References of "Parisi, Olivier"
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See detailMode of Action of Lactoperoxidase as Related to Its Antimicrobial Activity: A Review
Bafort, Françoise ULg; Parisi, Olivier ULg; Perraudin, Jean-Paul et al

in Enzyme Research (2014), 2014

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See detailDevelopment of a colorimetric method for the dosage of OI- anions and I2 in aqueous media
Bafort, Françoise ULg; Barthelemy, Jean-Paul ULg; Parisi, Olivier ULg et al

in Communications in Agricultural and Applied Biological Sciences (2014), 79(1), 155-160

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See detailINCIDENCE DES MALADIES BACTERIENNES ET FONGIQUES DU RIZ A MADAGASCAR
Mamiharisoa Razanakoto, Léa ULg; De Clerck, Caroline ULg; Massart, Sébastien ULg et al

Poster (2013, December)

Le riz, c’est à la fois la culture la plus cultivée à Madagascar mais aussi la principale base de l’alimentation des malgaches. Même si le pays est à vocation agricole, l’autosuffisance alimentaire n’a ... [more ▼]

Le riz, c’est à la fois la culture la plus cultivée à Madagascar mais aussi la principale base de l’alimentation des malgaches. Même si le pays est à vocation agricole, l’autosuffisance alimentaire n’a jamais été atteinte, et l’importation de riz est toujours importante chaque année. Pour le riz, les maladies constituent le facteur entraînant la mauvaise qualité et la réduction des récoltes. C’est la raison qui nous amène à réaliser le suivi de la maladie de riz présent à Madagascar. L’incidence de la maladie a été évalué par l’observation visuelle des symptômes au champ et l’identité des pathogènes a été confirmée par les tests au laboratoire. Pour cela un échantillonnage a été réalisé dans les régions de Vakinankaratra, Analamanga et Atsinanana. Une enquête a été réalisée durant l’échantillonnage pour récolter les informations qui peuvent nous aider à l’identification de l’agent pathogène. L’isolement a été réalisé en utilisant les milieux standards pour bactéries et pour champignons. Les isolats ont été ensuite identifiés par l’observation des colonies sur boite de Pétri, par des observations microscopique des cellules en présence de différents colorants. Elles ont ensuite été identifiées par analyse moléculaire par séquençage.Dans les régions du haut plateau : les symptômes trouvés sont très variés et l’incidence de chaque symptôme est faible sauf le flétrissement des feuilles de riz. Dans la région Atsinanana, les symptômes trouvés ne varient pas et l’incidence est proche de 100 %. L’isolement des microorganismes à partir d’échantillons de chacune de ces régions confirme les résultats obtenus : Xanthomonas oryzae pv. oryzae correspondait à l’espèce pathogène dominante pour les hauts plateaux tandis que Curvularia lunata correspondait à l’espèce pathogène dominante pourAtsinanana. Ces différences trouvent probablement leur origine dans les conditions climatiques et le mode de culture très différentes entre cette région côtière et les hauts plateaux. [less ▲]

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See detailMicroscale ELISA plate screening of essential oils against European damageable plant pathogens
Parisi, Olivier ULg; Zhiri, Abdesselam; Baudoux, Dominique et al

Conference (2013, March)

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See detailRole of satellite RNAs in cucumber mosaic virus-host plant interactions. A review
Kouadio, Kouakou Théodore ULg; De Clerck, Caroline ULg; Agneroh, Thérèse Atcham et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(4), 644-650

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See detailDiagnosis of Pathogens responsible of pre-and post-harvest rice diseases in Madagascar
Razanakoto Mamiharisoa, Lea; De Clerck, Caroline ULg; Parisi, Olivier ULg et al

Poster (2013)

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See detailMicroscale ELISA plate screening of essential oils against European damageable plant pathogens
Parisi, Olivier ULg; Zhiri, Abdesselam; Baudoux, Dominique et al

Conference (2012, June)

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See detailMicroscale ELISA plate screening of essential oils against European damageable plant pathogens
Parisi, Olivier ULg; Zhiri, Abdesselam; Baudoux, Dominique et al

Conference (2012)

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See detailMolecular characterization of the host-pathogen relationships involved during an infection of GF-305 peach trees by the Peach latent mosaic viroid (PLMVd)
Parisi, Olivier ULg

Doctoral thesis (2011)

The Peach latent mosaic viroid (PLMVd) infects peach trees in all production areas. This pathogen is responsible of direct and indirect crop losses. However only a few data are available as regards on one ... [more ▼]

