References of "Du Jardin, Patrick"
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See detailAllo- and autoinhibition in barley and great brome: a laboratory study
Bouhaouel, Imen ULg; Gfeller, Aurélie; Fauconnier, Marie-Laure ULg et al

Conference (2014, February 08)

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See detailRhizobacterial volatile organic compounds implication in Brachypodium distachyon response to phosphorus deficiency
Baudson, Caroline ULg; Saunier de Cazenave-Mendaluk, Magdalena ULg; du Jardin, Patrick ULg et al

Poster (2014, February 07)

In agriculture, phosphorus (P) is considered as the second most growth-limiting macronutrient after nitrogen. However, P fertilizers are produced from non-renewable resources. In this context, sustainable ... [more ▼]

In agriculture, phosphorus (P) is considered as the second most growth-limiting macronutrient after nitrogen. However, P fertilizers are produced from non-renewable resources. In this context, sustainable production strategies have to be developed to enhance P use efficiency of crops, e.g. based on naturally occurring biotic interactions that limit the negative impacts of P deficiency in soils. Plant growth-promoting rhizobacteria (PGPR) have already revealed their ability to promote plant growth and tolerance to abiotic stresses through many mechanisms. Among them, the bacterial volatile organic compounds-mediated communication between plants and PGPR is still poorly documented. Our research project aims at studying the capacity of a model cereal plant (Brachypodium distachyon (L.) Beauv. Bd21) to face P deficiency in interaction with PGPR. The prerequisite of this project consists in characterizing Bd21 response to P deficiency by measuring plant biomass production and allocation, root system architecture, total phosphorus content, root-secreted and intracellular acid phosphatase activity under various P concentrations. Those results will allow us to define P-limiting conditions, in order to assess PGPR volatiles influence on plant response to P deficiency. This approach will use an ex-vitro co-cultivation system allowing volatiles-mediated interaction and should help us to unravel the ability of rhizobacterial volatiles to enhance plant tolerance to P deficiency. [less ▲]

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See detailQuantitative gas chromatography - mass spectrometry profiling of volatile organic compounds produced by barley (Hordeum distichon L.) roots according to plant age
Delory, Benjamin ULg; Delaplace, Pierre ULg; du Jardin, Patrick ULg et al

Poster (2014, February 07)

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In ... [more ▼]

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In this context, this study aims at developing a fully automated analytical methodology allowing both identification and accurate quantification of VOCs produced by roots of a monocotyledon plant species. Briefly, VOC emitted by crushed barley roots are successively trapped by dynamic headspace sampling on Tenax TA adsorbents, thermally desorbed and cryofocused, separated by gas chromatography (GC) and finally analysed by mass spectrometry (MS) in both SCAN and selected ion monitoring modes. Results show that barley roots mainly produce four volatile aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal and (E,Z)-nona-2,6-dienal. These molecules are well-known linoleic (C18:2) and linolenic (C18:3) acid derivatives produced via the lipoxygenase and the hydroperoxide lyase pathways of higher plants. Our findings contrast with analyses documented on aboveground barley tissues that mainly emit C6 aldehydes, alcohols and their derivative esters. Moreover, preliminary results indicate quantitative changes in the volatile profile contained in barley roots according to plant age. Multivariate statistical analyses are currently underway to quantitatively assess these changes using plants at five selected developmental stages ranging from germination to the end of tillering. [less ▲]

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See detailarchiDART: a R package allowing root system architecture analysis using Data Analysis of Root Tracings (DART) output files
Delory, Benjamin ULg; Baudson, Caroline ULg; Brostaux, Yves ULg et al

Poster (2014, February 07)

In 2010, Le Bot et al presented a free and open-access software (Data Analysis of Root Tracings - DART) allowing the analysis of complex root system architectures from captured images, particularly across ... [more ▼]

In 2010, Le Bot et al presented a free and open-access software (Data Analysis of Root Tracings - DART) allowing the analysis of complex root system architectures from captured images, particularly across time series. Using this software, a user has to manually identify roots as a set of links. After vectorization of a root system, three final data sets (RAC, TPS and LIE) can be exported as table files containing several attributes for (a) each individual root (e.g. root length), (b) each observation day or (c) each point used to construct the vectorized root system respectively. These data sets can finally be used either to calculate derived root system architecture (RSA) parameters or to draw the root system architecture at selected observation dates. However when an experiment involves the analysis and comparison of many root systems, the calculation of RSA parameters for each data set and the drawing of the corresponding vectorized root systems become time-consuming. In this context, we developed a R package, called archiDART, allowing both the automatic calculation of common root architecture parameters and the X-Y plotting of vectorized root systems for selected observation dates. [less ▲]

