Kidokoro Satoshi, Yoneda Koshi, Takasaki Hironori, Takahashi Fuminori, Shinozaki Kazuo, Yamaguchi-Shinozaki Kazuko
Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
Gene Discovery Research Group, RIKEN Centre for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan.
Plant Cell. 2017 Apr;29(4):760-774. doi: 10.1105/tpc.16.00669. Epub 2017 Mar 28.
In plants, cold temperatures trigger stress responses and long-term responses that result in cold tolerance. In , three dehydration-responsive element (DRE) binding protein 1/C-repeat binding factors (DREB1/CBFs) act as master switches in cold-responsive gene expression. Induction of genes triggers the cold stress-inducible transcriptional cascade, followed by the induction of numerous genes that function in the cold stress response and cold tolerance. Many regulatory factors involved in induction have been identified, but how these factors orchestrate the cold stress-specific expression of has not yet been clarified. Here, we revealed that plants recognize cold stress as two different signals, rapid and gradual temperature decreases, and induce expression of the genes. CALMODULIN BINDING TRANSCRIPTION ACTIVATOR3 (CAMTA3) and CAMTA5 respond to a rapid decrease in temperature and induce the expression of , but these proteins do not respond to a gradual decrease in temperature. Moreover, they function during the day and night, in contrast to some key circadian components, including CIRCADIAN CLOCK ASSOCIATED1 and LATE ELONGATED HYPOCOTYL, which regulate cold-responsive expression as transcriptional activators only during the day. Thus, plants efficiently control the acquisition of freezing tolerance using two different signaling pathways in response to a gradual temperature decrease during seasonal changes and a sudden temperature drop during the night.
在植物中，低温会触发应激反应和长期反应，从而导致耐寒性。在[具体植物名称未给出]中，三种脱水响应元件（DRE）结合蛋白1/C重复结合因子（DREB1/CBFs）在冷响应基因表达中起主控开关的作用。这些基因的诱导触发了冷应激诱导的转录级联反应，随后诱导了许多在冷应激反应和耐寒性中起作用的基因。已经鉴定出许多参与这些基因诱导的调控因子，但这些因子如何协调这些基因的冷应激特异性表达尚未阐明。在这里，我们揭示植物将冷应激识别为两种不同的信号，即温度的快速下降和逐渐下降，并诱导这些基因的表达。钙调蛋白结合转录激活因子3（CAMTA3）和CAMTA5对温度的快速下降作出反应并诱导这些基因的表达，但这些蛋白质对温度的逐渐下降没有反应。此外，它们在白天和黑夜都发挥作用，这与一些关键的昼夜节律成分不同，包括昼夜节律相关蛋白1（CIRCADIAN CLOCK ASSOCIATED1）和晚伸长下胚轴（LATE ELONGATED HYPOCOTYL），它们仅在白天作为转录激活因子调节冷响应基因的表达。因此，植物通过两种不同的信号通路有效地控制耐寒性的获得，以应对季节性变化期间温度的逐渐下降和夜间温度的突然下降。
