References of "Jijakli, Haissam"
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See detailThe Science, development, and commercialization of postharvest biocontrol products
Droby, Samir; Wisniewski, Michael; Teixido, Neus et al

in Postharvest Biology & Technology (in press)

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See detailReview: Implementing biostimulants and biocontrol strategies in the agroecological management of cultivated ecosystems
Le Mire, Géraldine ULg; Nguyen, Minh ULg; Fassotte, Bérénice ULg et al

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

This review describes the current methods for exploiting and applying plant growth-promoting rhizbacteria (PGPR), elicitors and semiochemical products in contemporary agricultural systems. The future of ... [more ▼]

This review describes the current methods for exploiting and applying plant growth-promoting rhizbacteria (PGPR), elicitors and semiochemical products in contemporary agricultural systems. The future of these biostimulant and biocontrol tools for the sustainable management of agricultural practices is also discussed. Special attention is given to the formulation of these products and the network of interactions taking place in cultivated ecosystems [less ▲]

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See detailNew elicitors to protect wheat against Zymoseptoria tritici: biocontrol tools for IPM strategies
Le Mire, Géraldine ULg; SIAH, Ali; BRISSET, Marie-Noëlle et al

Conference (2016, May 17)

Elicitors are increasingly considered as promising biocontrol tools in the preventive treatment of plants against various diseases. These plant-immunity triggering compounds, also called “stimulators of ... [more ▼]

Elicitors are increasingly considered as promising biocontrol tools in the preventive treatment of plants against various diseases. These plant-immunity triggering compounds, also called “stimulators of plant natural defenses”, induce a general and systemic resistance of the plant to a large spectrum of biotic stresses. Today, focus is made on the crucial protection of wheat, as one of the most cultivated crop plants in the world. This crop is constantly challenged by a persistent and harmful fungus known as Zymoseptoria tritici, responsible of the Septoria Tritici Blotch (STB) disease. Control of this disease mainly depends on phytosanitary products, and the social and economic importance of wheat make it all the more urgent to identify and develop new elicitors as biocontrol tools in wheat IPM strategies. This study focuses on the screening of nine molecules of various origins and structures for their potential eliciting properties to protect winter wheat against Zymoseptoria tritici. Three products were selected after screening trials in greenhouse conditions: EGL1, EGL4, and EGL5. They were efficient to reduce foliar disease symptoms from 40 to 80%. The biocide activity and phytotoxicity of these 3 products were evaluated directly towards the pathogen and the plant under laboratory and greenhouse conditions, respectively. On the other hand, the triggered signaling pathways were investigated by studying the activity of the defense-related enzymes lipoxygenase (LOX), peroxidase (POX) and phenylalanine ammonia-lyase (PAL) in treated wheat leaves. In addition, the expression of five defense genes (lox, pal, pox2, chi, pr1) was studied by qRT-PCR in wheat leaves treated with these elicitors and/or inoculated with Zymoseptoria tritici. The corresponding results will be presented and discussed, with the perspective to investigate the influence of environmental parameters on the elicitation capacity and the efficacy of the elicitors in field conditions. [less ▲]

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See detailTout ce qui pousse au potager d'intérieur
Jijakli, Haissam ULg

Article for general public (2016)

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See detailNew elicitors as biocontrol tools to protect wheat against Septoria Tritici Blotch
Le Mire, Géraldine ULg; SIAH, Ali; Jijakli, Haissam ULg

Poster (2016, April)

Wheat is one of the most cultivated crops in the European Union. This cereal must however face important losses every year due to a major foliar disease known as Septoria Tritici Blotch (STB) caused by ... [more ▼]

Wheat is one of the most cultivated crops in the European Union. This cereal must however face important losses every year due to a major foliar disease known as Septoria Tritici Blotch (STB) caused by the fungus Zymoseptoria tritici. Disease control mainly depends on phytosanitary products. However, 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 Integrated Pest Management strategies. These plant-immunity triggering compounds induce a general systemic resistance of the plant to a large spectrum of diseases. This study focuses on the screening of nine potential elicitors to protect winter wheat against 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 biocide activity of these products towards the pathogen was evaluated under greenhouse and laboratory conditions. Furthermore, the modes of action of the best elicitors were investigated by studying the activity of some key defense enzymes of wheat. The corresponding results will be presented and discussed with the perspective to choose the two best elicitors for field trials and undertake further investigations on the signaling pathways triggered in the plant. [less ▲]

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See detailGembloux veut sauver les oliviers
Jijakli, Haissam ULg

Article for general public (2016)

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See detailUne solution belge pour sauver les oliviers du sud de l'Italie?
Jijakli, Haissam ULg

Article for general public (2016)

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See detailBioncontrol of wheat against Septoria Tritici Blotch: new elicitors
Le Mire, Géraldine ULg; SIAH, Ali; Jijakli, Haissam ULg

Poster (2016, February 05)

