Symbiosis-related plant genes modulate molecular responses in an arbuscular mycorrhizal fungus during early root interactions

International audience

TheMedicago truncatulahypermycorrhizal B9 mutant displays an altered response to phosphate and is more susceptible toAphanomyces euteiches

Inorganic phosphate (Pi) plays a key role in the development of arbuscular mycorrhizal (AM) symbiosis, which is favoured when Pi is limiting in the environment. We have characterized the Medicago truncatula hypermycorrhizal B9 mutant for its response to limiting (P/10) and replete (P2) Pi. On P2, mycorrhization was significantly higher in B9 plants than in wild-type (WT). The B9 mutant displayed hallmarks of Pi-limited plants, including higher levels of anthocyanins and lower concentrations of Pi in shoots than WT plants. Transcriptome analyses of roots of WT and B9 plants cultivated on P2 or on P/10 confirmed the Pi-limited profile of the mutant on P2 and highlighted its altered response t…

Signposting compatibility events driving the mycorrhizal route

International audience

Developmental regulation of fungal-plant cross talk in arbuscular mycorrhiza

International audience

Coopération entre des bactéries solubilisatrices de phosphate et le champignon mycorhizien à arbuscule Rhizophagus irregularis dans la nutrition phosphatée de la pomme de terre

National audience; Le phosphore est un élément essentiel pour le développement des plantes. Néanmoins, la majorité des ions phosphate est incorporée dans des structures organiques (Po) et inorganiques (Pi) insolubles qui rende cet élément très peu disponible pour les plantes et en particulier pour la pomme de terre (Solanum tuberosum). Dans les sols, le phytate (molécule de réserve phosphatée des plantes), est une source essentielle. Pour accéder au phosphate, les plantes ont développé des symbioses mutualistes à bénéfices réciproques avec des microorganismes de la rhizosphère capables d’extraire le P. Dans ce contexte, les objectifs de cette étude étaient de i) déterminer si la disponibili…

Molecular detection of arbuscular mycorrhizal fungi: what are the challenges?

International audience

Calmodulin-stimulated cyclic nucleotide phosphodiesterase from Neurospora crassa.

International audience

Biologie des communautés dans la rhizosphère : analyse des interactions plantes - champignons mycorhizogènes à arbuscules - bactéries

National audience

Avis de l'Anses relatif à une demande d'évaluation de 4 substances naturelles à usage biostimulant : le saule, la prêle des champs, l’huile essentielle de menthe des champs et la léonardite.

Les substances naturelles à usage biostimulant (SNUB) sont définies dans le cadre de la réglementation applicable au niveau national. Conformément au point 4° de l'article L. 255-5 du code rural et de la pêche maritime, les SNUB sont dispensées d'une autorisation de mise sur le marché. Toutefois, elles sont soumises à une procédure d’autorisation et d’évaluation, dont les modalités sont fixées par voieréglementaire et codifiées à l'article D. 255-30-11 du code rural et de la pêche maritime.Ainsi, une SNUB est autorisée, le cas échéant avec des prescriptions particulières d’utilisation, par son inscription sur une liste annexée à l'arrêté du 27 avril 20162 et publiée par arrêté du ministre c…

Des facteurs de transcription fongiques impliqués dans l’établissement de la symbiose mycorhizienne à arbuscules

National audience

Construction and validation of cDNA-based Mt6k-RIT macro- and microarrays to explore root endosymbioses in the model legume Medicago truncatula

To construct macro- and microarray tools suitable for expression profiling in root endosymbioses of the model legume Medicago truncatula, we PCR-amplified a total of 6048 cDNA probes representing genes expressed in uninfected roots, mycorrhizal roots and young root nodules [Nucleic Acids Res. 30 (2002) 5579]. Including additional probes for either tissue-specific or constitutively expressed control genes, 5651 successfully amplified gene-specific probes were used to grid macro- and to spot microarrays designated Mt6k-RIT (M. truncatula 6k root interaction transcriptome). Subsequent to a technical validation of microarray printing, we performed two pilot expression profiling experiments usin…

Immunopurification of highly specific antibodies against calmodulin from Neurospora crassa

International audience

Molecular data challenging mycorrhizal taxonomy

Journée de formation pratique à l’observation des mycorhizes pour un groupe d’agriculteurs organisée par la Chambre d'Agriculture 46. Pôle Viticole d'Anglars-Juillac

Prod 2018-80pôle SPEIPMINRAUB; Journée de formation pratique à l’observation des mycorhizes pour un groupe d’agriculteurs organisée par la Chambre d'Agriculture 46. Pôle Viticole d'Anglars-Juillac. Journée de formation pratique à l’observation des mycorhizes pour un groupe d’agriculteurs

Developmental-regulated plant and fungal gene expression in mycorrhizal interactions with compatible and incompatible Medicago truncatula genotypes

International audience

Monitoring AM fungi activity of pionnier plants colonizing spoil banks after brown-coal mining

International audience

Ribosomal sequences as a tool to study and monitor arbuscular mycorrhizal fungi

International audience

The Medicago truncatula sucrose transporter family: characterization and implication of key members in carbon partitioning towards arbuscular mycorrhizal fungi.

