UV-B irradiation differentially regulates terpene synthases and terpene content of peach
UV-B irradiation differentially regulates terpene synthases and terpene content of peach
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DOI：
10.1111/pce.13029
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发表时间：
2017-10-01
影响因子：
7.3
通讯作者：
Chen, Kunsong
中科院分区：
文献类型：
--
作者：
Liu, Hongru;Cao, Xiangmei;Chen, Kunsong
植物对紫外线(UV)光做出反应时会产生保护性分子。在实验室实验中，48h的UV-B辐射使桃子果实和叶片中与风味相关的单萜芳樟醇减少了60%。没有检测到异戊二烯，但其他萜类化合物显著增加，包括倍半萜(E，E)-α-法尼烯的积累，这也被茉莉酸处理增加了三倍。RNA测序显示两个萜烯合成酶(TPSS)的转录水平发生了变化：TPS-g亚家族成员PpTPS1减少了86%，TPS-b亚家族成员PpTPS2增加了80倍。在大肠杆菌中的异源表达和在烟草和桃果实中的瞬时过表达表明，PpTPS1定位于叶绿体中，并与芳樟醇的产生有关，而PpTPS2负责(E，E)-α-法尼烯在细胞质中的生物合成。确定了这些反应的候选调控基因。在亚洲，桃子的商业生产包括套袋以保持适销对路的产量和质量。在田间试验中，利用传输高UV-B辐射的袋子，TPS基因表达和挥发性萜类化合物的产生对桃子挥发物的影响与实验室试验相似。通过较少的UV-B光透射袋，改善了桃果实风味挥发性芳樟醇的减少，这表明可以通过选择合适的环境筛选材料来源来调节桃果实的风味成分。
Plants generate protective molecules in response to ultraviolet (UV) light. In laboratory experiments, 48h UV-B irradiation of peach fruits and leaves reduced the flavour-related monoterpene linalool by 60%. No isoprene was detected, but other terpenoids increased significantly, including a threefold accumulation of the sesquiterpene (E,E)-alpha-farnesene, which was also increased by jasmonic acid treatment. RNA sequencing revealed altered transcript levels for two terpene synthases (TPSs): PpTPS1, a TPS-g subfamily member, decreased by 86% and PpTPS2, a TPS-b subfamily member, increased 80-fold. Heterologous expression in Escherichia coli and transient overexpression in tobacco and peach fruits showed PpTPS1 was localized in plastids and associated with production of linalool, while PpTPS2 was responsible for (E,E)-alpha-farnesene biosynthesis in the cytoplasm. Candidate regulatory genes for these responses were identified. Commercial peach production in Asia involves fruit bagging to maintain marketable yield and quality. TPS gene expression and volatile terpenoid production in field experiments, using bags transmitting high UV-B radiation, showed similar effects on peach volatiles to those from laboratory experiments. Bags transmitting less UV-B light ameliorated the reduction in the flavour volatile linalool, indicating that flavour components of peach fruits can be modulated by selecting an appropriate source of environmental screening material.