Signal Transduction & Enzymatic Digestion
The rapid closure of the Dionaea muscipula trap is triggered by mechanosensation. When trigger hairs are stimulated, mechanosensitive ion channels open, generating an action potential (AP).
This electrical signal propagates across the lobes. It requires two stimuli within roughly 20 seconds to trigger the trap, a mechanism that functions as a short-term memory to prevent false alarms (e.g., rain). The closure is driven by a rapid change in turgor pressure and elastic instability.
Once the prey is secured, the plant forms a hermetic seal. The gland cells begin secreting an acidic fluid (pH ~2.5) containing a variety of hydrolases.
The end products of digestion (amino acids, ammonium, phosphate) are absorbed via specialized transporter proteins (e.g., H+-dependent transporters) located in the plasma membrane of the gland cells. This nutrient influx directly regulates the expression of further digestive enzymes.