西番莲查尔酮合成酶(CHS)基因家族全基因组鉴定及表达模式

Genome-wide identification and expression analysis of the CHS gene family in passion fruit

为了解西番莲(Passiflora edulis Sims f.)查尔酮合成酶(chalcone synthase,CHS)基因家族的分子进化特性及其在果皮着色与非生物胁迫中的功能,从Pfam数据库下载CHS蛋白HMM模型,并使用HUMMER 3.0、Blast工具和CDD-search鉴定出西番莲基因组中的CHS基因.采用TBtools、EXPASy、MEGA 7.0、MEME、PRAB、SWISSMODEL和PlantCARE等软件对其氨基酸与碱基序列进行生物信息学分析,采用qRT-PCR的方法检测西番莲CHS(PeCHS)基因家族成员进行表达模式分析.研究结果显示西番莲基因组中共有11个PeCHS基因家族成员,分布在6条染色体上,可分为4个亚族,基因结构分析显示2个PeCHS(PeCHS5和PeCHS9)基因具有3个外显子,其他PeCHS基因只具有2个外显子.西番莲物种内共线性分析结果显示两个PeCHS基因对具有片段重复特征:PeCHS3-PeCHS6和PeCHS7-PeCHS9.多物种共线性分析结果显示,只有PeCHS10基因与其他物种具有进化关系.启动子顺式作用元件分析表明该基因家族成员启动子上含有大量逆境胁迫和激素、响应元件.qRT-PCR结果显示PeCHS基因在紫色果皮中的表达量明显高于黄色果皮,且大部分PeCHS基因的表达量在紫色西番莲果皮转色后显著增加.此外,分别有5个(PeCHS3、PeCHS4、PeCHS6、PeCHS8、PeCHS10)和6个(PeCHS1、PeCHS3、PeCHS4、PeCHS7、PeCHS8、Pe CHS11)基因的表达量在高温与低温胁迫下显著提高.本研究表明西番莲的CHS家族成员序列相对保守,并且部分成员可能在果皮花青素积累与温度胁迫中发挥重要作用.(图10表4参53)

This study aimed to investigate the molecular evolution of the chalcone synthase(CHS) gene family in passion fruit(Passiflora edulis Sims) and their expression patterns during pericarp coloring and abiotic stress. We downloaded the HMM model of CHS protein from the Pfam database, and the CHS gene was identified by HUMMER 3.0, BLAST tool, and CDD-Search. TBtools EXPASy, MEGA 7.0, MEME, PRAB, SWISS-MODEL, and PlantCARE were used for bioinformatic analysis of amino acids and base sequences. The expression patterns of CHS(Pe CHS)gene family members were analyzed by qRT-PCR. The results showed that a total of 11 CHS gene members were identified. They were dispersed in six chromosomes and divided into four subfamilies according to phylogenetic analysis. Exon/intron structure analysis showed that all Pe CHS genes had two exons, except for two genes(Pe CHS5and PeCHS9) that had three exons. Two gene pairs(PeCHS3–PeCHS6 and PeCHS7–PeCHS9) were found to have fragment duplication as identified by intraspecific collinearity analysis, and only Pe CHS10 was found to have an evolutionary relationship with other species as identified by interspecies collinearity analysis. Of the 11 Pe CHS genes, many plant hormones and abiotic and biotic stress responsive elements exist in their promoter regions. The q RT-PCR results showed that the expression level of the Pe CHS gene in purple pericarps was significantly higher than that in yellow pericarps, and the expression levels of most PeCHS gene families were significantly increased after the pericarp turned purple in purple passion fruits. Furthermore, five(Pe CHS3, Pe CHS4, Pe CHS6, Pe CHS8,and PeCHS10) and six gene pairs(PeCHS1, PeCHS3, PeCHS4, PeCHS7, PeCHS8, and PeCHS11) showed significantly higher expression levels under high and low temperature stress, respectively. This study showed that the sequence of the Pe CHS family is relatively conserved, and that some members might play an important role in anthocyanin accumulation in the pericarp, as well as in response to temperature stress.