Inoculation

Parasitism

Bacteria

Biology

Gene

Host (biology)

Nutrient

Mutualism (biology)

Abiotic component

Paleontology

Ecology

Immunology

Obligate

Arbuscular mycorrhizal fungi

Context (archaeology)

Arbuscular mycorrhizal

Abiotic stress

Symbiosis

Genetics

Biochemistry

Annual Review of Plant Biology

The symbiotic interaction between plants and arbuscular mycorrhizal (AM) fungi is often perceived as beneficial for both partners, though a large ecological literature highlights the context dependency of this interaction. Changes in abiotic variables, such as nutrient availability, can drive the interaction along the mutualism-parasitism continuum with variable outcomes for plant growth and fitness. However, AM fungi can benefit plants in more ways than improved phosphorus nutrition and plant growth. For example, AM fungi can promote abiotic and biotic stress tolerance even when considered parasitic from a nutrient provision perspective. Other than being obligate biotrophs, very little is known about the benefits AM fungi gain from plants. In this review, we utilize both molecular biology and ecological approaches to expand our understanding of the plant-AM fungal interaction across disciplines.

The Costs and Benefits of Plant–Arbuscular Mycorrhizal Fungal Interactions