College of Enology, Heyang Viti-viniculture Station, Northwest A & F University, Yangling, 712100, Shaanxi, China; Life School of Science and Technology, Henan Institute of Science and Technology, Xinxiang, 453003, Henan, China.
College of Enology, Heyang Viti-viniculture Station, Northwest A & F University, Yangling, 712100, Shaanxi, China.
Plant Physiol Biochem. 2020 Jun;151:621-629. doi: 10.1016/j.plaphy.2020.04.015. Epub 2020 Apr 18.
3-Isobutyl-2-methoxypyrazine (IBMP) is an important odor compound that revives unripe grapes or poor-quality wine. The biosynthesis of IBMP in grape berries is under the catalysis of Vitis vinifera O-methyltranferase 3 (VvOMT3). The homologous verification in this paper was carried out with the transient overexpression technique. The results showed that both the expression levels of the VvOMT3 gene and the IBMP concentration in 'Red globe' grapes increased significantly, which suggested that VvOMT3 could function in the biosynthesis of IBMP. Based on β-glucuronidase (GUS) staining results, blue color was only observed in grape pulp, not in grape skin, which indicated that VvOMT3 was expressed in grape pulp. The outcomes of the subcellular location examination performed on the protoplasts of Arabidopsis thaliana showed that the VvOMT3 protein was located on the inner surface of the cytoplasmic membrane. In summary, the VvOMT3 enzyme may function at the inner surface of the cytoplasmic membrane of pulp cells during grape development. These results will provide a background for future research on the catalytic mechanisms of VvOMT3.
3-异丁基-2-甲氧基吡嗪（IBMP）是一种重要的气味化合物，能使未成熟的葡萄或劣质葡萄酒恢复生机。葡萄浆果中 IBMP 的生物合成是在葡萄 Vitis vinifera O-甲基转移酶 3（VvOMT3）的催化下进行的。本文通过瞬时过表达技术进行了同源验证。结果表明，'红地球'葡萄中 VvOMT3 基因的表达水平和 IBMP 浓度均显著升高，表明 VvOMT3 可参与 IBMP 的生物合成。基于β-葡萄糖醛酸酶（GUS）染色结果，仅在葡萄果肉中观察到蓝色，而在葡萄皮中未观察到，这表明 VvOMT3 在葡萄果肉中表达。对拟南芥原生质体进行的亚细胞定位检测结果表明，VvOMT3 蛋白位于细胞质膜的内表面。综上所述，VvOMT3 酶可能在葡萄发育过程中在果肉细胞的细胞质膜内表面发挥作用。这些结果将为未来研究 VvOMT3 的催化机制提供背景。
