A Database for Triticeae and Avena
USDA-ARS WESTERN REGIONAL RESEARCH CENTER
Wheat Biotechnology and Wheat Genetic Engineering Groups,
800 Buchanan St., Albany, CA 94710, USA.
Our laboratory's interests have expanded, along with the number
of personnel. Although still maintaining our work in elucidating
the mechanisms of dough viscoelasticity, we also are part of a
large intramural project seeking to markedly expand the genomic
database of expressed sequences in wheat under varying conditions
and in various tissues.
The director of these projects is Olin D.
Anderson. Personnel involved in the projects are Gerry Lazo, Vickie
Carollo, Michael Gitt, Shiaoman Chao, Cheryl Hsia, Phyllis Han,
Carrie Rausch, Ruthellen Miller, Yurah Kang, Cheryl Seaton, Jason
Chang, Jenny Tong, Debbie Laudencia Chincuango, and Ed Butler.
Because the genome of hexaploid bread wheat
is magnitudes larger than the human genome, we have began the
genomics study with the expressed portion of the genome first.
Several cDNA libraries from different tissues and from the same
tissue under different conditions have been prepared and are now
in the process of high-throughput sequencing using PE Applied
Biosystems ABI 3700 and Beckmann CEQ2000 sequencers. This large
quantity of sequences is then processed to a usable form by software
being refined in the laboratory and will appear in the GrainGenes
The laboratory maintains the GrainGenes
database (http://wheat.pw.usda.gov), which permits web-based homology
searches to wheat, oat, barley, rice, sugarcane, maize, and noncereals.
We are continuing service to the cereal
research community by banking and partially characterizing all
clones that we and others provide. We also make these clones available
for the entire research community. This past year, we distributed
over 1,500 individual clones from the probe repository. Clones
can be ordered by contacting email@example.com.
We are pursuing several strategies for increasing
the amount of lysine in wheat seed proteins, with the aim of increasing
the nutritive value of this major source of dietary protein both
for humans and farm animals for whom lysine is an essential amino
acid. Preliminary tests will assess effects of the changes on
We have engineered a synthetic version of
the high molecular weight glutenin, Dx5, which is highly expressed
in E. coli. We also have generated several mutations in this gene,
targeting amino acids that are hypothesized to play a central
role in intermolecular interactions in the gluten polymer. After
expressing these mutants in a bacterial expression system, we
can study their effect on mixing parameters of dough and thereby
learn about interactions responsible for dough viscoelasticity.
We have sequenced upstream and downstream
regions of the genes encoding Ax, Ay, Bx, By, Dx, and Dy HMW glutenins.
These flanking sequences provide information on the evolution
of the various glutenin alleles and suggest new control sequences
that could prove useful in future transgenic work. We also have
isolated several gliadin genes and have discovered new classes