References of "Fauconnier, Marie-Laure"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailCould alternative solanaceous hosts act as refuges for the tomato leafminer, Tuta absoluta?
Bawin, Thomas ULg; Dujeu, David ULg; De Backer, Lara ULg et al

in Arthropod-Plant Interactions (2015), 9(4), 425-435

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous plants. The characterization of its effective ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous plants. The characterization of its effective host range could help to understand and prevent the dispersion behavior of the insect in the environment. In this study, the ability of T. absoluta to locate and develop on wild (Solanum nigrum, Atropa belladonna, Datura stramonium) and cultivated (Solanum tuberosum) solanaceous plant species under laboratory conditions was assessed. Dual-choice behavioral assays performed in flying tunnels (S. tuberosum versus another plant) revealed that adult distribution and female oviposition did not differ between Solanum species, which were preferred to the other tested plants. The volatile molecules released by each tested plant species provide some explanations in the observed behavioral discrimination: S. nigrum and S. tuberosum volatile profiles were similar, and were presenting quantitative and qualitative differences with the other tested Solanaceous plants. To determine whether the host plant choice was adaptive or not, we have finally conducted fitness assays, by rearing T. absoluta larvae on each plant species and have shown that Solanum species allowed higher larval survivability and lower development time (from egg to adult emergency) compared to the other plants. We conclude that Solanum species are suitable host plants for T. absoluta, but other Solanaceous plant species could be opportunistically colonized with fewer incidences. [less ▲]

Detailed reference viewed: 71 (19 ULg)
Full Text
Peer Reviewed
See detailPhysicochemical properties and thermal behaviour of African wild mango (Irvingia gabonensis) seed fat
Yamoneka, J.; Malumba Kamba, Paul ULg; Blecker, Christophe ULg et al

in LWT - Food Science and Technology (2015), 64

African wild mango (Irvingia gabonensis) is now recognized for its numerous food and medicinal uses. This plant produces seeds rich in fat, which is traditionally used as a soup thickener. In the present ... [more ▼]

African wild mango (Irvingia gabonensis) is now recognized for its numerous food and medicinal uses. This plant produces seeds rich in fat, which is traditionally used as a soup thickener. In the present study, the fat from Irvingia gabonensis seeds was solvent extracted and characterized. Besides a chemical characterization (fatty acid (FA) and triacylglycerol (TG) profiles), the melting and crystallization behaviour of the extracted fat was studied by complementary techniques: pNMR, DSC and X-ray diffraction in order to get basic information regarding its physical properties and more particularly, about its polymorphism. The seeds from Irvingia gabonensis (IG) represent an important source of lipids (69e75 g/100 g), rich in myristic (49.8%) and lauric acid (37%). Due to its FA composition, this fat can be classified among “lauric fats”. The melting profiles of IG fat indicates that a high amount of fat remains solid at temperatures up to 30 °C; the complete melting was detected at around 40 °C. The most stable polymorph of this fat is the ℬ' 1-form. Moreover, IG fat presents a good oxidative stability due to its low content in unsaturated fatty acid. [less ▲]

Detailed reference viewed: 26 (6 ULg)
Full Text
See detailScreening for interesting elicitors to protect wheat against Zymoseptoria tritici
Le Mire, Géraldine ULg; Siah, Ali; Fauconnier, Marie-Laure ULg et al

Conference (2015, May 19)

Plants face an array of biotic and abiotic stresses in their environment, making it necessary to use various chemical inputs to maintain satisfactory yield. Today, conventional agriculture is evolving ... [more ▼]

Plants face an array of biotic and abiotic stresses in their environment, making it necessary to use various chemical inputs to maintain satisfactory yield. Today, conventional agriculture is evolving towards more sustainable practices, out of respect for human health and the environment. Elicitors are considered as promising biological control tools and draw major interest in IPM strategies. These plant-immunity triggering compounds, also called “stimulators of plant natural defenses”, induce a general and systemic resistance in the plant to various diseases. Although numerous elicitors have already been identified and some of them reached the market since the late 1970s, further investigations are still required to better understand the mode of action of these molecules in the plant and ensure a consistent efficiency under various field conditions. Few elicitors have yet been successfully tested and formulated to protect crop plants such as wheat, which is cultivated over large areas in Europe. This study focuses on the screening of ten potential elicitor products of various origins and structures to protect winter wheat against the fungal pathogen Zymoseptoria tritici. Greenhouse trials were carried out to measure the ability of the different products to reduce disease foliar symptoms (necrosis, chlorosis and pycnidia). In addition, the phytotoxicity and biocide activities of these products were evaluated under greenhouse and laboratory conditions, respectively. The corresponding results will be presented and discussed with the perspective to choose the best elicitor candidates and to undertake investigations on the signaling pathway and the influence of environmental parameters on the elicitation capacity. [less ▲]

