Mechanisms of Plant Tolerance to Salt-Alkali Stress: A Functional Trait-Based Perspective

Abstract

Soil salinization and alkalization are major abiotic stresses limiting global crop productivity. Salt-alkali stress imposes combined effects of osmotic stress, ion toxicity, oxidative stress, and high pH on plants, disrupting membrane integrity, inhibiting photosynthesis, and impairing nutrient uptake. Plant tolerance to such stresses is a complex quantitative trait controlled by multiple genes, involving various physiological and morphological adaptation mechanisms. Functional traits play critical roles in plant adaptation to saline-alkaline environments. This review synthesizes current knowledge on the physiological mechanisms of plant responses to salt-alkali stress, emphasizing functional trait-based adaptation strategies, and analyzes the effects of salt-alkali stress on plant growth, biomass allocation, nutrient uptake, and photosynthesis through specific case studies. Research indicates that a single indicator cannot accurately reflect plant adaptability to salt-alkali stress; instead, multiple functional traits should be integrated for scientific evaluation. Understanding these mechanisms provides a theoretical basis for breeding stress-tolerant crops and managing agricultural ecosystems under changing environmental conditions.