A TGACGT motif in the 5'-upstream region of alpha-amylase gene from Vigna mungo is a cis-element for expression in cotyledons of germinated seeds

• Published in: Plant and cell physiology Vol. 42; no. 6; pp. 635 - 641
• Main Author: Yamauchi, D. (Tokyo Metropolitan Univ., Hachioji (Japan))
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01.06.2001
• Subjects: a-amylase gene; ALPHA AMYLASE; alpha-Amylases - genetics; Amino Acid Sequence; Base Sequence; CaMV35S; cauliflower mosaic virus 35S RNA; Cotyledon - enzymology; COTYLEDONS; DAI; day after imbibition started; DNA, Plant; DNA-Binding Proteins - metabolism; electrophoretic mobility shift assay; EMSA; Fabaceae - enzymology; Fabaceae - genetics; GENE EXPRESSION; GENES; GERMINATION; GUS; Key words: α-Amylase (EC 3.2.1.1) — Seed germination — Transcription factor — Vigna mungo; LUC; luciferase; Molecular Sequence Data; Nuclear Proteins - metabolism; NUCLEOTIDE SEQUENCE; Promoter Regions, Genetic; Regulatory Sequences, Nucleic Acid; RNA; SEED; Seeds - enzymology; Seeds - growth & development; Spectrometry, Mass, Fast Atom Bombardment - methods; VIGNA MUNGO; β-glucuronidase
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pce079

alpha-Amylase is expressed at high levels in cotyledons of germinated seeds of Vigna mungo. The mRNA for alpha-amylase appeared in cotyledons of the seeds at 1 d after imbibition started (DAI). Two TGACGT motifs at -445 and at -125 in the promoter region of the gene interacted with nuclear proteins from cotyledons of dry seeds and the activities were detected until 3 DAI. A transient assay with particle bombardment showed that the downstream region from -135 in the promoter was required for high level expression in the cotyledons and the activity was reduced by mutation of the TGACGT motif at -125. The activities to bind the TGACGT motifs were detected in the axes of the seeds at 1 DAI but disappeared at 4 DAI, although the mRNA for alpha-amylase in the axes appeared at 4 DAI and increased in level by 6 DAI. A transient assay experiment showed that a positive regulatory element for the expression in the axes was located in the region from -630 to -453. These results indicated that the TGACGT motif at -125 was required for high level expression of the gene in the cotyledons of the germinated seeds.