Salinity is one of major threats to modern agriculture. The problem of soil salinization is especially important for the agricultural areas suffering from water scarcity and inadequate irrigation. This type of environmental stress can severely reduce crop yield since it inhibits and impairs plant growth and development. During evolution, a wide range of adaptation strategies and tolerance mechanisms have evolved in plants to survive in harsh saline environments. Moreover, some other eukaryotes such as lower plants, fungi and animals demonstrate outstanding capabilities to adapt to saline conditions. The deep knowledge of these tolerance mechanisms of halophytes, halophytic crop relatives and other living organisms could be a useful tool for new crop breeding strategies and genetic engineering. The study of adaptation strategies to high salinity including gene networks involved in these process in different plant species and other organisms may help to develop and transfer salt tolerance to the major agricultural crops.