中文摘要：

利用同源克隆和RACE-PCR获得番荔枝LEAFY基因的全长cDNA序列,命名为AsLEAFY,Gen Bank登录号为KP866145。序列分析表明,克隆获得的番荔枝AsLEAFY基因长为1 236 bp,编码411个氨基酸,该氨基酸序列含有5′-N端脯氨酸富集区和中央酸性区,具有LEAFY（FLO）家族的典型结构特征。同源分析表明,该氨基酸序列与多种木本植物LEAFY类蛋白的同源性较高。进化树分析表明AsLEAFY与木本植物的亲缘关系高于草本植物。实时定量PCR结果表明,AsLEAFY在番荔枝花发育的整个过程中都有表达,在初期的花芽中表达量最高,在不同组织器官中表达量存在差异,在枝条去叶后的腋芽中的表达量最高。推测该基因在番荔枝花器官形成初期发挥重要作用。

英文摘要：

A full-length cDNA sequence of the homologous LEAFY gene from sugar apple（Annona squamosa L.）,which was named as AsLEAFY（Gen Bank accession KP866145）,was cloned by employing homology gene cloning and RACE approaches. Sequence analysis showed that the AsLEAFY gene contains a 1 236 bp open reading frame（ORF）encoding 411 amino acids. As the typical structure features of LEAFY（FLO）family,a 5′-N praline-rich region and a central acidic region were identified in the amino acid sequence of AsLEAFY protein. The deduced AsLEAFY protein is highly homologous to the LEAFY proteins from other various woody plants. Phylogenetic tree analysis indicated that AsLEAFY shows closer relationship with the LEAFYs in woody plants than in herbs. The real-time PCR results suggested that the AsLEAFY gene could be detected during the whole period of flower development. Interestingly,AsLEAFY gene showed a high transcription level in flower bud at the beginning stage and axillary bud of fruiting branches after defoliation. It is conjectured that AsLEAFY may play a crucial role in the early stage of flower organs formation in sugar apple.