DUS Test (Kunming) Station of Ministry of Agriculture, Quality Standard and Testing Technology Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, People's Republic of China.
Development Center of Science and Technology, Ministry of Agriculture, Beijing, 100122, People's Republic of China.
Environ Sci Pollut Res Int. 2019 May;26(14):13785-13794. doi: 10.1007/s11356-018-2779-3. Epub 2018 Aug 25.
Anthocyanin biosynthesis is one of the best studied secondary metabolisms. However, related pathways were generally concluded based on anthocyanin components; most studies focused on the backbone forming of anthocyanidins (cyanidin, delphinidin, and pelargonidin) of model or commercial plants, while anthocyanin modification was less discussed, and non-model plants with abundant colorations were less researched either. Ranunculus asiaticus L. has great diversity in flower colorations, not only indicating its value in researching anthocyanin biosynthesis but also implying it is unique in this regard. Based on transcriptome sequencing and gene annotation of three varieties (10 samples) of Ranunculus asiaticus L., 176 unigenes from 151,136 unigenes were identified as involved in anthocyanin biosynthesis, among which, 74 unigenes were related to anthocyanin modification; 61 unigenes were responsible for glycosylation at C3 and C5 with 3-monosaccharides of glucose, 3-biosides of rutinose, sophorose, or sambubiose to form 3Gly-, 3Gly5Gly-, 3Gly3'Gly-, 3Gly2''Gly-, 3Gly2''Xly-, 3Gly2''Rly-glycosylated anthocyanins, etc.; 2 unigenes transferred -CH; 11 unigenes of BAHD family catalyzd the aromatic or malonyl acylation at 6'' / 6''''position of 3/5-O-glucoside. Based on gene composition, a putative pathway was established. The pathway was validated by flower colorations, and gene expression patterns where F3H, F3'H, 3GT, 5GT, and FMT2 were highly expressed in varieties colored as lateritious and carmine, while variety with purple flowers had high expression of F3'5'H and 3MAT. In view of anthocyanin biosynthesis pathway of Ranunculus asiaticus L., great diversity in its flower colorations was illustrated via the complete branches (F3H, F3'H and F3'5'H) as well as complete modifications (glycosylation, methylation, and acylation), and besides, via the higher percentage of C3 glycosylation than C5 glycosylation.
花色苷生物合成是研究最多的次生代谢途径之一。然而，相关途径通常是根据花色苷成分得出的；大多数研究集中在模式或商业植物中花色苷（矢车菊素、飞燕草素和天竺葵素）的骨干形成上，而花色苷的修饰则讨论较少，具有丰富色彩的非模式植物也研究较少。毛茛花色丰富多彩，不仅表明其在研究花色苷生物合成方面具有价值，而且表明其在这方面具有独特性。基于三种毛茛花色（10 个样本）的转录组测序和基因注释，从 151136 个 unigenes 中鉴定出 176 个 unigenes参与花色苷生物合成，其中 74 个 unigenes与花色苷修饰有关；61 个 unigenes负责在 C3 和 C5 位与葡萄糖的 3-单糖、芦丁糖、槐糖或山梨糖的 3-糖苷、3Gly-、3Gly5Gly-、3Gly3'Gly-、3Gly2''Gly-、3Gly2''Xly-、3Gly2''Rly-等糖苷化花色苷；2 个 unigenes转移-CH；11 个 BAHD 家族的 unigenes催化 3/5-O-糖苷的 6'/6''''位的芳香或丙二酰化。基于基因组成，建立了一个假设的途径。该途径通过花色苷和基因表达模式得到验证，在花色为橙红色和胭脂红色的品种中，F3H、F3'H、3GT、5GT 和 FMT2 的表达水平较高，而紫色花品种中 F3'5'H 和 3MAT 的表达水平较高。鉴于毛茛花色苷生物合成途径，花色苷完全分支（F3H、F3'H 和 F3'5'H）以及完全修饰（糖基化、甲基化和酰化）以及 C3 糖基化的比例高于 C5 糖基化，说明了其花色的多样性。
