Search results for "MYCORHIZE"
showing 10 items of 57 documents
Priming: getting ready for battle
2006
International audience; Infection of plants by necrotizing pathogens or colonization of plant roots with certain beneficial microbes causes the induction of a unique physiological state called “priming.” The primed state can also be induced by treatment of plants with various natural and synthetic compounds. Primed plants display either faster, stronger, or both activation of the various cellular defense responses that are induced following attack by either pathogens or insects or in response to abiotic stress. Although the phenomenon has been known for decades, most progress in our understanding of priming has been made over the past few years. Here, we summarize the current knowledge of p…
Spatial monitoring of gene activity in extraradical and intraradical developmental stages of arbuscular mycorrhizal fungi by direct fluorescent in si…
2008
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…
An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen
2009
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 …
The mycorrhizal soil infectivity and arbuscular mycorrhizal fungal spore communities in soils of different aged fallows in Senegal
2001
This work was carried out to determine the influence of the duration of fallow and of physico-chemical components of soils on the distribution of endomycorrhizal fungal spores and the mycorrhizal soil infectivity. The mycorrhization of indigenous plants from the fallows was examined and it was concluded that, except for Cassia obtusifolia, fungal colonization was poorly developed. No correlation was established between spore populations and duration of fallow or between grazed and fenced areas. The relationships between abundance of mycorrhizal spores and the physico-chemical characteristics of the soils were markedly variable among species of mycorrhizal fungi. The results did not provide …
Regional-scale analysis of arbuscular mycorrhizal fungi: the case of Burgundy vineyards
2016
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…
L'acacia au Sénégal
1996
La biodiversité des Glomales associés à #Acacia albida$ est étudiée en fonction de l'âge de l'arbre, des saisons et des propriétés physicochimiques du sol. Les Glomales sont récoltées jusqu'à 1,5 et 4,5 m dans les régions soudano-guinéennes et jusqu'à 16 et 35 m dans les régions sahéliennes. La culture in vitro de la forme intraracinaire des Glomales en présence de racines isolées a montré une diversité morphologique des souches. En complément à cette taxonomie morphologique, des marqueurs moléculaires ont permis d'étudier la variabilité génétique des Glomales en comparant les variations de séquences d'ADN extrait de spores et de fragments mycorhiziens. (Résumé d'auteur)
Evaluation of viticultural practices on arbuscular mycorrhizal fungi associated with grapevine
2021
Arbuscular mycorrhiza, a mutualistic symbiosis established between plants and arbuscular mycorrhizal fungi (AMF), provides many ecosystem services such as improved soil structure, increased plant growth and nutrition, and improved tolerance to biotic and abiotic stresses. However, intensive agricultural practices and the use of phytosanitary products as for example herbicide and fungicides, have a strong impact on communities of soil microorganisms, including arbuscular mycorrhizal fungi, as well as on biological mechanisms within the ecosystem. This thesis wotk is part of the European Biovine project supported by the European Commission through the CORE Organic Cofund. The aim of this rese…
Biofonctionnements des sols tropicaux et mode de gestion des terres
2000
L'effet de la symbiose mycorhizienne sur la croissance du mil a été étudié en conditions contrôlées. Le sol collecté au sud du Sénégal dans un champ cultivé et dans une jachère de 17 ans a été mélangé et stérilisé. Il a ensuite été inoculé avec le #Glomus aggregatum$. La croissance de plants de mil cultivés sur ce sol a été comparée à une série témoin, cultivée sur sol non inoculé. La mycorhization des racines de mil a été faible. Elle n'a pas provoqué de réaction de stimulation de croissance. Cette absence de réponse pourrait s'expliquer par l'utilisation d'une souche exotique et non d'une souche indigène de champignon mycorhizien. (Résumé d'auteur)
Conférence invitée : " Mécanismes et gestion de la symbiose mycorhizienne dans les agro-écosystèmes"
2017
National audience; Présentations et échanges sur les résultats de l’INRA à propos desmycorhizes : quelles stratégies développées par les plantes pour mieuxutiliser les ressources naturelles du sol ? Comment favoriser desconditions favorables à l'installation et à la vie des champignonsbénéfiques du sol ? Quelle influence la nature du sol a-t’elle sur laquantité et la diversité de champignons mycorhiziens ? Quid desintrants ? Les fongicides ont-ils vraiment un effet délétère sur leschampignons Mycorhiziens ? La résistance des plantes aux pesticidespeut-elle être favorisée par les mycorhizes ?
Strategies for analyzing interactions between arbuscular mycorrhiza and bacteria
2013
National audience