References of "Ongena, MARC"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailMolecular patterns of rhizobacteria involved in plant immunity elicitation.
Mariutto, Martin ULg; Ongena, Marc ULg

in Advances in Botanical Research (in press)

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailCharacterization of Cichopeptins, New Phytotoxic Cyclic Lipodepsipeptides Produced by Pseudomonas cichorii SF1-54, and Their Role in Bacterial Midrib Rot Disease of Lettuce
Huang, CJ; Pauwelyn, E.; Ongena, Marc ULg et al

in Molecular Plant-Microbe Interactions [=MPMI] (in press)

Detailed reference viewed: 13 (0 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: 29 (13 ULg)
See detailSurfactin: a receptor-independent bacterial elicitor of plant immunity?
Luzuriaga Loaiza, Walter ULg; Legras, Aurelien; Crowet, Jean-Marc ULg et al

Scientific conference (2015, May 13)

Detailed reference viewed: 18 (2 ULg)
Full Text
Peer Reviewed
See detailPlant polysaccharides initiate underground crosstalk with bacilli by inducing synthesis of the immunogenic lipopeptide surfactin
Debois, Delphine ULg; Fernandez, O.; Franzil, Laurent ULg et al

in Environmental Microbiology Reports (2015), 7(3), 570-582

Some plant-associated bacteria such as Bacillus sp. can protect their host from pathogen ingress and this biocontrol activity correlates with their potential to form multiple antibiotics upon in vitro ... [more ▼]

Some plant-associated bacteria such as Bacillus sp. can protect their host from pathogen ingress and this biocontrol activity correlates with their potential to form multiple antibiotics upon in vitro growth. However, our knowledge on antibiotic production by soil bacilli evolving on roots in natural conditions is still limited. In this work, antibiome imaging first revealed that the lipopeptide surfactin is the main bacterial ingredient produced in planta within the first hours of interaction with root tissues. We further demonstrated that surfactin synthesis is specifically stimulated upon perception of plant cell wall polymers such as xylan or arabinogalactan, leading to fast accumulation of micromolar amounts in the root environment. At such concentrations, the lipopeptide may not only favour the ecological fitness of the producing strain in term of root colonization, but also triggers systemic resistance in the host plant. This surfactin-induced immunity primes the plant to better resist further pathogen ingress, and involves only limited expression of defence-related molecular events and does not provoke seedling growth inhibition. By contrast with the strong response mounted upon perception of pathogens, this strongly attenuated defensive reaction induced by surfactin in plant tissues should help Bacillus to be tolerated as saprophytic partner by its host. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd. [less ▲]

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailLipopeptides as main ingredients for inhibition of fungal phytopathogens by Bacillus subtilis/amyloliquefaciens
Cawoy, H.; Debois, Delphine ULg; Franzil, Laurent ULg et al

in Microbial Biotechnology (2015), 8(2), 281-295

Summary: Some isolates of the Bacillus subtilis/amyloliquefaciens species are known for their plant protective activity against fungal phytopathogens. It is notably due to their genetic potential to form ... [more ▼]

Summary: Some isolates of the Bacillus subtilis/amyloliquefaciens species are known for their plant protective activity against fungal phytopathogens. It is notably due to their genetic potential to form an impressive array of antibiotics including non-ribosomal lipopeptides (LPs). In the work presented here, we wanted to gain further insights into the relative role of these LPs in the global antifungal activity of B.subtilis/amyloliquefaciens. To that end, a comparative study was conducted involving multiple strains that were tested against four different phytopathogens. We combined various approaches to further exemplify that secretion of those LPs is a crucial trait in direct pathogen ward off and this can actually be generalized to all members of these species. Our data illustrate that for each LP family, the fungitoxic activity varies in function of the target species and that the production of iturins and fengycins is modulated by the presence of pathogens. Our data on the relative involvement of these LPs in the biocontrol activity and modulation of their production are discussed in the context of natural conditions in the rhizosphere. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology. [less ▲]

Detailed reference viewed: 10 (0 ULg)
See detailPGPR elicitors of plant immunity: insights into the molecular basis of surfactin perception
Luzuriaga Loaiza, Walter ULg; Legras, Aurélien; Franzil, Laurent ULg et al

Scientific conference (2015)

Detailed reference viewed: 20 (0 ULg)
See detailBiopesticides: quand les biotechs se mettent au service d’une agriculture durable
Zune, Quentin ULg; Ongena, Marc ULg

Scientific conference (2014, December 10)

