Seasonal accumulation pattern of pinitol and other carbohydrates in Limonium gmelini subsp. hungarica

Concentrations of the main soluble carbohydrates were measured in leaf and root samples of Limonium gmelini subsp. hungarica (Plumbaginaceae), a species native to the Hungarian inland salty areas. Samples were collected between March and October, from plants growing in their natural habitat. D-pinitol was identified as a significant component of the carbohydrate pool. The seasonal changes in the leaf pinitol concentration were dependent on different stress factors such as decrease of soil water content, low temperature, and leaf sodium concentration. A five-fold increase in the shoot D-pinitol values were observed between mid-April (15 μmol g−1 dw−1) and August (78 μmol g−1 dw−1) concentrations. In the roots, pinitol concentration was relatively low and increased only moderately in the summer. No significant diel changes in the concentration of pinitol were observed except during the time of intensive leaf growth in the spring. The possible functions of pinitol in L. gmelini are discussed.