Wheat is one of the most cultivated crop plants in the world. However, this plant must constantly face numerous biotic challenges, including major yield losses every year (up to 30-50%) due to a foliar ... [more ▼]

Wheat is one of the most cultivated crop plants in the world. However, this plant must constantly face numerous biotic challenges, including major yield losses every year (up to 30-50%) due to a foliar disease known as Septoria Tritici Blotch (STB). This persistent and harmful disease is caused by the fungus Zymoseptoria tritici. Disease control mainly depends on phytosanitary products. However, 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 for Integrated Plant Management (IPM) strategies. Contrary to conventional products, these natural compounds do not inhibit directly the pathogen but induce a general and systemic resistance in the plant to a large spectrum of diseases. The natural defense mechanisms of the plant are thus stimulated. Few elicitors have yet been successfully tested and formulated to protect wheat against STB. This study focuses on the screening of ten potential elicitor products of various origins and structures to protect winter wheat against 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 biocide activity of these products directly towards the pathogen was evaluated under greenhouse and laboratory conditions, respectively. The corresponding results will be presented and discussed with the perspective to choose the best elicitor candidates for field trials and to undertake further investigations on the signaling pathways, and the influence of environmental parameters, on the elicitation capacity. [less ▲]

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See detailDes légumes sur le bitume : L'agriculture urbaine est en plein développement
Jijakli, Haissam ULg

Article for general public (2016)

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See detailToits potagers, bonus immobilier
Jijakli, Haissam ULg

Article for general public (2015)

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See detailLes villes mangeables
Jijakli, Haissam ULg

Article for general public (2015)

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See detailAgriculture Urbaine: quatre modules pour un certificat
Jijakli, Haissam ULg

Article for general public (2015)

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See detailA metagenomic approach from aphid’s hemolymph sheds light on the potential roles of co-existing endosymbionts
De Clerck, Caroline ULg; Fujiwara, Akiko; Joncour, Pauline et al

in Microbiome (2015), 3(63),

Background: Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory ... [more ▼]

Background: Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory symbiont present in aphids, supplying essential nutrients that are missing in the plants phloem to its host. Pentalonia nigronervosa is the main vector of the banana bunchy top virus, one of the most damageable viruses in banana. This aphid is carrying two symbionts: B. aphidicola (BPn) and Wolbachia sp. (wPn). The high occurrence of Wolbachia in the banana aphid raises questions about the role it plays in this insect. The goal of this study was to go further in the understanding of the role played by the two symbionts in P. nigronervosa. To do so, microinjection tests were made to see the effect of wPn elimination on the host, and then, high-throughput sequencing of the haemolymph was used to analyze the gene content of the symbionts. Results: We observed that the elimination of wPn systematically led to the death of aphids, suggesting that the bacterium could play a mutualistic role. In addition, we identify and annotate 587 and 250 genes for wPn and BPn, respectively, through high-throughput sequencing. Analysis of these genes suggests that the two bacteria are working together for the production of several essential nutrients. The most striking cases are for lysin and riboflavin which are usually provided by B. aphidicola alone to the host. In the banana aphid, the genes involved in the production pathways of these metabolites are shared between the two bacteria making them both essential for the survival of the aphid host. Conclusions: Our results suggest that a co-obligatory symbiosis between B. aphidicola and Wolbachia occurs in the banana aphid, the two bacteria acting together to supply essential nutrients to the host. This is, to our knowledge, the first time Wolbachia is reported to play an essential role in aphids. [less ▲]

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See detailEffects of Plant Growth-Promoting Rhizobacteria on Wheat Growth under Greenhouse and Field Conditions in combination with different nitrogen fertilizer levels
Nguyen, Minh ULg; Ongena, Marc ULg; Colinet, Gilles ULg et al

Poster (2015, November 23)

Many Plant Growth-Promoting Rhizobacteria (PGPR) are able to enhance root growth, mineral availability, and nutrient use efficiency of crops. The aim of this project is to screen commercially available ... [more ▼]

Many Plant Growth-Promoting Rhizobacteria (PGPR) are able to enhance root growth, mineral availability, and nutrient use efficiency of crops. The aim of this project is to screen commercially available PGPR formulations and lab strains to increase wheat growth and yield in combination with an optimized nitrogen (N) fertilizer application scheme. This could lead to a significant reduction of N fertilizer application without affecting the subsequent grain yields. The screened products collection includes (1) Mix1 (a mix of Azospirillum sp., Azorhizobium sp., and Azoarcus sp.), (2) Mix2 (a mix of Mix1 complemented with two strains of phosphorus-solubilizing Bacillus sp.), (3) Bacillus amyloliquefaciens a, (4) B. subtilis, and (5) B. amyloliquefaciens b. These products were screened under greenhouse and field conditions in 2014 by using spring and winter wheat varieties, respectively. Under greenhouse conditions, there was a significant increase in root dry weight and in root per shoot ratio of plants inoculated with Mix1. Under field conditions, the interaction between PGPR inoculation and different N fertilizer doses was assessed. The grain yield was negatively impacted by low N fertilizer applications. Under such conditions, the inoculation of the wheat rhizosphere with B. subtilis increased the grain yield by 15% relative to the water control. However, in the field trial, the variability between plot replicates was high and lead to non-significant results. Based on these results, modified screening strategies for PGPR selection were set up for the next trials. [less ▲]

