“…In the present study, we investigated the effect of acetylcholine and its breakdown products, choline and acetate, as well as neostigmine (Nst), an inhibitor of ACh breakdown, on morphogenic behaviour of leaf explants of tomato cultured on Murashige and Skoog's (MS) medium (Murashige and Skoog, 1962). Tomato was chosen as an experimental system because (a) its morphogenic behaviour in vitro is well known (Sink and Reynolds, 1986), and (b) the tomato family, Solanaceae contains ACh, the ACh hydrolysing enzyme acetylcholinesterase (AChE) as well as several alkaloids that are known to affect ACh system in animals (Roshchina, 2001).…”