“…Auxin, a plant hormone that bears a striking similarity to serotonin, is a positional signal in several plant patterning events (Sabatini et al, 1999;Vroemen et al, 1999;Baluska et al, 2003;Friml, 2003;Barlow, 2005) and is involved in establishment of bilateral symmetry in plants ( Lee and Evans, 1985;Liu et al, 1993;Zgurski et al, 2005). Indeed, many of the same players that have been implicated in left-right asymmetry (K ϩ channels, plasma membrane H ϩ flux, cell membrane transporters, and gradients of serotonin/auxin, regulatory roles of pH, fusicoccin, etc.)…”