Zhong Chunmei, Tang Yi, Pang Bin, Li Xukun, Yang Yuping, Deng Jing, Feng Chengyong, Li Lingfei, Ren Guiping, Wang Yaqin, Peng Jianzong, Sun Shulan, Liang Shan, Wang Xiaojing
1College of Forestry and Landscape Architecture; Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, P.R. China, South China Agricultural University, Guangzhou, 510642 China.
2Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631 China.
Hortic Res. 2020 May 20;7:78. doi: 10.1038/s41438-020-0296-2. eCollection 2020.
Anthocyanins and flavonols have vital roles in flower coloration, plant development, and defense. Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates, these pathways may compete for substrates. However, the mechanism regulating this potential competition remains unclear. Here, we identified GhMYB1a, an R2R3-MYB transcription factor involved in the regulation of anthocyanin and flavonol accumulation in (). GhMYB1a shares high sequence similarity with that of other characterized regulators of flavonol biosynthesis. In addition, GhMYB1a is also phylogenetically grouped with these proteins. The overexpression of in and tobacco () resulted in decreased anthocyanin accumulation and increased accumulation of flavonols by upregulating the structural genes involved in flavonol biosynthesis. We further found that GhMYB1a functions as a homodimer instead of interacting with basic helix-loop-helix cofactors. These results suggest that GhMYB1a is involved in regulating the anthocyanin and flavonol metabolic pathways through precise regulation of gene expression. The functional characterization of provides insight into the biosynthesis and regulation of flavonols and anthocyanins.
花青素和黄酮醇在花色形成、植物发育及防御过程中发挥着重要作用。由于花青素和黄酮醇具有相同的亚细胞定位和共同的生物合成底物，这些途径可能会竞争底物。然而，调节这种潜在竞争的机制仍不清楚。在此，我们鉴定出了GhMYB1a，一种参与调控（此处括号内容缺失相关信息）中花青素和黄酮醇积累的R2R3-MYB转录因子。GhMYB1a与其他已鉴定的黄酮醇生物合成调节因子具有高度的序列相似性。此外，GhMYB1a在系统发育上也与这些蛋白归为一类。在（此处括号内容缺失相关信息）和烟草（此处括号内容缺失相关信息）中过表达（此处内容缺失相关信息）导致花青素积累减少，通过上调参与黄酮醇生物合成的结构基因使黄酮醇积累增加。我们进一步发现，GhMYB1a以同源二聚体的形式发挥作用，而非与碱性螺旋-环-螺旋辅助因子相互作用。这些结果表明，GhMYB1a通过精确调控基因表达参与调节花青素和黄酮醇代谢途径。（此处内容缺失相关信息）的功能特性为黄酮醇和花青素的生物合成及调控提供了见解。