We identified de novo sucrose transporter (SUT) genes involved in long-distance transport of sucrose from photosynthetic source leaves towards sink organs in the model leguminous species Medicago truncatula. The iden- tification and functional analysis of sugar transporters provide key information on mechanisms that underlie carbon partitioning in plant-microorganism interactions. In that way, full-length sequences of the M. truncatula SUT (MtSUT) family were retrieved and biochemical characterization of MtSUT members was performed by heterologous expression in yeast. The MtSUT family now comprises six genes which distribute among Dicotyledonous clades. MtSUT1-1 and MtSUT4-1 are key members…

Calcium, calmodulin-dependent protein phosphorylation in Neurospora crassa

Abstract A calcium, calmodulin-dependent protein kinase activity has been partially purified by calmodulin-Sepharose affinity chromatography from the soluble fraction of Neurospora crassa . The phosphorylated peptide has an apparent molecular mass on SDS-polyacrylamide gel of 47 kDa. The apparent half maximal phosphorylation is obtained after 1.5 min at 30° C in the presence of calcium and calmodulin. The apparent half maximal activation of the phosphorylation is obtained at 1 μM calcium, and 0.1 or 0.2 μM calmodulin from bovine brain or Neurospora , respectively. The 32 P incorporation is enhanced about 10-fold by calmodulin.

Deciphering the molecular dialogue between arbuscular mycorrhizal partners during early root interactions

International audience

Influence of arbuscular mycorrhizal colonisation on cadmium induced Medicago truncatula root isoflavonoid accumulation.

Cadmium is a serious environmental pollution threats to the planet. Its accumulation in plants affects many cellular functions, resulting in growth and development inhibition, whose mechanisms are not fully understood. However, some fungi forming arbuscular mycorrhizal symbiosis with the majority of plant species have the capacity to buffer the deleterious effect of this heavy metal. In the present work we investigated the capacity of Rhizophagus irregularis (syn. Glomus irregularis) to alleviate cadmium stress in Medicago truncatula. In spite of a reduction in all mycorrhizal parameters, plants colonized for 21 days by R. irregularis and treated by 2 mg kg(-1) cadmium displayed less growth…

Mycorhization et viticulture

Prod 2017-372 SPE IPM INRA UB; National audience

Proteome analysis and identification of symbiosis-related proteins from Medicago truncatula Gaertn. by two-dimensional electrophoresis and mass spectrometry.

Time-course analysis of root protein profiles was studied by two-dimensional gel electrophoresis and silver staining in the model plant Medicago truncatula, inoculated either with the arbuscular mycorrhizal fungus Glomus mosseae or with the nitrogen fixing bacterium Sinorhizobium meliloti. Protein modifications in relation to the development of both symbioses included down- and upregulations, as well as newly induced polypeptides. Matrix assisted laser desorption/ionization-time of flight-mass spectrometry after trypsin digestion clearly identified one polypeptide induced in nodulated roots as a M. truncatula leghemoglobin. Internal sequencing with a quadrupole time-of-flight mass spectrome…

Local and systemic mycorrhiza-induced protection against the ectoparasitic nematode Xiphinema index involves priming of defence gene responses in grapevine

International audience; The ectoparasitic dagger nematode (Xiphinema index), vector of Grapevine fanleaf virus (GFLV), provokes gall formation and can cause severe damage to the root system of grapevines. Mycorrhiza formation by Glomus (syn. Rhizophagus) intraradices BEG141 reduced both gall formation on roots of the grapevine rootstock SO4 (Vitis berlandierixV. riparia) and nematode number in the surrounding soil. Suppressive effects increased with time and were greater when the nematode was post-inoculated rather than co-inoculated with the arbuscular mycorrhizal (AM) fungus. Using a split-root system, decreased X. index development was shown in mycorrhizal and non-mycorrhizal parts of my…

«Les mycorhizes au service des cultures». Rôle des mycorhizes et leviers agro-écologique pour les favoriser

«LES MYCORHIZES AU SERVICE DES CULTURES » Rôle des mycorhizes et leviers agro-écologique pour les favoriser. Dans le cadre du projet Mycoagra nous vous invitons le : Mardi 22 Mai de 15 h à 18 h Lycée Agricole du Périgord Avenue Winston Churchil Coulounieix Avec : Daniel WIPF - Diederick VAN TUINEN Pierre Emmanuel COURTY de l Université de Bourgogne et de l INRA Dijon Bourgogne Franche Comté, spécialistes des mycorhizes à arbuscules et plus particulièrement des réseaux endomycorhiziens "Conférence du Prof. Daniel Wipf sur le rôle et l' importance pour les plantes et les cultures des réseaux mycorihiziens et des leviers agro-écologiques pour favoriser leur développement "Observation sur lames…

Mycorrhizal fungal population structure in the field

Plant gene responses to Glomus mosseae in compatible and incompatible genotypes of Medicago truncatula

International audience

Arbuscular mycorrhizal symbiosis a new biotechnology for the development of sustainable agriculture

International audience

Mycorhization et viticulture : État des lieux et services écosystémiques rendus au vignoble

Prod 2017-371 SPE IPM INRA UB; National audience

Developmental-regulated gene expression in mycorrhizal interactions with host and non host Medicago truncatula

International audience

Medicago truncatula gene responses specific to arbuscular mycorrhiza interactions

International audience

Expression communes de gènes de M. truncatula lors de la mycorhization, la nodulation et l'interaction avec une rhizobactérie bénéfique

National audience

Molecular detection of arbuscular mycorrhizal fungi

International audience

Impact of tillage system on arbuscular mycorrhiza fungal communities in the soil under Mediterranean conditions.

