References of "Lepoivre, Philippe"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailcDNA-AFLP analysis of gene expression changes in apple trees induced by phytoplasma infection during compatible interaction
Aldaghi, Majid; Bertaccini, Assunta; Lepoivre, Philippe ULg

in European Journal of Plant Pathology (2012), 134

Abstract In order to gain insight into molecular and physiological changes in apple trees during compatible interaction with two ‘Candidatus Phytoplasma mali’ strains (AP and AT), cDNA-Amplified Fragment ... [more ▼]

Abstract In order to gain insight into molecular and physiological changes in apple trees during compatible interaction with two ‘Candidatus Phytoplasma mali’ strains (AP and AT), cDNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) technique was used. A rootstock of apple (MM106) susceptible to ‘Ca. P. mali’ was used to extend the range of the potential host responses by the maximum number of identified genes that will be deregulated by phytoplasma in apple. Gene expression comparisons were studied in three directions: healthy versus infected samples, symptomatic versus nonsymptomatic sample, and AP-infected versus ATinfected sample. Forty-five genes whose steady-state levels of expression significantly changed in response to phytoplasma infection were identified. Among their partial cDNA sequences, only 27 showed similarity to DNA or protein data bases; of these, 18 were related to known genes in plants, and the rest were related to unknown or hypothetical proteins. Eighteen out of 45 did not show any similarity with sequences in data bases (potential novel genes). Quantitative real-time RT-PCR (qRT-PCR) was used to confirm differential expression of AFLP identified genes, and showed the similar profile expression for 11 known genes among 18, and for 13 unknown, hypothetical or novel genes among 27. Changes in gene expression involved a wide spectrum of biological functions, including processes of metabolism, cell defence, senescence, photosynthesis, transport, transcription, signal transduction and protein synthesis. This is the first study of global gene profiling in plants in response to phytoplasma infections using cDNA-AFLP, and a model is proposed to explain the mode of action of the ‘Ca. P. mali’ in apple. [less ▲]

Detailed reference viewed: 54 (1 ULg)
Full Text
See detailLes volatils racinaires de l’orge : un langage souterrain ?
Barsics, Fanny ULg; Gfeller, Aurélie ULg; Fauconnier, Marie-Laure ULg et al

Scientific conference (2011, October 13)

Cette présentation résume les avancées du projet Rhizovol après une année de travaux de recherche.

Detailed reference viewed: 74 (31 ULg)
Full Text
See detailBiocontrol proteomics:Implication of the pentoses phosphates pathway in the antagonist effect of Pichia anomala against Botrytis cinerea on apple
Kwasiborski, Anthony ULg; Renaut, Jenny; Lepoivre, Philippe ULg et al

Poster (2011, September 21)

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to ... [more ▼]

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to apply biological control methods. Pichia anomala strain K was previously identified as an efficient biocontrol agent of the main apple pathogens, Botrytis cinerea and Penicillum expansum. Further study demonstrated the complexicity of the mode of action of P. anomala against B. cinerea. A cDNA-AFLP and gene disruption study revealed implication of exo-β-1,3-glucanases in the mode of action of P. anomala strain Kh6 (a haploid form of P. anomala strain K displaying the same biocontrol properties). However, these studies suggested also implication of other factors. The present study aims to increase our knowledge of the mode of action of P. anomala strain Kh6 against B. cinerea using an in situ approach allowing the triple interaction, host/pathogen/antagonist and the proteomic tool allowing to study the ultime expression of the genome without a priori. One 50mm wound per apple were covered by a membrane and inoculated by a P. anomala suspension then by B. cinerea or not. Samples were collected during the exponential and stationary phase to identify the early and later responses to the presence of B. cinerea. After extraction, proteins were separated on 2-D gels. Spots influenced by the presence of B. cinerea in exponential and stationary phases were identified by MALDI-ToF. One hundred five and sixty spots of proteins were influenced by the presence of B. cinerea in exponential and stationary phases respectively. In exponential phase, P. anomala Kh6 in absence of B. cinerea uses mainly the glycolysis pathway, whereas in presence of pathogen, it orientates its energetic metabolism to the oxidative phosphorylation and sets up the pentose phosphate pathway. Thanks to this new orientation, P. anomala Kh6 probably obtains energy and nucleic acids allowing to colonize the wound as fast as in absence of B. cinerea and prevents the use of nutrients by the pathogen. In stationary phase, no differences in the P. anomala Kh6 energetic metabolism, in absence and in presence of B. cinerea were observed. During that phase, P. anomala Kh6 seems to use the alcoholic fermentation in order to face the nutrients impoverishment of the substrate. [less ▲]

Detailed reference viewed: 36 (0 ULg)
Full Text
See detailBiocontrol proteomics:Implication of the pentoses phosphates pathway in the antagonist effect of Pichia anomala against Botrytis cinerea on apple.
Kwasiborski, Anthony ULg; renaut, Jenny; Delaplace, Pierre ULg et al

