苹果生长素响应因子(ARF)基因家族全基因组鉴定及表达分析

Genome-Wide Identifi cation and Expression Analysis of Auxin Response Factor(ARF)Gene Family in Apple

生长素响应因子（auxinresponsefactor,ARt）基因在调控生长素响应基因和生长素信号转导途径以及其它多个生长发育过程具有重要作用。本研究利用BlastP程序比对并获得苹果ARF基因家族，通过DNAMAN6．0、MEGA5．0、WebLogo3、Maplnspect和MEME软件对苹果4尺，基因进行分析，采用RT-PCR技术研究基因组织表达情况。结果表明，苹果基因组存在29个爿灯基因，进化上可分为Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组，每组成员数目分别是4、5、10、6和4个。内含子和外显子结构分析表明，该基因家族由2-15个外显子构成。染色体分布结果显示，MdA腿因在染色体上分布不均匀。分别鉴定出4对和2对朋幽腿因经历了串联复制和片段复制，14个MdARF基因经历了全基因组复制。保守元件分析表明，苹果4腿因家族DBD区域、ARF区域、Ⅲ元件和Ⅳ元件结构高度保守。半定量结果表明，大多数MaaRF基因在根、茎、叶、花和果中均有表达。

Auxin response factor （ARF） genes play multiple important roles in the regulation of auxin response genes, auxin signal transduction pathway and other processes. In this study, ARF genes from apple （Malus domestica Borkh） genome were obtained via BlastP analysis, and their amino acid sequences were analyzed with DNAMAN 6.0, MEGA 5.0, WebLogo 3, MapInspect and MEME software, their expression patterns in different tissues were checked by RT-PCR analysis. The results showed that 29 MdARF candidate genes were existed in apple genome. The results of phylogenetic analysis revealed that MdARF gene family was divid- ed into five classes： Class I （four members）, Class Ⅱ （five members）, Class III （ten members）, Class Ⅳ （six members） and Class V （four members）, respectively. The results of intron-exon structure analysis indicated that MdARF gene family members were composed of 2-15 exons. Chromosome mapping analysis revealed that MdARF genes were distributed unevenly on 15 chromosomes. Four pairs and two pairs had undergone tandem duplication and segment duplication, respectively. Conserved motif analysis showed that the DNA-binding domain, ARF domain, motif Ⅲ and motif Ⅳ of MdARF gene family were highly conserved. Semi RT-PCR results indicated that most of MdARF genes were expressed in roots, stems, leaves, flowers and fruits.