Genetic transformation of the C-3-C-4 intermediate plant, Flaveria pubescens (Asteraceae)

The dicot genus Flaveria (Asteraceae), besides species with C-3 or C-4 photosynthesis, contains taxa with a broad range of different states of transition between the two major photosynthetic types. We have developed a reproducible and efficient Agrobacterium-mediated method for the stable genetic transformation of the C-3-C-4, intermediate species F. pubescens. Fusion constructs of the reporter gene beta-glucuronidase (uidA, GUS) to several plant promoters, mainly derived from genes encoding subunits of the glycine cleavage system (gdcs), have been used to confirm the reproducibility and efficiency of the method. The stable integration of the foreign DNA has been examined by Southern analysis, kanamycin resistance, GUS enzyme activities and histochemical staining. Transformed shoots can be routinely obtained within 8-10 weeks after co-cultivation with A. tumefaciens.