The promoter from tomato sucrose synthase gene TOMSSF drives stamen-specific gene expression in Chrysanthemum

Anther-specific promoters have been extensively studied in terms of the genetic engineering of male-sterile plants. Here, we fused the 5′ upstream promoter regions of a sucrose synthase gene from tomato (TOMSSF) to the β-glucuronidase (GUS) gene and used the construct to transform Chrysanthemum plants. Histochemical analysis of two transformants showed high GUS activity in ray florets and tubular florets. Analysis of the staining pattern in these florets reveled that staining was stamen-specific. GUS gene expression was highest in the stamen and remained at a steady-state level throughout the experiment. These results suggest that the TOMSSF promoter has high activity in the stamen of tubular florets and would be useful as a high stamen-specific promoter in Chrysanthemum.