AGROBACTERIUM-MEDIATED GENETIC-TRANSFORMATION OF GRAPEVINE SOMATIC EMBRYOS AND REGENERATION OF TRANSGENIC PLANTS EXPRESSING THE COAT PROTEIN OF GRAPEVINE CHROME MOSAIC NEPOVIRUS (GCMV)

Transgenic plants of the grapevine rootstock 110 Richter (Vitis Berlandieri x V. rupestris) were regenerated from embryogenic cultures co-cultivated with a disarmed LBA4404 strain of Agrobacterium tumefaciens harbouring a binary vector which contained chimeric genes for hygromycin resistance (HPT), kanamycin resistance (NPT II), beta-glucuronidase (GUS) and the coat protein of grapevine chrome mosaic nepovirus (GCMV-CP). The best rate of transformation was obtained by selection of putative embryogenic tissues on 16 mu g/ml hygromycin. GUS activity was readily observed in somatic embryos and in transformed plants derived from them. Southern blot analysis demonstrated the integration of the T-DNA sequence into the plant genome. High levels of GCMV-CP expression were detected by ELISA in somatic embryos, leaves and roots df the transformed plants, and confirmed-by Western blot.