Proline accumulation pattern in species of an inland saline habitat

Seasonal and diurnal fluctuations were measured in the leaf proline content of three dicot species (Limonium gmelini, Lepidium crassifolium and Campho rosma annua), natives to an inland saline area of Hungary. Proline contents were negatively correlated to the mean monthly temperature in all three sp ecies. All the investigated species accumulated proline in February and/or March, while increases in temperature were followed by a drop in proline le vel by the beginning of April/May. Sodium accumulation in the leaves as wel l as soil water content influenced the amount of proline to a smaller exten t than temperature in all of the investigated species. Accumulation of prol ine did not show significant correlations with the accumulation of sodium i n the leaves. Diurnal pattern of leaf proline content changed during the gr owing season with a decreasing trend at the beginning (April) and increasin g trend at the end (August) of the season.