You can see a hungry caterpillar, first working around a leaf’s edges, approaching the base of the leaf and, with one last bite, severing it from the rest of the plant. Within seconds, a blaze of fluorescent light washes over the other leaves, a signal that they should prepare for future attacks by the caterpillar or its kin.
That fluorescent light tracks calcium as it zips across the plant’s tissues, providing an electrical and chemical signal of a threat. Professor of Botany Simon Gilroy and his lab reveal how glutamate — an abundant neurotransmitter in animals — activates this wave of calcium when the plant is wounded. The videos provide the best look yet at the communication systems within plants that are normally hidden from view.