A more diverse arbuscular mycorrhiza (AM) fungal community should be more versatile and resilient to variation in environmental conditions over space and time. To evaluate the effect of no-till and conventional tillage systems, AM fungal diversity was assessed as part of a long term field experiment by sequencing of DNA, extracted from soil, that encoded the large ribosomal sub-unit and was obtained by nested-PCR. In comparison with no-till, conventional tillage decreased AM fungal diversity by 40%. Differences between treatments in the frequency of the operational taxonomic units (OTUs) present in soil, confirm that AM fungi are differently vulnerable to soil disturbance.

The arbuscular mycorrhizal transportome, what next!

International audience; Understanding how arbuscular mycorrhizal (AM) symbioses establish and function is one of the most important current challenges in microbial ecology. Despite the fact that the AM symbiosis requires some complex and fine molecular tuning among symbionts in order to take place, both partners benefit from each other in a number of ways. For instance, the availability, uptake and exchange of nutrients in this biotrophic interaction are key factors driving plant growth and modulating biomass allocation. This underground trade is regulated by both plant and fungal transport components [1], as for instance the long distance transport of photosynthates from leaves towards col…

Arbuscular mycorrhizal fungi, partners of the rhizostabilization proccess of an orphan mining site

Common gene expression in Medicago truncatula roots in response to Pseudomonas fluorescens colonization, mycorrhiza development and nodulation

International audience

Arbuscular mycorrhizal symbiosis: a key actor in the soil for water quality preservation processes

National audience

Studies of root colonization by a microcosm community of arbuscular mycorrhizal fungi unsing nested PCR

International audience

The role of the plant genome in modulating arbuscular mycorrhizal formation.

International audience

Exploiting Glomus intraradices sequencing data to dissect molecular mechanisms of plant genome control over fungal gene expression in mycorrhiza

International audience

Molecular probes for studying population dynamics of arbuscular mycorrhizal fungi in roots and soil

International audience

Les mycorhizes à arbuscules, technologie pour l'amélioration de la production végétale

International audience

Les couverts végétaux. Un atout majeur pour réduire les intrants de synthèse et augmenter les services écosystémiques au vignoble

International audience; De manière générale, un couvert végétal se définit par une espèce ou une communauté d’espèces végétales recouvrant le sol de manière permanente ou temporaire. L’agriculteur a la possibilité de semer ces couverts, selon un choix raisonné, ou bien de laisser la végétation spontanée se développer. Il existe 3 types de couverts semés avec des objectifs différents pour l’exploitant : le couvert hivernal, installé pour faire face au phénomène d’érosion du sol important pendant cette période de repos végétatif ; les engrais verts, installés avec l’objectif d’amender naturellement la parcelle, en détruisant et en enfouissant les résidus du couvert qui libèrent ainsi de la ma…

High-troughput TILLING to identify symbiosis-related plant gene function in arbuscular mycorrhiza

International audience

Role of a transcription factor, GintSTE, from Glomus intraradices in the establishment of arbuscular mycorrhizal

International audience

Diversity of arbuscular mycorrhizal fungi (Glomeromycota) in european soils analysed by pyrosequencing

Arbuscular mycorrhiza provides essential ecosystem functions in natural and humandominated ecosystems. Generally human activities like agriculture seem to have a negative effect on diversity of arbuscular mycorrhizal fungi (AMF), and thus on ecosystem functioning. New sequencing technologies now allow to assess AMF diversity on a much larger scale than previously. In the context of the European project EcoFINDERS, five Long-Term Observatories across Europe with different soil management have been studied. The diversity of AMF in these soils is analyzed by pyrosequencing, using the ITS (rDNA Internal Transcribed Spacers) as marker, which were recently determined as the standard barcoding gen…

Can LCO and mycorrhiza mitigate the impact of water deficit on pea growth in co-inoculations with rhizobium? A preliminary assessment

National audience; Water stress is a major factor limiting production of legumes in Europe, but could be mitigated by improving interactions between plant roots and soil microbial communities, including symbiotic rhizobia and arbuscular mycorrhizal fungi. These two microbes produce lipochitooligosaccharide (LCO) signals, which stimulate symbiotic interactions and lateral root formation [1, 2]. While N2-fixation by rhizobia fulfills the plants N requirement [3], mycorrhizal fungi can improve mineral nutrition (P, N, S, K, Zn, Cu…) and water uptake [4- 5]. We have investigated in pea plants grown in interaction with a rhizobium strain, to what extent the negative impact of water deficit could…

Une découverte sur un champignon au service des vignes

Article qui cite l'UMR Agroécologie en particulier l'équipe de D. van Tuinen (interviewé) du pôle IPM SPE (EA) IPM UMR; Une équipe internationale à laquelle a collaboré l’UMR Agroécologie de Dijon a percé les mystères du génome d'un champignon qui rend les plantes plus fortes. Une grande avancée scientifique qui pourrait profiter aux viticulteurs dans les prochaines années.

