基于转录组测序的红树莓bHLH转录因子家族鉴定及分析

Identification and analysis of bHLH transcription factor family in red raspberry based on transcriptome sequencing

关键词:  红树莓, 转录组测序, bHLH转录因子, 基因家族, 树莓酮

Key words:  red raspberry(Rubus idaeus), transcriptome sequencing, bHLH transcription factors, gene family, raspberry ketone

摘要:

bHLH转录因子是植物中数量较大的一类转录因子家族,在植物的生长发育、次级代谢调控、激素响应等方面发挥着重要作用。红树莓果实中含有丰富的树莓酮,为了深入探究bHLH转录因子在红树莓生长发育及树莓酮合成过程中的作用,该研究基于‘波尔卡'和‘橙色传奇'2种红树莓果实的转录组测序,鉴定了红树莓bHLH基因家族成员,并对这些基因进行生物信息学分析。结果表明:(1)红树莓果实中共鉴定到95个bHLH转录因子家族成员。(2)红树莓的bHLH转录因子家族成员多数为不稳定蛋白; 超过半数成员定位于细胞核。(3)bHLH转录因子N端包含保守的His5-Glu9-Arg13序列,C端包含保守的Leu序列。(4)系统发育树将该家族成员分为20个亚家族,其中R亚家族成员最多,有12个。(5)表达模式图表明bHLH转录因子在青果期表达量较高,成熟期表达量较低。该研究结果为筛选与树莓酮含量变化一致的bHLH转录因子提供了依据,为进一步探究红树莓bHLH家族的功能提供了参考。

Abstract:

bHLH transcription factors are a large family of transcription factors in plants, which play important roles in plant growth and development, secondary metabolism regulation, and hormone response. Red raspberry fruit is rich in raspberry ketone. To investigate the role of bHLH transcription factor in the growth and development of red raspberry and the synthesis of raspberry ketone, members of the red raspberry bHLH gene family were identified and bioinformatics analysis of these genes were performed based on transcriptome sequencing of two red raspberry fruits, ‘Polka' and ‘Orange Legend'. The results were as follows:(1)A total of 95 bHLH transcription factor family members were identified in red raspberry fruits.(2)Most of the bHLH transcription factor family members were unstable hydrophobic proteins; and more than half of them were localized in the nucleus.(3)bHLH transcription factor N-terminal contained the conserved His5-Glu9-Arg13 sequence and C-terminal contained the conserved Leu sequence.(4)The phylogenetic tree divided the family members into 20 subfamilies, of which the R subfamily had the most members with 12.(5)The expression pattern map indicated that the bHLH transcription factor was expressed at a higher level during the green fruit stage and at a lower level during the ripening stage. The results provide a basis for screening bHLH transcription factors that are consistent with changes in raspberry ketone content and provide a reference for further exploring the function of red raspberry bHLH family.