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See detailImpacts of Plant Growth-Promoting Rhizobacteria-based Biostimulants on Wheat Growth under Greenhouse and Field Conditions
Nguyen, Minh ULg; Ongena, Marc ULg; Colinet, Gilles ULg et al

Poster (2015, November 16)

Plant Growth-Promoting Rhizobacteria (PGPR) are one of the main biostimulant classes due to their capacity of stimulating root growth and enhancing soil mineral availability, hence increasing nutrient use ... [more ▼]

Plant Growth-Promoting Rhizobacteria (PGPR) are one of the main biostimulant classes due to their capacity of stimulating root growth and enhancing soil mineral availability, hence increasing nutrient use efficiency in crops. The aim of this study is to screen commercially PGPR-containing products to enhance wheat growth and yield in combination with an optimized nitrogen (N) fertilizer application scheme. This could lead to a significant reduction of N fertilizer application without affecting the subsequent grain yields. The screened products collection includes (1) Mix1 (a mix of Azospirillum sp., Azorhizobium sp., and Azoarcus sp.), (2) Mix2 (a mix of Mix1 complemented with two strains of phosphorus-solubilizing Bacillus sp.), (3) Bacillus amyloliquefaciens a, (4) B. subtilis, and (5) B. amyloliquefaciens b. These biostimulants were screened under greenhouse and field conditions in 2014 by using spring and winter wheat varieties respectively. There was a significant increase in root dry weight and in root per shoot ratio of plants inoculated with Mix1. Under field conditions, the interaction between PGPR inoculation and N fertilizer application was assessed. The grain yield was negatively impacted by low N fertilizer applications. Under such conditions, the inoculation of the wheat rhizosphere with Bacillus subtilis increased the grain yield by 15% relative to the water control. However, in the field trial, the variability between plot replicates was high and lead to non-significant results. Based on those results, modified screening strategies for PGPR selection were set up for the 2015 trials to reduce field variability and possibly achieve higher yield increases. [less ▲]

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See detailElicitor screening to protect wheat against Zymoseptoria tritici
Le Mire, Géraldine ULg; SIAH, ALI; Deleu, Magali ULg et al

Conference (2015, August 27)

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 monocotyledonous 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). Topical spraying treatments with 3 different concentrations of each product were carried out 5 days before pathogen inoculation. Disease severity (% of symptoms on the total surface of the third leaf) was then scored every 2 days up to 28 days post-inoculation. In addition, phytotoxicity and biocide activity of these products was 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 ▲]

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See detailEffect of Volatile Organic Compounds against fungal and bacterial plant pathogens
Kaddes, Amine ULg; Massart, Sébastien ULg; Fauconnier, Marie-Laure ULg et al

Scientific conference (2015, August 25)

Barley is threatened by various edaphic fungal diseases. Common root rot, caused by Fusarium culmorum and Cochliobolus sativus , is one of the major fungal diseases of barley, causing between 9 and 23 ... [more ▼]

Barley is threatened by various edaphic fungal diseases. Common root rot, caused by Fusarium culmorum and Cochliobolus sativus , is one of the major fungal diseases of barley, causing between 9 and 23 % of yield losses. Since several chemicals used for crop protection are being forbidden, new ways of protection are needed. In a previous study, we have shown that barley roots infected by common root rot emitted 23 Volatile Organic Compounds (VOCs) that were not emitted by healthy barley roots. Among VOCs methyl propionate and methyl acrylate applied alone reduced significantly the development of both barley pathogens. The main objective of this study is to evaluate the antifungal and antibacterial activity of both VOCs on a wider range of plant pathogens: Fusarium culmorum , Fusarium graminiurum, Penicillium expansum, Penicilium digitatum and Penicilium itallicum as fungal pathogens ) and Pectobacterium carotovorum carotovorum and Pectobacterium atrosepticum as bacterial pathogens. The evaluation has been made through ELISA microplates with PDB or V8 media. The growth of the pathogen (bacteria and conidia) in the presence of the VOCs was evaluated and compared to a control (same media without VOCs). Methylpropionate showed interesting antibacterial activity with 40% and 96%of inhibition against Pectobacterium carotovorum carotovorum and Pectobacterium atrosepticum, respectively. An inhibition of 77 and 97 % was observed in presence of methylacrylate against Pectobacterium carotovorum carotovorum and Pectobacterium atrosepticum, respectively. Concerning antifungal activity, the results showed that the methyl acrylate inhibted the growth of all tested fungi (the least was P.digitatum by 70%), similarly to methylpropionate (with 50% found in F.culmorum). [less ▲]

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