Identifying -Acting Elements Associated with the High Activity and Endosperm Specificity of the Promoters of Genes Encoding Low-Molecular-Weight Glutenin Subunits in Common Wheat ().

Low-molecular-weight glutenin subunits (LMW-GSs) associated with bread-baking quality and flour nutrient quality accumulate in endosperms of common wheat and related species. However, the mechanism underlying the expression regulation of genes encoding LMW-GSs has not been fully elucidated. In this study, we identified and , which are highly and weakly expressed, respectively, via the analysis of RNA-sequencing data of Chinese Spring wheat and wheat transgenic lines transformed with 5' deletion promoter fragments and fusion constructs. The 605-bp fragment upstream of the start codon could drive high levels of expression in the endosperm. The truncated endosperm box located at the -300 site resulted in the loss of promoter activity, and a single-nucleotide polymorphism on the GCN4 motif was closely related to the expression of . TCT and TGACG motifs, as well as the others located on the 5' distal end, might also be involved in the transcription regulation of . In transgenic lines, fusion proteins of LMW-GS and GUS were deposited into protein bodies. Our findings provide new insights into the mechanism underlying the transcription regulation of and will contribute to the development of wheat endosperm as a bioreactor for the production of nutraceuticals, antibodies, vaccines, and medicinal proteins.