EFFECTS OF INHIBITORS ON PHENOCRITICAL EVENTS OF IN-VITRO SHOOT ORGANOGENESIS IN TOBACCO THIN CELL-LAYERS

Phenocritical disruption of in vitro shoot regeneration in tobacco (Ni cotiana tabacum cv. Samsun) thin cell layers (TCL) was assessed using four exogenously supplied inhibitors. Specifically, the inhibitors wer e used to disrupt the events associated with the differentiation and d etermination of adventitious shoots in pre-induced tobacco TCL explant s in a phenocritical manner. Shoot determination and development exhib ited the greatest sensitivity to all four inhibitors (cycloheximide, r ibose, thymidine and triiodobenzoic acid) between days 0 and 4 followi ng induction. Therefore, protein synthesis, energy stores, DNA synthes is and auxin transport are all very important in the early stages of s hoot meristem determination. Knowledge of phenocritical events in de n ovo shoot organogenesis in tobacco TCL explants will be helpful in iso lating and characterizing genes involved in the determination and deve lopment of such meristems.