| Flower color, as the most visual impact aesthetic characteristics, is one of the importantfactors in determining the ornamental value of floricultural plants. Its potential economicvalue leads to the development of the flowers and the cut flower market. However, due to thelimited biosynthetic genes in plants, the expression of these specific set of genes, keyenzymes of substrate specificity, or influence factors, such as temporal and spatial regulationgenes lead to produce limited types of anthocyanin accumulation and demonstrate limitedflower color. Therefore, a broad spectrum of flower color is an important goal for flowerbreeding.Lilium is a monocotyledonous plants belonging to the family Liliaceae. It is also one ofthe world famous five cut flowers, and occupies very important share of the market. Due tothe lack of delphinidin-based anthocyanins in Lilium, there are no purple or blue color innature. Therefore, the creation of blue flower becomes the target of many breeders. The studymainly focused on the expression pattern of F3’5’H from Phalaenopsis hybrid ‘SuperFirebird’ and Hyacinthus orientalis ’Sky Jacket’, the transformation Phalaenopsis F3’5’Hunder the control of the chalcone synthase promoter in petunia flowers. To increase theaccumulation of delphinidin, Hyacinth DFR(HyDFR) and petunia DifF were overexpressedwith Phalaenopsis F3’5’H. We also used transient transformation of lily petals by particlebombardment with the three constructs. The main results are as followings.1. The expression patterns of F3’5’H in Phalaenopsis hybrid ‘Super Firebird’ andHyacinthus orientalis ’Sky Jacket’ were investigated. For Phalaenopsis, the results formqRT-PCR indicated that the expression level in the flowers were higher than in the vegetativeorgans. The maximum expression occurred in the stage2of five development stages,followed by the stage1, stage3and stage4, very low in the stage5and weak in the leaf. ForHyacinth, the maximum expression of F3’5’H displayed in the stems, followed by in the stage5, root, stage3, and was weak in the leaf.2. The binary vectors (p1300-pPZP-F3’5’H) that the flower-specific CHS promoter from Lilium Oriental ‘Sorbonne’(CHS pro) controlled Phalaenopsis F3’5’H (PhF3’5’H) wasintroduced into petunia. Flower color pigmentation in transgenic petunia changed from pinkto deeper pink. The results of qRT-PCR confirmed that PhF3’5’H was specifically expressedin the p1300-pPZP-F3’5’H transformants. The maximum expression displayed in the flowerlimb, then (decreasingly) in the leaf, roots and flower tube. The expression level in the anther,sepal and stem were relatively low. By contrast, the PhF3’5’H mRNA level in the flowers oftransgenic plants was approximately11-times higher than in the leaf and79-times higher thanin the stem. The expression of PhF3’5’H eventually increased the content of delphinidin.3. For co-expression analysis, PhF3’5’H was fused with HyDFR, or petunia DifF togenerate p1300-pPZP-F3’5’H-DFR and p1300-pPZP-F3’5’H-DifF, repectively. Plantstransformed with p1300-pPZP-F3’5’H-DFR showed a deeper color in the petal limb,especially in drape. A number of blue cells were also found. Flowers transformed withp1300-pPZP-F3’5’H-DifF demonstrated a slight change in flower color pigmentation, turningred compared to the controls.4. A transient transformation of lily petals was performed using particle bombardmentwith the three constructs. Transformants with p1300-pPZP-F3’5’H produced a color changefrom pink to pale purple. Simultaneous expression of PhF3’5’H and HyDFR produced adarker purple color than PhF3’5’H alone, but no color change was observed in flowertransformed with p1300-pPZP-F3’5’H-DifF. |
