Journal of Cell Science, Vol 99, 545-555, Copyright © 1975 by Company of Biologists

Submitted on February 25, 1991
Accepted on April 17, 1991

The organic anion transport inhibitor, probenecid, inhibits the transport of Lucifer Yellow at the plasma membrane and the tonoplast in suspensioncultured plant cells

¹ School of Biological & Molecular Sciences, Oxford Polytechnic, Gipsy Lane, Headington, Oxford 0X3 OBP, UK
² Department of Plant Sciences, Oxford University, South Parks Rd, Oxford 0X1 3RA, UK

Author for correspondence and reprints

In this paper we report on the uptake of the membrane-impermeant fluorescent probe Lucifer Yellow CH (LY-CH) into the vacuolar system of plant cell suspension cultures. LY-CH is internalised into vacuoles of maize cells at a faster ‘rate’ than carrot cells and in each case, the probe is also trapped at the cell wall. In the presence of the uricosuric drug probenecid, the vacuolar uptake of LY-CH by carrot and maize cells is inhibited and in some cells internalisation of probe is blocked at the plasma membrane. In electroporated carrot cells, LY-CH is sequestered slowly from the cytoplasm into vacuoles by a probenecid-inhibitable transport process. These results are compared with the effects of probenecid on the sequestration of LY-CH from the cytoplasm into the lysosomal system of fibroblasts. In view of the above findings and recent evidence for the putative uptake of LY-CH by fluid-phase endocytosis in plant cells, the possibility that LY-CH is transported across plant membranes via probenecidinhibitable organic anion transporters is discussed

Key words: endocytosis, electroporation, Lucifer Yellow CH, probenecid, plant cell suspension cultures

Submitted on February 25, 1991
Accepted on April 17, 1991