Blue-copper binding proteins of Medicago truncatula: Characterization of the expression of two genes related to the arbuscular mycorrhizal symbiosis

International audience; Expression profiling of two paralogous arbuscular mycorrhizal (AM)-specific blue copper-binding gene (MtBcpla and MtBcp1b) isoforms was performed by real-time quantitative polymerase chain reaction in wild-type Medicago truncatula Jemalong 5 (J5) during the mycorrhizal development with Glomus intraradices for up to 7 weeks. Timecourse analysis in J5 showed that expression of both MtBcp1 genes increased continuously and correlated strongly with the colonization intensity and arbuscule content. MtPT4, selected as a reference gene of the functional plant-fungus association, showed a weaker correlation to mycorrhizal development. In a second experiment, a range of mycorr…

Agronomic Management of Indigenous Mycorrhizas

Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in …

Proteomics: a functional genomic approach for studying mycorrhizal interactions in legumes

Mycorrhizal research in Dijon: from the gene to the field

International audience

Heavy metals in sewage sludges contribute to their adverse effects on the arbuscular mycorrhizal fungusGlomus mosseae

Applying sewage sludges to agricultural land is a widespread practice because of the sludges’ agronomic value as a source of plant nutrients and organic matter. Nevertheless, sludges often contain micropollutants that can constitute a menace for health and the environment. Arbuscular mycorrhizal fungi are sensitive to sewage sludges that have been spiked, or not, with metallic trace elements (MTE). Here we have investigated if MTE in sewage sludges could be responsible for effects on mycorrhizal development betweenGlomus mosseae andMedicago truncatula. The impact of a dehydrated or composted urban sewage sludge spiked or not with MTE, was tested on spore germination and root colonization by…

Glomalean spores and their DNA(s)

International audience

Clonage d'un gène de champignon arbusculaire fonctionnel lors de l'endomycorhization

National audience

Symbiose ou pathogenèse? Quels peuvent être les mécanismes moléculaires déterminants?

National audience

The membrane proteome of Medicago truncatula roots displays qualitative and quantitative changes in response to arbuscular mycorrhizal symbiosis

International audience; Arbuscular mycorrhizal (AM) symbiosis that associates roots of most land plants with soil-borne fungi (Glomeromycota), is characterized by reciprocal nutritional benefits. Fungal colonization of plant roots induces massive changes in cortical cells where the fungus differentiates an arbuscule, which drives proliferation of the plasma membrane. Despite the recognized importance of membrane proteins in sustaining AM symbiosis, the root microsomal proteome elicited upon mycorrhiza still remains to be explored. In this study, we first examined the qualitative composition of the root membrane proteome of Medicago truncatula after microsome enrichment and subsequent in dep…

Do crop genotypes have residual effects on Glomeromycota communities in agro-systems

International audience

BioVine project - Increase plant health through mycorrhizal fungi

National audience; Organic vineyards still rely on large external inputs to control harmful organisms. BIOVINE will develop natural solutions based on plant diversity to control pests and reduce pesticide dependence. The capacity of plants of increasing the ecosystem resistance to pests and invasive species is a well-known ecosystem service. However, monocultures like vineyards do not exploit the potential of plant diversity. BIOVINE aims to develop new viticultural systems based on increased plant diversity within (e.g. cover crops) and/or around vineyards by planting selected plant species for the control of arthropods, soil-borne pests (oomycetes, fungi, nematodes), and foliar pathogens.…

Signal-related gene responses in beneficial root interactions with non-rhizobial microorganisms

International audience

Diversity of arbuscular mycorrhizal fungi and their identification in roots and soil using nested PCR

International audience

A search for myosin in elongating hyphae of Neurospora crassa

International audience

Identification of arbuscular mycorrhizal fungi in soil and roots of plant colonizing zinc wastes in southern Poland

Identification of a 47Kd calmodulin-binding protein as an actin-binding protein in Neurospora crassa

International audience

Regional-scale analysis of arbuscular mycorrhizal fungi: the case of Burgundy vineyards

SPE IPM INRA UB; Aim : To improve knowledge of arbuscular fungal communities for a sustainable management in vineyards. Methods and results : In 16 plots across Burgundy under contrasted soil properties and agricultural practices, we assessed arbuscular mycorrhizal fungal (AMF) diversity in vine roots, using pyrosequencing of ribosomal Internal Transcribed Spacers (ITS). AMF sequences could be retrieved from all plots across Burgundy, both in organic and in conventional vineyards with high chemical inputs. Sequences from the survey were almost exclusively affiliated to molecular taxa in the Glomerales, including six “core species” found in all plots, corresponding to 77% of all sequences, s…

Mycorhizogene mushrooms to arbuscules and associated bacteria of precious allies for plant growth and health

National audience

Genes encoding transcription factors in Glomus intraradices and their expression at the appressoria stage of arbuscular mycorrhiza interactions

International audience; Molecular pathways governing the life cycle of arbuscular mycorrhizal (AM) fungi and their symbiotic interactions with root tissues are not yet fully understood. Most studies fo fungal responses to host plants have targeted developmental stages before root contact (germinating spores), or after root colonization (intraradical mycelium). We are focusing on the early cell events of appressoria contact with the root surface which are essential to the successful outcome of the AM symbiosis. Recent monitoring of Glomus intraradices gene expression at this stage has revealed differential fungal responses to roots of host and non-host (Myc- mutants) M. truncatula (Seddas et…

Heavy metals in sewage sludges contribute to their adverse effects on the arbuscular mycorrhizal fungus Glomus mosseae

International audience

Symbiosis-related plant genes modulate molecular responses in an arbuscular mycorrhizal fungus during early root interactions.

