EARLY CELLULAR EVENTS DURING INDUCTION OF CARROT EXPLANTS WITH 2,4-D

The cellular events occurring in carrot hypocotyl explants during long -term and pulse treatment with 2,4-D were followed using different tec hniques (light and transmission electron microscopy, flow cytometry, P CNA staining). Different morphogenetic pathways were induced under the various experimental conditions. Nevertheless, in the explants the ac tivated cells were the same (provascular cells) and they showed very s imilar structural and ultrastructural changes. The long-term treatment with 2,4-D induced rapid re-activation of the cell cycle.