title: Strong seed-specific protein expression from the Vigna radiata storage protein 8SGα promoter in transgenic Arabidopsis seeds.
abstract: Vigna radiata (mung bean) is an important crop plant and is a major protein source in developing countries. Mung bean 8S globulins constitute nearly 90% of total seed storage protein and consist of three subunits designated as 8SGα, 8SGα' and 8SGβ. The 5'-flanking sequences of 8SGα' has been reported to confer high expression in transgenic Arabidopsis seeds. In this study, a 472-bp 5'-flanking sequence of 8SGα was identified by genome walking. Computational analysis subsequently revealed the presence of numerous putative seed-specific cis-elements within. The 8SGα promoter was then fused to the gene encoding β-glucuronidase (GUS) to create a reporter construct for Arabidopsis thaliana transformation. The spatial and temporal expression of 8SGα∷GUS, as investigated using GUS histochemical assays, showed GUS expression exclusively in transgenic Arabidopsis seeds. Quantitative GUS assays revealed that the 8SGα promoter showed 2- to 4-fold higher activity than the Cauliflower Mosaic Virus (CaMV) 35S promoter. This study has identified a seed-specific promoter of high promoter strength, which is potentially useful for directing foreign protein expression in seed bioreactors.
authors: School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors: Mo-Xian
authors: MX
authors: Chen
authors: School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors: Shu-Xiao
authors: SX
authors: Zheng
authors: College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors: Yue-Ning
authors: YN
authors: Yang
authors: College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors: Chao
authors: C
authors: Xu
authors: College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors: Jie-Sheng
authors: JS
authors: Liu
authors: College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors: Wei-Dong
authors: WD
authors: Yang
authors: School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China. Electronic address: mlchye@hkucc.hku.hk.
authors: Mee-Len
authors: ML
authors: Chye
authors: College of Life Science and Technology, Jinan University, Guangzhou 510632, China. Electronic address: thyli@jnu.edu.cn.
authors: Hong-Ye
authors: HY
authors: Li
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D016386:Chromosome Walking; D007887:Fabaceae / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018745:Genome, Plant; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D055314:Seed Storage Proteins / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D011993:Recombinant Fusion Proteins; D055314:Seed Storage Proteins; D005966:Glucuronidase
keywords: Genome-walking; Promoter; Seed-specific; Transgenic Arabidopsis; Vigna radiata; β-Glucuronidase