Detailed reference viewed: 71 (24 ULg)
Peer Reviewed
See detailSurfactin: a receptor-independent bacterial elicitor of plant immunity?
Luzuriaga Loaiza, Walter ULg; Legras, Aurelien; Crowet, Jean-Marc ULg et al

Poster (2015, May 13)

Detailed reference viewed: 39 (3 ULg)
Full Text
See detailThe CROSTVOC project – an integrated approach to study the effect of stress on BVOC exchange between agricultural crops and grassland ecosystems and the atmosphere
Amelynck, Crist; Heinesch, Bernard ULg; Aubinet, Marc ULg et al

in Geophysical Research Abstracts (2015, April), 17

Global changes in atmospheric composition and climate are expected to affect BVOC exchange between terrestrial vegetation and the atmosphere through changes in the drivers of constitutive BVOC emissions ... [more ▼]

Global changes in atmospheric composition and climate are expected to affect BVOC exchange between terrestrial vegetation and the atmosphere through changes in the drivers of constitutive BVOC emissions and by increases in frequency and intensity of biotic or abiotic stress episodes. Indeed, several studies indicate changes in the emission patterns of constitutive BVOCs and emission of stress-induced BVOCs following heat, drought and oxidative stress, amongst others. Relating changes in BVOC emissions to the occurrence of one or multiple stressors in natural environmental conditions is not straightforward and only few field studies have dealt with it, especially for agricultural crop and grassland ecosystems. The CROSTVOC project aims to contribute in filling this knowledge gap in three ways. Firstly, it aims at performing long-term BVOC emission field measurements from maize (Zea mays L.) and wheat (Triticum aestivum L.), two important crop species on the global scale, and from grassland. This should lead to a better characterization of (mainly oxygenated) BVOC emissions from these understudied ecosystems, allowing a better representation of those emissions in air quality and atmospheric chemistry and transport models. BVOC fluxes are obtained by the Disjunct Eddy Covariance by mass scanning (DEC-MS) technique, using a hs-PTR-MS instrument for BVOC analysis. Secondly, the eddy covariance BVOC flux measurements (especially at the grassland site) will be accompanied by ozone flux, chlorophyll fluorescence, photosynthesis and soil moisture measurements, amongst others, to allow linking alterations in BVOC emissions to stress episodes. Simultaneously, automated dynamic enclosures will be deployed in order to detect specific abiotic and biotic stress markers by PTR-MS and identify them unambiguously by GC-MS. Thirdly, the field measurements will be accompanied by laboratory BVOC flux measurements in an environmental chamber in order to better disentangle the responses of the BVOC emissions to driving factors that co-occur in field conditions and to determine the influence of single abiotic stressors on BVOC emissions. Next to a general presentation, some preliminary results of the project will be shown. [less ▲]

Detailed reference viewed: 111 (13 ULg)
Full Text
See detailBiogenic Volatile Organic Compound (BVOC) emissions from agricultural crop species: is guttation a possible source for methanol emissions following light/dark transition?
Mozaffar, Ahsan ULg; Amelynck, Crist; Bachy, Aurélie ULg et al

in Geophysical Research Abstracts (2015, April), 17(EGU2015-2110-1),

In the framework of the CROSTVOC (CROp STress VOC) project, the exchange of biogenic volatile organic compounds (BVOCs) between two important agricultural crop species, maize and winter wheat, and the ... [more ▼]

