Scientists Develop Yellow-colored African Violets

For the first time, scientists were successful in using genetic engineering of aurone pigments biosynthesis pathway to produce the yellow color in the petals of the white African violet.

African violets are found in different colors except for yellow. For this study, the scientists used the S. Jolly Diamond cultivar which has white petals. Their objective was to change the petals' colors from white to yellow by using the aurone pigment biosynthesis pathway. Aurone is a class of rare flavonoids that is yellow and is present in only a few species. The scientists simultaneously expressed the chalcone 4'GCT and AS1 genes without the need for silencing anthocyanin biosynthesis pathway genes via both transient and stable transfer methods.

During the trials, 15 transgenic plants were produced using stable gene transfer. The T₀ plants underwent PCR, qRT-PCR, and Southern Blot analysis to verify the transformation, expression, and integration of genes. The scientists also noted that the two genes' simultaneous expression in the white-colored petals, which as chalcone, contributed to the accumulation of Aureusidin 6-O-glucoside as the final compound of aurones. Thus, as the African violet petals produced chalcone, the existence of malonyl transferase caused the accumulation of aurones which led to the yellow color of the petals. Their study opened the possibility for other researchers to use the same method on other ornamental plants to produce yellow petals.