Question

What will happen if transpiration completely stops in a plant ?

Answer 1

transpiration is a necessary evil. it cool down the leaf surface of plants and changes osmotic pressure of cells, and enables mass flow of mineral nutrients and water from roots to shoots. so, if transpirtion stops completely the uptake of water will be disturbed resulting wilting in plants which may lead to the death of the plants. 

Answer 2

Transpiration is important as it regulates the temperature of the leaf to prevent it wilting. It also allows a continuous process to occur: as long as water leaves the plant by transpiration, root hair cells can continue to take up water and mineral ions from the soil, and these can be transported around the plant through xylem vessels. So, if transpiration stops, mineral ions will also stop being transferred, meaning that they do not reach where they need to be. For example, potassium ions are needed by enzymes for photosynthesis, so without these, the plant cannot photosynthesise and produce its food (glucose). Without glucose, it cannot respire and so cannot obtain energy to carry out its functions.

Hope this helps!