光果甘草ARPI基因的克隆和生物信息学分析

Cloning and Bioinformatic Analysis of ARPI Gene from Glycyrrhiza glabra

目的:克隆光果甘草生长素/吲哚乙酸蛋白(Aux/IAA)(GgARPI)基因并进行生物信息学分析。方法:取光果甘草新鲜主根,提取RNA,通过逆转录-聚合酶链式反应(RT-PCR)克隆GgARPI基因互补脱氧核糖核酸(cDNA)序列,测序并对其进行生物信息学分析。结果:克隆得到长度为686 bp的GgARPI基因cDNA序列,包含1个585 bp的完整开放阅读框(ORF),编码194个氨基酸残基。生物信息学分析表明GgARPI编码蛋白为稳定亲水蛋白,相对分子质量21. 95 k Da,等电点6. 85,不含信号肽,无跨膜区,二级结构以无规卷曲为主,包含1个Aux/IAA蛋白超家族结构域。同源性分析表明GgARPI基因与豆科植物的亲缘关系较近,与单子叶植物谷子Setaria italica的进化关系最远。结论:首次克隆得到GgARPI cDNA序列,为进一步研究GgARPI基因的功能及其对甘草酸生物合成的分子调控机制奠定了基础。

Objective: To clone the complementary deoxyribonucleic acid(cDNA) of auxin/indole acetic acid protein(Aux/IAA) from Glycyrrhiza glabra(GgARPI) and analyze its sequence by bioinformatics.Method: RNA was extracted from fresh root of G. glabra,the cDNA sequence of GgARPI gene was cloned by reverse transcription polymerase chain reaction(RT-PCR),then sequencing and bioinformatic analysis were performed. Result: The GgARPI cDNA sequence with the full length of 686 bp was obtained from G. glabra. The full open reading frame(ORF) was 585 bp,encoding 194 amino acid residues. The bioinformatic analysis showed that the protein coded by GgARPI was a stable hydrophilic protein,with a relative molecular weight of 21. 95 k Da and isoelectric point of 6. 85. It contained no signal peptides or transmembrane domain. Its secondary structure mainly consisted of random coil. An Aux/IAA superfamily was included in the conversed domain. Homology analysis indicated that it had a close evolutionary relationship with leguminous plants,and a distant evolutionary relationship with monocotyledon,such as Setaria italica. Conclusion: GgARPI cDNA sequence is successfully cloned from G. glabra for the first time,which will lay a foundation for studying the function of GgARPI and explaining the molecular regulatory mechanism of biosynthesis of glycyrrhizic acid in G. glabra.