In the framework of the CROSTVOC (CROp STress VOC) project, the exchange of biogenic volatile organic compounds (BVOCs) between two important agricultural crop species, maize and winter wheat, and the atmosphere has recently been measured during an entire growing season by using the eddy covariance technique. Because of the co-variation of BVOC emission drivers in field conditions, laboratory studies were initiated in an environmental chamber in order to disentangle the responses of the emissions to variations of the individual environmental parameters (such as PPFD and temperature) and to diverse abiotic stress factors. Young plants were enclosed in transparent all-Teflon dynamic enclosures (cuvettes) through which BVOC-free and RH-controlled air was sent. BVOC enriched air was subsequently sampled from the plant cuvettes and an empty cuvette (background) and analyzed for BVOCs in a high sensitivity Proton-Transfer Reaction Mass Spectrometer (hs-PTR-MS) and for CO2 in a LI-7000 non-dispersive IR gas analyzer. Emissions were monitored at constant temperature (25 °C) and at a stepwise varying PPFD pattern (0-650 µmol m-2 s-1). For maize plants, sudden light/dark transitions at the end of the photoperiod were accompanied by prompt and considerable increases in methanol (m/z 33) and water vapor (m/z 39) emissions. Moreover, guttation droplets appeared on the sides and the tips of the leaves within a few minutes after light/dark transition. Therefore the assumption has been raised that methanol is also coming out with guttation fluid from the leaves. Consequently, guttation fluid was collected from young maize and wheat plants, injected in an empty enclosure and sampled by PTR-MS. Methanol and a large number of other compounds were observed from guttation fluid. Recent studies have shown that guttation from agricultural crops frequently occurs in field conditions. Further research is required to find out the source strength of methanol emissions by this guttation phenomenon in real environmental conditions. [less ▲]

Detailed reference viewed: 90 (8 ULg)
Full Text
See detailPhysicochemical properties and thermal behaviour of African wild mango (Irvingia gabonensis) seed oil.
Yamoneka, Juste; Malumba Kamba, Paul ULg; Blecker, Christophe ULg et al

Poster (2015, March 15)

African wild mango (lrvingia gabonensis) is now recognized for its numerous food and medicinal uses. This plant produces seeds rich in fat, which is traditionally used as a soup thickener. in the present ... [more ▼]

African wild mango (lrvingia gabonensis) is now recognized for its numerous food and medicinal uses. This plant produces seeds rich in fat, which is traditionally used as a soup thickener. in the present study, the proximate composition of seeds from lrvingia gabonensis is reported. The oil from the seeds was then solvent extracted; its fatty acid (FA) and triacylglycerol (TG) profiles were determined. Besides this chemical characterization, the melting and crystallization behaviour of the extracted fat was studied by pNMR, DSC and X-ray diffraction. The result of this investigation showed that the seeds from lrvingia gabonensis (IG) represent an important source of lipids (69-75%), rich in myristic (49.8%) and lauric acid (37%). This fat can be classified among "lauric fats". IG oil presents a good oxidative stability due to its low content in unsaturated fatty acid. The melting profiles of IG oil indicates that a high amount of fat remains solid at temperatures up to 30°C; the complete melting was detected at around 40C. The most stable polymorph of this fat is the β'1 -form. [less ▲]

Detailed reference viewed: 44 (9 ULg)
See detailPhysicochemical properties and thermal behaviour of African wild mango (Irvingia gabonensis) seed oil.
Yamoneka, Juste; Malumba Kamba, Paul ULg; Blecker, Christophe ULg et al

Poster (2015, March 15)

Plants belonging Dacryodes and lrvingia genus have great economic importance in Central and West Africa. lrvingia gabonensis (IG) produces a seed rich in fats, traditionally used as a soup thickener ... [more ▼]

