A mutation in the Arabidopsis KT2/KUP2 potassium transporter gene affects shoot cell expansion
A mutation in the Arabidopsis KT2/KUP2 potassium transporter gene affects shoot cell expansion
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DOI：
10.1105/tpc.010322
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发表时间：
2002-01-01
期刊：
影响因子：
11.6
通讯作者：
Reed, JW
中科院分区：
文献类型：
--
作者：
Elumalai, RP;Nagpal, P;Reed, JW
钾离子（K+）是植物中含量最丰富的阳离子，是细胞生长所必需的。拟南芥shy 3 -1突变体具有短的下胚轴、小的叶子和短的花茎，这些缺陷是由于细胞扩增减少所致。半显性shy 3 -1突变改变了KT 2/KUP 2中的一个氨基酸，KUP 2是一种与大肠杆菌Kup蛋白相关的K+转运蛋白。KT 2/KUP 2/SHY 3基因的第二个突变，包括假定的无效突变，抑制了shy 3 -1表型。具有这些基因内抑制突变的植物看起来与野生型植物相似，这表明KT 2/KUP 2/SHY 3与其他基因冗余地起作用。在野生型植物中表达KT 2/KUP 2/SHY 3的shy 3 -1突变体版本赋予shy 3 -1样表型，表明shy 3 -1可能导致功能获得或产生干扰蛋白。shy 3 -1突变并不消除KT 2/KUP 2 cDNA拯救钾转运缺陷型大肠杆菌生长的能力。大肠杆菌突变株。P-SHY 3：：GUS融合体在植物的生长部分中表达。这些结果表明，KT 2/KUP 2/SHY 3介导生长组织中K+依赖性细胞扩增。
Potassium ions (K+) are the most abundant cations in plants and are necessary for cell growth. Arabidopsis shy3-1 mutant plants have a short hypocotyl, small leaves, and a short flowering stem, and these defects result from decreased cell expansion. The semidominant shy3-1 mutation changes an amino acid in KT2/KUP2, a K+ transporter related to the Escherichia coli Kup protein. Second mutations in the KT2/KUP2/SHY3 gene, including presumed null mutations, suppress the shy3-1 phenotypes. Plants with these intragenic suppressor mutations appear similar to wild-type plants, suggesting that KT2/KUP2/SHY3 acts redundantly with other genes. Expression of the shy3-1 mutant version of KT2/KUP2/SHY3 in wild-type plants confers shy3-1-like phenotypes, indicating that shy3-1 probably either causes a gain of function or creates an interfering protein. The shy3-1 mutation does not eliminate the ability of the KT2/KUP2 cDNA to rescue the growth of a potassium transport-deficient E. coli mutant. A P-SHY3::GUS fusion is expressed in growing portions of the plant. These results suggest that KT2/KUP2/SHY3 mediates K+-dependent cell expansion in growing tissues.