Cloning And Expression Analysis Of Chalcone Isomerase Gene From Astragalus Membranaceus

Astragalus membranaceus as a common medicinal material has a very wide clinical application.Isoflavone is one of its main active ingredients,but its molecular biosynthesis mechanism is not yet clear.In the metabolic pathway of phenylpropane,Chalcone isomerase(CHI)is a key enzyme that catalyzes the synthesis of isoflavones.In this paper,Astragalus membranaceus was used as a material to clone the CHI gene and sequence analysis was carried out to explore its expression characteristics under different organ and environmental stresses.It is the role of the CHI gene in the biosynthesis of flavonoids in Astragalus membranaceus Provide a certain theoretical basis.The results showed that the cDNA of Astragalus membranaceus CHI gene(AmCHI)is 910 bp in length(Genbank accession number is KY0862871),the open reading frame is 660 bp,encoding 219 amino acids,its molecular weight is 24021.42 Da,and its isoelectric point is 5.41.AmCHI protein is located in the cytoplasm and has no signal peptide.It is a stable hydrophilic protein.Its amino acid sequence is highly similar to legumes,and it is presumed to be Type Ⅱ.Real-time fluorescence quantitative PCR analysis showed that AmCHI’s constitutive expression and induced expression were positively correlated with isoflavone content,so AmCHI played an important role in astragalus isoflavone biosynthesis.