龙眼GH3家族成员的全基因组鉴定及表达分析

Genome-wide identification and expression analysis of GH3 gene family in Dimocarpus longan

为探究龙眼GH3基因家族结构特征及表达模式,基于龙眼基因组及转录组数据库对DlGH3基因家族进行鉴定.共鉴定出10个DlGH3家族成员,分为3个亚家族(Ⅰ、Ⅱ、Ⅲ),均含有GH3保守结构域.启动子序列预测显示,DlGH3含多个与激素响应、光响应、胁迫响应及生长发育相关的顺式作用元件.转录组数据和qRT-PCR的表达谱分析显示,DlGH3在体胚发生早期的表达模式存在差异,DlGH3.5在胚性愈伤组织中的表达量极高,DlGH3.3和DlGH3.6在花、花芽和根中特异性表达;DlGH3不同成员在蓝光、白光和黑暗处理下的表达趋势存在差异.此外,在外源IAA、2,4-D、MeJA、GA3、ABA和SA处理下,DlGH3成员的表达均被不同程度诱导.因此,DlGH3在进化中具有较高的保守性,可能参与调控龙眼体胚发生、外源激素响应、龙眼开花和根的生长等发育过程.

To explore the structural characteristics and expression pattern of GH3 gene family in Dimocarpus longan Lour., the DlGH3 gene family in longan was identified based on the genomic and transcriptomic data. Ten DlGH3 members were identified and divided into 3 subfamilies, and all of them contained GH3 conservative domain. Multiple cis-regulatory elements were found in the promoter of DlGH3 gene family, involving in hormone response, light response, stress response and growth. Transcriptome and qRT-PCR analysis showed different expression pattern of DlGH3 during early somatic embryogenesis stage. DlGH3.5 was highest expressed in embryogenesis callus, while DlGH3.3 and DlGH3.6 were specifically expressed in flowers, flower buds and roots. The expression trends of different DlGH3 members were different under blue light, white light and dark. In addition, the expressions of DlGH3s were also induced by exogenous IAA, 2,4-D, MeJA, GA3, ABA and SA. In conclusion, DlGH3 are highly conservative in evolution and involved in the regulations of somatic embryogenesis, flowering and root, and responses of exogenous hormones.