Calcium concentrations in leaf cells signal when the carnivorous plants should snap shut
A Venus flytrap’s short-term “memory” can last about 30 seconds. If an insect taps the plant’s sensitive hairs only once, the trap remains still. But if the insect taps again within about half a minute, the carnivorous plant’s leaves snap shut, ensnaring its prey.How Venus flytraps (Dionaea muscipula) remember that initial touch has been a mystery.
Scientists know that some plants have a type of long-term memory, says study coauthor Mitsuyasu Hasebe, a biologist at the National Institute for Basic Biology in Okazaki, Japan. One example is vernalization, whereby plants remember long periods of winter cold as a signal to flower in the spring. But short-term memory is more enigmatic, and “this is the first direct evidence of the involvement of calcium,” Hasebe says.