石斛JmjC基因家族的鉴定及响应不同光周期的表达分析

Genome-wide Identification and Expression Analysis of JmjC Gene Family in Response to Different Photoperiods in Dendrobium

利用生物信息学方法对石斛组蛋白去甲基化关键酶基因JmjC进行全基因组鉴定,通过qRT-PCR检测DoJMJ组织表达模式及对不同光周期的响应。结果表明,在铁皮石斛(Dendrobium officinale)基因组上共鉴定到17个JmjC,保守结构域分析结果显示,该家族蛋白划分为5个亚家族(JARID1、JHDM3、JHDM2、JMJD6和JmjC-only),各亚家族所含保守结构域数量不等;基因结构分析发现,各亚家族的外显子和内含子数量有所差异,同一亚家族具有相似的外显子/内含子结构;启动子顺式作用元件分析发现DoJMJ家族成员启动子区域有诸多Auxin、ABA、GA、MeJA、SA等激素响应元件及光、干旱、低温、防御和胁迫等环境信号响应元件;qRT-PCR数据表明,金钗石斛(Dendrobiumnobile)中该家族10个成员在茎和叶片中表达量较高,少数成员在根中的表达较高,所有成员在果实中表达均较低,推测Do JMJ主要在茎和叶片发育过程发挥作用;此外,该家族成员在不同光周期下呈现不同的表达模式,11个成员在12 h(光照)/12 h(黑暗)下表达量较高,少数成员在4 h/20 h、8 h/16 h、24 h/0 h光周期下高表达。

Bioinformatics methods were used to perform the genome-wide identification of Dendrobium JmjC gene. The expression patterns of DoJMJ in different tissues and their responses to various photoperiods were detected by qRT-PCR. Seventeen JmjC gene family members were identified in the Dendrobium officinale genomic database,and they were divided into five subfamilies(JARID1,JHDM3,JHDM2,JMJD6 and JmjC-only)based on the conserved domains. The number of conservative domains in each subfamily varies;the gene structures analysis showed that the numbers of exons and introns in different subfamilies were different. There were similar exon/intron structures within the same subfamilies. Promoter cis-acting elements analysis revealed that DoJMJ family members contained hormone response elements such as Auxin,ABA,GA,MeJA,SA elements,and environmental signaling response elements including light,drought,low temperature,defense and stress elements,qRT-PCR results showed that the expression of ten members were higher in stem and leaf,a few members showed higher expression levels in root,and all members had lower expression in the fruit of the Dendrobium nobile,which speculated that DoJMJ might play a major role in the developmental processes of stem and leaf. In addition,the family members also exhibited different expression patterns in various photoperiod conditions. Eleven members were highly expressed a 12 h/12 h(light/dark)cycle,and a few members showed higher expression levels in 4 h/20 h,8 h/16 h and 24 h/0 h(L/D)light cycles.