Conference (2011, August 31)

Pichia anomala strain K was previously identified as an efficient biocontrol agent of the apple pathogen, Botrytis cinerea. Further study demonstrated the complexicity of the mode of action of P. anomala ... [more ▼]

Pichia anomala strain K was previously identified as an efficient biocontrol agent of the apple pathogen, Botrytis cinerea. Further study demonstrated the complexicity of the mode of action of P. anomala against B. cinerea. A molecular study revealed implication of exo-β-1,3-glucanases in the mode of action of P. anomala but suggested implication of other factors. The present study aims to increase our knowledge of the mode of action of P. anomala strain Kh6 against B. cinerea using an in situ approach allowing interactions between organisms, and the proteomic tool allowing to study the ultime expression of the genome. One wound per apple were covered by a membrane and inoculated by P. anomala then by B. cinerea or not. Samples were collected at different incubation times to identify the responses of P. anomala to the presence of B. cinerea. After extraction, proteins were separated on 2-D gels. Spots influenced were identified by MALDI-ToF. In exponential phase, P. anomala Kh6 orientates its energetic metabolism from the glycolysis to the oxidative phosphorylation and sets up the pentose phosphate pathway. Thanks to this new pathway, P. anomala probably obtains energy and nucleic acids allowing to colonize the wound as fast as in absence of B. cinerea. In stationary phase, no differences in the P. anomala energetic metabolism, in absence and in presence of B. cinerea were observed. During that phase, P. anomala seems to use the alcoholic fermentation in order to face the nutrients impoverishment of the substrate. [less ▲]

Detailed reference viewed: 56 (3 ULg)
Full Text
See detailVolatile organic compounds of the roots of barley and their role in the rhizosphere
Fiers, Marie ULg; Barsics, Fanny ULg; Camerman, Marc ULg et al

Poster (2011, May 24)

Volatile organic compounds emitted by plants are known to intervene with various biotic environmental factors. Up to now, most of the studies have been focused on aerial volatiles and root liquid exudates ... [more ▼]

Volatile organic compounds emitted by plants are known to intervene with various biotic environmental factors. Up to now, most of the studies have been focused on aerial volatiles and root liquid exudates. Very few researches have been completed concerning belowground volatiles released into the rhizosphere despite their potential capacity to carry information between organisms. The Rhizovol project, started in autumn 2010, involves 5 different units of Gembloux Agro-Bio Tech collectively studying the production of belowground volatiles by barley roots underlying various biotic interactions in the rhizosphere. Some preliminary results of each partner of the project will be presented. To achieve this goal, analytical methods allowing the sampling, separation, identification and quantification of belowground volatile compounds have to be developed, taking into account their potential modifications in the rhizosphere once released by the roots. They enable the subsequent characterization and study of the interactions between barley and its rhizospheric partners chosen for this study. These interactions imply three types of organisms: beneficial organisms, pathogenic agents and plant and insect pests. Beneficial organisms can promote the growth of barley by the emission of volatiles; on the other hand barley can support their growth and metabolism. These phenomenons will be assessed by the study of 19 strains of plant growth-promoting bacteria (PGPR). Three pathogenic agents - two fungi (Fusarium culmorum and Cochliobolus sativus) and one virus (Barley yellow dwarf virus) - were chosen as they are known to cause various diseases on barley, especially on roots. The attractive or repellent effects of barley root volatiles on the pathogenic agents or their vectors, as well as the effect of volatiles on the diseases evolution will be evaluated. The project also includes several types of pests such as plants and insects. Plants can compete with barley for space and nutrients through volatile interactions. This will be assessed by the study of autotoxicity by barley itself and allelopathy with 8 weeds and a hemiparasitic plant (Rhinanthus minor). The effects of barley volatiles can also impact the severity of the attacks by insects. This part will be conducted with wireworms as they represent worldwide known pests, and aphids, through their viral vector role. Eventually, as soil characteristics can strongly influence the diffusion of volatile compounds, the diffusion behaviour of the identified volatile biomolecules through the soil will be modelled. Tritrophic interactions (e.g. insect-plant-pathogenic fungi) will be studied based on each bitrophic interaction results. Over-all, the Rhizovol project aims at improving the knowledge of interactions mediated by volatile compounds in the rhizosphere and at establishing new biocontrol methods that could contribute to integrated disease and pest management systems. [less ▲]

Detailed reference viewed: 40 (7 ULg)
Full Text
See detailIn situ proteome study of Pichia anomala strain K, an antagonist of the apple pathogen Botrytis cinerea
Kwasiborski, Anthony ULg; Renaut, Jenny; Delaplace, Pierre ULg et al

Conference (2011, May 24)

