Mutation of a nitrate transporter, AtNRT1:4, results in a reduced petiole nitrate content and altered leaf development
Mutation of a nitrate transporter, AtNRT1:4, results in a reduced petiole nitrate content and altered leaf development
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DOI：
10.1093/pcp/pch143
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发表时间：
2004-09-01
影响因子：
4.9
通讯作者：
Tsay, YF
中科院分区：
文献类型：
--
作者：
Chiu, CC;Lin, CS;Tsay, YF
与植物根对硝酸盐的吸收不同，在分子水平上对硝酸盐在植物各种组织中的分布知之甚少。在本研究中，对硝酸盐转运蛋白AtNRT1：4的研究揭示了叶柄在硝酸盐稳态中的特殊作用。非洲爪哇卵母细胞的电生理研究表明，AtNRT1：4是一种低亲和力的硝酸盐转运蛋白。整装原位杂交和RT-PCR结果表明，AtNRT1：4在叶柄中有表达。野生型叶片的硝酸还原酶活性较低，但硝酸盐含量较高，是硝酸盐的储存部位，而在atnrt1：4突变体中，叶柄硝酸盐含量下降到野生型的50-。此外，atnrt1：4突变体叶宽大于野生型。本研究揭示了AtNRT1：4在调节叶片硝酸盐动态平衡中的重要作用，AtNRT1：4的缺失可以改变叶片的发育。
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.