# The High-Molecular-Weight Glutenin Subunits of the T. timopheevii (AuAuGG) Group

## TL;DR

This study examines glutenin subunits in a type of wheat to understand genetic variation and improve wheat properties.

## Contribution

The study identifies structural features and allelic variation of HMW-GSs in T. timopheevii subspecies.

## Key findings

- Accessions with y-type subunits at the Glu-A1 locus were found in both subspecies.
- Genes with seven cysteine residues and specific repeat motifs were confirmed in y-type genes.
- Wild and cultivated T. timopheevii can contribute to modifying HMW-GS allelic composition in wheat.

## Abstract

Polyploid wheats include a group of tetraploids known as Timopheevii (AuAuGG), which are represented by two subspecies: Triticum timopheevii ssp. timopheevii (cultivated) and Triticum timopheevii ssp. araraticum (wild). The combined use of electrophoretic (SDS-PAGE) and chromatographic (RP-HPLC) techniques carried out on high-molecular-weight glutenin subunits (HMW-GSs) permitted the association of different x- and y-type subunits to the A and G genomes and the assessment of allelic variation present at corresponding loci. The results also revealed that in both subspecies, accessions are present that possess expressed y-type subunits at the Glu-A1 locus. Genes corresponding to these subunits were amplified and amplicons corresponding to x- and y-type genes associated with the A genome were detected in all accessions, including those without expressed x- and y-type subunits. The comparison with genes of polyploid wheats confirmed the structural characteristics of typical y-type genes, with the presence of seven cysteine residues and with hexapeptide and nonapeptide repeat motifs. The identification of wild and cultivated T. timopheevii with both x- and y-type glutenin subunits at the Glu-A1 and Glu-G1 loci represents a useful source for the modification of the allelic composition of HMW-GSs in cultivated wheats with the ultimate objective of improving technological properties.