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作 者 ：张计育，宣继萍，贾晓东，刘永芝，王 翔，郭忠仁*

期 刊 ：西北植物学报 2012年 7期 页码：1309~1315

关键词：富士苹果；MdAPETALA2；基因克隆；启动子；表达模式；

Keywords:Fuji apple, MdAPETALA2, gene cloning, promoter, expression pattern,

摘 要 ：基于苹果基因组测序序列，从‘长富6号’富士苹果中分离了MdAPETALA2基因序列，通过生物信息学方法分析结构特征，利用实时荧光定量RT PCR技术研究其在不同器官中的表达特性。结果表明：（1）MdAPETALA2基因cDNA序列为1 614 bp，该基因最大开放阅读框为1 389 bp，编码462个氨基酸，含有2个保守的AP2结构域和核定位信号；其编码区含有8个内含子和9个外显子；启动子区域含有许多光响应元件，如ATCT motif、G Box、GA motif、I box、Sp1、TCCC motif等，以及水杨酸响应元件、赤霉素响应元件、防御和逆境响应元件等。（2）MdAPETALA2基因在苹果各种器官中均有表达，但不同组织中表达量存在差异，在种子中的表达量最高，其次是根和花，在叶和茎中的表达量最低；在花药中的表达量最大，其次是花托和子房，在花瓣、花梗和花柱中的表达量相对较少。（3）苹果MdAPETALA2基因属于AP2亚族，可能在种子的发育过程中起着非常重要的作用。

Abstract:Based on the apple complete genomic sequences,the full length cDNA,genomic DNA and promoter sequences of MdAPETALA2 were isolated from the Fuji apple.Gene structure characterizations were analyzed using the bioinformatics software.Real time quantitative PCR (qRT PCR) was performed to determine the expression pattern of MdAPETALA2 in different tissues of apple.1 614 bp cDNA sequence of MdAPETALA2 was cloned.Bioinformatics analysis showed that the open reading frame of this gene was 1 369 bp,encoding 462 amino acids,containing two conservative AP2 structure domains and nuclear location signal.This gene contains 8 introns and 9 exons.The promoter has many light responsive elements,such as ATCT motif,G Box,GA motif,I box,Sp1,TCCC motif,and so on.Moreover,salicylic acid responsiveness,defense and stress responsiveness,and drought inducibility were found in promoter of MdAPETALA2.Expression analysis showed that the expression of MdAPETALA2 gene was detected in all kinds of tissues of apple.But the expression levels were different;the expression level of this gene was higher in seeds,medium in roots and flowers,and lower in leaves,stems.And the expression level of MdAPETALA2 gene was higher in anther,medium in receptacle and ovary,lower in petal,peduncle and style.MdAPETALA2 gene is belonging to AP2 subfamily,and plays an important role in the procedure of seeds developing.

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