Dual-mycorrhizal plants: their ecology and relevance

TESTE, FRANÇOIS P.; DICKIE, IAN A.; JONES, MELANIE D.

NEW PHYTOLOGIST

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020 vol. 225 p. 1835 - 1851

0028-646X

Dual-mycorrhizal plants are capable of associating with fungi that form characteristic arbuscularmycorrhizal (AM) and ectomycorrhizal (EM) structures. Here, we address the followingquestions: (1) Howmany dual-mycorrhizal plant species are there? (2) What are the advantagesfor a plant to host two, rather than one, mycorrhizal types? (3) Which factors can provoke shiftsin mycorrhizal dominance (i.e. mycorrhizal switching)? We identify a large number (89 generawithin 32 families) of confirmed dual-mycorrhizal plants based on observing arbuscules or coilsforAMstatus and Hartig net or similar structures forEMstatus within the same plant species.Wethen review the possible nutritional benefits and discuss the possible mechanisms leading to netcosts and benefits. Cost and benefits of dual-mycorrhizal status appear to be context dependent,particularly with respect to the life stage of the host plant. Mycorrhizal switching occurs under awide range of abiotic and biotic factors, including soil moisture and nutrient status. The relevanceof dual-mycorrhizal plants in the ecological restoration of adverse sites where plants are notcarbon limited is discussed. We conclude that dual-mycorrhizal plants are underutilized inecophysiological-based experiments, yet are powerful model plant?fungal systems to betterunderstand mycorrhizal symbioses without confounding host effects.