棉 花 学 报 Cotton Science 2007，19(6)：431-435
Expression Pattern of a Recombinant Phloem-specific Promoter from Pumpkin in Transgenic Cotton Plants Abstract：The plant expression vector pBII2 was constructed on the basis of pBI121，which contains the neomycin phosphotransferase gene (NPT II) expression cassette and the β-glucuronidase (Gus ) gene driven by a recombinant pumpkin phloem-specific promoter (dENP). Cotton embyogenesis calli from aseptically cultured cv. Coker 312 plants were transformed with pBII2 and pBI121 mediated by Agrobacterium tumefaciens ，respectively. 243 independent transformants of kanamycin resistant cotton plants were regenerated. PCR and Southern blot analyses confirmed that the Gus gene had been integrated into the plant genome in 172 out of all independently transformed cotton plants. Integration of the transgene varied from one to over two estimated copies in the analyzed plants. Gus expression in the transgenic plants was either constitutive or tissue specific，depending on the nature of the promoter used. Results from histochemical staining confirmed that the Gus activity was specifically localized in phloem tissue of the transgenic plants if dENP promoter drives the Gus gene. The average Gus activity in pBII2 transgenic plants had no significant difference compared with that driven by CaMV35S promoter.
|