National Key Laboratory for Tropical Crops Breeding, Sanya, 572024, China.
Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Ministry of Agriculture, Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China.
Plant Cell Rep. 2024 Sep 20;43(10):235. doi: 10.1007/s00299-024-03318-4.
This study described the biosynthesis of 4-hydroxydihydrocinnamaldehyde sharing with monolignol pathway and supplemented the biosynthesis of colchicine in G. superba, 4-hydroxydihydrocinnamaldehyde produced in tobacco BY2 cells provided an important stepstone. The precursor, 4-hydroxydihydrocinnamaldehyde (4-HDCA), participates in the biosynthesis of the carbon skeleton of colchicine, which is derived from L-phenylalanine. However, one hypothesis proposed that 4-HDCA is synthesized by sharing the early part of the monolignol pathway in G. superba. In this study, we validated this prediction and identified the enzymatic functions involved in this pathway. GsDBR1 is a crucial enzyme to illustrate 4-HDCA diverging from monolignol pathway, we first confirmed its reductase activity on 4-coumaraldehyde, an important intermediate compound in monolignol biosynthesis. Then, the biochemical function of recombinant enzymes belonging to the other four families were verified to elucidate the entire process of 4-HDCA biosynthesis from L-phenylalanine. After reconstruction, the 4-HDCA was 78.4 ng/g with fresh weight (FW) of transgenic tobacco cells, and the yield increased to 168.22 ng/g·FW after improved treatment with methyl jasmonate (MeJA). The elucidation of 4-HDCA biosynthesis sharing the monolignol pathway supplemented the biosynthesis of colchicine in G. superba, and the production of 4-HDCA in tobacco cells provides an important step in the development of plant cell cultures as heterologous bio-factories for secondary metabolite production.
本研究描述了 4-羟基氢化肉桂醛的生物合成途径，该途径与木质素前体途径共享，并补充了藏红花中秋水仙碱的生物合成途径。烟草 BY2 细胞中产生的 4-羟基氢化肉桂醛为其提供了重要的前体物质。4-羟基氢化肉桂醛（4-HDCA）参与了秋水仙碱碳骨架的生物合成，而秋水仙碱的碳骨架则来源于 L-苯丙氨酸。然而，有一个假设认为 4-HDCA 是通过与藏红花中木质素前体途径的早期部分共享而合成的。在本研究中，我们验证了这一预测，并确定了参与该途径的酶的功能。GsDBR1 是一个关键酶，它阐明了 4-HDCA 从木质素途径分叉的过程，我们首先证实了它对 4-香豆醛的还原酶活性，4-香豆醛是木质素生物合成中的一个重要中间体化合物。然后，验证了属于其他四个家族的重组酶的生化功能，以阐明从 L-苯丙氨酸到 4-HDCA 生物合成的整个过程。在重建后，转基烟草细胞中的 4-HDCA 的含量为 78.4ng/g 鲜重（FW），用茉莉酸甲酯（MeJA）处理后，产量增加到 168.22ng/g·FW。4-HDCA 生物合成途径的阐明补充了藏红花中秋水仙碱的生物合成途径，而烟草细胞中 4-HDCA 的产生为植物细胞培养作为次生代谢产物生产的异源生物工厂的发展提供了重要的一步。
