Papers by Pierre-Emmanuel COURTY
Il y a 450 millions d’années, des algues vertes conquirent les terres émergées : elles allaient d... more Il y a 450 millions d’années, des algues vertes conquirent les terres émergées : elles allaient devenir les plantes que nous connaissons. Cette conquête des continents, n’a probablement été rendue possible que par le développement d’une association bénéfique entre les racines des plantes et des champignons. Cette association ancestrale, appelée la mycorhize à arbuscules, est la plus ancienne symbiose mutualiste entre plantes et microorganismes.Cette monographie synthétise les connaissances sur la mycorhize à arbuscules et les services rendus dans les agroécosystèmes, leurs impacts sur les interactions plus larges entre organismes (interactions plante-plante et interactions multi-trophiques plantes-champignons mycorhiziens-bactéries), les liens entre itinéraires de culture et mycorhization. Enfin, elle comporte un focus sur le projet « Mycoagra » qui aborde ces aspects sur le noyer
Methods in Rhizosphere Biology Research, 2019
We developed a new protocol to study arbuscular mycorrhizal fungal (AMF) communities in Bordeaux ... more We developed a new protocol to study arbuscular mycorrhizal fungal (AMF) communities in Bordeaux vineyards in a standardized way, in order to compare results obtained over years and between locations. To this end, we first used grapevine root samples instead of soil samples to avoid AMF spores or hyphae interacting with cover plants. We next increased the number of grapevine samples to obtain more representative coverage of AMF communities while decreasing variability intra-vineyard, especially for the larger parcels. In addition, we adapted the DNA extraction protocol dedicated to soil samples to grapevine roots, as a way to increase the yield and the purity of samples. These features, coupled to the choice of the LSU-D2 region as the molecular marker for high-throughput sequencing (MiSeq® technology), further allowed us to assess the AMF populations of Bordeaux vineyards.
Le Centre pour la Communication Scientifique Directe - HAL - Université de Nantes, 2021
National audienceQu’appelle-t-on symbiose mycorhizienne ?Le sol est un milieu vivant puisque dans... more National audienceQu’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 se nourrit aux dépens de l’autre, peuvent exister ou coexister. Le cas le plus intéressant est celui pour lequel l’association entre les deux partenaires est durable et conduit à des bénéfices réciproques (mutualisme) ; c’est la symbiose telle qu’elle a été définie par Frank et de Bary, et c’est le cas de la mycorhize.Une mycorhize (du grec – mukès : champignon, et rhiza : racine) est une association symbiotique à bénéfices réciproques qui s’établit naturellement entre les racines des plantes et certains champignons du sol. Il existe différents types de mycorhizes, qui dépendent principalement du type de végétal concerné et du profil de colonisation fongique dans les tissus végétaux. La vigne, comme 80 % des plantes terrestres (dont la majorité des plantes cultivées), forme des endomycorhizes à arbuscules. « Endomycorhize », car les champignons endomycorhiziens vont pénétrer les cellules corticales de la racine et « à arbuscules » car la structure d’échanges entre les deux partenaires, mise en place par le champignon à l’intérieur des cellules de la plante, ressemble à un petit arbuste. La mycorhize à arbuscules est une symbiose ancestrale (-400 millions d’années), et les champignons du sol (champignons endomycorhiziens à arbuscules : CMAs) impliqués font partie des Gloméromycètes
Journal of Advanced Research, 2021
Methods in Rhizosphere Biology Research, 2019
It is well established that arbuscular mycorrhiza (AM) symbiotic fungi contribute to the scavengi... more It is well established that arbuscular mycorrhiza (AM) symbiotic fungi contribute to the scavenging of soil mineral nutrients in exchange for photosynthetically fixed organic carbon in the large majority of land plants. However, plants are naturally interconnected by a common mycorrhizal network (CMN), and the terms of trade as well as developmental interactions between plants connected with a shared fungal partner are still poorly understood. To facilitate the decrypting of such complex relationships, model systems allowing the study of two or more interconnected plants have been developed. Compartmented microcosms were designed to physically separate the roots of studied plants (using meshes) that can in fact only interact through a CMN the integrity of which can be controlled. Here, we report on recently published results relative to the implementation of various specifically designed microcosms to better understand the role in plant-plant relationships of the CMN and that of the...
New Phytologist, 2013
Arbuscular mycorrhizal (AM) fungi contribute to plant nitrogen (N) acquisition. Recent studies de... more Arbuscular mycorrhizal (AM) fungi contribute to plant nitrogen (N) acquisition. Recent studies demonstrated the transport of N in the form of ammonium during AM symbiosis. Here, we hypothesize that induction of specific ammonium transporter (AMT) genes in Sorghum bicolor during AM colonization might play a key role in the functionality of the symbiosis. For the first time, combining a split-root experiment and microdissection technology, we were able to assess the precise expression pattern of two AM-inducible AMTs, SbAMT3;1 and SbAMT4. Immunolocalization was used to localize the protein of SbAMT3;1. The expression of SbAMT3;1 and SbAMT4 was greatly induced locally in root cells containing arbuscules and in adjacent cells. However, a split-root experiment revealed that this induction was not systemic. By contrast, a strictly AM-induced phosphate transporter (SbPt11) was expressed systemically in the split-root experiment. However, a gradient of expression was apparent. Immunolocalization analyses demonstrated that SbAMT3;1 was present only in cells containing developing arbuscules. Our results show that the SbAMT3;1 and SbAMT4 genes are expressed in root cortical cells, which makes them ready to accommodate arbuscules, a process of considerable importance in view of the short life span of arbuscules. Additionally, SbAMT3;1 might play an important role in N transfer during AM symbiosis.
