小黑杨HD-Zip转录因子家族生物信息学及应答盐胁迫分析

Bioinformatics and Response to Salt Stress Analysis of the HD-Zip Transcription Factor Family in Populus simonii × P. nigra

HD-Zip转录因子基因是植物中特有的一类蛋白家族,在植物生长发育和逆境应答胁迫过程中发挥重要作用。HD-Zip转录因子基因是由高度保守的同源异型结构域(HD)和亮氨酸拉链域(LZ)结构域构成的特殊结构模型。杨树HD-Zip转录因子家族共有63个基因,可被分为HD-ZipⅠ、HD-ZipⅡ、HD-ZipⅢ和HD-ZipⅣ四个亚家族。本文利用RNA-Seq分析了盐胁迫条件下HD-Zip基因家族在小黑杨根、茎、叶等不同组织的基因表达差异,从转录组水平揭示其应答胁迫环境的分子机制,结果表明,盐胁迫下在叶中有25个HD-Zip基因下调表达,21个基因上调表达;茎中有42个基因下调表达,11个基因上调表达;根中有26个基因下调表达,24个基因上调表达。另外,本文根据拟南芥HD-Zip转录因子家族基因的已知功能,预测了杨树HD-Zip转录因子同源基因的功能,并利用生物信息学方法分析了杨树HD-Zip转录因子蛋白序列的保守结构域、氨基酸组成和理化性质等,为进一步研究杨树HD-Zip转录因子基因功能提供参考。

The HD-Zip transcription factor family is a kind of special protein in plant,playing crucial roles in plant development processes and abiotic stresses response. The protein family includes a highly conserved homeodomain（ HD） and a leucine zipper domain（ LZ）,forming a special structural model. The HD-Zip transcription factor family,including 63 members,can be classified into 4 subfamilies HD-Zip Ⅰ,HD-Zip Ⅱ,HD-Zip Ⅲ and HD-Zip Ⅳ. RNA-Seq analysis of poplar roots,stems and leaves under salt stress was conducted for the differentially expressed genes in different tissues,and reveal the molecular mechanism of the response to stress environment. Therewere 25 HD-Zip genes down-regulated and 21 HD-Zip genes up-regulated in leaves under salt treatment,42 genes down-regulated and 11 genes up-regulated in stems,and 26 genes downregulated and 24 genes up-regulated in roots. According to gene annotations in Arabidopsis thaliana,the functions of HD-Zip transcription factor in poplarwere predicted. The conserved domains, structural characteristics and chemical properties of HD-Zip family members were also studied by bioinformatics,providing reference for gene functions of HD-Zip family in poplar.