Abstract:
Soil salinization poses a serious threat to global sustainable agricultural development and food security, affecting approximately 20% of irrigated farmland worldwide. China has about 100 million hectares of saline-alkali land, and the development and utilization of such land hold significant strategic importance for ensuring national food security. Rice, an ideal crop for ameliorating saline soils, offers the most cost-effective approach to utilizing saline land through genetic improvement of its salt tolerance. As a salt-sensitive crop, rice is adversely affected by high soil salt concentrations at key growth stages, including germination, plant growth, and panicle development, leading to reduced yield, inferior quality, and even plant death in severe cases. Identifying salt-tolerant rice materials and mining salt-tolerant genes provide a theoretical foundation for molecular marker-assisted selective breeding, thereby enhancing rice salt tolerance and shortening the breeding cycle of salt-tolerant rice varieties. Currently, through linkage analysis, genome-wide association studies (GWAS), and super pan-genome strategies, over 1 000 salt-tolerance QTLs, such as
Saltol,
qST4, and
qSKC5-1, have been identified across the entire growth period of rice. To date, more than 400 salt-tolerant genes have been cloned in rice, encompassing genes encoding ion transporters, transcription factors, enzymes, and other functional proteins. Although progress has been made in mining salt-tolerant genes in rice, few genes have been cloned through forward genetics; individual gene effect values are relatively low, and only a limited number of genes can be directly applied to salt-tolerant rice breeding. Research on salt-tolerant genes in rice is increasingly focusing on detailed mechanistic insights and innovative technological integration. Future studies should adopt multidisciplinary perspectives, integrating single-cell transcriptomics, metabolomics, and epigenomics, to accelerate the mining of salt-tolerant genes and the study of salt tolerance mechanisms, thereby providing more genetic resources and a theoretical basis for salt-tolerant rice breeding.