Molecular and General Genetics MGG

, Volume 253, Issue 5, pp 599–608

Structure, hormonal regulation, and chromosomal location of genes encoding barley (1å4)-β-xylan endohydrolases

  • M. Banik
  • C.-D. Li
  • P. Langridge
  • G. B. Fincher
ORIGINAL PAPER

DOI: 10.1007/s004380050362

Cite this article as:
Banik, M., Li, C., Langridge, P. et al. Mol Gen Genet (1997) 253: 599. doi:10.1007/s004380050362

Abstract

A gene encoding (1→4)-β-xylan xylanohydrolase (EC 3.2.1.8) isoenzyme X-I has been isolated from a barley genomic library and the nucleotide sequence of a 2704-bp fragment defined. The gene contains a single intron of 91 bp in the coding region of the mature enzyme and additional introns may be present in the 5′-untranslated region. Expression of the xylanase gene is restricted to the aleurone layer of germinated grain, where the phytohormone gibberellic acid induces both transcriptional activity of the gene and the secretion of active enzyme from the layers. Abscisic acid abolishes the gibberellic acid induction of xylanase gene expression. The hormonal responses are consistent with the presence of promoter sequences, all of which are within 150 bp of the putative transcription start site, that have been implicated as cis-acting elements within gibberellic acid response complexes in plant genes. The elements include a pyrimidine box, CTCTTTCC, together with TAACGAC and TATCCAT boxes. Three genes encode (1→4)-β-xylanase isoenzymes in barley and these have been mapped on the barley genome using two doubled haploid populations and seven wheat-barley addition lines. The three xylanase genes are closely linked on the long arm of chromosome 7 (5H). No recombination was detected between the genes in 234 doubled haploid lines. The genes are flanked by the RFLP markers CDO506 on the proximal side and PSR370 at the distal end.

Key words Aleurone layer  Gene mapping Gibberellic acid  Plant xylanases   Tissue-specific regulation

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • M. Banik
    • 1
  • C.-D. Li
    • 1
  • P. Langridge
    • 1
  • G. B. Fincher
    • 1
  1. 1.Department of Plant Science, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, AustraliaAU