Seminar: Simon Gilroy,”Do plants feel pain: systemic signaling in Arabidopsis”
November 20 @ 4:00 pm - 5:00 pm
Department of Botany
University of Wisconsin at Madison
Title: “Do plants feel pain: systemic signaling in Arabidopsis“
Plants sense local biotic and abiotic stresses and transmit the resulting cellular signals throughout the plant body. For example, in response to wounding of a leaf, plants trigger production of the stress hormone jasmonic acid (JA) in distant unwounded leaves within a few minutes. However, how plants process information on local stimuli and then transfer this message rapidly throughout the plant body remains poorly defined. Using Arabidopsis expressing genetically-encoded Ca2+ indicators we have visualized a plant-wide signaiong system based on changes in the Ca2+ concentration within cells ([Ca2+]c). Mechanical wounding in one leaf causes a [Ca2+]c increase in the wounded region within one second and subsequently this [Ca2+]c increase is transmitted to distant target leaves within 1-2 minutes in a pathway focused on the phloem. This [Ca2+]c transmission pattern resembles the primary vascular connections between leaves and its spatial and temporal characteristics suggest [Ca2+]c is a systemic wound signal triggering plant-wide wound responses. Blocking plasmodesmatal conduction inhibits spread of the signal once it has arrived in target leaves but rapid organ-to-organ signaling is unaffected. These rapid, long-range systemic changes are disrupted in mutants in the Glutamate Like Receptor channels and can be mimicked by application of glutamate, the amino acid ligand for these channels. These results suggest that glutamate released upon cell damage triggers a systemic Ca2+ signaling network that acts to elicit both rapid cell-to-cell communication as well as a long-range communication via the vasculature within the wounded plant.
Host: Larry Griffing