Postharvest fungal pathogens, mainly Botrytis cinerea, Penicillum expansum and Gloeosporium spp., annually cause 5-20% losses of fruit. Control measures against these diseases include chemical fungicide ... [more ▼]

Postharvest fungal pathogens, mainly Botrytis cinerea, Penicillum expansum and Gloeosporium spp., annually cause 5-20% losses of fruit. Control measures against these diseases include chemical fungicide applications, but the development of resistant fungal explains the growing interest for biological control. Pichia anomala strain K was previously identified as an efficient antagonist of pathogens on apples. Indeed, the percentage of protection of P.anomala against B.cinerea reached from 90 to 100% on apple wounds according to the experimental conditions. Microbiological, biochemical and molecular approaches demonstrated the implication of exo-β-1,3-glucanases in the mechanism of action of P.anomala. However, study of these mechanisms could be improved by observations under natural infection conditions in order to take into account the tripartite interactions host/antagonist/pathogen. The proteomic tool allowed an overview of process implicated in the antagonism against B.cinerea in such conditions. One 50mm wound per apple were covered by a membrane and inoculated by a P.anomala suspension then by B.cinerea or not. Samples were collected during the exponential and stationary phase to identify the early and later responses to the presence of B.cinerea. After extraction, proteins were separated on 2DE gels. Spots influenced by the presence of B.cinerea in exponential and stationary phases were identified by MALDI-ToF. One hundred five and sixty spots of proteins were influenced by the presence of B.cinerea in exponential and stationary phase respectively. In exponential phase, influenced proteins were implicated in the different steps of the proteins biosynthesis: amino acid synthesis, translation or mRNA maturation and in energy synthesis. On the other hand, in stationary phase, influenced proteins were mainly implicated in energy metabolic pathway: glycolysis, alcoholic fermentation or gluconeogenesis. The presence of B.cinerea seemed to induce a slowdown in the metabolism of P.anomala without influenced its growth. Further studies have to be realized to understand the complexity of these modes of action. [less ▲]

Detailed reference viewed: 37 (0 ULg)
Full Text
See detailScreening Elisa method to assess in vitro efficacy of new agents based on Lactoperoxydase system against phytopathogens
Bafort, Françoise ULg; Lepoivre, Philippe ULg; Jijakli, Haissam ULg et al

Poster (2011, May 24)

The lactoperoxydasesystem (LPS) is a natural biological protection system in human saliva, milk and tears. Lactoperoxydase catalyzes the oxidation of iodide (I-) and thiocyanate (SCN-) in presence of ... [more ▼]

The lactoperoxydasesystem (LPS) is a natural biological protection system in human saliva, milk and tears. Lactoperoxydase catalyzes the oxidation of iodide (I-) and thiocyanate (SCN-) in presence of hydrogen peroxide in hypoiodite (OI-) and hypothiocyanite (OSCN-) ions. Both ions have inhibitory action against pathogenic bacteria, fungi and viruses. Until now, the ions OI- and OSCN- applied separately from the LPS were not tested against plant pathogens. Seventeen KI/KSCN/H2O2 ratios with 3 dilutions for each one were tested against Botrytiscinerea. Results showed that the ions OI- and OSCN- gives a better % of inhibition with: -high concentration of KI+KSCN, -a ratio of KI/KSCN of 4.5 and -a ratioof (KI+KSCN)/H2O2 near 1. Increased dilution combined with lower KI+KSCN concentration reduced the efficacy of the ions. From the screening against B.cinerea, 4 ratios of KI+KSCN were selected and tested against 6 other phytopathogens. Results showed that the OI- and OSCN- ions give 87 and 100% inhibition against Penicillium expansum and Verticillium dahlia respectively. The inhibitory activity of the ions solution was ranged between 70 and 79% regarding Fusarium avenaceum, Phytophthora infestans and Colletotrichum lindemuthanium. The ions OI- and OSCN- showed an insufficient inhibitory activity against Septoria tritici. The screening method highlighted that high KI/KSCN ratios and low dilution were more efficient against phytopathogens. The efficient ratios will be further evaluated in vivo. [less ▲]

Detailed reference viewed: 74 (24 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 45 (1 ULg)
Full Text
Peer Reviewed
See detailCatecholamine biosynthesis pathway potentially involved in banana defense mechanisms to crown rot disease
Lassois, Ludivine ULg; De Clerck, Caroline ULg; Frettinger, Patrick et al

in Communications in Agricultural and Applied Biological Sciences (2011), 76(4), 591-601

Detailed reference viewed: 45 (4 ULg)
Full Text
Peer Reviewed
See detailPredictive modelling of the combined effect of temperature and water activity (aw) on the in vitro growth of Erwinia spp infecting potato tubers in Belgium
Moh, Augustin; Massart, Sébastien ULg; Lahlali, Rachid et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2011), 15(3), 378-386

