背景回顾：Waterlogging stress affects plant growth by limiting root respiration and reducing yield and economic value. Therefore, identifying genes involved in regulating waterlogging stress is vital. 

主要发现：This study reports the ethylene-response VII transcription factor (CmRAP2.3) in chrysanthemum. 

结果1-转录因子活性：Subcellular localization and transactivation assay analyses revealed that CmRAP2.3 was localized in the nucleus and possessed transactivation activity. 

结果2-RAP2.3过表达：Overexpression of CmRAP2.3 in chrysanthemum was found to enhance waterlogging tolerance by decreasing reactive oxygen species (ROS) levels. 

结果3-ERF5-RAP2.3：Furthermore, we found that the transcription factor CmERF5 binds to GCC-like motif in the CmRAP2.3 promoter region and activates CmRAP2.3 expression. 

结果4-ERF5过表达：Additionally, CmERF5 overexpression maintained a low ROS level and improved chrysanthemum waterlogging tolerance. 

结论：Taken together, this study shows a molecular mechanism by which CmERF5 transcriptionally activates CmRAP2.3 to reduce waterlogging stress via the ROS pathway in chrysanthemum.

Schematic model of the role of CmERF5-CmRAP2.3 transcriptional cascade in the modulation of chrysanthemum waterlogging tolerance.

水淹胁迫通过限制根系呼吸来影响植物的生长，导致产量的减少，最终降低经济价值。因此，鉴定参与调控水淹胁迫的基因十分重要。本文中，作者报道了菊花乙烯响应VII转录因子CmRAP2.3。亚细胞定位和反式激活分析表明，CmRAP2.3定位于细胞核并具有反式激活活性。在菊花中过表达CmRAP2.3可以降低活性氧（ROS）水平，从而增强植株的耐涝性。此外，作者还发现转录因子CmERF5可以结合到CmRAP2.3基因启动子区的GCC基序上，从而激活CmRAP2.3基因的表达。另外，CmERF5的过表达会是植株维持较低的活性氧水平，从而提高了菊花的耐涝性。综上，本文的研究结果揭示了CmERF5通过转录激活CmRAP2.3，从而控制菊花在水淹胁迫下的ROS水平，最终增强菊花对水淹胁迫的抗性。

** 陈发棣 **