Fe homeostasis based Zn tolerance in the Zn/Cd hyperaccumulator A. halleri

To avoid Zn toxicity, plants have developed a zinc (Zn) homeostasis mechanism to cope with Zn excess in the surrounding soil. We investigated a cross-homeostasis system of iron (Fe) and Zn in dealing with Zn excess in the Zn hyperaccumulator Arabidopsis halleri ssp. gemmifera and non-hyperaccumulator Arabidopsis thaliana. We found that excess Zn induced significant Fe deficiency in A. thaliana, but not in A. halleri. In A. halleri, the Fe-regulated metal transporters IRT1 and IRT2 are expressed at low level to prevent high uptake of Zn through these metal transporters that might be in part responsible for Zn tolerance.
Kuo-Chen Yeh