Function Deletion Analysis of Light-induced Gacab Promoter from Gossypium arboreum in Transgenic Tobacco

Abstract

The 1009 bp promoter sequence of a light-induced gene, cab, has been cloned from the Gossypium arboreum in an earlier study. This gene encodes the chlorophyll a/b binding protein, which belongs to a class of light-inducible proteins. For designing a minimal length light-inducible Gacab promoter, the full-length Gacab P and the 5′ truncations of 197, 504, and 779 bp in length were fused with gus ( uid A) gene and ligated into plant expression vectors. All the constructs were transformed into Nicotiana tabacum variety NC89 using Agrobacterium-mediated transformation method. Seeds from the T 1 generation of transgenic tobacco were germinated and grown in either light or dark condition. A GUS histochemical assay showed that only the full-length Gacab promoter was light inducible and expressed in a tissue-specific manner. Promoter activities were quantified by GUS quantity analysis, and the promoter fragment from −504 to −1 bp had the highest activity, which was 0.6-fold higher than that of the CaMV35S promoter.