Percentage of plants expressing GFP after vacuum infiltration of germinated pea seeds with a mixture of Agrobacterium GV3101 strains carrying binary plasmid pCAPE2-GFP and pCAPE-1 respectively. (a) Frequency of transformants with variation of length of vacuum exposure. Series 1, 2, 3 and 4: peas seeds were subjected to vacuum for 1 min, 5 min, 10 min and 15 min. (b) The frequency of GFP expressing plants with increasing vacuum pressure (c) Frequency of GFP expressing plants with wounded and non-wounded roots. (d) The frequency of GFP expressing plants upon treatment with different bacterium suspension densities.