Molecular Cloning and Expression Profile of a Jasmonate Biosynthetic Pathway Gene for Allene Oxide Cyclase

Hyoscyamus niger L. is a medicinal plant which produces a class of jasmonate-responsive pharma- ceutical secondary metabolites named tropane alkaloids. As a family of signaling phytohormones, jasmonates play significant roles in the biosynthesis of many plant secondary metabolites. In a jasmonate biosynthetic path- way of plants, allene oxide cyclase (AOC, EC 5.3.99.6) catalyzes the most important step. Here we cloned a cDNA from H. niger , named HnAOC (GenBank accession no.: AY708383), which was 1044 bp long, with a 747-bp open reading frame (ORF) encoding a polypeptide of 248 amino acid residues. Southern blot analysis indicated that it was a multicopy gene. RT-PCR analysis revealed that the expression of HnAOC was regulated by various stresses and elicitors, with methyl-jasmonate showing the most prominent inducement. The charac- terization of HnAOC would be helpful for improving the production of valuable secondary metabolites by reg- ulating the biosynthesis of jasmonates. DOI: 10.1134/S0026893308030047