Meng Geng, Clausen Sabine K, Rasmussen Søren K
Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
Plants (Basel). 2020 Mar 9;9(3):344. doi: 10.3390/plants9030344.
Black carrots are characterized by a significant amount of anthocyanins, which are not only a good source of natural food colorant, but can also provide many health benefits to humans. In the present work, taproots of different carrot genotypes were used to identify the candidate genes related to anthocyanin synthesis, with particular a focus on R2R3MYB, bHLH transcription factors, and glutathione S-transferase gene (). The RNA-sequencing analysis (RNA-Seq) showed that and had a genotypic dependent expression and they are likely involved in the regulation of anthocyanin biosynthesis. They were specifically upregulated in solid black taproots, including both black phloem and xylem. (LOC108204485) was upregulated in all black samples compared with the orange ones. We also found that (LOC108205254) might be an important anthocyanin transporter, and its upregulated expression resulted in the increasing of vacuolar anthocyanin accumulation in black samples. Moreover, high performance liquid chromatographic (HPLC) analysis and liquid chromatography coupled to mass spectrometry (LC-MS) were used to identify the individual anthocyanin in the purple tissues of two carrot cultivars. The results showed that five main anthocyanin compounds and the most abundant anthocyanin were the same in different tissues, while the second-highest anthocyanin between three tissues was different, even in the same cultivar. In conclusion, this study combined anthocyanin profiles and comparative transcriptomic analysis to identify candidate genes involved in anthocyanin biosynthesis in carrots, thus providing a better foundation for improving anthocyanin accumulation in carrots as a source of colorants.
黑胡萝卜的特点是含有大量花青素，花青素不仅是天然食用色素的良好来源，还能为人类带来诸多健康益处。在本研究中，利用不同胡萝卜基因型的主根来鉴定与花青素合成相关的候选基因，特别关注R2R3MYB、bHLH转录因子和谷胱甘肽S-转移酶基因（）。RNA测序分析（RNA-Seq）表明，和具有基因型依赖性表达，它们可能参与花青素生物合成的调控。它们在实心黑色主根中特异性上调，包括黑色韧皮部和木质部。与橙色样本相比，（LOC108204485）在所有黑色样本中均上调。我们还发现（LOC108205254）可能是一种重要的花青素转运蛋白，其上调表达导致黑色样本中液泡花青素积累增加。此外，采用高效液相色谱（HPLC）分析和液相色谱-质谱联用（LC-MS）来鉴定两个胡萝卜品种紫色组织中的单个花青素。结果表明，不同组织中五种主要花青素化合物和最丰富的花青素相同，而同一品种三个组织中第二丰富的花青素不同。总之，本研究结合花青素谱和比较转录组分析来鉴定胡萝卜中参与花青素生物合成的候选基因，从而为提高胡萝卜作为色素来源的花青素积累提供了更好的基础。
