蒙古冰草MYB转录因子基因的序列分析

Sequence Analysis of MYB Transcription Factor Genes in Agropyron mongolicum

MYB转录因子是一类与植物抗逆相关的蛋白家族,通过激活植物抗逆应答基因的表达而提高其抗逆性。为挖掘蒙古冰草(Agropyron mongolicum)抗旱相关的MYB基因,本研究在已有转录组测序数据的基础上,用Plant TFDB数据库中的Prediction和Blast对MYB基因筛选及保守结构域分析,通过生物学方法对筛选出的MYB转录因子进行分析,预测其分子量和等电点等理化性质、基序、二级结构和三级结构;并用MEGA 7.0.21与已报道具有抗旱功能的29个MYB蛋白进行多序列比对分析并构建系统进化树。结果表明:蒙古冰草中筛选出9个MYB基因,蛋白大小在113~576 aa,分子量和等电点分别介于12.83~61.52 kD和4.68~9.80 kD之间,都为不稳定的亲水性蛋白;基序预测得到2个特征基序,最长的基序含50个氨基酸;α-螺旋和无规则卷曲是主要的二级结构,三级结构中都含有螺旋-转角-螺旋结构;进化树分析中,38个基因很好的聚为两类,其中Unigene 25843、Unigene 42380、Unigene 52355、Unigene 54016分别于AtMYB33、AtMYB61、Os MYB48-1、AtMYB20在同一分支上,高度同源,推测从蒙古冰草中筛选得到的MYB基因参与干旱胁迫应答,该研究为下一步蒙古冰草MYB基因功能的研究提供帮助。

MYB transcription factors are a family of proteins related to plant stress resistance, which can enhance their resistance by activating the expression of plant reverse stress response genes. In order to exploit drought resistance MYB gene of Agropyron mongolicum, MYB genes and conservative domains were screened and analyzed with prediction and blast software in plant TFDB database based on the the previous transcriptome sequencing researches. The selected MYB transcription factors were analyzed by biological methods, and predicted the molecular weight, isoelectric point, and other physicochemical properties, motif, secondary and tertiary structure, and multiple alignments analysis and phylogenetic tree construction were performed with 29 MYB transcription factor sequences that function of drought resistance have been reported by MEGA 7.0.21. The main results are as follows: 9 MYB genes were selected from A. mongolicum, and the molecular size were ranged from 113 aa to 576 aa, and the molecular weight and isoelectric point were respectively in 12.83~61.52 and 4.68~9.80 k D, are all unstable hydrophilic protein.Two characteristics motif of MYB transcription factor genes in A. mongolicum were predicted, and the longest motif contains 50 amino acids;The alpha helix and the irregular curl are the primary secondary structure. Tertiary structure all contain Helix-Turn-Helix;In phylogenetic tree analysis, 38 genes well grouped into two categories. Among them, Unigene 25843, Unigene 42380, Unigene 52355, Unigene 54016 with AtMYB33, AtMYB61, Os MYB48-1,AtMYB20 in the same branch, highly homologous, and speculated that it may be play a pivotal role in drought stress responses processes. The study provides a foundation for function of MYB genes in A. mongolicum.