Plants belonging Dacryodes and lrvingia genus have great economic importance in Central and West Africa. lrvingia gabonensis (IG) produces a seed rich in fats, traditionally used as a soup thickener. Fruit of Dacryodes edulis (DS) contains a pulp how are also rich in fat. Its seed constitute a big waste problem in towns and village remains not exploitable by local people however that may be valued as a resource for various components. Some study shows that this seed contented a proportion of oils that would be an alternative in the substitution of diesel relevant to their physicochemical properties. Despite the potential of two different oils, theirs scientific data still lack. In this work, thermo-physical behaviour of those two oils is compared in the aim to improving knowledge about properties of those oils that will promote their valorisation in industry scale. The result of this investigation showed that IGO have a highest proportion of oil content with 72.38% compared to DSO (14.64%). IGO is rich in myristic (49.8%) and lauric fatty acid (37%) but DSO sample was found to possess a higher proportion of linoleic acid (35.13%), palmitic (32.67%), oleic (17.70%) but lower proportion of stearic (9.97%). SFC of IGO was the highest at all temperatures. IGO is solid at room temperature with a complete melting at 40°C but DSO is liquid at room temperature. The polymorphism profile of IGO and DSO shows the 13' form stable during heating and a transition to liquid state without passage at β form. [less ▲]

Detailed reference viewed: 40 (10 ULg)
Full Text
Peer Reviewed
See detailElicitation of the defence mechanisms at plant case of Cucumis melo
Ydjedd, Siham; Kati, D.E.; Fauconnier, Marie-Laure ULg

Poster (2015, January 30)

The judicious use of elicitors could reduce the amount of pesticide necessary to protect crops and preservation of the environment. This strategy frequently called "stimulation of natural defenses ... [more ▼]

The judicious use of elicitors could reduce the amount of pesticide necessary to protect crops and preservation of the environment. This strategy frequently called "stimulation of natural defenses" arouses more and more interest in the phytosanitary field. [less ▲]

Detailed reference viewed: 52 (5 ULg)
Full Text
Peer Reviewed
See detailInteractions of natural rhamnolpids produced by Pseudomonas aeruginosa with plant model membranes
Polo Lozano, Damien ULg; Nasir, Mehmet Nail ULg; Deleu, Magali ULg et al

Poster (2015, January 30)

It is well known that chemical pesticides have harmful effects on human health and environment. In this context, the interest for alternative products such as biopesticides is increasing. Among them ... [more ▼]

It is well known that chemical pesticides have harmful effects on human health and environment. In this context, the interest for alternative products such as biopesticides is increasing. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. Rhamnolipids are surface active molecules produced mainly by various strains of the bacterium Pseudomonas aeruginosa. These secondary metabolites are composed of one to three fatty acids with various chain lengths linked through a glycosidic bond to one or two rhamnose moieties. The fatty acids are linked together through an ester bond. These molecules have shown several biological activities including plant defense stimulation. It has been suggested that this elicitor activity could be related to an interaction of rhamnolipids with the lipid bilayer of the plant plasma membrane (PPM) and lead to its destabilization, which can activate the plant defense signaling pathways. In this context, interactions of two rhamnolipids (Rha-C10-C10 and Rha-Rha-C10-C10) with biomimetic membranes of PPM such as Langmuir monolayers and multilayers were investigated using biophysical and in silico approaches. [less ▲]

Detailed reference viewed: 69 (5 ULg)
Full Text
See detailInvestigating the Effects of Plant Root Exudates on PAHs Bioavailability to Soil Microorganisms in Contaminated Brownfields : Research Methodology.
Davin, Marie ULg; Lognay, Georges ULg; Fauconnier, Marie-Laure ULg et al

Poster (2015, January 30)

As a result of heavy industrial past activities, an estimated 6,000 brownfields require remediation in Wallonia. This number rises to over 3.5 million in Europe. Polycyclic Aromatic Hydrocarbons (PAHs ... [more ▼]

As a result of heavy industrial past activities, an estimated 6,000 brownfields require remediation in Wallonia. This number rises to over 3.5 million in Europe. Polycyclic Aromatic Hydrocarbons (PAHs) represent 17% of treated pollutants in Wallonia (Aldric et al., 2011). Current remediation techniques are rather expensive and technically demanding (Megharaj et al., 2011). Based on the observation that PAHs soil content decreases in the presence of plants (Cheema et al., 2010), the PhD aims at developing alternative PAHs remediation techniques in brownfields. It is articulated around three research axes. The first axis focusses on plant exudates and how they may improve PAHs bioavailability to soil microorganisms and enhance their degradation. This will be investigated by (i) characterizing several contaminated soils (physico-chemical parameters) and PAH content and factors of bioavailability, (ii) selecting a plant model and collecting root exudates, and (iii) evaluating the effects of exudates on PAHs bioavailability. The objective of the second axis is to evaluate the effects of plant exudates on PAHs degrading microorganisms by (i) comparing PAHs biodegradation in the presence/absence of exudates and (ii) assessing the potential toxic effects of exudate compounds on the microbial communities. The aim of the third axis is to study plant-pollutants interactions by (i) establishing the plant tolerance to several contamination levels and (ii) following PAHs bioavailability when facing real exudation rates, on the field. [less ▲]

