Imamura Tomohiro, Koga Hironori, Miyazato Akio, Xu Zhe, Shigehisa Ryouta, Ohki Shinya, Mori Masashi
Department of Bioproduction Science, Ishikawa Prefectural University.
Center for Nano Materials and Technology (CNMT), Japan Advanced Institute of Science and Technology (JAIST).
Plant Biotechnol (Tokyo). 2025 Jun 25;42(2):111-119. doi: 10.5511/plantbiotechnology.25.0122a.
Betalain pigments, primarily produced by the order Caryophyllales, are categorized into betacyanins (red/purple) and betaxanthins (yellow/orange). While the biosynthetic pathways of these pigments are well-studied, the genes responsible for betaxanthin biosynthesis in quinoa were previously unknown. This study identified three candidate genes, , , and , as quinoa orthologs of beet and . Agroinfiltration experiments in revealed that exhibited L-DOPA synthesis activity, whereas did not. To enable large-scale production of betaxanthins, we developed a tobacco BY-2 cell line expressing and , with vulgaxanthin I identified as the predominant product. Furthermore, the betaxanthin mixture extracted from this line inhibited amyloid-β (Aβ) aggregation, a key factor associated with Alzheimer's disease. These findings demonstrate the potential of betaxanthins derived from quinoa betaxanthin-biosynthesis genes for applications in health supplements and pharmaceuticals.
甜菜色素主要由石竹目植物产生，分为甜菜青素（红色/紫色）和甜菜黄素（黄色/橙色）。虽然这些色素的生物合成途径已得到充分研究，但藜麦中负责甜菜黄素生物合成的基因此前尚不清楚。本研究鉴定出三个候选基因，即 、 和 ，作为甜菜 和 的藜麦直系同源基因。在 中的农杆菌浸润实验表明， 具有L - 多巴合成活性，而 则没有。为了实现甜菜黄素的大规模生产，我们开发了一种表达 和 的烟草BY - 2细胞系，其中已鉴定出紫黄质I为主要产物。此外，从该细胞系中提取的甜菜黄素混合物抑制了淀粉样β蛋白（Aβ）聚集，而Aβ聚集是与阿尔茨海默病相关的关键因素。这些发现证明了源自藜麦甜菜黄素生物合成基因的甜菜黄素在健康补充剂和药物应用中的潜力。
