Effect of ethylene on Agrobacterium tumefaciens-mediated gene transfer to melon

The effect of ethylene on gene transfer mediated by an Agrobacterium tumefaciens harbouring a binary vector with the β-glucuronidase (uidA) gene was investigated in melon, Cucumis melo L. Explants excised from melon cotyledons produced ethylene, the production of which was increased by the addition of 1-aminocyclopropane-1-carboxylic acid (ACC, 20 or 200 μM), and inhibited by the addition of aminoethoxy-vinylglycin (AVG, 10 μM). Agrobacterium inoculation of explants increased ethylene production, while application of AVG during inoculation reduced it. After 4 days of co-cultivation with Agrobacterium, gene transfer in the explants was assayed by transient uidA expression. Application of ACC to the co-cultivation medium reduced Agrobacterium-mediated gene transfer to explants and that of AVG increased it. These results suggest that ethylene effects the A. tumefaciens-mediated gene transfer to the explants excised from melon cotyledons, and the efficiency of Agrobacterium-mediated gene transfer can be improved by inhibiting ethylene production from the explants.