Signaling events during initiation of arbuscular mycorrhizal symbiosis  

作　　者：Alexa M.Schmitz Maria J.Harrison 

机构地区：[1]Boyce Thompson Institute for Plant Research [2]Plant Pathology and Plant-Microbe Biology, Cornell University

出　　处：《Journal of Integrative Plant Biology》2014年第3期250-261,共12页植物学报（英文版）

基　　金：Financial support for this research program was provided by the US National Science Foundation (IOS‐0842720);an award from the US National Science Foundation Graduate Research Fellowship (DGE‐1144153)

摘　　要：Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal （AM） fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression.Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal （AM） fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression.

关 键 词：Arbuscular mycorrhizal fungi CHITIN CHITOOLIGOSACCHARIDE CUTIN LysM MAMP-triggered immunity Myc-LCO Nod factor STRIGOLACTONES SYMBIOSIS 

分 类 号：Q943[生物学—植物学]