Identification of a methyl jasmonate-responsive region in the promoter of a lipoxygenase 1 gene expressed in barley grain.
A genomic DNA fragment was isolated containing 5' upstream sequences and part of the open reading frame corresponding to the lipoxygenase 1 cDNA (LoxA) expressed in barley grains during development and germination. Lox1 transcription was shown to be methyl jasmonate (MeJA)- and wound-inducible in leaves, but Lox1 transcripts were not detected in mildew-infected leaves, although this is a commonly observed response to pathogenic attack in various plants. Transient gene expression assays were used to identify a promoter region involved in MeJA-responsive expression. Analysis of 5' and 3' promoter deletions indicated that sequences between -363 and -294 conferred MeJA-responsive expression. Deletions/replacements covering this part of the promoter further defined a MeJA-responsive region between -331 and -291. Insertion of the region -328 to -293 into the constitutive CaMV 35S promoter conferred MeJA-responsive expression. The 36 bp fragment contains the motif TGACG as inverted repeats, which has been previously identified as a binding site for bZIP transactivating factors. Site-directed mutagenesis on these TGACG motifs abolished MeJA-responsive expression, clearly identifying them as MeJA-responsive elements. Sequence comparisons found no similar motif in other characterized promoters of MeJA-inducible genes, but suggested a common spatial structure which may serve as a binding site for transacting factors involved in the MeJA signal transduction pathway.
Rouster
J
J
Carlsberg Research Laboratory, Copenhagen, Denmark. jaro@crc.dk
Leah
R
R
Mundy
J
J
Cameron-Mills
V
V
D000040:Abscisic Acid / Q000494:pharmacology; D000085:Acetates / Q000494:pharmacology*; D001483:Base Sequence; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000494:pharmacology*; D004790:Enzyme Induction; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D001467:Hordeum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008084:Lipoxygenase / Q000096:biosynthesis* / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D054883:Oxylipins; D010937:Plant Growth Regulators / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping
D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D011993:Recombinant Fusion Proteins; D000040:Abscisic Acid; C072239:methyl jasmonate; D008084:Lipoxygenase