TRANSFORMATION OF CHICORY AND EXPRESSION OF THE BACTERIAL UIDA AND NPTLL GENES IN THE TRANSGENIC REGENERANTS

Transgenic chicory plants were obtained from different explants co-cul tured with Agrobacterium tumefaciens. Among tap-root, leaf and cotyled onary tissues, etiolated cotyledons showed the greatest competence for transformation. The Agrobacterium strains used contained either pGSGL UC1 or pTDE4 as a vector which carry both the neomycin phosphotransfer ase ii gene (nptII) for kanamycin resistance and beta-glucuronidase ge ne (uidA) under the control of different promoters. Transformation was confirmed by NPTII enzymatic assay, histochemical analysis of GUS act ivity and DNA hybridization. Transgenic plants expressed both marker g enes in root and shoot tissues. In leaves, GUS activity was expressed in all tissue types, whatever the nature of the promoter. Nevertheless , variable heterogeneous patterns of expression were observed in the d ifferent root tissues. Differential expression of the GUS fusions cont rolled by the dual Tn or the CaMV 35S promoters are discussed.