Transpiration

• Movement through a xylem occurs by evaporation od water from leaves and cohesive and adhesive nature of water
• Water potential gradient moves water from the soil to the atmosphere via plant cells
• Transpiration

  loss of water vapour via stomata by diffusion
• Transpiration Stream

  movement of water from roots to the leaves
• Transpiration Provides,

  • evaporative cooling
  • uptake of mineral ions
  • turgor pressure provides support to leaves
• Environmental conditions can cause water pot gradient between air inside leaves and outside, therefore water diffuses out of leaves through stomata.
• Vapor lost lowers water pot in air spaces around mesophyll, and water within mesophyll evaporates into air spaces creating Transpirational Pull
• Movement of water though cell walls of plant occurs by apoplast pathway
• Movement of water from cytoplasum occurs via symplast pathway
• Transpiration Stream

  The pull of water moving through mesophyll cells, takes water away from xylem vessels, causing water to move up the xylem to replace lost water by adhesion and cohesion.
• Transpiration is mostly controlled by the guard cells