Figure of phylogenetic tree of GRAS proteins in the SHORT ROOT subfamily. AM-induced genes from P... more Figure of phylogenetic tree of GRAS proteins in the SHORT ROOT subfamily. AM-induced genes from P. axillaris (Peaxi), M. truncatula (Medtr) and L. japonicus (Lojap) are marked with red circles. The functionally characterized NSP1 gene from M. truncatula is marked with a blue circle. The closest homologues in A. thaliana (AT) are highlighted with red frames. Potri: P. trichocarpa; Sobic: S bicolor; Bradi: B. distachyon; Os: O. sativa). The distance bar indicates substitutions per site. (PDF 63 kb)
Figure of phylogenetic tree of GRAS proteins in the SCARECROW subfamily. AM-induced genes from P.... more Figure of phylogenetic tree of GRAS proteins in the SCARECROW subfamily. AM-induced genes from P. axillaris, (Peaxi), M. truncatula (Medtr), and L. japonicus (Lojap) are marked with red circles. The closest homologue in A. thaliana (AT) is highlighted with a red frame. Potri: P. trichocarpa; Sobic: S bicolor; Bradi: B. distachyon; Os: O. sativa). The distance bar indicates substitutions per site. (PDF 59 kb)
Figure of phylogenetic tree of GRAS proteins in the AM-specific Pt20/MIG subfamily. AM-induced ge... more Figure of phylogenetic tree of GRAS proteins in the AM-specific Pt20/MIG subfamily. AM-induced genes from P. axillaris (Peaxi), M. truncatula (Medtr), and L. japonicus (Lojap) are marked with red circles; the functionally tested MIG1 gene from M. truncatula is marked with a blue circle. The closest homologue in A. thaliana (AT) is highlighted with a red frame. Potri: Populus trichocarpa. The distance bar indicates substitutions per site. (PDF 62 kb)
Table showing the global comparison of GO terms induced or repressed in wild type and ram1. Genes... more Table showing the global comparison of GO terms induced or repressed in wild type and ram1. Genes were assigned to biochemical and cellular functions based on common GO terms. Only GO terms with significant overrepresentation (p
Table listing the genes induced at least 5-fold in the wild type and their expession in ram1. All... more Table listing the genes induced at least 5-fold in the wild type and their expession in ram1. All AM-incucible genes were sorted according to their predicted functional category as in Fig. 2. Expression values (RPKM) are given for mycorrhizal wild type (wt-M_RPKM means), wild type control roots (wt-NM_RPKM means), mycorrhizal ram1 (ram1-M_RPKM means), and ram1 control roots (ram1-M_RPKM means). The respective induction ratio (AM vs. control roots) are given for the wildtype (column P) and ram1 (Column BB). (XLSX 542 kb)
Table listing the complete gene data set of this study. (XLSX 4836 kb)
Figure of phylogenetic tree of GRAS proteins in the AM-specific Os19 subfamily. AM-induced genes ... more Figure of phylogenetic tree of GRAS proteins in the AM-specific Os19 subfamily. AM-induced genes in L. japonicus (Lojap) and P. axillaris (Peaxi) are marked with red circles. The closest homologue in A. thaliana (AT) is highlighted with a red frame. Potri: P. trichocarpa; Sobic: S. bicolor; Bradi: B. distachyon; Os: O. sativa). The distance bar indicates substitutions per site. (PDF 58 kb)
Figure of phylogenetic tree of GRAS proteins in the SCARECROW-LIKE3 subfamily. AM-induced genes f... more Figure of phylogenetic tree of GRAS proteins in the SCARECROW-LIKE3 subfamily. AM-induced genes from P. axillaris (Peaxi), M. truncatula (Medtr), and L. japonicus (Lojap) are marked with red circles. The closest homologue in A. thaliana (AT) is highlighted with a red frame. Potri: P. trichocarpa; Sobic: S bicolor; Bradi: B. distachyon; Os: O. sativa). The distance bar indicates substitutions per site. (PDF 62 kb)
Summary table of RNAseq experiment. (PDF 55 kb)
Expression of AM-related genes involved at different stages of AM interaction. Expression analysi... more Expression of AM-related genes involved at different stages of AM interaction. Expression analysis by qPCR of D27, CCD8, SYMRK, VAPYRIN, PT4, and RAM2 in wild type (dark grey columns) and ram1 mutants (light grey columns) with the AM fungus R. irregularis (Ri) or in nonmycorrhizal controls. Note logarithmic scale of y-axis. Identities and gene names of GRAS genes can be found in Additional file 3. (PDF 40 kb)
SSSA Book Series, 2015
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Soil Biology and Biochemistry, 2013
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Papers by Pierre-Emmanuel COURTY