In vitro culture using nicotine and d-tubocurarine and in silico analysis depict the presence of acetylcholine receptor (AChR) in tomato (Solanum lycopersicum L.)

Acetylcholine, an established neurotransmitter, is now known to regulate several plant processes. The researchers of this current study have already reported that ACh promotes root and inhibits shoot and callus formation, demonstrating its role in differentiation and morphogenesis in tomato (Solanum lycopersicum) in vitro leaf cultures (Bamel et al. Life Sci 80:2393–2396, 2007; Plant Signal Behav 11:6, 2016). To explore the presence of nicotinic acetylcholine receptor in plant cells, the effects of nicotine and tubocurarine, the agonists and antagonists for this receptor, were also assessed and it was found that nicotine mimicked the action of acetylcholine (ACh) by promoting root formation (Bamel et al. Int Immunopharmacol 29: 231–234, 2015). In the present study, nicotine simulated ACh and reduced the shoot and callus formation. d-Tubocurarine showed antagonistic effect on shoot formation. These investigations demonstrate indirect evidence for the presence of nAChR. To confirm the existence of receptor for ACh, in silico analysis was also carried out which confirmed the possibility of LOC 101,263,815 of S. lycopersicum to encode for neuronal acetylcholine receptor subunit alpha-5.