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Abstract：
BACKGROUND: Betalains are reddish and yellow pigments that accumulate in a few plant species of the order Caryophyllales. These pigments have antioxidant and medicinal properties and can be used as functional foods. They also enhance resistance to stress or disease in crops. Several plant species belonging to other orders have been genetically engineered to express betalain pigments. Betalains can also be used for flower color modification in ornamental plants, as they confer vivid colors, like red and yellow. To date, betalain engineering to modify the color of Torenia fournieri-or wishbone flower-a popular ornamental plant, has not been attempted.
RESULTS: We report the production of purple-reddish-flowered torenia plants from the purple torenia cultivar \"Crown Violet.\" Three betalain-biosynthetic genes encoding CYP76AD1, dihydroxyphenylalanine (DOPA) 4,5-dioxygenase (DOD), and cyclo-DOPA 5-O-glucosyltransferase (5GT) were constitutively ectopically expressed under the cauliflower mosaic virus (CaMV) 35S promoter, and their expression was confirmed by quantitative real-time PCR (qRT-PCR) analysis. The color traits, measured by spectrophotometric colorimeter and spectral absorbance of fresh petal extracts, revealed a successful flower color modification from purple to reddish. Red pigmentation was also observed in whole plants. LC-DAD-MS and HPLC analyses confirmed that the additional accumulated pigments were betacyanins-mainly betanin (betanidin 5-O-glucoside) and, to a lesser extent, isobetanin (isobetanidin 5-O-glucoside). The five endogenous anthocyanins in torenia flower petals were also detected.
CONCLUSIONS: This study demonstrates the possibility of foreign betacyanin accumulation in addition to native pigments in torenia, a popular garden bedding plant. To our knowledge, this is the first report presenting engineered expression of betalain pigments in the family Linderniaceae. Genetic engineering of betalains would be valuable in increasing the flower color variation in future breeding programs for torenia.
RESULTS: We report the production of purple-reddish-flowered torenia plants from the purple torenia cultivar \"Crown Violet.\" Three betalain-biosynthetic genes encoding CYP76AD1, dihydroxyphenylalanine (DOPA) 4,5-dioxygenase (DOD), and cyclo-DOPA 5-O-glucosyltransferase (5GT) were constitutively ectopically expressed under the cauliflower mosaic virus (CaMV) 35S promoter, and their expression was confirmed by quantitative real-time PCR (qRT-PCR) analysis. The color traits, measured by spectrophotometric colorimeter and spectral absorbance of fresh petal extracts, revealed a successful flower color modification from purple to reddish. Red pigmentation was also observed in whole plants. LC-DAD-MS and HPLC analyses confirmed that the additional accumulated pigments were betacyanins-mainly betanin (betanidin 5-O-glucoside) and, to a lesser extent, isobetanin (isobetanidin 5-O-glucoside). The five endogenous anthocyanins in torenia flower petals were also detected.
CONCLUSIONS: This study demonstrates the possibility of foreign betacyanin accumulation in addition to native pigments in torenia, a popular garden bedding plant. To our knowledge, this is the first report presenting engineered expression of betalain pigments in the family Linderniaceae. Genetic engineering of betalains would be valuable in increasing the flower color variation in future breeding programs for torenia.
摘要：
背景：Betalains是红色和黄色色素，在石竹目的一些植物物种中积累。这些色素具有抗氧化和药用特性，可用作功能性食品。它们还增强了作物对压力或疾病的抵抗力。属于其他目的的几种植物物种已被基因工程改造以表达甜菜碱色素。Betalains也可用于观赏植物的花朵颜色修饰，因为它们赋予了生动的色彩，像红色和黄色。迄今为止,betalain工程，以修改Toreniafournieri或叉骨花的颜色-一种流行的观赏植物，尚未尝试。
结果：我们报告了从紫色紫罗兰品种“皇冠紫罗兰”生产的紫色带红色花的紫罗兰植物。\“三个甜菜碱生物合成基因编码CYP76AD1，二羟苯丙氨酸（DOPA）4,5-双加氧酶（DOD），和环多巴5-O-葡萄糖基转移酶（5GT）在花椰菜花叶病毒（CaMV）35S启动子下组成性异位表达，并通过定量实时PCR(qRT-PCR)分析证实它们的表达。颜色特征，通过分光光度比色计和新鲜花瓣提取物的光谱吸光度测量，揭示了一个成功的从紫色到带红色的花朵颜色修改。在整个植物中也观察到红色色素沉着。LC-DAD-MS和HPLC分析证实，额外积累的色素是β花青素-主要是β-苷（β-苷5-O-葡萄糖苷）和，在较小程度上，异甜菜碱（异甜菜碱5-O-葡萄糖苷）。还检测到了五花花瓣中的五种内源性花色苷。
结论：这项研究表明，除了在生育中的天然色素外，外来的β花青素积累的可能性，一种受欢迎的花园床上用品植物。据我们所知,这是第一份报告，介绍了在猪科中甜菜碱色素的工程表达。甜菜碱的基因工程在将来的花草育种计划中增加花的颜色变化方面将是有价值的。
结果：我们报告了从紫色紫罗兰品种“皇冠紫罗兰”生产的紫色带红色花的紫罗兰植物。\“三个甜菜碱生物合成基因编码CYP76AD1，二羟苯丙氨酸（DOPA）4,5-双加氧酶（DOD），和环多巴5-O-葡萄糖基转移酶（5GT）在花椰菜花叶病毒（CaMV）35S启动子下组成性异位表达，并通过定量实时PCR(qRT-PCR)分析证实它们的表达。颜色特征，通过分光光度比色计和新鲜花瓣提取物的光谱吸光度测量，揭示了一个成功的从紫色到带红色的花朵颜色修改。在整个植物中也观察到红色色素沉着。LC-DAD-MS和HPLC分析证实，额外积累的色素是β花青素-主要是β-苷（β-苷5-O-葡萄糖苷）和，在较小程度上，异甜菜碱（异甜菜碱5-O-葡萄糖苷）。还检测到了五花花瓣中的五种内源性花色苷。
结论：这项研究表明，除了在生育中的天然色素外，外来的β花青素积累的可能性，一种受欢迎的花园床上用品植物。据我们所知,这是第一份报告，介绍了在猪科中甜菜碱色素的工程表达。甜菜碱的基因工程在将来的花草育种计划中增加花的颜色变化方面将是有价值的。
