Advances in Salinity Tolerance of Soybean: Molecular Mechanism and Breeding Strategy

Soil salinization is a substantial environmental stressor that limits plant growth and development. Soil salinization has, therefore, emerged as a substantial barrier to crop production, particularly affecting soybean production in arable regions. Cultivating soybean varieties with high salt tolerance is an efficient approach for improving soybean production on arable land with soil salinization. The growth and development of soybean plants exposed to salt stress involve numerous physical and molecular regulation networks. Therefore, a comprehensive understanding of the molecular mechanisms underlying soybean salt tolerance is a prerequisite for improving the salt tolerance of current soybean varieties or for breeding new soybean varieties with higher salt tolerance. This review provides a general overview of recent knowledge that may help to understand the molecular mechanisms of soybean responses to salt stress and discusses the potential challenges in salt-tolerant soybean breeding, as well as possible strategies. We emphasize the importance of different genetic resources, especially wild soybeans, for mining new advantageous alleles. Additionally, pyramiding superior alleles and genome editing technologies are excellent tools for accelerating the cultivation of salt-tolerant soybeans.