Abstract: Ubiquitin/26S proteasome system (UPS) is an essential pathway of protein ubiquitination. As a post-translational modification process, UPS plays an important role in all crop growth and development stages. Many studies have shown that ubiquitin receptor protein,  E3 ubiquitin ligase, and deubiquitinase in UPS could coordinate with each other. By connecting or removing different amounts of ubiquitin on the target protein, they could mediate the degradation of the target protein, change the subcellular localization and protein activity and regulate the seed size. This paper reviewed the research progress of ubiquitin/26S proteasome system regulating seed size in different crops. Its future development was prospected to provide a reference for the study of seed size regulation mechanism and breeding improvement.

Key words: ubiquitin /26S proteasome system, ubiquitination, E3 ubiquitin ligase, grain size

摘要： 泛素/26S蛋白酶体系统（ubiquitin/26S proteasome system, UPS）是蛋白质泛素化的重要途径，作为蛋白质翻译后重要的修饰系统，在作物生长发育的各个阶段发挥重要作用。大量研究表明，UPS中泛素受体蛋白、E3泛素连接酶、去泛素化酶等能相互协调，通过在目标蛋白上连接或去除不同数量的泛素来介导目标蛋白的降解、改变亚细胞定位、蛋白活性等，从而调控种子的大小。对不同作物中泛素/26S蛋白酶体系统调节种子大小方面的研究进展进行了综述，并对其未来的发展进行了展望，为研究种子大小的调控机制及育种改良提供参考。

关键词: 泛素/26S蛋白酶体系统, 泛素化, E3泛素连接酶, 种子大小