一氧化碳增强高温诱导的烟草中尼古丁的生物合成。

Carbon Monoxide Potentiates High Temperature-Induced Nicotine Biosynthesis in Tobacco.

机构信息

Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing 210037, China.

College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China.

出版信息

Int J Mol Sci. 2018 Jan 8;19(1):188. doi: 10.3390/ijms19010188.

Carbon monoxide (CO) acts as an important signal in many physiological responses in plants, but its role in plant secondary metabolism is still unknown. Nicotine is the main alkaloid generated in tobacco and the plant hormone jasmonic acid (JA) has previously been reported to efficiently induce its biosynthesis. Whether and how CO interacts with JA to regulate nicotine biosynthesis in tobacco remains elusive. In this study, we demonstrate that high temperature (HT) induces quick accumulation of nicotine in tobacco roots, combined with an increase in CO and JA concentration. Suppressing CO generation reduced both JA and nicotine biosynthesis, whereas exogenous application of CO increased JA and nicotine content. CO causes an increased expression of (a key nicotine biosynthesis enzyme), via promoting NtMYC2a binding to the G-box region of its promoter, leading to heightened nicotine levels under HT conditions. These data suggest a novel function for CO in stimulating nicotine biosynthesis in tobacco under HT stress, through a JA signal.

一氧化碳（CO）在植物的许多生理反应中充当着重要的信号分子，但它在植物次生代谢中的作用尚不清楚。尼古丁是烟草中生成的主要生物碱，先前有报道表明植物激素茉莉酸（JA）能有效地诱导其生物合成。CO 是否以及如何与 JA 相互作用来调节烟草中的尼古丁生物合成仍然难以捉摸。在本研究中，我们证明了高温（HT）诱导烟草根中尼古丁的快速积累，同时伴随着 CO 和 JA 浓度的增加。抑制 CO 的产生会降低 JA 和尼古丁的生物合成，而外源 CO 的应用则会增加 JA 和尼古丁的含量。CO 通过促进 NtMYC2a 结合到其启动子的 G 盒区域，导致关键的尼古丁生物合成酶的表达增加，从而在 HT 条件下提高尼古丁水平。这些数据表明，CO 通过 JA 信号在高温胁迫下刺激烟草中的尼古丁生物合成具有新的功能。