CNRS Biomolecule and Plant Biotechnology Laboratory

Tours, France

CNRS Biomolecule and Plant Biotechnology Laboratory

Tours, France
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Lanoue A.,Jülich Research Center | Lanoue A.,CNRS Biomolecule and Plant Biotechnology Laboratory | Burlat V.,Jülich Research Center | Henkes G.J.,Jülich Research Center | And 3 more authors.
New Phytologist | Year: 2010

Despite recent advances in elucidation of natural products in root exudates, there are significant gaps in our understanding of the ecological significance of products in the rhizosphere. Here, we investigated the potential of barley (Hordeum vulgare) to secrete defense root exudates when challenged by the soilborne pathogen Fusarium graminearum. Liquid chromatography with photodiode array detection (LC-DAD) was used to profile induced small-molecular-weight exudates. Thus, t-cinnamic, p-coumaric, ferulic, syringic and vanillic acids were assigned to plant metabolism and were induced within 2 d after Fusarium inoculation. Biological tests demonstrated the ability of those induced root exudates to inhibit the germination of F. graminearum macroconidia. In vivo labeling experiments with 13CO2 revealed that the secreted t-cinnamic acid was synthesized de novo within 2 d of fungal infection. Simultaneously to its root exudation, t-cinnamic acid was accumulated in the roots. Microscopic analysis showed that nonlignin cell wall phenolics were induced not only in necrosed zones but in all root tissues. Results suggest that barley plants under attack respond by de novo biosynthesis and secretion of compounds with antimicrobial functions that may mediate natural disease resistance. © 2009 New Phytologist.

Cannesan M.A.,University of Rouen | Gangneux C.,Laboratoire BioSol | Lanoue A.,CNRS Biomolecule and Plant Biotechnology Laboratory | Giron D.,CNRS Research Institute of Insect Biology | And 4 more authors.
Annals of Botany | Year: 2011

•Background and Aims: The oomycete Aphanomyces euteiches causes up to 80% crop loss in pea (Pisum sativum). Aphanomyces euteiches invades the root system leading to a complete arrest of root growth and ultimately to plant death. To date, disease control measures are limited to crop rotation and no resistant pea lines are available. The present study aims to get a deeper understanding of the early oomyceteplant interaction at the tissue and cellular levels. •Methods: Here, the process of root infection by A. euteiches on pea is investigated using flow cytometry and microscopic techniques. Dynamic changes in secondary metabolism are analysed with high-performance liquid chromatography with diode-array detection. •Key Results: Root infection is initiated in the elongation zone but not in the root cap and border cells. Border-cell production is significantly enhanced in response to root inoculation with changes in their size and morphology. The stimulatory effect of A. euteiches on border-cell production is dependent on the number of oospores inoculated. Interestingly, border cells respond to pathogen challenge by increasing the synthesis of the phytoalexin pisatin. •Conclusions: Distinctive responses to A. euteiches inoculation occur at the root tissue level. The findings suggest that root border cells in pea are involved in local defence of the root tip against A. euteiches. Root border cells constitute a convenient quantitative model to measure the molecular and cellular basis of plantmicrobe interactions. © The Author 2011. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved.

Chapeland-Leclerc F.,University of Paris Descartes | Hennequin C.,Laboratoire Of Parasitologie Mycologie | Papon N.,CNRS Biomolecule and Plant Biotechnology Laboratory | Noel T.,University of Bordeaux Segalen | And 4 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2010

We describe the acquisition of flucytosine, azole, and caspofungin resistance in sequential Candida glabrata bloodstream isolates collected from a bone marrow transplant patient with clinical failure. Point mutations in C. glabrata FUR1 (CgFUR1) and CgFKS2 and overexpression of CgCDR1 and CgCDR2 were observed in resistant isolates. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Defosse T.A.,CNRS Biomolecule and Plant Biotechnology Laboratory | Sharma A.,Chandigarh Institute of Microbial Technology | Mondal A.K.,Chandigarh Institute of Microbial Technology | Mondal A.K.,Jawaharlal Nehru University | And 7 more authors.
Molecular Microbiology | Year: 2015

Histidine kinases (HK) sense and transduce via phosphorylation events many intra- and extracellular signals in bacteria, archaea, slime moulds and plants. HK are also widespread in the fungal kingdom, but their precise roles in the regulation of physiological processes remain largely obscure. Expanding genomic resources have recently given the opportunity to identify uncharacterised HK family members in yeasts and moulds and now allow proposing a complex classification of Basidiomycota, Ascomycota and lower fungi HK. A growing number of genetic approaches have progressively provided new insight into the role of several groups of HK in prominent fungal pathogens. In particular, a series of studies have revealed that members of group III HK, which occur in the highest number of fungal species and contain a unique N-terminus region consisting of multiple HAMP domain repeats, regulate morphogenesis and virulence in various human, plant and insect pathogenic fungi. This research field is further supported by recent shape-function studies providing clear correlation between structural properties and signalling states in group III HK. Since HK are absent in mammals, these represent interesting fungal target for the discovery of new antifungal drugs. Hybrid histidine kinases (HHK) are sensing proteins widespread in the fungal kingdom. We propose here an updated compilation and classification of fungal HHK with special focus in the most prominent pathogenic fungi. This analysis revealed that a particular group of fungal HHK, namely group III HHK, remains the most conserved among fungal pathogens of human, plant and insect. © 2015 John Wiley & Sons Ltd.

