College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
J Exp Bot. 2011 Jan;62(2):825-40. doi: 10.1093/jxb/erq324. Epub 2010 Oct 25.
Ethylene-responsive element-binding factor (ERF) genes constitute one of the largest transcription factor gene families in plants. In Arabidopsis and rice, only a few ERF genes have been characterized so far. Flower senescence is associated with increased ethylene production in many flowers. However, the characterization of ERF genes in flower senescence has not been reported. In this study, 13 ERF cDNAs were cloned from petunia. Based on the sequence characterization, these PhERFs could be classified into four of the 12 known ERF families. Their predicted amino acid sequences exhibited similarities to ERFs from other plant species. Expression analyses of PhERF mRNAs were performed in corollas and gynoecia of petunia flower. The 13 PhERF genes displayed differential expression patterns and levels during natural flower senescence. Exogenous ethylene accelerates the transcription of the various PhERF genes, and silver thiosulphate (STS) decreased the transcription of several PhERF genes in corollas and gynoecia. PhERF genes of group VII showed a strong association with the rise in ethylene production in both petals and gynoecia, and might be associated particularly with flower senescence in petunia. The effect of sugar, methyl jasmonate, and the plant hormones abscisic acid, salicylic acid, and 6-benzyladenine in regulating the different PhERF transcripts was investigated. Functional nuclear localization signal analyses of two PhERF proteins (PhERF2 and PhERF3) were carried out using fluorescence microscopy. These results supported a role for petunia PhERF genes in transcriptional regulation of petunia flower senescence processes.
乙烯响应元件结合因子（ERF）基因是植物中最大的转录因子基因家族之一。在拟南芥和水稻中，到目前为止只对少数 ERF 基因进行了描述。许多花卉的衰老与乙烯生成增加有关。然而，在花衰老过程中 ERF 基因的特征尚未报道。在这项研究中，从矮牵牛中克隆了 13 个 ERF cDNA。根据序列特征，这些 PhERFs 可以分为 12 个已知 ERF 家族中的 4 个。它们预测的氨基酸序列与其他植物物种的 ERFs 相似。在矮牵牛花的花瓣和雌蕊中进行了 PhERF mRNA 的表达分析。在自然花衰老过程中，13 个 PhERF 基因表现出不同的表达模式和水平。外源乙烯加速了各种 PhERF 基因的转录，而银硫代硫酸（STS）降低了花瓣和雌蕊中几种 PhERF 基因的转录。第 VII 组的 PhERF 基因与花瓣和雌蕊中乙烯生成的增加密切相关，可能与矮牵牛的花衰老特别相关。研究了糖、茉莉酸甲酯以及植物激素脱落酸、水杨酸和 6-苄基腺嘌呤对不同 PhERF 转录物的调节作用。使用荧光显微镜对两种 PhERF 蛋白（PhERF2 和 PhERF3）进行了功能核定位信号分析。这些结果支持矮牵牛 PhERF 基因在矮牵牛花衰老过程的转录调控中的作用。
