Opinion: Non-mycorrhizal Plants: The exceptions that prove the rule (TIPS)

Most vascular plants establish in their roots a multifunctional symbiosis with arbuscular mycorrhizal (AM) fungi. Among the 29% that do not host AM fungi are 66-92% of the members of the Brassicaceae family, including some major crops (broccoli, oilseed rape) as well as the model plant Arabidopsis thaliana. Although Arabidopsis is considered a non-host, conditional and rudimentary AM colonization has been described in it. In this review, Cosme et al. indicate that the existing (and extensive) genomic information from the Brassicaceae family may shed light on the factors that drive AM symbiotic incompatibility, based on the presence or absence of symbiotic toolkit genes (NFP, DMI2, DMI3, CASTOR and others) required for colonization and establishment of the arbuscules. (Summary by Isabel Mendoza) Trends Plant Sci. 10.1016/j.tplants.2018.04.004