Progress toward the production of transgenic grapevines by Agrobacterium-mediated transformation

Grape possesses the basic prerequisites for Agrobacterium-mediated transformation it is a host for Agrobacterium and plant regeneration can be induced from cultured grape explants. Leaf explants were cocultivated with disarmed Agrobacterium vectors carrying kanamycin resistance and GUS genes and cultured on shoot-inducing medium containing kanamycin. After 21 d, intense and sharply-defined blue regions were observed, including some blue organized meristematic structures, consistent with plant-driven GUS gene expression. No GUS activity was detected in control explants. Among single leaf tips excised from over 200 regenerated shoots, one was GUS positive. The recovery of transgenic shoots might be improved by increasing the frequency or modifying the site of transformation and/or regeneration.