王新亮 彭玲 王健 贾晶晶 唐立平

摘要： 为了解苹果Dof转录因子家族的生物学信息与功能，利用苹果基因组GDDH13 v1.1检索及RNA-seq转录本重构找到51个Dof 基因，并通过 Pfam 和SMART检测确认，进一步对这些Dof基因进行全面分析。结果表明，除MD07G1265700外，其他50个Dof蛋白均含有一个明显的Dof结构域，且有一个CX2CX21CX2C基序。这些Dof基因编码氨基酸数为163～523，相对分子质量为18 210～55 800，等电点为5.01～10.30，多数Dof成员定位于细胞核中， 少数定位于叶绿体或线粒体中。组织特异表达显示多数Dof 基因在营养器官中的表达量高于生殖器官，而MD01G1084700、MD07G1153300、MD08G1040100、MD15G1034500基因在未成熟的果肉中表达量最高。盐碱胁迫下，除MD05G1023800基因没有检测到表达外，其他Dof基因的表达均受盐碱胁迫影响，只是响应强度和时间有差异，基因表达显著上调的有7个，显著下调的有15个。该研究结果为进一步揭示苹果Dof转录因子生物功能奠定了理论基础。

关键词： 苹果;Dof基因;转录因子;表达分析;生物信息学

中图分类号： S661.1  文献标识码： A  文章编号： 1000-4440（2021）02-0480-13

Abstract： In order to understand the biological information and function of apple Dof transcription factor family， 51 Dof genes were found by searching apple genome GDDH13 v1.1 and RNA-seq transcripts reconstruction， and they were confirmed as members of Dof transcription factor family by Pfam and SMART detection. The Dof genes were generally analyzed furtherly. The results showed that， besides MD07G1265700， the other 50 Dof proteins all contained an obvious Dof domain and a CX2CX21CX2C motif. The number of amino acids encoded by Dof gene ranged from 163 to 523， and the relative molecular weight ranged from 18 210 to 55 800， while the isoelectric point ranged from 5.01 to 10.30. Most of the Dof proteins were located in the nucleus， and a few of them were located in the chloroplast or mitochondria. The results of tissue-specific expression showed that the expression level of most of the Dof genes expressed in vegetative organs were higher than in reproductive organs， while the expression levels of MD01G1084700， MD07G1153300， MD08G1040100 and MD15G1034500 were the highest in immature fruit flesh. Under saline-alkali stress， except for MD05G1023800 gene， the expression of other Dof genes were affected by saline-alkali stress， but the intensity and time of response were different. There were seven Dof genes significantly up-regulated and 15 Dof genes significantly down regulated. The research results lay a theoretical foundation for further study on the biological function of Dof transcription factor in apple.

Key words： apple;Dof gene;transcription factor;expression analysis;bioinformatics

蘋果（Malus pumila Mill.）是蔷薇科中重要的果树之一，与其他果树相比，具有种植面积大、货架期长等特点，苹果在中国的种植面积和产量均为世界首位。土壤盐碱、干旱、倒春寒等非生物胁迫制约着苹果产业的发展[1]。

Dof （DNA binding with one finger）蛋白是一类植物特有的转录因子[2]，其N端含有一个由50～52个氨基酸组成的高度保守的锌指结构——Dof结构域，此结构域中含有1个高度保守的CX2CX21CX2C基序。Dof蛋白既能与特定的DNA序列结合调节基因表达，也能与某些蛋白质相互作用，参与植物生长发育及非生物胁迫响应的调控[3-5]。……