Detailed reference viewed: 33 (11 ULg)
Full Text
Peer Reviewed
See detailNew genetic sources of resistance in the genus Phaseolus to individual and combined aluminium toxicity and progressive soil drying stresses
Butare, Louis; Rao, I. M.; Lepoivre, Philippe ULg et al

in Euphytica : International Journal of Plant Breeding (2011), 181(3), 384-404

Bean species and genotypes show wide phenotypic variability in relation to aluminium (Al) resistance and progressive soil drying. The objective of this study was to identify and characterize sources of ... [more ▼]

Bean species and genotypes show wide phenotypic variability in relation to aluminium (Al) resistance and progressive soil drying. The objective of this study was to identify and characterize sources of resistance to Al toxicity and progressive soil drying among six genotypes of common bean (Phaseolus vulgaris), four of runner bean (P. coccineus), and one of tepary bean (P. acutifolius), using hydroponic and soil cylinder screening methods. One experiment on hydroponic screening of Al resistance was carried out using a basal nutrient solution with and without 20 lM Al. Two experiments were carried out using two oxisols in 80 cm long soil cylinders with high Al (HAl) and low Al (LAl) saturation treatments. The three experiments showed an average of 36.9–53.5% inhibition of root growth with HAl compared with LAl treatments. Differences in root development and distribution were observed among genotypes and species. Two accessions of P. coccineus (G35346-2Q, G35464-5Q) and one Andean common bean genotype (ICA Quimbaya) were outstanding in root and shoot growth in the HAl treatments. P. coccineus accession (G35346-3Q) was outstanding under combined stress of Al-toxic acid soil and progressive soil drying. Accessions of P. coccineus may represent unique sources of Al resistance for the improvement of common bean through interspecific crosses. [less ▲]

Detailed reference viewed: 80 (2 ULg)
Full Text
Peer Reviewed
See detailPhenotypic evaluation of interspecific recombinant inbred lines (RILs) of Phaseolus species for their resistance to aluminum and tolerance to aluminum-toxic acid soil under greenhouse conditions
Butare, Louis; Rao, I. M.; Lepoivre, Philippe ULg et al

in Euphytica : International Journal of Plant Breeding (2011)

Aluminium (Al) toxicity limits common bean productivity in acid soil regions of the tropics. To improve Al resistance of common bean, Al-sensitive Phaseolus vulgaris (SER16) was crossed to Alresistant P ... [more ▼]

Aluminium (Al) toxicity limits common bean productivity in acid soil regions of the tropics. To improve Al resistance of common bean, Al-sensitive Phaseolus vulgaris (SER16) was crossed to Alresistant P. coccineus (G35346-3Q) to create 94 F5:6 recombinant inbred lines (RILs) of the pedigree SER16 9 (SER16 9 G35346-3Q). RILs were characterized for resistance to Al in a hydroponic system with 0 and 20 lM Al in solution, and for shoot and root growth response to Al-toxic infertile acid soil in 75 cm long soil cylinder system using an oxisol of low Al- (12.5%; pH 4.6; fertilized) and high Al-saturation (77%; pH 4.1; unfertilized). G35346-3Q increased its taproot elongation rate by 3.5% between 24 and 48 h under 20 lM Al in solution, while the best RIL, Andean genotype ICA Quimbaya, and sensitive genotype VAX1 expressed reductions of 2.6, 12.5, and 69.5%, respectively. In the acid soil treatment the correlation between leaf area and total root length was highly significant under high Al saturation (r = 0.70***). Genotypes that were Al resistant in the hydroponic system were not necessarily tolerant to Al-toxic acid soil conditions based on shoot and root growth responses. Phenotypic evaluation using both systems allows the identification of genotypes with Al resistance combined with acid soil adaptation. Two genotypes (ALB88 and ALB91) emerged as lines with multiple traits. Results suggest that inheritance of Al resistance and acid soil tolerance in G35346-3Q is complex. Results from this work will be useful for identification of molecular markers for Al resistance in Phaseolus species and to improve acid soil adaptation in common bean. [less ▲]

Detailed reference viewed: 56 (5 ULg)
Full Text
Peer Reviewed
See detailIdentification of genes involved in the response of banana to crown rot disease
Lassois, Ludivine ULg; Frettinger, Patrick; de Lapeyre de Bellaire, Luc et al

in Molecular Plant-Microbe Interactions [=MPMI] (2011), 24(1), 143-153

Detailed reference viewed: 77 (15 ULg)
Peer Reviewed
See detailEvaluation of three essential oils as potential source of botanical fungicide
Kouassi, Kouadio Hugues Sosthène ULg; Bajji, M.; Zhiri, A. et al

Conference (2010)

Detailed reference viewed: 338 (12 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 90 (3 ULg)