To gain further insight into the role of the plant genome in arbuscular mycorrhiza (AM) establishment, we investigated whether symbiosis-related plant genes affect fungal gene expression in germinating spores and at the appressoria stage of root interactions. Glomus intraradices genes were identified in expressed sequence tag libraries of mycorrhizal Medicago truncatula roots by in silico expression analyses. Transcripts of a subset of genes, with predicted functions in transcription, protein synthesis, primary or secondary metabolism, or of unknown function, were monitored in spores and germinating spores and during interactions with roots of wild-type or mycorrhiza-defective (Myc–) mutan…

An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen

International audience; * • Mechanisms of root penetration by arbuscular mycorrhizal (AM) fungi are unknown and investigations are hampered by the lack of transformation systems for these unculturable obligate biotrophs. Early steps of host infection by hemibiotrophic fungal phytopathogens, sharing common features with those of AM fungal colonization, depend on the transcription factor STE12. * • Using degenerated primers and rapid amplification of cDNA ends, we isolated the full-length cDNA of an STE12-like gene, GintSTE, from Glomus intraradices and profiled GintSTE expression by real-time and in situ RT-PCR. GintSTE activity and function were investigated by heterologous complementation …

Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis

International audience; The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but thi…

Expression profiling of up-regulated plant and fungal genes in early and late stages of Medicago truncatula - Glomus mosseae interactions

International audience

Impact of a new bio-pesticide produced by Paenibacillus sp. strain B2 on the genetic structure and density of soil bacterial communities

The effect of paenimyxin, a new biopesticide produced by Paenibacillus sp. strain B2, on the density of soil bacterial communities was assessed by colony counting and by 16S rDNA and nirK quantitative polymerase chain reaction (PCR). Paenimyxin had a negative effect on the bacterial colony-forming unit (CFU) number, which was significantly reduced 2 and 4 days after treatment. The effect of paenimyxin on cultivatable bacteria was negligible 7 days after treatment. Approximately 107 16S rDNA sequences per gram of soil (dry weight) were detected by quantitative PCR in all samples. Paenimyxin did not affect the quantification of 16S rDNA or of the denitrifying bacterial community. In addition,…

Signposting compatibility events initiating the mycorrhizal route

International audience

Spécificité écologique de la symbiose mycorhizienne à arbuscules formée par les plantes Agrostis capillaris et Lolium perenne

National audience

Molecular characterization and gene analysis of arbuscular mycorrhizal fungi

International audience

Champignons mycorhiziens et symbiose mycorhizienne, les as de la nutrition végétale

Prod 2018-228 SPE IPM INRA UB; National audience

Les mycorhizes, le sol et le développement végétal

International audience

Monitoring fluctuations of an arbuscular mycorrhizal fungal community in plants roots and soil

International audience

Une approche rapide pour le suivi de la colonisation mycorhizienne à arbuscules des plantes en agriculture

National audience

Plant beneficiating from arbuscular mycorrhizal symbiosis: impact of fungal diversity and soil fertilization

Gènes activés lors de l'interaction racine / Glomus mosseae chez Medicago truncatula

National audience

Recherche de gènes codant des facteurs de transcription fongiques impliqués dans l’établissement de la symbiose mycorhizienne à arbuscules

National audience

Changed protein pattern during heat shock and conidiogenous shift in Neurospora crassa

International audience

Arbuscular mycorrhizal fungi, partners of the rhizostabilization proccess of an orphan mining site

International audience

Arbuscular mycorrhizal plants: a fruitful interaction to promote sustainable agriculture and soil quality

International audience

Arbuscular mycorrhizal fungi, partners of the rhizostabilization process of an orphan mining site

International audience

Identification of functional markers of mycorrhiza efficiency in vineyard

Arbuscular mycorrhizal fungi form a mutualistic symbiotic association with more than 80% ofland plants, including vines. Advantages of this mutualistic symbiosis are countless. Rootcolonisation by mycorrhizal fungi is mainly evaluated through staining and microscopicobservation. However those technics do not allow to differentiate different mycorrhizal fungi.In order to overcome those limits other tools, like antibodies, isoenzymes and molecular biologytechnics, can be used. Nevertheless, all of these methods “only” allow detection of the presenceof mycorrhizal fungi, whereas no information is provided on the proper mycorrhizal symbiosisfunctioning, and therefore on the benefits provided to…

Services écosystémiques rendus par la symbiose mycorhizienne à arbuscule au vignoble

