The V-ATPase inhibitors concanamycin A and bafilomycin A lead to Golgi swelling in tobacco BY-2 cells.

Concanamycin A and bafilomycin A are well-known inhibitors of V-ATPase activity. It is known that they interfere with intracellular protein trafficking in both animal and plant cells, but a cellular target for their action in plant cells has not been defined. Here we show that treatment with these inhibitors leads to a massive vacuolation of the Golgi apparatus. The effect is similar, but not identical, to that previously described for the Na+/K+ ionophores and is reversible after washing.