{"id":6246,"date":"2016-04-19T15:23:14","date_gmt":"2016-04-19T15:23:14","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=6246"},"modified":"2016-04-26T08:57:12","modified_gmt":"2016-04-26T08:57:12","slug":"phd-defense-c-pellegrin","status":"publish","type":"post","link":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=6246","title":{"rendered":"PhD Defense: C. Pellegrin"},"content":{"rendered":"
\n

The defense will be held the 26th April at 9h00<\/strong>\u00a0in the\u00a0conference room of the INRA campus at Champenoux<\/span>.<\/p>\n

\"these<\/p>\n

Titre<\/span> :\u00a0<\/span>Analyse d\u2019effecteurs du champignon ectomycorhizien Laccaria bicolor<\/i> : approches bio-informatiques et fonctionnelles<\/b><\/span><\/p>\n

R\u00e9sum\u00e9 :<\/h1>\n

La symbiose ectomycorhizienne associe les racines d\u2019un arbre aux hyphes d\u2019un champignon, conduisant \u00e0 un \u00e9change r\u00e9ciproque de nutriments entre les deux partenaires. La colonisation fongique massive du cortex racinaire est caract\u00e9ris\u00e9e par la formation d\u2019une interface symbiotique, le r\u00e9seau de Hartig. Le fonctionnement de cette interface symbiotique n\u2019est pas parfaitement \u00e9lucid\u00e9 mais l\u2019acquisition du g\u00e9nome du symbionte ectomycorhizien Laccaria bicolor a permis d\u2019identifier des petites prot\u00e9ines pr\u00e9dites s\u00e9cr\u00e9t\u00e9es, les MiSSPs (Mycorrhiza-induced Small Secreted Proteins). Mon projet de th\u00e8se avait pour objectifs la comparaison des s\u00e9cr\u00e9tomes, notamment les petites prot\u00e9ines s\u00e9cr\u00e9t\u00e9es (SSPs), de champignons ectomycorhiziens et saprotrophes, la localisation subcellulaire in planta et l\u2019analyse fonctionnelle de MiSSPs de L. bicolor. L\u2019analyse bioinformatique a notamment permis de r\u00e9v\u00e9ler des clusters de SSPs fortement conserv\u00e9es entre champignons ectomycorhiziens et saprotrophes ou sp\u00e9cifiques de champignons ectomycorhiziens, mettant en lumi\u00e8re que les champignons ectomycorhiziens partagent des SSPs avec leurs anc\u00eatres saprotrophes mais poss\u00e8dent aussi d\u2019autres SSPs sp\u00e9cifiques \u00e0 leur mode de vie.<\/p>\n

Un jeu de MiSSPs de L. bicolor appartenant \u00e0 un \u00ab core-regulon \u00bb ont \u00e9t\u00e9 localis\u00e9es in planta, montrant que trois d\u2019entre eux sont capables de cibler sp\u00e9cifiquement des compartiments subcellulaires de la cellule v\u00e9g\u00e9tale. La recherche d\u2019interactant pour l\u2019effecteur candidat MiSSP8 n\u2019a pas permis l\u2019identification d\u2019un interactant, mais le motif r\u00e9p\u00e9t\u00e9 DWRR pr\u00e9sent dans la s\u00e9quence de MiSSP8 est unique aux champignons et est partag\u00e9 par une famille de prot\u00e9ine fongique de champignons majoritairement saprotrophes. Ces r\u00e9sultats sugg\u00e8rent que l\u2019utilisation de SSPs comme moyen de communication est g\u00e9n\u00e9rique chez les champignons et d\u00e9montrent aussi qu\u2019au moins une petite prot\u00e9ine s\u00e9cr\u00e9t\u00e9e requise pour la symbiose de L. bicolor a \u00e9volu\u00e9e \u00e0 partir de prot\u00e9ines de champignons saprotrophes.<\/p>\n

Abstract :<\/h1>\n

Roots of most trees form ectomycorrhizal (ECM) symbiosis with mutualistic soil-borne fungi, relying on a bi-directional exchange of nutrients between the two partners. Fungal colonization of cortical root cells form the Hartig net, a symbiotic interface. Functioning of this symbiotic interface is not well known. However, Laccaria bicolor genome sequencing sheds the light on upregulated small-secreted proteins, so-called MiSSPs (Mycorrhiza-Small Secreted Proteins). Several L. bicolor MiSSPs were demonstrated as symbiosis effectors. My PhD project aims to compare secretomes, in particular SSPs, of fungal with different lifestyles and pursue functional analysis of MiSSPs of L. bicolor.<\/p>\n

Based on the clustering analysis, we identified clusters of SSPs shared between saprotrophic and ECM fungi and clusters of SSPs specific to ECM-fungi. This study highlights that ECM fungi share SSPs with their saprotrophic ancestors but also possess lifestyle specific SSPs.<\/p>\n

In planta subcellular localization of a set of MiSSPs belonging to a core-regulon showed that three of them are able to target different plant subcellular compartments. Functional analysis of the symbiosis effector MiSSP8 does not lead to the identification of a putative interactor but the repetitive motif DWRR of MiSSP8 protein sequence is unique to fungi and is shared with SSPs from saprotrophic ancestors. Our results suggest the use of SSPs as mean of communication is common and generic and show at least one SSPs required for ectomycorhizal symbiosis of L. bicolor has evolved from SSPs found in saprotrophic fungi.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

The defense will be held the 26th April at 9h00\u00a0in the\u00a0conference room of the INRA campus at Champenoux. Titre :\u00a0Analyse d\u2019effecteurs du champignon ectomycorhizien Laccaria bicolor : approches bio-informatiques et fonctionnelles R\u00e9sum\u00e9 : La symbiose ectomycorhizienne associe les racines d\u2019un … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-6246","post","type-post","status-publish","format-standard","hentry","category-seminarmeeting"],"_links":{"self":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/6246","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6246"}],"version-history":[{"count":0,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/6246\/revisions"}],"wp:attachment":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6246"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6246"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6246"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}