Phytochrome control of the tms2 gene in transgenic Arabidopsis: a strategy for selecting mutants in the signal transduction pathway.
Phytochrome control of the tms2 gene in transgenic Arabidopsis: a strategy for selecting mutants in the signal transduction pathway.
复制标题
转基因拟南芥中 tms2 基因的光敏色素控制：选择信号转导途径突变体的策略。
DOI：
10.1105/tpc.3.6.573
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Tobin,EM
中科院分区：
文献类型：
--
作者：
Karlin-Neumann,GA;Brusslan,JA;Tobin,EM
将根癌农杆菌的tms2基因导入拟南芥，产生具有新的可选择表型的转基因幼苗：幼苗在微摩尔浓度的生长素酰胺底物上生长受到强烈抑制，而对野生型幼苗没有显著影响。tms2基因编码一种酰胺水解酶，该酶能催化无生物活性的生长素酰胺转化为活性的生长素，而活性生长素在高浓度时对植物是有毒的。在缺乏外源底物的情况下，tms2+转基因幼苗生长正常且可育。当生长在生长素酰胺上时，黄化和绿色tms2+幼苗都表现出多种剂量依赖性的生长素毒性效应。tms2 mRNA和编码的氨基水解酶活性在转基因拟南芥中均可检测到，但在野生型拟南芥中未检测到，这表明野生型拟南芥缺乏同源活性。此外，当引入的tms2基因融合到拟南芥cab140启动子中时，tms2 RNA及其编码的氨基水解酶活性，从而通过光敏色素作用调节条件致死表型。因此，tms2基因可以作为拟南芥中可调节的选择性标记，用于分离失去tms2基因活性调节的反调节突变体。
Introduction of the tms2 gene from Agrobacterium tumefaciens into Arabidopsis thaliana yields transgenic seedlings with a new selectable phenotype: the seedlings are strongly growth inhibited on micromolar concentrations of auxin amide substrates that do not significantly affect wild-type seedlings. The tms2 gene encodes an amidohydrolase that catalyzes the conversion of biologically inactive auxin amides into active auxins, which are toxic to plants at elevated concentrations. In the absence of exogenous substrate, tms2+transgenic seedlings grow normally and are fertile. When grown on auxin amides, both etiolated and green tms2+seedlings exhibit a variety of dose-dependent auxin toxicity effects. tms2 mRNA and the encoded amidohydrolase activity are both detectable in transgenic but not in wild-type seedlings, demonstrating that a cognate activity is lacking in wild-type Arabidopsis. Furthermore, when the introduced tms2 gene is fused to the Arabidopsis cab140 promoter, the tms2 RNA and its encoded amidohydrolase activity and, thus, the conditional lethal phenotype can be modulated by phytochrome action. The tms2 gene can, therefore, serve as a regulatable selectable marker in Arabidopsis that should be useful in isolation of trans-regulatory mutants that have lost the imposed regulation of tms2 gene activity.