Giron D.,CNRS Research Institute of Insect Biology | Glevarec G.,CNRS Biomolecule and Plant Biotechnology Laboratory
Journal of Chemical Ecology | Year: 2014

Recently, a renewed interest in cytokinins (CKs) has allowed the characterization of these phytohormones as key regulatory molecules in plant biotic interactions. They have been proved to be instrumental in microbe- and insect-mediated plant phenotypes that can be either beneficial or detrimental for the host-plant. In parallel, insect endosymbiotic bacteria have emerged as key players in plant-insect interactions mediating directly or indirectly fundamental aspects of insect nutrition, such as insect feeding efficiency or the ability to manipulate plant physiology to overcome food nutritional imbalances. However, mechanisms that regulate CK production and the role played by insects and their endosymbionts remain largely unknown. Against this backdrop, studies on plant-associated bacteria have revealed fascinating and complex molecular mechanisms that lead to the production of bacterial CKs and the modulation of plant-borne CKs which ultimately result in profound metabolic and morphological plant modifications. This review highlights major strategies used by plant-associated bacteria that impact the CK homeostasis of their host-plant, to raise parallels with strategies used by phytophagous insects and to discuss the possible role played by endosymbiotic bacteria in these CK-mediated plant phenotypes. We hypothesize that insects employ a CK-mix production strategy that manipulates the phytohormonal balance of their host-plant and overtakes plant gene expression causing a metabolic and morphological habitat modification. In addition, insect endosymbiotic bacteria may prove to be instrumental in these manipulations through the production of bacterial CKs, including specific forms that challenge the CK-degrading capacity of the plant (thus ensuring persistent effects) and the CK-mediated plant defenses. © 2014 Springer Science+Business Media New York.

Giron D.,CNRS Research Institute of Insect Biology | Frago E.,University of Oxford | Glevarec G.,CNRS Biomolecule and Plant Biotechnology Laboratory | Pieterse C.M.J.,University Utrecht | Dicke M.,Wageningen University
Functional Ecology | Year: 2013

Plant hormones play important roles in regulating plant growth and defence by mediating developmental processes and signalling networks involved in plant responses to a wide range of parasitic and mutualistic biotic interactions. Plants are known to rapidly respond to pathogen and herbivore attack by reconfiguring their metabolism to reduce pathogen/herbivore food acquisition. This involves the production of defensive plant secondary compounds, but also an alteration of the plant primary metabolism to fuel the energetic requirements of the direct defence. Cytokinins are plant hormones that play a key role in plant morphology, plant defence, leaf senescence and source-sink relationships. They are involved in numerous plant-biotic interactions. These phytohormones may have been the target of arthropods and pathogens over the course of the evolutionary arms race between plants and their biotic partners to hijack the plant metabolism, control its physiology and/or morphology and successfully invade the plant. In the case of arthropods, cytokinin-induced phenotypes can be mediated by their bacterial symbionts, giving rise to intricate plant-microbe-insect interactions. Cytokinin-mediated effects strongly impact not only plant growth and defence but also the whole community of insect and pathogen species sharing the same plant by facilitating or preventing plant invasion. This suggests that cytokinins (CKs) are key regulators of the plant growth-defence trade-off and highlights the complexity of the finely balanced responses that plants use while facing both invaders and mutualists. © 2013 The Authors. Functional Ecology © 2013 British Ecological Society.

Jousset A.,University of Gottingen | Rochat L.,University of Lausanne | Lanoue A.,CNRS Biomolecule and Plant Biotechnology Laboratory | Bonkowski M.,University of Cologne | And 2 more authors.
Molecular Plant-Microbe Interactions | Year: 2011

Plant health and fitness widely depend on interactions with soil microorganisms. Some bacteria such as pseudomonads can inhibit pathogens by producing antibiotics, and controlling these bacteria could help improve plant fitness. In the present study, we tested whether plants induce changes in the antifungal activity of root-associated bacteria as a response to root pathogens. We grew barley plants in a split-root system with one side of the root system challenged by the pathogen Pythium ultimum and the other side inoculated with the biocontrol strain Pseudomonas fluorescens CHA0. We used reporter genes to follow the expression of ribosomal RNA indicative of the metabolic state and of the gene phlA, required for production of 2,4-diacetylphloroglucinol, a key component of antifungal activity. Infection increased the expression of the antifungal gene phlA. No contact with the pathogen was required, indicating that barley influenced gene expression by the bacteria in a systemic way. This effect relied on increased exudation of diffusible molecules increasing phlA expression, suggesting that communication with rhizosphere bacteria is part of the pathogen response of plants. Tripartite interactions among plants, pathogens, and bacteria appear as a novel determinant of plant response to root pathogens. © 2011 The American Phytopathological Society.

