Molecular Regulation of Arbuscular Mycorrhizal Symbiosis

Plant-microorganism interactions at the rhizosphere level have a major impact on plant growth and plant tolerance and/or resistance to biotic and abiotic stresses. Of particular importance for forestry and agricultural systems is the cooperative and mutualistic interaction between plant roots and arbuscular mycorrhizal (AM) fungi from the phylum Glomeromycotina, since about 80% of terrestrial plant species can form AM symbiosis. The interaction is tightly regulated by both partners at the cellular, molecular and genetic levels, and it is highly dependent on environmental and biological variables. Recent studies have shown how fungal signals and their corresponding host plant receptor-mediated signalling regulate AM symbiosis. Host-generated symbiotic responses have been characterized and the molecular mechanisms enabling the regulation of fungal colonization and symbiosis functionality have been investigated. This review summarizes these and other recent relevant findings focusing on the molecular players and the signalling that regulate AM symbiosis. Future progress and knowledge about the underlying mechanisms for AM symbiosis regulation will be useful to facilitate agro-biotechnological procedures to improve AM colonization and/or efficiency.

Automated summary

Plant-microorganism interactions at the rhizosphere level greatly influence plant growth and its tolerance or resistance to various stresses. The cooperation between plant roots and arbuscular mycorrhizal fungi is particularly important in forestry and agriculture, as about 80% of terrestrial plant species can form such a symbiotic relationship. Recent studies have revealed the regulatory mechanisms of AM symbiosis at the molecular level. This review summarizes these findings and highlights the molecular players and signaling pathways involved in the regulation of AM symbiosis.