Department of Resources Science of Traditional Chinese Medicines and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China.
Department of Biological and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, China.
Plant J. 2024 Oct;120(1):354-369. doi: 10.1111/tpj.16991. Epub 2024 Aug 19.
C-glycosides are a predominant class of flavonoids that demonstrate diverse medical properties and plant physiological functions. The chemical stability, structural diversity, and differential aboveground distribution of these compounds in plants make them ideal protectants. However, little is known about the transcriptional regulatory mechanisms that play these diverse roles in plant physiology. In this study, chard was selected from 69 families for its significantly different flavonoid C-glycosides distributions between the aboveground and underground parts to investigate the role and regulatory mechanism of flavonoid C-glycosides in plants. Our results indicate that flavonoid C-glycosides are affected by various stressors, especially UV-B. Through cloning and validation of key biosynthetic genes of flavonoid C-glycosides in chard (BvCGT1), we observed significant effects induced by UV-B radiation. This finding was further confirmed by resistance testing in BvCGT1 silenced chard lines and in Arabidopsis plants with BvCGT1 overexpression. Yeast one-hybrid and dual-luciferase assays were employed to determine the underlying regulatory mechanisms of BvCGT1 in withstanding UV-B stress. These results indicate a potential regulatory role of BvDof8 and BvDof13 in modulating flavonoid C-glycosides content, through their influence on BvCGT1. In conclusion, we have effectively demonstrated the regulation of BvCGT1 by BvDof8 and BvDof13, highlighting their crucial role in plant adaptation to UV-B radiation. Additionally, we have outlined a comprehensive transcriptional regulatory network involving BvDof8 and BvDof13 in response to UV-B radiation.
C-糖苷是黄酮类化合物中的主要类别，具有多种医学特性和植物生理功能。这些化合物在植物中的化学稳定性、结构多样性和地上部分的差异分布使它们成为理想的保护剂。然而，对于它们在植物生理学中发挥这些多样化作用的转录调控机制知之甚少。在这项研究中，我们选择了菠菜作为研究对象，因为其地上部分和地下部分的类黄酮 C-糖苷分布存在显著差异，旨在研究类黄酮 C-糖苷在植物中的作用和调控机制。
我们的研究结果表明，类黄酮 C-糖苷受多种胁迫因素的影响，尤其是 UV-B。通过克隆和验证菠菜（BvCGT1）中类黄酮 C-糖苷生物合成关键基因，我们观察到 UV-B 辐射诱导的显著影响。这一发现通过 BvCGT1 沉默的菠菜株系和 BvCGT1 过表达的拟南芥植物的抗性测试得到了进一步证实。酵母单杂交和双荧光素酶报告基因 assays 被用来确定 BvCGT1 在耐受 UV-B 胁迫中的潜在调控机制。这些结果表明，BvDof8 和 BvDof13 通过影响 BvCGT1，可能在调节类黄酮 C-糖苷含量方面发挥调节作用。
综上所述，我们有效地证明了 BvCGT1 受 BvDof8 和 BvDof13 的调控，突出了它们在植物适应 UV-B 辐射中的关键作用。此外，我们还概述了一个涉及 BvDof8 和 BvDof13 对 UV-B 辐射响应的综合转录调控网络。
