Isolation and characterization of cDNAs encoding oat 12S globulin mRNAs

Area of Science:

• Plant molecular biology
• Seed storage proteins
• Genomics

Background:

• Oat (Avena sativa) seed storage proteins are crucial for plant development and nutrition.
• Globulins constitute a significant fraction of oat seed proteins.
• Understanding the genetic basis of globulin synthesis is essential for crop improvement.

Purpose of the Study:

• To isolate and characterize cDNA clones encoding oat globulins.
• To investigate the gene family structure of oat globulins.
• To determine the sequence and precursor structure of oat globulins.

Main Methods:

• Construction of a cDNA library from developing oat seeds.
• Identification of globulin cDNA clones using synthetic oligonucleotide probes.
• Restriction enzyme mapping and cross-hybridization analysis of clones.
• Nucleotide sequencing of a representative globulin cDNA clone.

Main Results:

• Four distinct classes of oat globulin cDNA clones were identified.
• Oat globulin genes belong to a multigene family, as indicated by hybridization to multiple genomic DNA fragments.
• Sequence analysis confirmed the identity of an oat globulin and revealed its synthesis as a precursor.
• The basic polypeptide showed homology to other 11S seed globulin basic polypeptides.

Conclusions:

• Oat globulins are synthesized as precursors, analogous to legume 11S storage globulins.
• The genes encoding oat globulins are organized in a multigene family.
• This research provides foundational insights into the molecular characterization of oat seed storage proteins.