Plant Stress Responses to Saline and Alkaline Conditions

Plants exposed to saline and alkaline soils face combined challenges of osmotic imbalance, ion toxicity and elevated pH. High concentrations of sodium and bicarbonate ions disrupt water uptake, nutrient acquisition and cellular homeostasis, while alkaline conditions precipitate essential minerals and impair metabolic enzymes. In response, plants deploy morphological adaptations such as reduced leaf area and modified root architecture, physiological adjustments including osmolyte accumulation and stomatal regulation, and molecular mechanisms comprising ion transporters, pH‐regulating pumps and antioxidative enzymes. Signalling networks integrating calcium, reactive oxygen species and phytohormones orchestrate transcriptional reprogramming of stress‐responsive genes. Understanding these multifaceted responses has global significance for crop improvement in saline–alkali–affected regions, enabling targeted breeding or biotechnological interventions to enhance yield stability under adverse soil conditions.

Research from Nature Portfolio

Recent studies have elucidated genetic and hormonal controllers of saline–alkaline tolerance. In maize, a natural variant of an EF‐hand Ca2+‐binding protein governs Na+ homeostasis under NaHCO3 stress by triggering its own proteasomal degradation, which in turn elevates plasma membrane H+‐ATPase activity and SOS1‐mediated Na+/H+ exchange to extrude sodium. Another investigation demonstrated that jasmonic acid pretreatment in maize seedlings mitigates Na+ accumulation and oxidative damage by stimulating antioxidant enzymes and the glyoxalase pathway, thereby preserving cellular redox balance and growth under high pH stress. Together, these findings highlight pivotal regulators in ion transport and stress signalling that can be harnessed to engineer crops resilient to saline–alkaline environments.

Plant Stress Responses to Saline and Alkaline Conditions publication trend

The graph below shows the total number of articles in plant stress responses to saline and alkaline conditions across all publications each year (not limited to Nature Index journals).

Technical terms

Saline stress: Physiological disturbances caused by high concentrations of neutral salts (e.g., NaCl) in the soil.

Alkaline stress: Adverse effects of high soil pH and carbonate/bicarbonate ions on nutrient availability and enzyme function.

Osmolytes: Compatible solutes (e.g., proline, soluble sugars) that stabilise cell turgor and protect macromolecules under osmotic stress.

Reactive oxygen species (ROS): Highly reactive molecules (e.g., H2O2, superoxide) formed under stress that can damage proteins, lipids and DNA.

Plasma membrane H+‐ATPase: Proton pump that establishes electrochemical gradients driving nutrient uptake and pH regulation.

Na+/H+ antiporter: Membrane transporter exchanging cytosolic Na+ for extracellular H+, crucial for sodium extrusion.

EF‐hand motif: Helix–loop–helix structural domain that binds Ca2+ and mediates calcium signalling.

Glyoxalase system: Enzymatic pathway detoxifying methylglyoxal, a cytotoxic by‐product of glycolysis.

Jasmonic acid: Lipid‐derived plant hormone that regulates stress responses and defence gene expression.

References

1. Natural variation of an EF-hand Ca2+-binding-protein coding gene confers saline-alkaline tolerance in maize. Nature Communications (2020).
2. Jasmonic acid ameliorates alkaline stress by improving growth performance, ascorbate glutathione cycle and glyoxylase system in maize seedlings. Scientific Reports (2018).
3. A natural variation in SlSCaBP8 promoter contributes to the loss of saline–alkaline tolerance during tomato improvement. Horticulture Research (2024).
4. Ethylene increases the NaHCO3 stress tolerance of grapevines partially via the VvERF1B‐VvMYC2‐VvPMA10 pathway. Plant Biotechnology Journal (2025).
5. Response Mechanisms of Plants Under Saline-Alkali Stress. Frontiers in Plant Science (2021).