Watanabe Sho, Ohtani Yuta, Tatsukami Yohei, Aoki Wataru, Amemiya Takashi, Sukekiyo Yasunori, Kubokawa Seiichi, Ueda Mitsuyoshi
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
Japan Society for the Promotion of Science , Sakyo-ku, Kyoto 606-8502, Japan.
J Agric Food Chem. 2017 Jun 14;65(23):4605-4610. doi: 10.1021/acs.jafc.7b01375. Epub 2017 Jun 6.
Folate is an important vitamin mainly ingested from vegetables, and folate deficiency causes various health problems. Recently, several studies demonstrated folate biofortification in plants or food crops by metabolic engineering through genetic modifications. However, the production and sales of genetically modified foods are under strict regulation. Here, we developed a new approach to achieve folate biofortification in spinach (Spinacia oleracea) without genetic modification. We hydroponically cultivated spinach with the addition of three candidate compounds expected to fortify folate. As a result of liquid chromatography tandem mass spectrometry analysis, we found that the addition of phenylalanine increased the folate content up to 2.0-fold (306 μg in 100 g of fresh spinach), representing 76.5% of the recommended daily allowance for adults. By measuring the intermediates of folate biosynthesis, we revealed that phenylalanine activated folate biosynthesis in spinach by increasing the levels of pteridine and p-aminobenzoic acid. Our approach is a promising and practical approach to cultivate nutrient-enriched vegetables.
叶酸是一种主要从蔬菜中摄取的重要维生素，叶酸缺乏会引发各种健康问题。最近，多项研究表明，通过基因改造进行代谢工程可实现植物或粮食作物中的叶酸生物强化。然而，转基因食品的生产和销售受到严格监管。在此，我们开发了一种新方法，可在不进行基因改造的情况下实现菠菜（Spinacia oleracea）中的叶酸生物强化。我们通过添加三种有望强化叶酸的候选化合物对菠菜进行水培。液相色谱串联质谱分析结果表明，添加苯丙氨酸可使叶酸含量提高至2.0倍（100克新鲜菠菜中含306微克），占成年人每日推荐摄入量的76.5%。通过测量叶酸生物合成的中间产物，我们发现苯丙氨酸通过提高蝶啶和对氨基苯甲酸的水平来激活菠菜中的叶酸生物合成。我们的方法是一种培育营养丰富蔬菜的有前景且实用的方法。
