TREATMENT OF A SINGLE PLANT-CELL WITH CHEMICALS

A technique to treat a single plant cell with chemicals was devised us ing gel beads and epidermal cells of barley coleoptile. Acridine orang e (a fluorescent dye) and cytochalasin A (an inhibitor of cytoplasmic streaming) were separately infiltrated into gel beads that were then i ndividually transferred onto a single cell of the coleoptile using a m icromanipulator. Coleoptile cells on which a gel bead infiltrated with acridine orange had been placed gave a characteristic greenish fluore scence when observed with a fluorescence microscope 24 h after the ons et of incubation. These results indicate that acridine orange diffused from the gel bead and permeated into the coleoptile cell. When coleop tile cells were treated with gel beads infiltrated with cytochalasin A , cytoplasmic streaming ceased in more than 90% of the cells by 6 h af ter the onset of treatment. These results demonstrate that cytochalasi n A diffused from the gel bead and permeated into the symplast of the target cells. The technique could be applied to test physiological eff ects of fungal products on a single plant cell.