title: Expression of wheat high molecular weight glutenin subunit 1Bx is affected by large insertions and deletions located in the upstream flanking sequences.
abstract: To better understand the transcriptional regulation of high molecular weight glutenin subunit (HMW-GS) expression, we isolated four Glu-1Bx promoters from six wheat cultivars exhibiting diverse protein expression levels. The activities of the diverse Glu-1Bx promoters were tested and compared with β-glucuronidase (GUS) reporter fusions. Although all the full-length Glu-1Bx promoters showed endosperm-specific activities, the strongest GUS activity was observed with the 1Bx7OE promoter in both transient expression assays and stable transgenic rice lines. A 43 bp insertion in the 1Bx7OE promoter, which is absent in the 1Bx7 promoter, led to enhanced expression. Analysis of promoter deletion constructs confirmed that a 185 bp MITE (miniature inverted-repeat transposable element) in the 1Bx14 promoter had a weak positive effect on Glu-1Bx expression, and a 54 bp deletion in the 1Bx13 promoter reduced endosperm-specific activity. To investigate the effect of the 43 bp insertion in the 1Bx7OE promoter, a functional marker was developed to screen 505 Chinese varieties and 160 European varieties, and only 1Bx7-type varieties harboring the 43 bp insertion in their promoters showed similar overexpression patterns. Hence, the 1Bx7OE promoter should be important tool in crop genetic engineering as well as in molecular assisted breeding.
authors.affiliation: Key Laboratory of Crop Gene Resources and Germplasm Enhancement, Ministry of Agriculture/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China; College of Biological sciences, China Agricultural University, Beijing, China.
authors.forename: Yuke
authors.initials: Y
authors.lastname: Geng
authors.affiliation: Beijing Engineering and Technique Research Center of Hybrid Wheat, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China.
authors.forename: Binshuang
authors.initials: B
authors.lastname: Pang
authors.affiliation: Key Laboratory of Crop Gene Resources and Germplasm Enhancement, Ministry of Agriculture/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Chenyang
authors.initials: C
authors.lastname: Hao
authors.affiliation: College of Biological sciences, China Agricultural University, Beijing, China.
authors.forename: Saijun
authors.initials: S
authors.lastname: Tang
authors.affiliation: Key Laboratory of Crop Gene Resources and Germplasm Enhancement, Ministry of Agriculture/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Xueyong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Crop Gene Resources and Germplasm Enhancement, Ministry of Agriculture/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Li
mesh_terms: D001483:Base Sequence; D018506:Gene Expression Regulation, Plant; D005983:Glutens / Q000235:genetics*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D012275:Oryza / Q000235:genetics; D010802:Phylogeny; D030821:Plants, Genetically Modified / Q000235:genetics; D011401:Promoter Regions, Genetic; D021122:Protein Subunits / Q000235:genetics; D016415:Sequence Alignment; D017384:Sequence Deletion; D014908:Triticum / Q000235:genetics*
chemical_list: D021122:Protein Subunits; D005983:Glutens; C037302:glutenin