Fungal lipochitooligosaccharide symbiotic signals in arbuscular mycorrhiza.
Résumé
Arbuscular mycorrhiza (AM) is a root endosymbiosis between plants and glomeromycete fungi. It is the most widespread terrestrial plant symbiosis, improving plant uptake of water and mineral nutrients. Yet, despite its crucial role in land ecosystems, molecular mechanisms leading to its formation are just beginning to be unravelled. Recent evidence suggests that AM fungi produce diffusible symbiotic signals. Here we show that Glomus intraradices secretes symbiotic signals that are a mixture of sulphated and non-sulphated simple lipochitooligosaccharides (LCOs), which stimulate formation of AM in plant species of diverse families (Fabaceae, Asteraceae and Umbelliferae). In the legume Medicago truncatula these signals stimulate root growth and branching by the symbiotic DMI signalling pathway. These findings provide a better understanding of the evolution of signalling mechanisms involved in plant root endosymbioses and will greatly facilitate their molecular dissection. They also open the way to using these natural and very active molecules in agriculture.
Mots clés
CARBOHYDRATE SEQUENCE
CHOMATOGRAPHY HIGH PRESSURE LIQUID
CAROTA CHEMISTRY METABOLISM MICROBIOLOGY
LIPOPOLYSACCHARIDES CHEMISTRY METABOLISM
MEDICAGO TRUNCATULA CHEMISTRY GROWTH & DEVELOPMENT METABOLISM MICROBIOLOBY
MOLECULAR SEQUENCE DATA
MYCORRHIZAE METABOLISM
EXTRACTS CHEMISTRY METABOLISM
PLANT ROOTS CHEMISTRY GROWTH & DEVELOPMENT METABOLISM MICROBIOLOGY
SIGNAL TRANSDUCTION
SPORES FUNGAL CHEMISTRY METABOLISM SYMBIOSIS
AM
SUSTAINABLE DEVELOPMENT