Solano R, Stepanova A, Chao Q, Ecker J R
Department of Biology, Plant Science Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018 USA.
Genes Dev. 1998 Dec 1;12(23):3703-14. doi: 10.1101/gad.12.23.3703.
Response to the gaseous plant hormone ethylene in Arabidopsis requires the EIN3/EIL family of nuclear proteins. The biochemical function(s) of EIN3/EIL proteins, however, has remained unknown. In this study, we show that EIN3 and EILs comprise a family of novel sequence-specific DNA-binding proteins that regulate gene expression by binding directly to a primary ethylene response element (PERE) related to the tomato E4-element. Moreover, we identified an immediate target of EIN3, ETHYLENE-RESPONSE-FACTOR1 (ERF1), which contains this element in its promoter. EIN3 is necessary and sufficient for ERF1 expression, and, like EIN3-overexpression in transgenic plants, constitutive expression of ERF1 results in the activation of a variety of ethylene response genes and phenotypes. Evidence is also provided that ERF1 acts downstream of EIN3 and all other components of the ethylene signaling pathway. The results demonstrate that the nuclear proteins EIN3 and ERF1 act sequentially in a cascade of transcriptional regulation initiated by ethylene gas.
拟南芥对气态植物激素乙烯的响应需要EIN3/EIL家族的核蛋白。然而，EIN3/EIL蛋白的生化功能仍不清楚。在本研究中，我们表明EIN3和EILs构成了一个新的序列特异性DNA结合蛋白家族，它们通过直接结合与番茄E4元件相关的主要乙烯反应元件（PERE）来调节基因表达。此外，我们鉴定出EIN3的一个直接靶标，即乙烯反应因子1（ERF1），其启动子中含有该元件。EIN3对于ERF1的表达是必需且充分的，并且与转基因植物中EIN3的过表达一样，ERF1的组成型表达导致多种乙烯反应基因的激活和表型。还提供了证据表明ERF1在EIN3和乙烯信号通路的所有其他组分的下游起作用。结果表明，核蛋白EIN3和ERF1在由乙烯气体引发的转录调控级联反应中依次发挥作用。
