PDF(Pubmed)
Abstract：
The gaseous phytohormone ethylene plays a crucial role in plant growth, development, and stress responses. In the ethylene signal transduction cascade, the F-box proteins EIN3-BINDING F-BOX 1 (EBF1) and EBF2 are identified as key negative regulators governing ethylene sensitivity. The translation and processing of EBF1/2 mRNAs are tightly controlled, and their 3\' untranslated regions (UTRs) are critical in these regulations. However, despite their significance, the exact mechanisms modulating the processing of EBF1/2 mRNAs remain poorly understood. In this work, we identified the gene DCP1-ASSOCIATED NYN ENDORIBONUCLEASE 1 (DNE1), which encodes an endoribonuclease and is induced by ethylene treatment, as a positive regulator of ethylene response. The loss of function mutant dne1-2 showed mild ethylene insensitivity, highlighting the importance of DNE1 in ethylene signaling. We also found that DNE1 colocalizes with ETHYLENE INSENSITIVE 2 (EIN2), the core factor manipulating the translation of EBF1/2, and targets the P-body in response to ethylene. Further analysis revealed that DNE1 negatively regulates the abundance of EBF1/2 mRNAs by recognizing and cleaving their 3\'UTRs, and it also represses their translation. Moreover, the dne1 mutant displays hypersensitivity to 1,4-dithiothreitol (DTT)-induced ER stress and oxidative stress, indicating the function of DNE1 in stress responses. This study sheds light on the essential role of DNE1 as a modulator of ethylene signaling through regulation of EBF1/2 mRNA processing. Our findings contribute to the understanding of the intricate regulatory process of ethylene signaling and provide insights into the significance of ribonuclease in stress responses.
摘要：
气态植物激素乙烯在植物生长中起着至关重要的作用,发展,和应激反应。在乙烯信号转导级联反应中，F盒蛋白EIN3结合F盒1（EBF1）和EBF2被鉴定为控制乙烯敏感性的关键负调节剂。EBF1/2mRNA的翻译和加工受到严格控制，它们的3个未翻译区域(UTR)在这些法规中至关重要。然而,尽管意义重大,调节EBF1/2mRNA加工的确切机制仍然知之甚少。在这项工作中,我们鉴定了基因DCP1相关的NYN内切酶1（DNE1），它编码核糖核酸内切酶，由乙烯处理诱导，作为乙烯反应的正调节剂。功能缺失突变体dne1-2显示轻度乙烯不敏感，强调DNE1在乙烯信号传导中的重要性。我们还发现DNE1与乙烯不敏感2（EIN2）共定位，操纵EBF1/2翻译的核心因素，并针对P体响应乙烯。进一步的分析显示，DNE1通过识别和切割它们的3个UTR负调节EBF1/2mRNA的丰度，它也抑制了他们的翻译。此外，dne1突变体对1,4-二硫苏糖醇（DTT）诱导的ER应激和氧化应激表现出超敏反应，表明DNE1在应激反应中的作用。这项研究揭示了DNE1通过调节EBF1/2mRNA加工作为乙烯信号调节剂的重要作用。我们的发现有助于理解乙烯信号传导的复杂调控过程，并提供对核糖核酸酶在应激反应中的重要性的见解。
