地黄是一种药用植物,木本植物科,并以其粉红色或紫色的大花冠而闻名。然而,到目前为止,尚未对花色形成的分子机制进行研究。在这项研究中,我们研究了根的转录组,茎,利用转录组测序技术,组装了144582个单基因。共有58个花青素生物合成基因被鉴定在花青素转录组中。其中14个与花青素含量高度相关,尤其是RpF3H2、RpDFR2、RpANS1、RpANS2和RpUFGT。完全正确,35个FPKM值大于5的MYB基因被鉴定在比西氏菌转录组中,包括R2R3MYB转录因子RpMYB1,其属于R2R3MYB家族的6亚群。农杆菌介导的烟草瞬时表达表明,过表达RpMYB1可以激活花色苷合成途径中结构基因的表达,促进花色苷在N.benthamiana叶片中的积累。表明RpMYB1是花色苷合成的正调节因子。此外,RpMYB1与RpANS1的瞬时过表达,RpMYB1RpANS1与其他结构基因的组合都可以进一步增强N.benthamiana叶片中花色苷的积累。RpMYB1在谷蛋白中的永久过表达促进了花色苷的积累和RgCHS的表达水平,RgF3H,RgDFR和RgANS。来自双荧光素酶测定的进一步证据表明RpMYB1可以结合RpDFR2的启动子并因此激活其表达。这些发现为花色R的花色苷生物合成的分子调控提供了见解,并为花色的遗传改良提供了宝贵的遗传资源。
Rehmannia piasezkii is a kind of medicinal plants, of the Orobanchaceae family, and well known for its large pink or purple corolla. However, no research on the molecular mechanism of flower color formation in R. piasezkii has been conducted so far. In this study, we investigated the transcriptome of root, stem, leaf and corollas of R. piasezkii using transcriptome sequencing technology and assembled 144,582 unigenes. A total of 58
anthocyanin biosynthetic genes were identified in the R. piasezkii transcriptome, fourteen of which were highly correlated with
anthocyanin content, especially RpF3H2, RpDFR2, RpANS1, RpANS2 and RpUFGT. Totally, 35 MYB genes with FPKM values greater than 5 were identified in the R. piasezkii transcriptome, including an R2R3 MYB transcriptional factor RpMYB1, which belongs to subgroup 6 of the R2R3 MYB family. Agrobacterium-mediated transient expression of Nicotiana benthamiana revealed that overexpression of RpMYB1 could activate the expression of structural genes in
anthocyanin synthesis pathway and promote the accumulation of anthocyanins in N. benthamiana leaves, indicating that RpMYB1 is a positive regulator of anthocyanin synthesis. Furthermore, combined transient overexpression of RpMYB1 with RpANS1, RpMYB1+RpANS1 with other structural genes all could further enhance the accumulation of anthocyanins in N. benthamiana leaves. Permanent overexpression of RpMYB1 in R. glutinosa promoted
anthocyanin accumulation and expression levels of RgCHS, RgF3H, RgDFR and RgANS. Further evidence from dual-luciferase assay suggested that RpMYB1 could bind to the promoter of RpDFR2 and hence activating its expression. These findings provide insight into the molecular regulation in
anthocyanin biosynthesis in R. piasezkii and provide valuable genetic resources for the genetic improvement of flower color.