Insect-damaged Arabidopsis moves like wounded Mimosa pudica (PNAS)

Stroking leaves of the sensitive plant Mimosa pudica causes them to fold inwards, but when touched more aggressively the leaf petioles and petioles of distal untouched leaves collapse dramatically downwards (as seen in this video); the propagating electrical signal is called the slow wave potential. Kurenda et al. investigated the mechanistic underpinnings of this signal, which can also be recorded in wounded Arabidopsis leaves. The authors measured electrical currents and petiole movements in leaves being wounded by caterpillars as well as nearby leaves. They found that midvein damage led to leaf-to-leaf electrical signaling, and that in irregular xylem (irx) mutants the electrical signal was abnormal. As yet, the relative contribution of pressure changes in or around the xylem versus signals carried within the xylem cannot be ascertained. (Summary by Mary Williams) Proc. Natl. Acad. Sci USA