Root cells accumulate ions of K Na and Cl into the vaculoes

Root cells accumulate ions of K+ Na+ and Cl- into the vaculoes. How might this help the plant resist drying out further?

Solution

The root cells absorb the salts of sodium and potassium from the soil. Though these salts play a very important role in the water relations of the plant excess of salts in the plant will lead to osmotic stress in the plants and to the toxicity .within the plant.the roots have an excellent mechanism to contain the salt levels in the cytoplasm and there subsequent transport to the aerial parts of the plant.excess accumulation of these salts in older parts of the plants may eventually lead to the damage of the cells as these parts are known to have higher transpiration rate.The K + ions are comparatively less toxic and are present in the cytoplasm of the cell and help in the osmotic adjustment.

Hence the excess salts are transported across to the vacuole where they have little effect and play a positive role in the water uptake by the plant and also influence the transpiration .