Evolutionary changes in defensive specialized metabolism in the genus Hordeum

Dramatic metabolic changes were shown to have occurred after the separation of the H/Xu clades from the I/Xa clades in the genus Hordeum. In the lineage leading to the H/Xu clades, defensive specialized metabolites, benzoxazinones, were replaced by gramine and dehydrodimers of hydroxycinnamic acid amides such as hordatines and murinamides.178