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See detailAllelopathic potential of sunflower against the great brome
Bouhaouel, Imen ULg; Gfeller, Aurélie; Fauconnier, Marie-Laure ULg et al

Poster (2014, February 06)

Control methods commonly used to suppress the great brome (Bromus diandrus Roth., syn. Bromus rigidus Roth. subsp. gussonii Parl.) in Tunisian cereal crop are essentially chemical, raising both efficacy ... [more ▼]

Control methods commonly used to suppress the great brome (Bromus diandrus Roth., syn. Bromus rigidus Roth. subsp. gussonii Parl.) in Tunisian cereal crop are essentially chemical, raising both efficacy and safety issues. The introduction of allelopathic species into the crop rotation or utilizing allelopathic plants as living/green mulches has been suggested as a cost-effective way to reduce the weed presence. Among these species, the sunflower (Helianthus annuus L.) has shown an allelopathic potential against some troublesome weed species. In this study, we analyzed the biological activities of water extract of different tissues (root, shoot, leaf and flower) of sunflower on the seedling establishment of the great brome. In a second experiment, the allelopathic influence of sunflower residues (leaf or flower) against this weed was also studied under glasshouse conditions at more advanced stages of growth using different concentrations (0, 6, 12 and 18g tissue dry weight / kg of soil). The first experiment showed an effect depending on the parts of the sunflower. Indeed, the roots seem to be the less allelopathic part (22% of root inhibition growth) as compared to the leaves and flowers (82% and 100%, respectively). This potential seems to simultaneously affect the radicle and the coleoptile growth of the great brome. In the second experiment, weed growth was inhibited in a dose-dependent manner, using increasing amounts of sunflower residues. The allelopathic potential of the leaves or flowers reduced both the root or shoot length and biomass accumulation of the weed. These results suggest that the sunflower can be a good previous crop for cereal cultivation by controlling the presence of some weeds, including the great brome. In this perspective, the inhibitory effects of sunflower residues on cultivated cereals in the field need to be assessed. [less ▲]

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See detailReprogramming of fatty acid and oxylipin synthesis in rhizobacteria-induced systemic resistance in tomato
Mariutto, Martin; Fauconnier, Marie-Laure ULg; Ongena, Marc ULg et al

in Plant Molecular Biology (2013), Online First Articles

The rhizobacterium Pseudomonas putida BTP1 stimulates induced systemic resistance (ISR) in tomato. A previous work showed that the resistance is associated in leaves with the induction of the first enzyme ... [more ▼]

The rhizobacterium Pseudomonas putida BTP1 stimulates induced systemic resistance (ISR) in tomato. A previous work showed that the resistance is associated in leaves with the induction of the first enzyme of the oxylipin pathway, the lipoxygenase (LOX), leading to a faster accumulation of its product, the free 13-hydroperoxy octadecatrienoic acid (13-HPOT), 2 days after Botrytis cinerea inoculation. In the present study, we further investigated the stimulation of the oxylipin pathway: metabolites and enzymes of the pathway were analyzed to understand the fate of the 13-HPOT in ISR. Actually the stimulation began upstream the LOX: free linolenic acid accumulated faster in P. putida BTP1-treated plants than in control. Downstream, the LOX products 13-fatty acid hydroperoxides esterified to galactolipids and phospholipids were more abundant in bacterized plants than in control before infection. These metabolites could constitute a pool that will be used after pathogen attack to produce free fungitoxic metabolites through the action of phospholipase A2, which is enhanced in bacterized plants upon infection. Enzymatic branches which can use as substrate the fatty acid hydroperoxides were differentially regulated in bacterized plants in comparison to control plants, so as to lead to the accumulation of the most fungitoxic compounds against B. cinerea. Our study, which is the first to demonstrate the accumulation of an esterified defense metabolite during rhizobacteria-mediated induced systemic resistance, showed that the oxylipin pathway is differentially regulated. It suggests that this allows the plant to prepare to a future infection, and to respond faster and in a more effective way to B. cinerea invasion. [less ▲]

