Question

Plant physicology question:

How do water conducting cells in xylem prevent catastrophic damage from embolisms? Mention structures to help minimize damage of embolisms.

Answer 1

Embolism is the blockage of conducting cells of xylem. Conducting cells are generally tracheary elements (xylem vessels and tracheids). If plant has no method to overcome embolism upper plant parts will die due to deficiency of water. Conduction through xylem is the only way to make water available to upper parts.

Tracheids and vessels in xylem are interconnected throught porous lateral walls. If one of the vessel or tracheid get blocked, then water enter into the adjacent conducting strand and move upward. Then again water comes back into the same strand. This pathway provides more resistance to water conduction but it is helpful in overcoming embolism.

Pores in the walls of tracheary elements are the major structures which help in minimising the damage due to embolism.