Optimization of Flavonol Synthase (FLS) gene amplification from Melastoma decemfidum via PCR

Abstract

Flavonol synthase (FLS) converts dihydroflavonol (dihydroquercetin and dihydrokaempferol) to flavonol (quercetin and kaempferol) in flavonoid biosynthetic pathway. Leaves and flower extracts of Melastoma decemfidum are rich in flavonoids and possess strong antioxidant and antitumor activities. In this study, FLS gene from Melastoma decemfidum was isolated using PCR method. Genomic DNA was extracted from leaf and stem using CTAB method and FLS gene was amplified through degenerate primers using PCR method. Result showed that the size of genomic DNA was =10kb and the A260/A230 and A260/A280 ratios were ranged from 2.03 to 2.13 and 1.85 to 1.97, respectively. The highest DNA yield was obtained from leaf extracts with 437 ng/µl. Three PCR product were amplified with sizes of approximately 200bp, 1500bp and 900bp, at optimal PCR condition. The average full-length of FLS cDNA sequence in different species is ranged from 1 t0 1.4kb. A multicopy gene in plants encodes FLS, and the different copies are expressed in either an organ- or species-specific pattern. Future study such as isolation and verification of FLS gene is required. Then, characterization will be needed in order to elucidate the function of the flavonol synthase that catalyzes the biosynthesis of flavonols in M. decemfidum.