Song Zunyang, Li Wenhui, Chen Hangcong, Shi Jingying, Zhu Hong, Chen Weixin, Lu Wangjin, Li Xueping, Zhu Xiaoyang
Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center for Postharvest Technology of Horticultural Crops in South China, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China.
Key Laboratory of Food Processing Technology and Quality Control in Shandong Province, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China.
New Phytol. 2025 Nov;248(3):1284-1303. doi: 10.1111/nph.70493. Epub 2025 Aug 22.
Ethylene regulates fruit ripening at transcriptional, posttranscriptional, translational and posttranslational levels. However, the multiple regulatory mechanisms remain unclear. Here, we revealed a module that regulates fruit ripening transcriptionally and posttranslationally. Ethylene and abscisic acid markedly induced both transcript and protein levels of MaERF113 and MaABI5-like, and MaERF113 activated the expression of genes related to starch (MaGWD1, MaBAM3 and MaAMY3) and Chl (MaSGR1 and MaPPH) degradation. Their function and regulatory network in fruit softening were investigated using physiological, molecular biology and genetic approaches. Ectopic and transient overexpression of MaERF113 promoted fruit ripening and induced starch and Chl degradation in both banana and tomato, while silencing of MaERF113 caused an opposite effect. MaERF113 interacted with an E3 ubiquitin ligase MaSINAT5, which ubiquitinated MaERF113 at the K78 site, mediated its degradation and attenuated MaERF113-mediated transactivation of target genes. MaSINAT5 overexpression delayed fruit ripening, whereas MaSINAT5-silencing accelerated it. Interestingly, MaABI5-like activated and interacted with MaERF113 to enhance the promoter activity of genes involved in starch and Chl degradation. Overall, our findings uncovered a dynamic regulatory module of MaSINAT5/MaABI5-like-MaERF113 mediating 'Fenjiao' banana ripening by regulating starch and Chl degradation, which advanced our understanding of site-specific ubiquitination modification and phytohormone crosstalk in regulating fruit ripening.
乙烯在转录、转录后、翻译和翻译后水平上调节果实成熟。然而，多种调控机制仍不清楚。在此，我们揭示了一个在转录和翻译后水平上调节果实成熟的模块。乙烯和脱落酸显著诱导了MaERF113和MaABI5-like的转录水平和蛋白水平，并且MaERF113激活了与淀粉（MaGWD1、MaBAM3和MaAMY3）和叶绿素（MaSGR1和MaPPH）降解相关基因的表达。利用生理学、分子生物学和遗传学方法研究了它们在果实软化中的功能和调控网络。MaERF113的异位和瞬时过表达促进了香蕉和番茄的果实成熟，并诱导了淀粉和叶绿素的降解，而MaERF113的沉默则产生相反的效果。MaERF113与E3泛素连接酶MaSINAT5相互作用，MaSINAT5在K78位点使MaERF113泛素化，介导其降解并减弱MaERF113介导的靶基因反式激活。MaSINAT5的过表达延迟了果实成熟，而MaSINAT5的沉默则加速了果实成熟。有趣的是，MaABI5-like激活并与MaERF113相互作用，以增强参与淀粉和叶绿素降解的基因的启动子活性。总体而言，我们的研究结果揭示了一个由MaSINAT5/MaABI5-like-MaERF113组成的动态调控模块，该模块通过调节淀粉和叶绿素降解来介导‘粉蕉’的果实成熟，这加深了我们对位点特异性泛素化修饰和植物激素信号转导在调控果实成熟中的相互作用的理解。
