape and other recalcitrant species. 3. Production of transgenic grapevines, characterization of transformed vines while studying the expression patterns of a marker gene under the control of different promoter as the 35S CaMV in different part of the plants including flowers and fruits. 4. Expression of anti-fungal genes in grape: establishment of transgenic plants and evaluation of gene expression. Development of techniques to insert multiple genes. 5. Isolation of novel grape specific promoter to control the expression of future antimicrobial genes. It is of great importance to report that significant progress was made in not only the development of transgenic grapevines, but also in the evaluation of their potential for increased resistance to disease as compared with the non engineered cultivar. In several cases, increased disease resistance was observed. More research and development is still needed before a product can be commercialized, yet our project lays a framework for further investigations.
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Lichter, Amnon, Gopi K. Podila e Maria R. Davis. Identification of Genetic Determinants that Facilitate Development of B. cinerea at Low Temperature and its Postharvest Pathogenicity. United States Department of Agriculture, marzo 2011. http://dx.doi.org/10.32747/2011.7592641.bard.
Testo completoAbstract (sommario):
Botrytis cinerea is the postharvest pathogen of many agricultural produce with table grapes, strawberries and tomatoes as major targets. The high efficiency with which B. cinerea causes disease on these produce during storage is attributed in part due to its exceptional ability to develop at very low temperature. Our major goal was to understand the genetic determinants which enable it to develop at low temperature. The specific research objectives were: 1. Identify expression pattern of genes in a coldenriched cDNA library. 2. Identify B. cinerea orthologs of cold-induced genes 3. Profile protein expression and secretion at low temperature on strawberry and grape supplemented media. 4. Test novel methods for the functional analysis of coldresponsive genes. Objective 1 was modified during the research because a microarray platform became available and it allowed us to probe the whole set of candidate genes according to the sequence of 2 strains of the fungus, BO5.10 and T4. The results of this experiment allowed us to validate some of our earlier observations which referred to genes which were the product of a SSH suppression-subtraction library. Before the microarray became available during 2008 we also analyzed the expression of 15 orthologs of cold-induced genes and some of these results were also validated by the microarray experiment. One of our goals was also to perform functional analysis of cold-induced genes. This goal was hampered for 3 years because current methodology for transformation with ‘protoplasts’ failed to deliver knockouts of bacteriordopsin-like (bR) gene which was our primary target for functional analysis. Consequently, we developed 2 alternative transformation platforms, one which involves an air-gun based technique and another which involves DNA injection into sclerotia. Both techniques show great promise and have been validated using different constructs. This contribution is likely to serve the scientific community in the near future. Using these technologies we generated gene knockout constructs of 2 genes and have tested there effect on survival of the fungus at low temperature. With reference to the bR genes our results show that it has a significant effect on mycelial growth of the B. cinerea and the mutants have retarded development at extreme conditions of ionic stress, osmotic stress and low temperature. Another gene of unknown function, HP1 is still under analysis. An ortholog of the yeast cold-induced gene, CCH1 which encodes a calcium tunnel and was shown to be cold-induced in B. cinerea was recently cloned and used to complement yeast mutants and rescue them from cold-sensitivity. One of the significant findings of the microarray study involves a T2 ribonuclease which was validated to be cold-induced by qPCR analysis. This and other genes will serve for future studies. In the frame of the study we also screened a population of 631 natural B. cinerea isolates for development at low temperature and have identified several strains with much higher and lower capacity to develop at low temperature. These strains are likely to be used in the future as candidates for further functional analysis. The major conclusions from the above research point to specific targets of cold-induced genes which are likely to play a role in cold tolerance. One of the most significant observations from the microarray study is that low temperature does not induce ‘general stress response in B. cinerea, which is in agreement to its exceptional capacity to develop at low temperature. Due to the tragic murder of the Co-PI Maria R. Davis and GopiPodila on Feb. 2010 it is impossible to deliver their contribution to the research. The information of the PI is that they failed to deliver objective 4 and none of the information which relates to objective 3 has been delivered to the PI before the murder or in a visit to U. Alabama during June, 2010. Therefore, this report is based solely on the IS data.
