Cadmium for all meals – plants with an unusual appetite

Abstract

Since the beginning of the Bronze Age the acquisition of metals and the mastering of metal processing has been a driving force in human civilisation. It is difficult to imagine, however, how a plant could possibly profit from accumulating excessive amounts of a metal for which there is no metabolic need. Leaving behind an environmentally degraded wasteland, human mining and smeltering activities contributed to providing the niches for such plants, sometimes even accomplishing seed dispersal – through seeds attached to the boots of migrating miners. A stunning example of this is found in the healthy populations of Thlaspi caerulescens in the Cevennes (southern France), the leaves of which have been found to contain the toxic and non-essential metal cadmium (Cd) at concentrations between 1000 and 3000 mg kg⁻¹ dry biomass (R. D. Reeves, unpublished). In this issue, experiments under controlled experimental and glasshouse conditions are reported, confirming an extraordinary level of Cd accumulation and tolerance in these populations (Lombi et al., pp. 11–20).