紫鸭跖草热激转录因子基因家族鉴定及在Cu2+胁迫下表达模式分析

Identification of heat stress transcription factors gene family in Setcreasea purpurea and analysis of its expression pattern under Cu2+ stress

摘要:

热激转录因子(Hsf) 是植物中最重要的转录因子家族之一，在植物遭遇热、干旱和重金属等多种非生物胁迫中具有重要的作用。为明确紫鸭跖草Hsf基因家族的结构及功能，从紫鸭跖草全长转录组数据库筛选鉴定出20个SpbHsf基因，并运用生物信息学工具和qRT-PCR进行分析。结果显示：SpbHsf蛋白均为亲水性蛋白，定位于细胞核的SpbHsf蛋白有12个，所有SpbHsf蛋白二级结构的α螺旋和无规卷曲的含量较高。SpbHsf基因分为3个亚族，各亚族都包含独特的保守基序。全部SpbHsf蛋白含有DBD和HR-A/B结构域。系统进化分析显示，与SpbHsf蛋白同源性最高的是水稻OsHsf蛋白。20个SpbHsf基因在紫鸭跖草根组织中均有表达。相比于对照组，根组织在Cu²⁺胁迫下，8个SpbHsf基因的表达量显著上调，8个SpbHsf基因的表达量显著下调。研究结果为紫鸭跖草Hsf基因家族的功能验证及表达模式提供了一定的理论参考。

Abstract:

Heat stress transcription factors (Hsf) family is one of the most important transcription factor families in plants, and plays an important role in the growth and development of plants when encountering abiotic stresses such as heat, drought, and heavy metals. In this study, 20 SpbHsf genes were identified from the full-length transcriptome database of Setcreasea purpurea, and the structure and function of the Hsf gene family were analyzed using bioinformatics tools and qRT-PCR. The results showed that all SpbHsf proteins were hydrophilic. There were 12 SpbHsf proteins located in the nucleus, and the content of α-helix and random coil in the secondary structure of all SpbHsf proteins was high. The SpbHsf genes are divided into three subfamilies, each of which contains unique conserved motifs. All SpbHsf proteins contain DBD and HR-A/B domains. Phylogenetic analysis showed that OsHsf in Oryza sativa protein had the highest homology with SpbHsf protein. All the 20 SpbHsf genes were expressed in the root tissues of S. purpurea. Among them, 8 were significantly up-regulated while 8 were significantly down-regulated under Cu²⁺ stress. This study may help better understand the function and expression pattern of the S. purpurea Hsf gene family.