GENOMIC SEQUENCE AND MAPPING OF A METHYLJASMONATE-INDUCED O-METHYLTRANSFERASE FROM BARLEY (HORDEUM-VULGARE L.)

We have isolated a genomic clone corresponding to a caffeic acid O-met hyltransferase (COMT) from barley (Hordeum vulgare L.) using a cDNA fo r a previously described jasmonate-regulated mRNA showing homology to COMT. Primer extension was used to characterize the 5' end of the mRNA while the 3' end, intron/exon structure and other features of the seq uence were deduced by comparison to the cDNA sequence and/or conserved motifs. The gene is mapped to chromosome five and is absent in the ba rley cultivar Morex. Southern and northern analyses suggest that no di fferences in genomic structure and jasmonate inducibility exist betwee n the barley cultivar Salome (source of the cDNA clone) and Igri (sour ce of the genomic clone). This genomic clone is thus suitable for prom oter studies with respect to jasmonate induction.