Expression Pattern of the Alpha-Kafirin Promoter Coupled with a Signal Peptide fromSorghum bicolorL. Moench

[摘要] Regulatory sequences with endosperm specificity are essential for foreign gene expression in the desired tissue for both grain quality improvement and molecular pharming. In this study, promoters of seed storageα-kafirin genes coupled with signal sequence (ss) were isolated fromSorghum bicolorL. Moench genomic DNA by PCR. Theα-kafirin promoter (α-kaf) contains endosperm specificity-determining motifs, prolamin-box, the O2-box 1, CATC, and TATA boxes required forα-kafirin gene expression in sorghum seeds. The constructs pMB-Ubi-gfpand pMB-kaf-gfpwere microprojectile bombarded into various sorghum and sweet corn explants. GFP expression was detected on all explants using the Ubi promoter but only in seeds for theα-kaf promoter. This shows that theα-kaf promoter isolated was functional and demonstrated seed-specific GFP expression. The constructs pMB-Ubi-ss-gfpand pMB-kaf-ss-gfpwere also bombarded into the same explants. Detection of GFP expression showed that the signal peptide (SP)::GFP fusion can assemble and fold properly, preserving the fluorescent properties of GFP.

[学科分类] 基础医学