Abstract: Due to the effects of global climate change, special habitat, and human disturbance, wetland plants are usually suffered from intermittent or permanent salt stress, bringing in profound effects on their survival, growth, distribution, and reproduction. During the process of long-time adaptive evolution, wetland plants adopted a series of special strategies to acclimate to salt stress. The main strategies are: 1) life history adjustment, e.g., to adjust seed germination time, implement seed dormancy and viviparity, and change reproductive manner to escape from direct salt stress, 2) morphological adjustment, e.g., to adjust biomass allocation pattern, age stem, defoliate, and carnify vegetative organs to isolate the redundant Na+ to the inactive-metabolism shoots or exclude the Na+ from tissues; 3) anatomic adjustment, e.g., to sink stoma, develop aerenchyma, and thicken cuticle and phellogen to maintain normal photosynthesis and respiration; 4) physiological and biochemical adjustment, e.g., to exclude and excrete salt, compartmentalize ions, adjust osmosis, do selective absorption, regulate hormones, and induce antioxidative enzymes to maintain the osmotic equilibrium and eliminate the active oxygen (ROS) in cell; and 5) molecular level adjustment, e.g., to start up many salt-induced genes to regulate the metabolic responses to salt stress. In the future, the studies on the Ca2+-regulation of proline synthesis, adaptive strategies under conditions of variable salt contents, and functional maintenance of root systems should be strengthened.

Key words: Paeonia ostii, Heavy metal, Copper-tailings