Cai Wenguo, Li Xiaojuan, Liu Yanlin, Wang Yaowei, Zhou Yue, Xu Tongda, Xiong Yan
a Horticultural Plant Biology and Metabolomics Center, Haixia Institute of Science and Technology , Fujian Agriculture and Forestry University , Fujian Province , P. R. China.
b Shanghai Center for Plant Stress Biology, Chinese Academy of Science Center for Excellence in Molecular Plant Sciences , Chinese Academy of Sciences , Shanghai , P. R. China.
Plant Signal Behav. 2017 Sep 2;12(9):e1363946. doi: 10.1080/15592324.2017.1363946. Epub 2017 Aug 14.
The exquisite regulation of cell division at the shoot apex according to the external environmental cues enables plants to adapt the ever-changing environment. We have recently shown that light direct signaling and carbohydrate (sugar) energy signaling are both essential for the activation of cell division at the shoot apex. Light is converted to auxin signal to activate small GTPase 2 (ROP2). Subsequently, the activated ROP2 directly interacts with Target of Rapamycin (TOR) protein kinase, a pivotal regulator of cell division, to promote its kinase activity. However, neither light nor auxin alone can activate TOR kinase without the presence of sugar. In this addendum, we showed that Constitutive Photomorphogenesis 1 (COP1) acts as an upstream factor of ROP2. COP1 regulates ROP2 and TOR activity in an auxin dependent manner. The development of true leaves in the cop1-6 mutant under darkness is compromised by auxin biosynthesis inhibitor yucasin and TOR chemical inhibitor torin2. Together, our results suggested that COP1 regulates auxin-ROP2-TOR signaling in response to light.
根据外部环境线索对茎尖细胞分裂进行的精确调控，使植物能够适应不断变化的环境。我们最近发现，光直接信号传导和碳水化合物（糖）能量信号传导对于茎尖细胞分裂的激活都是必不可少的。光被转化为生长素信号以激活小GTP酶2（ROP2）。随后，激活的ROP2直接与细胞分裂的关键调节因子雷帕霉素靶蛋白（TOR）蛋白激酶相互作用，以促进其激酶活性。然而，在没有糖的情况下，光和生长素单独都不能激活TOR激酶。在本附录中，我们表明组成型光形态建成1（COP1）作为ROP2的上游因子。COP1以生长素依赖的方式调节ROP2和TOR活性。生长素生物合成抑制剂玉蜀黍素和TOR化学抑制剂托林2损害了黑暗条件下cop1-6突变体中真叶的发育。总之，我们的结果表明COP1响应光调节生长素-ROP2-TOR信号传导。
