Plant pathogenic Gram-negative bacteria evade the host plant immune system by secreting Type III (T3E) and Type IV effector (T4E) proteins into the plant cytoplasm. Mostly T3Es are secreted into the plant cells to establish pathogenicity by affecting the vital plant process viz. metabolic pathways, signal transduction and hormonal regulation. Ubiquitin-26S proteasome system (UPS) exists as one of the important pathways in plants to control plant immunity and various cellular processes by employing several enzymes and enzyme components. Pathogenic and non-pathogenic bacteria are found to secrete effectors into plants with structural and/or functional similarity to UPS pathway components like ubiquitin E3 ligases, F-box domains, cysteine proteases, inhibitor of host UPS or its components, etc. The bacterial effectors mimic UPS components and target plant resistance proteins for degradation by proteasomes, thereby taking control over the host cellular activities as a strategy to exert virulence. Thus, the bacterial effectors circumvent plant cellular pathways leading to infection and disease development. This review highlights known bacterial T3E and T4E proteins that function and interfere with the ubiquitination pathway to regulate the immune system of plants.

植物致病性革兰氏阴性菌通过将 III 型 (T3E) 和 IV 型效应 (T4E) 蛋白分泌到植物细胞质中来逃避宿主植物免疫系统。大多数T3Es被分泌到植物细胞中，通过影响重要的植物过程即确定致病性。代谢途径、信号转导和激素调节。泛素-26S 蛋白酶体系统 (UPS) 作为植物中通过使用多种酶和酶组分来控制植物免疫和各种细胞过程的重要途径之一存在。发现致病和非致病细菌将效应物分泌到植物中，其结构和/或功能与 UPS 途径组分如泛素 E3 连接酶、F-box 结构域、半胱氨酸蛋白酶、宿主 UPS 抑制剂或其组分等具有相似性。细菌效应器模拟 UPS 成分并靶向植物抗性蛋白以被蛋白酶体降解，从而将控制宿主细胞活动作为发挥毒力的策略。因此，细菌效应器绕过导致感染和疾病发展的植物细胞途径。这篇综述重点介绍了已知的细菌 T3E 和 T4E 蛋白，它们发挥作用并干扰泛素化途径以调节植物的免疫系统。