The Effect of Chalcone Isomerase (Chi) Gene Silencing on Flavonoids Content in Petunia hybrida using RNAi Technology

have been bred with altered flower color using genetic engineering approaches. One of the most effective applications is the reduction of flower pigments by suppression of involved enzymes in their biosynthesis pathways. RNA interference (RNAi) has provided an effective tool for the knock down of genes involved in the production of flower pigments. In this study, a chi-RNAi construct was designed for chalcone isomerase (chi) gene to transform Petunia plants. Transgenic lines in one phenotype showed 5.6 fold reduction in chi expression in comparison to the control. Chalcone and naringenin were also extracted and quantified. A 24% reduction in naringenin content was obvious in all transgenic lines. Generally, the results of this research showed that RNAi technology can be used as an efficient method for silencing the flower pigments in petunia. In addition, the chalcone isomerase gene was identified as one of the effective genes in anthocyanin biosynthesis pathway in Petunia plants which is involved in the production of color in these plants; hence, chi gene silencing resulted in clear phenotypic alterations in this plant.