Deng Yuan-Jie, Duan Ao-Qi, Liu Hui, Xu Zhi-Sheng, Xiong Ai-Sheng
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Ministry of Agriculture and Rural Affairs Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in East China, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
J Exp Bot. 2024 Dec 4;75(22):7202-7216. doi: 10.1093/jxb/erae351.
Capsanthin and capsorubin are red κ-xanthophylls exclusively found in a handful of other plant species. Currently, capsanthin and capsorubin are extracted from red pepper (Capsicum annuum L.). Here, high purity production of capsanthin and capsorubin was achieved in carrot (Daucus carota L.) taproot by a synthetic metabolic engineering strategy. Expression of a capsanthin-capsorubin synthase gene (CaCCS) from pepper resulted in dominant production of capsanthin, whereas expression of a LiCCS gene from tiger lily (Lilium lancifolium Thunb.) resulted in production of both capsanthin and capsorubin in carrot taproot. The highest content of capsanthin and capsorubin was obtained in LiC-1 carrot taproot hosting the LiCCS gene. Co-expression of DcBCH1 with CCS could improve the purity of capsanthin and capsorubin by eliminating the non-target carotenoids (e.g. α-carotene and β-carotene). The highest purity of capsanthin and capsorubin was obtained in BLiC-1 carrot taproot hosting DcBCH1+LiCCS genes, 91.10% of total carotenoids. The non-native pigments were esterified partially and stored in the globular chromoplast of carrot taproot. Our results demonstrated the use of carrot taproot as green factories for high purity production of capsanthin and capsorubin. The capsanthin/capsorubin carrot germplasms are also valuable materials for breeding colorful carrots cultivars.
辣椒红素和辣椒玉红素是仅在少数其他植物物种中发现的红色κ-叶黄素。目前，辣椒红素和辣椒玉红素是从红辣椒（辣椒）中提取的。在此，通过合成代谢工程策略在胡萝卜（胡萝卜）主根中实现了辣椒红素和辣椒玉红素的高纯度生产。来自辣椒的辣椒红素-辣椒玉红素合酶基因（CaCCS）的表达导致辣椒红素的优势生产，而来自卷丹（卷丹）的LiCCS基因的表达导致胡萝卜主根中同时产生辣椒红素和辣椒玉红素。在携带LiCCS基因的LiC-1胡萝卜主根中获得了最高含量的辣椒红素和辣椒玉红素。DcBCH1与CCS的共表达可以通过去除非目标类胡萝卜素（如α-胡萝卜素和β-胡萝卜素）来提高辣椒红素和辣椒玉红素的纯度。在携带DcBCH1+LiCCS基因的BLiC-1胡萝卜主根中获得了最高纯度的辣椒红素和辣椒玉红素，占总类胡萝卜素的91.10%。非天然色素部分酯化并储存在胡萝卜主根的球状有色体中。我们的结果证明了使用胡萝卜主根作为绿色工厂来高纯度生产辣椒红素和辣椒玉红素。辣椒红素/辣椒玉红素胡萝卜种质也是培育彩色胡萝卜品种的宝贵材料。
