Reference "Analyses of alpha/beta-type gliadin genes from diploid and hexaploid wheats"

Reference ID

9273

Title

Analyses of alpha/beta-type gliadin genes from diploid and hexaploid wheats

Source

Gene, 1987, vol. 52, pp. 257-266

Authors (2)

Reeves-C-D

Okita-T-W

Abstract

The alpha/beta-gliadin genes isolated from both hexaploid wheat (cv. Yamhill)
and the diploid A genome progenitor Triticum urartu had remarkably similar
sequences and differ by only a few point mutations. Primer extension analysis
indicated that the transcriptional start points for individual genes in the
family cluster within a few nucleotides. Comparison of the promoter region of
several alpha/beta-gliadin and B-hordein genes reveals two conserved regions at
about -130 and -250 bp. DNA from the hexaploid cultivars, Cheyenne and Chinese
Spring, and the diploid progenitors T. urartu and Aegilops squarrosa was
analysed by Southern blotting. Restriction fragment lengths of the alpha/beta-
gliadin genes varied only slightly between the various wheats, although the
overall copy number varied significantly. A region between approx. -1700 and -
700 bp upstream from the TATA box was highly repeated in all three wheat
genomes. For the hexaploid-derived gene, over 1700 bp of sequence upstream from
the TATA box was determined, revealing an additional open reading frame between
approx. -1550 and -1250 bp relative to the gliadin TATA box. Northern blot
analysis indicated that RNA homologous to this repeated sequence family was
present only in developing seed and accumulated to a maximum at late stages of
maturation.