Huang Yun, Gao Jiahui, Ji Guiming, Li Wenjing, Wang Jiaxue, Wang Qinghua, Shen Yuanyue, Guo Jiaxuan, Gao Fan
Beijing Key Laboratory for Agricultural Application and New Technique, College of Plant Science and Technology, Beijing University of Agriculture, Beijing 102206, China.
Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, College of Bioscience and Resources Environment, Beijing University of Agriculture, Beijing 102206, China.
Plant Cell. 2025 Feb 13;37(2). doi: 10.1093/plcell/koaf022.
Polyamines (PAs), such as putrescine, spermidine, and spermine, are essential for plant growth and development. However, the post-translational regulation of PA metabolism remains unknown. Here, we report the COP9 SIGNALOSOME SUBUNIT 5A (FvCSN5A) mediates the degradation of the POLYAMINE OXIDASE 5 (FvPAO5), which catalyzes the conversion of spermidine/spermine to produce H2O2 in strawberry (Fragaria vesca). FvCSN5A is localized in the cytoplasm and nucleus, is ubiquitously expressed in strawberry plants, and is rapidly induced during fruit ripening. FvCSN5A RNA interference (RNAi) transgenic strawberry lines exhibit pleiotropic effects on plant development, fertility, and fruit ripening due to altered PA and H2O2 homeostasis, similar to FvPAO5 transgenic overexpression lines. Moreover, FvCSN5A interacts with FvPAO5 in vitro and in vivo, and the ubiquitination and degradation of FvPAO5 are impaired in FvCSN5A RNAi lines. Additionally, FvCSN5A interacts with cullin 1 (FvCUL1), a core component of the E3 ubiquitin-protein ligase complex. Transient genetic analysis in cultivated strawberry (Fragaria × ananassa) fruits showed that inhibiting FaPAO5 expression could partially rescue the ripening phenotype of FaCSN5A RNAi fruits. Taken together, our results suggest that the CSN5A-CUL1-PAO5 signaling pathway responsible for PA and H2O2 homeostasis is crucial for strawberry vegetative and reproductive growth in particular fruit ripening. Our findings present a promising strategy for improving crop yield and quality.
多胺（PAs），如腐胺、亚精胺和精胺，对植物的生长发育至关重要。然而，多胺代谢的翻译后调控仍不清楚。在此，我们报道了COP9信号体亚基5A（FvCSN5A）介导多胺氧化酶5（FvPAO5）的降解，FvPAO5催化草莓（野草莓）中亚精胺/精胺转化生成过氧化氢。FvCSN5A定位于细胞质和细胞核，在草莓植株中普遍表达，并在果实成熟过程中迅速被诱导。FvCSN5A RNA干扰（RNAi）转基因草莓株系由于多胺和过氧化氢稳态的改变，对植物发育、育性和果实成熟表现出多效性，类似于FvPAO5转基因过表达株系。此外，FvCSN5A在体外和体内均与FvPAO5相互作用，并且FvPAO5的泛素化和降解在FvCSN5A RNAi株系中受损。此外，FvCSN5A与E3泛素蛋白连接酶复合体的核心成分cullin 1（FvCUL1）相互作用。对栽培草莓（凤梨草莓）果实进行的瞬时遗传分析表明，抑制FaPAO5的表达可部分挽救FaCSN5A RNAi果实的成熟表型。综上所述，我们的结果表明，负责多胺和过氧化氢稳态的CSN5A-CUL1-PAO5信号通路对草莓的营养生长和生殖生长尤其是果实成熟至关重要。我们的发现为提高作物产量和品质提供了一个有前景的策略。
