Isolation and characterization of sucrose phosphate synthase promoter from cotton (Gossypium hirsutum L.)

Abstract

Cotton fiber genes and promoters are of great importance in understanding fiber development mechanism as well as for improvement of fiber. Sucrose phosphate synthase gene (SPS) (insert abbreviation of gene)has found to express at higher rate in developing cotton fibers. It is an important enzyme that have major role in sucrose as well as cellulose synthesis. Upstream region of a SPS gene from cotton was retrieved through HTGS database and analyzed using bioinformatics tools. Sequence analysis identified various regulatory motifs including light, drought, heat responsiveness and MYB binding sites in the promoter. The SPS promoter was isolated from cotton genomic DNA (using what method) and fused to β-glucuronidase (GUS) gene in a plant expression vector. Transient GUS expression analysis in various cotton tissues showed that promoter was active in the fiber tissues. Full length 2 kb SPS promoter showed high expression in fibers during elongation and secondary cell wall synthesis stage. A 1.5 kb deletion fragment showed reduced expression in fibers. Our results suggest that cotton SPS promoter may be used to express genes specifically in fiber cells for improvement of cotton fiber quality traits.