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 × 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), β-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 μg/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 of the transformed plants, and confirmed by Western blot.