Date: 13th November 2019
Title: Long-range, rapid calcium signaling in plants
Location: Learning centre 1401, Biocentre 1, Viikinkaari 9
Host: Michi Wrzaczek
Abstract: Plants, unlike animals, do not have the central nervous system, but they can rapidly perceive local environmental stresses such as herbivore attack and mechanical wounding, transmit this information throughout their body and activate systemic defense responses. However, the molecular mechanism underlying such rapid sensory and long-range signaling remains unclear. Here, we show that L-glutamate is a wound signal in plants that leaks from damaged cells/tissues and activates the GLUTAMATE RECEPTOR LIKE (GLR) family of ion channels in Arabidopsis thaliana, resulting in the intracellular Ca2+ transmission via the phloem toward distant organs.
We have developed novel imaging devices (e.g., wide-field fluorescent imaging system) to visualize plant sensory responses in real time. Recently, we produced Arabidopsis thaliana expressing highly-sensitive calcium/glutamate biosensors (e.g., GCaMPs and iGluSnFR), which enables high-resolution cytosolic calcium and apoplastic glutamate imaging in the entire plant. Using these unique imaging technologies, we have been trying to clarify the molecular mechanisms of calcium-based rapid systemic resistance responses against insect attack/mechanical wounding.