Abstract
Salsola komarovii Iljin is an amaranthaceous C4 halophyte (NADP-ME type) that grows on coastal sand ground in Japan. Glycine betaine is a compatible solute, which functions in adjusting osmotic balance and protecting enzymes, and synthesized in response to salt stress in S. komarovii. In this study, to examine the physiological role of glycine betaine in the salt tolerance of S. komarovii, we have investigated the tissue localization of glycine betaine synthetic enzymes in the plants grown under control and saline conditions.
The last step of glycine betaine biosynthesis is catalyzed by betaine aldehyde dehydrogenase (BADH). Western blot analysis of BADH protein showed that the expression level of BADH protein was increased by salt treatment in the leaves. In the immunolocalization experiment of BADH protein in the leaves, the signal of BADH protein was detected in vascular tissues under control condition, and in vascular and bundle sheath tissues under a saline condition. These results indicate that production and/or accumulation of glycine betaine in vasucular and bundle sheath tissues may be important for the salt tolerance of S. komarovii.
