Functional characteristics and distribution of microorganisms in saline and alkaline soils and their probiotic effects: a review
摘要
With more than 833 million hectares of saline soils worldwide, which are found primarily in arid and semiarid regions, soil salinisation poses a serious threat to global food security and agricultural development. Therefore, a variety of saline soil improvement strategies, including physical, chemical, hydrological and biological methods, have been developed. These methods offer the possibility of rehabilitating saline-alkaline land by improving soil properties, reducing salt concentrations, and promoting plant growth. Among them, the use of microorganisms is considered to have great potential. The microbial communities in saline–alkaline soils are complex and diverse and include saline-tolerant and salinophilic microorganisms that adapt to high-salt and high-alkaline environments by regulating gene expression and altering metabolism and osmotic balance; these microorganisms play important roles in balancing soil ecosystems and maintaining soil fertility. In addition, plant growth-promoting rhizobacteria (PGPR) can increase plant tolerance to saline and alkaline stress and promote plant growth through various mechanisms, such as phytohormone modulation, osmoregulation, antioxidant defence enhancement, and improved nutrient availability. This review systematically summarizes the current understanding of these microbial adaptation mechanisms and their probiotic effects, highlighting the potential for developing efficient microbial fertilisers for the sustainable use of saline soils and the enhancement of agricultural production.