The Peach latent mosaic viroid (PLMVd) infects peach trees in all production areas. This pathogen is responsible of direct and indirect crop losses. However only a few data are available as regards on one hand the determinant of pathogenicity of this viroid and on the other hand the resistance mechanisms of plants against this pathogen. The original approach of this work was to give the foundation of this double characterization. Firstly, the role of the P8 pseudoknot, present in every sequenced PLMVd, was studied by directed mutagenesis. Secondly, the molecular response of different peach trees infected by different variants was evaluated by the use of the cDNA-AFLP. The main objective of this thesis was to identify a metabolic pathway implicated in the plant defence against the PLMVd. In the term of this work, it seemed that the P8 pseudoknot was implicated either in the stability or in the replication of the viroid into the infected cells. Indeed, the inoculated variant (with a destabilized pseudoknot) has shown a reduced replication during the cultural season. In spite of the presence of the mutated variant in the plants, no symptom was observed on the peach tree leaves. However, we cannot conclude if this absence of symptom is due to the low viroid quantity either to an implication of the pseudo-knot in the pathogenicity of the PLMVd. The characterization of the gene expression in the infected peach trees has allowed to highlight that the PLMVd represses genes implicated in the photosynthesis and more specifically genes involved in the protection of the two photosystems. This particular gene expression in the infected leaves was linked to the chlorosis and mosaic induced by the PLMVd. However, we cannot conclude with certitude if these symptoms are a cause or a consequence of this particular genes expression. The cDNA-AFLP has also allowed to identify the repression of genes coding for heat shock proteins (HSPs) in symptomatic leaves. These proteins generally have a role in the protein folding, assembly, translocation, stabilization and degradation. The regulation of their expression may have a great influence in the infected plants and, maybe, play a role in the symptoms expression. The gene coding for the novel cap-binding protein (nCBP) was also identified has repressed in the symptomatic leaves. The biological role of these proteins is unclear but it seems that these proteins act in the regulation of the mRNA translation. The repression of nCBP may thus have an important impact and to destabilize various biological pathways. Finally, two genes implicated in the plant defence were identified. One coding for a polygalacturonase inhibitor (over-expressed in symptomatic leaves) and the other one coding for a thiamine intermediate (involved in the SAR and over-expressed in the non-symptomatic leaves). The role of these proteins in the plant defence against the PLMVd is however unclear. To our knowledge, this is the first work where the host-pathogen relationship established during a PLMVd infection are studied. This is also the first time were the gene expression is linked to the viroid-induced symptoms. [less ▲]

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See detailDevelopment of a Quick Quantitative Real-Time PCR for the In Vivo Detection and Quantification of Peach latent mosaic viroid
Parisi, Olivier ULg; Lepoivre, Philippe ULg; Jijakli, Haissam ULg

in Plant Disease (2011), 95(2), 137-142

Viroids are plant pathogens infecting a broad range of herbaceous and tree crops. Among them, the Peach latent mosaic viroid (PLMVd) infects mainly peach trees, causing a loss of production with no ... [more ▼]

Viroids are plant pathogens infecting a broad range of herbaceous and tree crops. Among them, the Peach latent mosaic viroid (PLMVd) infects mainly peach trees, causing a loss of production with no curative options. Detecting this viroid is thus important for certification procedures aiming to avoid the release of infected material into orchards. Presented here is a complete detection method based on reverse transcription (RT) followed by a quantitative real-time polymerase chain reaction (PCR). New primers were selected and optimal reaction conditions determined for routine application of the method. The technique is 105 times more sensitive than the endpoint RT-PCR used for PLMVd detection, and permits earlier detection of PLMVd in infected plants. The quick, low-cost extraction procedure used and the quality of the results obtained make this method suitable for routine testing. [less ▲]

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See detailPlant-RNA viroid relationship: a complex host pathogen interaction
Parisi, Olivier ULg; Lepoivre, Philippe ULg; Jijakli, Haissam ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(3),

Viroids are non encapsidated small RNA plant pathogens unable to produce any protein. They are able to infect dramatically a broad range of plants including herbaceous and tree crops. The ways by which ... [more ▼]

Viroids are non encapsidated small RNA plant pathogens unable to produce any protein. They are able to infect dramatically a broad range of plants including herbaceous and tree crops. The ways by which viroids are able to induce diseases are actually unknown. However, recent studies have shown that viroids are able to regulate the gene expression of their hosts, they can modify the host-protein phosphorylation sensibility and they interact with host-protein implicated RNA trafficking and protein phosphorylation. Moreover during their evolution plants have developed a mechanism able to regulate their gene expression and to degrade exogenous RNAs like viroids: the gene silencing. Unfortunately, this pathway seems, now, also highly implicated in the symptoms development. This review describes studies that are realized since a few years to increase the knowledge about the plant-viroid relationship. [less ▲]

