Studies on the Mechanism of Salt Tolerance in Salicornia europaea. L. : I. Changes in pH and osmotic pressure in Salicornia plants during the growth period

Abstract

Salt stress is one of important subjects in recent agriculture. Salicornia europaes L. is well used as a comparative plant of salt resistance for many crops. However, there is no detail data for mechanism of salt resistance in Saliconia plants. In the present work, changes in growth, pH and osmotic pressure were investigated at the organ level durins at the organ level during the growth period of wild Salicornia plants. Further, glycinebetaine in the plants at the end of growth stage was determined. Plants of Salicornia around Lake Notoro-ko in the eastern region of Hokkaido, Japan germinated in the ground at the end of March. The fresh weight and the length of the aerial and root portions of the plants increased most between the end of May and the end of August. The plants bloomed at the end of July, and plants gradually changed color from green to red after the end of August. The pH in stems and branches of the plants increased from pH 7.6 to pH 8.8 during the growth period. Also, osmotic pressure in stems and branches of the plants increased remarkably from about 650 mOsm·Kg^-1 to 2, 600 mOsm·Kg^-1 throughout their growth period. Further, glycinebetaine was found in tissues of the aerial and root portions. These results of the accumulation of organic solutes in the cells suggests an osmotic regulatory mechanism.