Metabolic engineering of isoflavonoid biosynthesis in alfalfa
Metabolic engineering of isoflavonoid biosynthesis in alfalfa
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DOI：
10.1104/pp.105.062539
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发表时间：
2005-08-01
期刊：
影响因子：
7.4
通讯作者：
Dixon, RA
中科院分区：
文献类型：
--
作者：
Deavours, BE;Dixon, RA
饮食异黄酮的潜在健康益处引起了对这些植物雌激素合成植物的综合兴趣。仿生木黄酮葡萄糖剂的产生（P至50 nmol G 21新鲜重量）是在苜蓿（Medicago sativa）叶片中设计的，该叶片是通过Medicago truncatula（MTIFS1）的组成型异黄酮合酶的组成型表达。生物氨酸A（4'-O-甲基酶蛋白酶）和pratensensin（3'-羟基苯胺A）的葡萄糖剂也积累。尽管MTIFS1在所有检查的器官中都高度表达，但染料木黄酮的积累仅限于叶子。 MTIFS1表达的线累积了几种其他异黄酮，包括formononetin和daidzein，以响应UV-B或Phoma Medicaginis，而这些化合物的Chalcone和Flavanone前体累积在控制线中。在表达MTIFS1的植物的植物性疟原虫感染的叶片中观察到了植物甲甲霉素的积累增强。微阵列分析表明MTIFS1表达不会显着改变叶片中的全局基因表达。我们的结果突出了与植物天然产物的代谢工程相关的一些挑战，包括组织特异性积累，通过内源性酶活性进一步修饰的潜力（羟基化，甲基化和糖基化）以及工厂对环境因素的差异反应。
The potential health benefits of dietary isoflavones have generated considerable interest in engineering the synthesis of these phytoestrogens into plants. Genistein glucoside production ( p to 50 nmol g 21 fresh weight) was engineered in alfalfa (Medicago sativa) leaves by constitutive expression of isoflavone synthase from Medicago truncatula (MtIFS1). Glucosides of biochanin A (4'-O-methylgenistein) and pratensein (3'-hydroxybiochanin A) also accumulated. Although MtIFS1 was highly expressed in all organs examined, genistein accumulation was limited to leaves. MtIFS1-expressing lines accumulated several additional isoflavones, including formononetin and daidzein, in response to UV-B or Phoma medicaginis, whereas the chalcone and flavanone precursors of these compounds accumulated in control lines. Enhanced accumulation of the phytoalexin medicarpin was observed in P. medicaginis-infected leaves of MtIFS1-expressing plants. Microarray profiling indicated that MtIFS1 expression does not significantly alter global gene expression in the leaves. Our results highlight some of the challenges associated with metabolic engineering of plant natural products, including tissue-specific accumulation, potential for further modification by endogenous enzyme activities (hydroxylation, methylation, and glycosylation), and the differential response of engineered plants to environmental factors.