Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, National Crop Gene Bank Building, Zhongguancun South Street No. 12, Haidian District, Beijing, 100081, China.
Department of Crop Science, College of Agriculture & Life Sciences, Chungnam National University, Yuseong-gu, Daejeon, 305-754, Republic of Korea.
Plant J. 2022 Jul;111(2):323-334. doi: 10.1111/tpj.15800. Epub 2022 May 18.
Buckwheat accumulates abundant flavonoids, which exhibit excellent health-promoting value. Flavonoids biosynthesis is mediated by a variety of phytohormones, among which jasmonates (JAs) induce numerous transcription factors, taking part in regulation of flavonoids biosynthesis genes. However, some transcriptional repressors appeared also induced by JAs. How these transcriptional repressors coordinately participate in JA signaling remains unclear. Here, we found that the disruption of the GCC-box in FtF3H promoter was associated with flavonoids accumulation in Tartary buckwheat. Further, our study illustrated that the nucleus-localized FtERF-EAR3 could inhibit FtF3H expression and flavonoids biosynthesis through binding the GCC-box in the promoter of FtF3H. The JA induced FtERF-EAR3 gene expression while facilitating FtERF-EAR3 protein degradation via the FtBPM3-dependent 26S proteasome pathway. Overall, these results illustrate a precise modulation mechanism of JA-responsive transcription suppressor participating in flavonoid biosynthesis, and will further help to improve the efficiency of flavonoids biosynthesis in Tartary buckwheat.
荞麦积累了丰富的类黄酮，具有极好的促进健康的价值。类黄酮的生物合成由多种植物激素介导，其中茉莉酸（JAs）诱导许多转录因子，参与类黄酮生物合成基因的调控。然而，一些转录抑制剂也被 JAs 诱导。这些转录抑制剂如何协同参与 JA 信号仍然不清楚。在这里，我们发现 FtF3H 启动子中 GCC 框的破坏与苦荞中类黄酮的积累有关。此外，我们的研究表明，定位于核内的 FtERF-EAR3 可以通过结合 FtF3H 启动子中的 GCC 框来抑制 FtF3H 的表达和类黄酮的生物合成。JA 诱导 FtERF-EAR3 基因表达，同时通过 FtBPM3 依赖的 26S 蛋白酶体途径促进 FtERF-EAR3 蛋白降解。总的来说，这些结果说明了 JA 反应性转录抑制剂参与类黄酮生物合成的精确调控机制，并将进一步有助于提高苦荞中类黄酮生物合成的效率。
