ISOLATION, CHARACTERIZATION AND EXPRESSION OF PAL GENE FAMILY IN ARTICHOKE

Artichoke is well known from ancient times both as an edible crop and a medicinal remedy for several applications. Its properties are mostly due to the phenolic compounds it contains; in fact artichoke leaf extracts, rich in these compounds, are widely used in popular medicine. Phenylalanine ammonia-lyase (PAL) is the enzyme involved in the first step of the phenylpropanoid biosynthesis pathway, catalyzing the deamination of phenylalanine. In most plants, this enzyme is usually coded by more than one gene. Starting from database sequences, primers were designed to amplify artichoke DNA fragments. These amplicons were cloned and sequenced. Partial nucleotide sequences showed a high similarity with pal genes from other species, and were used as molecular probes for Southern analysis and to screen a genomic library in order to isolate the artichoke pal gene family. At present, four members of the pal family have been isolated and characterized. The analysis of expression indicates a different level of expression of pal genes in different artichoke organs.