Genome-wide identification and expression analysis of phenylalanine ammonia-lyase ( PAL ) family in rapeseed ( Brassica napus L.)

Background Phenylalanine ammonia-lyase (PAL), as a key enzyme in the phenylalanine metabolism pathway in plants, plays an important role in the response to environmental stress. However, the PAL family responding to abiotic stress has not been fully characterized in rapeseed. Results In this study, we conducted a genome-wide study of PAL family, and analyzed their gene structure, gene duplication, conserved motifs, cis -acting elements and response to stress treatment. A total of 17 PALs were identified in the rapeseed genome. Based on phylogenetic analysis, the BnPALs were divided into four clades (I, II, IV, and V). The prediction of protein structure domain presented that all BnPAL members contained a conservative PAL domain. Promoter sequence analysis showed that the BnPALs contain many cis -acting elements related to hormone and stress responses, indicating that BnPALs are widely involved in various biological regulatory processes. The expression profile showed that the BnPALs were significantly induced under different stress treatments (NaCl, Na 2 CO 3 , AlCl 3 , and PEG), suggesting that BnPAL family played an important role in response to abiotic stress. Conclusions Taken together, our research results comprehensively characterized the BnPAL family, and provided a valuable reference for revealing the role of BnPALs in the regulation of abiotic stress responses in rapeseed.