OsZIP4, a novel zinc-regulated zinc transporter in rice.
Zinc (Zn) is an essential element for the normal growth of plants but information is scarce on the mechanisms whereby Zn is transported in rice (Oryza sativa L.) plants. Four distinct genes, OsZIP4, OsZIP5, OsZIP6, and OsZIP7 that exhibit sequence similarity to the rice ferrous ion transporter, OsIRT1, were isolated. Microarray and northern blot analysis revealed that OsZIP4 was highly expressed under conditions of Zn deficiency in roots and shoots. Real-time-PCR revealed that the OsZIP4 transcripts were more abundant than those of OsZIP1 or OsZIP3 in Zn-deficient roots and shoots. OsZIP4 complemented a Zn-uptake-deficient yeast (Saccharomyces cerevisiae) mutant, Deltazrt1,Deltazrt2, indicating that OsZIP4 is a functional transporter of Zn. OsZIP4-synthetic green fluorescent protein (sGFP) fusion protein was transiently expressed in onion epidermal cells localized to the plasma membrane. In situ hybridization analysis revealed that OsZIP4 in Zn-deficient rice was expressed in shoots and roots, especially in phloem cells. Furthermore, OsZIP4 transcripts were detected in the meristem of Zn-deficient roots and shoots. These results suggested that OsZIP4 is a Zn transporter that may be responsible for the translocation of Zn within rice plants.
Ishimaru
Yasuhiro
Y
Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Science, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Suzuki
Motofumi
M
Kobayashi
Takanori
T
Takahashi
Michiko
M
Nakanishi
Hiromi
H
Mori
Satoshi
S
Nishizawa
Naoko K
NK
D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D005816:Genetic Complementation Test; D018519:Meristem / Q000378:metabolism; D046228:Microarray Analysis; D005810:Multigene Family / Q000235:genetics; D019697:Onions / Q000166:cytology / Q000235:genetics; D012275:Oryza / Q000033:anatomy & histology / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D015032:Zinc / Q000378:metabolism
D002352:Carrier Proteins; D027682:Cation Transport Proteins; D010940:Plant Proteins; C017800:zinc-binding protein; D015032:Zinc