Plants produce and emit terpenes, including sesquiterpenes, during growth and development, which serve different functions in plants. The sesquiterpene nerolidol has health-promoting properties and adds a floral scent to plants. However, the glycosylation mechanism of nerolidol and its biological roles in plants remained unknown. Sesquiterpene UDP-glucosyltransferases were selected by using metabolites-genes correlation analysis, and its roles in response to cold stress were studied. We discovered the first plant UGT (UGT91Q2) in tea plant, whose expression is strongly induced by cold stress and which specifically catalyzes the glucosylation of nerolidol. The accumulation of nerolidol glucoside was consistent with the expression level of UGT91Q2 in response to cold stress, as well as in different tea cultivars. The reactive oxygen species (ROS) scavenging capacity of nerolidol glucoside was significantly higher than that of free nerolidol. Down-regulation of UGT91Q2 resulted in reduced accumulation of nerolidol glucoside, ROS scavenging capacity and tea plant cold tolerance. Tea plants absorbed airborne nerolidol and converted it to its glucoside, subsequently enhancing tea plant cold stress tolerance. Nerolidol plays a role in response to cold stress as well as in triggering plant-plant communication in response to cold stress. Our findings reveal previously unidentified roles of volatiles in response to abiotic stress in plants.

中文翻译：

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由葡萄糖基转移酶 UGT91Q2 介导的倍半萜糖基化参与调节茶树的冷胁迫耐受性。

植物在生长和发育过程中产生和释放萜烯，包括倍半萜，它们在植物中发挥不同的功能。倍半萜橙花油具有促进健康的特性，并为植物增添花香。然而，橙花醇的糖基化机制及其在植物中的生物学作用仍然未知。采用代谢物-基因相关性分析方法筛选出倍半萜烯UDP-葡萄糖基转移酶，研究其在冷应激反应中的作用。我们在茶树中发现了第一种植物UGT（UGT91Q2），它的表达受到冷胁迫的强烈诱导，并且特异性地催化橙花醇的葡萄糖基化。橙花醇苷的积累与UGT91Q2响应冷胁迫的表达水平以及不同茶品种的表达水平一致。橙花油苷的活性氧（ROS）清除能力显着高于游离橙花油。UGT91Q2的下调导致橙花醇苷的积累、活性氧清除能力和茶树耐寒性降低。茶树吸收空气中的橙花醇并将其转化为葡萄糖苷，从而增强茶树对冷胁迫的耐受性。橙花醇在应对冷应激以及触发植物与植物之间的交流以应对冷应激方面发挥作用。我们的研究结果揭示了挥发物在植物非生物胁迫响应中的先前未知作用。ROS清除能力和茶树耐寒性。茶树吸收空气中的橙花醇并将其转化为葡萄糖苷，从而增强茶树对冷胁迫的耐受性。橙花醇在应对冷应激以及触发植物与植物之间的交流以应对冷应激方面发挥作用。我们的研究结果揭示了挥发物在植物非生物胁迫响应中的先前未知作用。ROS清除能力和茶树耐寒性。茶树吸收空气中的橙花醇并将其转化为葡萄糖苷，从而增强茶树对冷胁迫的耐受性。橙花醇在应对冷应激以及触发植物与植物之间的交流以应对冷应激方面发挥作用。我们的研究结果揭示了挥发物在植物非生物胁迫响应中的先前未知作用。