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See detailInfluence of rhizobacterial volatile compounds on growth and root system architecture of Brachypodium distachyon (L.) Beauv.
Mendaluk, Magdalena ULg; Varin, Sébastien; Baudson, Caroline ULg et al

Poster (2013, February 08)

Many rhizobacterial strains are classified as plant growth-promoting rhizobacteria (PGPR) and are potentially useful to enhance plant fitness and productivity. Among the mechanisms by which PGPR improve ... [more ▼]

Many rhizobacterial strains are classified as plant growth-promoting rhizobacteria (PGPR) and are potentially useful to enhance plant fitness and productivity. Among the mechanisms by which PGPR improve plant growth, the emission of volatile organic compounds (VOCs) and their biological impacts on plants remain little documented. The aim of this work is to evaluate the growth promotion ability of 19 bacterial strains on the model grass Brachypodium distachyon Bd21 (Bd21), with a focus on this peculiar mode of interaction. A collection of 19 strains was selected for their known growth promotion potential. The impact of the rhizobacteria on the model grass was studied using an in vitro cocultivation system allowing interactions through VOCs without physical contact between plants and bacteria. The results show that the VOCs of several strains promote total biomass production, modulate biomass partitioning and affect shoot and root architecture of Bd21. The effects of the PGPR strains emitting different volatile blends were investigated via principal component analysis coupled to clustering and univariate analysis to unravel their biological effects. On the basis of volatile emissions and of their effects on plant growth, two strains have been selected in order to evaluate such interactions using an ex vitro system. The set-up of this system is in progress. [less ▲]

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See detailDevelopment of an experimental device allowing plant-plant interaction studies and in situ dynamic trapping of volatile organic compounds emitted by barley (Hordeum distichon L.) roots
Delory, Benjamin ULg; Delaplace, Pierre ULg; Fauconnier, Marie-Laure ULg et al

in Communications in Agricultural and Applied Biological Sciences (2013, February 08), 78(1), 97-102

In response to wounding or herbivore attack, leaves and roots of higher plants release volatile organic compounds (VOCs). To date, VOCs analysis and plant−plant interaction studies have been mainly ... [more ▼]

In response to wounding or herbivore attack, leaves and roots of higher plants release volatile organic compounds (VOCs). To date, VOCs analysis and plant−plant interaction studies have been mainly performed on aboveground plant tissues, leaving the roles played by root VOCs in plant−plant interaction unexplored. In this context, this project aims at setting up an original experimental device allowing both dynamic trapping of VOCs emitted by mechanically damaged H. distichon roots and the study of the roles played by root VOCs in intra and interspecific plant−plant interactions. The experimental device consists of Barley seedlings cultivated in closed PTFE reactors filled with wet sand. Before being analysed by gas chromatography−mass spectrometry, root VOCs are trapped via a dynamic system on Tenax cartridges using a charcoal-filtered and humidified air. Preliminary results show that 7 day-old wounded Barley roots emit C9 fatty acid derivatives (E-non-2-enal and nona-2,6-dienal) as major compounds, contrasting with aboveground plant tissues that mainly emit C6 alcohols, aldehydes, and their derivative esters. For plant−plant interaction studies, receiver plants are exposed to an airflow enriched with VOCs from root damaged Barley plants of the same age. [less ▲]

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See detailImplication of microRNAs in the response of Brachypodium distachyon (L.) Beauv. root system architecture to rhizobacterial volatiles
Baudson, Caroline ULg; Bouché, Frédéric ULg; Saunier de Cazenave, Magdalena ULg et al

Scientific conference (2013, February)

The metabolic roles of volatile organic compounds (VOCs) emitted by plant growth-promoting rhizobacteria (PGPR) and the identity of the molecules responsible for the growth promotion are still poorly ... [more ▼]

The metabolic roles of volatile organic compounds (VOCs) emitted by plant growth-promoting rhizobacteria (PGPR) and the identity of the molecules responsible for the growth promotion are still poorly documented. As well, the implication of microRNAs in root development is a recent discovery that deserves to be explored. In this study, the implication of microRNAs in the response of Brachypodium distachyon (L.) Beauv. Bd21 root architecture to rhizobacterial VOCs was investigated. Nineteen PGPR strains were screened to select those showing the strongest phenotypic effects. The strain Bacillus subtilis AP305-GB03 induced the most important promotion of biomass production and root development. Total RNA extraction and RT-qPCR analysis of microRNAs were performed on Bd21 root samples. The expression of miR160 a-d, miR164 f, miR167 c-d, miR397 b and miR399 a-b was measured in roots every 2 days during the first 10 days of Bd21 development, in the presence or absence of the bacterial VOCs. Differences in the expression profile of miR164 f and miR167 c-d were observed in the roots exposed to GB03 VOCs, as compared to the control. These differences could be correlated to the root system architecture modifications observed after 10 days of growth with GB03. miR397 b and miR399 a-b also showed differences in the expression profile of roots exposed to the bacterial VOCs. These microRNAs have been respectively involved in cold stress tolerance and in the response to phosphate starvation. [less ▲]

