Comprehensive, Genome-Wide Identification and Expression Analyses of Phenylalanine Ammonia-Lyase Family under Abiotic Stresses in Brassica oleracea

Phenylalanine ammonia-lyase (PAL) acts as the rate-limiting enzyme for anthocyanin biosynthesis through the phenylpropanoid pathway, a crucial component of plant secondary metabolism. The PAL gene family plays a crucial role in plants' defense and stress responses, but its in silico identification and expression analyses in Brassica oleracea under different abiotic stresses remain unexplored. In this study, nine BolPAL, seven BrPAL, four AtPAL, and seventeen BnPAL genes were obtained from the genomes of B. oleracea, Brassica rapa, Arabidopsis thaliana, and Brassica napus, respectively. Segmental duplication and purifying selection are the causes of the BolPAL gene's amplification and evolution. The BolPAL genes with comparable intron-exon architectures and motifs were grouped together in the same clade. Three categories comprised the cis-regulatory elements: abiotic stressors, phytohormones, and light. According to the results of the qRT-PCR experiments, the majority of the BolPAL genes were expressed highly under MeJA, a low temperature, and a high temperature, and they were downregulated under ABA. Under white light (100 mu mol m(-2) s(-1)) with 50, 100, or 150 mu mol m(-2) s(-1) far-red (FR), only a small number of the PAL genes were expressed at 50 and 100 mu mol m(-2) s(-1) FR, while the majority of the PAL genes were slightly elevated at 150 mu mol m(-2) s(-1) FR. This work offers a theoretical foundation for molecular breeding research to investigate the role of BolPAL genes and their role in anthocyanin biosynthesis.