Regulation of the Osem gene by abscisic acid and the transcriptional activator VP1: analysis of cis-acting promoter elements required for regulation by abscisic acid and VP1
Article first published online: 5 MAR 2002
The Plant Journal
Volume 7, Issue 6, pages 913–925, June 1995
How to Cite
Hattori, T., Terada, T. and Hamasuna, S. (1995), Regulation of the Osem gene by abscisic acid and the transcriptional activator VP1: analysis of cis-acting promoter elements required for regulation by abscisic acid and VP1. The Plant Journal, 7: 913–925. doi: 10.1046/j.1365-313X.1995.07060913.x
- Issue published online: 5 MAR 2002
- Article first published online: 5 MAR 2002
- Received 12 December 1994; revised 7 February 1995; accepted 27 February 1995.
- Cited By
Osem, a rice gene homologous to the wheat Em gene, which encodes one of the late-embryogenesis abundant proteins was isolated. The gene was characterized with respect to control of transcription by abscisic acid (ABA) and the transcriptional activator VP1, which is involved in the ABA-regulated gene expression during late embryo-genesis. A fusion gene (Osem-GUS) consisting of the Osem promoter and the bacterial β-glucuronidase (GUS) gene was constructed and tested in a transient expression system, using protoplasts derived from a suspension-cultured line of rice cells, for activation by ABA and by co-transfection with an expression vector (35S-Osvp1) for the rice VP1 (OSVP1) cDNA. The expression of Osem-GUS was strongly (40- to 150-fold) activated by externally applied ABA and by over-expression of (OS)VP1. The Osem promoter has three ACGTG-containing sequences, motif A, motif B and motif A′, which resemble the abscisic acid-responsive element (ABRE) that was previously identified in the wheat Em and the rice Rab16. There is also a CATGCATG sequence, which is known as the Sph box and is shown to be essential for the regulation by VP1 of the maize anthocyanin regulatory gene C1. Focusing on these sequence elements, various mutant derivatives of the Osem promoter in the transient expression system were assayed. The analysis revealed that motif A functions not only as an ABRE but also as a sequence element required for the regulation by (OS)VP1.