Molecular cloning and characterization of a phenylalanine ammonia-lyase gene (LrPAL) from Lycoris radiata.

LrPAL is a novel full-length cDNA isolated from Lycoris radiata by degenerate oligonucleotide primer PCR (DOP-PCR), 3'- and 5'-RACE approaches, harbours an open reading frame (ORF) encoding a 708 amino acid product. Sequence alignment showed that the deduced amino acid sequence of LrPAL shared more than 80% identity with other PAL sequences reported in Arabidopsis thaliana and other plants. RT-PCR revealed that LrPAL transcripts were higher in bud flowers and wilting flowers (5 days after blooming) than in blooming flowers. The transcript levels of LrPAL in leaves were significantly induced by methyl jasmonate (MJ) and nitric oxide (NO), and salicylic acid (SA). Similarly, HPLC analysis showed that galantamine (GAL) content was also higher in bud flowers and wilting flowers than in blooming flowers. The GAL content in leaves was significantly induced by MJ and NO, and inhibited by SA. This study enables us to further elucidate the role of LrPAL in the biosynthesis of GAL in Lycoris radiata at a molecular level.