Root-secreted nicotianamine from Arabidopsis halleri facilitates zinc hypertolerance by regulating zinc bioavailability

Heavy metal hyperaccumulators grow endemically on metal-rich soils and exhibit extraordinarily high metal tolerance. Arabidopsis halleri, one of 500 found heavy metal hyperaccumulators in the world, is recognized as a zinc hyperaccumulator. In this study, we first discover that nicotianamine is secreted from the root of A. halleri and functions as a zinc chelator to regulate zinc availability in the rhizosphere for uptake. The secretion is zinc regulated and directly related to excess zinc tolerance.
Kuo-Chen Yeh

M. Tsednee, S.-C. Yang, D.-C. Lee and K.-C. Yeh * (2014) Root-secreted nicotianamine from Arabidopsis halleri facilitates zinc hypertolerance by regulating zinc bioavailability Plant Physiology