Heteroalleles in Common Wheat: Multiple Differences between Allelic Variants of the Gli-B1 Locus

Int J Mol Sci. 2021 Feb 12;22(4):1832. doi: 10.3390/ijms22041832.

Abstract

The Gli-B1-encoded γ-gliadins and non-coding γ-gliadin DNA sequences for 15 different alleles of common wheat have been compared using seven tests: electrophoretic mobility (EM) and molecular weight (MW) of the encoded major γ-gliadin, restriction fragment length polymorphism patterns (RFLPs) (three different markers), Gli-B1-γ-gliadin-pseudogene known SNP markers (Single nucleotide polymorphisms) and sequencing the pseudogene GAG56B. It was discovered that encoded γ-gliadins, with contrasting EM, had similar MWs. However, seven allelic variants (designated from I to VII) differed among them in the other six tests: I (alleles Gli-B1i, k, m, o), II (Gli-B1n, q, s), III (Gli-B1b), IV (Gli-B1e, f, g), V (Gli-B1h), VI (Gli-B1d) and VII (Gli-B1a). Allele Gli-B1c (variant VIII) was identical to the alleles from group IV in four of the tests. Some tests might show a fine difference between alleles belonging to the same variant. Our results attest in favor of the independent origin of at least seven variants at the Gli-B1 locus that might originate from deeply diverged genotypes of the donor(s) of the B genome in hexaploid wheat and therefore might be called "heteroallelic". The donor's particularities at the Gli-B1 locus might be conserved since that time and decisively contribute to the current high genetic diversity of common wheat.

Keywords: APAGE; DNA sequencing; Gli-B1; PCR; Triticum aestivum; γ-gliadin polymorphism.

MeSH terms

  • Alleles*
  • Genes, Plant*
  • Genetic Loci*
  • Gliadin / genetics*
  • Pseudogenes*
  • Triticum / genetics*

Substances

  • Gliadin