【目的】牡丹(Paeonia×suffruticosa)是传统的观赏名花,由于其花期短暂极大限制了牡丹的观赏价值。克隆牡丹品种‘凤丹’(Paeonia ostii ‘Feng Dan’)PoERF4基因,研究其序列特征及在不同花期、组织、品种和激素处理下的表达特性,为进一步研究PoERF4基因对牡丹花期和生长发育的调控作用提供理论参考。【方法】以‘凤丹’为研究材料,基于‘凤丹’3代全长转录组测序结果,筛选出同源性高的序列,采用RT-PCR技术克隆PoERF4基因,并进行生物信息学和表达模式分析。【结果】PoERF4基因的开放阅读框(ORF)为747 bp,编码248个氨基酸。PoERF4蛋白分子式为C_{2 217}H_{3 689}N₇₄₇O₉₃₃S₁₇₄,为亲水蛋白,含有保守的AP2超家族结构域,无跨膜结构,二级结构中α-螺旋中包含28个氨基酸,延伸链中包含48个氨基酸, β-转角中包含6个氨基酸。荧光定量分析发现,PoERF4基因在‘凤丹’不同花期的花瓣中,半开期的表达量最高;在不同组织中均有表达,但其在叶片中表达量最高,花瓣次之,根中表达量最低;在3个不同品种中,晚花品种‘莲鹤’‘Lianhe’中表达量最高;在生长素处理下,PoERF4基因能够对其产生应答。【结论】从‘凤丹’中成功分离出PoERF4基因,推测其在花和叶片发育进程中起重要调控作用,参与‘凤丹’生长素信号转导过程。

【Objective】 Paeonia×suffruticosa (peony) is a traditional ornamental flower. Because its short flowering period greatly limits the ornamental value of peony, the PoERF4 gene of ostii ‘Feng Dan’ was cloned to study its sequence and expression characteristics in different flowering periods, tissues, varieties and hormone treatments. This study aimed to provide a theoretical reference for further research on the regulation of PoERF4 during the flowering, growth and development of tree peony. 【Method】 Using ‘Feng Dan’ as the material, based on the results of the three-generation full-length transcriptome sequencing of ‘Feng Dan’, the sequences with high homology were screened, the PoERF4 gene was cloned by RT-PCR technology, and bioinformatics and expression pattern analysis were performed. 【Result】The open read frame (ORF) of the PoERF4 gene was 747 bp, which encoded 248 amino acids. The molecular formula of PoERF4 was C_{2 217}H_{3 689}N₇₄₇O₉₃₃S₁₇₄, which is a hydrophilic protein containing a conserved AP2 superfamily domain with no transmembrane structure. The secondary structure contained 28 amino acids in the α-helix, 48 amino acids in the extended chain, and six amino acids in the β-turn. Fluorescence quantitative analysis found that the PoERF4 gene was mainly expressed in the petals of the half-opening period of ‘Feng Dan’ and it was expressed in different tissues of ‘Feng Dan’ peony, but its expression was highest in the leaves, followed by in the petals and roots. The expression level was the highest in the late-flower cultivar ‘Lianhe’. Under auxin treatment, the PoERF4 gene could respond. 【Conclusion】The PoERF4 gene was successfully isolated from ‘Feng Dan’ and it was speculated that it plays an important regulatory role in the development of flowers and leaves and is involved in the auxin signal transduction process of ‘Feng Dan’.