Detailed reference viewed: 59 (7 ULg)
Full Text
See detailEvaluation et gamification - Transformer un quiz de chimie en un mini-jeu
le Maire, Nathalie ULg; Fauconnier, Marie-Laure ULg; Colaux, Catherine ULg et al

Conference (2015, January 30)

Le recours à des questionnaires à choix multiples pour l’évaluation des étudiants est une pratique courante à l’université. Cette communication décrit et analyse une expérimentation contrôlée visant à ... [more ▼]

Le recours à des questionnaires à choix multiples pour l’évaluation des étudiants est une pratique courante à l’université. Cette communication décrit et analyse une expérimentation contrôlée visant à explorer les effets de la présentation d’un QCM formatif sous la forme d’un jeu. L’étude s’inscrit ainsi dans les recherches actuelles sur les avantages et les limites pédagogiques de la « gamification », à savoir la transposition des principes issus de l’univers du jeu au domaine de l’éducation (Johnson, Adams Becker, Estrada, & Freeman, 2014). La présente recherche est effectuée dans le cadre d’un doctorat dédié spécifiquement à la gamification d’évaluations formatives. L’étude repose sur la mise à disposition de plusieurs versions d’un quiz portant sur un chapitre d’un cours de chimie générale en première année d’université. Le dispositif expérimental prévoit un enrichissement graduel de la gamification selon quatre prototypes conçus après identification et extraction de schèmes visant à stimuler et maintenir la motivation et la performance dans des jeux actuels et populaires tels que Candy Crush, Angry Birds ou Hay Day. Située à l’entrée du doctorat, cette étude vise, outre la collecte de données quant à l’utilisabilité du mini-jeu proposé, à mettre en lumière ses effets sur l’état de flow dans le contexte des edugames et contribuera à la validation de la traduction française de l’échelle d’EGameFlow (Fu, Su, & Yu, 2009). [less ▲]

Detailed reference viewed: 100 (15 ULg)
Full Text
Peer Reviewed
See detailManufacturing of Kivuguto milk and stability in storage under refrigeration
Karenzi, Eugène; Fauconnier, Marie-Laure ULg; Destain, Jacqueline ULg et al

in European Scientific Journal (2015), 11(3), 1-16

The kivugutomilk was processed in a 20 liters bioreactor with three bacteria previously selected in kivuguto traditional milk. The work aimed to study the association of three bacteria previously selected ... [more ▼]

The kivugutomilk was processed in a 20 liters bioreactor with three bacteria previously selected in kivuguto traditional milk. The work aimed to study the association of three bacteria previously selected in traditional kivuguto in order to reproduce it in a controlled fermentation, and thereafter to understand its stability during storage under refrigeration. Postacidification, viability, proteolysis, flavor compounds as well as rheological characteristics were monitored for 36 days. The ph decreases from 4.54 to 4.45 and the titratable acidity grew from 73°d to 79°d. The final biomass after storage was 0.60 108 cfu.g-1 which is far higher than the recommended 106 cells.g-1before consumption. The proteolysis was at a range of 3.0 to 7.0 mg.l-1of lysine equivalent, which is too low so that it can’t produce bitter peptides. The evolution of flavor compounds in storage showed that no change found with 3-methylbutan-1-ol, acetic acid and furan-2(5h)-one, whilst pentan-1-ol and furanmethan-2-ol increased slightly upon 24 days’ storage. The complex viscosity decreased from 4 - 5.3 pas before storage to 2.9 - 4.0 pas corresponding respectively to the ratio g''/g' of about 0.3-0.4 with a very low variation. These data allowed the production and the good preservation of kivuguto milk at 4°c on 36 days. [less ▲]

Detailed reference viewed: 41 (8 ULg)