桂花OfAP1基因的克隆及表达分析

AP1（APETALA1）基因在植物花分生组织及花器官形成过程中发挥着重要作用。以桂花品种‘堰虹桂’Osmanthus fragrans‘Yanhonggui’为材料，根据前期获得的转录组数据中AP1的序列设计引物，利用PCR技术，克隆得到约750 bp桂花AP1 cDNA序列，即OfAP1基因，其中开放阅读框长为720 bp（注册号为MH593222）。氨基酸序列比对发现，与其他物种的AP1基因的同源性高达69%~88%。荧光定量PCR结果表明:在不同组织中，桂花的OfAP1基因在花芽中的表达量显著高于其他组织，根中几乎不表达；在花芽分化过程中，OfAP1在成花转变及花芽分化初期（花瓣、花萼分化期）表达量较高，随后呈下降趋势。这说明OfAP1具有组织表达特异性，同时在桂花成花转变、花芽分化和发育中有重要作用。

cDNA cloning and expression analysis of OfAP1 in Osmanthus fragrans

Osmanthus fragrans is one of the top ten traditional flowers and a common landscaping tree in China. To better understand the function of AP1 in regulation of Osmanthus flowering, the OfAP1 gene was cloned from the Osmanthus cultivator 'Yanhonggui', and its function was analyzed through bioinformatics method and real time PCR. Our results showed that the cDNA length of OfAP1 was 750 bp (GenBank accession No. MH593222), in which the Open Reading Frame length was 720 bp, the amino acid was 239. The OfAP1 sequence alignment revealed high homology with other species ranging from 69% to 88%. Additionally, expression profiles showed that the expression of OfAP1 in flower buds was much higher than that in other tissues (root, stem, leaf, leaf bud and flower), and the expression was barely expressed in roots. During the development of flower bud, the OfAP1 showed higher expression in S1 (calyx and petal differentiation) stage than other stages. Thus, these results suggested that OfAP1 had a tissue specific expression and played an important role in flowering transformation, flower bud differentiation, and development of O. fragrans. And the results of OfAP1 can lay a foundation for further study of the molecular mechanism of O. fragrans.