Salt secretion in different leaf ages and leaf positions of Limonium bicolor

Abstract

Recretohalophytes can excrete excessive salt from salt glands or salt bladders in order to avoid salt damage. Limonium bicolor, belonged to Plumbaginaceae, is a typical exo-recretohalophyte with salt glands. A differential interference contrast (DIC) microscope and leaf discs secretion model was used in the study to explore the salt secretion of different leaf ages in L. bicolor at the individual level. For a single mature leaf, more salt glands are distributed in the leaf abaxial than leaf adaxial. The total Na+ secretion amount was positively proportional to the leaf age and leaf area. And the Na+ secretion rate per salt gland obviously increased at the beginning and kept relatively stable at late period of leaf development. These results suggested that Na+ secretion rate of L. bicolor were adapted to the leaf age and area.