Molecular marker of high glycyrrhizic acid content based on the SNPs of liquorice IPT gene.

Previous studies found that cytokinins (CTKs) are able to significantly promote glycyrrhizic acid (GA) accumulation. This study analyzed the correlation between the contents of GA and CTKs in 98 one-year-old liquorice plants by the combination of high-performance liquid chromatography and enzyme-linked immunosorbent assay. The full length of the liquorice IPT gene was cloned and the Single-nucleotide polymorphisms (SNPs) of the IPT gene in the samples were obtained. The molecular marker of high GA content was found by performing correlation analysis on the SNPs of the IPT gene. Results indicated that the contents of GA and CTKs were positively correlated. The full-length sequence of the IPT gene was 1002 bps, and five SNPs were found in the 98 liquorice samples. One of five SNPs was 348 bps, exhibiting missense mutation and the rest displaying synonymous mutations. In the five SNPs, 348 bps was primarily associated SNP, whereas 821 and 848 bps were auxiliary associated SNP. The findings of this study provided insight into the molecular mechanism of GA genetic variation, serving as basis for improving the GA content in cultivated liquorice and the good varieties breeding.