State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration. College of Horticulture, Nanjing Agricultural University, 210095, Nanjing, China.
J Exp Bot. 2024 Feb 28;75(5):1479-1492. doi: 10.1093/jxb/erad451.
Ethylene-responsive factors (ERF) play an important role in plant responses to waterlogging stress. However, the function and mechanism of action of ERFVIII in response to waterlogging stress remain poorly understood. In this study, we found that expression of the ERF VIIIa gene CmERF4 in chrysanthemum was induced by waterlogging stress. CmERF4 localized to the nucleus when expressed in tobacco leaves. Yeast two-hybrid and luciferase assays showed that CmERF4 is a transcriptional inhibitor. CmERF4 overexpression in chrysanthemum reduced plant waterlogging tolerance, whereas overexpression of the chimeric activator CmERF4-VP64 reversed its transcriptional activity, promoting higher waterlogging tolerance than that observed in wild-type plants, indicating that CmERF4 negatively regulates waterlogging tolerance. Transcriptome profiling showed that energy metabolism and reactive oxygen species (ROS) pathway-associated genes were differentially expressed between CmERF4-VP64 and wild-type plants. RT-qPCR analysis of selected energy metabolism and reactive oxygen species-related genes showed that the gene expression patterns were consistent with the expression levels obtained from RNA-seq analysis. Overall, we identified new functions of CmERF4 in negatively regulating chrysanthemum waterlogging tolerance by modulating energy metabolism and ROS pathway genes.
乙烯响应因子（ERF）在植物对水淹胁迫的响应中起着重要作用。然而，ERFVIII 对水淹胁迫响应的功能和作用机制仍知之甚少。在本研究中，我们发现菊花中 ERF VIIIa 基因 CmERF4 的表达受水淹胁迫诱导。CmERF4 在烟草叶片中表达时定位于细胞核。酵母双杂交和荧光素酶报告基因 assays 表明 CmERF4 是一种转录抑制因子。菊花中 CmERF4 的过表达降低了植物的水淹耐受性，而嵌合激活子 CmERF4-VP64 的过表达逆转了其转录活性，促进了比野生型植物更高的水淹耐受性，表明 CmERF4 负调控水淹耐受性。转录组谱分析显示，能量代谢和活性氧（ROS）途径相关基因在 CmERF4-VP64 和野生型植物之间存在差异表达。对选定的能量代谢和活性氧相关基因进行 RT-qPCR 分析表明，基因表达模式与 RNA-seq 分析得到的表达水平一致。总的来说，我们确定了 CmERF4 通过调节能量代谢和 ROS 途径基因来负调控菊花水淹耐受性的新功能。
