Table 2.
Examples of metabolic engineering of the flavonoid pathway.
| Engineered species | Target gene/gene donor | Methodology/phenotype | References |
|---|---|---|---|
| Cyclamen persicum | CpF3′5′H | Suppression by antisense. | Boase et al., 2010 |
| Flowers turned from purple to red/pink | |||
| Nicotiana tabacum (tobacco)-Arabidopsis | O-methyltransferase from S. bicolor (SbOMT3). Stilbene synthase from peanut (AhSTS3) | Heterologous co-expression. | Rimando et al., 2012 |
| Production of resveratrol. | |||
| Decrease in flavonoids | |||
| B. napus | isoflavone synthase from soybean (GmIFS2) | Accumulation of genistein in leaves. | Li et al., 2011 |
| Decreased levels of flavonols. | |||
| Citrus paradise (grapefruit) | Chalcone synthase-Chalcone isomerase | Over-expression and suppression. | Koca et al., 2009 |
| Decreased level of naringin in leaves. | |||
| Nicotiana tabacum (tobacco)-Petunia hybrida | ZmLc (bHLH) | Accumulation of anthocyanins in tobacco flowers and petunia leaves | Lloyd et al., 1992; Bradley et al., 1998 |
| Solanum lycopersicum (tomato) | ZmC1 (R2R3 MYB) – ZmLc (bHLH) | Heterologous co-expression under a fruit-specific promoter. | Bovy et al., 2002 |
| Increase of flavonols and flavanones in fruits. | |||
| Solanum lycopersicum (tomato)-Nicotiana tabacum (tobacco) | SlANT1 (R2R3-MYB) | Purple leaves | Mathews et al., 2003 |
| Solanum lycopersicum (tomato) | A. majus Del (bHLH) and Ros1 (MYB-related) | Heterologous co-expression under a fruit-specific E8 promoter. | Butelli et al., 2008 |
| High levels of anthocyanin in fruits. | |||
| Nicotiana tabacum (tobacco) | PAP1-PAP2 from A. thaliana | Ectopic accumulation of anthocyanins. | Borevitz et al., 2000 |
| Purple plants |