Cloning and Induction of Phenylalanine Ammonia-lyase Gene from Salvia miltiorrhiza and Its Effect on Hydrophilic Phenolic Acids Levels

Abstract

Aim To Clone phenylalanine ammonia-lyase gene (designated as Smpal) from Salvia miltiorrhiza and to study its expression, induction and effect on hydrophilic phenolic acids levels in S. miltiorrhiza. Methods Smpal was cloned and well characterized from S. miltiorrhiza, using Rapid Amplification of cDNA ends (RACE) technology. The expression of Smpal could be induced by MeJA, SA and GA3. The metabolite content was determined by LC-MS. Results The full-length of Smpal cDNA was 2354 bp in size and contained an ORF of 2133 bp encoding 711 amino-acids, a 5′ untranslated region (UTR) of 21 bp, and a 3′ UTR of 171 bp. RT-PCR analysis revealed that the Smpal expressed constitutively in all test plant organs with the highest expression level in root, followed by stem and leaves. Conclusion The deduced Smpal shared an overall identity of 62.4%-93% with other known pals. Southern hybridization analyses suggested that Smpal belonged to a multigene family. The fluctuation of RA and LAB content was directly correlated with pal expression.