The characterization of cDNA clones coding for wheat storage proteins

Area of Science:

• Plant molecular biology
• Genetics and genomics
• Protein biochemistry

Background:

• Wheat endosperm development involves the synthesis of storage proteins like gliadins.
• Understanding the genetic basis of gliadin diversity is crucial for wheat breeding and quality.

Purpose of the Study:

• To construct and analyze a cDNA library from developing wheat endosperm.
• To identify and characterize genes encoding gliadin-related storage proteins.
• To investigate the structural basis of gliadin diversity.

Main Methods:

• Isolation of polyadenylated (Poly(A)+) RNA from developing wheat endosperm (var. Chinese Spring).
• Construction of a complementary DNA (cDNA) library using the isolated RNA.
• Hybrid selection of messenger RNA (mRNA) followed by in vitro translation to identify specific clones.
• DNA sequencing of selected cDNA clones.
• Sequence homology analysis with known storage protein genes.

Main Results:

• A cDNA library was successfully constructed from developing wheat endosperm.
• Clones encoding alpha/beta-gliadin and gamma-gliadin related sequences were identified.
• DNA sequencing revealed homology between a wheat gliadin clone and a barley B-hordein clone.
• The identified wheat gliadin sequence contains a tandem DNA repeat.

Conclusions:

• The identified cDNA clone represents a wheat gliadin storage protein gene.
• The homology to barley B-hordein suggests conserved features in cereal storage protein evolution.
• The tandem DNA repeat is a potential mechanism contributing to the generation of diversity within wheat gliadins.