Identification and functional analysis of two ZIP metal transporters of the hyperaccumulator Thlaspi caerulescens
Identification and functional analysis of two ZIP metal transporters of the hyperaccumulator Thlaspi caerulescens
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DOI：
10.1007/s11104-009-0151-6
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发表时间：
2009-09
期刊：
影响因子：
4.9
通讯作者：
Jian Wu;F. Zhao;Artak Ghandilyan;B. Logoteta;Myriam Olortegui Guzman;H. Schat;Xiaowu Wang;Mark G. M. Aarts
中科院分区：
文献类型：
--
作者：
Jian Wu;F. Zhao;Artak Ghandilyan;B. Logoteta;Myriam Olortegui Guzman;H. Schat;Xiaowu Wang;Mark G. M. Aarts
The heavy metal hyperaccumulatorThlaspi caerulescensexpresses severalZIP-like genes at higher levels than their orthologues in non-hyperaccumulator species, but it is not clear why. To elucidate the function of theT. caerulescensorthologues of theArabidopsis thaliana ZIP5andZIP6genes, full-length cDNAs ofTcZNT5-LCandTcZNT6-LCwere cloned, their expression was examined and genes were expressed inA. thaliana. Transcript level analysis revealed the constitutively high expression of these two genes inT.caerulescenscompared toAtZIP5andAtZIP6genes and differential expression of both genes when comparing two accessions ofT. caerulescenswith different metal accumulation properties. Expression ofTcZNT5-LCinA. thalianadid not modify Cd or Zn tolerance, but mildly affected the root and shoot Zn concentrations towards a hyperaccumulator shoot to root concentration ratio.A. thaliana zip5knock-out mutants showed increased tolerance to Cd and decreased seed mineral concentrations. Expression ofTcZNT6-LCenhanced the Cd sensitivity ofA. thaliana, but no phenotype was observed for thezip6mutant. In conclusion, the changes in expression ofTcZNT5-LCandTcZNT6-LCupon changes in Zn or Cd exposure indicate both genes act in metal homeostasis, but their CaMV 35S-mediated expression inA. thalianadoes not createT. caerulescenshyperaccumulator phenotypes.
