Arbuscular mycorrhizal fungi: effects on plant terpenoid accumulation

Arbuscular mycorrhizal fungi (AMF) are a diverse group of soil dwelling fungi that form symbiotic associations with land plants. AMF-plant associations promote the accumulation of plant terpenoids beneficial to human health, although how AMF mediate terpenoid accumulation is not fully understood. A critical assessment and discussion of the literature relating to mechanisms by which AMF influence plant terpenoid accumulation, and whether this symbiosis can be harnessed in horticultural ecosystems was performed. Modification of plant morphology, phosphorus availability, and gene transcription involved with terpenoid biosynthetic pathways were identified as key mechanisms associated with terpenoid accumulation in AMF-colonised plants. In order to exploit AMF-plant symbioses in horticultural ecosystems it is important to consider the specificity of the AMF-plant association, the predominant factor affecting terpenoid accumulation, as well as the end-use application of the harvested plant material. Future research should focus on resolving the relationship between ecologically-matched AMF genotypes and terpenoid accumulation in plants to establish if these associations are effective at promoting mechanisms favourable for plant terpenoid accumulation.