The 5' UTR Negatively Regulates Quantitative and Spatial Expression From the ABI3 Promoter

Plant Mol Biol. 2004 Jan;54(1):25-38. doi: 10.1023/B:PLAN.0000028767.06820.34.

Abstract

The involvement of transcription factors Arabidopsis abscisic acid-insensitive3 (ABI3), maize viviparous1 (VP1) and Phaseolus vulgaris ABI3-like factor (PvALF) in the spatial control of storage protein gene expression is well established. However, little insight exists as to how they are themselves regulated. To address this, a 5.15 kb ABI3 upstream sequence including a 4.6 kb full-length promoter and 519 bp of 5'-untranslated region (UTR) was used to drive either beta-glucuronidase (GUS) or green fluorescent protein (GFP) expression in Arabidopsis. Expression from the full-length (- 4630/ + 519ABI3 ) and various 5'-truncated promoters was detected during embryogenesis in all lines, except those transgenic for promoter elements shorter than 364 bp. Two upstream activating regions, -3600 to -2033 and -2033 to -882, enhanced GUS expression in seeds. The -882 to -364 region was sufficient to confer seed-specific expression of GUS when fused to a - 64/ + 6CaMV 35S minimal promoter. Expression from the ABI3 promoter constructs was seed-specific, except in the presence of exogenous abscisic acid (ABA) (>0.3 microM), when GUS expression was detected in seedling roots. Excision of a 405 bp region containing three upstream open reading frames (uORFs) from the 5'-UTR dramatically increased GUS expression and debilitated constraint of reporter expression in roots. Negative regulation of ABI3 expression by the 5'-UTR may involve a post-transcriptional mechanism analogous to that of tumor suppressor genes which also bear long, uORF-containing, 5'-UTRs, or through interactions with RNA-binding proteins.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 5' Flanking Region / genetics*
  • Abscisic Acid / pharmacology
  • Amino Acid Sequence
  • Arabidopsis / embryology
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / genetics*
  • Base Sequence
  • Darkness
  • Gene Expression Regulation, Developmental / drug effects
  • Gene Expression Regulation, Developmental / radiation effects
  • Gene Expression Regulation, Plant / drug effects
  • Gene Expression Regulation, Plant / radiation effects
  • Glucuronidase / genetics
  • Glucuronidase / metabolism
  • Green Fluorescent Proteins
  • Light
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Molecular Sequence Data
  • Mutation
  • Plant Growth Regulators / pharmacology
  • Plant Leaves / genetics
  • Plant Leaves / growth & development
  • Plant Roots / genetics
  • Plant Roots / growth & development
  • Plants, Genetically Modified
  • Promoter Regions, Genetic / genetics*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Regulatory Sequences, Nucleic Acid / genetics
  • Seeds / genetics
  • Seeds / growth & development
  • Transcription Factors

Substances

  • ABI3 protein, Arabidopsis
  • Arabidopsis Proteins
  • Luminescent Proteins
  • Plant Growth Regulators
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Green Fluorescent Proteins
  • Abscisic Acid
  • Glucuronidase