Suaeda maritima shows morphologically different forms on high and low areas of the same salt marsh. Wetson et al. demonstrate that roots of this halophyte have a constitutively very high activity of lactate dehydrogenase (LDH) regardless of whether they are growing in aerated or severely hypoxic conditions, and not the inducible increase in activity that has been demonstrated in other plants during hypoxia. This high LDH activity is likely to be a factor in the high phenotypic plasticity observed in reciprocal transplants between high- and low-marsh field sites and in simulated tidal-flow tanks in a glasshouse.
