固氮根瘤菌利用「脂質幾丁寡糖」(lipochitooligosaccharide)信號分子啟動與植物根的共生關係。曾有人提出,菌根真菌也為這一過程分泌化學信號,但這些分子的身份過去卻不清楚。現在,研究表明,與根瘤菌相似的是,菌根真菌的確產生「脂質幾丁寡糖」。這些共生信號在多個科的植物物種中刺激「叢枝菌根」的形成,同時刺激根部發育。這些數據提供了關於植物根部「內共生」中信號作用機制的演化的一個更為詳盡的畫面,並且可能為在農業中利用這些活性分子鋪平道路。(生物谷Bioon.com)
生物谷推薦原文出處:
Nature doi:10.1038/nature09622
Fungal lipochitooligosaccharide symbiotic signals in arbuscular mycorrhiza
Fabienne Maillet,Véréna Poinsot,Olivier André,Virginie Puech-Pagès,Alexandra Haouy,Monique Gueunier,Laurence Cromer,Delphine Giraudet,Damien Formey,Andreas Niebel,Eduardo Andres Martinez,Hugues Driguez,Guillaume Bécard& Jean Dénarié
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.