甜橙Dof基因家族鉴定与表达分析

杨杰 陈蓉 胡文娟 吴巧玲 佟晓楠 李兴涛

摘  要：为研究甜橙单锌指DNA结合蛋白（DNA binding with one zine finger， Dof）家族的进化关系和该家族成员在不同花期甜橙品种花芽和叶片的表达模式，利用甜橙基因组筛选鉴定CsDof基因家族成员，对甜橙Dof基因家族成员及启动子区进行生物信息学分析，并使用qRT-PCR检测不同花期甜橙品种中CsDof家族成员在成花时期的表达情况。共鉴定出24个CsDof基因家族成员，这些基因分布在甜橙的8条染色体上。系统进化树聚集为9个亚群，CsDofs被分在A、B1、B2、C1、C2.1、C2.2、D1和D2亚群，同一亚群的CsDofs具有相似的基因结构和基序分布。CsDofs启动子区域含大量的光响应元件和激素响应元件。qRT-PCR检测分析发现2个甜橙品种花芽和叶片组织中的CsDofs表达模式存在较大差异，对照品种‘纽荷尔’花芽和叶片中CsDof6、CsDof11、CsDof13、CsDof17和CsDof21表达量均高于早熟品种‘赣南早’，而‘赣南早’花芽和叶片中CsDof19和CsDof23表达量高于‘纽荷尔’，表明CsDofs在不同花期的甜橙中具有明显的品种表达特异性，推测CsDofs对甜橙开花时间起重要的调控作用。这些结果为阐明CsDof基因家族在甜橙花期调控中的功能提供了理论参考。

关键词：甜橙;Dof基因家族;生物信息学;基因表达

中图分类号：S666.4      文献标识码：A

Abstract： The DNA binding with one zine figer proteins （Dof） in Citrus Sinensis was identified by bioinformatics， and the evolution model and expression pattern were analyzed. Used the recently released upland C. Sinensis genomic data， Dof genes in C. Sinensis were identified by bioinformatic methods. The chromosomal localization， physicochemical properties， sequence characteristics， phylogeny， cis-acting elements and expression profile of Dof genes in C. Sinensis were systematically analyzed. We identified 24 Dof genes which were distributed on 8 chromosomes. The phylogenet-ic-tree was clustered into 9 subgroups， and CsDof genes were divided into A， B1， B2， C1， C2.1， C2.2， D1 and D2 sub-groups. The promoter region of CsDof genes contained a large number of light-responsive and hormone-responsive elements. The expression pattern of CsDof genes was different in buds and leaves of two sweet orange varieties by  quantitative real-time PCR （qRT-PCR）. The expression of CsDof6， CsDof11， CsDof13， CsDof17 and CsDof21 in ‘New-hall’ cultivars was higher than that in buds and leaves of ‘Gannan Zao’ cultivars， while that of CsDof19 and CsDof23 in ‘Gannan Zao’ cultivars was higher than that in buds and leaves of ‘Newhall’ cultivars. The CsDof genes had obvious specificity of variety expression in sweet orange at different flowering stages， it suggesting CsDof genes played an im-portant role in the regulation of flowering time. The results would provide references for clarifying the functions of CsDof gene family in the regulation of flowering stage.

Keywords： Citrus Sinensis; Dof gene family; bioinformatics; gene expression

DOI： 10.3969/j.issn.1000-2561.2021.12.013

单锌指DNA结合蛋白（DNA binding with one zine finger， Dof）是植物特有的转录因子，在调控其生长发育、开花周期等过程中发挥重要作用。Dof蛋白具有N末端高度保守Dof结构域和C末端转录调控域[1]。其中，Dof结构域为含有52个氨基酸残基的C2-C2型单锌指结构，可识别AAAG/CTTT顺式作用调控元件[2];C末端转录调控域具有不同氨基酸序列，表明其具備多种蛋白功能[3]。……