National audience; Qu’appelle-t-on symbiose mycorhizienne ?Le sol est un milieu vivant puisque dans quelques grammes de terre fine se trouvent environ 200 milliards de bactéries, 100 km de filaments de champignons et 200 000 insectes, vers et protozoaires (figure 1). Cette vie souterraine va partager son habitat (le sol) avec les ceps de vigne. Ce fameux « vivre ensemble » est alors défini par le terme « symbiose » (du grec syn : ensemble ; et bios : vivre). Cette définition ne fait pas de distinction vis-à-vis des modalités d’interaction qui peuvent s’établir entre les deux organismes impliqués. Ainsi, des interactions neutres, ou encore du véritable parasitisme, pour lequel un partenaire …

BioVine project - Increase plant health through mycorrhizal fungi

National audience; Organic vineyards still rely on large external inputs to control harmful organisms. BIOVINEwill develop natural solutions based on plant diversity to control pests and reduce pesticidedependence. The capacity of plants of increasing the ecosystem resistance to pests and invasivespecies is a well-known ecosystem service. However, monocultures like vineyards do notexploit the potential of plant diversity. BIOVINE aims to develop new viticultural systemsbased on increased plant diversity within (e.g. cover crops) and/or around vineyards by plantingselected plant species for the control of arthropods, soil-borne pests (oomycetes, fungi,nematodes), and foliar pathogens. Candid…

Tolérance au cadmium et mécanismes de détoxification chez le pois mycorhizé

National audience

Fungal genes related to calcium homeostasis and signalling are upregulated in symbiotic arbuscular mycorrhiza interactions

Fluctuations in intracellular calcium levels generate signalling events and regulate different cellular processes. Whilst the implication of Ca2+ in plant responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary messenger in the fungal symbiont. The spatio-temporal expression pattern of putatively Ca2+-related genes of Glomus intraradices BEG141 encoding five proteins involved in membrane transport and one nuclear protein kinase, was investigated during the AM symbiosis. Expression profiles related to successful colonization of host roots were observed in interactions of G. intraradices with roots of wild-ty…

Molecular detection and monitoring of fungal plant symbionts

International audience

Rôle du facteur de transcription fongique GintSTE dans l’établissement de la symbiose mycorhizienne à arbuscules

National audience

Étude de l’impact des pratiques culturales sur le fonctionnement de la symbiose mycorhizienne à arbuscule dans un système agroforestier

International audience; Au milieu du 20ème siècle, l’utilisation massive d’intrants chimiques a fortement réduit la biodiversité, la fertilité du sol, a augmentée l’érosion hydrique et la compaction du sol. La mise en place de nouveaux itinéraires de culture dans lesquels l’arbre a un rôle prépondérant pourrait devenir un élément clé d’une agriculture plus durable. Les systèmes agroforestiers participent à la conservation du potentiel agricole des terres via une couverture végétale annuelle et une diversification de la production. Dans la symbiose mycorhizienne à arbuscule, le champignon apporte des éléments nutritifs nécessaires au développement de la plante, et reçoit en retour des ressou…

Host preference in dark septate root endophytes of prairie grasses

International audience; Microbiological examination of prairie grass roots usually reveals the presence of diverse mycorrhizal and dark septate endophytic (DSE) fungi. Some of these fungi can enhance plant resistance to abiotic stress in extreme environments. The host specificity of two DSE fungi isolated from pure stands of crested wheatgrass and Russian wildrye in southwest Saskatchewan was assessed in microcosms. Pure cultures of endophytic fungal isolates were obtained after plating surface sterile root pieces on Potato dextrose agar. Plugs containing these fungi were used to individually inoculate germinated surface sterile seeds of crested wheatgrass and Russian wildrye, and control p…

Carbon partitioning in a walnut-maize agroforestry system through arbuscular mycorrhizal fungi

National audience; In tree-based intercropping systems, roots of trees and crops are interacting and could influence ecosystem services provided by soil microorganisms. Here, the analysis of diversity of arbuscular mycorrhiza fungi (AMF) associated with roots of walnut and maize reveals differences. Of interest, Funneliformis genus is mainly associated with maize roots, and one OTU related to an uncultured Glomus, might form a common mycorrhizal network linking roots of both plants. In addition, the analysis of 13C of mycelium living in the surrounding environment of roots, suggest that part of the carbon derived from walnut trees could be transferred to maize plants. Our results suggest th…

Impact of the growth of different maize genotypes on arbuscular mycorrhizal fungi

International audience

Diversity of arbuscular mycorrhizal fungi colonising roots of the grass species Agrostis capillaris and Lolium perenne in a field experiment

Analysis of arbuscular mycorrhizal (AM) fungal diversity through morphological characters of spores and intraradicular hyphae has suggested previously that preferential associations occur between plants and AM fungi. A field experiment was established to investigate whether AM fungal diversity is affected by different host plants in upland grasslands. Indigenous vegetation from plots in an unimproved pasture was replaced with monocultures of either Agrostis capillaris or Lolium perenne. Modification of the diversity of AM fungi in these plots was evaluated by analysis of partial sequences in the large subunit (LSU) ribosomal RNA (rDNA) genes. General primers for AM fungi were designed for t…

Au vignoble, l’âge des ceps (8, 33 et 107 ans) modifie-t-il les communautés de champignons mycorhiziens à arbuscules ?

