Subcellular Localization Studies of Three Phenylalanine Ammonia-Lyases and Cinnamate 4-Hydroxylase from Scutellaria Baicalensis Using GFP Fusion Proteins

The localization of three phenylalanine ammonia-lyases (PAL1, -2 and -3) and Cinnamate 4-Hydroxlase (C4H) of Scutellaria baicalensis was examined in onion epidermal cells. These genes encode key enzymes in the phenylpropanoid pathway for the synthesis of flavones. In our previous research, we isolated coding DNA for these genes from S. baicalensis, a medicinal herb rich in flavones with biological and pharmacological properties. We observed that SbPAL2, SbPAL3 and SbC4H proteins localize to the endoplasmic reticulum; however, SbPAL1 was a cytosolic protein. Unlike SbPAL2 and SbPAL3, SbPAL1 may be expected to have a different function in the flavone biosynthetic pathway.