Metabolite-mediated TOR signaling regulates the circadian clock in Arabidopsis

First author: Nan Zhang; Affiliations: CAS Center for Excellence in Molecular Plant Sciences (中科院分子植物科学卓越创新中心): Shanghai, China

Corresponding author: Yan Xiong

Circadian clocks usually run with a period close to 24 h, but are also plastic and can be entrained by external environmental conditions and internal physiological cues. Two key nutrient metabolites, glucose and vitamin B3 (nicotinamide; 烟酰胺), can influence the circadian period in both mammals and plants; however, the underlying molecular mechanism is still largely unclear. We reveal that the target of rapamycin (TOR) kinase, a conserved central growth regulator, is essential for glucose- and nicotinamide-mediated control of the circadian period in Arabidopsis. Nicotinamide affects the cytosolic adenosine triphosphate (三磷酸腺苷) concentration, and blocks the effect of glucose-TOR energy signaling on period length adjustment, meristem activation, and root growth. Together, our results uncover a missing link between cellular metabolites, energy status, and circadian period adjustment, and identify TOR kinase as an essential energy sensor to coordinate circadian clock and plant growth.

生物钟节律通常以24小时为一个运行周期，但也具有可塑性，外界环境条件和内部生理信号可能会牵制着生物钟节律。两个关键的营养代谢物：葡萄糖和维生素B3（即烟酰胺）在动植物中均能影响生物钟周期；然而，具体的分子调控机制还不清楚。本文中，作者揭示了一个保守的核心生长调控因子雷帕霉素靶蛋白（TOR）激酶对于拟南芥中葡萄糖和烟酰胺介导的生物钟周期调控是必须的。烟酰胺会影响胞质中三磷酸腺苷的浓度，从而阻断了葡糖-TOR能量信号通路对于生物钟周期长度调整、分生组织激活以及根生长的影响。综上，本文的研究揭示了一个未曾报道的细胞代谢物、能量状态和生物钟周期调控之间的联系网络，并且鉴定了TOR激酶作为一个必不可少的能量感受器，作用于生物钟与植物生长之间的协调运行。

通讯：熊延 (http://net.fafu.edu.cn/bfpc/fb/0f/c10164a260879/page.htm)

个人简介：2006年，美国爱荷华州立大学，博士；哈佛医学院，博士后。

研究方向：植物营养信号传导调控及抗逆。 

doi: https://doi.org/10.1073/pnas.1913095116

Journal: PNAS

Published date: December 02, 2019