College of Horticulture, Shandong Agricultural University, Taian, 271000, Shandong, China.
College of Horticulture, Shandong Agricultural University, Taian, 271000, Shandong, China.
Plant Sci. 2021 May;306:110848. doi: 10.1016/j.plantsci.2021.110848. Epub 2021 Feb 13.
Red-fleshed apple fruits are popular because of their high flavonoid content. Although MdMYB10 and its homologs have been identified as crucial regulators of the fruit coloring process, other transcription factors (TFs) contributing to the differences in flesh coloration have not been fully characterized. In this study, we investigated the regulatory effects of MdWRKY41 on anthocyanin and proanthocyanidin (PA) synthesis in red-fleshed apples. The overexpression of MdWRKY41 in red-fleshed apple calli inhibited anthocyanin and PA accumulation by downregulating the expression of a MYB TF gene (MdMYB12) and specific structural genes (MdLAR, MdUFGT, and MdANR). Furthermore, MdWRKY41 was shown to interact with MdMYB16 to form a complex that can further suppress MdANR and MdUFGT expression. Interestingly, MdWRKY41 was targeted by the photoresponse factor MdHY5 and inhibited its transcription. Overall, our findings provide insights into a novel MdHY5-MdWRKY41-MdMYB regulatory module influencing anthocyanin and PA synthesis in red-fleshed apple fruits.
红肉苹果因其高类黄酮含量而广受欢迎。虽然 MdMYB10 及其同源物已被鉴定为果实着色过程的关键调控因子，但其他参与果肉颜色差异的转录因子（TFs）尚未得到充分表征。在本研究中，我们研究了 MdWRKY41 对红肉苹果中花色苷和原花色素（PA）合成的调控作用。在红肉苹果愈伤组织中过表达 MdWRKY41 通过下调 MYB TF 基因（MdMYB12）和特定结构基因（MdLAR、MdUFGT 和 MdANR）的表达，抑制了花色苷和 PA 的积累。此外，MdWRKY41 被证明与 MdMYB16 相互作用形成一个复合物，可进一步抑制 MdANR 和 MdUFGT 的表达。有趣的是，MdWRKY41 是光响应因子 MdHY5 的靶标，并抑制其转录。总的来说，我们的研究结果提供了一个新的 MdHY5-MdWRKY41-MdMYB 调控模块的见解，该模块影响红肉苹果果实中花色苷和 PA 的合成。
