Abstract: Using tools such as HMMER, Pfam, and SMART, 26 PAL （phenylalanine ammonia lyase） sequences were screened from different species such as Senna tora, and analyzed for bioinformatics. The results showed that the basic characteristics of the PAL gene family of Senna tora had been formed before the isolation of monocotyledonous and dicotyledonous plants, and the six PAL members were divided into three subclasses. The secondary structure of the members of the PAL gene family of Senna tora was mainly composed of α-helixes and irregular curls, containing higher Ala, Ser, and Leu residues; there were 16 different conservative motifs, among which motif12 （containing the catalytic key sequence Ala Ser Gly） appeared in all PAL members; the promoter region contained many elements for light response, plant hormone response, and stress response. Further GO, transcriptome, and Pearson analyses had also reinforced the above analysis results, indicating that members of the PAL gene family of Senna tora were mostly concentrated in light-sensitive tissues such as leaves, stems, and flowers, and participated in diverse biological processes such as drought resistance and antibacterial activities. The above analysis results would provide a theoretical basis for the subsequent functional study of the PAL gene of Senna tora and the screening of stress resistant functional genes.

Key words: Senna tora, alanine ammonia lyase （PAL）, gene family, bioinformatics