Ni hyperaccumulators among North Caucasian plant species of the tribe Alysseae within the Brassicaceae family

Background. Heavy metals are dangerous industrial pollutants. The development of phytoremediation technologies based on plants having capability to hyperaccumulate heavy metals is a promising approach to detoxify polluted territories. Many such hyperaccumulators belong to the family Brassicaceae and are found mostly within the Alysseae tribe. We analyzed the molecular phylogeny and distribution of the ability to hyperaccumulate Ni within the tribe. Most of the Ni hyperaccumulators are related to the Odontarrhena section. We propose partitioning the tribes into five clades, whose compactness is illustrated by primary and secondary ITS2 structures characteristics.