Besides low availability of Fe, plants experiencing saline–alkaline stress resulting from high Na+ concentrations encounter problems such as osmotic imbalance and ion toxicity (Yang et al., 2007; Wang et al., 2012). Na+ toxicity is often associated with the systemic dysfunctions of uptake and distribution of K+ in plants (Shabala and Cuin, 2008; Anschütz et al., 2014). Numerous studies have indicated that saline-tolerant plants can effectively control intracellular K+ and Na+ balance, which is required for the stability of membrane potential and enzymatic activities (Anschütz et al., 2014; Zhang et al., 2016). The cytosol of saline-tolerant plants can maintain high K+ and low Na+ under salt stress. Recently, ABA has been shown to regulate the expression of tonoplast Na+/H+ antiporter genes, thereby modulating K+ and Na+ homeostasis (Fukuda et al., 2011).