CLONING AND SEQUENCING OF FLAVONOL SYNTHASE IN LYCIUM

In Chinese medicine, many plant species including Lycium chinensis and L. barbarum are used for medicinal purposes. L. pallidum, L. berlandieri, and L. torreyi are related shrubs found in the southwest United States and have been used traditionally by Native Americans as food and as medicine. Flavonoids, which are commonly found in Lycium species, are among the chemicals demonstrated to have medicinal value. Our project was to investigate which of the Lycium species has the richest medicinal value by examining synthesis of the two most common flavonoids, quercetin and rutin. We compared the three native species, L. pallidum, L. torreyi, L. berlandieri, to the two Asian species, L. barbarum and L. chinensis.  The five species were collected from various locations and dried. Nucleic acids were extracted from all five species in order to examine flavonol synthase, a central enzyme in the flavonol metabolic pathway. Literature has reported that other plant species have a family of five genes that encode flavonol synthase and flavonol synthase-like proteins. We performed PCR using degenerate primers for the five known flavonol synthase genes from genomic DNA extracted from the Lycium species. Next we performed reverse transcription followed by PCR to examine mRNA expression of flavonol synthase. In future studies, the goal will be to demonstrate that flavonol synthase expression levels correlate with quercetin and rutin levels in the plant. Research supported by R25 GM048998-13.