Objective: To reveal the 3-hydroxy-3-methylglutary-coenzyme A reductase (HMGR) gene polymorphism of Glycyrrhiza uralensis, and the correlation between HMGR gene polymorphism and the content of glycyrrhizic acid.
Method: Liquorice plants containing different content of glycyrrhizic acid were used as materials. RT-PCR was used to amplify their HMGR gene sequences, which were connected with vector pMD19-T for clone sequencing. Multiple alignments were performed to analyse HMGR gene polymorphism of G. uralensis. Then the correlation between HMGR gene polymorphism and the content of glycyrrhizic acid was revealed.
Result: HMGR gene sequences polymorphism included codon mutation, base substitution mutation, copy number polymorphism and allele heterozygosity. There were 4 types of mutations in HMGR gene coding amino acid sequences, namely -HSL, -HSV, GALLV, GALSV. Among them, -HSV type was common in liquorice plants, -HSL type only existed in liquorice plants with low content of glycyrrhizic acid, and GALSV type only existed in liquorice plants with high content of glycyrrhizic acid.
Conclusion: HMGR gene sequences of G. uralensis are highly polymorphic and related to the content of glycyrrhizic acid.