Characterization of an expressed Triticum monococcum Glu-A1y gene containing a premature termination codon in its C-terminal coding region

Abstract

Premature termination codons (PTCs) are an important reason for the silence of highmolecular-weight glutenin subunits in Triticum species. Although the Glu-A1y gene is generally silent in common wheat, we here isolated an expressed Glu-A1y gene containing a PTC, named 1Ay8.3, from Triticum monococcum ssp. monococcum (A m A m , 2n = 2x = 14). Despite the presence of a PTC (TAG) at base pair positions 1879-1881 in the C-terminal coding region, this did not obviously affect 1Ay8.3 expression in seeds. This was demonstrated by the fact that when the PTC TAG of 1Ay8.3 was mutated to the CAG codon, the mutant in Escherichia coli bacterial cells expressed the same subunit as in the seeds. However, in E. coli, 1Ay8.3 containing the PTC expressed a truncated protein with faster electrophoretic mobility than that in seeds, suggesting that PTC translation termination suppression probably occurs in vivo (seeds) but not in vitro (E. coli). This may represent one of only a few reports on the PTC termination suppression phenomenon in genes.

Genetic Basis of Gluten Aggregation Properties in Wheat (Triticum aestivum L.) Dissected by QTL Mapping of GlutoPeak Parameters

“…A premature termination codon (PTC) mutation in TaD3-354 was detected between Luozhen No. 1 and Zhengyumai 9987 (Figure 4), which were reported as an important cause for the silence of high-molecular-weight glutenin subunits in Triticum species (Chen et al, 2018). TaD3-354 was anchored in the QTL cluster on chromosome 1DS by genotyping the RIL population with KASP markers designed based on the SNPs in TaD3-354 and TraesCS1D02G009900.…”

Allelic Variation of High-Molecular-Weight Glutenin Genes in <i>Triticum</i> Species and Triticale (× <i>Triticosecale</i> Wittmack)

“…A wider variation for the Glu-A1x was detected [13][14][15]. The spectrum of A1y-subunits was extended by 1Ay8* and 1Ay12* [16] and 1Ay8.2 and 1Ay8.3 [17,18]. At present, the A genome of T. monococcum (incl.…”