CLONING, CHARACTERIZATION AND EXPRESSION OF ALLENE OXIDE CYCLASE GENE INVOLVED IN JASMONATE BIOSYNTHESIS FROM TORENIA FOURNIERI

Abstract

Jasmonates are phytohormones that play important roles in plant defense and development. Allene oxide cyclase (AOC; EC 5.3.99.6) catalyzes a crucial step in the jasmonic acid biosynthetic pathway that forms the stereoisomeric precursor cis-(+)-12-oxophytodienoic acid. In the present study, a full-length cDNA of AOC was isolated from Torenia fournieri Lind., designated as TfAOC (GenBank accession no. JF417978). The cDNA was 954 bp in length. The 723 bp open reading frame encoded a protein of 240 amino acids with a putative chloroplast targeting sequence. The predicted molecular mass and the isoelectric point of the protein were 26.16 kDa and 8.60, respectively. Phylogenetic analysis reveals that TfAOC belongs to the AOC superfamily and is highly homologous to AOC proteins from other plant species. RT-PCR analysis revealed that TfAOC mRNA was expressed in all organs of plants, with highest expression in leaves and lowest in roots. High expression level was also detected in pistils and anthers. The level of methyl jasmonate was correlated with the expression of TfAOC mRNA. These results suggest that JA is involved in the pistil and anther development in T. fournieri.