Figure 1.

Cl⁻ homeostasis in glycophyte plants. Schematic illustration of Cl⁻ homeostasis in glycophyte plants according to the classical view of Cl⁻ nutrition (A), the classical view of Cl⁻ toxicity (B), and comparison with the recently proposed role of Cl⁻ as a beneficial macronutrient in glycophyte plants (C). (A,B) have been made from the data of Cl⁻ contents reported in different plant species, obtained from the review by Xu et al. [5]. Cl⁻ homeostasis as a beneficial macronutrient in glycophyte plants is illustrated in (C), according to the data recently reported [2,18,19,20]. Ci, citrus; Tb, tobacco; Tm, tomato; Ci_e, citrus excluder genotypes; Ci_i, citrus includer genotypes.