TY - JOUR
T1 - The tonoplast-localized transporter OsHMA3 plays an important role in maintaining Zn homeostasis in rice
AU - Cai, Hongmei
AU - Huang, Sheng
AU - Che, Jing
AU - Yamaji, Naoki
AU - Ma, Jian Feng
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Specially Promoted Research (JSPS KAKENHI grant no. 16H06296 to JFM). We also acknowledge the National Key Research and Development Program of
Funding Information:
China (2016YFD0200108) and the China Scholarship Council for funding this work.
Publisher Copyright:
© 2019 The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Experimental Biology.
PY - 2019/5
Y1 - 2019/5
N2 - In order to respond to fluctuating zinc (Zn) in the environment, plants must have a system to control Zn homeostasis. However, how plants maintain an appropriate level of Zn during their growth and development is still poorly understood. In this study, we found that OsHMA3, a tonoplast-localized transporter for Zn/Cd, plays an important role in Zn homeostasis in rice. Accessions with the functional allele of OsHMA3 showed greater tolerance to high Zn than those with the non-functional allele based on root elongation test. A 67Zn-labeling experiment showed that accessions with loss of function of OsHMA3 had lower Zn accumulation in the roots but similar concentrations in the shoots compared with functional OsHMA3 accessions. When exposed to Zn-free growing medium, the concentration in the root cell sap was rapidly decreased in accessions with functional OsHMA3, but less dramatic changes were observed in non-functional accessions. A mobility experiment showed that more Zn in the roots was translocated to the shoots in accessions with functional OsHMA3. Higher expression levels of OsZIP4, OsZIP5, OsZIP8, and OsZIP10 were found in the roots of accessions with functional OsHMA3 in response to Zn deficiency. Taken together, our results indicate that OsHMA3 plays an important role in rice roots in both Zn detoxification and storage by sequestration into the vacuoles, depending on Zn concentration in the environment.
AB - In order to respond to fluctuating zinc (Zn) in the environment, plants must have a system to control Zn homeostasis. However, how plants maintain an appropriate level of Zn during their growth and development is still poorly understood. In this study, we found that OsHMA3, a tonoplast-localized transporter for Zn/Cd, plays an important role in Zn homeostasis in rice. Accessions with the functional allele of OsHMA3 showed greater tolerance to high Zn than those with the non-functional allele based on root elongation test. A 67Zn-labeling experiment showed that accessions with loss of function of OsHMA3 had lower Zn accumulation in the roots but similar concentrations in the shoots compared with functional OsHMA3 accessions. When exposed to Zn-free growing medium, the concentration in the root cell sap was rapidly decreased in accessions with functional OsHMA3, but less dramatic changes were observed in non-functional accessions. A mobility experiment showed that more Zn in the roots was translocated to the shoots in accessions with functional OsHMA3. Higher expression levels of OsZIP4, OsZIP5, OsZIP8, and OsZIP10 were found in the roots of accessions with functional OsHMA3 in response to Zn deficiency. Taken together, our results indicate that OsHMA3 plays an important role in rice roots in both Zn detoxification and storage by sequestration into the vacuoles, depending on Zn concentration in the environment.
KW - OsHMA3
KW - ZIP transporter
KW - Zn distribution
KW - Zn root-to-shoot mobility
KW - Zn tolerance
KW - vacuolar sequestration
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U2 - 10.1093/jxb/erz091
DO - 10.1093/jxb/erz091
M3 - Article
C2 - 30840766
AN - SCOPUS:85065825399
SN - 0022-0957
VL - 70
SP - 2717
EP - 2725
JO - Journal of experimental botany
JF - Journal of experimental botany
IS - 10
ER -