{"id":9377,"date":"2018-12-04T10:52:43","date_gmt":"2018-12-04T10:52:43","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=9377"},"modified":"2018-12-04T10:53:44","modified_gmt":"2018-12-04T10:53:44","slug":"phd-defense-a-maupetit","status":"publish","type":"post","link":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=9377","title":{"rendered":"PhD Defense: A. Maupetit"},"content":{"rendered":"

Agathe Maupetit soutiendra sa th\u00e8se, intitul\u00e9e “Potentiel \u00e9volutif et d\u00e9terminisme g\u00e9n\u00e9tique de caract\u00e8res d\u2019agressivit\u00e9 et morphologiques de l\u2019agent de la rouille du peuplier,Melampsora larici-populina<\/em>“, le mardi 18 d\u00e9cembre \u00e0 9h dans la salle de conf\u00e9rences \u00e0 l’Inra, devant le jury suivant :<\/p>\n

Marie Foulongne-Oriol, Charg\u00e9e de recherche, INRA Bordeaux, Rapporteure
\nBruno Le Cam, Directeur de recherche, INRA Angers, Rapporteur
\nChlo\u00e9 Delmas, Charg\u00e9e de recherche, INRA Bordeaux, Examinatrice
\nKatherine Hayden, Chercheuse, RGBE Edimbourg, Examinatrice
\nC\u00e9cile Robin, Directrice de recherche, INRA Bordeaux, Examinatrice
\nPascal Frey, Directeur de recherche, INRA Nancy, Directeur de th\u00e8se
\nFabien Halkett, Charg\u00e9 de recherche, INRA Nancy, Co-directeur de th\u00e8se, invit\u00e9
\nSt\u00e9phane De Mita, Charg\u00e9 de recherche, INRA Nancy, Co-directeur de th\u00e8se, invit\u00e9<\/p>\n

Agathe Maupetit will defend her\u00a0PhD thesis<\/i>, entitled “Evolutionary potential and genetic underpinnings of aggressiveness and morphological traits in the poplar rust fungus,<\/em>Melampsora larici-populina“, on Tuesday, December 18 at 9:00 am in the conference room at INRA<\/em>.<\/i><\/p>\n

R\u00e9sum\u00e9\u00a0:<\/strong>Pour lutter contre les agents phytopathog\u00e8nes, la s\u00e9lection de plantes r\u00e9sistantes est la strat\u00e9gie la plus rentable et la plus \u00e9cologique. Les r\u00e9sistances quantitatives, bas\u00e9es sur des m\u00e9canismes de r\u00e9sistances complexes, sont connues pour \u00eatre sujettes \u00e0 l\u2019\u00e9rosion, en cas d\u2019\u00e9volution de l\u2019agressivit\u00e9 des agents pathog\u00e8nes. L\u2019objectif de ce travail bas\u00e9 sur le pathosyst\u00e8me peuplier \u2013 rouille du peuplier(Melampsora larici-populina<\/em>) est d\u2019\u00e9valuer le potentiel \u00e9volutif des caract\u00e8res d\u2019agressivit\u00e9 et morphologiques du parasite par des approches de g\u00e9n\u00e9tique quantitative et d’identifier les bases g\u00e9n\u00e9tiques par g\u00e9n\u00e9tique d’association. Pour estimer la plasticit\u00e9, l\u2019h\u00e9ritabilit\u00e9 et les compromis \u00e9volutifs d\u2019un ensemble de caract\u00e8res quantitatifs, nous avons pr\u00e9cis\u00e9ment mesur\u00e9 leurs variations dans quatre populations contrast\u00e9es du champignon. Nous avons montr\u00e9 que le volume des spores est un caract\u00e8re h\u00e9ritable qui \u00e9volue rapidement. La quantit\u00e9 de myc\u00e9lium in planta<\/em>est aussi h\u00e9ritable mais tr\u00e8s conserv\u00e9e car sous s\u00e9lection stabilisante dans les populations \u00e9tudi\u00e9es. Le temps de latence, la taille des l\u00e9sions et le taux de sporulation pr\u00e9sentent une h\u00e9ritabilit\u00e9 faible, ce qui explique l\u2019absence d\u2019\u00e9volution observ\u00e9es au cours du temps pour ces trois caract\u00e8res. Les caract\u00e8res li\u00e9s \u00e0 la fonction de sporulation semblent \u00eatre les plus plastiques le long d\u2019un gradient de maturit\u00e9 foliaire. L\u2019ensemble de ces r\u00e9sultats sugg\u00e8re que la sporulation est la fonction la plus contrainte par l\u2019environnement biotique et donc la meilleure cible pour la mise en place de r\u00e9sistances durables chez le peuplier. Si aucune base g\u00e9n\u00e9tique de ces caract\u00e8res quantitatifs n\u2019a \u00e9t\u00e9 mise en \u00e9vidence, nous avons localis\u00e9 un locus d\u2019avirulence potentiel (Avr7) sur lequel une caract\u00e9risation fonctionnelle est envisag\u00e9e.<\/p>\n

Mots cl\u00e9s\u00a0:<\/strong>Champignon phytopathog\u00e8ne, g\u00e9n\u00e9tique quantitative, \u00e9volution, pouvoir pathog\u00e8ne, GWAS (\u00e9tude d\u2019association sur g\u00e9nome complet)<\/p>\n

Abstract:<\/strong>To control plant pathogens, breeding resistant plants is the most cost-effective and ecological strategy. Quantitative resistances, which are based on complex plant mechanisms, are known to be exposed to erosion through an increase of pathogens aggressiveness. Through the study the poplar \u2013 poplar rust (Melampsora larici-populina<\/em>) pathosystem, this work aims to estimate the evolutionary potential of aggressiveness and morphological traits using quantitative genetic approaches and to identify molecular bases through genome-wide association study. To estimate plasticity, heritability, and trade-offs for a set of quantitative traits, we precisely measured their variation in four contrasted pathogen populations. It appeared that spore volume is highly heritable and evolved rapidly. In planta<\/em>mycelium quantity is also heritable but constant because of stabilizing selection occurring in the studied populations. Latent period, lesion size and sporulation rate exhibit low heritability, which explains the absence of evolution during the studied time period. Traits involved in the sporulating function seem to be the most plastic ones along a leaf maturity gradient. Altogether, these results suggest that sporulating function is the more constraint by the biotic environment and thus the best target for the construction of durable resistance in poplar. No genetic underpinning has been found for quantitative traits, but we have identified a potential avirulence locus (Avr7), opening the way for its functional characterization.<\/p>\n

Key words:<\/strong>fungal plant pathogen, quantitative genetics, evolution, pathogenicity, GWAS (genome-wide association study)<\/p>\n","protected":false},"excerpt":{"rendered":"

Agathe Maupetit soutiendra sa th\u00e8se, intitul\u00e9e “Potentiel \u00e9volutif et d\u00e9terminisme g\u00e9n\u00e9tique de caract\u00e8res d\u2019agressivit\u00e9 et morphologiques de l\u2019agent de la rouille du peuplier,Melampsora larici-populina“, le mardi 18 d\u00e9cembre \u00e0 9h dans la salle de conf\u00e9rences \u00e0 l’Inra, devant le jury … 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":[4,8],"tags":[],"class_list":["post-9377","post","type-post","status-publish","format-standard","hentry","category-seminarmeeting","category-thesis"],"_links":{"self":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/9377","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=9377"}],"version-history":[{"count":0,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/9377\/revisions"}],"wp:attachment":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9377"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9377"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9377"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}