An ATP signalling pathway in plant cells: extracellular ATP triggers programmed cell death in Populus euphratica (pages 893–916)
JIAN SUN, CHUN-LAN ZHANG, SHU-RONG DENG, CUN-FU LU, XIN SHEN, XIAO-YANG ZHOU, XIAO-JIANG ZHENG, ZAN-MIN HU and SHAO-LIANG CHEN
Article first published online: 6 DEC 2011 | DOI: 10.1111/j.1365-3040.2011.02461.x
Extracellular ATP (eATP) acts as a signalling agent in plant growth and defence, but its role in programmed cell death (PCD) is less known. Using a wide range of fluorescence microscopic imaging techniques and non-invasively Ca2+-selective microelectrodes, we elucidated the eATP signalling cascade active in PCD of Populus euphratica cultures. The eATP-induced PCD was mediated by a series of signaling events, such as purinergic receptor activation, intracellular Ca2+ mobilizations (including Ca2+ influx, Ca2+ elevation in the cytosol, Ca2+ release from the vacuole and mitochondrial Ca2+ uptake), mitochondrial hyperpolarization, H2O2 bursts in the mitochondria, cytochrome c release and stimulation of caspase-like proteases. NO is implicated as a downstream component of the cytosolic Ca2+ concentration but plays a negligible role in eATP-stimulated cell death.