Abstract: ERFs are downstream component in ethylene signaling and involves in plant responses to ethylene. In this study, an ERF gene, designated as ZmERF1,  was isolated from 20 DAP endosperm of inbred Dan232 (Zea mays L.) and its  sequence and expression characteristics were analyzed. ZmERF1 contains 811 bp with a 690 bp ORF, and encodes 230 aa with a single conserved AP2 domain. Online protein structure prediction revealed that there are three β-sheets and one α-helix in the AP2 domain. The ZmERF1 localized in the nucleus by online protein prediction. ZmERF1 was closely homologous with sorghum SbERF and rice OsERF. Prokaryotic expression  and Western Blot analysis showed that  ZmERF1 proteins could be obtained in vitro. The expression level of ZmERF1 proteins  in early-stage  was lower than that in later-stage of endosperm (36 DAP) in Dan232. ZmERF1 may play a key role in later-stage of endosperm development in maize. The results of this work uncovered characteristics of ERFs in maize, and provided a basic for exploring their biological functions in grains development.

Key words: AP2/EREBP family, ZmERF1, qPCR, Western Blot

摘要： ERF类转录因子是乙烯信号转导途径中的下游响应因子，参与乙烯调控的多种生理生化反应。从玉米自交系丹232授粉后20 d的胚乳中克隆了一个ERF类转录因子ZmERF1，并对其进行了序列及表达分析。结果显示，ZmERF1基因全长811 bp，ORF 690 bp，编码230个氨基酸，包含一个典型的AP2结构域,含有3个α-helix和1个β-sheets，亚细胞定位于细胞核中。进化树分析表明该基因与单子叶高粱SbERF和水稻OsERF同源性较高。在体外原核表达系统中能够检测到重组蛋白His-ZmERF1，并用Western Blot验证了所表达蛋白为重组蛋白，表明该基因具有体外活性。荧光定量PCR分析表明该基因在胚乳发育的前期表达量较少，后期(36 d)表达量较高。进一步对胚乳总蛋白的定量Western Blot分析，表明该蛋白在胚乳发育后期积累量高于发育前期。因此，初步推测玉米ZmERF1可能在籽粒胚乳发育后期发挥重要作用。该研究结果为了解该基因家族转录因子并进一步阐明其生物学功能提供了依据。

关键词: AP2/EREBP类转录因子, ZmERF1, 荧光定量PCR, Western Blot