Molecular characterization of novel LMW-i glutenin subunit genes from Triticum urartu Thum. ex Gandil.

Abstract

A high level of genetic diversity was found in LMW-i genes from Triticum urartu, resulting in detection of 11 novel alleles. The variability detected could affect gluten quality. Low-molecular weight glutenin subunits are important in determining the viscoelastic properties of wheat dough. Triticum urartu Thum. ex Gandil., which is related to the A genome of polyploid wheat, has been shown as a good source of variation for these subunits. The present study evaluated the variability of LMW-i genes in this species. High polymorphism was found in the sequences analysed and resulted in the detection of 11 novel alleles, classified into two sets (Group-I and -II) showing unique SNPs and InDels. Both groups were associated with Glu-A3-1 genes from common wheat. In general, deduced proteins from Group-II genes possessed a higher proportion of glutamine and proline, which has been previously suggested to be related with good quality. Moreover, there were other changes compared to common wheat. This novel variation could affect dough quality. Additional epitopes for celiac disease were also detected, suggesting that these subunits could be highly reactive. The results showed that T. urartu could be an important source of genetic variability for LMW-i genes that could enlarge the genetic pool of modern wheat.