Yang Jianfei, Chen Yunzhu, Xiao Zhihong, Shen Hailong, Li Yuhua, Wang Yu
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China.
School of Forestry, Northeast Forestry University, Harbin, China.
Front Plant Sci. 2022 Sep 6;13:1008829. doi: 10.3389/fpls.2022.1008829. eCollection 2022.
Anthocyanins are common secondary metabolites in plants that confer red, blue, and purple colorations in plants and are highly desired by consumers for their visual appearance and nutritional quality. In the last two decades, the anthocyanin biosynthetic pathway and transcriptional regulation of anthocyanin biosynthetic genes (ABGs) have been well characterized in many plants. From numerous studies on model plants and horticultural crops, many signaling regulators have been found to control anthocyanin accumulation regulation of anthocyanin-promoting R2R3-MYB transcription factors (so-called R2R3-MYB activators). The regulatory mechanism of R2R3-MYB activators is mediated by multiple environmental factors (e.g., light, temperature) and internal signals (e.g., sugar, ethylene, and JA) in complicated interactions at multiple levels. Here, we summarize the transcriptional control of R2R3-MYB activators as a result of natural variations in the promoter of their encoding genes, upstream transcription factors and epigenetics, and posttranslational modifications of R2R3-MYB that determine color variations of horticultural plants. In addition, we focus on progress in elucidating the integrated regulatory network of anthocyanin biosynthesis mediated by R2R3-MYB activators in response to multiple signals. We also highlight a few gene cascade modules involved in the regulation of anthocyanin-related R2R3-MYB to provide insights into anthocyanin production in horticultural plants.
花青素是植物中常见的次生代谢产物，赋予植物红色、蓝色和紫色，因其视觉外观和营养品质而备受消费者青睐。在过去二十年中，许多植物中花青素生物合成途径以及花青素生物合成基因（ABGs）的转录调控已得到充分表征。通过对模式植物和园艺作物的大量研究，发现许多信号调节因子可控制花青素积累，即调节促进花青素合成的R2R3-MYB转录因子（所谓的R2R3-MYB激活因子）。R2R3-MYB激活因子的调控机制由多种环境因素（如光照、温度）和内部信号（如糖、乙烯和茉莉酸）在多个层面的复杂相互作用介导。在此，我们总结了R2R3-MYB激活因子的转录调控，这是其编码基因启动子的自然变异、上游转录因子和表观遗传学以及R2R3-MYB的翻译后修饰所导致的结果，这些因素决定了园艺植物的颜色变化。此外，我们关注在阐明由R2R3-MYB激活因子介导的响应多种信号的花青素生物合成综合调控网络方面取得的进展。我们还强调了一些参与花青素相关R2R3-MYB调控的基因级联模块，以深入了解园艺植物中的花青素生成。