Les champignons mycorhiziens à arbuscules (CMA) sont des organismes clés des agro-écosystèmes. Ils fournissent de nombreux services écosystémiques au sol (stabilité, rétention de l’eau, …) et aux plantes (amélioration de la nutrition hydrominérale, amélioration de la résistance à différents stress, ...). Les communautés de CMA sont principalement caractérisées dans le sol et encore peu directement au niveau racinaire. De plus, les études se focalisent généralement sur un seul prélèvement racinaire au cours du cycle de développement d’une plante, qu’elle soit annuelle ou pérenne. La dynamique des communautés de CMA est encore moins étudiée, que ce soit à court ou à long terme. De nombreux fa…

Getting to the symbiotic proteome of Medicago truncatula

The Medicago truncatula hypermycorrhizal B9 mutant displays an altered response to phosphate and is more susceptible to Aphanomyces euteiches.

SPE IPM; National audience; Inorganic phosphate (Pi) plays a key role in the development of arbuscular mycorrhizal (AM) symbiosis, which is favoured when Pi is limiting in the environment. We have characterized the Medicago truncatula hypermycorrhizal B9 mutant for its response to limiting (P/10) and replete (P2) Pi. On P2, mycorrhization was significantly higher in B9 plants than in wild-type (WT). The B9 mutant displayed hallmarks of Pi-limited plants, including higher levels of anthocyanins and lower concentrations of Pi in shoots than WT plants. Transcriptome analyses of roots of WT and B9 plants cultivated on P2 or on P/10 confirmed the Pi-limited profile of the mutant on P2 and highli…

Symbiotic underground biodiversity and plant productivity

National audience

Ribosomal sequences as a tool to study and monitor arbuscular mycorrhizal fungi

International audience

Biovine project : Exploit biodiversity in viticultural systems to reduce pest damage and pesticide use, and increase ecosystems services provision

International audience

The use of genomic repeated sequences to characterize arbuscular mycorrhizal fungi

International audience

Exploring the Genome of glomeromycotan fungi

Chapitre 1; International audience; All fungi forming a mutualistic symbiosis with plant roots called arbuscular mycorrhiza were formerly grouped together in one order, the Glomales, placed in the Zygomycota (Morton 1993). Based on molecular analyses suggestingthat arbuscular mycorrhizal fungi should be separated from other fungal taxa, they were transferred a decade ago to the Glomeromy-cota , a new phylum created specifically for them (Schu¨ ssler et al. 2001). Whilst members of this monophyletic group originated from the same common ancestor as the Ascomycota and Basidiomycota, they have no obvious affinity to other major extant phylogenetic groups in the kingdom Fungi (James et al. 2006) …

Transcription of two blue copper-binding protein isogenes is highly correlated with arbuscular mycorrhizal development in Medicago truncatula.

International audience; Expression profiling of two paralogous arbuscular mycorrhizal (AM)-specific blue copper-binding gene (MtBcp1a and MtBcp1b) isoforms was performed by real-time quantitative polymerase chain reaction in wild-type Medicago truncatula Jemalong 5 (J5) during the mycorrhizal development with Glomus intraradices for up to 7 weeks. Time-course analysis in J5 showed that expression of both MtBcp1 genes increased continuously and correlated strongly with the colonization intensity and arbuscule content. MtPT4, selected as a reference gene of the functional plant-fungus association, showed a weaker correlation to mycorrhizal development. In a second experiment, a range of mycor…

Transcriptional responses of Medicago truncatula upon sulfur deficiency stress and arbuscular mycorrhizal symbiosis

International audience; Sulfur plays an essential role in plants' growth and development and in their response to various abiotic and biotic stresses despite its leachability and its very low abundance in the only form that plant roots can uptake (sulfate). It is part of amino acids, glutathione (GSH), thiols of proteins and peptides, membrane sulfolipids, cell walls and secondary products, so reduced availability can drastically alter plant growth and development. The nutritional benefits of symbiotic interactions can help the plant in case of S deficiency. In particular the arbuscular mycorrhizal (AM) interaction improves N, P and S plant nutrition, but the mechanisms behind these exchang…

EST sequencing for fungal genes expressed in the arbuscular symbiosis

International audience

Gene responses to non rhizobial beneficial microbe interactions in legumes

National audience

Molecular methods to evaluate AMF functionality in soil and in roots

International audience

Molecular methods to evaluate AMF in soil and in roots

International audience

Pea genes modulate symbiosis-associated fungal and plant molecular responses during late stages of the arbuscular mycorrhizal symbiosis

International audience

Ressource exchanges in leguminous-gramineous associations: impact of multitrophic associations with beneficial microbes

International audience

Le rôle des mycorhizes et le lien avec les pratiques agricoles dans les noyeraies et autres cultures

