Effect of methyl decanoate upon the ultrastructure of plant cells.

Electron microscope studies of immature Chrysanthemum morifolium tissue dipped in Tween 20 emulsions of methyl decanoate indicate that the first ultrastructural effect of this pruning agent upon living cells is that of membrane disruption. The timetable of membrane destruction correlates well with the visual onset of browning or shoot destruction following foliar sprays of this emulsion. Vesicles form within the nucleus within 1 min of exposure to the emulsion. The outer limiting membrane of the nucleus breaks apart with a concurrent disappearance of endoplasmic reticulum and appearance of cytoplasmic vesicles. By 14 min the mitochondrial membrane and to a lesser degree the chloroplast membranes are breaking down. At 21 min the grana within the chloroplast, the tonoplast, and the plasmalemma membranes are destroyed. Further studies show that anthocyanin leaks from the vacuoles of red-cabbage leaf tissue after 5-min exposure to methyl decanoate emulsion and that red-onion epidermal cells undergo abnormal c...