State Key Laboratory of Plant Diversity and Specialty Crops, CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of Chinese Academy of Sciences, Wuhan, 430074, China.
Apple technology innovation center of Shandong Province, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, Shandong, China.
New Phytol. 2024 Aug;243(3):997-1016. doi: 10.1111/nph.19888. Epub 2024 Jun 7.
Jasmonic acid (JA) and gibberellin (GA) coordinately regulate plant developmental programs and environmental cue responses. However, the fine regulatory network of the cross-interaction between JA and GA remains largely elusive. In this study, we demonstrate that MdNAC72 together with MdABI5 positively regulates anthocyanin biosynthesis through an exquisite MdNAC72-MdABI5-MdbHLH3 transcriptional cascade in apple. MdNAC72 interacts with MdABI5 to promote the transcriptional activation of MdABI5 on its target gene MdbHLH3 and directly activates the transcription of MdABI5. The MdNAC72-MdABI5 module regulates the integration of JA and GA signals in anthocyanin biosynthesis by combining with JA repressor MdJAZ2 and GA repressor MdRGL2a. MdJAZ2 disrupts the MdNAC72-MdABI5 interaction and attenuates the transcriptional activation of MdABI5 by MdNAC72. MdRGL2a sequesters MdJAZ2 from the MdJAZ2-MdNAC72 protein complex, leading to the release of MdNAC72. The E3 ubiquitin ligase MdSINA2 is responsive to JA and GA signals and promotes ubiquitination-dependent degradation of MdNAC72. The MdNAC72-MdABI5 interface fine-regulates the integration of JA and GA signals at the transcriptional and posttranslational levels by combining MdJAZ2, MdRGL2a, and MdSINA2. In summary, our findings elucidate the fine regulatory network connecting JA and GA signals with MdNAC72-MdABI5 as the core in apple.
茉莉酸(JA)和赤霉素(GA)协同调节植物发育程序和环境线索反应。然而,JA 和 GA 之间交叉相互作用的精细调控网络在很大程度上仍难以捉摸。在这项研究中,我们证明 MdNAC72 与 MdABI5 一起通过在苹果中一个精确的 MdNAC72-MdABI5-MdbHLH3 转录级联正向调控花青素生物合成。MdNAC72 与 MdABI5 相互作用,促进 MdABI5 对其靶基因 MdbHLH3 的转录激活,并直接激活 MdABI5 的转录。MdNAC72-MdABI5 模块通过与 JA 抑制剂 MdJAZ2 和 GA 抑制剂 MdRGL2a 结合,调节 JA 和 GA 信号在花青素生物合成中的整合。MdJAZ2 破坏 MdNAC72-MdABI5 相互作用,减弱 MdNAC72 对 MdABI5 的转录激活。MdRGL2a 将 MdJAZ2 从 MdJAZ2-MdNAC72 蛋白复合物中隔离出来,导致 MdNAC72 的释放。E3 泛素连接酶 MdSINA2 对 JA 和 GA 信号作出反应,并促进 MdNAC72 的泛素化依赖性降解。MdNAC72-MdABI5 界面通过结合 MdJAZ2、MdRGL2a 和 MdSINA2,在转录和翻译后水平上精细调节 JA 和 GA 信号的整合。总之,我们的研究结果阐明了连接 JA 和 GA 信号与 MdNAC72-MdABI5 的精细调控网络,该网络以苹果为核心。