FIGURE 3.

The salt secretion of the salt gland with a distinct salt crystals on the leaves of Distichlis spicata (A) and Limonium bicolor (B). The photograph in (A) was reproduced from Semenova et al. (2010). The leaf blades of D. spicata exhibited salt crystals on their leaf surfaces after the plants were incubated in 0.55 mM NaCl solution for 20–24 h under conditions that prevented the slightest air flow (Semenova et al., 2010). The photograph in (B) was reproduced from Feng et al. (2014). Leaves of L. bicolor that were treated with 200 mM NaCl displayed distinct salt crystals on the surface of leaves, and the salt secretion rate per single salt gland was 8 ng h^–1, which is equivalent to a 5 mg Na⁺ secretion from a single mature leaf within 24 h after it was treated with 92 mg NaCl (200 mM) per day.