Halophytes

• Halophytes

  Plants that live in environments of high soil salinity
• Problems

  • water doesn't move into the plant if the plant's solute concentration is higher than the concentration outside
  • water moves out of the plants via osmosis along a concentration gradient - halophytes lose water due to the high salt concentration in the surrounding soil drawing water from the plant tissue
  • plant growth can be reduced, germination can be hindered, and plants can struggle with a water deficit
  • high levels of salt ions can lead to toxicity and cell death
• Adaptations

  Structural:

  • aerial roots systems called pneumatophores
  • filtration structures in roots
  • salt glands

  Physiological:

  • concentrates and stores salts in vacuoles
  • accumulates salt in leaves or bark
• Types of Halophytes

  • salt accumulators: accumulate and store excess salt in salt glands or central vacuoles
  • salt excluders: exclude salt by ultrafiltration through cell membranes
  • salt accumulators and excluders