Qian Minjie, Wu Hongxia, Yang Chengkun, Zhu Wencan, Shi Bin, Zheng Bin, Wang Songbiao, Zhou Kaibing, Gao Aiping
Sanya Nanfan Research Institute of Hainan University, Sanya, China.
Ministry of Agriculture Key Laboratory of Tropical Fruit Biology, South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, China.
Front Plant Sci. 2023 Jan 18;13:1119384. doi: 10.3389/fpls.2022.1119384. eCollection 2022.
Flavonoids are important water soluble secondary metabolites in plants, and light is one of the most essential environmental factors regulating flavonoids biosynthesis. In the previous study, we found bagging treatment significantly inhibited the accumulation of flavonols and anthocyanins but promoted the proanthocyanidins accumulation in the fruit peel of mango ( L.) cultivar 'Sensation', while the relevant molecular mechanism is still unknown.
In this study, RNA-seq was conducted to identify the key pathways and genes involved in the light-regulated flavonoids biosynthesis in mango peel.
By weighted gene co-expression network analysis (WGCNA), 16 flavonoids biosynthetic genes were crucial for different flavonoids compositions biosynthesis under bagging treatment in mango. The higher expression level of () in bagged samples might be the reason why light inhibits proanthocyanidins accumulation in mango peel. The reported positively regulating anthocyanins biosynthesis in mango, , has also been identified by WGCNA in this study. Apart from MYB and bHLH, ERF, WRKY and bZIP were the three most important transcription factors (TFs) involved in the light-regulated flavonoids biosynthesis in mango, with both activators and repressors. Surprisingly, two transcripts, which are usually induced by light, showed higher expression level in bagged samples.
Our results provide new insights of the regulatory effect of light on the flavonoids biosynthesis in mango fruit peel.
类黄酮是植物中重要的水溶性次生代谢产物，而光是调节类黄酮生物合成的最重要环境因素之一。在先前的研究中，我们发现套袋处理显著抑制了芒果（品种‘Sensation’）果皮中黄酮醇和花青素的积累，但促进了原花青素的积累，而相关的分子机制仍然未知。
在本研究中，进行了RNA测序以鉴定参与芒果果皮中光调节类黄酮生物合成的关键途径和基因。
通过加权基因共表达网络分析（WGCNA），16种类黄酮生物合成基因对于套袋处理下芒果中不同类黄酮成分的生物合成至关重要。套袋样品中（）的较高表达水平可能是光抑制芒果果皮中原花青素积累的原因。本研究中通过WGCNA还鉴定出了在芒果中正向调节花青素生物合成的已报道的（）。除了MYB和bHLH外，ERF、WRKY和bZIP是参与芒果中光调节类黄酮生物合成的三个最重要的转录因子（TFs），既有激活因子也有抑制因子。令人惊讶的是，通常由光诱导的两个（）转录本在套袋样品中显示出较高的表达水平。
我们的结果为光对芒果果皮中类黄酮生物合成的调节作用提供了新的见解。