- Présentation du projet Mycoagra 2017 – 2020 : sensibiliser le monde agricole à l’importance des réseaux mycorhiziens pour une production durable en noyeraie et maïsiculture [br/] - Présentation des associations mycorhiziennes et des principaux résultats sur les essais menés à Dijon depuis plus de 20 ans (Daniel WIPF)[br/] - L’agroforesterie en noyer – maïs : valorisation des réseaux mycorhiziens (Pierre Emmanuel Courty)[br/] - Intérêts des couverts végétaux en noyeraie (table ronde avec les conseillers noix de la région)[br/] - Débat avec les producteurs sur les questions qu’ils se posent et les axes de recherche qui les intéressent

Le microbiote de la vigne : de nouveaux paradigmes et une perspective pour la vigne de demain

Prod 2018-253a SPE EA BIOmE IPM INRA UB; National audience

Arbuscular mycorrhiza biotechnology and water quality preversation

National audience

Changes in the glomeromycota community in soils treated with a mix of pesticides

International audience

Persistence and effectiveness of Rhizophagus irregularis isolate IR27 on the fruit production of jujube trees in a semi-arid field condition

International audience

Sampling strategies and bias associated with the methods

International audience

Responses of above- and below-ground fungal symbionts to cessation of mowing in subalpine grassland

Abstract The cessation of mowing in subalpine grasslands promotes the dominance of Festuca paniculata leading to the reduction in plant diversity. Moreover, it affects positively the abundance of Epichloe sp. inhabiting F. paniculata leaves and negatively the soil density of arbuscular mycorrhizal fungi (AMF). We explored how the cessation of mowing influences root AMF communities in F. paniculata and the neighboring plants, and Epichloe sp alkaloids. Thirteen AMF operational taxonomical units were found. The neighboring plants affected positively the abundances of Aalpin and GLOM_7 whereas the interaction plant/management type influenced significantly Claroide_1 , GLOM_1 and GLOM_7 . The N…

Effect of soil management and weed controlm on the diversity and establishment of arbuscular mycorrhizal symbiosis colonisation in Mediterranean climate

International audience

Towards a cell-specific expression atlas of arbuscular mycorrhizal roots in the model legume Medicago truncatula

International audience

Genomics of arbuscular mycorrhizal fungi

International audience

Regulation of gene expression during endomycorrhizal infection

International audience

Stimulation of Defense Reactions in Medicago truncatula by Antagonistic Lipopeptides from Paenibacillus sp. Strain B2

ABSTRACT With the aim of obtaining new strategies to control plant diseases, we investigated the ability of antagonistic lipopolypeptides (paenimyxin) from Paenibacillus sp. strain B2 to elicit hydrogen peroxide (H 2 O 2 ) production and several defense-related genes in the model legume Medicago truncatula . For this purpose, M. truncatula cell suspensions were used and a pathosystem between M. truncatula and Fusarium acuminatum was established. In M. truncatula cell cultures, the induction of H 2 O 2 reached a maximum 20 min after elicitation with paenimyxin, whereas concentrations higher than 20 μM inhibited H 2 O 2 induction and this was correlated with a lethal effect. In plant roots in…

Developmental regulated fungal gene expression in mycorrhizal interactions with host and non host Medicago truncatula

International audience

Evaluation moléculaire in planta de la diversité des champignons mycorhizogènes dans des champs amendés avec des boues d'épuration

National audience

Mycorhization en viticulture : état des lieux et étude de l’intérêt au vignoble

SPEIPMUBINRA; Mycorhization en viticulture : état des lieux et étude de l’intérêt au vignoble. 13. Journée Technique du CIVB (Conseil Interprofessionnel du Vin de Bordeaux)

A multigene phylogenetic study of Tuber aestivum/uncinatum

International audience; Tuber aestivum and Tuber uncinatum share a complicated common history from a taxonomic point of view. Indeed, different previous studies have shown contradictory conclusions. For some authors, Tuber aestivum and Tuber uncinatum are one species and for others, they are two different species. In those studies, few phylogenetic markers have been used, mainly the ITS marker. However, it has become the standard in phylogenetic studies to combine several genes to obtain a more robust phylogenetic representation. In our study, we used 9 molecular markers and sampled fruiting bodies from different European populations including 14 Tuber “aestivum” types and 14 “uncinatum” ty…

Impact de l’inoculation au champ par Rhizophagus irregularis DAOM 197198 (AGTIV ®, Premier Tech, Canada) sur le rendement et la nutrition de 4 variétés de pommes de terre sur 3 parcelles aux propriétés édaphiques différentes

Différents services écosystémiques rendus par les champignons mycorhiziens à arbuscules (CMA) ont été mis en évidence dans des expériences menées sur différentes plantes, que ce soit en conditions contrôlées ou au champ. Les CMAs permettent par exemple, dans des conditions adéquates, d’améliorer la production de biomasse ainsi que le rendement, la qualité et les propriétés organoleptiques de nombreux produits d’intérêt pour l’industrie agro-alimentaire. Cependant, peu d’études se sont intéressées à l’impact de l’inoculation d’un CMA possédant une Autorisation de Mise sur le Marché au champ sur le rendement et la qualité des produits agricoles. Nous avons étudié l’impact de l’inoculation par…

Expression of genes encoding membrane intrinsic proteins (MIP) in arbuscular mycorrhizal parsley, tobacco and fababean

International audience