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See detailContribution à la caractérisation moléculaire des relations hôte-pathogène de plants de pêchers infectés par le viroïde de la mosaïque latente du pêcher (PLMVd)
Parisi, Olivier ULg

Master of advanced studies dissertation (2007)

Since several years, the Plant Pathology Unit studies the Peach latent mosaic viroid (PLMVd) and other viroids from fruit trees. These studies have led, first, to the lightening of new pseudoknot ... [more ▼]

Since several years, the Plant Pathology Unit studies the Peach latent mosaic viroid (PLMVd) and other viroids from fruit trees. These studies have led, first, to the lightening of new pseudoknot interactions potentially involved in the pathogenic mecanisms of the PLMVd. Secondly the existence of recombination events during the replication of the viroids was expressed. The first goal of this work was to create a collection of dimeric variants to be able to verify these hypothesys during the following years. Dimeric constructions of severe and latent variants were successfully obtained. Unfortunately, the variants selected to perform the recombination analysis contained too much mutations to be used. Finally two design of specific primers were performed. The first provides the possibility to create mutations in the pseudoknots and the second makes us able to detect recombinant variants. The second goal of this work was to set up the cDNA-AFLP on peach extracts to perform the caracterization of host-pathogen interactions between peach trees and the PLMVd.This will be made with collaboration of the Biochemistry and Catalityc RNA Departement of the Universtiy of Sherbrooke wich will analyze the miRNA pattern of infected and healthy plants. Based on former pathogenicity studies of differents variants performed in our Departement, the comparison of differentially expressed genes will include symptomatic and non symptomatic plants and also an healthy plant. Total RNA extracts were successfully performed and a first AFLP profile was obtained. However some steps of the manipulation need an optimization to produce reliable results. [less ▲]

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See detailEtude de la pathogénicité de différents variants du viroïde de la mosaïque latente du pêcher (PLMVd) et mise au point d'une technique de détection du phénomène d'extinction post-transcriptionnelle de gènes (Posttranscriptional gene silencing)
Parisi, Olivier ULg

Master's dissertation (2006)

Le Peach latent mosaïc viroïd (PLMVd) est étudié depuis plusieurs années à l’Unité de Phytopathologie. Ces recherches ont permis, entre autres, le développement de techniques moléculaires de détection (RT ... [more ▼]

Le Peach latent mosaïc viroïd (PLMVd) est étudié depuis plusieurs années à l’Unité de Phytopathologie. Ces recherches ont permis, entre autres, le développement de techniques moléculaires de détection (RT-PCR) et de quantification (rétro-transcription suivie de PCR en temps réel) de ce viroïde. Elles ont été utilisées ici pour caractériser la réplication de variants mutés par rapport à un variant de référence non muté. Les mutations réalisées concernent le pseudo-noeud P8 (variant P8) et le domaine ribozyme du viroïde (variant 6A). Ces variants mutés et non mutés ont été inoculés sur des plants de pêcher de la variété GF-305. Les résultats obtenus par quantification absolue du PLMVd au cours des neuf derniers mois ont montré que ces mutations ont eu un impact négatif sur la réplication du viroïde. En moyenne, les titres en PLMVd mesurés ont été respectivement 80 fois inférieurs et 320 fois inférieurs après inoculation par les variants 6A et P8 par rapport aux titres rencontrés dans les plants inoculés par le variant de référence. Ces deux variants mutés ont induit des symptômes de mosaïque sévère dans un premier temps et de mosaïque légère par la suite. Les mutations introduites ont pu amener à la réduction du taux de réplication ou d’auto-clivage de ces variants, favoriser leur dégradation via la RNA silencing et/ou affecter la relation hôte-pathogène. Il est également probable que les variants mutés aient été incapables de se maintenir ou de se répliquer dans les plants mais que des mutations compensatoires soient apparues in vivo et aient restauré leur activité. [less ▲]

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See detailStudies on the infectivity and pathogenicity of new Peach Latent Mosaic viroid (PLMVd) variants
Fekih Hassen, I.; Parisi, Olivier ULg; Fakhfakh, H. et al

Poster (2006)

Detailed reference viewed: 17 (3 ULg)