中国农业科学 ›› 2021, Vol. 54 ›› Issue (17): 3573-3586.doi: 10.3864/j.issn.0578-1752.2021.17.002

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

苦荞WOX家族全基因组鉴定及响应愈伤诱导率表达分析

侯思宇1(),王欣芳1,杜伟1,冯晋华1,韩渊怀1,李红英1,刘龙龙2,孙朝霞1()   

  1. 1山西农业大学农学院,山西太谷 030801
    2山西农业大学农业基因资源研究中心,太原 030031
  • 收稿日期:2021-02-18 接受日期:2021-05-08 出版日期:2021-09-01 发布日期:2021-09-09
  • 通讯作者: 孙朝霞
  • 作者简介:侯思宇,Tel:18635068055;E-mail: bragren123@163.com
  • 基金资助:
    国家重点研发计划中欧政府间合作项目(2017YFE0117600);国家自然科学基金(32070365);山西省农业科学院应用基础研究计划(YGC2019FZ2);财政部和农业农村部:国家现代农业产业技术体系(CARS-07-A-2)

Genome-Wide Identification of WOX Family and Expression Analysis of Callus Induction Rate in Tartary Buckwheat

HOU SiYu1(),WANG XinFang1,DU Wei1,FENG JinHua1,HAN YuanHuai1,LI HongYing1,LIU LongLong2,SUN ZhaoXia1()   

  1. 1College of Agronomy, Shanxi Agricultural University, Taigu 030801, Shanxi
    2Center for Agricultural Genetic Resources Research, Shanxi Agricultural University, Taiyuan 030031
  • Received:2021-02-18 Accepted:2021-05-08 Online:2021-09-01 Published:2021-09-09
  • Contact: ZhaoXia SUN

摘要:

【目的】全基因组鉴定苦荞WOX(WUSCHEL-related homeobox)基因,揭示其基因家族成员序列特征、基因表达模式及与出愈率的相关性,为突破苦荞再生及遗传转化难题提供理论基础。【方法】基于同源性搜索策略,以拟南芥WOX基因蛋白为参考序列,进行苦荞全基因组比对,获得苦荞WOX基因家族成员蛋白及核酸序列。基于蛋白同源性及保守结构域分析,鉴定出苦荞WOX基因家族所有成员。同时使用TBtools软件展示FtWOXs家族成员基因结构、保守结构域及启动子顺式作用元件特征。比较分析WOX基因家族成员在苦荞与拟南芥之间的基因组共线性。基于邻近法,利用MEGA X软件构建苦荞、拟南芥和水稻WOX基因家族成员蛋白序列系统进化树。以MS+2,4-D 3.0 mg·L-1+6-BA 1.0 mg·L-1为愈伤诱导培养基,下胚轴为外植体,选取70份苦荞品种诱导愈伤组织,评价不同基因型的出愈率。qRT-PCR比较分析高、低出愈率苦荞品种间FtWOXs基因表达水平。基于Pearson相关系数分析出愈率与FtWOXs基因家族成员表达相关性。【结果】共鉴定出30个苦荞WOX基因成员,在苦荞8条染色体上呈现不均匀分布。系统进化树表明30个苦荞WOX基因可划分为3大类,不同类群中WOX基因包含不同的保守结构域,主要的保守结构域为HD(Homeodomain)、START和MEKHLA结构域。保守基序分析表明,FtWOXs基因家族成员所含保守基序数目的范围为2—10个。基因结构分析表明,FtWOXs基因家族成员所含外显子数目的范围为2—18个。顺式作用元件分析表明FtWOXs基因启动子富含26个不同种类的顺式作用元件。系统进化分析表明,30个苦荞、15个拟南芥和12个水稻WOX基因家族成员可分为3类,其中第3类为苦荞独有。基因组共线性分析表明,6个WOX基因在苦荞和拟南芥之间存在基因组共线性。表达模式及相关性表明,FtWOX1/FtWOX12/FtWOX22/FtWOX23/FtWOX24与苦荞出愈率存在正相关性。【结论】苦荞FtWOXs成员存在丰富的序列变异特征,不同苦荞基因型中WOX基因表达水平及出愈率存在明显差异和一定的相关性,揭示不同苦荞WOX基因具有潜在的功能多样性。

关键词: 苦荞, WOX基因, 愈伤组织, 基因表达

Abstract:

【Objective】 This study aimed to identify the whole genome WOX (WUSCHEL-related home obox) gene family in Tartary buckwheat and reveal the correlation with sequence characteristics of its gene family members, gene expression pattern and the rate of callus induction. It provides a theoretical basis for breaking through the regeneration and genetic transformation problem of Tartary buckwheat. 【Method】 The protein and nucleic acid sequence of the WOX gene family members in Tartary buckwheat were obtained by homology blast and the sequence of Arabidopsis WOX genes were served as reference. Based on protein homology and conserved domain analysis, all members of Tartary buckwheat WOX gene family were identified. The TBtools software was used to further demonstrate the characteristics of the WOX genes in Tartary buckwheat, including gene structure, conserved domain and cis-acting element. Genomic collinearity of WOX gene family members between Tartary buckwheat and Arabidopsis thaliana was analysed. Based on proximity method, the MEGA X software was used to perform phylogenetic tree of these WOX genes in Tartary buckwheat, Arabidopsis and rice. The hypocotyl explants of 70 Tartary buckwheat varieties were cultured with MS+2,4-D 3.0 mg·L -1+6-BA 1.0 mg·L-1 for callus induction and the callus emergence rate of different genotypes was evaluated. The FtWOX gene expression level was performed by qPCR to compare the different Tartary buckwheat varieties with high and low callus yield. The correlation between callus rate and FTWOXS gene family members was analysed based on Pearson correlation coefficient. 【Result】 A total of 30 WOX genes were identified in Tartary buckwheat and they were unevenly distributed on 8 chromosomes. The 30 Tartary buckwheat WOX genes could be divided into three groups by phylogenetic tree. The WOX genes contained different conserved domains in different groups, and the main conserved domains were HD(Homeodomain), START and MEKHLA. The conserved motif analysis showed that the conserved motif number of FtWOX genes may contain 2 to 10 motifs, and the gene structure analysis showed that the number of exons contained in the genes between 2 to 18. Promoter elements analysis showed 26 different kinds of cis-acting elements in the 30 WOX genes. The phylogenetic analysis showed that 30 Tartary buckwheat, 15 Arabidopsis thaliana and 12 rice WOX gene family members could be divided into three categories, of which the third group is unique to Tartary buckwheat. The collinearity analysis showed that six WOX genes were genomic collinearity between Tartary buckwheat and Arabidopsis thaliana. Expression pattern and correlation analysis show that the expression level of FtWOX1/FtWOX12/FtWOX22/FtWOX23/ FtWOX24 has positive correlation with the callus induction. 【Conclusion】 Collectively, these data suggest that the Tartary buckwheat FtWOX members showed abundant sequence variation characteristics. The expression level and callus rate of WOX gene in different Tartary buckwheat genotypes were significantly different and correlated to some extent, suggesting that different Tartary buckwheat WOX genes had potential functional diversity.

Key words: Tartary buckwheat, WOX gene family, callus induction, gene expression