Abstract
Several reports have been shown that plants have the endocytotic pathway, although the details are still obscure. To clarify the mechanisms of endocytosis, we investigated endocytosis of BY-2 cells by visualizing endosomes with a fluorescent dye, FM4-64. When BY-2 cells were transferred to sucrose-starved or non-starved condition, FM4-64 was first bound to plasma membranes, then entered to small vesicles and finally transported to vacuoles. When BY-2 cells were treated with an inhibitor of papain family proteases, E64d, under sucrose-starved condition, FM4-64 was not transported to vacuoles. Instead, many vesicles with FM4-64 were accumulated in the cytosol. When BY-2 cells were treated with E64d under non-starved condition, no vesicles with FM4-64 were accumulated. These results suggest that papain family proteases were involved in endocytosis when BY-2 cells were starved.
