Liu Xue, Feng Qiuying, Yang Linlin, Xu Qijiang
Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin 150040, Heilongjiang, China.
Sheng Wu Gong Cheng Xue Bao. 2020 Aug 25;36(8):1620-1628. doi: 10.13345/j.cjb.190561.
Little is known about the molecular mechanism of currant anthocyanin synthesis. We investigated the effect of dfr, a key gene for anthocyanin synthesis in currant, on anthocyanins of different color currant. Black currant (Ribes nigrum L.), red currant (Ribes rubrum L.) and white currant (Ribes albrum L.) were used as test materials to determine the anthocyanin content at different stages of fruit development. Three full-length cDNA sequences of dfr gene were cloned by RACE (Rapid amplification of cDNA ends), and named as Rndfr, Rrdfr and Radfr. Phylogenetic analysis shows that Rndfr, Rrdfr and Radfr had high homology in evolution. The determination of anthocyanin content in different stages of fruit development shows that the content of anthocyanin in black currant and red currant was higher and gradually increased with the ripening of the fruit. While the content of anthocyanin in white currant was extremely low, and almost no anthocyanin was detected. Quantitative RT-PCR analysis shows that the expression level of dfr in black currant was higher than red currant and white currant in each period of fruit development. As the diameter of the fruit increased and the color of the peel deepened, the expression level of dfr in the black currant showed an increasing trend. In the red currant, the expression level gradually increased until the period of 75% fruit color, then the Rrdfr decreased rapidly. In white currant, the overall trend showed a downward trend, and its expression level was the lowest. All the results suggest that dfr gene plays a role in the process of fruit color.
关于醋栗花青素合成的分子机制，人们了解甚少。我们研究了醋栗花青素合成关键基因dfr对不同颜色醋栗花青素的影响。以黑醋栗（Ribes nigrum L.）、红醋栗（Ribes rubrum L.）和白醋栗（Ribes albrum L.）为试验材料，测定果实发育不同阶段的花青素含量。通过RACE（cDNA末端快速扩增）克隆了dfr基因的三个全长cDNA序列，分别命名为Rndfr、Rrdfr和Radfr。系统发育分析表明，Rndfr、Rrdfr和Radfr在进化上具有高度同源性。果实发育不同阶段花青素含量的测定结果表明，黑醋栗和红醋栗中的花青素含量较高，且随着果实成熟逐渐增加。而白醋栗中的花青素含量极低，几乎检测不到花青素。定量RT-PCR分析表明，在果实发育的各个时期，黑醋栗中dfr的表达水平均高于红醋栗和白醋栗。随着果实直径增大和果皮颜色加深，黑醋栗中dfr的表达水平呈上升趋势。在红醋栗中，表达水平逐渐升高，直至果实颜色达到75%时，Rrdfr迅速下降。在白醋栗中，总体呈下降趋势，其表达水平最低。所有结果表明，dfr基因在果实颜色形成过程中发挥作用。
