TY - JOUR
T1 - Mutation of a nitrate transporter, AtNRT1:4, results in a reduced petiole nitrate content and altered leaf development
AU - Chiu, Chi Chou
AU - Lin, Choun Sea
AU - Hsia, An Ping
AU - Su, Ruey Chih
AU - Lin, Huey Ling
AU - Tsay, Yi Fang
N1 - Funding Information:
We thank the Arabidopsis Knockout Facility (University of Wisconsin, Madison, WI, U.S.A.) for providing T-DNA knockout resources. This work was supported by the Institute of Molecular Biology, Academia Sinica, Taiwan, and by an NSC grant (92-2321-B-001-007) to Y.-F.T.
PY - 2004/9
Y1 - 2004/9
N2 - Unlike nitrate uptake of plant roots, less is known at the molecular level about how nitrate is distributed in various plant tissues. In the present study, characterization of the nitrate transporter, AtNRT1:4, revealed a special role of petiole in nitrate homeostasis. Electrophysiological studies using Xenopus oocytes showed that AtNRT1:4 was a low-affinity nitrate transporter. Whole-mount in situ hybridization and RT-PCR demonstrated that AtNRT1:4 was expressed in the leaf petiole. In the wild type, the leaf petiole had low nitrate reductase activity, but a high nitrate content, indicating that it is the storage site for nitrate, whereas, in the atnrt1:4 mutant, the petiole nitrate content was reduced to 50-64% of the wild-type level. Moreover, atnrt1:4 mutant leaves were wider than wild-type leaves. This study revealed a critical role of AtNRT1:4 in regulating leaf nitrate homeostasis, and the deficiency of AtNRT1: 4 can alter leaf development.
AB - Unlike nitrate uptake of plant roots, less is known at the molecular level about how nitrate is distributed in various plant tissues. In the present study, characterization of the nitrate transporter, AtNRT1:4, revealed a special role of petiole in nitrate homeostasis. Electrophysiological studies using Xenopus oocytes showed that AtNRT1:4 was a low-affinity nitrate transporter. Whole-mount in situ hybridization and RT-PCR demonstrated that AtNRT1:4 was expressed in the leaf petiole. In the wild type, the leaf petiole had low nitrate reductase activity, but a high nitrate content, indicating that it is the storage site for nitrate, whereas, in the atnrt1:4 mutant, the petiole nitrate content was reduced to 50-64% of the wild-type level. Moreover, atnrt1:4 mutant leaves were wider than wild-type leaves. This study revealed a critical role of AtNRT1:4 in regulating leaf nitrate homeostasis, and the deficiency of AtNRT1: 4 can alter leaf development.
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U2 - 10.1093/pcp/pch143
DO - 10.1093/pcp/pch143
M3 - Article
C2 - 15509836
AN - SCOPUS:7944225483
SN - 0032-0781
VL - 45
SP - 1139
EP - 1148
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
IS - 9
ER -