Présentation des différents outils de la biotechnologie (Omics et bioprocédés) pour mieux comprendre le fonctionnement des biopesticides microbiens afin d'améliorer leur efficacité lors de leurs ... [more ▼]

Présentation des différents outils de la biotechnologie (Omics et bioprocédés) pour mieux comprendre le fonctionnement des biopesticides microbiens afin d'améliorer leur efficacité lors de leurs applications sur les cultures. [less ▲]

Detailed reference viewed: 24 (1 ULg)
See detailScreening of elicitor candidates on winter wheat against Septoria tritici
Le Mire, Géraldine ULg; Deleu, Magali ULg; Ongena, Marc ULg et al

Scientific conference (2014, October 14)

The various experiments to be held prior to elicitor screening are detailed, along with the screening metholodogy. Explanation is given on the increasing interests of plant elicitors, or "stimulators of ... [more ▼]

The various experiments to be held prior to elicitor screening are detailed, along with the screening metholodogy. Explanation is given on the increasing interests of plant elicitors, or "stimulators of natural defenses", for the sustainability of our agro-ecosystems. [less ▲]

Detailed reference viewed: 43 (12 ULg)
Full Text
See detailElicitor screening to protect winter wheat against Septoria tritici Blotch: preliminary results
Le Mire, Géraldine ULg; Deleu, Magali ULg; Ongena, Marc ULg et al

Conference (2014, September)

Elicitors are plant immunity-triggering compounds which are currently considered as one of the most promising tools in agriculture for the induction of plant resistance to various diseases (Mejía-Teniente ... [more ▼]

Elicitors are plant immunity-triggering compounds which are currently considered as one of the most promising tools in agriculture for the induction of plant resistance to various diseases (Mejía-Teniente et al., 2010). By contributing to both economic and environmental performances of agroecosystems, they can help reducing the use of chemical inputs. Although some elicitor products are already available on the market, it appears that a variable efficiency in the field, along with an uneasy integration in the current legislation and agricultural strategies, make these tools difficult to use (Walters, Ratsep, & Havis, 2013). Besides these limitations, few elicitor treatments have yet been efficiently and specifically designed to protect crop plants such as wheat, which is grown and consumed worldwide, against major diseases threatening both their yield and quality. There is a strong need to better understand the mechanisms of induced resistance in plants and develop elicitor use in agriculture. A phD research is currently led in Gembloux Agro Bio-Tech to develop a method based on eliciting agents, tested in greenhouse and field conditions, to protect winter wheat against major diseases, namely Septoria tritici, Fusarium graminearum and Fusarium culmorum. This project focuses on the screening of a large number of elicitors from different origins and structures. In 2014, we focused the first screening experiments on the protection of wheat against Septoria tritici Blotch (STB). Two winter wheat genotypes were tested: susceptible ‘Avatar’ and semi-resistant ‘Sy Epson’. Plants at 3-leaf stage were first sprayed till runoff with different concentrations of elicitors, and then inoculated 5 days later with a Septoria tritici spore suspension (106 spores mL-1) using a hand sprayer. Control plants were treated, prior to disease inoculation, with sterile water (negative control) or with BION® (ASM, Syngenta Europe; positive control). The disease severity and incidence were scored every 2 days for 28 days post-inoculation (d.p.i) by measuring the percentage of area covered with lesions and bearing pycnidia on the third leaf. The first results of these tests should enable a first discrimination of elicitors considering their dose-efficiency to reduce disease severity. After further screening of all the elicitors in hand, a determination of the elicitation pathways of the most efficient molecules tested will be undertaken. We intend to study the influence of various factors (i.e Temperature, relative humidity, plant development stage) on the elicitation potential and develop a formulation to be finally tested under field conditions. [less ▲]

Detailed reference viewed: 64 (11 ULg)
Full Text
Peer Reviewed
See detailMALDI Mass Spectrometry Imaging: a new tool to decipher the antibiome of Bacillus amyloliquefaciens
Debois, Delphine ULg; Jourdan, Emmanuel; Cawoy, Hélène et al

Conference (2014, June 05)

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known ... [more ▼]

