Electrical communication in the venus flytrap

• some plants possess communication systems that enable them to coordinate the different parts of their bodies
• the venus flytrap is a carnivorous plant that gets it's supply of nitrogen compounds by trapping and digesting small animals
• specialized leaf is divided in two two lobes on either side of a midrib
• inside of loves is red and has nectar-secreating glands on the edges to attract insects

  • each lobe has 3 stiff sensory hairs that respond to being touched
• if an insect touches one of these sensory hairs with enough force, action potentials are stimulated which then travel very fast across the leaf
• these action potentials cause the two loves to fold together along the midrib capturing the insect
• diagram

  
• how venus flytrap closes

  • if one touched with enough force, calcium ion channels in cells at the base of the hair are activated
• when channels open, calcium ions flow in and generate a receptor potential
• if two of the sensory hairs are stimulated within a period of 30s, or if one hair is stimulated twice during this period, action potentials will travel across the trap and cause it to close
• when trap is open, lobes of the leaf are convex in shape but when triggered, they become concave, bending downwards and causing trap to shut
• this is though to occur as a result of a release of elastic tension in cell wall
• sealing the trap requires ongoing activation of sensory hairs

  • prey trapped inside provides this ongoing stimulation, generating further action potentials
  • Further stimulation of sensory hairs causes calcium ions to enter gland cells where they stimulate the exocytosis of vesicles containing digestive enzymes
  • trap then stays closed for up to a week to allow prey to be digested and nutrients to be absorbed by plants