evaluation of flavonol synthase (fls) gene expression in cressa cretica l. using plant growth regulators

Background: c. cretica is a medicinal and ornamental halophytic plant which used for alterative, anthelmintic, tonic and aphrodisiac purposes. the purpose of this study was to detect the quercetin content in c. cretica and to evaluate the effects of exogenous application of abscisic acid and cytokinin hormones on fls gene expression. methods: abscisic acid and cytokinin (bap) was sprayed in twostages (8 days intervals) with two different concentration of 300 and 500 ppm. quercetin content was confirmed by hplc analysis in aerial parts of plant. results: the findings revealed that gene expression of fls increased in the second stage of abscisic acid treatment. observation showed significant differences in gene expression between treated and control samples, at level of 1%. in the first phase, there were no significant differences between the abscisic acid treated and control samples. in addition, the cytokinin treatment (500 ppm) resulted to the expression of the fls gene at 5% level, which implied that cytokinin affected the fls gene expression. conclusions: in this research, it was proved that the dihydroquercetin was present in c. cretica which changed to quercetin through the flavonol synthase enzyme.