Abstract: Auxin response factor(ARF)is a transcription factor family that mediates auxin signaling and regulates various biological processes. To investigate the ARF gene family members and their roles in response to high temperature and drought stress, the phylogenetic and expression patterns of the ARF gene family members in Huperzia serrata were analyzed using full-length transcriptome and RNA-seq data. Based on bioinformatics analysis, the physicochemical properties, domains, conserved motifs, phylogeny, tissue expression patterns, and expression patterns of the ARF gene family under high temperature and drought stress were analyzed. The results were as follows:(1)A total of 24 ARF family members were screened in the full-length transcriptome of H. serrata, all of which were acidic proteins and hydrophilic proteins.(2)Subcellular localization prediction revealed that 24 HsARF were all localized in nucleus.(3)Phylogenetic analysis revealed that HsARF had a distant genetic relationship with angiosperms Arabidopsis and rice, and only share two common ARF ancestors with higher flowering plants.(4)Domain analysis revealed that, except for HsARF18/23/24, most HsARF had B3 domains. Analysis of secondary structure found that the highest proportion of HsARF protein was random curling, followed by elongated chains and α-helix. Three-dimensional(3D)protein structure prediction model used in the 24 HsARF proteins was only four.(5)RNA-seq analysis showed that the expression levels of 7 HsARF were high in all detected organs. The expression levels of 10 HsARF in stems were higher than those in roots and leaves. Otherwise, the expression levels of HsARF13 and HsARF14 in leaves were lower than those in roots and stems.(6)The expression levels of HsARF undergo significant changes under high temperature and drought stress, with 18 HsARF being induced to varying degrees by high temperature stress, 7 HsARF responded to drought stress, with 3 HsARF induced by drought, while 4 HsARF inhibited by drought. The results provide theoretical references for the functional and biological breeding study of ARF gene family in H. serrata.

Key words: Huperzia serrata, auxin response factor(ARF), phylogenetic analysis, full-length transcriptome, abiotic stress

摘要： 生长素响应因子(ARF)是介导生长素信号传导并调节多种生物学过程的转录因子家族。为探究蛇足石杉ARF基因家族成员及其在高温和干旱胁迫响应中的作用,该研究利用全长转录组和RNA-seq数据,分析蛇足石杉ARF基因家族成员的系统发育及表达模式,并通过生物信息学分析,对ARF基因家族的理化性质、结构域、保守基序、系统发育、组织表达模式及高温和干旱胁迫下的表达模式进行分析。结果表明:(1)在蛇足石杉全长转录组中共筛选出24个ARF家族成员,均为酸性蛋白且均为亲水蛋白。(2)亚细胞定位预测显示,所有24个HsARF均定位于细胞核。(3)系统发育分析发现,HsARF与被子植物拟南芥和水稻亲缘关系较远,与高等开花植物只有2个共同的ARF祖先。(4)结构域分析发现,除HsARF18/23/24外,大多数HsARF有B3结构域。二级结构分析发现,HsARF蛋白占比最多的为无规卷曲,其次为延伸链和α-螺旋。24个HsARF蛋白中所用的三级结构模型只有4种。(5)RNA-seq分析显示,7个HsARF在所有检测的组织中表达量均较高,10个HsARF在茎中的表达量高于根和叶,而HsARF13和HsARF14在叶中的表达量低于根和茎。(6)HsARF在高温和干旱胁迫下表达量发生显著变化,其中18个HsARF基因不同程度高温胁迫诱导,有7个HsARF基因响应干旱胁迫,其中有3个HsARF基因受干旱诱导,有4个HsARF基因受干旱抑。该研究结果为蛇足石杉HsARF基因的功能和生物育种提供了理论参考。

关键词: 蛇足石杉, 生长素反应因子(ARF), 系统发育分析, 全长转录组, 非生物胁迫