Osmosis is the movement of water through a membrane. Plant cells have membranes which water can pass through, therefore osmosis can occur through the root cells of plants. Typically, plants have small amounts of salts in the in them. Water has a tendency to move towards the side of the cell membrane that has more salt. So in normal conditions, the plant is just a little bit saltier than the soil. Water will move from the soil into the saltier plant. If you add salt to the soil so it is saltier than the cells of the plant, the water will start moving out of the plant back into the soil. The plant will dry out unless it has some way of increasing its salt content.
Some plants can survive higher concentrations of salt in the soil and might not be affected.
Some plants might need saltier soil. If the plant contains a lot of salts but the soil isn't salty, water will move quickly into the root cells and burst the cells.
Some plants can survive higher concentrations of salt in the soil and might not be affected.
Some plants might need saltier soil. If the plant contains a lot of salts but the soil isn't salty, water will move quickly into the root cells and burst the cells.