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known to exert different actions on the wellness of the producing strain such as fungitoxicity (iturin, fengycin) or motility, root colonization and immune stimulating agent (surfactin). Nevertheless, few is reported about the actual antibiome secreted in situ by Bacillus cells during confrontation with phytopathogens or plant root colonization. We developed a method mimicking the conditions prevailing in the rhizosphere and, taking advantage of the versatility of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging, we were able to localize and identify antibiotics produced in situ by bacterial cells. First, we applied this new methodology to bioassays in which Bacillus amyloliquefaciens 98S were grown together with Fusarium oxysporum, with the aim of deciphering the role of the different LP families during the phytopathogen growth inhibition. Our results showed that the three LP families were readily produced in different proportions. Especially, images of surfactins, iturins and fengycins demonstrated that iturins are the antibiotic family actually involved in the antagonism against Fusarium oxysporum. In a second approach, we used a “in planta” model in which Bacillus amyloliquefaciens S499 was simultaneously grown with Tomato and Arabidopsis thaliana roots. Imaging results, obtained during a time course analysis, showed that surfactin is always the major lipopeptide detected. In further experiments involving a refined time-window, we observed that surfactin is actually produced as soon as 24h post inoculation. These results were the starting point of a wider study showing that the early accumulation of surfactin is a complex phenomenon involving, among other mechanisms, cell-well components recognition by bacteria, and that this interaction is a win-win association for both plant and bacterial cells. [less ▲]

Detailed reference viewed: 109 (7 ULg)
Full Text
See detailA methodology for elicitor screening of winter wheat infected by STB and FHB
Le Mire, Géraldine ULg; SIAH, Ali; Deleu, Magali ULg et al

Poster (2014, May 20)

Un doctorat au sein de Gembloux Agro Bio-Tech (Plateforme Agriculture Is Life) vise à développer une méthode à base d'éliciteurs bio-sourcés pour protéger le blé d'hivers contre la Septoriose (STB) et la ... [more ▼]

Un doctorat au sein de Gembloux Agro Bio-Tech (Plateforme Agriculture Is Life) vise à développer une méthode à base d'éliciteurs bio-sourcés pour protéger le blé d'hivers contre la Septoriose (STB) et la Fusariose (FHB). Dans ce cadre, la mise au point d'un protocole efficace d'infection du blé est élémentaire avant de pouvoir entamer les tests de screening d'éliciteurs. Nous présentons ici une méthode d'infection du blé par Septoria tritici et les résultats de ces tests de reproduction de symptômes. [less ▲]

Detailed reference viewed: 54 (15 ULg)
Full Text
Peer Reviewed
See detailSpatiotemporal monitoring of the antibiome secreted by Bacillus biofilms on plant roots using MALDI mass spectrometry imaging
Debois, Delphine ULg; Jourdan, Emmanuel; Smargiasso, Nicolas ULg et al

in Analytical Chemistry (2014), 86(9), 4431-4438

Some soil Bacilli living in association with plant roots can protect their host from infection by pathogenic microbes and are therefore being developed as biological agents to control plant diseases. The ... [more ▼]

Some soil Bacilli living in association with plant roots can protect their host from infection by pathogenic microbes and are therefore being developed as biological agents to control plant diseases. The plant protective activity of these bacteria has been correlated with the potential to secrete a wide array of antibiotic compounds upon growth as planktonic cells in isolated cultures under laboratory conditions. However, in situ expression of these antibiotics in the rhizosphere where bacterial cells naturally colonize root tissues is still poorly understood. In this work, we used Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI MSI) to examine spatio-temporal changes in the secreted antibiome of B. amyloliquefaciens developing as biofilms on roots. Non-ribosomal lipopeptides such as the plant immunity elicitor surfactin or the highly fungitoxic iturins and fengycins were readily produced albeit in different time-frames and quantities in the surrounding medium. Interestingly, MS/MS experiments performed directly from the gelified culture medium, also allowed to identify a new variant of surfactins released at later time points. However, no other bioactive compounds such as polyketides were detected at any time, strongly suggesting that the antibiome expressed in planta by B. amyloliquefaciens does not reflect the vast genetic arsenal devoted to the formation of such compounds. This first dynamic study reveals the power of MALDI MSI as tool to identify and map antibiotics synthesized by root-associated bacteria and more generally, to investigate plant-microbe interactions at the molecular level. [less ▲]

Detailed reference viewed: 71 (7 ULg)
Full Text
Peer Reviewed
See detailAltered Desferrioxamine-mediated Iron Utilization is a Common Trait of bald Mutants of Streptomyces coelicolor
Lambert, Stéphany ULg; Traxler, Matthew F; Craig, Matthias et al

in Metallomics (2014)

Detailed reference viewed: 52 (23 ULg)
Full Text
See detailImaging MS: strategies for the identification of analytes
Debois, Delphine ULg; Smargiasso, Nicolas ULg; Jourdan, Emmanuel et al

Scientific conference (2014, April 04)

Detailed reference viewed: 41 (6 ULg)