You can think of a plant as a bit like a tower made up of cells instead of bricks. Plant cells are mostly water. If the plant loses too much water through evaporation (or transpiration) and this isn't replaced because you haven't watered it, then the water content of the cells starts to fall. Like partially inflated balloons, they start to lose their shape and strength, becoming "flaccid" or floppy. A tower made of floppy bricks doesn't stand up very well, and is likely to bend over or wilt. Watering the plant will allow the cells to refill and the plant may recover.
Most of the Non-aquatic plants if watered with sea water will wilt due to exo-osmosis.
Because it needs to be watered
Overwatering your plant is almost like drowning it, and if the plant continues to be overwatered, the roots might start to rot.
The obvious one is lack of water, but if the plants do not recover when watered there are a multitude of other reasons. Viruses and diseases are common causes, in which case the plants need to be pulled up and destroyed to prevent the spread of infection. Also, grubs can bore into individual stems and cause them to wilt.
because the reason that some plants stay upright is that the cels are filled with water until they are rigid. this is called a turgid plant cell. and when they are not watered these cells cannot maintain a turgid state and this will cause the plant to loose its shape or form.
Alll plants need to be watered and need roots..
If plants are not watered, they will eventually dry out and wilt. This can lead to serious damage and eventually death of the plant. Water is essential for plants to carry out vital functions such as photosynthesis and nutrient uptake, so without water, they are unable to survive.
Joe watered the garden; however, the plants did not grow.
why do plants droop when no water
They can and do
The vacuoles are larger in plants and not so large in mammals. They tend to try to retain more fluid for survival and when that amount is depleted, it is far more noticeable and they appear wilted until they can rejuvenate through rain, ground water et cetera.
During day time when transpiration occurs watering of plants removes the air from the soil and in the abscence of oxygen root cells can not respire aerobically, hence uptake of water is affected. When the loss of water due to transpiration is not compensated by absorption of water by the roots, wilting is observed in these plants.