Figure 4.

The TSS-1 and TSS-2 promoters direct expression of the GUS reporter gene in transgenic tobacco plants. Full-length promoter and 5′-deletion constructs were prepared by fusing the indicated promoter fragments to the GUS reporter gene in the pBI101 vector and engineering these gene fusions into transgenic tobacco via standard Agrobacterium tumefaciens-mediated transformation. Promoter length designations refer to the 5′-end point of a construct relative to the translation start site at +1. R₁ seeds were germinated in the presence of kanamycin, and only 30-d-old plantlets able to grow on kanamycin for the first 15 d were evaluated quantitatively (A) or qualitatively (B) for GUS activity. The values presented in A represent the averaged data for a minimum of 10 independent transgenic lines for each construct. Representative transgenic plants harboring the 1.4-kb TSS1 or 1.2-kb TSS2 promoter-GUS reporter constructs were stained histochemically for GUS expression for 48 h. Error bars in A represent the sds, whereas the inset bar in B represents 1 cm.