油棕C2H2基因家族鉴定及低温胁迫下的表达分析

Identification and Expression Analysis of the C2H2 Gene Family in Oil Palm under Low Temperature Stress

C2H2型锌指蛋白是最常见的锌指蛋白之一,广泛存在于真核生物中,在植物的生长发育、盐、低温、干旱胁迫等非生物胁迫响应中扮演重要作用。本研究以拟南芥C2H2氨基酸序列作为探针,在油棕基因组数据库中进行本地BLASTP比对和保守结构域预测分析,筛选出油棕C2H2型锌指蛋白家族成员,利用生物信息学手段对基因家族成员的理化性质、进化关系、染色体位置、基因结构、保守基序和启动子顺式元件进行分析,并利用转录组数据和荧光定量PCR方法分析EgC2H2基因家族成员在低温胁迫下的表达情况。结果显示:从油棕基因组中共鉴定出73个C2H2型锌指蛋白家族成员,EgC2H2家族成员氨基酸的数目为128~556个,分子量为14176.73~58983.30 Da,等电点为4.99~9.62,不稳定系数为38.84~86.01,亲水性为–1.154~-0.226,亚细胞定位显示C2H2基因家族所有成员均定位于细胞核;系统进化树分析显示EgC2H2家族成员可以分为4个亚家族,EgC2H2家族成员多数归类于第Ⅰ亚家族和第Ⅱ亚家族,且同一亚家族成员的结构域具有较高的一致性;染色体定位结果显示,EgC2H2家族成员不均匀地分布于油棕的16条染色体上;启动子顺式元件分析显示,EgC2H2家族包含许多光响应元件、植物激素响应元件和逆境胁迫响应元件;转录组数据分析显示,大部分EgC2H2基因响应低温胁迫,且大多数EgC2H2基因在耐寒材料中高表达,在冷敏感材料中低表达;荧光定量PCR分析显示,EgC2H2-23、EgC2H2-11、EgC2H2-19、EgC2H2-17和EgC2H2-21显著上调表达,且在耐寒材料中的表达量显著高于冷敏感材料,推测这些基因可能在油棕低温响应中发挥关键作用,可以作为候选基因进一步深入研究。本研究为深入研究油棕C2H2基因家族功能提供理论参考。

C2H2 zinc finger protein is one of the most common zinc finger proteins and widely found in eukaryotes.It plays an important role in plant growth and development,abiotic stress response to salt,low temperature and drought stress.In this study,the C2H2 amino acid sequence of Arabidopsis thaliana were used to blast with local BLASTP in the oil palm genome database and to predict the conservative domains,and to screen the C2H2 zinc finger protein fam-ily of oil palm.The physical and chemical properties,evolutionary relationships,chromosomal location,gene structure,conservative motif and promoter cis-elements were analyzed through bioinformatics softwares,the expression of EgC2H2 gene was analyzed by the transcriptome data and real-time fluorescence quantitative PCR under low tempera-ture stress.A total of 73 C2H2 type zinc finger protein family members were identified from the genome of oil palm.The number of amino acids in EgC2H2 family was between 128 and 556,The molecular weight was between 14176.73 and 58983.30 Da,the isoelectric point was between 4.99 and 9.62,the instability index was between 38.84 and 86.01,and the gravy was between-1.154 and-0.226.Subcellular localization showed that the C2H2 gene family were local-ized in the nucleus.Phylogenetic tree analysis showed that EgC2H2 family members were divided into four subfamilies,most members of EgC2H2 family were classified into subfamilyⅠand subfamilyⅡ,and the domains of the same subfamily members were highly consistent.Chromosome location results showed that EgC2H2 family members were unevenly distributed on the 16 chromosomes of oil palm.Analysis of promoter cis-elements showed that the EgC2H2 family contained many promoter cis-elements related to light response elements,plant hormones response elements and stress response elements.Transcriptome analysis showed that most EgC2H2 genes responded to low temperature stress,and most EgC2H2 genes were highly expressed in cold-tolerant materials and low expressed in cold-sensitive materials.qRT-PCR analysis showed that the expression level of EgC2H2-23,EgC2H2-11,EgC2H2-19,EgC2H2-17 and EgC2H2-21 was significantly up-regulated,and the expression level of cold-tolerant materials was significantly higher than that of cold-sensitive materials.It was speculated that the genes would play a key role in oil palm response to low temperature stress,and can be used as candidate genes for further study.This study would provide theoretical reference for further study on the functional analysis of C2H2 gene family in oil palm.