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Differential expression and regulation of iron‐regulated metal transporters in Arabidopsis halleri and Arabidopsis thaliana – the role in zinc tolerance
Author(s) -
Shanmugam Varanavasiappan,
Lo JingChi,
Wu ChiaLin,
Wang ShanLi,
Lai ChongCheong,
Connolly Erin L.,
Huang JingLing,
Yeh KuoChen
Publication year - 2011
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2010.03606.x
Subject(s) - arabidopsis thaliana , hyperaccumulator , arabidopsis , zinc , biology , iron deficiency , shoot , transporter , homeostasis , iron homeostasis , atp binding cassette transporter , microbiology and biotechnology , botany , phytoremediation , gene , biochemistry , chemistry , mutant , ecology , medicine , organic chemistry , contamination , anemia
Summary• To avoid zinc (Zn) toxicity, plants have developed a Zn homeostasis mechanism to cope with Zn excess in the surrounding soil. In this report, we uncovered the difference of a cross‐homeostasis system between iron (Fe) and Zn in dealing with Zn excess in the Zn hyperaccumulator Arabidopsis halleri ssp. gemmifera and nonhyperaccumulator Arabidopsis thaliana . • Arabidopsis halleri shows low expression of the Fe acquisition and deficiency response‐related genes IRT1 and IRT2 compared with A. thaliana . In A. thaliana , lowering the expression of IRT1 and IRT2 through the addition of excess Fe to the medium increases Zn tolerance. • Excess Zn induces significant Fe deficiency in A. thaliana and reduces Fe accumulation in shoots. By contrast, the accumulation of Fe in shoots of A. halleri was stable under various Zn treatments. Root ferric chelate reductase (FRO) activity and expression of FIT are low in A. halleri compared with A. thaliana. Overexpressing a ZIP family member IRT3 in irt1‐1, rescues the Fe‐deficient phenotype. • A fine‐tuned Fe homeostasis mechanism in A. halleri maintains optimum Fe level by Zn‐regulated ZIP transporters and prevents high Zn uptake through Fe‐regulated metal transporters, and in part be responsible for Zn tolerance.