Correlation analysis between single nucleotide polymorphism of β-amyrinsynthase and content of glycyrrhizic acid in Glycyrrhiza uralensis Cloning, prokaryotic expression, and functional identification of β-amyrin synthase cDNA of Psammosilene tunicoides Gene cloning and expression level of bAS and their correlation with content of saponins in Eleutherococcus senticosus Cloning of β-amyrin synthase gene from Panax quinquefolius and its bioinformatics analysis Impacting of polymorphism of β-amyrin synthase from Glycyrrhiza uralensis on its catalytic efficiency