银杏MYB转录因子的鉴定及特征分析

Identification and characterization of MYB transcription factors in Ginkgo biloba

[目的]MYB蛋白是真核生物中一类重要的转录因子,在植物形态建成、生长发育、初生和次级代谢产物合成等生命过程中起重要调控作用。银杏作为植物中的"活化石",其提取物中含有的活性成分次生代谢物类黄酮等对人体有益。在类黄酮的生物合成中,MYB转录因子扮演着重要角色。本研究从转录组水平详细鉴定和分析了银杏GbMYB转录因子,为今后GbMYB的功能研究奠定基础,也为其他物种MYB转录因子的分析提供方法。[方法]本文首先利用BlASTp和PlantTFbcat等生物信息学工具对银杏的MYB蛋白序列进行筛选和鉴定;其次运用MEME和MEGA 7.0软件分别对GbMYB蛋白进行基序和系统进化分析;最后使用MeV对GbMYB在银杏各组织中的表达水平进行聚类分析。[结果]从41151个银杏蛋白中共鉴定出60个MYB转录因子,根据MYB保守域的特点将其分为R1-MYB、R2R3-MYB和R1R2R3-MYB三大类。系统进化树分析发现60个GbMYB可分为16个亚家族且具有相似功能的蛋白序列通常聚在一个家族。在银杏GbMYB蛋白中共检测到21种不同的保守基序。表达谱数据分析表明,一些GbMYB基因的表达具有组织特异性。[结论]本研究利用生物信息学方法,在银杏转录组水平上共鉴定出参与调控银杏各个组织发育的60个GbMYB转录因子;结合拟南芥AtMYB家族分类法将GbMYB分为16个亚家族;保守基序分析显示GbMYB在功能上具有多样性。研究结果为全面解析银杏MYB基因结构与生物学功能提供了新信息,也为进一步研究银杏GbMYB转录因子在次生代谢产物中的调控功能奠定了基础。

[Objective] MYB is one of the largest families of transcription factors in plants and participates in kinds of bi- ological processes, such as, plant development, cell morphogenesis and the synthesis of primary and secondary metabo-lites. Ginkgo biloba is called ＂living fossil＂ in plant and contains many secondary metabolites,such as flavonoid. MYB transcription factors play an important role in flavonoid biosynthesis. In this study, MYB transcription factor of ginkgo were identified at the transcriptome level. The result will lay the foundation for functional study of GbMYB and identi- fication of MYB from other species. [Methods] Firstly, MYB transcription factors in ginkgo were screened and identi-fied by BIASTP and PlantTFbcat. Sencondly, MEME and MEGA 7.0 software were used to analyze motifs and evolu- tion of ginkgo MYB, respectively. Lastly, the expression patterns of GbMYB in different tissues of ginkgo were analyzed by using MeV software. [Result] In our study, a total of 60 GbMYB were identified from 41151 proteins in ginkgo and classified into three distinct groups （R1-MYB, R2R3-MYB and R1R2R3-MYB） according to the structure of MYB domain. Phylogenetic analysis showed these MYB genes were classified into 16 subgroups. Clearly, GbMYBs with the similar functions were gathered together. There were 21 different conserved motifs in GbMYB. Expression profiles analysis showed that the expression of GbMYB had tissue specificity. [Conclusion] Our study identified 60 Gb- MYB at the transcriptome level, which participate in the development of different tissues. The GbMYB was classed into 16 subfamilies by referring to AtMYB. The result of conserved motif analysis showed that GbMYB have diverse functions. Our research provided new message for comprehensively analyzing the structure and function of GbMYB and laid the foundation for the further study of GbMYB in the regulating of secondary metabolites.