苹果MdCyb5家族全基因组鉴定及表达分析

Genome-wide Identification and Expression Analysis of MdCyb5 Family in Apple

细胞色素b5(cytochromeb5,Cyb5)在植物的种子萌发、生长发育、抗逆性以及乙烯信号转导中起着重要作用。为揭示苹果Cyb5基因的功能,本研究对苹果Cyb5基因家族(MdCyb5)进行全基因组鉴定,并研究它们在苹果不同组织中(根,茎,叶,花,果实和种子)的表达模式。利用生物信息学手段,分析家族成员基因结构、转录因子结合位点(transcription factor binding sites,TFBS)、启动子顺式作用元件分布情况及染色体定位。同时对该基因家族成员编码蛋白质的理化性质、保守基序、系统进化关系进行分析。基于NCBI中苹果不同组织转录组数据,分析MdCyb5家族成员的表达情况。结果显示:(1)MdCyb5家族共有9个成员,编码区介于402~411 bp,在第0、1、4、5、7、10和16号染色体均有分布。(2)大部分MdCyb5基因包含3个外显子,所有成员均无信号肽且定位在内质网中。(3)系统进化树分析发现,MdCyb5可分为Class I和Class II两类,且Class II又可细分为5个小组,其中含MdCyb5-2和Md Cyb5-6的小组为苹果特有。(4)顺式作用元件和TFBS预测结果显示,MdCyb5成员存在多种植物激素相关和光响应元件以及大量的AP2/ERF结合位点。(5)NCBI的GEO中苹果不同组织转录组数据分析结果显示,Md Cyb5s在叶、花、果实中的表达水平高于种子、茎和根中的表达。该家族的9个成员结构比较相似,在苹果生命活动及乙烯信号转导过程中发挥重要作用。

Cytochrome b5(Cyb5)plays an important role in regulating plant seed germination,stress resistance and ethylene signal transduction.In order to reveal the function of apple Cyb5 genes,we identified the members of Cyb5 gene family(MdCyb5)of apple and studied their expression patterns in different apple tissues(root,stem,leaf,flower,fruit and seed).Using bioinformatics analyses identified the gene structures,transcription factor binding sites(TFBS),promoter cis-acting elements and chromosome location of family members.Furthermore,we analyzed the expression patterns of MdCyb5 family members in different apple tissues by using transcriptomic data downloaded from NCBI.Our results show that:(1)There are 9 members of MdCyb5 family(MdCyb5-1~MdCyb5-9),with the coding region ranging from 402 to 411 bp and distributed on chromosomes 0,1,4,5,7,10 and 16.(2)Most of the MdCyb5 genes contain three exons.All of them has no signal peptide and located in the endoplasmic reticulum.(3)Phylogenetic tree analysis found that MdCyb5 can be divided into Class Ⅰ and Class Ⅱ.The Class Ⅱ can be subdivided into five groups.Furthermore,there is a group which contains MdCyb5-2 and MdCyb5-6 is apple-specific among the Class Ⅱ.(4)Cis-acting elements and TFBS predicted results showed that MdCyb5 members had a variety of plant hormone-related and light-responsive elements as well as a large number of AP2/ERF binding sites.(5)Results from transcriptomic data analysis of different apple tissues showed that expression levels of MdCyb5s were higher in leaves,flowers and fruits than in seeds,stems and roots.The 9 members of this family are similar in structure and may play an important role in ethylene signal transduction.