Isolation and Characterization of Phenylalanine Ammonia Lyase ( PAL ) Genes in Ferula pseudalliacea : Insights into the Phenylpropanoid Pathway

Phenylalanine ammonia lyase (PAL) is a key enzyme regulating the biosynthesis of the compounds of the phenylpropanoid pathway. This study aimed to isolate and characterize genes from Rech.f. (Apiales: Apiaceae) to better understand the regulation of metabolite production. Three gene isoforms ( ) were identified and cloned using the 3'-RACE technique and confirmed by sequencing. Bioinformatics analysis revealed important structural features, such as phosphorylation sites, physicochemical properties, and evolutionary relationships. Expression analysis by qPCR demonstrated the differential transcription profiles of each isoform across roots, stems, leaves, flowers, and seeds. showed the highest expression in stems, in roots and flowers, and in flowers. The presence of three isoforms of in along with the diversity of genes and their tissue-specific expression profiles, suggests that complex modes of regulation exist for phenylpropanoid biosynthesis in this important medicinal plant. The predicted interaction network revealed associations with key metabolic pathways, emphasizing the multifaceted roles of these genes. In silico biochemical analyses revealed the hydrophilicity of the FpPAL isozyme; however, further analysis of substrate specificity and enzyme kinetics can clarify the specific role of each FpPAL isozyme. These comprehensive results increase the understanding of genes in , helping to characterize their contributions to secondary metabolite biosynthesis.