Distribution of phenylalanine transaminase and phenylalanine ammonia-lyase activities in etiolated and light irradiated radish seedlings (Raphanus sativus L.).

In dark-grown Raphanus sativus seedlings the level of phenylalanine transaminase is higher in cotyledons than in root and hypocotyl. The maximum activity of phenylalanine ammonia-lyase (PAL) is found in the root. Only PAL is significantly increased by light.