Simkin A.J.,CNRS Biomolecule and Plant Biotechnology Laboratory | Guirimand G.,CNRS Biomolecule and Plant Biotechnology Laboratory | Papon N.,CNRS Biomolecule and Plant Biotechnology Laboratory | Courdavault V.,CNRS Biomolecule and Plant Biotechnology Laboratory | And 6 more authors.
Planta | Year: 2011

In plants, the mevalonic acid (MVA) pathway provides precursors for the formation of triterpenes, sesquiterpenes, phytosterols and primary metabolites important for cell integrity. Here, we have cloned the cDNA encoding enzymes catalysing the final three steps of the MVA pathway from Madagascar periwinkle (Catharanthus roseus), mevalonate kinase (MVK), 5-phosphomevalonate kinase (PMK) and mevalonate 5-diphosphate decarboxylase (MVD). These cDNA were shown to functionally complement MVA pathway deletion mutants in the yeast Saccharomyces cerevisiae. Transient transformations of C. roseus cells with yellow fluorescent protein (YFP)-fused constructs reveal that PMK and MVD are localised to the peroxisomes, while MVK was cytosolic. These compartmentalisation results were confirmed using the Arabidopsis thaliana MVK, PMK and MVD sequences fused to YFP. Based on these observations and the arguments raised here we conclude that the final steps of the plant MVA pathway are localised to the peroxisome. © 2011 Springer-Verlag.

Zhang H.,Leiden University | Hedhili S.,CNRS Biomolecule and Plant Biotechnology Laboratory | Montiel G.,CNRS Biomolecule and Plant Biotechnology Laboratory | Zhang Y.,Leiden University | And 6 more authors.
Plant Journal | Year: 2011

Jasmonates are plant signalling molecules that play key roles in defence against insects and certain pathogens, among others by controlling the biosynthesis of protective secondary metabolites. In Catharanthus roseus, the AP2/ERF-domain transcription factor ORCA3 controls the jasmonate-responsive expression of several genes encoding enzymes involved in terpenoid indole alkaloid biosynthesis. ORCA3 gene expression is itself induced by jasmonate. The ORCA3 promoter contains an autonomous jasmonate-responsive element (JRE) composed of a quantitative sequence responsible for the high level of expression and a qualitative sequence that acts as an on/off switch in response to methyl-jasmonate (MeJA). Here, we identify the basic helix-loop-helix (bHLH) transcription factor CrMYC2 as the major activator of MeJA-responsive ORCA3 gene expression. The CrMYC2 gene is an immediate-early jasmonate-responsive gene. CrMYC2 binds to the qualitative sequence in the ORCA3 JRE in vitro, and transactivates reporter gene expression via this sequence in transient assays. Knock-down of the CrMYC2 expression level via RNA interference caused a strong reduction in the level of MeJA-responsive ORCA3 mRNA accumulation. In addition, MeJA-responsive expression of the related transcription factor gene ORCA2 was significantly reduced. Our results show that MeJA-responsive expression of alkaloid biosynthesis genes in C. roseus is controlled by a transcription factor cascade consisting of the bHLH protein CrMYC2 regulating ORCA gene expression, and the AP2/ERF-domain transcription factors ORCA2 and ORCA3, which in turn regulate a subset of alkaloid biosynthesis genes. © 2011 Blackwell Publishing Ltd.

Papon N.,CNRS Biomolecule and Plant Biotechnology Laboratory | Courdavault V.,CNRS Biomolecule and Plant Biotechnology Laboratory | Clastre M.,CNRS Biomolecule and Plant Biotechnology Laboratory
Trends in Biotechnology | Year: 2014

Some of the fungal CTG clade species represent attractive yeast models in many aspects of biotechnology. Their particular codon usage has hindered the development of genetic approaches for exploring and exploiting their biotechnological potential. CTG clade yeast biotechnology now benefits from the establishment of versatile molecular toolboxes. In addition, a large range of rapidly evolving genomic and postgenomic approaches has recently enhanced the understanding of the architecture of CTG species metabolic networks. These represent essential prerequisites for further successful development of metabolic engineering in CTG yeasts by facilitating the design of synthetic pathways. © 2013 Elsevier Ltd.

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