Identification and characterization of a novel barley gene that is ABA-inducible and expressed specifically in embryo and aleurone

A screening of a cDNA library of abscisic acid (ABA)-treated barley aleurone using a polyclonal anti-idiotypic antibody that had been made against an anti-ABA monoclonal antibody resulted in the isolation of a cDNA clone aba45. Northern blot analysis showed that aba45 was up-regulated by ABA and down-regulated by gibberellin. Aba45 mRNA was not detectable in barley roots, stems and leaves and was most abundant in developing aleurone and embryo. Analysis of the 5′ genomic sequence of aba45, isolated using a nested PCR procedure, revealed a conserved ABA response complex that consists of an ACGT-core element and a conserved gibberellin response element.