In one video, 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. In more than a dozen videos like this, University of Wisconsin–Madison 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.
The research is published Sept. 14 in the journal Science. Masatsugu Toyota led the work as a postdoctoral researcher in Gilroy’s lab. Gilroy and Toyota, now at Saitama University in Japan, collaborated with researchers from the Japan Science and Technology Agency, Michigan State University and the University of Missouri.
“We know there’s this systemic signaling system, and if you wound in one place the rest of the plant triggers its defense responses,” says Gilroy. “But we didn’t know what was behind this system.”
Read more at University of Wisconsin-Madison
Image: This is Simon Gilroy. (Credit: Bryce Richter/UW-Madison)