Question

Q: What happens if water is lost through transpiration more quickly than it is absorbed by the root hair ?

Answer 1

Dear student,
The plant can exert strong control over the rate of water loss through varying stomatal apertures.
Stomates respond to environmental factors such as light, temperature and relative humidity to ensure that the plant is making the best use of its resources to photosynthesise and grow. This usually means that under well watered conditions stomates respond to light, being open during the day and closed at night
When plant roots can no longer absorb enough water to satisfy transpiration from its leaves, it begins to dehydrate. At this point the stomates can over-ride photosynthesis and close down for certain parts of the day to avoid further water loss.
Under extensive water stress where the plant is unable to rehydrate at night, the stomates will remain closed all day. While this is very effective in preventing water loss.
Regards