Peach Carboxylesterase PpCXE1 Is Associated with Catabolism of Volatile Esters
Peach Carboxylesterase PpCXE1 Is Associated with Catabolism of Volatile Esters
复制标题
桃羧酸酯酶 PpCXE1 与挥发性酯的分解代谢相关
DOI：
10.1021/acs.jafc.9b01166
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发表时间：
2019-05-08
影响因子：
6.1
通讯作者：
Zhang, Bo
中科院分区：
文献类型：
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作者：
Cao, Xiangmei;Xie, Kaili;Zhang, Bo
桃子挥发性醋酸酯会影响消费者的感官偏好，并有助于防御生物胁迫。先前的研究表明，醇酰基转移酶 (AAT) 家族 PpAAT1 与桃果实中挥发性酯的形成相关。然而，水果还含有水解酯的羧酸酯酶（CXE）。该家族在挥发性酯含量方面的功能尚未被探索。在这里，我们观察到醋酸酯的含量与PpCXE1的表达呈负相关。重组 PpCXE1 蛋白对桃果实中的醋酸酯表现出水解活性。动力学分析表明，PpCXE1 对乙酸 E-2-己烯酯表现出最高的催化活性。亚细胞定位证明 PpCXE1 存在于细胞质中。桃果实中的瞬时表达和番茄果实中的稳定过表达导致体内挥发性酯的显着减少。综上所述，结果表明 PpCXE1 表达与桃果实中挥发性醋酸酯的分解代谢有关。
Peach fruit volatile acetate esters impact consumer sensory preference and contribute to defense against biotic stresses. Previous studies showed that alcohol acyltransferase (AAT) family PpAAT1 is correlated with volatile ester formation in peach fruits. However, fruits also contain carboxylesterase (CXE) enzymes that hydrolyze esters. The functions of this family with regard to volatile ester content has not been explored. Here, we observed that content of acetate ester was negatively correlated with expression of PpCXE1. Recombinant PpCXE1 protein exhibited hydrolytic activity toward acetate esters present in peach fruit. Kinetic analysis showed that PpCXE1 showed the highest catalytic activity toward E-2-hexenyl acetate. Subcellular localization demonstrated that PpCXE1 is present in the cytoplasm. Transient expression in peach fruit and stable overexpression in tomato fruit resulted in significant reduction of volatile esters in vivo. Taken together, the results indicate that PpCXE1 expression is associated with catabolism of volatile acetate esters in peach fruit.