甜瓜HD-Zip家族基因的鉴定及在表皮毛发育中的表达分析

Identification of HD-Zip family genes in melon and expression analysis in trichome development

【目的】研究HD-Zip家族基因在甜瓜表皮毛发育过程中的表达模式和功能。【方法】利用生物信息学方法对甜瓜HD-Zip家族基因进行全基因组鉴定、染色体定位、系统进化分析、基因结构分析、理化性质分析、保守序列分析、顺式作用元件预测、共线性分析、蛋白互作网络预测和调控该家族基因的MicroRNA预测,并结合甜瓜不同组织部位和不同表皮毛材料的转录组分析及qRT-PCR验证,筛选与甜瓜表皮毛发育相关的基因。【结果】甜瓜基因组编码37个HD-Zip家族成员,不均等地分布在9条染色体上。该家族成员分为4个亚家族,各亚家族成员具有相似的基因结构和保守基序。共线性分析显示,甜瓜HD-Zip家族基因的形成存在着连锁遗传且伴随串联复制、片段复制等染色体复制事件的发生,其基因组进化过程与黄瓜高度相似。顺式元件分析显示,该家族成员含有与表皮毛发育相关的赤霉素、茉莉酸、脱落酸和水杨酸响应元件。调控HD-Zip家族基因的MicroRNA主要有miRNA166、miRNA17和miRNA395家族。不同表皮毛甜瓜材料的转录组分析显示,该家族中CmHDZ1、CmHDZ3、CmHDZ14、CmHDZ17和CmHDZ36基因在无表皮毛材料中表达显著下调,CmHDZ21、CmHDZ23和CmHDZ28基因表达显著上调。进一步在不同表皮毛材料的子房和叶片中的表达模式分析显示,与有表皮毛材料相比,CmHDZ5、CmHDZ14、CmHDZ17基因在无表皮毛材料中表达显著下调,CmHDZ22基因表达显著上调。【结论】甜瓜中编码37个HD-Zip家族基因,基于其在甜瓜不同组织部位和不同表皮毛材料中的表达模式分析,筛选到9个与甜瓜表皮毛发育密切相关的CmHDZs基因,其中CmHDZ1、CmHDZ14、CmHDZ17基因在无表皮毛甜瓜中的表达显著下调,可能参与赤霉素和茉莉酸途径介导的甜瓜表皮毛发育的正调控,CmHDZ22基因在无表皮毛甜瓜中表达显著上调,可能负调控表皮毛的发育。

【Objective】The purpose of this study was to analyze the expression pattern and function of the HD-Zip familygenes,so as to understand the roles of HD-Zip family genes during trichome development in melon(Cucumis melo L.).【Method】 The genome-wide identification,chromosomal localization analysis,phylogenetic tree analysis,gene structure analysis,physicochemical property analysis,conserved sequence analysis,cis-acting element prediction,gene collinearity analysis,protein interaction network prediction and microRNA prediction of HD-Zip family genes were performed using bioinformatics methods,and the transcriptome analysis and qRT-PCR verification of different tissue and different trichome materials of melon were combined to screen genes associated with trichome development.【Result】In this study,the melon genome encoded 37 members of the HD-Zip family,The HD-Zip family members were unevenly distributed on nine chromosomes.The HD-Zip family members were divided into 4 subfamilies,and the same subfamily members had the similar genetic structures and conserved motifs.The collinear analysis showed that the formation of melon HD-Zip family genes had linkage inheritance and accompanied with the occurrence of chromosomal duplication modes such as tandem replication and fragment replication,and its genome-wide evolution process was highly similar to that of cucumber.The cis-elements results indicated that the CmHDZ members contained a large number of gibberellins,jasmonic acids,abscisic acids,and salicylic acids response elements associated with trichome development.The microRNA families that regulated HD-Zip family genes mainly included miRNA166,miRNA17 and miRNA395 families.The transcriptome analysis of different melon trichome materials showed that the gene expression of CmHDZ1,CmHDZ3,CmHDZ14,CmHDZ17 and CmHDZ36 were significantly downregulated in the without trichome materials group,and thegene expression of CmHDZ21,CmHDZ23 and CmHDZ28 were significantly upregulated.The further analysis of expression pattern for candidate genes in the ovary and leaves of different trichome materials showed that,compared with the trichome material treatment,the gene expression of CmHDZ5,CmHDZ14 and CmHDZ17 was significantly downregulated and the gene expression of CmHDZ22 was significantly upregulated in the without trichome material treatment.【Conclusion】Melon encoded 37 HD-Zip family members,and nine CmHDZs genes closely associated with trichome development were screened according to their expression patterns in different tissue and different trichome materials of melon.Among them,the gene expression of CmHDZ1,CmHDZ14 and CmHDZ17 were significantly downregulated in melon without trichome materials,which may be participated in the positive regulation of trichome development mediated by gibberellin and jasmonic acid pathways.The gene expression of CmHDZ22 was significantly upregulated,maybe due to the negatively regulation trichome development.