Plant Molecular Biology

, Volume 41, Issue 3, pp 403–414

Evidence for factors regulating transfer cell-specific expression in maize endosperm

  • Gregorio Hueros
  • Joaquin Royo
  • Monika Maitz
  • Francesco Salamini
  • Richard D. Thompson
Article

DOI: 10.1023/A:1006331707605

Cite this article as:
Hueros, G., Royo, J., Maitz, M. et al. Plant Mol Biol (1999) 41: 403. doi:10.1023/A:1006331707605

Abstract

In maize, a layer of basal endosperm cells adjacent to the pedicel is modified for a function in solute transfer. Three genes specifically expressed in this region, termed the basal endosperm transfer layer (BETL-2 to -4), were isolated by differential hybridization. BETL-2 to -4 are coordinately expressed in early and mid-term endosperm development, but are absent at later stages. BETL-2 to -4 coding sequences all predict small (<100 amino acids), secreted, cysteine-rich polypeptides which lack close relatives in current database accessions. BETL-3 and BETL-1 display some sequence similarities with each other and to plant defensins. BETL-2 to -4 promoter regions were isolated and compared, revealing the presence of a promoter-proximal microsatellite repeat as the most highly conserved sequence element in each sequence. Electrophoretic mobility shift assays (EMSA) showed that specific BETL-2 to -4 promoter fragments competed for binding to the same DNA-binding activity in nuclear extracts prepared from maize endosperm. Although BETL-2 to -4 are only expressed in basal endosperm cells, the DNA-binding activities detected were of two types: distal endosperm-specific, or present in both basal and distal endosperm extracts. On the basis of these findings, a model to account for the coordinate regulation of BETL genes in endosperm cells is proposed.

BETLendospermmaizepromotertransfer cell

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Gregorio Hueros
    • 1
  • Joaquin Royo
    • 2
  • Monika Maitz
    • 1
  • Francesco Salamini
    • 1
  • Richard D. Thompson
    • 1
  1. 1.MPI für Züchtungsforschung, Carl-von-Linné Weg 10KölnGermany
  2. 2.Dpto. Biología Celular y GeneticaUniversity AlcalaAlcala de HenaresSpain