Cloning and expression analysis of Ipomoea batatas (L.) Lam. gene IbPAL

In this research, the phenylalanine ammonia-lyase gene IbPAL was cloned based on transcriptome information related to chlorogenic biosynthesis metabolism in Ipomoea batatas (L.) Lam. Its amino acid (aa) structure was also analyzed by means of protein sequence alignment, phylogenetic analysis, secondary and three-dimensional protein structure prediction, and transmembrane domain and promotor analysis. The expression patterns of IbPAL in roots, stems, meristems, and leaves were further determined by qRT-PCR, with expression locations validated by subcellular experiments. Results showed that the CDS of IbPAL was 2130 bp in length, encoding 709 amino acids. Homologous alignment of the amino acid sequences indicated that IbPAL had high similarity (> 80%) with other reported species. Its protein mainly consisted of α-helixes and random coils and was predicated to have a transmembrane domain. Its promoter contained several cis-elements. IbPAL was mainly expressed in stems and meristems and its expression levels in the four tissues of sweet potato variety ‘EC16’ were significantly higher than that in other varieties and lines. The subcellular experiments indicated that the gene was expressed in the cell nucleus and cytomembrane.