Lotus is an important aquatic ornamental plant, whose flower color is one of the key horticultural traits that determines its ornamental value. Previous studies revealed that anthocyanins largely determined the red color of lotus flower, which is also the main component that has beneficial effects on human health. However, the regulation mechanism of flower pigmentation in lotus flower remains unclear. In the present study, in order to further understand the regulatory mechanism underlying the anthocyanin biosynthesis, a bHLH gene was characterized to be phylogenetically close to AtTT8 and the bHLH proteins from other plant species that have been indicated to be involved in the positive regulation of anthocyanin biosynthesis. Complementation analysis in Arabidopsis tt8 mutant showed that NnTT8 could function similarly to AtTT8 in regulating anthocyanin and proanthocyanin biosynthesis. An MYB transcription factor capable of interacting with NnTT8 was also characterized from lotus. The identification of a bHLH transcription factor playing regulatory roles in anthocyanin biosynthesis is crucial, as it might help to obtain more in-depth insight into the coloration of lotus and help in breeding high anthocyanin content lotus variety that can be explored for lotus flower beverages.

莲花是一种重要的水生观赏植物，其花色是决定其观赏价值的关键园艺特征之一。先前的研究表明，花色苷在很大程度上决定了莲花的红色，这也是对人体健康有益的主要成分。然而，莲花中花色素沉着的调节机制仍不清楚。在本研究中，为了进一步了解花色苷生物合成的调控机制，将bHLH基因的系统发育特征与AtTT8接近，并且已表明来自其他植物物种的bHLH蛋白也参与了花色苷的正向调控。生物合成。拟南芥tt8中的互补分析该突变体表明，NnTT8在调节花色苷和原花青素的生物合成方面与AtTT8具有相似的功能。还从莲花中鉴定了能够与NnTT8相互作用的MYB转录因子。鉴定在花色苷生物合成中起调节作用的bHLH转录因子至关重要，因为它可能有助于获得对莲花色泽的更深入了解，并有助于培育可用于莲花饮料的高花色苷含量的莲花品种。