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See detailCharacterization of volatile organic compounds emitted by Barley (Hordeum vulgare L.) roots and their attractiveness to wireworms
Gfeller, Aurélie; Laloux, Morgan; Barsics, Fanny ULg et al

in Journal of Chemical Ecology (2013), 39(8), 1129-1139

Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here for the first time on the identification ... [more ▼]

Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here for the first time on the identification of VOCs emitted by barley roots (Hordeum vulgare L.). Twenty nine VOCs were identified from isolated 21-d-old roots. The detection of root volatiles was dependent on the medium used for root cultivation. From 7-d-old roots cultivated on sterile Hoagland gelified medium, 24 VOCs were identified, on sterile vermiculite 33 VOCs, and on non-sterile vermiculite 34 VOCs. The major VOCs identified were fatty acid derived compounds, including hexanal, methyl hexanoate, (E)-hex-2-enal, 2-pentylfuran, pentan-1-ol, (Z)-2-(pentenyl)-furan, (Z)-pent-2-en-1-ol, hexan-1-ol, (Z)-hex-3-en-1-ol, (E)-hex-2-en-1-ol, oct-1-en-3-ol, 2-ethylhexan-1-ol (likely a contaminant), (E)-non-2-enal, octan-1-ol, (2E,6Z)-nona-2,6-dienal), methyl (E)-non-2-enoate, nonan-1-ol, (Z)-non-3-en-1-ol, (E)-non-2-en-1-ol, nona-3,6-dien-1-ol and nona-2,6-dien-1-ol. In an olfactometer assay, wireworms (larvae of Agriotes sordidus Illiger, Coleoptera: Elateridae) were attracted to chemical cues emanating from barley seedlings. We discuss the role of individual root volatiles or a blend of the root volatiles detected here and their interaction with CO2for wireworm attraction. [less ▲]

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See detailImprovement of Ylang-Ylang Essential Oil Characterization by GCxGC-TOFMS
Brokl, Michal ULg; Fauconnier, Marie-Laure ULg; Benini, Céline et al

in Molecules (2013), 18(2), 1783-1797

A single fraction of essential oil can often contain hundreds of compounds. Despite of the technical improvements and the enhanced selectivity currently offered by the state-of-the-art gas chromatography ... [more ▼]

A single fraction of essential oil can often contain hundreds of compounds. Despite of the technical improvements and the enhanced selectivity currently offered by the state-of-the-art gas chromatography (GC) and mass spectrometry (MS) instruments, the complexity of essential oils is frequently underestimated. Comprehensive two-dimensional GC coupled to time-of-flight MS (GC×GC-TOFMS) was used to improve the chemical characterization of ylang-ylang essential oil fractions recently reported in a previous one-dimensional (1D) GC study. Based on both, the enhanced chromatographic separation and the mass spectral deconvolution, 161 individual compounds were identified and labeled as potentially characteristic analytes found in both low and high boiling fractions issued from distillation of mature ylang-ylang flowers. Compared to the most recent full GC-MS characterization, this represents 75 new compounds, essentially consisting of terpenes, terpenoid esters, and alcohols. [less ▲]

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See detailAllelopathic potential of Tunisian barley against weeds
Bouhaouel, Imen ULg; Gfeller, Aurélie; Fauconnier, Marie-Laure ULg et al

Poster (2012, December)

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See detailPlant growth- promoting rhizobacteria emit volatiles compounds with biostimulation activity in dicot and monocot plant species.
du Jardin, Patrick ULg; Delaplace, Pierre ULg; Varin, Sébastien et al

in Perata, Pierdomenico; Brown, Patrick; Ponchet, Michel (Eds.) Abstracts Book for Oral and Poster Presentations of the 1st World Congress on the use of Biostimulants in Agriculture (2012, November)

Detailed reference viewed: 12 (3 ULg)