1-deoxy-D-xylulose-5-phosphate synthase, a limiting enzyme for plastidic isoprenoid biosynthesis in plants
1-deoxy-D-xylulose-5-phosphate synthase, a limiting enzyme for plastidic isoprenoid biosynthesis in plants
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DOI：
10.1074/jbc.m100854200
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发表时间：
2001-06-22
影响因子：
4.8
通讯作者：
León, P
中科院分区：
文献类型：
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作者：
Estévez, JM;Cantero, A;León, P
产生异戊烯基二磷酸的质体2C-甲基-D-β 4-磷酸（MEP）途径的起始步骤由1-脱氧-D-木酮糖-5-磷酸合酶催化。为了研究1-脱氧-D-木酮糖-5-磷酸合酶是否催化植物MEP途径中的限制步骤，我们产生了过表达或低表达该酶的转基因拟南芥植物。与非转基因野生型植物相比，转基因植物积累不同水平的各种类异戊二烯，如叶绿素、生育酚、类胡萝卜素、脱落酸和赤霉素。表型上，转基因植物的生长和发芽率略有改变。由于几种质体类异戊二烯的水平与1-脱氧-D-木酮糖-5-磷酸合酶水平的变化相关，我们得出结论，这种酶催化MEP生物合成途径的限速步骤之一。此外，由于MEP途径的产物是异戊烯基二磷酸，我们的研究结果表明，在质体中的异戊烯基二磷酸池是限制isprenoid生产。
The initial step of the plastidic 2C-methyl-D-erythritol 4-phosphate (MEP) pathway that produces isopentenyl diphosphate is catalyzed by 1-deoxy-D-xylulose-5-phosphate synthase. To investigate whether or not 1-deoxy-D-xylulose-5-phosphate synthase catalyzes a limiting step in the MEP pathway in plants, we produced transgenic Arabidopsis plants that over- or underexpress this enzyme. Compared with non-transgenic wild-type plants, the transgenic plants accumulate different levels of various isoprenoids such as chlorophylls, tocopherols, carotenoids, abscisic acid, and gibberellins. Phenotypically, the transgenic plants had slight alterations in growth and germination rates. Because the levels of several plastidic isoprenoids correlate with changes in 1-deoxy-D-xylulose-5-phosphate synthase levels, we conclude that this enzyme catalyzes one of the rate-limiting steps of the MEP biosynthetic pathway. Furthermore, since the product of the MEP pathway is isopentenyl diphosphate, our results suggest that in plastids the pool of isopentenyl diphosphate is limiting to isprenoid production.