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Chalutz, Edo, Michael Wisniewski, Samir Droby, Yael Eilam e Ilan Chet. Mode of Action of Yeast Biocontrol Agents of Postharvest Diseases of Fruits. United States Department of Agriculture, giugno 1996. http://dx.doi.org/10.32747/1996.7613025.bard.
Testo completoAbstract (sommario):
In a previous BARD-supported study, three of the investigators of this research were involved in a study on biological control of postharvest diseases of citrus and deciduous fruits. Several naturally occurring, non-antibiotic producing yeast antagonists were identified. Application of some of these antagonists resulted in very high levels of biocontrol under laboratory conditions but lower efficacy in semi-commercial tests. It was felt that the lack of knowledge on the mode of action of the biocontrol agents was limiting their efficient use. The current study was aimed at narrowing this gap in our knowledge. Two specific objectives were outlined: to study the mechanism by which calcium salts enhance biocontrol activity and to determine the role, if any, of the yeast extracellular materials and/or enzymes which degrade fungal cell walls during the interaction between the antagonists, the pathogen and the host. CaCl2 but not MgCl2, inhibited spore germination, and germ-tube elongation of Botrytis cinerea, Penicillium expansum and P. digitatum in culture. It also inhibited the pectinolytic activity of the pathogens. Biocontrol of apple decay by isolate 182 of Candida oleophila, an effective biocontrol agent, was enhanced by the addition of CaCl2 whereas there was no effect on the biocontrol activity of isolate 247 of this yeast. Similarly, CaCl2 enhanced efficacy of the US-7 isolate of Pichia guilliermondii in reducing infection of P. digitatum in citrus fruit. CaCl2 by itself also reduced the infection of peel wounds and stimulated ethylene production by grapefruit peel. This antagonist exhibited a very high ability to maintain cytosolic Ca2+ homeostasis when exposed to high CaCl2 concentrations. It is postulated, therefore, that enhanced biocontrol activity by calcium is the result of direct inhibition of the pathogen by calcium ions on spore germination and metabolism and indirectly due to the ability of the biocontrol agent to maintain normal metabolism in the presence of high levels of calcium. The extracellular materials produced by P. guilliermondii in culture and on the fruit inhibited, at low concentrations, the pathogen in culture and reduced percent infection of the fruit. The direct inhibition of the pathogen by these materials may thus be involved in the mode of action of the antagonist. This study contributed to our knowledge on the action of calcium salts and the yeast antagonist extracellular materials on biocontrol activity and will contribute to a more efficient use of this technology in the control of postharvest diseases of fruits.
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Granot, David, Richard Amasino e Avner Silber. Mutual effects of hexose phosphorylation enzymes and phosphorous on plant development. United States Department of Agriculture, gennaio 2006. http://dx.doi.org/10.32747/2006.7587223.bard.
Testo completoAbstract (sommario):
Research objectives 1) Analyze the combined effects of hexose phosphorylation and P level in tomato and Arabidopsis plants 2) Analyze the combined effects of hexose phosphorylation and P level in pho1 and pho2 Arabidopsis mutants 3) Clone and analyze the PHO2 gene 4) Select Arabidopsis mutants resistant to high and low P 5) Analyze the Arabidopsis mutants and clone the corresponding genes 6) Survey wild tomato species for growth characteristics at various P levels Background to the topic Hexose phosphorylating enzymes, the first enzymes of sugar metabolism, regulate key processes in plants such as photosynthesis, growth, senescence and vascular transport. We have previously discovered that hexose phosphorylating enzymes might regulate these processes as a function of phosphorous (P) concentration, and might accelerate acquisition of P, one of the most limiting nutrients in the soil. These discoveries have opened new avenues to gain fundamental knowledge about the relationship between P, sugar phosphorylation and plant development. Since both hexose phosphorylating enzymes and P levels affect plant development, their interaction is of major importance for agriculture. Due to the acceleration of senescence caused by the combined effects of hexose phosphorylation and P concentration, traits affecting P uptake may have been lost in the course of cultivation in which fertilization with relatively high P (30 mg/L) are commonly used. We therefore intended to survey wild tomato species for high P-acquisition