ThMYC4E, candidate Blue aleurone 1 gene controlling the associated trait in Triticum aestivum

Abstract

Blue aleurone is a useful and interesting trait in common wheat that was derived from related species. Here, transcriptomes of blue and white aleurone were compared for isolating Blue aleurone 1 (Ba1) transferred from Thinopyrum ponticum. In the genes involved in anthocyanin biosynthesis, only a basic helix-loop-helix (bHLH) transcription factor, ThMYC4E, had a higher transcript level in blue aleurone phenotype, and was homologous to the genes on chromosome 4 of Triticum aestivum. ThMYC4E carried the characteristic domains (bHLH-MYC_N, HLH and ACT-like) of a bHLH transcription factor, and clustered with genes regulating anthocyanin biosynthesis upon phylogenetic analysis. The over-expression of ThMYC4E regulated anthocyanin biosynthesis with the coexpression of the MYB transcription factor ZmC1 from maize. ThMYC4E existed in the genomes of the addition, substitution and near isogenic lines with the blue aleurone trait derived from Th. ponticum, and could not be detected in any germplasm of T. urartu, T. monococcum, T. turgidum, Aegilops tauschii or T. aestivum, with white aleurone. These results suggested that ThMYC4E was candidate Ba1 gene controlling the blue aleurone trait in T. aestivum genotypes carrying Th. ponticum introgression. The ThMYC4E isolation aids in better understanding the genetic mechanisms of the blue aleurone trait and in its more effective use during wheat breeding.

Overexpression of ThMYC4E Enhances Anthocyanin Biosynthesis in Common Wheat

“…Specific primers with the adapters, ThMYC4E-pLGY02F and ThMYC4E-pLGY02R, were designed to amplify the target gene ThMYC4E from the construct pBRACT214-ThMYC4E [31]. The amplified fragments and PLGY-02 vectors were double-digested with Kpn1 and Spe1, respectively.…”

“…The bHLH transcription factor ThMYC4E has been inferred to be the candidate gene (Ba1) controlling the blue aleurone trait in T. aestivum genotypes carrying Th. ponticum introgression [31]. Although these genes have been speculated to control corresponding traits, overexpression of these major genes in common wheat has not been carried out to date, because of the difficulties in transforming wheat.…”

“…In this manuscript, ThMYC4E, the candidate major gene controlling the blue grain trait from Th. Ponticum [31], was transformed into common wheat using Agrobacterium. A series of transgenic lines were obtained to evaluate the function of bHLH in regulating anthocyanin biosynthesis and its roles in the formation of the traits related to anthocyanin biosynthesis in common wheat.…”

Marker-Assisted Development of a Blue-Grained Substitution Line Carrying the Thinopyrum ponticum Chromosome 4Th(4D) in the Spring Bread Wheat Saratovskaya 29 Background

“…ponticum Ba1 gene to the 4ThL-6 bin with FL 0.75-0.89. With the use of comparative RNA-seq analysis of blue-and white-grained wheat genotypes, the ThMyc4E gene was isolated and functionally verified as a candidate gene for Ba1 [18]. It encodes a bHLH transcription factor, regulating anthocyanin synthesis in the aleurone layer of grain.…”

“…Electropherogram of PCR products obtained using primers for the microsatellite locus Xgwm1397 on DNA of cv. Saratovskaya 29 (lane 1), Meropa (2), and blue-grained BC7F3 heterozygous(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) and homozygous(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) descendants of the selected plants from BC7F2 (b).…”