The eXtreme plant bona fides of Arabidopsis lyrata stem from its preference for sandy, gravelly, rocky or chasmophytic “soil”. At the molecular level, its value has been greatest for its contribution to understanding of mechanisms of mutation, selection and genome-size transformations in plants.
Schrenkiella parvula – a 7 chromosome member of the Brassicaceae – has an eXtreme ability, in the natural world, to function in the hypersaline conditions surrounding Lake Tuz in central Anatolia, Turkey. It is also notable for its tolerance of high levels of other cations, especially Li+ and Mg2+ and of Boron. These extreme adaptations were central to the initial decision to sequence the genome of this species.
E. salsugineum (formerly Thellungiella salsuginea) was originally selected as a model organism because of its ability, in the natural world, to function in saline, cold, and freezing conditions, and for its efficient mobilization of resources in poor or degraded soils.