Wounding of Arabidopsis halleri leaves enhances cadmium accumulation that acts as a defense against herbivory

The Author(s) 2015. This article is published with open access at Springerlink.com Abstract Approximately 0.2 % of all angiosperms are classified as metal hyperaccumulators based on their extraordinarily high leaf metal contents, for example [1 % zinc, [0.1 % nickel or [0.01 % cadmium (Cd) in dry biomass. So far, metal hyperaccumulation has been considered to be a taxon-wide, constitutively expressed trait, the extent of which depends solely on available metal concen-trations in the soil. Here we show that in the facultative metallophyte Arabidopsis halleri, both insect herbiv-ory and mechanical wounding of leaves trigger an increase specifically in leaf Cd accumulation. Moreover, the Cd concentrations accumulated in leaves can serve as an elemental defense agains