at low P soil levels. Genetic resources with high P-acquisition will serve not only to generate a segregating population to map the trait and clone the gene, but will also provide a means to follow the trait in classical breeding programs. This approach could potentially be applicable for other crops as well. Major conclusions, solutions, achievements Our results confirm the mutual effect of hexose phosphorylating enzymes and P level on plant development. Two major aspects of this mutual effect arose. One is related to P toxicity in which HXK seems to play a major role, and the second is related to the effect of HXK on P concentration in the plant. Using tomato plants we demonstrated that high HXK activity increased leaf P concentration, and induced P toxicity when leaf P concentration increases above a certain high level. These results further support our prediction that the desired trait of high-P acquisition might have been lost in the course of cultivation and might exist in wild species. Indeed, in a survey of wild species we identified tomato species that acquired P and performed better at low P (in the irrigation water) compared to the cultivated Lycopersicon esculentum species. The connection between hexose phosphorylation and P toxicity has also been shown with the P sensitive species VerticordiaplumosaL . in which P toxicity is manifested by accelerated senescence (Silber et al., 2003). In a previous work we uncovered the phenomenon of sugar induced cell death (SICD) in yeast cells. Subsequently we showed that SICD is dependent on the rate of hexose phosphorylation as determined by Arabidopsis thaliana hexokinase. In this study we have shown that hexokinase dependent SICD has many characteristics of programmed cell death (PCD) (Granot et al., 2003). High hexokinase activity accelerates senescence (a PCD process) of tomato plants, which is further enhanced by high P. Hence, hexokinase mediated PCD might be a general phenomena. Botrytis cinerea is a non-specific, necrotrophic pathogen that attacks many plant species, including tomato. Senescing leaves are particularly susceptible to B. cinerea infection and delaying leaf senescence might reduce this susceptibility. It has been suggested that B. cinerea’s mode of action may be based on induction of precocious senescence. Using tomato plants developed in the course of the preceding BARD grant (IS 2894-97) and characterized throughout this research (Swartzberg et al., 2006), we have shown that B. cinerea indeed induces senescence and is inhibited by autoregulated production of cytokinin (Swartzberg et al., submitted). To further determine how hexokinase mediates sugar effects we have analyzed tomato plants that express Arabidopsis HXK1 (AtHXK1) grown at different P levels in the irrigation water. We found that Arabidopsis hexokinase mediates sugar signalling in tomato plants independently of hexose phosphate (Kandel-Kfir et al., submitted). To study which hexokinase is involved in sugar sensing we searched and identified two additional HXK genes in tomato plants (Kandel-Kfir et al., 2006). Tomato plants have two different hexose phosphorylating enzymes; hexokinases (HXKs) that can phosphorylate either glucose or fructose, and fructokinases (FRKs) that specifically phosphorylate fructose. To complete the search for genes encoding hexose phosphorylating enzymes we identified a forth fructokinase gene (FRK) (German et al., 2004). The intracellular localization of the four tomato HXK and four FRK enzymes has been determined using GFP fusion analysis in tobacco protoplasts (Kandel-Kfir et al., 2006; Hilla-Weissler et al., 2006). One of the HXK isozymes and one of the FRK isozymes are located within plastids. The other three HXK isozymes are associated with the mitochondria while the other three FRK isozymes are dispersed in the cytosol. We concluded that HXK and FRK are spatially separated in plant cytoplasm and accordingly might play different metabolic and perhaps signalling roles. We have started to analyze the role of the various HXK and FRK genes in plant development. So far we found that LeFRK2 is required for xylem development (German et al., 2003). Irrigation with different P levels had no effect on the phenotype of LeFRK2 antisense plants. In the course of this research we developed a rapid method for the analysis of zygosity in transgenic plants (German et al., 2003).
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Dickman, Martin B., e Oded Yarden. Modulation of the Redox Climate and Phosphatase Signaling in a Necrotroph: an Axis for Inter- and Intra-cellular Communication that Regulates Development and Pathogenicity. United States Department of Agriculture, agosto 2011. http://dx.doi.org/10.32747/2011.7697112.bard.
