Elevated production of melatonin in transgenic rice seeds expressing rice tryptophan decarboxylase
Elevated production of melatonin in transgenic rice seeds expressing rice tryptophan decarboxylase
复制标题
DOI：
10.1111/jpi.12120
复制
发表时间：
2014-04-01
影响因子：
10.3
通讯作者：
Back, Kyoungwhan
中科院分区：
文献类型：
--
作者：
Byeon, Yeong;Park, Sangkyu;Back, Kyoungwhan
植物生物技术的一个主要目标是通过代谢工程来改善作物的营养品质。褪黑激素是一种众所周知的生物活性分子，具有一系列促进健康的特性，包括强大的抗氧化能力。为了产生富含褪黑激素的水稻植株，我们首先在水稻基因组中独立地过表达三个色氨酸脱羧酶同基因。通过过度表达TDC 1、TDC 2和TDC 3，转基因品系中的褪黑激素水平发生了改变; TDC 3转基因种子（TDC 3 -1）的褪黑激素浓度是野生型种子的31倍。然而，在TDC 3转基因幼苗中，褪黑激素含量仅比野生型水平增加一倍。因此，种子特异性的褪黑激素积累似乎发生在TDC 3转基因株系中。除了增加褪黑激素含量，TDC 3转基因株系还具有增强的褪黑激素中间体水平，包括5-羟色氨酸、色胺、血清素和N-乙酰血清素。与此相反，褪黑激素生物合成mRNA的表达水平并没有增加在TDC 3转基因株系，表明褪黑激素及其中间体在这些株系中的增加完全归因于TDC 3基因的过表达。
A major goal of plant biotechnology is to improve the nutritional qualities of crop plants through metabolic engineering. Melatonin is a well-known bioactive molecule with an array of health-promoting properties, including potent antioxidant capability. To generate melatonin-rich rice plants, we first independently overexpressed three tryptophan decarboxylase isogenes in the rice genome. Melatonin levels were altered in the transgenic lines through overexpression of TDC1, TDC2, and TDC3; TDC3 transgenic seed (TDC3-1) had melatonin concentrations 31-fold higher than those of wild-type seeds. In TDC3 transgenic seedlings, however, only a doubling of melatonin content occurred over wild-type levels. Thus, a seed-specific accumulation of melatonin appears to occur in TDC3 transgenic lines. In addition to increased melatonin content, TDC3 transgenic lines also had enhanced levels of melatonin intermediates including 5-hydroxytryptophan, tryptamine, serotonin, and N-acetylserotonin. In contrast, expression levels of melatonin biosynthetic mRNA did not increase in TDC3 transgenic lines, indicating that increases in melatonin and its intermediates in these lines are attributable exclusively to overexpression of the TDC3 gene.