Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan.
Plant Physiol. 2013 Jul;162(3):1566-82. doi: 10.1104/pp.113.221911. Epub 2013 May 29.
ETHYLENE RESPONSE FACTOR1 (ERF1) is an upstream component in both jasmonate (JA) and ethylene (ET) signaling and is involved in pathogen resistance. Accumulating evidence suggests that ERF1 might be related to the salt stress response through ethylene signaling. However, the specific role of ERF1 in abiotic stress and the molecular mechanism underlying the signaling cross talk still need to be elucidated. Here, we report that ERF1 was highly induced by high salinity and drought stress in Arabidopsis (Arabidopsis thaliana). The salt stress induction required both JA and ET signaling but was inhibited by abscisic acid. ERF1-overexpressing lines (35S:ERF1) were more tolerant to drought and salt stress. They also displayed constitutively smaller stomatal aperture and less transpirational water loss. Surprisingly, 35S:ERF1 also showed enhanced heat tolerance and up-regulation of heat tolerance genes compared with the wild type. Several suites of genes activated by JA, drought, salt, and heat were found in microarray analysis of 35S:ERF1. Chromatin immunoprecipitation assays found that ERF1 up-regulates specific suites of genes in response to different abiotic stresses by stress-specific binding to GCC or DRE/CRT. In response to biotic stress, ERF1 bound to GCC boxes but not DRE elements; conversely, under abiotic stress, we observed specific binding of ERF1 to DRE elements. Furthermore, ERF1 bound preferentially to only one among several GCC box or DRE/CRT elements in the promoter region of its target genes. ERF1 plays a positive role in salt, drought, and heat stress tolerance by stress-specific gene regulation, which integrates JA, ET, and abscisic acid signals.
乙烯应答因子 1（ERF1）是茉莉酸（JA）和乙烯（ET）信号转导的上游组成部分，参与病原体抗性。越来越多的证据表明，ERF1 可能通过乙烯信号与盐胁迫反应有关。然而，ERF1 在非生物胁迫中的具体作用以及信号串扰的分子机制仍有待阐明。在这里，我们报道 ERF1 在拟南芥中高度诱导高盐和干旱胁迫。盐胁迫诱导需要 JA 和 ET 信号，但被脱落酸抑制。ERF1 过表达系（35S:ERF1）对干旱和盐胁迫更耐受。它们还表现出持续较小的气孔开度和较少的蒸腾水分损失。令人惊讶的是，与野生型相比，35S:ERF1 还表现出增强的耐热性和热耐性基因的上调。在 35S:ERF1 的微阵列分析中发现了 JA、干旱、盐和热激活的几套基因。染色质免疫沉淀测定发现 ERF1 通过应激特异性结合 GCC 或 DRE/CRT 来上调对不同非生物胁迫的特定基因。在应对生物胁迫时，ERF1 结合 GCC 盒而不结合 DRE 元件；相反，在非生物胁迫下，我们观察到 ERF1 特异性结合 DRE 元件。此外，ERF1 在其靶基因启动子区域中仅优先结合 GCC 盒或 DRE/CRT 元件中的一个。ERF1 通过应激特异性基因调控在盐、干旱和耐热性方面发挥积极作用，整合了 JA、ET 和脱落酸信号。