Testo completoAbstract (sommario):
The long-term goals of our research are to understand the regulation of sclerotial development and pathogenicity in S. sclerotiorum. The focus in this project is on the elucidation of the signaling events and environmental cues that contribute to broad pathogenic success of S. sclerotiorum. In this proposal, we have taken advantage of the recent conceptual (ROS/PPs signaling) and technical (genome sequence availability and gene inactivation possibilities) developments to address the following questions, as appear in our research goals stated below, specifically concerning the involvement of REDOX signaling and protein dephosphorylation in the regulation of hyphal/sclerotial development and pathogenicity of S. sclerotiorum. Our stated specific objectives were to progress our understanding of the following questions: (i) Which ROS species affect S. sclerotiorum development and pathogenicity? (ii) In what manner do PPs affect S. sclerotiorum development and pathogenicity? (iii) Are PPs affected by ROS production and does PP activity affect ROS production and SMK1? (iv) How does Sclerotinia modulate the redox environment in both host and pathogen? While addressing these questions, our main findings include the identification and characterization the NADPH oxidase (NOX) family in S. sclerotiorum. Silencing of Ssnox1 indicated a central role for this enzyme in both virulence and pathogenic (sclerotial) development, while inactivation of Ssnox2 resulted in limited sclerotial development but remained fully pathogenic. Interestingly, we found a consistent correlation with Ssnox1(involved with pathogenicity) and oxalate levels. This same observation was also noted with Sssod1. Thus, fungal enzymes involved in oxidative stress tolerance,when inactivated, also exhibit reduced OA levels. We have also shown that protein phosphatases (specifically PP2A and PTP1) are involved in morphogenesis and pathogenesis of S. sclerotiorum, demonstrating the regulatory role of these key proteins in the mentioned processes. While probing the redox environment and host-pathogen interactions we determined that oxalic acid is an elicitor of plant programmed cell death during S. sclerotiorum disease development and that oxalic acid suppresses host defense via manipulation of the host redox environment. During the course of this project we also contributed to the progress of understanding S. sclerotiorum function and the manipulation of this fungus by establishing an efficient gene replacement and direct hyphal transformation protocols in S. sclerotiorum. Lastly, both PIs were involved in thegenomic analysis of this necrotrophic fungal pathogen (along with Botrytis cinerea). Our results have been published in 11 papers (including joint papers and refereed reviews) and have set the basis for a continuum towards a better understanding and eventual control of this important pathogen (with implications to other fungal-host systems as well).
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Droby, Samir, Michael Wisniewski, Ron Porat e Dumitru Macarisin. Role of Reactive Oxygen Species (ROS) in Tritrophic Interactions in Postharvest Biocontrol Systems. United States Department of Agriculture, dicembre 2012. http://dx.doi.org/10.32747/2012.7594390.bard.
Testo completoAbstract (sommario):
To elucidate the role of ROS in the tri-trophic interactions in postharvest biocontrol systems a detailed molecular and biochemical investigation was undertaken. The application of the yeast biocontrol agent Metschnikowia fructicola, microarray analysis was performed on grapefruit surface wounds using an Affymetrix Citrus GeneChip. the data indicated that 1007 putative unigenes showed significant expression changes following wounding and yeast application relative to wounded controls. The expression of the genes encoding Respiratory burst oxidase (Rbo), mitogen-activated protein kinase (MAPK) and mitogen-activated protein kinase kinase (MAPKK), G-proteins, chitinase (CHI), phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and 4-coumarate-CoA ligase (4CL). In contrast, three genes, peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), were down-regulated in grapefruit peel tissue treated with yeast cells. The yeast antagonists, Metschnikowia fructicola (strain 277) and Candida oleophila (strain 182) generate relatively high levels of super oxide anion (O2−) following its interaction with wounded fruit surface. Using laser scanning confocal microscopy we observed that the application of M. fructicola and C. oleophila into citrus and apple fruit wounds correlated with an increase in H2O2 accumulation in host tissue. The present data, together with our earlier discovery of the importance of H₂O₂ production in the defense response of citrus flavedo to postharvest pathogens, indicate that the yeast-induced oxidative response in fruit exocarp may be associated with the ability of specific yeast species to serve as biocontrol agents for the management of postharvest diseases. Effect of ROS on yeast cells was also studied. Pretreatment of the yeast, Candida oleophila, with 5 mM H₂O₂ for 30 min (sublethal) increased yeast