Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China.
Plant Cell Rep. 2019 Jun;38(6):699-714. doi: 10.1007/s00299-019-02398-x. Epub 2019 Mar 4.
An ICE-like transcription factor mediates jasmonate-regulated cold tolerance in the rubber tree (Hevea brasiliensis), and confers cold tolerance in transgenic Arabidopsis. The rubber tree (Hevea brasiliensis) is susceptible to low temperatures, and understanding the mechanisms regulating cold stress is of great potential value for enhancing tolerance to this environmental variable. In this study, we find that treatment with exogenous methyl jasmonate (MeJA) could significantly enhance Hevea brasiliensis cold tolerance. In addition, yeast two-hybrid and bimolecular fluorescence complementation (BiFC) experiments show that JASMONATE ZIM-DOMAIN(JAZ) proteins, HbJAZ1 and HbJAZ12, key repressors of JA signaling pathway, interact with HbICE2, a novel ICE (Inducer of CBF Expression)-like protein. HbICE2 was nuclear-localised and bound to the MYC recognition (MYCR) sequence. The transcriptional activation activity of HbICE2 in yeast cells was dependent on the N-terminus, and overexpression of HbICE2 in Arabidopsis resulted in elevated tolerance to chilling stress. Furthermore, dual-luciferase transient assay reveals that HbJAZ1 and HbJAZ12 proteins inhibit the transcriptional function of HbICE2. The expression of C-repeat-binding factor (CBF) signalling pathway genes including HbCBF1, HbCBF2 and HbCOR47 were up-regulated by MeJA. Taken together, our data suggest that the new ICE-like transcription factor HbICE2 is involved in jasmonate-regulated cold tolerance in Hevea brasiliensis.
一种 ICE 样转录因子介导了橡胶树（Hevea brasiliensis）中茉莉酸调控的耐寒性，并且在转基因拟南芥中赋予了耐寒性。橡胶树（Hevea brasiliensis）对低温敏感，理解调节冷应激的机制对于增强对这种环境变量的耐受性具有巨大的潜在价值。在本研究中，我们发现外源茉莉酸甲酯（MeJA）处理可以显著增强橡胶树的耐寒性。此外，酵母双杂交和双分子荧光互补（BiFC）实验表明，茉莉酸 ZIM 结构域（JAZ）蛋白 HbJAZ1 和 HbJAZ12，是 JA 信号通路的关键抑制因子，与 HbICE2 相互作用，HbICE2 是一种新型的 ICE（CBF 表达诱导物）样蛋白。HbICE2 定位于细胞核，并与 MYC 识别（MYCR）序列结合。HbICE2 在酵母细胞中的转录激活活性依赖于 N 端，并且在拟南芥中过表达 HbICE2 导致对冷胁迫的耐受性提高。此外，双荧光素酶瞬时测定显示 HbJAZ1 和 HbJAZ12 蛋白抑制 HbICE2 的转录功能。包括 HbCBF1、HbCBF2 和 HbCOR47 在内的 C 重复结合因子（CBF）信号通路基因的表达被 MeJA 上调。总之，我们的数据表明，新型 ICE 样转录因子 HbICE2 参与了橡胶树中茉莉酸调控的耐寒性。
