目的克隆铁皮石斛Dendrobium officinale ABC(ATP-binding cassette)转运蛋白F家族基因并进行生物信息学分析。方法利用RACE从铁皮石斛叶片cDNA中分离ABC基因,并进行编码蛋白相对分子质量、等电点、结构域、信号肽、跨膜域及亚细胞定位等生物信息学分析;采用DNASTAR和MEGA6进行氨基酸多序列比对和分子进化分析;借助实时荧光定量PCR技术检测基因组织表达模式。结果从铁皮石斛中分离到2个F家族ABC转运蛋白基因DoABCF1和DoABCF2(Gen Bank注册号KU160474和KU160475),全长为2 104 bp和2 193 bp,各编码1条由600和659个氨基酸组成的肽链,相对分子质量67 030和74 140,等电点6.20和5.71;DoABCF1和DoABCF2蛋白均包含2个保守的ABC结构域(分别为74~314、385~600和65~323、392~607)和多个基元;2个蛋白不含信号肽或跨膜域,预测均定位在叶绿体。2个基因与植物F家族ABC转运蛋白基因相似性高达80%以上,与玉米和水稻等单子叶植物F家族ABC转运蛋白基因亲缘关系较近。DoABCF1和DoABCF2基因转录本在石斛3个器官中差异表达且均在叶中高度表达,茎和根中相对表达量差异不显著;以茎为校正样本,前者在根中相对表达量为茎中的1.74倍,后者在叶中表达量为茎中的3.44倍。结论成功获得DoABCF1和DoABCF2基因全长cDNA,二者在铁皮石斛叶中的高表达特征暗示其可能在铁皮石斛生长发育过程中起一定作用。 Objective To clone Dendrobium officinale ABC (ATP-binding cassette) transporter F family gene and perform bioinformatics analysis. Methods ABC gene was isolated from cDNA of Dendrobium officinale with RACE and bioinformatics analysis including relative molecular mass, isoelectric point, domain, signal peptide, transmembrane domain and subcellular localization of the protein was carried out by RACE. Amino acids Multiple sequence alignment and molecular evolution analysis; detection of gene expression patterns by real-time fluorescence quantitative PCR. Results Two F family ABC transporter genes, DoABCF1 and DoABCF2 (Gen Bank accession numbers KU160474 and KU160475), were isolated from Dendrobium officinale. The full-length genes were 2 104 bp and 2 193 bp, and each encoded 1 fragment consisting of 600 and 659 amino acids Of the peptide chains, with molecular weights of 67 030 and 74 140, and isoelectric points of 6.20 and 5.71; DoABCF1 and DoABCF2 both contained two conserved ABC domains (74-314, 385-600 and 65-332, 607) and multiple motifs; the two proteins do not contain signal peptide or transmembrane domain and are predicted to be located in the chloroplast. The similarity of the two genes to the F family ABC transporter gene in plants was as high as 80%, which was close to the F family ABC transporter gene of monocotyledonous plants such as maize and rice. The transcripts of DoABCF1 and DoABCF2 were differentially expressed in three organs of Dendrobium and all of them were highly expressed in leaves. There was no significant difference in the relative expression level between stems and roots. The stems were used as the calibration samples, 1.74 times, which is 3.44 times higher than that in the stem. Conclusion The full-length cDNA of DoABCF1 and DoABCF2 gene was successfully obtained. The high expression of both DoABCF1 and DoABCF2 genes suggests that they may play a role in the growth and development of Dendrobium candidum.