Vacuolar sorting is critically important in plants as it regulates the mobilization of proteins and plays a major role in important agricultural traits like yield and seed protein content. Vacuolar sorting receptors (VSRs) are integral membrane proteins that mediate protein trafficking from the Golgi apparatus to the vacuole via the intermediate membrane-bound prevacuolar compartment (PVC)/multivesicular body (MVB). VSR proteins, such as an 80 kD (BP-80) from pea, also serve as markers for PVC/MVB. Dissecting VSR-mediated protein trafficking pathways may provide ways to enhance agronomic traits and crop yield. Green fluorescence protein (GFP) fusions with the seven Arabidopsis (Arabidopsis thaliana) VSRs were previously shown to localize to PVCs in transgenic tobacco BY-2 cells. The Rice (Oryza sativa) genome contains seven VSRs (OsVSR1-7), but little is known about their subcellular localizations. Here we studied the subcellular localization of OsVSR1-7 b y using a reporter approach, in which GFP-OsVSR1-7 fusions containing the transmembrane domain (TMD) and cytoplasmic tail (CT) of individual OsVSR were expressed in the protoplasts of rice, transgenic tobacco BY-2 cells and transgenic rice plants. Immunofluorescent labelling studies and confocal laser scanning microscope observation demonstrated that the seven OsVSRs are localized to PVCs and form ring-like structures upon wortmannin treatment. Therefore, we have verified the subcellular localization of OsVSR1-7 in this study. The OsVSRs tagged with GFP can serve as PVCs/MVBs markers in rice for the future studies.

液泡分选在植物中至关重要，因为它调节蛋白质的动员，并在产量和种子蛋白质含量等重要农业性状中发挥重要作用。液泡分选受体 (VSR) 是整合膜蛋白，介导蛋白质通过中间膜结合液泡前区室 (PVC)/多泡体 (MVB) 从高尔基体运输到液泡。 VSR 蛋白，例如来自豌豆的 80 kD (BP-80)，也可用作 PVC/MVB 的标记物。剖析 VSR 介导的蛋白质运输途径可能提供增强农艺性状和作物产量的方法。绿色荧光蛋白 (GFP) 与七个拟南芥(Arabidopsis thaliana) VSR 的融合先前已被证明定位于转基因烟草 BY-2 细胞中的 PVC。水稻 ( Oryza sativa)基因组包含 7 个 VSR (OsVSR1-7)，但对其亚细胞定位知之甚少。在这里，我们使用报告基因方法研究了 OsVSR1-7 的亚细胞定位，其中包含个体 OsVSR 的跨膜结构域（TMD）和细胞质尾（CT）的 GFP-OsVSR1-7 融合体在水稻、转基因烟草的原生质体中表达BY-2 细胞和转基因水稻植物。免疫荧光标记研究和共焦激光扫描显微镜观察表明，七个 OsVSR 定位于 PVC，并在渥曼青处理后形成环状结构。因此，我们在本研究中验证了OsVSR1-7的亚细胞定位。带有 GFP 标记的 OsVSR 可以作为水稻中的 PVC/MVB 标记，用于未来的研究。