tolerance to subsequent lethal levels of oxidative stress (50 mM H₂O₂), high temperature (40 °C), and low pH (pH 4). Suppression subtractive hybridization analysis was used to identify genes expressed in yeast in response to sublethal oxidative stress. Transcript levels were confirmed using semi quantitative reverse transcription-PCR. Seven antioxidant genes were up regulated. Pretreatment of the yeast antagonist Candida oleophila with glycine betaine (GB) increases oxidative stress tolerance in the microenvironment of apple wounds. ROS production is greater when yeast antagonists used as biocontrol agents are applied in the wounds. Compared to untreated control yeast cells, GB-treated cells recovered from the oxidative stress environment of apple wounds exhibited less accumulation of ROS and lower levels of oxidative damage to cellular proteins and lipids. Additionally, GB-treated yeast exhibited greater biocontrol activity against Penicillium expansum and Botrytis cinerea, and faster growth in wounds of apple fruits compared to untreated yeast. The expression of major antioxidant genes, including peroxisomal catalase, peroxiredoxin TSA1, and glutathione peroxidase was elevated in the yeast by GB treatment. A mild heat shock (HS) pretreatment (30 min at 40 1C) improved the tolerance of M. fructicola to subsequent high temperature (45 1C, 20–30 min) and oxidative stress (0.4 mol-¹) hydrogen peroxide, 20–60 min). HS-treated yeast cells showed less accumulation of reactive oxygen species (ROS) than non-treated cells in response to both stresses. Additionally, HS-treated yeast exhibited significantly greater (P≥0.0001) biocontrol activity against Penicillium expansum and a significantly faster (Po0.0001) growth rate in wounds of apple fruits stored at 25 1C compared with the performance of untreated yeast cells. Transcription of a trehalose-6-phosphate synthase gene (TPS1) was up regulated in response to HS and trehalose content also increased.
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Watad, Abed A., Paul Michael Hasegawa, Ray A. Bressan, Alexander Vainstein e Yigal Elad. Osmotin and Osmotin-Like Proteins as a Novel Source for Phytopathogenic Fungal Resistance in Transgenic Carnation and Tomato Plants. United States Department of Agriculture, gennaio 2000. http://dx.doi.org/10.32747/2000.7573992.bard.
Testo completoAbstract (sommario):
The goal of this project is to enhance fungal resistance of carnation and tomato through the ectopic expression of osmotin and other pathogenesis-related (PR) proteins. The research objectives were to evaluate in vitro antifungal activity of osmotin and osmotin and other PR protein combinations against phytopathogens (including Fusarium oxysporum, Verticillium dahliae, Botrytus cinerea or Phytophthora infestans), develop protocols for efficient transformation of carnation and tomato, express PR proteins in transgenic carnation and tomato and evaluate fungal resistance of transgenic plants. Protocols for microprojectile bombardment and Agrobacterium-mediated transformation of carnation were developed that are applicable for the biotechnology of numerous commercial cultivars. Research established an efficient organogenetic regeneration system, optimized gene delivery and transgene expression and defined parameters requisite to the high frequency recovery of transgenic plants. Additionally, an efficient Agrobacterium-mediated transformation protocol was developed for tomato that is applicable for use with numerous commercial varieties. Rigorous selection and reducing the cytokinin level in medium immediately after shoot induction resulted in substantially greater frequency of adventitious shoots that developed defined stems suitable for rooting and reconstitution of transgenic plants. Transformation vectors were constructed for co-expression of genes encoding osmotin and tobacco chitinase Ia or PR-1b. Expression of osmotin, PR-1 and/or chitinase in transgenic carnation mediated a high level resistance of cv. White Sim (susceptible variety) to F. oxysporum f. sp. dianthi, race 2 in greenhouse assays. These plants are being evaluated in field tests. Comprehensive analysis (12 to 17 experiments) indicated that germination of B. cinerea conidia was unaffected by PR protein expression but germ tube elongation was reduced substantially. The disease severity was significantly attenuated by PR protein expression. Constitutive expression of osmotin in transgenic tomato increased resistance to B. cinerea, and P. infestans. Grey mold and late blight resistance was stable through the third selfed generation. The research accomplished in this project will have profound effects on the use of biotechnology to improve carnation and tomato. Transformation protocols that are applicable for efficient stable gene transfer to numerous commercial varieties of carnation and tomato are the foundation for the capacity to bioengineer these crops. The research further establishes that PR proteins provide a measure of enhanced disease resistance. However, considerations of PR protein combinations and conditional regulation and targeting are likely required to achieve; sustained level of resistance.