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

International audience

Signposting compatibility events driving the mycorrhizal route

International audience

Localisation de l’expression de gènes fongiques lors des différentes étapes de la mycorhization : développement de la méthode de RT-PCR in situ

National audience

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

National audience

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

International audience

Dissection of Genetic Cell Programmes Driving Early Arbuscular Mycorrhiza Interactions

The persistence through evolution of the arbuscular mycorrhiza (AM) symbiosis between Glomeromycota and plants is probably due to a widespread molecular dialogue between the two partners. Most studies have focussed on established mycorrhizal systems whilst evidence for cellular commitment of the symbiotic partners during early developmental phases is recent. Whereas spore germination by AM fungi can occur spontaneously, subsequent hyphal branching, appressoria differentiation, root penetration and intraradical development leading to symbiosis establishment are under the control of molecular interactions between the two partners. In this chapter, recent work on AM fungus–plant interactions i…

Signaling in AM symbiosis establishment: influence of plant symbiotic genes

International audience

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

International audience

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

International audience

Localisation et visualisation de transcrits fongiques in situ: Une méthode originale qui combine biologie moléculaire et microscopie confocale

National audience; Les Gloméromycètes, formant la symbiose mycorhizienne à arbuscules, sont des champignons biotrophes obligatoires qui sont intimement associés aux tissus végétaux qu’ils colonisent. Les techniques utilisées pour suivre l’expression des gènes fongiques dans les racines mycorhizées ne permettent pas de définir le profil spatio-temporel de leur activité. Afin de tracer l’activité transcriptionnelle fongique dans les racines mycorhizées, une méthode innovante, basée sur la RT-PCR in situ, a donc été développée. Cette technique permet de localiser, en microscopie optique confocale à balayage laser, des transcrits fongiques, à l’aide d’amorces spécifiques marquées par un fluoroc…

Localization of fungal gene expression at different stages of arbuscular mycorrhizal symbiosis : development of an in situ RT-PCR method

International audience

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

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…

Symbiosis-related plant genes modulate molecular responses in an arbuscular mycorrhizal fungus during early root interactions: molecular in vitro and in situ approaches

National audience

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 …

Signposting compatibility events initiating the mycorrhizal route

International audience

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

National audience

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

National audience

Changes in membrane lipid composition in ethanol- and acid-adapted Oenococcus oeni cells: characterization of the cfa gene by heterologous complementation

International audience; Cyclopropane fatty acid (CFA) synthesis was investigated in Oenococcus oeni. The data obtained demonstrated that acid-grown cells or cells harvested in the stationary growth phase showed changes in fatty acid composition similar to those of ethanol-grown cells. An increase of the CFA content and a decrease of the oleic acid content were observed. The biosynthesis of CFAs from unsaturated fatty acid phospholipids is catalysed by CFA synthases. Quantitative real-time-PCR experiments were performed on the cfa gene of O. oeni, which encodes a putative CFA synthase. The level of cfa transcripts increased when cells were harvested in stationary phase and when cells were gr…

Spatial monitoring of gene activity in extraradical and intraradical developmental stages of arbuscular mycorrhizal fungi by direct fluorescent in situ RT-PCR

International audience; Gene expression profiling based on tissue extracts gives only limited information about genes associated with complex developmental processes such as those implicated in fungal interactions with plant roots during arbuscular mycorrhiza development and function. To overcome this drawback, a direct fluorescent in situ RT-PCR methodology was developed for spatial mapping of gene expression in different presymbiotic and symbiotic structures of an arbuscular mycorrhizal fungus. Transcript detection was optimized by targeting the LSU rRNA gene of Glomus intraradices and monitoring expression of a stearoyl-CoA-desaturase gene that is consistently expressed at high levels in…

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

International audience

Corrigendum to “Spatial monitoring of gene activity in extraradical and intraradical developmental stages of arbuscular mycorrhizal fungi by direct fluorescent in situ RT-PCR” [Fungal Genet. Biol. 45 (2008) 1155–1165]